Textile internship program report

E.G i
Bahir Dar University
Institute of Technology for Textile,
Garment and Fashion Design
Internship Program at
Ayka Addis Textile and Investment Group
By Enquzer Getachew
Duration- 20-Oct-2010 – 7-Feb-2011
Submission Date- 21-Feb-2011

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Institute of Technology for Textile, Garment
and Fashion Design
Internship Program at
Ayka Addis Textile and Investment Group
By
Enquzer Getachew
Copyright © 2012 by Enquzer Getachew
DEPARTMENT OF TEXTILE ENGINEERING
Institute of Technology for Textile, Garment and Fashion Design
Bahir Dar
Ethiopia

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PREFACE
At the outset, this paper is written during Internship Program at Ayka Textile and Investment Group
arranged by Bahir Dar University, Institute of Technology for Textile Engineering, Garment and Fashion
Design.
The material has been prepared mainly as a Report but anybody who wants to have a general view of
textile machineries and there working principle can benefit from it; with this in mind, most of the information
given is compiled form four years of Textile education and several resources gathered form the company. It is
tried to cover Spinning, Knitting and Dyeing Departments in Ayka. Hopefully the reader would find the
material useful.
It is tried to convey as much information as possible. Since production data are tentative some
information might change over time, hence it should be noted that all the information given are gathered with in
the time frame of four months.
Enquzer Getachew
Textile Engineering Department
Institute of Technology for Textile, Garment and Fashion Design
Bahir Dar
Ethiopia.
20-Oct-2010 – 7-Feb-2011

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Table of Contents
PREFACE..........................................................................................................................................................................3
A) SPINNING
1 Row Material
1.1 Introduction ............................................................................................................................................8
1.2 Problems Observed...............................................................................................................................10
1.3 Recommendations.....................................................................................................................................10
2. Textile Testing and Quality Control
2.1 Introduction to Testing..........................................................................................................................11
2.1.1 Objectives of Testing.............................................................................................................11
2.1.2 Some of the most important properties to measure .........................................................12
2.2 Lab equipments.....................................................................................................................................14
2.2.1 HVI 900 (High volume instrument)....................................................................................14
2.2.2 USTER® TENSOJET 4 ......................................................................................................15
2.2.3 USTER® AFIS PRO (Advanced Fibre Information System)........................................17
2.2.4 Uster 4......................................................................................................................................17
2.3 Colour Calibration (Uster® colorimeter 750).......................................................................................18
2.4 Quality Monitoring...............................................................................................................................19
2.5 Problems and Recommendations in lab ...............................................................................................20
3. Blow Room
3.1 Introduction ..........................................................................................................................................21
3.2 Blow room machines in Ayka................................................................................................................22
3.2.1 ROBOT or UNIFLOCK ( Reiter model A10 Herman machine)..................................22
3.2.2 CAGE CONDENSOR (Reiter model)..............................................................................23
3.2.3 Uniclean (Reiter model B11) ................................................................................................23
3.2.4 Blending feeder (Reiter model B34)....................................................................................24
3.2.5 Auto-mixer (Reiter model B )................................................................................................25
3.2.6 Horizontal opener (UNIFLEX MACHINE, Reiter model B60) ............................................26
3.2.7 UNIBLEND MACHINE( REITER MODEL B78)........................................................27
3.3Problems observed in Blow ROOM.......................................................................................................29
3.4 Recommendations.....................................................................................................................................29
4. Card (Tarak)
4.1 Introduction...............................................................................................................................................32
4.2 Operating Principle................................................................................................................................34
4.3 Problems Observed...............................................................................................................................36

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4.4 Recommendations....................................................................................................................................36
5. Draw Frame (Jer)
5.1 Introduction..........................................................................................................................................37
5.2 Parts of Draw Frame..............................................................................................................................38
5.3 Operating Principle................................................................................................................................40
5.4 Problems Observed and Recommendations.........................................................................................42
6. Unilap and Comber (penye)
6.A. Unilap
6. A.1. Introduction.............................................................................................................................43
6. A.2. Operating Principle....................................................................................................................43
6. A.3 The two types of Unilap machines .............................................................................................44
6.B Comber
6. B.1) Introduction..............................................................................................................................46
6. B.2. Operating Principle ...................................................................................................................47
6. B.3. Combing cycle...........................................................................................................................48
6. B.4. Formation of Sliver....................................................................................................................50
7. Roving Frame
7.1 Introduction.........................................................................................................................................51
7.2 Operating Regions ...............................................................................................................................51
7.2.1 Creel.............................................................................................................................................51
7.2.2) Drafting Region........................................................................................................................52
7.3.3 Spindle and flyer ........................................................................................................................53
7.3.5 Pneumatic suction: ....................................................................................................................54
7.3.6 Cone drive transmission ...........................................................................................................55
7.4 Operation Sequence.............................................................................................................................55
7.5 Problems and Recommendations ........................................................................................................56
8. Ring Frame
8.1 Introduction.....................................................................................................................................57
8.2 Principle of operation...............................................................................................................................57
8.2.1Drafting..............................................................................................................................................58
8.2.2 Ring and Traveller...........................................................................................................................58
8.3 Twist............................................................................................................................................................60
8.4 Recommendations ................................................................................................................................61
9. Winding
9.1 Introduction ..........................................................................................................................................63

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9.2 Operating Regions.....................................................................................................................................65
9.2.1 Drum winding ...............................................................................................................................65
9.2.2 Splicing............................................................................................................................................65
9.2.3 Yarn Waxing ..................................................................................................................................66
9.2.5 Yarn Clearing.................................................................................................................................66
9.2.4 Compensation type (Gate type) tensioning device ..................................................................67
9.3 Steaming (Walker APS 7 machine)........................................................................................................67
9.4 Recommendations ................................................................................................................................68
10. Rotor
10.1 Introduction ........................................................................................................................................69
10.2 Basic Principle of Open-End Spinning .................................................................................................69
10.3 Working principle................................................................................................................................71
10.4 Problem and Recommendation...........................................................................................................74
B. KNITTING
2.1 Introduction ...........................................................................................................................................77
2.2 Basic Structure Circular Knitting Machine............................................................................................78
2.2.1 The Yarn Holding System......................................................................................................78
2.2.2 Yarn Feeders ............................................................................................................................79
2.3 Stitch Formation Motions........................................................................................................................80
2.4 Take-down and Winding Motions..........................................................................................................83
2.5 Quality control.......................................................................................................................................84
2.6 Problem Observed and Recommendation...............................................................................................90
C. DYEIING
1.1 Introduction ...................................................................................................................................93
1.2 Dyeing Procedures..........................................................................................................................95
2 Mechanical finishes................................................................................................................................98
2.1 Compacting and Shrinkproofing...............................................................................................98
2.2 Sanforization ..............................................................................................................................98
2.3 Raising .......................................................................................................................................... 92
3 Printing .......................................................................................................................................................93
4 Analysis of Water ......................................................................................................................................95
Conclusion......................................................................................................................................................................96
Refrences.........................................................................................................................................................................97
Appendix.........................................................................................................................................................................98

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A) SPINNING
The term spinning means to ―rotate‖. A set of fibres arranged in a continuous strand is rotated to form yarn
at he last stage of yarn formation and thus the term spinning. The objective of spinning is to produce a yarn. If
the single yarn is untwisted they will disintegrate into fibres. Two or more single yarns may further be combined
into a single strand and twisted together to make doubled/ twisted yarn.
In short staple spinning process, fibres having a staple length of about 20 to 40mm are converted to yarns. Or
broadly fibre shaving characteristics similar to cotton, particularly with regard to length are converted to yarn.
Blow room- fibres arrive in the spinning factory in the form of bales of fibres which are highly compressed
and there is no particular order in the arrangement of fibres in the bales. The bales of fibres contain non fibrous
material (trash). The major function of blow room is to clean the feed material and open the material so that the
next machine can take over.
Card- The material form blow room is fed to the card. The feed material for card can be either in a lap form
or through ducts pneumatic transport. The function of card is to individualize, further clean and arrange the
fibres in a more or less parallel form and deposit it in a sliver can.
Draw Frame- card sliver is passed to the first passage (Breaker draw frame) of draw frame where 6 to 8
slivers are red to a single drafting system and are drown together. Again the out put of the first path is fed to
another path (Finisher draw frame) set 6 to 8 slivers to double or to even out the variations present in card
sliver so that the out put will be more uniform, hooks hat are formed in card are removed and to improve
evenness of the output.
Comber- is an optional process which is used when a high quality product is demanded. Short fibres are
removed and other defects are improved. The feed material for comber needs to be prepared with comber
preparatory machines like Unilap machines which are called Comber lap. Combing process removes a
significant amount of waste which is called Comber Noil. The output of comber machine is called Comber
Sliver.
Roving Frame- finisher draw frame sliver is drafted to the required thickness which can be handled
efficiently by the next process. A protective twist is added to the material and wound into a package. The out
put is called roving. The drafting system is done by ―top arm‖ drafting system and twisting operation is carried
out by spindles and flyers.
Ring Frame- The roving is drafted, twisted and wound into a package. The drafting system again carried out
by Top arm drafting system and twisting is done by spindle and traveller. The package is called Ring Bobbin
or Ring Cop. Apart form Ring frame Spinning can be carried out by Rotor Spinning machine.
Cone Winding- the yarn from ring spinning machine is in the form of small packages containing short length
of yarns. These small packages are fed to a winding machine in order to get larger packages. The output is
conical package called Yarn Cone. During winding quality improvement is possible by clearing yarn defects
while winding.

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1. Raw material
1.1 Introduction
In yarn production, row material forms a quite substantial part of the cost of production. Row material
quality, in a figurative sense, is responsible for about 90% of the yarn quality - in other words, whatever else is
done, without proper raw material quality, obtaining satisfactory yarn quality is almost impossible. Thus
ensuring good raw material quality assumes a very high level of importance ensuring at the same time the costs
are maintained at the lowest possible levels. Raw material influences productivity & quality to a very large extent.
Ayka textile factory purchases its row materials from different ginning factories both from domestic and
foreign ginning companies.
Organic cotton from Turkey provided by Mustafa cotton ginning company
Inorganic cotton from local markets like – upper Awash/Omo valley- Amibara ginning factory
Arbaminch ginning fatory
Cotton from Mohammed Amiru
Cotton from Endirs in Awash
Middle Awash –Sami ginning factory, Lucy ginning factory
Cotton from Bukina faso
Cotton from Nazilli in Turky
Manufactured row materials like viscose and Pollster form India
Dyed cotton from dyeing department
Here there is a significant difference between organic and inorganic cotton. In addition to Organic cotton,
as the name implies is grown naturally with no synthetic fertilizers applied like using manure. While Inorganic
cotton is grown using man made fertilizers like urea and ammonium nitrate.
Organic implies both the nature of growing and the process. In addition to naturally growing cotton, it
includes natural way of production. This means natural place to wok for the workers. Textile companies tend to
be loud inside with huge machineries with there rolling parts and also exposure to dust and fly. Natural way of
work means all workers are provided with the necessary protection against dust and other breathable health
hazards like cotton fly. In addition, it requires the sound level they are exposed to be carefully calibrated so that

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there is opposite correspondence with there working hour or are provided with proper insulation. Workers wok
the natural duration of time which is globally accepted hours i.e. 8hrs
Inorganic way of production which Ayka is following excludes most of the organic provisions. Not only
there is no limit for sound levels which the workers are exposed to, working hour is extended to 12Hrs.
This difference in way of production has effect in cost of cotton in that organic cotton is at least 15%
more expensive than the inorganic one.
Row material is purchased in a form of bale form different places so the quality and quantity differs form
one bale to another. So there must be a way to identify them. There is a paper with list of identifying queries on
each bale to do that. The includes
1) Batch no-which identifies the pat of farm the cotton is harvested from
2) Bale no- no given in sequence for each bale
3) Lot no- an identification number for that bale. Ayka give different lot no depending on from what
country the bale came. For example bale form any part of Ethiopia has the title ―et‖ fallowed by a
number, for polyester M-33/P2006.
4) Gross weight – weight of the bale with the packaging material
5) Net weight - weight of bale without packaging material
6) Colour- colour value of row material
7) Quality- two set of numbers each designating diameter and staple length consecutively.
E.g. 1.2*38
8) 8 Year- time where the bale is pressed
The net weights of bales vary form 180 to 250kgs per bale. For example Ayka imports white cotton with weight
ranging from 205 to 215kgs. Synthetic products ranging form 202 to 220 kgs.
Bales are stored in storage room with no proper temperature and humidity. And are transported form store
room to spinning department using forklift.
Whenever there is requirement of row material form store room there is a list to be filled which include in
which the amount is determined by stock manager. Spinning department has its own store room so row material
can be moved when ever it is needed.

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1.2 Problems Observed
1. There is no systematic arrangement of bales and poor space utilization Fig 1.1 A. The bales at the
bottom get pressed highly which causes high inter fibre friction. This leads to uneven bale opening. It
also causes high temperature build up around the bales.
2. Putting waste with clean row material Fig 1.1 B. This causes contamination of the clean cotton bales
since cotton bales must be stored open to the environment for accumulitization (a process of natural
adjustment of fibres with the environment) of the bales to the temperature and humidity the room.
1.3 Recommendations
Having proper material storage is a key point in to minimize processing difficulties and also to produce quality material.
Row material has a significant share in cost of production; hence it should be stored properly.
There are many ways for storing bales, the 5s system is the most suitable one. 5s system a monogram to arrangement
based on sorting (eliminating unnecessary equipments), Setting in order, Sweeping cleanness of the room, Standardizing
(identical or consistent or symmetrical arrangement), Safety (the basic thing for both operators and row material). Based
on this and the most likely quantity need of the factory, easy access and easy loading and unloading, reusable waste is
placed closer to the door and is covered partially with a plastic to avoid contamination by dust, and man made fibers are
stored closer to it since they are stored covered, is the following top view of store room is recommended. The air
condition system is recommended on Draw frame problems since its effect can be mainly seen there.
Fig 1.1 Problems in method of Storage
A B
Cotton bales
Man made fiber bales
Trash containing bales
Movement path for operators
Door
Plastic cover
Store room wall

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2. Textile Testing and Quality Control
2.1 Introduction to Testing
 Testing can be a valuable aid to those engaged in production, distribution and consumption.
 Testing instruments can not make decisions! A human being has to study, analyse, interpret and device
means of using the test results to the maximum extent possible.
 Just because a material has been tested does not enhance the technical quality of the (tested) material!
(Most of the tests are destructive; some tests though not destructive, may deteriorate the quality!)
 The person in charge of a textile mill laboratory should be a ―first-class‖ textile technologist. Further, he
should be a part-scientist, part-statistician, part-technologist and part-diplomat – all these combined in
one person!
 The variety of textile testing instruments is quite large. They range from very simple to quite complex;
employ a wide range of principles; cost almost nothing to hugely expensive.
2.1.1 Objectives of Testing
Selection of raw materials
All the natural fibres have properties that vary very widely. Similarly, yarns (raw materials for weaving) and
fabrics (raw materials for wet processing and finishing and garment factories) also have wide range of
properties, which too vary quite widely. Selection of raw materials is an important technological function; this
invariably requires testing. In the case of man-made fibres, testing of properties is usually not done at the level
of textile mill, as they are tailor-made; however, occasionally, even the man-made fibres need to be tested.
Process Control
When the process (i.e., manufacturing process) goes out of control, the costs go up, the number of defectives
rise; the wastes go up and so on. To prevent the process going out of control, the output at each stage has to
be tested for relevant properties. When the properties are within the stipulated limits, the process is said to be
within control.
For effective process control, quick results are required - so that production of defective material is stopped as
quickly as possible. Thus, testing laboratory should be as close as possible to the production departments.
Process Development
Many a time, it becomes necessary to carry out tremendous experimental work to arrive at optimum
levels of processing parameters (to give an example). The materials need to be tested at each stage to arrive at
valid conclusions.
Product Testing
When the raw material is properly selected and when the process is controlled tightly, the product is
bound to be with the necessary quality. Unfortunately, this is never completely true! It is quite likely that all
known parameters are quite within stipulated limits and still the quality is not satisfactory. If thus becomes

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necessary to test the final product – to find out whether ‗everything‘ is quite alright, the performance of goods in
actual usage also needs a variety of tests.
In spinning, quality can be achieved only when the following are ensured (apart from the management aspects):
Adequate quality of raw material for the given type and count of yarn
An excellent degree of machine maintenance
Availability of machines which are well-designed and maintainable with reasonable degree of reliance. Poorly
designed machines invariably means poor quality and they are not unknown in the textile field
Correct/optimum choice of machine settings, speeds and process parameters
Quality control schedules (like the frequency of studyes, the scheme of sampling etc) should be drawn
according to the needs of the company
Resources for quality control activities in terms of personnel, equipment, support from the top management,
proper environment for dissemination of information and corrective action without hostility are essential
An adequate system of documentation should be maintained so that information is recorded and maintained
properly for any future reference.
There is a relationship between fibre properties and yarn properties. For this reason the testing of raw fibre
properties is important to the cotton spinning mill to predetermine yarn strength and spinning production
2.1.2 Some of the most important properties to measure
Length
Generally, when a physical characteristic is of interest, the measurement is made and, usually, the
arithmetic mean is calculated. Most likely, in many cases, the standard deviation and the co-efficient variation
are also calculated in order to assess the variation. Sometimes, a histogram is also constructed to observe
visually the distribution in a graphical form.
Interpretation of fineness results obtained by air-flow methods of cotton fibres
Immature and half-mature fibres have lower mass per unit length than mature fibres because of the lower
mass of cellulose contained in the secondary wall; although the thickness of the fibre may be the same. Thus, a
given sample of cotton fibres with a higher level of immaturity will contain more number of fibres for a given
mass than mature fibres. Obviously, the sample with higher level of immaturity would show ‗fine‘ reading
than is actual.
The perimeter of cotton varieties is a genetic factor - i.e. the transverse dimension is an inherited
characteristic which is not affected by growth conditions. However, the growth of secondary wall (in other
words, the maturity) is highly influenced by growth conditions.
A finer reading for a given variety (than is normal for that variety) indicates poor maturity. Thus, micronaire
value is an indicator of maturity under this set of conditions (rather than the fineness in terms of

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micrograms per inch)! Thus, results based on air-flow methods should be carefully considered along with
the maturity of fibres arrived at by other methods.
Neps and Seed Coat Neps
Fibre Neps
The amount of neps in raw cotton depends on the cotton variety or origin and harvesting method. Fibre
neps are generally defined as entanglements of several fibres. Mechanical treatment of the cotton fibres during
harvesting, ginning and opening and cleaning of the fibres in the spinning plant generate them. Neps are
reduced at carding and combing. The amount of reduction highly depends on the machine performance, the
production level and the overall quality that the spinning mill wants to achieve.
Neps do not ―grow‖ on the plant. Seed cotton does not contain any neps. However, as soon as the fibres are
picked – and especially when they are picked mechanically – neps are introduced to the fibres. The amount of
neps further increases in ginning and in opening and cleaning of the spinning mill. The main reduction takes
place during carding and combing. Whereas the amount of neps increases in opening and cleaning, the amount
of trash is reduced. After all, this is the task of the cleaning equipment: Removing the remaining trash particles
and opening the cotton for further spinning preparation.
The cleaning process works best with the cotton being opened. The cotton is transported from one cleaning
stage to the next in the ductwork via air. This process can cause the increase in nep content. The more open the
fibres are toward the transporting air circulation, the more the fibres tend to form neps. Machine manufacturers
have a good understanding of this behavior and will design the opening.
Seed Coat Neps
Seed coat neps are fragments of the cottonseed that still have some fibres attached. They are created mainly in
ginning when the fibres are being separated from the seed. The amount of seed coat neps in raw cotton depends
on the quality and the aggressiveness of the ginning process. The number of seed coat neps can slightly increase
in opening and cleaning. They are mainly reduced at carding. However, the removal of seed coat neps is very
difficult since the attached fibres tend to stick with the fibres in the process.

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2.2 Lab equipments
2.2.1 HVI 900 (High volume instrument)
The speed of the HVI (+High Volume Fibre Test System) instrument allows every bale of cotton to be
tested. The challenge then becomes how to effectively use the information to improve the spinning process. All
cotton has a natural variation of fibre properties. Some of these variations are small but others may be quite
large. This variation is greatest between bales of cotton grown with different seed varieties. We also find variation
of fibre properties within a cotton seed variety. Many factors influence the variation of fibre properties. These
include growth area, climate, planting and harvesting practices. A typical distribution of the length variation of
cotton with a 27-mm staple length is shown below. These types of normal distributions apply to almost all of the
fibre properties measured by the HVI instrument.
HVI Applications
The HVI can be used in a variety of applications in the cotton industry. Some of these applications are
listed below.
Instrument for Measuring Length, Uniformity, Strength, Elongation, Micronaire, Color, and Trash for
Cotton Fibres
Cotton Seed Breeders — Verify progress in attaining goals in development of new varieties of cotton.
Cotton Producers and Government Standards -grading and Classification for use in establishing the loan
value and spot market price of cotton.
Cotton Research —Basic research and investigation of various physical properties of textile fibres.
Working Principle
The HVI 900 system is housed in two floor-standing cabinets: the larger cabinet contains the
Length/Strength Module and the smaller cabinet contains the Micronaire and Color/Trash Modules.
Included with the system are an alphanumeric keyboard, a monitor and a balance. The monitor displays the
menu selections, operating instructions and test results. As tests are completed for each sample, the results
can be transmitted to a printer and/or an external computer system, if available. The HVI 900 system
consists of modules that can be combined in a variety of ways. Your system may include any or all of the
following components: the Length/Strength Module, the Micronaire Module and the Colour/Trash Module.
1 Length/Strength Module
The Length/Strength Module optically determines fibre lengths and associated uniformities. The length,
known as the ―elongation,‖ is calculated by averaging the length of distance the fibres will extend before
breaking. The Strength is determined by measuring the force that is required to break a sample of a known
mass.
The Length/Strength Module of the HVI 900 consists of a brushing mechanism, an optical system for
measuring length and uniformity, and a clamping jaw system for measuring strength and elongation. It is
operated by placing a sample prepared using the Fibro sampler 192 in the comb track of the Fibro-graph
Plus where it is automatically brushed and moved into position for testing.

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The comb track is enclosed within the Length/Strength cover. To access it, lift the door located on top of
the brusher and place the fibro comb in the track. The Length/Strength start button is then pressed to
initiate the measuring process, or it can be automatically prompted using the software.
♦ The main power and blower switches are located on the Length/Strength Module plexiglass cover.
♦ The vacuum box has been replaced with a lint/waste box and blower system. The lint/waste box is
located behind the left door of the Length/Strength Module cabinet. The blower can be turned off when
not required for measurements.
♦ Two buttons, located on both sides of the Color/Trash mechanism, must be pressed simultaneously to
initiate the Color/Trash Test.
2 Micronaire Module
Micronaire is measured by relating air flow resistance to the specific surface of fibres. An air stream is
passed through a known mass of fibre confined in a chamber of fixed volume. The pressure differential
across the chamber is then related to the specific surface of the fibre to determine the micronaire value for
cotton.
Before a sample is placed in the micronaire chamber, it must be weighed. A precision electronic balance
is provided to weigh the sample and is protected by an acrylic guard (the optional bar code reader can be
attached to it). The testing chamber for micronaire measurements is located directly below the electronic
balance
2.2.2 USTER® TENSOJET 4
Working principle
The USTER® TENSOJET 4 is a tensile testing installation for the quality control in the textile
industry. It tests the real strength of textile staple fibre yarns. The determined values for the tensile force and
elongation allows to make a prognosis on the suitability of the tested yarn with regard to the behavior in the
future processing as well as on the quality of the end product.
Figure 2.1 HVI 900

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The digital tensile testing installation USTER® TENSOJET 4 determines the breaking force and the
corresponding elongation of textile yarns. Because of the high-resolution, digital scanning of the
force/elongation characteristics during a measurement, the computer is able to determine additional test values.
In addition to this, the force/elongation characteristics can be recorded as a graphic display. The measurement
of the tensile force in the yarn is achieved indirectly by a force sensor.
Force diagram
A Test material F Normal force
B Drafting rollers FT Tensile force in the test material
C Force sensor FM Measured force
A Test-Unit casing
B Suction nozzle C Force sensor
D Disk drives
E Yarn cutter
F Key block
G Yarn changer
H Yarn clamp
I Cutting device
J Pair of transportation rollers
K Yarn storage unit
Constant rate of elongation (CRE) testers
In order to standardise the conditions of the test, it is desirable to load or extend the specimen at a
constant rate through out the test. However, though this looks simple and straightforward, there is a
complicated interaction between the extension of the specimen and the movement of the load-measuring or
load-controlling system. Some methods also give rise to inertia or other errors.
L Pair of control rollers
M Laying-in arm
N Feed-in jet
O Pair of upper drafting rollers
P Cover of the measuring channel
Q Pair of lower drafting rollers
Figure 2.3 Tensiojet parts
Figure 2.2 Tensiojet working Principle

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2.2.3 USTER® AFIS PRO (Advanced Fibre Information System)
Working Principle
Uster Afis measures fibre length and maturity in raw cotton, card mat and sliver. The length is measured on
single fibresin order to get a true fibre length distribution within a cotton sample. The AFIS PRO is
the only instrument that measures the maturity of single fibres, resulting in a true distribution of maturity within
a cotton sample.
The AFIS measures every single fibre in a cotton sample. Three-thousand fibresare counted in each sample,
resulting in a true fibre length distribution by number. The following parameters are reported on the AFIS:
Most spinning mills today use the USTER® AFIS PRO to control the opening and cleaning line, the cards and
combers in their plants on a regular basis. Draw frame slivers are tested less regularly, and roving only in cases
where a change in the machine settings requires it. However, there is generally no direct influence on the fibre
material possible after combing in the spinning process. For regular quality control purposes, it is sufficient to
test material until comber sliver, only.
Fibre Fineness [mtex] is determined optically on the AFIS PRO by analyzing the fibre shape passing
the sensors. Originally, fibre fineness [mtex] is determined gravimetrically by cutting and weighing the sample
[3]. An algorithm determines fibre fineness based on the shape and form of the fibres. As mentioned before,
mature fibresdo contain more cellulose than immature fibres. Thus, mature fibresare also heavier fibresthan
immature fibres. This results in a higher fineness value for mature fibre since mtex. Fibresthat are less mature,
containing less cellulose, therefore result in a lower fineness value.
The purpose of opening and cleaning in the spinning mill is, as the name says, opening the cotton and
cleaning the trash out. Further cleaning can be achieved at the cards. Most modern machinery today also
includes suction systems to reduce the dust emission in downstream processes, for example at the draw frames.
Ayka uses the USTER® AFIS PRO to control the opening and cleaning line, the cards and combers in their
plants on a regular basis. Draw frame slivers are tested less regularly, and roving only in cases where a change in
the machine settings requires it. However, there is generally no direct influence on the fibre material possible
after combing in the spinning process. For regular quality control purposes, it is sufficient to test material until
comber sliver.
2.2.4 Uster 4
Working Principle
The digital USTER® TESTER 4 installation with its capacitive sensor determines the mass variation in
rovings and slivers, staple fibre yarns and filament yarns. Optional optical sensors allow the measurement of
evenness, hairiness, surface structure and impurities in staple fibre yarns. Additional systems for gravimetric
determination of material count can also be connected to the installation.
With the combination of the TEST-UNIT and the integrated computer in the CONTROLUNIT, the system is
capable of providing detailed information on the tested material and presents the test results in numerical and
graphical form.

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The USTER 4 displays results a combination of graphics which represents test values and a simultaneous
colour-coded classification and assessment of the quality data, which are extremely easy to read and
interpret.Most of the time Ayka lab uses this machine to measure CV% variation.
Using Uster 4 uses two types of sensors:-
 SENSOR CS
Function: Measuring unit for the determination of mass variations in yarns, rovings and slivers of staple fibres
• Measurement range: Approx. 1 Tex to 12 ktex
• Measurement technology: capacitive measuring unit
 SENSOR OH
• Function: Measuring unit for the determination of the
hairiness of staple fibre yarns (simultaneous with the
determination of mass variation)
• Measurement range: Approx. 5 tex to 1000 but tex
limitations according to the type of fibre are possible
• Measurement technology: optical measuring unit
2.3 Colour Calibration (Uster® colorimeter 750)
Color identification is one of the necessary requirements to identify the quality of a raw material and for
materials in blow room. The standard reflective index (Rd) and brightness (+b) values are fixed using a Ceramic
tile which has two sides of brown and white (Fig 2.5 B) as a standard. The tiles are observed in the order
requested on the machine. We first calibrate the White tile and then the Brown one. During this procedure, the
tile being measured is compared to the standard value stored for that tile in the memory unit of the colorimeter
machine (Fig 2.5 A). If the values are different, the system adjusts the constants. This could cause measurements
to be skewed is the incorrect tile is tested. The standard values are shown in the table below.
After the machine is properly calibrated ten samples are taken, for example form bales with same lot number,
(refer to raw material) then they are put on the screen found at the top of the machine so that no light penetrate
through the sample to be tasted. The values of Rb and +B appear at the control panel automatically. This value
Tile color Rb value +b
Brown 58.1 11.9
White 79.1 4.4
UT4-SE/M
1 Control unit
2 Test Unit
3 Screen, Keyboard, Mouse
4 Printer
5 Package carrier
Figure 2.4 Uster® 4 main parts
Table 2.1 Colour calibration tiles types

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is compared from a list of values. For a given colour range (21-1, 31-1, and 41-1) is termed as white colored
cotton and spotted cotton has (12-1, 31-2, and 41-2) values.
2.4 Quality Monitoring
As row material is delivered the lab performs many tests using the above lab machines. Each machine is
used to measure particular property of the sample under standard atmosphere for textile testing which is
temperature of 20±2 °C (68±4 °F) and 65±2%.
Uster Afis measurements are Finesse, Nep size and contents, maturity, dust and trash contents,
Uster HVI 900 measurements include Micronaire value (Finesse), length, strength and uniformity.
Uster Tensiojet measurements are elongation under tension and other physical properties.
Results are compared between practical measurements and the data provided in the USTER® STATISTICS
table. The USTER® STATISTICS for are established by collecting quality and productivity data online with the
data system USTER® SLIVERDATA in the spinning preparation of short-staple spinning mills. The data are
procured on a global scale via agents, international partners or direct contact with customers and are based on
the measurement results of a total of 550 deliveries of sliver producing machines collected by USTER®
SLIVERDATA customers from every part of the world. The USTER® STATISTICS for samples consists of
several parts, each addressing a specific quality or productivity aspect in the production sequence of fibres or
slivers in the short-staple spinning mill. The different sections are arranged according to the material
composition. Each section is subdivided into distinct quality or productivity characteristics (e.g. mass variation,
production per hour, etc.) which were recorded with USTER® SLIVERDATA. A measurement can consist of
several individual parameters. Mass variation, for instance, includes CV% andCV100m%. These parameters are
presented in graphic form. A register is provided for quick reference to the sections of interest.
If the results are compatible with the Uster values provided then that sample will pass. If not after some
more tests it will be rejected and necessary measures like adjustments of machine setting or change in
conditioning or any other measures are taken.
Figure 2.5 A) Uster® colorimeter 750 machine B) Standard tile

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2.5 Problems and Recommendations in lab
 The objective of maintaining standard atmosphere in the testing laboratory is to ensure that the test
specimens are conditioned to the standard atmosphere either by evaporation of excess moisture presents
within them or by absorption of moisture from the atmosphere into the specimen to the standard regain
levels. Invariably, the conditioning process takes about 24 hours – more or less – depending on the ability of
the test specimens to absorb or to desorb. Well-opened out specimens will condition quickly whereas highly
compressed specimens take inordinately long time. Cotton as a hygroscopic fibre absorbs moisture and
becomes stronger with it. The time it remains in a conditioned or unconditioned area determines how much
moisture will be retained.
 The other thing that must be improved is the mode of transport of the specimen from the corresponding
machines. As the air is full of flies and different temperatures from blow room to winding, the specimen to be
tested must be transported to the lab with in an insulated medium. The location of the lab in Ayka is in front
of the ring frame. Though temperature and moisture in the air is adjusted to the appropriate value in each
department, specimen form card from section 2, i.e. the section which produces black (dyed) and blend
products, the relative humidity is more and the temperature is less in that section, so if a card sliver is exposed
to the conditions in section one, i.e., white cotton processing department with higher temperature and
humidity, the sample will be conditioned to the first section air condition and not the true condition. So it will
result in wrong figures in testing the specimen since the testing methods in much of the lab instruments is
capacitance and optical methods. Not only the material is contaminated by section 1 flies form white product
which influence the optical measurement, the moisture content will change making it less resistive to electric
current making the instrumentation inaccurate to a significant value.
When samples are brought into the testing room, it is important to know whether the humidity in that
room from which they brought is higher or lower than that in the testing room. If the humidity in the room
from which the samples were brought is lower than that of the testing room, then even after a long
acclimatization time, the room will attain lower moisture content than if the yarn had been brought from a
room with a higher humidity. For instance for a room of 65% humid, the moisture content will approach
approximately 6.8% if the yarn is coming from a room with lower humidity and approximately 7.8% if coming
from a room with higher humidity. Here moisture content of yarns is referring to this value with respect of
the yarn mass. Therefore, with a cotton bobbin of 7000 m of yarn, with 25 tex (Nm 24), a moisture content of
6.8% is referring to the complete yarn mass on bobbin is 179gm, of which 11.9g is water.
Therefore, it is of utmost importance to operate in a controlled laboratory environment, if a laboratory wants
to obtain repeatable results.

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3. BLOW ROOM
3.1 Introduction
In the conversion of baled cotton into finished yarn, the primary purpose of the preparatory processes
is to open, clean, and parallelize the fibres and then present the material for spinning. In doing so, these
processes convert a three-dimensional bale of compressed, entangled, matted fibre mass into an orderly
arrangement of fibres in a one-dimensional continuous strand length. The objective is for the conversion to be
achieved with minimal fibre breakage and no fibre entanglement remaining in the strand length. A great deal of
attention has been paid to, among other factors, improving machine setting and the operating speeds of
component parts so as to attain gentle working of fibres and to avoid fibre breakage. In order to do that a
number of different machines are situated for conversion of the bale form to the appropriate package to be
transported to the carding machines. These machines are collectively known as blow room machines and the
place is called blow room.
Generally the functions of blow room include
I. Opening and cleaning
Dirt can be practically removed only from surfaces.
New surfaces must be created continuously in blow room for continuous cleaning to be
achieved. That is why Ayka has many machines with different setting but basically has rotating
beater that are used for creating new surface.
The ‗form‘ (the size, the gap between the beaters and so on) of opening machine must be
adapted (suitable) to the degree of opening already achieved. The opening devices must become
continuously finer; within a blow-room line, a specific machine is required at each position.
The degree of cleaning is linearly dependent upon the degree of opening.
Newly exposed surfaces should be as far as possible cleaned immediately (cleaning should
immediately proceed opening).
A high degree of opening in blow-room facilitates prevents or reduces fibre damage (reduction
in staple length) for better cleaning in carding.
II. Disentangling and further cleaning
III. Fibre straightening and parallelizing (with short fibre removal and additional cleaning)
IV. Flock Blending and Mixing.
Blending involves combining different row materials to achieve end use requirements
Automatic bale opening machines do the job much more satisfactorily (with control systems – to
extract exact quantities from each type of bale/blend/fibre). Weighing hoppers also do a satisfactory job.
Blending machines; mixers do a similar job; where blending can be controlled more satisfactory (as found in
blending machines.

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Figure 3.1 Automatic Uniflock machine
Objectives of blending
1. To give the required characteristic to the end product (e.g., MMF + Natural fibres – to give advantages
of both MMF and natural fibres)
2. Compensate variation present in one variety (of, say, cotton)
3. Reduce overall cost
4. Improve processing conditions
5. Obtain effects – by mixing different colors, other characteristics and so on.
Mixing- involves combining similar row material to produce a single property of cotton. Its main purpose is
to activate basic product uniformity that results from the combination of variability of row materials each
exhibiting different degrees of variability.
In Ayka, the blow room is divided in two sections. The first section is used to process row cotton or
man made fibres like viscose and the second section is used to process dyed cotton which comes form
dyeing department. There is a separate room within the first section to process polyester.
This division of sections is necessary to avoid contamination of each row material. Also the second section
is used for blend products like Grimilage and Antras which vary by the amount of blackness. The Grimilage is
darker and has 52% black cotton blend and Antras which is slightly lighter has 42% black cotton blend.
Though the sections are separated the same machineries work in both parts. The general air condition for
Ayka blow room is 29.2 to 32 degree centigrade and relative humidity 44.6%.
Below is explanation of each machine in the blow room.
3.2 Blow room machines in Ayka
3.2.1 ROBOT or UNIFLOCK ( Reiter model A10 Herman machine)
The initial opening of bales of virgin cotton and short-staple man-made fibresis commonly performed by
machines called automatic bale openers . Figure 3.1 depicts a typical arrangement. As shown, rotating opening
rollers fitted with toothed discs are made to traverse a line of preassembled cotton bales, the toothed discs
plucking tufts from each bale as they move from bale to bale. The arrows show the path of tufts transported by
airflow.
The robot can accommodate 160 bales at once. It is used
1. control unit
2.bale
3. working head with
toothed disks
4.swivel tower
5.air duct for material
transport

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for picking a predetermined amount of tuft from each bale. It has sensors underneath #3 to identify the
presence and height of bale remaining so that can adjust its head to the required height. The head can also rotate
manually 180 degrees so that 80 bales can be put on each side of the head.
It moves fallowing its rail #6 to pick from each bale. There is a motor underneath which moves the belt that
moves the body of the robot. The tuft moves through #3 and enters a tube which runs through the length of
the robot. The tuft moves inside the hallow rail to the argema machine. To do this the tube moves with the
belt. In other words as the robot moves the tube and the belt are in contact so that direct and continuous
transportation from head to rail takes place.
The control panel #1 controls the overall performance of the machine. It controls its speed, operation,
conversion of signals form sensors to appropriate action for the head or any other part of machine. It is also
used as an interface so that any error can be identified easily or for the orator to take action.
3.2.2 CAGE CONDENSOR (Reiter model)
To remove dust particles in transporting airflow, a perforated surface may be used to separate the tufts
from the dust-laden air. Figure 3.2 illustrates the use of a rotating perforated drum, often referred to as a
condenser drum, cage condenser, or dust cage. The airflow in which the tufts are conveyed is generated by a fan
connected by ducting to the interior of the cage. As shown, the tufts are pulled onto the outer surface of the
drum, the holes being sufficiently small to prevent fibre loss, while the dust-laden air flows through the holes of
the drum for the dust to be collected as waste. To remove the tufts attached to the slowly rotating drum, the
suction is blanked off by a half-cylinder screen, which is positioned where the tufts are required to leave the
drum. Condenser drums are positioned at the inlet to a hopper either before or after an opening stage.
It is used to transport the material by air (pneumatically) due to induced along the line of the cage condenser
by the rotation of motor fun. Its perforated drum is used for the separation of air and material. The purpose of
separation air from the material is to prevent the damage caused by high concentration of air. High
concentration of air may explode the machine if it is removed. And it is found at the top of most machines in
the blow room.
3.2.3 Uniclean (Reiter model B11)
The Uniclean single-beater system takes advantage of the small tuft size that can be produced by automatic
bale openers. The pin projections from the beater surface are smaller and greater in number, and the objective is
to make contact with all tufts. It can remove the heavy impurities of sand, dirt, and fine trash, working on small
tufts enables the removal of dust particles.
Figure 3.2 cage
condenser

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Figure 3.3 Diagram of cage condenser
1) Single beater (2) flexible pin projections and grid bars (3) trash removal paddle.
With these systems, curved plates are fitted above the beaters to
control the number of spiral passes usually a minimum of three times. The
tufts are accelerated, decelerated, and turned over during each pass. The
angle of the grid bars and the space between them can be adjusted so as to
optimize the amount of impurities removed and to minimize any removal
of fibre. The beater speed range is 400–800 rpm, with a diameter of 750
mm and a working width of 1.6 m; production rates are up to 1200 kg/h.
Importantly, trash particles present in the tufts are not crushed. This would
increase the number of fine particles, thereby reducing the effectiveness of
the system and making subsequent cleaning more difficult.
3.2.4 Blending feeder (Reiter model B34)
Blending feeder is used to obtain even blending of materials of the same quality or different qualities. The
machine can be used single in case of reduced production, or in group. Its aim is to mix clean and open the row
material.
Feeding is always by lattice. At delivery the material falls on conveyor belt, in case of group machine; the
material is pneumatically sucked, in case of single machine. In Ayka there are 4 blending feeders 2 for
processing white cotton and 2 for dyed cotton. So there is a pneumatic system of transport the material due to
induced air by the cage condensers.
Generally we can do about five points of action
1 initial manual treatment action
2 mixing action in blending box or hopper
3 tearing action with spikes of inclined and evener lattice
4 detaching action of detaching roller
5. Beating action of porcupine beater against the sharp edge of grid bars
Operation sequence of blending feederFigure 3.4 Blending feeder

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The material reaches the blending box by means of an inlet lattice with electromagnetic cutch drive.
Feeding is controlled by screen, at the blending box inlet, which signals the lack of material lightning a lamp on
control panel. In the blending box the material falls on bottom lattice, which transports the tuft towards the
incline lattice.
A stock control screen stops the feeding from the inlet lattice when the blending box has excess of
material and restarts the feeding in the opposite cases. The material is then lifted by the inlet lattice, towards the
adjustable evener lattice, which operates opposite to the inclined lattice and therefore proportions (the material
to be forward) and opens the material. Dust removal from the blending box is made by an exhaust fan
positioned in the upper part of machine and connected to the machine drive motor.
The material is detached from inclined lattice by detaching roller, it is cleaned by a grid bar, conveyed by a
couple of conveying rollers, nipped by the pressure rollers and reaches the porcupine beater, which is the
second opening point in blowing line. Cleaning is completed by an adjustable blade grid, under the porcupine
beater, and the material is then delivered to the next machine through pneumatic system.
3.2.5 Auto-mixer (Reiter model B )
Automixer has been designed to obtain even blending from cotton and chemical fibres of different
qualities. These blending/ mixings have different density in each cell with decreasing value from the first to the
last coil.
The machine has a frame with steel coverings as required by the safety regulations. The motors and the
electrical derives are synchronized and in sequence with the centralized control panel. The main components of
the machine are the feeding unit and the delivery unit.
Feeding unit
1) Horizontal cage condenser with detaching roller
2) Upper lattice for the progressive feeding of the cells (which lattice deriving rollers (#3 and lattice
supporting rollers #4)
3) Blending cells (6-8-10) with a capacity of 50-100kgs each, according to the type and density of material.
4) one photocell with only one fed blend
5) Upper photocell to stop the feeding when the material reaches the maximum level in the last cell
6) Lower photocell to signal the minimum level of the material in the last cell
i. A2 Photocell with feeding a double blend
7) 6A upper photocell is used to stop feeding the material reaches maximum level in last cell
8) delivery unit
9) two conveying rollers per cell
10) one opening roller per cell
11) lower lattice to convey the material outside
12) safety photocell at the delivery, it stops in case of material clogging on the lower lattice
13) collecting box for waste
The operation of Automixer is divided into two phases: the initial feeding and the operation cycle.
A. First phase: initial feeding

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The discharge components of the machine are still, the feeding ones get started. The material is sucked by
the cage condenser and the upper lattices starts to progressively fill the cells. During this operation, some
material is still let into the cells already filled and therefore it determines in each cell different densities with a
decreasing value from the first cell to the last one. The cell filling is completed when the material in the last cell
or last but one if we work with double blend, reaches the maximum level mark. The whole operation is
controlled by the control panel.
Second phase: operation cycle
At this point the discharge components get stated. Under the action of the conveying rollers and opening
rollers, the material contented in the cells gradually deposits on the lower lattice and is conveyed outside
The operation starts the feeding of the machines after the Automixer acting on the drives of the centralized
control panel. In this initial discharge phase the material in the last cell goes under maximum level mark. The
photocell calls and varies the feeding without cycle of feeding and discharges with balanced compensation
between discharged material and material fed in each cell.
All theses operations are synchronized and in sequence with the centralized control panel. If for any reason
the material discharge is more than the feeding, the material in the last cell goes under the minimum level mark.
The lower photocell signals to the control panel to signal the operator that the automioxer is under the limits.
3.2.6 Horizontal opener (UNIFLEX MACHINE, Reiter model B60)
Horizontal opener is another machine for further opening of tuft with single beating roller. Its beater is
covered with metallic sow toothed neddles and it rotates eith a speed upto 450rpm. Waste material removal is
assisted with grids situated beneath the rotating roller. As the roller rotates it holds long fibre on its wires while
short fibresand any heavey material is removed throu the gaps in the grids. Also due to the beating action of the
rotating roller with the grid bars heavy material is removed while centrifugal force assists the adhesion of fibrs
to the wall of the roller. And due to suction mehcanism at he top of the machine the fibresare sucked and
removed from the roller and be ready to be transported penumatically. There is another suction mehcanism to
clear the waste form the grid and roller to be transported to waste room.
The feed screen has two photosensors positiond at the top and bottom of the transparent screen. The top
sensor detecs the maximum amount of tuft. There is an light emitter and light sensetive screen positioned parrel
Figure 3.5 Auto mixer

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to it. As there is a material in between the emitter and reciver the light form imitter cant reach the reciver. So by
relaing this information to the control pannel feeding to the machine automatically stopes until the material in
the screen is processed by closing a valve positioned at the top of the machine where feed matrial inters. The
bottom phtosensor works in the same way as the top but hre it sences lack of material so it sends message to
open the valve.
The transparent screen is adjustabel so that the volume of material accomodated insied it can be adjusted.
3.2.7 UNIBLEND MACHINE( REITER MODEL B78)
This is a basic machine for blending and mixing process. Its most important feature is that it can control
blending with the predetermined amount fed to its control system. It can process both cotton-cotton blends
and Cotton-polyester blends. As stated in the above pages Grimilage and Antras products are produced by
adjusting the amount of white cotton with the black one. Grimilage is 75:25 black white ratios while Antras is
60:40 blends. Uniblend has colour detecting sensors which work with the two valves used to insert material to
the machine. It has a microprocessor which analyzes this data and controls the ratio.
In addition to the above machineries there are also valves, which control the direction of material flow so
that it can move to the required machine, bypass valves which are used to direct material so that there will not
be any collision and it just pass through, fire sensors and automatic extinguishers, fans as a source pressurized
air for the pneumatic system of transport, an underground suction system which runs all over the spinning
department for suction of flies. There is also heavy metal separator (HMS) which separates metallic materials
form the textile material using magnet. This, if not removed would cause fire hazards due to friction and it
might also damage sensitive parts of a machine like gear teeth. So it is necessary to remove it as early as possible.
There are different duct works to transport different kind of materials and they can be identified by there
colour. This are yellow pipes for clean material transport, Blue pipes for waste transport and Red/Orange pipes
are connected to the fire extinguisher when ever there is a risk of flame in the pipes. Comber waste is recycled
and is combined to dyed cotton to make blended yarn. Blow room waste is repressed again in waste processing room and
sold to local markets for making mattes. Ring, Roving and winding wastes are also sold. The cost of wastes can reach up
to 50 birr per killo.
Figure 3.5 Horizontal Opener with location of sensors left

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Legend
Uniflock Uniclean
Uniflex HMS
Uniblend valve
Card By pass
Automixer Fan
Blending Feeder
Blending Feeder
Blending Feeder
Table 3.6 Block Diagram of Blow room

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3.3Problems observed in Blow ROOM
1) There is a considerable amount of downtime of blow room machines, i.e. most of the machines are not
working, thus decreasing the productivity of the room. In most cases the reason has been the wrong
synchronization of productivity of the machines with the next machines in the flow of materials. The
productivity of the blow room is mostly higher than the subsequent machines causing interruption of material
flow. This causes unnecessary storage of bales in blow room. This has a devastating effect in the quality of final
product. The bale is exposed to the high humidity and temperature of the blow room and due to the
hygroscopic nature of cotton, moisture is abnormally accumulated and causes inaccurate reading in lab testing
(refer to lab) and roller slippage during drafting.
2) There is unnecessary storage of unusable bales at the corners of the room. This not only occupies space it
also causes additional flies i.e., short breathable fibresin the air, and dust in the room, it adds up to the ambient
heat of the room.
3) The other problem is lack of Hygienic Aspect of Ventilation. Exposure by inhalation of dust is a major
cause of occupational illness and disease. Pneumoconiosis, which is a lung disease caused by inhalation of dust
and flies which after time will block the tiny air holes in the lung. Any excessive temperature makes it difficult
for the physiological mechanisms of thermoregulation to function effectively and, consequently, leads to a
feeling of discomfort by the workers and lowers their productivity. The workers have no protecting mask to
avoid inhalation of dust and flies and for protecting there eyes.
3.4 Recommendations
We can divide the first problem into two parts. The first is how to solve the problem stoppage of machines.
This can be solved by
1. Doing proper preventive maintenance work on time.
Blow room machines are very huge and defects might happen on any part of the machines. This
means we should have a schedule to inspect the machineries on time. This regular inspection will help
us identify problems before they cause major problem like machine stoppage and inclination of quality
of product. So using a time table which will help to regularly inspect all machines is necessary. Minor
maintenance work like cleaning, screwing, checking electrical components should be done after
inspection. A weekly Inspection and Minor Maintenance table for Blow room machines is
recommended on table 3.1.

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Mc type Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Uniflock M I I I I I I
Uniblend I M I I I I I
Uniflex I I M I I I I
Uniclean I I I M I I I
Automixer I I I I M I I
Blending
feeder
I I I I I M I
HMS I I I M I I I
Valves I I I I I M I
2. Proper synchronization of Blow room productivity with subsequent machines, i.e., Card machine.
Different kinds of methods have been used to adjust the productivity of machines in Ayka. The main method
was completely stopping the machines. This measure should only be used when there is no material needed
form that machine or when ever there is major maintenance taking place. Because if the machines are stopped
when ever they are not needed, some problems with irreversible effects occur. As said before blow room
machines are huge with heavy moving parts with very small tolerance. During stoppage of machine for long
time, because of the weight of components, metallic parts start to stick together and a phenomenon called Local
welding takes place. This means because of weight and surface to surface contact the outer surfaces of metals
tend to stick together the blow room has high temperature and humidity accelerates this effect. In order to start
the machine we need more to overcome static friction costing more power, breaking sensitive parts like gear
teeth. End breakage costs more than the power intake of the machine if it worked with less efficiency.
So instead of stopping the machine every now and then it is better to use less efficiency for operation. This
method helps to give time for other machines to cope up with its production. And also the above problems are
minimized. This can be done by carefully monitoring the material stock in store room so that if a particular
stock is becoming less, we should use the above method until shortage of stock is solved.
3. The other problem is the air ventilation system which only focuses to the row material and not the
operators. It can be said that blow room is the toughest environment to adapt than any other department in
textile mill. Its high humidity and temperature makes it hard to adapt and work properly.
Ventilation and air condition is the process of treating air so as to control simultaneously its temperature,
humidity, cleanliness and distribution to meet the requirement of the conditioned space. Comfort depends
partly on humidity, and air conditioning removes moisture from the air or adds it as needed. Removing dirt and
dust from air makes the air more healthful. By controlling air movement, air conditioning brings fresh air into a
Table 3.1 Weekly Inspection and Minor Maintenance table for Blow room
machines I – Inspection M – Minor maintenance

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room and pushes out stale air. In all these ways, air conditioning provides air that makes people comfortable at
work
Any excessive temperature makes it difficult for the physiological mechanisms of thermoregulation to
function effectively and, consequently, leads to a feeling of discomfort by the workers and lowers their
productivity. Besides high temperature, many of the production processes in textile mills are accompanied by
the liberation of considerable amounts of water vapor (sizing, bleaching, dyeing, wet spinning, etc. ). High
humidity usually occurs together with a high temperature. Under such conditions the human thermoregulation
mechanism is placed under extreme stress because at temperature close to that of the body the heat loss through
convection and radiation becomes very small, while the high humidity of the air hinders effective evaporation of
moisture from the surface of the skin. Therefore, the combination of high temperature with high humidity in
the room atmosphere produces a condition very unfavorable for the comfort of human beings.
Ayka Spinning department uses Central station type plant. In this type, there are two separate units. The
main plant consisting of fan, air washer and other accessories is located in a plant room which is outside the
conditioned space. The fan, air washer and circulating pump are all at floor level in a separate room. Only the
air distribution system is in the conditioned space. The air-circulating duct is in the conditioned space, usually
near the ceiling and often between the roof and the ceiling. Diffusers are provided in the duct at suitable spacing
to distribute the cool humidified air but they are not positioned evenly as possible in the conditioned space. So
that suspended particles are found all over the room. If there are more ducts around the blending feeder area
and the Automixer which produce more flies, the suspended particles will be reduced. We can adjust the
efficiency of underground suction system, i.e. increasing it, so that more flies can be sucked. We can also extend
additional ducts form the ceiling so that cool air will reach the operator.

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4. CARD or Tarak machine (Reiter model C7)
4.1 Introduction
Carding is the action of reducing tufts of entangled fibres into a filmy web of individual fibres by
working the tufts between closely spaced surfaces clothed with opposing sharp points. Machines used to carry out
this work are called cards.
One of the main functions of a card is to disentangle tufts of fibre into a web of individual fibres. In this
respect, important considerations are the process of fibre individualization, the formation of the doffer web, the
fibre extent and configuration.
I Opening to individual fibres - Whereas the blow room only opens the raw material to flocks, the card
must open to the stage of individual fibres. This is essential to enable elimination of impur8ities and
performance of the other operations.
II Elimination of impurities - Elimination of foreign matter occurs mainly in the region of the taker - in.
Only a small part of the contaminants is carried along with the flat stripping, or falls out at other positions. The
degree of cleaning achieved by the modern card is very high, in the range of 80 to 95%. Thus, the overall degree
of cleaning achieved by the blow room and the carking room together is as high as 95 - 99%. Card sliver still
contains 0.05 - .03% foreign matter.
III Elimination of dust - In addition to free dust, which can be directly sucked away as in the blow room,
the card also removes a large proportion of the micro particles that are bound to the fibres. Significant fibre/
metal or fibre/ fibre friction is needed in order top loosen such particles. Both are available at the card in
considerable measure: the card is a good dust-removing machine.
IV Disentangling of neps - While the number of neps increases from machine it machine in the blow
room, the card reduces the remaining number to a small fraction. It is often falsely assumed that neps are
eliminated at the card; in fact, they are mostly opened out. Only a fraction of the neps leave the machine
unopened via the flat stripping.
V Elimination of short fibres - Short fibres can only be eliminated if they are pressed into the clothing.
Since that is not possible with metallic clothing, only the flats can be considered in this context. The ability to
select short as opposed to long fibres is based in the fact that ling fibres have more contact with the clothing of
the main cylinder than the short fibres. Thus longer fibres are continually caught and carried along by the main
cylinder. Short fibres, on the other hand, offer fewer surfaces to the clothing of the main cylinder; they therefore
stay caught in the flats clothing, press into it and leave the machine in the flat stripping.
VII Fibre orientation - The card ids often attributed the effect of parallelizing. This is not completely
justified, since the fibres in the web are not parallel, although they do have, for the first time, a degree of
longitudinal order. A parallel condition is achieved on the main cylinder, but it disappears during formation of
the web between the cylinder and the doffer. Thus, the card can be given the task of creation partial longitudinal
orientation of the fibres, but not that of creating parallelization.

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VIII Sliver formation - In order to be able to deposit the fibre material, to transport it and process it
further, an appropriate intermediate product must be formed. This sliver, in extreme cases, card sliver has a
hank of 3ktex (new spinning processes) or 6ktex. Generally the hank lies between 4 and 5.5 ktex in the short -
staple-spinning mill.
Ayka has 19 electronically controlled high performance short staple carding machine. The setting (gap)
between machine elements, delivery roller speed, and cylinder speed can be controlled using control panel. In
addition, technical data like machine stoppage reason, number of can change production per shift, actual
production per hour, actual efficiency of machine can directly be gathered from the control panel.
Mostly, Ayka works with around 99% efficiency of the machine with normal delivery speed of 120m/mins.
One delivery of sliver is 4500meters with an average weight of 20.5 kg with CV% variation ranging from 1.1 to
3.3. It takes about 50mins to fill one can with no stoppage of operation.
Material is fed to each card form Automixer of blow room pneumatically. Wastes from flat, cylinder and
rollers are removed by suction to waste processing room. Waste value is usually 15 -17% of its feed material.
Since the production rate of a single card cannot match the blow-room output, several cards must be used
and linked to the blow-room in such a way that there is a uniform feed of the fibre mass to each card. Ayka has
13 cards in the row cotton processing section and another 6 cards in the dyed cotton processing section. Here if
the product passes through the carding mechanism and not through comber the waste of that sample can reach
up to 35%
Figures 4.1 and 4.2 illustrate that the tufts are transported pneumatically to each card via distribution ducting.
Each card has a chute feed system connected to the ducting. There are various designs of chute feeds, but their
working principles are basically similar. There is an upper and lower chute separated by a feed roller and beater,
and a pair of feed rollers is positioned at the end of the lower chute. Each chute has air-escape holes and a
pressure sensor fitted to control a preset compacted volume of tufts in the chute. The upper chute receives tufts
from the distribution ducting, and the transporting air is exhausted through the air-escape holes. The feed roller
and beater remove the material at a slower rate, enabling incoming tufts to build up in this top chute. As the
tufts build up and cover the air-escape holes, the pressure sensor detects the associated increased air pressure in
the chute, and the tuft feed is closed off. As tufts build up in the top chute, the beater reduces the tuft size and
feeds the smaller tufts to the bottom chute. Here, the compaction of the tufts is by air pressure from a fan
C 7card
Figures 4.1 Overview of blow room to card machine

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E.G 2010/11
blower. The rate of removal of the compacted material by the pair of feed rollers is slower than tuft feed, and,
much as with the top chute, a pressure switch controls the feed by stopping and starting the upper feed roller.
The waste level of the card machine is predetermined by the production controlling department and it is
pre set to 5-7%. This can be achieved by feeding the data to the control panel of the card machine. The control
unit then adjusts the settings between machine components.
.
4.2 Operating Principle
The material (cotton, viscose staple fibre, polyester, or any blend of these fibres) to the card is supplied
through a pipe ducting into the feed chute of the card. A portion of the feed chute is transparent for inspection.
An evenly compressed batt is formed in the chute. The linear density of the batt ranges from about 500 to
900 ktex. Obviously, the width of the chute will be about the working width of the card for maximum feed.
The weight of the batt with the downward guidance of the transport rollers found at the entrance of the card
just below the chute feed, the batt is transported to the feed roller and feed plate.
The chute has pressure sensors o maintain the evenness of the material. If there is anything wrong and the
pressure is lower, the display unit displays ―feed weight too small‖ if there is no feed ―empty airofeed‖.
The feed arrangement or feeding device consists of a feed roller and feeder plate. This pushes the sheet of
fibres lowly into the operating region of the licker-in. the feeding device should maintain an optimum pressure
otherwise the above error message will be displayed and machine stops. This section is transparent for
inspection and maintenance.
The sheet of fibres which projects from the feed roller is combed through and opened to flocks by licker-
in. this operation is performed by sow tooth wires wound onto the licker in on its surface. The licker in runs at
very high speed up to 600rpm.
The flocks pass over mote knives and grid bars found under the licker in. In so doing the materials are
separated from large impurities.
FIGURE 4.2 Short-staple carding
FIGURE 4.3 Basic features of a short-staple chute
line

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Suction ducts carry away the waste generated. The cylinder is covered with sow tooth type wire with
density of about 400-1000 wire points per square inch. The cylinder has diameter about 50‖ and rotates at a
speed of 359 to 400 rpm.
The flat and carding bars have a width of about 1‖ extending over the width of the card. The upper surface
of the cylinder is covered with approximately 100 individual flats but it depends on the accuracy of the counting
since it is hard to count it while moving because it is hard to locate the flat u started counting on. The individual
flats are joined by a chin making an endless chain rotating at a slow speed. The surface facing the cylinder is also
covered with metallic covers.
The setting between the flat wires and the cylinder wires are very, very close. Perhaps it is the closest setting
in spinning machines. This is vey critical for carding action expected form wire points.
The flock of fibresfrom the licker-in are carried away by the wire points of the fast rotating cylinder. The
flocks penetrate into the flats and open up to individual fibresbetween the cylinder and the flats.
A stripping device (cleaning device) strips the embedded wastes (short fibresand impurities) from the
individual flats. The bottom portion of the cylinder is also covered by grids or cover plates.
After the carding operation is completed, the fibresare carried on the surface of the cylinder. The fibresare
loose (not held except the loose frictional contact) and lie parallel on the surface. However, at this stage, the
fibresdo not form a transportable intermediate product.
A doffer runs at a substantially slow speed slow speed. This collects the fibreslaying on the surface of the
cylinder into a web. The calendar roller compresses the sliver to some extent. The coiler deposits the sliver into
the can.
As the spinning department is divided into two parts, 13 card machines are located at section 1, i.e. white
cotton producing section and another 6 are located in section 2, i.e. section which processes blended, dyed and
Man made cotton (Viscose).
Coiling
mechanism
Cylinder under
casing
Figure 4.4 A) card machine overlay with position of the sensors (dots)
B) Inside parts of card machine

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4.3 Problems Observed
As carding machine is one of the most important machine in spinning it should be diagnosed regularly. One
of the problems observed is since card machines work non stop for almost all days of the week there is no
periodic maintenance done on them and only they are checked when ever low quality product is produced or
when the machine stops because of malfunctioning machine elements. This is not a good approach because the
machine elements are really expensive to purchase and since there is no educated personnel to do the
installation they also have to bring the personnel causing extra cost. Also if only checked when there is
deterioration of quality of product a lot of card sliver will be wasted.
4.4 Recommendations
The problem can be solved using a regular maintenance scheme like below for all card machines with in 3
weeks. The following table is recommended as a Maintenance plan for card machines of both sections.
Mc
no
W01
W02
W03
W04
W05
W06
W07
W08
W09
W10
W11
B12
B 13
B 14
B 15
B 16
B 17
B 18
B 19
WEEK 1
M Tu W T F S Su
M I I I I I I
I M I I I I I
I I M I I I I
I I I M I I I
I I I I M I I
I I I I I M I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
WEEK 2
M Tu W T F S Su
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
M I I I I I I
I M I I I I I
I I M I I I I
I I I M I I I
I I I I M I I
I I I I I M I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
WEEK 3
M Tu W T F S Su
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
I I I I I I I
M I I I I I I
I M I I I I I
I I M I I I I
I I I M I I I
I I I I M I I
I I I I I M I
I I I I I I M
A regular inspection (I) is necessary activity to avoid end breakage. This activity also includes routine
servicing including lubrication, adjustments, and cleaning. This includes replacement of damaged bolt,
mending and repairing protection devices. All this activities should be documented for proper maintenance
store keeping and for further use. Major maintenance (over haul) which includes complete dismantling of
machine and checking all machine settings and accuracy of measuring devices should be done for a machine
twice in a year. In the above table (W) shows card machines in section 1, and (B) indicates card machines in
section 2.
According to the plan a machine should be medium repaired (M) at least once a week, given the importance of
high productivity of Card machine; it is not economical to stop more than one machine in a day.
Table 4.1 Maintenance Plan for card machine
Mc
no

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5 Draw Frame (Jer Machine)
5.1 Introduction
Draw frame is a very critical machine in the spinning process. Its influence on quality, especially on
evenness is very big. If draw frame is not set properly, it will also result in drop in yarn strength and yarn
elongation at break. The faults in the sliver that come out of draw frame can not be corrected. It will pass into
the yarn.
Objectives of the Draw Frame
Improving material Evenness - Draw frame primarily improves medium term and especially long term
sliver evenness through doubling and drafting. The number of doublings lie in the range 6 to 8 and so is the
range of draft; as a result, the input and output material is almost same in terms of liner density. Drawing is
done in two stages; at breaker and at finisher draw frames. Therefore, two passages of drawing with eight ends
(sometime six) each time would produce a single sliver consisting of 64 strands. This helps in reducing
variations.
Parallelization; - To achieve an optimal value for the strength of yarn, fibres must be arranged parallel to each
other and along the axis of yarn. Draw frame fulfils this task by way of the drafting by rollers. The amount of
draft to be applied immediately after the card cannot be very high as fibre entanglement is very high and the
strand is thick. As such, draft has to be increased gradually.
Mixing and Blending; - Drawing is the final stage of quality improvement in a spinning plant before yarn is
spun. This is by providing the degree of compensation of raw material variation by blending. This result is
exploited in particular, in the production of blended yarns comprising cotton/synthetic or synthetic/synthetic
blends. At the draw frame, metering of the individual components can be carried out. As an example, to obtain
a 67: 33 blend, four slivers of one component and two of the other are fed to the draw frame. However, these
slivers must have the same linear density. In the case of differences in linear density, thin slivers will not be
gripped properly by the drafting rollers, and disastrous results will be seen due to a group of some fibres drafted
away by the front rollers giving very high irregularity and fibre clusters in the drafted strand.
Dust removal; - Draw frame is a machine where a very high degree of fibre/fibre friction takes place in
the drafting zone; this is ideal for separating dust. Ayka draw frames have appropriate suction removal systems;
more than 80% of the incoming dust can be extracted.

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5.2 Parts of Draw Frame
5.2.1 Creel
The creel helps feeding the material to the drafting region. It must be designed in such a way to: Prevent
false draft and Provide stop motion to stop the machine in case any one sliver is absent. The slivers from the
creel should enter drawing zone closely adjacent to each other, but not on top of each.
In order to avid false draft the Ayka draw frame machine creel is positively driven i.e. it gets motion
conveyed from the main motor and not rotated from friction between the sliver and the metal surface. It also
has a heptagonal shape to effectively carry and transport the sliver to the drafting system and also avoid slippage
at the same time. The top rollers move by a friction between the sliver and roller surface. There is sensor o
detect whether there is a sliver present or not in top rollers. It works by detecting where there is metal to metal
contact, between top and bottom rollers and if there is contact, the solenoid will send a signal to the central
processing unit and automatically stops the machine signalling the operator to take necessary measures. Each
feed has its own creel. Jer machine has 8 feeds it has 8 creels though operators use only 6 feeds.
5.2.2 Drafting arrangement
Drafting arrangement is the heart of a draw frame. The drafting arrangement is Simple, Stable design for
smooth running at high speeds, Flexible to handle different types of fibres, Able to control fibres properly to
produce a uniform sliver, Easy to adjust in all drafting arrangements. Ayka draw frames fulfil all this
requirements by the help of electronically controlled speed changer and which show real time status using
control panel.
A B
Fig 5.2 different kind of rollers
Fig 5.1 creel

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Fig 5.4 Delivery and coiling
Bottom rollers are made of steel and mounted in roller, ball bearings. They are positively driven. These
rollers have one of the following flutes. Spiral-fluting (A) rollers are used mostly. Top rollers can roll on spiral
fluted bottom rollers more evenly and with less jerking and therefore spiral fluted rollers are preferred for high
speed operation; also they are used on rollers receiving aprons. Moreover, any defects in a flute spread out
helically in the drafted material and in subsequent drafts get distributed uniformly along the length. That is why
the first two bottom rollers are spirally fluted. The second pair bottom rollers are horizontally fluted (B) since
there is less material flowing and more of parallel web of fibres is needed. The diameter of the bottom rollers is
50 mm. Top rollers are coated with synthetic rubber. The drafting system of the machine is 3 by 3, 4 top rollers
by 3 bottom rollers. There is a pressure bar between the third and forth rollers for better guidance of the fibres.
Any fibre presented to the nip of the front pair of rollers should be immediately accelerated by that pair of
rollers and no slippage should take place. Due to this reason, front roller should have a higher pressure.
However, too strong pressure increases the wear of elastic cover; more pressure is often applied with reduced
settings like rollers 3 and 4. As the settings become closer, it becomes necessary to increase the pressure due to
increase in drafting force; otherwise roller slippage will occur. Pressure on top rollers is applied by means of
Pneumatic pressure
5.3.3 Delivery and Coiling
Material coming out of the drawing frame does not have much
cohesion. As such, in high speed operation, drafted material is immediately
converged through a tube (1 in Fig D-3) and guided though the trumpet (2
in Fig D-3) into the calendar roller. The diameter of trumpet (d) depends
on the sliver linear density. Usually For synthetic fibres, bigger coiler tubes
are used. This will help to avoid coiler choking and kinks in the slivers
while coiling in the can. Condensing by calendar roller is necessary in order
to fill up the can with more material. While the sliver is deposited into the
can, both the can as well as the plate on the top, having a tube through
which the sliver travels, rotate; such rotation helps to deposit the sliver in the
1
1
2 3
4
Guiding and tensioning
area(outside drafting) Drafting area
1
1
2
1
Fig 5.3 drafting arrangement

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form of a cyclonical coil. The tube extends from the centre of the plate to the periphery. The circumferential
velocity of the deposition point is somewhat higher than the delivery speed, so that blockage of the sliver is
avoided.
However, difference should not be very high; as otherwise, it may lead to false draft. Coiling can be under
centre or over centre. In most of the modern machines, full cans are changed automatically with empty cans. In
some automatic can changing mechanisms, the cans are replaced when machine runs at full speed and in some
others; the machine is stopped during the changing of cans.
5.3 Operating Principle
There are two passages for the jer machine in the spinning mill. These are the barker draw frame which is
a set 2 of draw frame machines before combing machine and the finisher draw frame which includes also 2 draw
frame machines located after combing in section one of spinning machines. In section two since there are no
combing machines barker draw frame comes after card machine and processes dyed cotton with combed sliver
from section one is used for blending procedure.
Most of the improvement in fibre parallelization and reduction in hooks takes place at the first draw
frame passage than at the second passage. First draw frame passage will reduce the periodic variation due to
piecing. Therefore the life of servomotor will be more and quality of the sliver will also be good because of less
and stable variations. Material flow in both passages is identical inside the machine.
For combed material with four doubling is used, it is better to use two draw frame passages in order to
reduce long thick places in the yarn.
Card sliver (3) in can (1) form is a direct feed for breaker draw frame in both sections. The sliver is then
carried by a creel (2) and then by a series of guiding and tensioning rollers (4) to the drafting system. This 3 by 4
drafting system (6) attenuates and drafts the sliver to a value of 7.5 for cotton and 7.9 for polyester. Combed
sliver needs more draft ranging up to a total draft of 7.5 to 8 is used. A suction system (5) is used to clean the
drafting system and then store the waste in storage compartment in the machine. Then the drafted sliver goes to
the coiling arrangement (7) for easy transport. Coiler size is selected depending on the type of material processed.
For synthetic fibres bigger coiler tubes are used to avoid coiler chocking and kinks in the slivers due to coiling in
the can (10). There is a can changing mechanism (8) so that empty can (9) replace the full one by itself. The cans
have wheels to help the automation. The entire machine is powered by a motor located at the middle of the
machine (11).

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As mentioned above both passages have the same machines with slight difference. The finisher draw frame
has a servomotor which is used for precise control of main motor and an Open loop type Autoleveler control
system. When ever there is a problem in sliver weight, more than the preset tolerance, it stops the machine. A
measuring sensor is provided in the region of the in-feed for continuous detection of the actual value of sliver
weight. A control unit compares the result with the set reference value and amplifies the difference signal and
feed it to an adjusting device which finally converts the impulse to mechanical adjustment. The regulator
provides a variable speed either to the back or the front rollers to give the required draft when the measured
material reaches the point at which the draft is applied. This is seen on the machine control panel as below.
If there is an imbalance the lights (circles) flash signifying the machine trying to adjust. The numbers signify
the maximum and minimum extent of deflection from the intended value.
8
7
6
1
4
1
3
3
1
2
1
1
1
11
10
9
1
5
1
Fig 5.5 overlay of draw frame with sensor
positions (dots)
0
1
-23 +23
Fig 5.6 Autolevelling

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5.4 Problems Observed and Recommendations
Roller lapping has been the major problem at draw frame. Because of constant lapping the machines were
forced to stop for a considerable hours which result in declining productivity since draw frame is a bottle neck
machine.
 Roller lapping can be a result of excess moisture content of the fibre or improper setting of rollers in the
machine. Row material store room has a significant effect on the moisture content of the fibre. Since Ayka
spinning department has its own storing department which has no air conditioning system, it is obvious the
effect will be on the material stored in it.
The Second and Third months of Ethiopian year, i.e. ―Tikimt and Hidar‖, are noted for there high
moisture and very cold weather in the morning and in the evening. The cold condition will condense moisture
around the cotton bale. Since cotton bale is stored open to the environment for accumulitization process,
moisture will stick on the surface of the fibres on the bale. And at Ayka Spinning Store, since there is no air
conditioning system, in order to adjust the room temperature the door is always open and this escalades the
problem.
This problem can be solved easily by installing air conditioning system, with Unit type plant. In this type
of plant, the circulating fan, humidifier and air distribution duct together with the heating coils are all
assembled as one unit and located in the department itself. The plant is usually hung from the ceiling.
Dampers are provided to make it possible either to draw fresh air from outside or to recalculate the inside air.
This is ideal as it is hung from the ceiling no floor space is lost, it will not interfere with space utilization of the
store room. And it is cheaper.
 In the spinning, it is better to use short setting between back and middle drafting rollers for better fibre
guidance, and widen the setting between top and bottom rollers by decreasing the top roller pressure. This will
minimize the complaints and improve the basic yarn quality.
 The suction system in drafting system helps to remove dust laden air. It also tries to suck any of the fibres
that tend to wrap around the rollers and thus helps in preventing roller lapping. The air is passed via a tube
directly into the exhaust system of the factory's air conditioning system or to filters within the machine. So it
is necessary to check the suction system for the drafting arrangement.
 Adjusting the moisture content starts form quality control (Lab). Lab personnel should carefully monitor
the moisture content of row materials.

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6. A) Unilap machine (Reiter Models E5/3 and E 30)
6. A.1. Introduction
Since combing is a very sensitive operation it needs proper feed otherwise it will affect the efficiency of the
machine not only on combing but also on cleaning efficiency. In order to make a suitable feed to the combing
machine Unilap machines are used. The fallowing are the main functions of the machine.
Parallelization of the feed fibres:-
Parallelization of the feed fibres depends upon the draft between card and the combing machine. If
the fibres are not oriented (parallelized), then long fibres are presented to the circular comb as if they are short
fibres and they are therefore eliminated as noil. Therefore, noil level decreases with increase in parallelization of
the feed fibres. However, after a certain stage, it does not necessarily affect the quality of the yarn produced.
Sheet thickness
Apart from parallelization, thickness of the sheet also exerts influence on retaining power. Moreover,
some thickness is desired to have a good nipping action during combing. In addition, a thicker sheet gives
more production. However, too thick a sheet results in overloading the circular comb resulting in poor
efficiency of combing action.
Evenness of the Lap sheet:-
Slivers are not fed directly to a combing machine since the nipping by nippers would occur only on the
high points this would result in clumps of fibres being pulled out during combing. Therefore, laps are
prepared using preparatory machines such as sliver lap and ribbon lap machines and these laps are feed to the
combing machine. Sufficient doublings are required during the preparation of the laps so as to produce laps
with good uniformity. An even lap across the width gives a better clamping by nippers.
6. A.2. Operating Principle
Unilap machine is found before card machine in the Spinning mill for regular and continuous feed to
comber machine. It converts 28 cans of draw frame sliver having 4250m or if there are only 14 feeds the length
of the feed must be 1220 to 1230 meters, to produce a single lap having 280 meters.
The 28 cans are divided in to two sections by the creel mechanism. Each to 14 cans of sliver per creel.
These 14 cans are further divided into two groups for each side of the creel. So the first path (i.e. 14 slivers) are
drafted and mixed by a drafting system outside of the machine. The other group will be processed similarly.
Then both groups of slivers are combined by pressure rollers and they inter to the machine. The drafting

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Fig 6.A.1 Unilap Machine Front
part
arrangement is 4 top rollers by 4 bottom rollers. The top rollers are coated with hard plastic and got hydraulic
pressuring mechanism. The bottom rollers are made of steel and are fluted. The front roller to the entrance of
sliver to the drafting system is spirally fluted while the rest has axial flute.
At its entrance there are 6 big metallic rollers rotating with the same speed. These rollers, combine control
fibre movement, and guide the combined sliver to the coiling mechanism. The rollers also control the width of
the sliver so that it will not exceed the tube length. There is a cutting mechanism in front of the rollers which
cut the sliver when the required lap length is reached. Tube is package holding hard, tubular plastic.
When the required length is reached a weight sensor below the coiling mechanism and sends a signal to the
control panel so that the auto doffing mechanism is actuated. This moves a rail which carries a package holding
table. As the full tube exits an empty tube inters the machine automatically from reserve tube holding
compartment found under the table. The rail has a stopping mechanism using a hydraulic valve all
synchronized by control unit.
6. A.3 The two types of Unilap machines
There are two types of Unilap machines. Model E30 and Model E 5/3. The main difference between
these models is the creel arrangement though there dividing mechanism is similar. E 5/3 model has a positively
driven rotating guide rollers to the drafting system. Its top rollers put pressure on the sliver using dead weight.
Its outer drafting system is covered and creels are all shifted to one side using more space than the E30 model.
But there is only one machine of this model. The rest are E30 model machines which has a creel located along
Full Tube
Reserve tube
Table Hydraulic valve
Rail

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E.G 2010/11
the middle axis of the machine. Top rollers are negatively rotated, i.e., by friction between fibre and metal and
has sensors which detect metal to metal contact when ever feed is not present.
Fig 6.A.2 Creel types of A) E5/3 and B) E30 model Unilap
Machines
Cree
l
BA

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6. B) Comber (Penye) machine (Reiter model E 60H)
6. B.1) Introduction
Combing is a process in the spinning department of a textile mill whose main objectives are the removal of
short fibres and other incidental benefits such as removal of short fibres. Removal of short fibres leads to better
yarn quality in terms of high yarn strength, better evenness, as short fibres do not contribute much to the
strength or evenness and in fact, are negative factors in this regard. During combing process, as the fibre groups
are pierced through by the needles (or similar arrangements in modern combers), the fibres are thoroughly
parallelized; further, neps are held between the needles during combing and are passed onto the comber waste.
Similar is the case with regard to the seed coats and other foreign matter in the feed material which is all
removed during the combing process. Because of all the above factors, the yarn quality improves to a
considerable degree which is otherwise not possible.
Combing is a process by which the quantity of short fibres and remnant fragments of impurities present in
a carded or drawn sliver are minimized to give a clean sliver, with the vast majority of the constituent fibres in a
straightened and parallel state. Combing, therefore, makes possible the spinning of yarns of fine counts with low
irregularities and a cleaner appearance.
For the production of high-quality yarn meant for critical consumers who use the yarn in modern high
speed weaving and knitting machines and also for high value products, combing process becomes generally
indispensable, especially in medium and fine counts. For achieving critical export targets, again combing
becomes indispensable. For the production of polyester cotton blended yarns, the cottons are generally combed
prior to blending with polyester.
Fig 6.B.1 Comber machine

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Fig 6.B.2 A) Working machine with comber web B) Four rollers system
6. B.2. Operating Principle
The comber in Ayka is a single sided rectilinear type machine with 8 heads, each fed with the comber
lap. There are 11 machines with single delivery in order to accommodate the autolevelling equipment. Each
head of the machinery consists of a feed system, a circular combing arrangement which is partially covered with
segments of rows of needles, a top comb and a set of delivery rollers. The feed material is combed intermittently
- a small piece of material is combed (usually a length of 5 to 8 mm of comber lap is fed for each cycle of
combing) and the delivery rollers take hold of the material and piece them to form them into a sliver. The sliver
from each of the 8 heads is passed over a sliver table and they are combined before they are fed to a common
drafting system. The drafting system drafts the material and the sliver is coiled into a can or cans, depending on
the number of deliveries.
Comber combines 8 laps from Unilap machine and produces one comber lap which has 3500 meters
within 25mins. During this operation the lap will be cleaned, mixed and blended. In order to do this the comber
has 4 rollers. The first one helps to deliver the cotton to the cutter. The second one is used to soften cotton by
combing it. The third shapes and changes the lap to semi processed. The forth one is the deliver it to the coiling
mechanism which enhances the coiler efficiency by 8 times. Comber waste (Noil) value is preset in to the
machine by production department. It is usually 13% of the feed material.
When the lap is fed to the combing segment, the piece of lap is held tightly at one end and the needles
of the combing segment pass through the fringe combing out the short fibres, neps and foreign matter and also
parallelize the fibres. The combed material is then ready for piecing and before piecing is done, the tail portion
of the fringe is combed by a top comb which will otherwise be left uncombed. The delivery rollers take hold of
the delivered fringe of combed material and piece them with the previously combed material and form a
continuous sliver. For this operation, the delivery rollers - also called detaching rollers - have to rotate in
forward and backward direction for every cycle of combing.
Lap is unrolled by the rotation of the fluted roller (13 in Fig 6.2). The sheet is fed over the eccentric shaft
(14); this eccentric shaft is rotated intermittently forward and backward in sequence with the nipper cycle. As

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the nipper assembly with the feed rollers moves forward and backward, the distance between the fluted lap
rollers and the feed rollers increases and decreases. The eccentric shaft compensates these changes and keeps
the lap at a constant tension.
The lap to be used is controlled through the tap feed rolls and the lap sheet (1) is introduced into the feeding
roll (2) the nippers (3) and the feeding roll perform backward and forward motion. During the forward motion,
the upper part (4) of the nippers opens and during the backward motion doses again. As a result of this
movement, the feeding rolls are driven and feed the lap sheet step by step over the end of the bottom nippers
(5). The nippers clamp the lap sheet, which is combed from below by the circular comb (6). Short fibres, which
are no longer clamped between the nippers ding to the circular comb. The brush (7) cleans the circular comb of
the dinging fibres, which are then pulled off by suction.
The long fibres will be taken over by forward and backward motion of the detaching rollers (9). The web
produced is formed into a sliver in the condenser (11) of the calendar rollers. The slivers from eight combing
positions are then guided into the draft system and coiled into the can.
6. B.3. Combing cycle
Essentially, rectilinear combing involves a sequence of five steps, termed the combing cycle, which is repeated
continuously while the machine is operating. The steps are as follows:
1. Feeding a fringe of several slivers to a rotating cylinder or drum covered with pins.
11 condensers
10 calendar
rollers
9 Detaching
rollers
8 waste reservoir
7 Brush
6 circular comb
1 Lap sheet
2 Feeding roller
3 Nipper
4 Upper part
5 Bottom Nipper
Fig 6.B.3 Inside parts of comber machine
12 Feed Lap
13 Lap support roller
14 eccentric shaft

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2. Removing, with the pins on the rotating cylinder, the impurities and fibres not held within a nip line.
3. Releasing the remaining fibres in the nip and simultaneously inserting a row of pins across the width of
fringe.
4. Pulling the longer fibres through the row of pins and piecing them to the previously detached group to
form a new length of combed sliver.
5. Removing the impurities and extracted fibres from the rotating cylinder, making it ready for the next
cycle.
The combing cycle begins with the nipper plates in their backmost position (farthest position from the
detaching rollers) and closed so as to nip the sliver fringe. As shown in the figure, the feed roller is stationary,
and the top comb is in the up position, clear of the fringe. During the early stages of the cycle, the pins
projecting from the cylinder comb enter the sliver fringe and subsequently remove impurities and fibres not
held by the nipper plates. As the pins leave the fringe, the nipper-plate unit begins moving toward the detaching
rollers. The nipper plates start opening, the top comb drops into the fringe just in front of the nipper plates and,
as the latter becomes fully opened, the feed roller pushes forward a short length of fringe. By the time the
nipper plates reach the detachment setting, the detaching rollers will have formed an overlap and begun their
clockwise rotation. The leading ends of fibres panning the detachment setting will then be caught, and these
fibres are pulled through the interspaces of the top comb. The top comb prevents neps, impurities, and fibres
not spanning the preset distance from being dragged out of the sliver fringe by those being detached. It
effectively combs and straightens the
trailing ends of fibres being detached.
In the following cycle, the cylinder
removes, along with any neps and
impurities, fibres retained in the sliver
fringe that are not held by the nipper
plates.
Once detachment has taken place, the
nipper-plate unit returns to its backmost
position and, in so doing, the newly
formed length of fringe is nipped and
ready for combing. The top comb will
have returned to its up position. The
combing cycle is then repeated. Since,
in each cycle, the nipper plates have to
be closed for the cylinder to extract the
noil, a cycle may be referred to as a nip.
The combing frequency is therefore the
number of nips per minute, which is
normally stated as the combing speed.
Fig 6.B.4 Combing Cycle (movement of combing element and
fibre mass)

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Fig 6.B.6 Web through the
Trumpet
6. B.4. Formation of Sliver
The detaching rollers (R) on Fig 6.4 forward the pieced up web periodically. However, the same material must
be condensed through the trumpet into a sliver and withdrawn continuously. So, a reserve of material must be
formed periodically between the detaching cylinder 'R' and the withdrawing roller 'Z'. The web pan 'V' functions
as a web reservoir. During forward movement of the detaching rollers, the corrugated sheet is formed on this
pan and during the reverse rotation of detaching rollers, the web sheet is straightened. The web is passed
through the trumpet as shown in Fig 6.B.4.
The side collection places the piecing lines diagonally in the sliver, which
means that piecing defects will get distributed and the amplitude is reduced.
The slivers from the individual head come out and take a 900
turn in the
common sliver table as shown in Fig 6.B.5 and moves towards the drafting
arrangement. The distance travelled up to the drafting point can be varied by
adjusting at the turning point so that the piecing points of slivers can be
shifted relative to each other.
The drafting arrangement provides the required draft to the assembled
slivers from heads and produces the final sliver. The collected comber sliver
travels on a sensitive screen to the winding section. This metallic surface (T) is
weight sensitive and helps to determine the count of delivery. If the delivery
has more count, it will have more weight so it pushes the screen with more
pressure. Since the correct weight for that length is calibrated, if it exceeds this
weight the sensor will send a signal to the control unit to automatically stop
the machine.
Fig 6.B.6 Top view of Combing machine

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No Problems were observed at the above machines.
7) ROVING FRAME
7.1 Introduction
Roving frames is a machine which comes after Finisher Draw Frame and it drafts the stock by means of
drafting rolls, twist it by means of a flyer, and wind it onto a bobbin. A roving is a continuous fibrous strand
drafted from a sliver and given cohesion by either inserting a small amount of twist or compacting the fibers with
an oscillating apron. It is drafted and twisted to be spun into a yarn.
Functions of the roving frame
The required high draft in the ring frame .Sliver is thick, untwisted strand that tends to be hairy and to
create fly. The drafting arrangements of ring frames are not capable of processing this strand in a single
drafting operation to create a yarn that meets all the normal demands on such yarns.
Attenuation of the sliver
Insertion of protective twist to the roving since the resulting fine strand has scarcely any coherence,
Winding of the roving into a package (bobbin) that can be transported, stored and donned on the ring
spinning machine.
Draw frame cans are not convenient for transport and presentation of feed material to the ring frame. In
ring frame, distances between spindles are much less and so feeding with sliver requires a large number
of rows of cans to be positioned behind the frame.
7.2 Operating Regions
7.2.1 Creel
Fiber to fiber cohesion is less in finally drawn sliver,
particularly for combed silver. Rollers in the creel can
easily create false drafts. Positively driven hexagonal
rollers are often used to guarantee transport of sliver
without slippage in order to prevent false draft.
Fig 7.1 Heptagonal Creel

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7.2.2) Drafting Region:
In the production of a roving, a 3-over-3 roller drafting system is used to attenuate the sliver. Unlike the
drawing operation, the slivers are drafted separately and, since
there are now fewer fibers in the cross section, alternative means to
a pressure bar is used for control of floating fibers. The most
commonly used is the double apron drafting method, illustrated in
Figure 7.2. As shown, this is a two-zone drafting arrangement in
which a pair of endless aprons is positioned in the high-draft front
zone and made to move at the surface speed of the middle-roller
pair. As fibers enter the high-draft front zone, the aprons will hold
them and assist in keeping them moving at the surface speed of the
middle rollers, while preventing the short-fibers being dragged
forward by those fibers nipped and accelerated by the front rollers. By comparing the speed profiles of the
floating fibers, it can be seen that the distance over which the motion of the short-fibers is uncontrolled has
been reduced, thereby minimizing the prominence of the drafting wave. Top roller weighting can be carried out
by Pneumatic pressure.
Aprons are used to guide and transport fibers during drafting. They are made of leather or synthetic
rubber. They are usually about 1mm thick. They should extend as closely as possible to the nip line of the front
rollers. The guiding length, referred to as the cradle length, must be adapted to the staple length.
Condensers are mounted on a reciprocating bar except those located in
the main drafting field which rest on the moving fiber strand without being
fixed. The traverse motion spreads wear evenly over the whole width of the
roller coatings. The purpose of condensers is to bring the fiber strand back
together again because during drafting, it continually tends to move apart.
Spreading fiber masses cause: roving unevenness, high fly levels and roving
hairiness. Condensers should be adapted precisely to the volume of the
fiber strand.
The draft often has limits not only at the upper limit, but also at lower
limit. If drafts below these lower limits are attempted, then the fiber masses
to be moved are too large, the drafting resistance becomes too high and the
drafting operation is difficult to control. Fig 7.3 overview of drafting
system
Fig 7.2 Drafting System

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7.3.3 Spindle and flyer
Flyer inserts twist. Each flyer rotation creates one turn in the roving. Twist per unit length of roving depends
upon the delivery rate. Higher levels of roving twist, therefore, always represent production losses in Roving
frame and possible draft problems in the ring spinning machine. But very low twist levels will cause false drafts
and roving breaks in the roving frame as well as in the ring frame. As the flyer rotates with the centre spindle,
twist is inserted into the drafted ribbon issuing from the front rollers of the drafting system, thereby forming the
roving. The contact between the roving and the rim of the flyer inlet imparts an added false twist, which
strengths the roving length between the flyer and front drafting rollers, permitting a low value of real twist to be
used. The roving, which is threaded through the hollow of the fly and around the presser arm, is pulled and
wound onto the bobbin by the rotation of the hollow spindle. To do so, the hollow spindle rotates at a higher
speed than the centre spindle, and the rail lifts and lowers the bobbin past the presser arm to build successive
layers of roving coils and make a full bobbin.
Apart from inserting twist, the flyer has to lead the very sensitive strand from the flyer top to the package
without introducing false drafts. Flyers have a very smooth guide tube set into one flyer leg and the other flyer
leg serves to balance the flyer. The strand is completely protected against air flows and the roving is no longer
pressed with considerable force against the metal of the leg, as it is in the previous designs having groove in the
flyer leg. Frictional resistance is considerably reduced, so that the strand can be pulled through with much less
force; this reduces false drafts and also reduces strand breaks while allowing a high speed of operation; however,
piecing is bit difficult.
Centrifugal tension is created at the bobbin surface as the layers are being wound and is created by the
rotation of the package. Each coil of roving can be considered as a high-speed rotating hoop of roving on which
centrifugal tension increases with increasing diameter of the package. Centrifugal force acts in such a manner as
to lift the top roving strand from the surface of the package so that the radial forces within the strand that hold
the fibres together are reduced and the roving can be stressed to the point of rupture. Breaks of this type occur
at the winding-on Point of the presser arm or in strands that have just been wound on the top surface of the
package.
The pressure arm guides the roving from the exit of the flyer leg to the package. The roving is wrapped
two or three times around the pressure arm (A&B in Fig 7.3) If it is high, then a hard compact package is
obtained. If it is too high then false drafts or roving breaks can be caused. The number of wraps depends upon
the material and twist level.
Fig 7.3 Pressure Arm guidance

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All the Roving frame machines in Ayka are top
mounted flyer types. Which means the flyer gets is
motion at its top via gears and shafts connected to the
motion transition form cones. This is simple in design
and easy to drive. However, inserting and removing
bobbins require removing the flyer each time and so
automation is not possible. The flyer is supported by ball
bearing at the neck and is delivered by gear wheel or
toothed belts from above. Drive by toothed belts from
top is shown in Fig 7.4.
The bobbins are arranged in the delivery section in two rows one behind
the other with the bobbins of one row offset relative to those of the other.
This is extremely economical in space. False twisters are used on the top of
the flyers to add false twist when the roving is being twisted between the front
roller and the flyer. Because of this additional twist, the roving is strongly
twisted and this reduces the breakage rate. Spinning triangle is also reduced
which will reduce the fibre fly and lap formation on the front bottom roller.
Because of the false twister, the roving becomes compact which helps to
increase the total length wound on the bobbin. Also this compactness helps to
increase the flyer speed
7.3.4Roving Stop motion:
Roving stop motions work on light beam principle. Light beam is
usually directed straight past the flyer top. In the event of roving break, the broken roving end whirls around the
flyer top and interrupts the light beam and activates the stop motion.
7.3.5 Pneumatic suction:
Pneumatic suction is used in roving frame to suck the fibres coming out of the front roller in the event of
roving breakage. The suction system is necessity in order to avoid a series of roving breaks along a bobbin row
following the first break in the row. Once the roving breaks, the fibres from the drafting system are sucked and
fibres pass though a capacitor to the collecting system. Bobbin doffing, since bobbin doffing is a costly,
frequent and labour intensive operation that decreases efficiency. Cleaning: by means of cleaning aprons, clearer
rollers and suction systems at the drafting arrangement and also by the travelling blowers that keep the machine
clean and Machine monitoring (stop motions) are automated.
Fig 7.4 Top mounded Flyer
Fig 7.5 Effect of false Twister to
adjust roving angle (Spinning triangle)

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7.3.6 Cone drive transmission
Variation of the bobbin rotation rate originates in the cone transmission and occurs in small steps owing
to shifting of the cone belt after each lift stroke. The bobbin rotation must be changed in accordance with a
linear function.
There are two types of cones: Straight-sided and hyperbolic cones. Straight-sided cones are simple to
design, but the belt must be shifted in varying magnitude (the initial steps being relatively large and the later
ones smaller) to change the transmission ration in a linear manner and thus give the required linear variation in
the bobbin rotation rate.
Ayka uses hyperbolic cones are convex on the upper driving cone and concave on the lower driven cone.
The belt is shifted in constant amounts, but it is difficult to design and during winding, the belt is always moved
on surfaces of varying. Shifting of the belt is under the control of the ratchet wheel. After each stroke, the
ratchet wheel is permitted to rotate by a half tooth. This movement is transmitted to the belt guide by means of
a gear train including change wheels. The tensile force required to induce shifting of the belt is exerted by a
weight.
The bobbin diameter increases more or less rapidly depending upon roving hank. The amount of shifting,
which depends on the thickness of the roving, is modified by changing the ratchet wheel or by substitution of
change wheels. If a ratchet wheel with fewer teeth is inserted, then the belt is shifted through larger steps, i.e. it
progresses more rapidly and vice-versa. When the bobbin is fully wound, the belt must be moved back to its
starting point.
7.4 Operation Sequence
The first operation is drafting. Slivers from the draw frame cans are feed over the creel to the drafting
arrangement. The drafting system attenuates the sliver in to a roving. The next operation is twisting. Twisting
is done by the rotating flyer and twists are transmitted into the unsupported length between the flyer and the
delivery of the drafting arrangement. To ensure that the roving is passed safely and without damage, it runs
through the hollow flyer arm and is wound 2-3 times around the pressure arm before winding on the bobbin.
Bobbin and flyer are driven separately, so that winding of the twisted strand is carried out by running the
bobbin at a higher peripheral speed than the flyer. The bobbin rail is moving up and down continuously, so
that the coils must be wound closely and parallel to one another to ensure that maximum material is wound on
the bobbin. Since the diameter of the package increases with each layer, the length of the roving per coil also
will increase. Therefore the speed of movement of bobbin rail must be reduced by a small amount after each
completed layer. Length delivered by the front roller is always constant. Owing to the increase in the diameter
of the package for every up and down movement, the peripheral speed of package should keep on changing to
maintain the same difference in peripheral speeds between package and flyer.

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7.5 Problems and Recommendations
1) Roller lapping has been a major problem in the Roving frame machines. There is a continuous stoppage of
machine due to breakages sliver due to this. This will increase down time of the machine.
This is the same problem occurring at Draw frame machines. The cause is high moisture content of the
sliver. Not only has it had the effect of roller lapping it is not good to the machines because moisture will cause
rusting of some surfaces. This can be solved by adjusting the Relative Humidity of the room so that more
moisture is removed from the slivers by convection. If the room Rh% is less moisture from the slivers will be
forced to move out of the sliver and into the surrounding air.
2) Bobbin count variation
The most important single cause of within-bobbin count variation is defective draw frame drafting
Differences in blow room lap weight over long periods that are unlikely to be evened out by subsequent
doubling, Draft or waste differences between groups of cards or combers whose slivers are processed in
isolation without inter-doubling, Hank differences between draw frame slivers, Draft differences between fly
frames, Irregular control of bobbin speed, Poor drafting introduces pronounced differences in the length of first
head sliver and finisher sliver which lead to variations in count between consecutive leas of the yarn from the
same bobbin.
The contribution to within-bobbin count variation of Roving frames can be from two sources: irregular
drafting (not much because it will introduce variability between small lengths of roving that will be averaged out
in a 5m piece of roving which roughly corresponds to a lea of yarn) and irregular stretching. The effect of
irregular stretching caused by inherent design deficiency, wrong choice of ratchet wheel and improper regulation
of bobbin speed can introduce differences in the weight of roving over different layers of the roving bobbin.
Stretch limit during the build of a bobbin is +2%. Causes of excessive stretch at fly frames are less twist in the
roving, incorrect initial position of the cone drum belt, winding wheel not appropriate to match the bare bobbin
diameter and incorrect lifter wheel which gives either too many or too few coils per unit length on the bare
bobbin.
To solve the above problem the fallowing measures are recommended.
To Control of blow room lap weight over intervals of approximately half days
Ensuring uniformity of waste levels and drafts on cards and combers
Ensuring uniformity of draft over draw frames and fly frames
Keeping the hank differences between front and back row bobbin at a minimum level
Good control of bobbin speed
Creeling of ring frames entirely with front or back row bobbin with a suitable change in ring frame draft

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8) Ring Frame
8.1 Introduction
The tasks of ring spinning are:
 To attenuate the input material (roving) to the linear density (fineness) required in the final yarn.
 To insert the required amount of twist in order to impart strength to the fibre strand.
 To wind up the yarn onto a package; this is suitable for handling, storage, transportation and is capable
of being unwound at high speed in the subsequent processing.
8.2 Principle of operation
Roving bobbins (1) are creeled in appropriate holders (3). Guide rails (4) lead
the roving (2) into the drafting arrangement (5) which attenuates them to the final
count. The drafting arrangement is inclined at an angle of about 45-600
. It is one
of the most important assemblies on the machine since it has considerable
influence on irregularities in the yarn.
Upon leaving the front rollers, the emerging fine fibre strand (6) receive the
turns of twist needed to give it strength. This twist is generated by the spindle,
which rotates at high speed. Each revolution of the spindle imparts one turn of
twist to the strand. Spinning of the yarn is thus complete.
In order to wind up this yarn on a bobbin tube carried by the spindle (8), a
traveller (9) is required to cooperate with the spindle. The traveller-a remnant of
the flyer in the roving frame-moves on a guide rail (the ring (10)) encircling the
spindle.
The traveller has no drive of its own; instead, it is carried along by the yarn
it is threaded with. The rotation rate of the traveller is lower than that of the
spindle owing to significant friction generated between the traveller and ring, and
also because of air drag on the yarn balloon formed between the thread guide (7)
and the traveller (9). This difference in speed between the spindle and
traveller enables winding of the yarn on to the tube. In distinction to the roving frame, a ring spinning
machine operates with a leading spindle.
Fig 8.1 Principle of operation

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Apron
Winding of the yarn onto a cylindrical package is affected by raising and lowering of the rings, which
are carried on a longitudinal ring rail. The travellers stroke of the ring rail is less than the total winding height
(lift) on the tube. The ring rail must therefore be raised by small amount after each layers of coil. At one time,
machine were built in which the lifting motion was achieved not by raising the ring rail but by lowering the
spindle rail (lowerable spindle rail). Such machines are no longer commercially available.
8.2.1Drafting
Roller drafting arrangement is usually used.
Drafting system is generally consisting of three lines of rollers with aprons mounted on the middle rollers.
A single weighting arm holds the top roller assemblies in position above the bottom rollers.
Pressure is applied by spring system.
The pressure provides the force to grip the fibres at the roller nips and to rotate the
top rollers when the bottom rollers are driven.
There are two drafting zones; namely the back zone and the front zone.
The total draft is distributed between the two drafting zones.
The largest draft occurs in the front zone. It is for this reason that the
aprons are positioned in this zone. The use of aprons is to control fibre
movement, particularly the short fibres and so to limit the level of added
irregularity caused by drafting waves. The aprons have the effect of extending
the control point of the middle rollers almost up to the nip of the front
rollers, thereby reducing the proportion of fibres and minimizing
uncontrolled fibre movement
8.2.2 Ring and Traveller
Ring diameter, flange width and ring profile depends upon the fibre, twist per inch, lift of the machine,
maximum spindle speed, winding capacity etc. Operating speed of the traveller has a maximum limit, because
the heat generated between ring and traveller should be dissipated by the low mass of the traveller with in a
short time available.
If the cotton combed yarn is for knitting, traveller speed will not be a limiting factor. Since yarn mmTPI is
less, the yarn strand is not strong enough. Therefore the limiting factor will be yarn tension. Following points to
be considered
Fig 8.2 Drafting arrangement
Pressure arm

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1. If winding is a problem, it is better to go for reduced production with bigger ring diameter.
2. Anti-wedge ring profile is better, because of better heat dissipation
3. Elliptical traveller should be used, to avoid start-up breaks in hosiery counts
4. special type of traveller clearer can be used to avoid accumulation of fibre on the traveller as traveller
with waste does not perform well during start-up.
For polyester/cotton blends and cotton weaving counts yarn strength is not a problem. The limiting factor will
be a traveller speed. For a ring diameter of 40 mm, spindle speed up to 19500 should not be a problem. For
spindle speeds more than 20000 rpm, ORBIT rings or SU-RINGS should be used. As the area of contact is
more with these rings, with higher speeds and pressure, the heat produced can be dissipated without any
problem. Normal ring and traveller profile will not be able to run at speeds higher than 20000 to produce a
good quality yarn. ORBIT rings will be of great help, to work 100% polyester at higher spindle speeds. Because,
of the tension, the heat produced between ring and traveller is extremely high. But one should understand that,
the yarn strength of polyester is very high. Here the limiting factor is only the heat dissipation.
Therefore ORBIT RINGS with high area of contact will be able to run well at higher spindle speeds when
processing 100% polyester.
While running 100% cotton, the fibre dust in cotton, acts like a lubricant. All the cottons do not form same
amount of lubricating film. If there is no fibre lubrication, traveller wears out very fast. Because of this worn out
or burn out travellers, micro welding occurs on the ring surface, which results in damaged ring surface, hence
imperfections and hairiness increases in the yarn.
Lubrication is good with West African cottons like Burkina Faso. It may not be true with all the cottons
from West Africa. In general cottons or from very dry places, lubrication is very bad. If the fibre lubrication is
very bad, it is better to use lighter travellers and change the travellers as early as possible.
Traveller life depends upon the type of raw material, humidity conditions, and ring frame speeds, the yarn
count, etc. If the climate is dry, fibre lubrication will be less while processing cotton. Traveller life is very less
when Viscose rayon is processed especially semi dull fibre, because of low lubrication. Traveller life is better for
optical bright fibres. Traveller life is better for Poly/cotton blends, because of better lubrication between ring
and traveller. Because of the centrifugal force exerted by the traveller on the yarn, the particles from the fibre
fall on the ring where the traveller is in contact. These particles act like a lubricating film between ring and
traveller.

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8.2.3 Rubber Cots and Aprons
For processing combed cotton, soft cots or hardness of top rollers are used. There are different types of
cores (inner fixing part of a rubber cot) available from different manufacturers. Aluminium core, PVC core, etc.
It is always better to use softer cots with aluminium core.
When softer cots are used, buffing frequency should be reduced to 45 to 90 days depending upon the quality
of the rubber cots, if the mill is aiming at very high consistent quality in cotton counts.
If the lapping tendency is very high when processing synthetic fibres for non critical end uses, It is better to
use 90 degree shore harness cots, to avoid cots damages. This will improve the working and the yarn quality
compared to working with 83 degree shore hardness.
If rubber cots damages are more due to lapping, frequent buffing as high as once in 30 days will be of great
help to improve the working and quality. Of course, one should try to work the ring frame without lapping.
If the pressure applied on the roller is more, then lapping tendency will be more. Hence fine and longer
fibres will have more tendencies for lapping because of high top roller pressure required to overcome the
drafting resistance.
The closer the setting between the suction nozzle and the bottom roller, the higher the suction efficiency
and lower the lapping propensity.
Higher roving twist will reduce the lapping tendency to some extent. Therefore it is better to have a slightly
higher roving twist, provided there is no problem in ring frame drafting, when the lapping tendency is more
With Softer rubber cots lapping tendency will be more due to more surface contact.
The air conditioning system of Ayka ring frame is temperature 29.9degree centigrade and RH% of 46.6%
The small pores, pinholes in the rubber cots or impurities in the cots can cause lapping. Therefore the quality of
buffing and the cots treatment after buffing is very important. Electrostatic charges are troublesome especially
where relatively large amount of fibre are being processed in a loose state e.g. draw frame, card etc. Lapping
tendency on the top roll increases with increasing relative humidity. The frequently held opinion is that
processing performance remains stable at a steady absolute relative humidity, i.e. at constant moisture content
per Kg of dry air.
8.3 Twist
The strength of a thread twisted from staple fibres increases with increasing twist, upto certain level. Once it
reaches the maximum strength, further increase in twist results in reduction in yarn strength. Coarser and
shorter fibres require more Twist per unit length than finer and longer fibres. Twist multiplier is a unit which
helps to decide the twist per unit length for different counts from the same raw material. This is nothing but the
angle of inclination of the helical disposition of the fibre in the yarn.

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Very long creel heights in ring frame, lower roving T.M. and heavier roving package will result in many long
thin places in the yarn.(especially in combed hosiery counts). In general 16 x 6 " bobbins are used. This helps to
increase the spare rovings per machine with higher creel running time. Therefore one should aim at increasing
the bobbin weight as well as increasing the number of spare rovings in the ring frame. Normally 6 row creels
are used in Ayka (around 150 rovings for 1000 spindle machine). Creel height should be as low as possible for
cotton combed counts. Spare roving will improve the operators‘ efficiency.
Four spindle drive is advantageous, because small variation in machining accuracy of bolster, spindle
beam etc will affect the spindle speeds, thereby the twist per inch. Waste accumulation between contact rollers,
bent contact rollers, damaged contact rollers, oil spilling from any one spindle etc. will affect the spindle speeds
and thereby TPI. The spindle speed variation between spindles in a 5 year old ring frame will be very high in
case of tangential belt drive compared to 4 spindle drive. Noise level and energy consumption will be low in 4
spindle drive.
There are 19 ring frame machines in the first section and additional 7 ring frames in the other section. But
all the ring frames are not the same types. G30 and G33 Reiter types. They have basic similar mechanisms.
Rieter G 33 ring spinning frame incorporates a number of automatic devices. First is the SERVOgrip which has
been described as a revolutionary doffing method. With this device doffing can be performed without the
objectionable under winding which may give rise to yarn faults and end-breaks. Second is the FLEXIdraft which
is a multi-motor drafting mechanism which eliminates manual change of gears for regulation of draft and twist
whenever count changes are required. Changes in the main draft, yarn twist and cop build-up are performed by
manipulation of controls at the machine control panel. The third automatic device is the automatic doffing
system itself called the ROBO doff which is self monitoring with a doffing time of 1 min. 50 sec. Fourth is the
ROBO load which is in fact a cop removal and tube-loading system. The G 30 type has a changeable gear. We
have to change the gears to change parameters of the yarn.
All the ring frames got an auto doffing mechanism which helps the operators since there are 1008 spindles
one each mechanism and the machine is about 40 meters long.
Fig 8.3 Ring Frame

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8.4 Recommendations
When processing coarse counts at higher speeds, the air current below the machine is a big problem
with 4 spindle drive. This is due to the more running parts like tin rollers and jockey pulleys. This will lead to
more fluff in the yarn, if humidification system is not good enough to suck the floating fluff. So suction ststem
must be monitored constantly.
If spindle speeds are high for cotton counts, every end breaks will result in more fluff in the department
due to the free end of the yarn getting cut by the traveller when the distance between traveller and the bobbin
with the yarn is less. Higher the delay in attending the end break, higher the fly liberation. If the number of
openings of return air system for a ring frame is less and the exhaust air volume is not sufficient enough, then
fly liberation from an end break will increase the end breaks and thereby will lead to multiple breaks. End
break due to a fly entering the traveller will get struck with the traveller and will result in heavier traveller
weight and that particular spindle will continue to work badly.
Multiple breaks are very dangerous, as it will result in big variation in yarn hairiness and the ring frame
working will be very badly affected due to heavier travellers because of the fluff in the traveller.
Dry atmosphere in ring frame department will result in more yarn hairiness, more fly liberation and more end
breaks. .
If the total draft is more than or the fibre length is more than and the fibre is a fine fibre (i.e. more
number of fibres in the cross section) with a very high inter fibre friction, more break draft than is used. For
most of the application, lower break draft with wider setting is used. With higher break drafts, roller setting
becomes very critical. Higher the break draft, higher the chances for thin places. Higher draft with improper
back zone setting will lead to thin places and hence more end breaks even though more twist flows into the thin
yarn.
Defective bottom apron and top roll make the spindle a sick spindle which will be prone to end breaks.
A wider front zone setting will increase the imperfection and Uster, but there will not be major deviations of
yarn quality. Nose bar height setting is very important. Depending upon the design, it is 0.7mm or .9 mm.
Variation in height setting will affect the yarn quality and the apron movement. The distance between nose bar
and middle bottom roller should be less than apron thickness or more than 3 mm to avoid apron buckling if
there is any disturbance in apron movement.

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9) Winding
9.1 Introduction
The principal objective of winding is to assemble many meters of yarn into package form suitable for use in
subsequent operations such as weaving and knitting. A suitable package is one that can be easily unwound at
high speed. Faults like very thick and very thin places in the yarn length should be removed, but the number of
joint ends (i.e., piecing) must be kept to a minimum and, when required, a lubricant (wax) should be applied to
the yarn surface. The yarn on packages for high-speed weft knitting is usually waxed. The removal of faults
from the yarn is known as clearing and, in practice, clearing and waxing are important aspects of winding.
In the case of most unconventional spinning systems, the yarn is cleared, waxed, and wound into a suitable
package during spinning. As an example, Figure 9.1 illustrates the situation for rotor spinning. With ring-
spinning systems, there is insufficient yarn length on the ring-spinning package. The yarn is therefore removed
from a number of such packages and rewound into a suitable one. As the yarn is removed from the ring bobbin,
it will balloon, which can increase the yarn hairiness. The yarn therefore passes through a balloon controller, and
then via several tension control devices, followed by the yarn clearer, which cuts sizeable faults from the yarn. A
piecing device joins the cut ends, and the yarn then travels via a waxing unit before being wound into a package.
Two basic actions are required when producing the package. A bobbin forming the core of the package
must be rotated so that the yarn, while under tension, can be wrapped around the bobbin circumference.
Simultaneously, the point at which the yarn is wound must be traversed along the bobbin length. Control of the
yarn position can therefore be achieved by regulation of the traverse in relation to the package rotation. In this
way, concentric yarn layers can be made to build up to form the package. Bobbins may be made of card or
plastic, the latter being perforated if the yarn is to be package dyed. Parallel-sided cheeses have tubular bobbins.
For cones, the bobbin is of a conical form, i.e., a truncated cone; the angle of taper — the semi-vertical angle —
depends on the end use for the resulting package. Ayka uses conic package type.
Ayka uses Random winding which is suitable for most staple spun yarn which includes cotton, viscose and
polyester; the yarn package is driven by contact with a driving drum. The yarn may be traversed by a grooved
driving drum.
The traverse velocity and surface velocity are constant and then it produces a constant angle of wind and a
constant winding rate. The rotational speed of the package will decreases as its diameter increases because of the
relation
Different kinds of cones are produced in Ayka from hard paper and glue in ―Carton Room‖ located in
knitting department. The comes taper differ and is shown in the figure below.
TABLE 9.1Common Tapers for Random-Wound Cones
Cone taper (semi vertical angle) Uses
5°5' Weft knitting: at final diameter taper may increase to 10°
9°1' Weft knitting: at final diameter taper may be 14° to 18°

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FIGURE 9.1
A) yarn movement across winding machine parts
B) Ring-spinning package and rewound yarns of cone
packages.
C) Winding traverses motion.
A
C
B

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9.2 Operating Regions
9.2.1 Drum winding
Drum-winding machines rotate the forming package through surface contact with a cylindrical drum, and
the yarn is traversed by a wing cam, or by grooves in the drum. As shown, the end, B, is made to move around
the periphery of the cam, traveling one circuit of the periphery per revolution of the camshaft. As the yarn
makes one circuit of the cam, A reciprocates, moving the yarn through a return traverse (i.e., double traverse)
along the length of the bobbin. The reciprocating yarn guide limits the winding speed because of the inertia on
reversals. A very high rate of traverse is impeded by the mechanics of the guide system, since forces of 16 to 64
times the weight of the yarn guide can be present during the reciprocating action.
Speeds in excess of 1500 m/min can be achieved. A further advantage of the grooved traverse roller is that,
as a result of tension, the yarn being wound enters the groove without the need for threading up as is required
with the independent traverse system.
With the grooved drum system, the surface speed of the drum, and the traverse speed are kept constant. A
continuous helical groove (i.e., interconnected clockwise and counter clockwise helical grooves) around the
drum circumference guides the yarn along the traverse length as the yarn is wound onto the bobbin
A continuous helix has points of crossover of the clockwise and counter clockwise helices. To retain the yarn in
the correct groove during its traverse, particularly at the intersections, one groove is made deeper than the other,
and the shallower groove is slightly angled.
9.2.2 Splicing
There are various methods of producing a knot-free yarn joint (e.g., gluing, wrapping, and welding) but,
with spun yarn, only the splice has proved to be a suitable replacement for the knot. The principle for splicing
two yarn ends is to untwist a short length at the ends and then intermingle and retwist together the fibres of the
two ends. Electrostatic and mechanical techniques have been used for splicing but were unsuccessful because of
the complexity of the devices, the time required to make the splice, and, importantly, the very low strength of
the joint.
Splicing devices currently employ air jets to untwist, intermingle, and retwist the fibres. Figure 9.2 illustrates
the basic actions of the splicing process. The device has two untwisting tubes (A, B) and a twisting chamber (C).
The two yarn lengths to be joined are held on opposite sides of the twisting chamber at N1 and N2, while their
free ends L1 and L2 are placed respectively into the tubes B and A. The lengths lie parallel to each other within
the respective twisting chambers.
FIGURE 9.2 Splicer Mechanism

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This is the arrangement for untwisting the yarn ends by the air vortices generated by a pulse of compressed
air injected through nozzles into A and B. The lengths L1 and L2 are then drawn back until there is a certain
length of overlap of the untwisted ends within the splicing chamber. A pulse of compressed air is then injected
through other nozzles into the chamber, and the resulting vortex entangles and twists together the fibres of the
overlapping ends to form a spliced piecing. Winding of the yarn then continues.
9.2.3 Yarn Waxing
It is common practice to wax staple-spun yarns for knitting applications, given the problems of friction
associated with the many thread line deflection points of the thread guides and the knitting needles on knitting
machines. For optimal running of yarns during knitting, there needs to be a uniform wax distribution along
yarns and a minimum of wax rub-off. The amount of wax deposited on the yarn has a marked influence on the
dynamic frictional characteristics of the yarn. The preference with the commonly used wax disc is for a coarse
microcrystalline structure, which allows small wax particles to be removed and held onto the yarn surface, as
this should enable a uniform distribution of deposition. Steaming or high-humidity conditioning of wax yarns
can result in an increased friction coefficient. Steaming will melt the wax particles and also give a partial
penetration of wax into the yarn. If the yarn has to be relaxed in this way, then the deposition should be
increased to offset the effect.
9.2.5 Yarn Clearing
Yarn clearer is a device which detects and removes yarn faults. When thick places of yarn pass through the
measuring device, the change in capacitance caused by the change in yarn thickness is converted in voltage
oscillation which is amplified and actuates the cutting mechanism. The device used to detect faults is called
Uster Quantum and it works with splicing unit through the control panel. It cuts yarn off when ever it has
defects like hairiness or higher count.
FIGURE 9.3 Splicer Unit

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9.2.4 Compensation type (Gate type) tensioning device
Fig 9.3 shows one movable comb held by weight and the other is fixed. If the tension of yarn is high, then the
comb will move inside to decrease the angle of yarn and vise-versa.
There are two models of winding machines the Murata 7- II Machconer / Linkconer type Fig (9.4 B) which
has one knotter per spindle , one winding unit that can be removed for maintenance and replaced by another
with out interfering the production on the other spindles in the machine and has automatic doffing. This
machine is an individual spindle type automatic winder (Individual spindle driving type), and performs one cycle
of yarn joining in nine seconds. It is a fully automatic winder and can be equipped with the CBF (Continuous
Bobbin Feeder) (Fig 9.4 C) which adjusts the tube to be proper feed to the machine by adjusting its shape, or
cutting extra yarn on it, and filling empty tubes with suitable yarn length, the MMM-MK8 or MMC/2yarn
length and data device. This machine is of two types;
 Magazine Type in which an operator supplies the spinning bobbins
 Bobbin tray Type in which CBF automatically supplies the spinning Bobbins
9.3 Steaming (Walker APS 7 machine)
Gate type feeler
Photoelectric
feeler
Pre-cleaner
dial
FIGURE 9.3 Gate type tensioner
FIGURE 9.4 Winding machines of Both types A&B C) CBF
B
-
cl
ea
n
er
di
al
C
-
cl
ea
n
er
di
al
A
-
cl
ea
n
er
di
al

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After the yarn winding process the cones are collected on a creel which holds about 50 cones and are
transferred to the steaming room. The main function of steaming the cones is to impart strength and regularity
of the yarn.
The steaming process takes place in 4 steps. First is the feeding. The machine has automatic rail (see fig) which
transports the creel into the internal body. The machine can accommodate 4 creels. The second part is the
adjustment of the heat exchanger. There is as separate room in which
heat is generated by an electrical system and water is boiled until steam
is produced. This steam is transported via pipes to the body of the
machine. Other chemicals are inserted through ducting system but
they are stored outside the room. It takes the about 40 minutes t
steam the cones with temperature of 40-60degree centigrade. At the
end of operation, there is an auto doffing system which will first adjust
the pressure in the body so that it is safe to open the door because
during steaming process the pressure can be up to 50bars. It can be
detected by the specific odor of baking bread; of course the odor is
specific for the receiver.
After the package is winded there is a quality monitoring device which
detects whether there is wrong color winded in the middle of the yarn
or of different count. This quality monitoring device works by focusing
UV light. This will expose whether there is a defect in the cone. The
defect can be seen as a horizontal line across the cone (fig 9.6)
9.4 Recommendations
After a yarn is dyed from Dyeing Department, it comes to Spinning department t be rewinded again. This is
unnecessary as rewinding can take place in the Dyeing Department and also it adds transportation time and
cost. There is plenty of space to install the machines.
There is only one operator for most of the machines. And as breakage happens the operator must fix every
problem across the machine length. This increases production down time. But if there are two operators, it will
increase the machine productivity by 32.5%. The calculation is beyond the scope of this paper.
FIGURE 9.5 Steaming
mahine
FIGURE 9.5 Cone quality monitoring
FIGURE 9.6 Defective cone (left) and normal cone

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10. Rotor (Reiter Model H 145)
10.1 Introduction
Ring spinning is the versatile machine and it remains the major type of machine for the production of
textile yarns. But it has certain disadvantages like
Due to the ring and traveller combination, the maximum achievable speed is limited. (The maximum traveler
speed achievable with the present technologies is of the order of 40 meters per second).
Spindle speeds of above 28,000 revolutions per minute are also not possible with the available technologies. In
addition, the energy consumption due to higher spindle speeds increases steeply, making the operation
uneconomical.
The yarn package also should rotate in order to carry out the twisting and winding operations simultaneously.
In short, high production rates are not realizable and the technology is rather saturated, at least for the
present.
Compared to ring spinning, rotor spinning system has the following advantages:
 High production rates (4–10 times ring spinning spindle) having a delivery speed of up to 200m/min. It
is more economical for yarn counts up to 40s
. Market share of rotor-spun yarns is around 20% of the
total staple-fibre-yarn production and is steadily increasing
 Elimination of processing stages such as draw frame (optional), roving frame and winding machines
 It is an excellent recycling device as it spins mill waste fibres (secondary materials)
 A relative is of automation (fully automated)
 A considerable reduction in personnel and space
Tasks of rotor spinning machine
1. Opening almost to individual fibres (fibre separation)
2. Cleaning
3. Homogenizing through back-doubling to improve evenness
4. Combining (forming a coherent linear strand from individual fibres.
10.2 Basic Principle of Open-End Spinning
Fully automated and in all other spinning systems, a stream of fibres proceeds continuously from the
feedstock to the take-up package without interruption, but with gradual attenuation. In rotor spinning (which is
one of open-end spinning systems), this flow of fibres is interrupted, the fibre strand being opened to individual
fibres at a predetermined position usually by means of an opening roller. This enables twist to be imparted by
rotation of the yarn end, which in turn leads to significantly higher speeds of rotation. However, the break in
fibre flow also leads directly to one of most important and difficult tasks in open-end spinning – the necessity to
re-collect the fibres to form a new fibre strand.
In conventional ring spinning, there is a continuity of material i.e. from the roving to drafting to twisting
to winding onto the ring bobbin; the material flow is continuous and uninterrupted. This makes it necessary to

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Fig. 10.2: Tangential Feeding
of fibres to the rotor
rotate the package also to get the ‗real‘ twist. In other words, the twisting element (traveller in ring spinning and
flyer in fly frame machine) and the winding element (ring bobbin in ring spinning and roving bobbin in fly
frame) need to rotate together.
If a discontinuity introduced in the material flow, it is sufficient to rotate the yarn end and a real twist will be
introduced for every rotation of the yarn end. This would mean that only twisting rotations are required and the
winding can be carried out separately. Twisting rotations by rotating the yarn end is easy as only a small amount
of mass is involved. A continuous flow of well-opened fibres are fed to the yarn end (Fig.1). The brush like
open structure of the yarn end grasps the fibres; the rotation of the yarn binds the fibres with an open end and
the fibres are twisted by the rolling action of the yarn end. It is only necessary to withdraw the yarn continuously
and wind it onto a package. (Generally a cross-wound package is obtained).
Formation of Yarn
After a ring of fibres is formed in the rotor groove, a free end of yarn is
introduced into the rotor. From the feed tube, the fibres are fed on the rotor wall
tangentially (Fig. 10.2). The open end of the yarn (which is introduced into the
rotor groove) is also subject to the enormous centrifugal force and is attached
firmly to the rotor groove. One end of the yarn is fixed to the rotor groove and
rotates along with the rotor. The other end of the yarn is fixed to the package.
Thus, a real twist is formed in the yarn.
Each rotation of the rotor inserts one turn of twist - i.e. each rotation
of the rotor induces the open end yarn to turn on itself through its axis. The
assumption to note is that there is no slip between the rotor and the rotating yarn.
The open-end of yarn as it rotates in its axis, starts binding the fibres in the groove and an open brush like
form is formed. The region where the fibres are being twisted into the open end yarn is called ―binding-in
zone‖. The length of binding in zone is an important factor. If it is too low, then there will be no yarn
formation. If it is too long, then the yarn formed will have a tight structure along with more wrapper fibres.
The withdrawal rate influences the length of binding in zone and for stable spinning, there should be a
minimum length and accordingly, there is a minimum twist factor below which it is not possible to spin the yarn
in rotor spinning.
Raw materials for Rotor Spinning
The following materials can be processed in rotor spinning:
Cotton
Cotton waste
Comber noil
Blends
Polyester and Blends of man-made and natural fibres

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Fig. 10: Types of rotor (Differ in
diameter)
10.3 Working principle
Normally, a draw frame sliver is fed. Direct feeding of card sliver is rare; feeding of single passage draw
frame sliver is possible but double passage draw frame sliver gives good results. Additional draw frame passages
ensure that micro dust is removed to a maximum extent; there are other advantages such as better evenness of
feed material due to doublings etc.
The sliver (A) to be the processed is fed through the feed funnel (B) to the feed plate (C). The feed roller
(D) moves the sliver to the opening roller (E). The surface of the rotating opening roller is covered with saw
tooth wire or needles. The opening roller is like a miniature lickerin; on its surface, it has needles or more
commonly metallic saw-tooth clothing (just like lickerin). The opener rollers run at very high speeds of the order
of 5000 to 8000 revolutions per minute. The fibre sheet (the beard) presented by the feed roller / feed plate
combination is combed or pulled out by the opener roller and separates them to individual fibres and are carried
along by the opener roller in its rotation. The fibres are carried away by wire points as they are light; but the
heavy particles due to high centrifugal forces are thrown out at the opening.
Opener roller has a high cleaning potential and accordingly, suction arrangements are provided to eliminate
heavy trash articles (seed coat fragments, heavy neps/slubs etc). However, micro dust escapes this cleaning
action. Micro dust (very small damaged cellulose particles / dust / mineral matter/seed coat fragments / leaf
particles etc) tend to be collected in the groove of the rotor as a sticky material; this prevents uniform
deposition of fibres in the groove of the rotor. Non-uniform deposition of fibres leads to uneven yarn and
ultimately to yarn break. Therefore, the sliver fed to rotor must have a very minimum amount of micro dust.
Note that ring frame spinning operation is not affected by the micro dust in this manner. (As far as larger trash
particles are concerned, they do not stick and are bound into the yarn; this results in a defective yarn but they do
not affect rotor working).
The opening roller separates the fibres of the sliver and guides them to the feed duct (F). Trash particles in
the feed sliver are removed by centrifugal force trough a trash removal opening onto a trash conveyer (G). The
sliver is opened almost to individual fibre state by the opener roller; this could be considered as the first draft in
the rotor spinning machine.
In both the head and foot ends nozzles suction off all extracted
particles. The feed tube converges from the opener roller end towards
the rotor end. The pressure gradient thus obtained increases the
acceleration of fibres in the feed tube. The converging tube (the feed
tube to the rotor) accelerates the movement of the fibres and this is the
second draft that is given to the fibres. The rotor wall runs at a faster
rate than the incoming fibres and fibres are deposited on the wall. This
is the third draft given to the fibres.
Now, a yarn end is introduced into the rotor so that it touches the
groove of the rotor. The open end of the yarn is also subjected to the
very high level of centrifugal forces and is firmly attached to the rotor
groove and the free end of the yarn rotates along with the rotor. The fibres are deposited on the rotor wall in
the form of layer over layer and fibred over fibred. The fibres are being ―doubled‖ and this action is called
―back doubling‖ as the fibres are completely individualized and then fed over one another. The doubling action
is being carried out almost on individual fibre basis (not groups of fibres laid over groups of fibres). This results

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Fig. 10.4: Internal parts of rotor
in an extremely even yarn. However, the evenness obtained in this manner by the back doubling process is
possible only up to the circumference of the rotor and the sliver unevenness that is present in the feed sliver
which is more than the rotor circumference is faithfully reproduced in the yarn (with the attendant draft).
Suction pressure is required from feed tube end to facilitate removal of fibres from the feed tube and
accordingly, from the rotor side, air is sucked from the opener roller region through the feed tube. Due to the
centrifugal force and air stream, the fibres leave the opening roller surface and move into the feed channel (F).
Through suction channel (H), the rotor housing (I) is kept under vacuum. The air drowns through the feed
channel at high speed carries and directs the fibres. The rotor assembly needs to be hermetically sealed (i.e. there
should be no suction of air from unwanted regions The feed channel inside of the rotor (K) which rotates at
high speeds (45000 to 120000rpm). The surface speed of the rotor wall must be considerably higher than the
speed of incoming fibres, so that fibres are laid on the rotor wall in a longitudinal - lengthwise form. Now the
free end of the yarn is withdrawn by a pair of take-up rollers. As the yarn is withdrawn, newly arriving fibres get
twisted by the brush like open structure of the open-end yarn and continuous spinning takes place.

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The fibres are then deposited on the interior rotor wall and slide into a groove to form a fibre ring. The yarn
end (L) extends into the rotor groove, where fibres are continuously twisted and formed into the yarn, the draw
off roller (M), assisted by top roller (N) m pulls the finished yarn from the rotor groove, through nozzle and
delivery tube (O).
The yarn moves over the yarn tension bar (P) and the thread guide (Q) to the package (R). The package is
driven at its circumference by the winding roller (S). The thread (Q) performs a traversing movement,
corresponding to the width of the package, so that the yarn is wound with the desired winding helix.
Each revolution of the rotor generates one turn of twist (assuming there is no slip between the open-end and
the rotor).When the open-end yarn has reached its maximum level of twist - the open end yarn begins to roll on
its own axis (yarn‘s own axis). The rotating (spinning) open-end starts grabbing (grasping) the fibres and starts
twisting them to make the new yarn portion continuously. The region in which the open-end grasps and binds
and forms a new yarn is called ―binding-in zone‖. This binding-in zone extends to a certain length which is of
the order of a few mm. The length of binding in zone is a critical factor in obtaining the ―continuous‖ twist.
The withdrawn yarn is wound onto a package driven by a drum. The package winding system is propeller
type. A propeller moves back and forth along the traverse length to produce a random winded package on a
cone. The yarn content per package is usually 2 to 3.5 kg (up to 5 kg). Rotor yarn has a big advantage over the
ring yarn that very long lengths of yarns are free from knots. Yarn waxing can also be done during the winding
in the rotor machine itself.
There is a robot system which does all the locating of defect, and fixing it. This highly technological robot
finds and ties if a yarn is broken at any point of the machine. If it can not fix it will signal the operator to do the
necessary operation. The machine has automatic cone feeding and full cone removal method to.
Fig. 10.6: rotor machine with robotFig. 10.5: front side of rotor

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10.4 Problem and Recommendation
Over the month we staid in the spinning department we have not seen the Rotor machine working. The
reason had been that a fuse was damaged and it could not be repaired. And they had to import that fuse from
there Reiter Company.
This shows wrong inventory control system. Extra vital components of the machine should be purchased
before the machine stops because that particular part is not accessible.
To solve this problem a proper inventory control system should be there. V.E.D analysis can be used in such
conditions. V.E.D analysis is based on the maintenance importance of items which are used for maintenance
purpose. V.E.D is an acronym for V- Vital items with out which the machinery could not function. The switch
board which was damaged can be an example for it. E- Stands for essential items. These items are very
important but missing of them does not cause sudden stoppage but after a certain period of time, it leads to a
serious damage to different parts. D is for desirable items that do not affect operation of the machine but it
would be easier if they were there.
From the above it can be understood to which group of items the inventory control system foucus more
should. Moreover the maintenance department should sort the machine parts into these three groups and
watchfully prepare orders and establish continuous follow up of delivery of item under order.

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Fig 10.7) Block diagram of Spinning department

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B) KNITTING
2.1 Introduction
Knitting is a method of constructing fabric by interloping series of loops of one or more yarns.
Interlooping consists of forming yarn(s) into loops, each of which is typically only released after a succeeding
loop has been formed and intermeshed with it so that a secure ground loop structure is achieved. The loops are
also held together by the yarn passing from one to the next. Knitting is the most common method of
interlooping and is second only to weaving as a method of manufacturing textile products.
Ayka knitting department employ weft knitting machines. When the needles are fixed or are caused to act
collectively, yarn feeding and loop formation will occur at each needle in succession across the needle bed
during the same knitting cycle. All, or a number of, the needles are supplied in turn with the same weft yarn
during the same knitting cycle so that the yarn path (in the form of a course length) will follow a course of the
fabric passing through each needle loop knitted from it.
All the machineries are Circular knitting machines. And there are 81 different kinds of this machines
operating. Their basic structure is the same. The only difference is the Gauge number and Diameter
combination of each machine.
Different kinds of fabric are produced. Single Jersey structure like plane and double jersey structure like rib is
dominant. Interlock structure is produced sometimes. On the plane structure multicolour horizontal stripping is
done by careful arrangement of the feed yarns so that it will yield the required stripping design.
The Raw Material for Knitting Dependent is Cone form both Spinning department and Dyeing department ,
Chemical fibres like elastospan (lycra) from India, and special Viscose yarn which is waxed for Knitting purpose.
We can divide the machines with the following criteria:-
Classification by Diameter
The most important classification parameter for circular knitting machines is their diameter. According to
the machine diameter, we can divide the machines into two main categories:
1. Large-diameter circular knitting machines (from 24 to 40 inches)
2. Medium-diameter circular knitting machines (from 8 to 22 inches)
Fig 1 A) Types of Horizontal stripping B) Multicolour
feed

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Large-diameter machines are mostly designed for manufacturing tubular fabrics while a more restricted
number of large-diameter machines are used to manufacture fabrics similar to those manufactured with flat
knitting machines. Medium-diameter machines are designed for the production body-size tubular fabrics, as
well as fabrics with welt and separation thread, ideal for the underwear market.
Classification by Number of Needle-beds
Another classification parameter for circular knitting machines is the number of needle-beds, which determines
the type of stitch that can be carried out:
1. Single-bed circular knitting machines (for jersey and derived stitches: fleece, terry, piquet, floating Jacquard)
2. Double-bed circular knitting machines
All double bed machines are Dial-cylinder knitting machines with 90° needle-beds (for rib knit and similar
and Jacquard stitches, as well as all interlock, e.g. the pin tuck stitch) in the department.
2.2 Basic Structure Circular Knitting Machine
Circular knitting machines include a number of fundamental elements, based on similar mechanical principles
with some small changes according to the different models:
 The ―core‖ of the machine, which includes the needle-bed area and all the systems operating during the
knitting process. The feed systems are placed along the circumference of the circular needle-bed. In the
knitting department all the machines are revolving needle bed type.
 The yarn feeding system, made up by the yarn feeding unit which must ensure a smooth and steady yarn
feeding, and a thread guide system which provides the needles with the yarn necessary for the stitch
formation.
 The fabric take-down and winding system housed in the lower part of the machine; depending on the
machine model, the fabric take-down and winding motion can rotate together with the needle-beds or
stand still.
 The drive, an inverter drive, i.e. a motor with electronic variation of speed for optimum acceleration and
slow-down ramps and optimum throughput speed in all conditions.
2.2.1 The Yarn Holding System
The spools of yarn to be used to manufacture the fabric are arranged on a holder is the lateral creel type
which is fixed on the floor beside the machine. The lateral creel is a metal structure positioned on both sides of
the machine. The yarn threads are unwound from the spools positioned on the creel pegs. After having passed
through special pneumatic guides which pushes the yarn
through Aluminium tubes using air pressure, then yarns
reach the thread guides on the machine. In this case, too, the
yarn path is monitored by sensors which detect possible
breaks and knots. The lateral creel facilitates the operation
when changing the spools or in the case of yarn breaks, and
allows a reduction of dust and flying particles in the knitting
room because the guide tubes connected with an automatic
suction system. It can accommodate a huge number of
spools. This allows the possibility of double thread feeding
to each feed system.
Fig 2 Lateral type of creel

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2.2.2 Yarn Feeders
The motorized yarn accumulator levels off the yarn tension since when rotating, it accumulates a certain
quantity of yarn on a constant-diameter pulley and then stops. The yarn wound on the accumulator is then
conveyed to the thread guide always maintaining the same tension. The machine takes up the yarn, gradually
emptying the accumulator, which is then restarted automatically to replenish its yarn reserve.
Some knit structures need elastic material for fitting purpose. There is a device which also rotates with the
speed of the positive device for proper synchronization of feed. But there is no positive feed device for it. This
is necessary when the same type of feeding technique cannot to be applied to all the feed systems due to the
structure of the knit stitches. Therefore, yarn accumulators are mainly used on machines for the manufacturing
of fabrics of pre-set length, or also of continuous cloths with Jacquard patterns.
Since there are many kinds of machines they use different kinds of positive feed device. But all have the
same function and operation. The feeding pulleys with 2 or more levels are useful when changing knitting
constriction being able to select more tape speed. The lower pulley has a function of positive yarn feeding and
used in jacquard selection and the lower pulley is storage type and is used for knitting plain jersey fabric.
Positive feed systems control the tensions of the yarn fed by means of a drive wheel or a drive belt system.
The drive wheel systems, which in the past were much more widespread than today, consist of two conical
toothed wheels. The thread passes between the two wheels and the quantity of yarn can be adjusted by
approaching or withdrawing the wheels. This positive system grants a smooth feeding of the yarn on all the feed
systems. The belt makes the spool rotate, and the number of rotating spools corresponds to the number of feed
systems. By adjusting the belt RPM, the quantity of thread can be increased or reduced. This system grants an
accurate control of the yarn tension
Fig 3 Type of yarn feeders (Positive feed devices) A) Mfd/4 type B) Mpf 20L type C) Mpf 30L type D) Iro type
A B C D
Fig 4 Speed adjustment pulley for positive feed device

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2.2.3 The Thread Guide
The tread guide is the fundamental element of a yarn feeder. On circular knitting machines each thread guide
corresponds to a feed system. The thread guide is a steel or ceramic plate with a hole for the thread. The thread
guide is positioned near the hook of the needle and, besides feeding the yarn; it opens and protects the latches.
The thread guides of double-bed machines feature two holes: one is used for conveying the yarn to the needle
on the cylinder while the other hole only serves for feeding the dial needles when these are working.
Some machines have more thread guides for the same feed system, e.g. the circular knitting machines for
continuous striped jersey or those equipped with Jacquard selection systems. The whole set of thread guides
mounted on these particular machine models is called stripe pattern motion (Fig A). Stripe pattern motions
usually include four to six threading-in options and a yarn retaining/cutting device. A gripper is positioned
between one thread guide and the next to keep the threading-in position while changing the color on the stripe
pattern motion. The machine head controls the gripper which holds the thread while the scissors cut the thread
as soon as it stops.
The yarn remains threaded-in the thread guide, held by the gripper. The thread is released from the gripper
and fed to the needles only when the thread guide is activated again. Thanks to a centralized programming
system, the different thread guides are only operated when necessary depending on the color or yarn change.
Special thread guides with double threading-in are used for generating special patterns, for example plating.
Together with the thread guides operating in the stitch formation position, special additional thread guides are
employed for feeding the weft yarns.
2.3 Stitch Formation Motions
Circular knitting machines, both the single or double-bed types according to our initial classification, can
incorporate various stitch formation motions depending on the machine‘s technical features.
Single-bed Machines:- Single-bed circular knitting machines are equipped with only one series of needles
sliding in the grooves of a circular needle-bed. The needles are latch needles. The cams, which drive the
movement of the needle forming the stitch, are placed outside the needle-bed; each feed system is provided
with its own cam group.
All the cams are fixed to a bearing structure called ―cam frame‖. The cam frame is stationary, while the
needle-bed revolves. Outside the cams, on each feed system, there are special micrometric screws, which adjust
the stroke of the lowering cams and determine accurately the length of the yarn fed.
The cams are screwed to the cam frame and command a single movement of the needle: for example, when
for a certain feed system we only have one group of lowering and rising cams, the selection possibilities will be
very restricted. In fact, in this feed system, the needles must knit or remain idle (this is the typical situation of
Fig 5 Thread guide types A)Stripe pattern motion B) single jersey C) electronic Jacquard needle
selection
A B C

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jersey knitting machines). In this case, to modify the pattern it is necessary to change the cam. These technical
limits have been overcome by increasing the number of needle butts and the corresponding cam tracks
necessary to drive the needle. Some of the single-bed machines have up to 5 selection tracks.
Single-bed machines must also incorporate sinkers to carry out the knitting cycle: the sinkers hold the fabric
already formed while the needles rise for the next stitch formation cycle. The sinkers also support the fabric
when the previous course is knocked-over. Sinkers are driven by special cams whose shape depends on the type
of the sinker itself.
Double-bed Machines:- Double-bed circular knitting machine are equipped with
two series of needles: one series of needles fits in the circular needle-bed, called ―cylinder‖, while the other
series is accommodated inside radial grooves positioned at 90° with respect to the cylinder, on a special circular
plate called ―dial‖. Double-bed circular knitting machines usually incorporate latch needles, but some
manufacturers also offer machines equipped with compound needles. The cams that command the various
needles are fastened to two cam frames, one around the cylinder and the other above the dial.
Fig 6 Different needle cam profiles and needle
selection
Fig 7 Different Sinker cam
profiles
Fig 8 Double (left) and Single ( right) Needle
bed Profiles

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Stitch Formation with a Latch Needle
1. At the beginning of the process, the needle is positioned on the knock-over plane with the loop thread
inside the hook, closed by the latch.
2. The upstroke motion of the needle makes the thread slip downward
touching the latch; this makes the latch rotate anticlockwise and open
the hook. Once the needle has reached its maximum height on the
looping plane, the latch opens wide and the stitch moves along the
stem.
3. The needle now begins to move downward. On reaching the tuck-
stitching plane, it catches a new loop thread.
4. In the further down stroke of the needle the stitch already formed
touches the latch, making it rotate clockwise. As the needle continues
its downward motion, this stitch begins closing the latch on the hook.
5. The needle reaches the end of its stroke (i.e. its lower point) and the
previous stitch, after having closed the hook completely, is knocked over on the new loop forming a new stitch.
Selection by means of Needles with Multilevel Butts
The most common selection system for the creation of plain (or simple operated) patterns on single and double
bed machines, are the needles provided with multilevel butts matching the corresponding cam tracks to carry
out the knitting cycle. The operating principle is quite simple: when the needle reaches a specific knitting level, it
generates a knit stitch, a tuck stitch or a miss stitch according to the type of cam sliding in the track
corresponding to the specific needle butt level. Single bed machines can incorporate needles with up to 4 to 5
butt levels for as many cam racks, while on double bed machines, cylinder needles have 4-level butts and dial
needles 2- level butts. The reduced number of tracks on the dial is determined by the fact that the dial has a
fixed diameter; therefore the grooves cannot exceed a certain length, with the result that dial needles are
relatively shorter. This is done by all machines in the knitting department.
Electronic Jacquard Selection System
The precise definition of this needle selection system for circular knitting machines
is ―electromechanical selection with electronic control‖, based on the use of
piezoelectric actuators that act on the selectors, or of a magnet which commands a
striker placed under the needle. If the selection is carried out with a single magnet,
when the magnet is excited the striker assumes a vertical position thanks to the
action of a control spring, then reaches the rising cam and forces the needle in the
working position. When the magnet is not excited, the spring withdraws the striker
into the groove in the non-knitting position together with the corresponding
needle.
The ―needle-by-needle‖ selection allows the knitting of design patterns of almost
unlimited size since each needle can be independently set in the knit, tuck or miss
position. The electronic selection is now widely used for the needles of the cylinder, while on several double-bed
knitting machines; the selection of dial needles is still carried out mechanically with cams and tracks. This can be
found on Orizio model J8be machines.
Cylinder stitch length adjusting mechanism with stitch adjustment screw has
built into each cylinder and cam holder section on each yarn feeder,. By turning
this stitch adjustment screw to the right or left directions, the cylinder cam can be

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shifted higher or lower, and as consequence stitch draw amount (Stitch density) on the side can be adjusted
tighter or looser.
2.4 Take-down and Winding Motions
The fabric take-down and winding motions have been designed to facilitate stitch knock-over and fabric
take-down procedures. The take-down and winding functions are kept separated in order to allow a smooth
running of the machine and avoid possible fabric distortions.
2.4.1 Take-down Motion
The take-down motion consists of 2 or 3 rollers placed beneath the cylinder. In the simplest system
configuration (i.e. the two-roller) the fabric passes between two rollers that stretch it by rotating in opposite
directions. The best system is a motorized three-roller take-down motion which pulls the fabric without slipping
and without exerting too much pressure that could damage the fabric.
Circular knitting machines pose some problems as regards the winding of the fabric, as the fabric itself is
delivered in tubular form and must be spread flat prior to
winding. The spreading of the tubular fabric generates
some distortions because of the different distances
between the various zones of the tubular fabric emerging
from the take-down system and the same zones wound
on the fabric roll. These differences reflect into uneven
winding tensions (the tension is lower in the fabric centre
and higher at its edges). To avoid these problems, a metal
frame called ―spreader‖ has been incorporated before the
fabric winding system. The spreader increases the width
of the tubular fabric by giving it an almost circular shape,
equalizing the distances between the various zones of the
fabric and the nip line of the winding system
2.4.2 Winding Motion
The fabric winding motion is provided with a clutch. In this way, to
grant a steady peripheral speed, the angular speed of the winding roller can
be gradually reduced as the diameter of the fabric roll increases.
Some machines feature an ―open‖ base that allows the fabric cutting and
opening on only one side prior to winding. In order to allow the take-up of
the open fabric, the width of the winding roller must be twice the width of
a standard one.
The take-up step is carried out on the already opened fabric, and the
edges of the fabric are kept tensioned by means of two rollers with worm-
screw profiles. This avoids the problem of central marks which is
particularly serious on elastic fibres.
Fig 9 take up and winding motion with
fabric spreader
Fig 10 Clutch connection between
the wind and take down rollers
Fig 11 Open width winding
motion

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2.5 Quality control
Ayka Knitting department produces fabrics based on its customers demand. A list of values of the demanded
with a sample of it is sent to this department. This list includes list of values for Stitch density, Weight per
square meter, Width off machine, Standard piece weight, and Fault allowance.
After deciding the specifications the machine is set up, to the specifications and an initial fabric has been
tested and found to be satisfactory, quality control personals carry out inspection and testing procedures as per
schedule fixed. Inspection of yarn on machine will include correct yarn and color being creeled, proper
threading through stop motions and guide eyes, quality of knots, cone damage, and bad winding etc. Knitting
head inspection will include proper setting of positive feed drive and its speed being synchronized in relation to
the machine speed; correct tensioning of the yarn etc. When using a positive feed tape system, it is very
important to maintain even tensions before the yarn enters the tape wheels. There should be no Slippage
between the tape and the feed wheel. Inspection of the fabric takes place in every hour.
To assure quality production, there is a continuous on-the-spot inspection of the cloth as it comes off the
machine. Every machine is equipped with a light around the fabric take up to facilitate this. There is also post-
inspection of the fabric rolls, after doffing, is carried out. It is possible that a knitter may miss faults during on-
the-spot inspection because of the difficulty in focusing on revolving fabrics. By post-Inspection process, the
adverse trends can be seen and reported to the appropriate authority before further pieces are knitted.
Post inspection examination of fabric includes feeding the fabric over a lighted screen specially prepared for
quality inspection. The operator stands far enough back from the fabric to observe all the examining area
without undue eye or head movement. The speed of the fabric passing the viewing point is also of vital
importance. Normally, ten to twelve meters per minute is suitable speed for single colored fabrics. Whenever
there is a defect the operator starts a counter on the machine until the defect stops. If it is more than 10meters it
will be cut off. A list is provided to list all the defects that have been observed and the number of that defect is
noted down. This list includes
Machine number
Operator‘s name
Yarn type
And the frequency of occurrence of
defects like
small holes
single vertical line
double vertical line
big hole
very large hole
oil stains
irregular vertical holes
horizontal lines
Fig 12 Quality control inspection
machine

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1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
17 18 19 20 21 22 23 24
32 31 30 29 28 27 26 25
33 34 35 36 37 38 39 40
48 47 46 45 44 43 42 41
49 50 51 52 53 54 55 56
64 63 62 61 60 59 58 57
65 66 67 68 69 70 71 72
80 79 78 77 76 75 74 73
81
Fig 13 Block Diagram of Knitting Department

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Mc
no
Machine Name and
Model
Type of
Needle Bed
Gauge No
English Count
Diameter
in Inches
Take down
Mechanism
01 Pilotelli, jvce-3 Single E 28 34 Open
03 Mayer & Cie, Relant 3 Single E 28 34 Open
08 Monarch Single E 28 34
16 Monarch, v-nyrd Single E 28 32
34 Wellknit, ws-3.ofpf-l Single E 28 30
38 Tarrot, s296 Single E 28 32
42 Jumerca, svr Single E 20 30

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*Machines with Jacquard Needle Selection Open
As there are different machines each have different needle structure to fit, Table 2 shows machines and their
corresponding needle and sinker types.
45 Jumerca, svr Double E 20 30
46 Orizio, jsvrn Double E 20 30 Open
57 Jumberca, sje-2l* Double E 20 30
58 Monarch Double E 20 30
59 Monarch Double E 20 30 Open
60 Orizio, j8be* Double E 20 30 Open
64 Mayer & Cie, Relant 3 Double E 20 30 Open
65 Mayer & Cie, Relant 3 Double E 18 34
66 Monarch, v-nyrd Double E 24 30
67 Monarch, v-nyrd Double E 24 30 Open
68 Orizio, j8be Double E 20 30 Open
69 Orizio, j8be Double E 22 30
73 Orizio, j8be* Double E 20 30
76 Fukahama, sh-bir2 Double E 18 31
77 Fukahama, sh-bir2 Double E 18 34
Table 1 Machine in Knitting Department

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Table 2 Needle and Sinker of different machines
Machine Name Needle Type Sinker Type
Mayer & Cie
Tarrot
Orizio m
Pilotelli M
Monarch
Wellknit

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The sinker is the second primary knitting element (the needle being the first). It is a thin metal plate with an
individual or a collective action operating approximately at right angles from the hook side of the needle bed,
between adjacent needles. It may perform one or more of the following functions; dependent upon the
machine‘s knitting action and consequent sinker shape and movement. The function of sinkers on circular
knitting machine is to hold down the old loops at a lower level on the needle stems than the new loops that are
being formed, and to prevent the old loops from being lifted as the needles rise to clear them from their hooks.
The holding-down sinkers have a rectangular gap cut into their upper surface, far from the nose, into which the
sinker cam race fits, to positively control the sinker‘s movement. Holding-down sinkers enable tighter structures
with improved appearance to be obtained, the minimum draw-off tension is reduced, higher knitting speeds are
possible and knitting can be commenced on empty needles. Holding-down sinkers are often unnecessary when
knitting with two needle bed machines as the second bed restrains the fabric loops whilst the other set of
needles moves.
2.6 Problem Observed and Recommendation
When ever there is a defect occurring on the fabric all the measures taken were checking all the needles and
sinkers. This wastes production time. Even some machines are forced to stop because the problems are not
broken needles or sinkers. So here is list of common problems and their possible causes, with their
corresponding pictures.
Needle Defects
Defects due to needles are as under:
 Broken hook and broken butt- which appear as a ladder in the
fabric and are called ladder defect.
 Broken latch- accumulation of loops and finally breaks the
hooks and appears as long rib in the fabric.
 Bent latch -appear as a line of drops or holes in the fabric.
 Chipped spoon – appear as a fizzy line in the fabric.
 bent hook - appears as a line of drops or holes in the fabric
 Tight needle- improper loop formation and missed loop.
Barre Defects
This defect is reflected as horizontal bars. The main cause of this are;
 Variation in stitch cam setting
 Unequal setting of knock-over depth on the dial and cylinder
at different feeders.
 Slippage in the fabric take-down rollers
 Chipped bearing and belt slippage
 Variation in take down tension
Uneven Fabric Take-down Tension

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Variation in fabric take-down tension will cause bow effect in the fabric. Despite the very complicated take
down mechanism of the machines there is problem in the setting of the tensioning device which cause problems
of tiring up fabric as shown in the figure.
Gatting of Needles
The gatting of needles is to properly set in the case of rib and
interlock machines. Otherwise defects like loop bursting and missing
of loops will occur in the fabric.
General list of Solutions
Fabrics defects on latch needle sinker top jersey machine and their probable causes:
A. Vertical lines : i) bent needles, ii) worn needles, iii) wrong needle, i.e. needle size not appropriate with the
cut of the machine, iv) dirt in trick slots, v) defective or worn-out trick walls, vi) bent hooks, vii) chipped
latches, butts or broken spoons, viii) stiff sinkers or stiff needles viiii) sinkers ride high because of dirt
B. Horizontal lines: (i) Uneven yarn, (ii) uneven yarn tension, (iii) Uneven stitch length, (iv)uneven take-
down tension, (v) mixed yams, (vi) loose stitch cams, (vii) uneven twist in yarn, (viii) poor winding from
cones, etc.
C. Holes and cuttings: (i) weak yarn, (ii) yarns with bad knots and slubs, (iii) lint in yarn guide or eye-pots,
(iv) stitch drawn too tight, (v) stiff latch, (vi) unsuitable yam number, (vii) machine running too fast, (viii)
rough sinkers, (ix) carriers set wrong (x) take-down mechanism too tight (xi) misaligned cones, (xii)
needles too tight in their slots, etc.
D. Distorted stitches: (i) bad or bent needles, (ii) incorrect positive feed setting, (ii).uneven yam tension, (iv)
bent trick walls, (v) needle timing wrong, (vi) improper stitch cam settings, etc.
E. Press-off: When an end of yarn breaks out the needle will knock over its previous loop without forming a
new stitch. This is called an ‗end out‘ .If this end out occurs in succession on a number of needles, it is
called a 'drop out' or a 'press off'. The main causes of press off are (i) faulty stop motion, (ii) plugged yarn
guide with lint. (iii) bad Yarn, (iv) machine running fast, (v) bad knots and slubs etc
Fabric defects on Rib, interlock and Double-knit machine
A. Vertical lines: (i) Dirty needles and slots,(ii) faulty needles, (iii) gaiting off centre for dial and cylinder
(iv) cylinder and dial height not properly set, and all other causes which are listed in the case of single
jersey fabrics.
B. Horizontal lines: All causes mentioned earlier for single jersey fabrics, and dial not horizontal, dial or
cylinder becoming oval-shaped, stitch cam settings for dial and cylinder, not equal and timing out of
sequence.
C. Holes and cuttings: All causes mentioned earlier for single jersey fabrics, and thread guides not
allowing dial latches to open, thread guides too near needles, positive feed system operating improperly,
excessive tension, dial height too low or high, yarn threaded wrongly, gaiting not correct etc.
D. Drop-stitches: Besides the causes mentioned for this defect in single jersey, the following are the
additional causes: (i) dial latch closing under yarn carrier (ii) dial height too high, (ill) fabric too loose, (iv)
positive feed slippage, (v) yarn in wrong hole of carrier, etc.

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E. Unwanted tuck stitches: (i)" dial stitch-cams not pulled in far enough, (ii) yarn too coarse, (iii) yarn too
dry, (iv) take-up roller slipping, (v) needle latches, (vi) stiff latches, (vii) loose rivets (viii) opened-out
hooks, (ix) worn hooks; (x) height set too low, (xi) defective needles, (xii),needles move too freely in
their slots etc.
C)Dyeing Finishing &
Printing

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Table 1.1 Dye types
C) Dyeing Finishing & Printing
1.1 Introduction
Dyeing is a process of applying colour to fabrics or yarn. The sensation of colour is produced when light
having a wavelength within the visible region of electromagnetic spectrum strikes the retina of eye. When light
passes through matter or is reflected from it, some of the light may be absorbed. The energy of light is
transformed into energy of motion of molecules; or electrons in the molecules may be promoted to higher
energy levels. If a substance absorbs all visible light except one band, which it reflects, the substance will have
the colour of that reflected band.
Dyes are normally water-soluble or water dispersible organic compounds that are capable of being
absorbed into the substrate destroying the crystal structure of the substance. The dye molecules are usually
chemically bonded to the surface and become a part of the material on which it is applied. To be of
commercial interest, dyes must have high colour intensity and produce dyeing of some permanence. The
colour intensity of the dye molecule depends on how strongly it absorbs radiation in the visible region, which
extends from 400 to 700 nm.
The process of dye application involves the transfer of dye from a solution in a dye bath to the fibre; the
dye preferentially adsorbs onto and diffuses into the fibre. In order for a dye to move from the aqueous dye
bath to the fibre phase the combination of dye and fibre must be at a lower energy level than dye and water.
This may be achieved by the proper selection of dye for the particular fibre type.
Classification of Dyes
To act as a dye, certain conditions must be fulfilled:

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1. It must have at suitable colour.
2. It must be able to ‗fix‘ itself or be capable of being fixed the fabric.
3. The fixed dye must have fastness properties:
(a) Fastness to light or resistance to light
(b) Resistance to the action of water, dilute acids and alkalis various organic solvents used in dry cleaning
Ways in which the dye molecule may be bound to the fibre:
(I) Covalent bonds;
(II) Hydrogen bonds;
(III) Ionic bonds;
(IV) Van Der Waals forces.
The type of binding for a given dye will thus depend largely on the chemical nature of the fiber.
1.2 Cotton Dyeing
The cotton fibers are hydrophilic and swell in water. It is hydrolyzed by hot acid and swollen by
concentrated alkali. The cotton is treated with caustic soda solution (12-25 %) under tension to develop a silk-
luster and stop longitudinal shrinkage. This process is called mercerization. Mercerized cotton exhibits
increased moisture and dye absorption. The dyeing of cotton fiber is accomplished by three principal
processes. Cotton may Cotton may be chemically reacted with fiber-reactive dyes in solution.
The dyeing take place by reaction with hydroxyl groups in cotton. A second method is the use of
substantive dyes which diffuse directly into fiber from a dye solution. The dyeing rate is increased by the
addition of electrolytes. The third method is referred to as mordant dyeing in which the dye in solution reacts
with metals previously applied to the fiber to form insoluble colored compounds on the cotton.
Vat dyes are another important class of dyes for cotton. These are applied in a soluble reduced form
and after application they are oxidized, forming an insoluble molecule.
THE APPLICATION OF DYES
The basic operations of dyeing remain the same and include the following:
a) Preparation of the fiber
b) Preparation of the dye bath
c) Application of the dye
d) Finishing
The textile material generally needs a pretreatment before dyeing. Cotton must be boiled and bleached to
remove pectins and cotton seeds and is mercerized. Sizes and spinning oils must be eliminated. The dyeing of
fiber from an aqueous dye bath depends on the dye-fiber interaction. Depending on the nature of dye and the
nature of fiber, the dye is fixed on to the fiber chemically or physically.
Additives such as wetting agents, salts, carriers, retarders and others may be added to the dye bath along
with the dye if required to facilitate the dyeing process. This are referred to the organic cyclic type compounds
used for the manufacture of synthetic dyes.
In machine dyeing, the yarn or cloth is moved in the dye bath, which is kept stationary except for the
agitation of the liquor due to the movement of the yarn or cloth

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1.2 Dyeing Procedures
Fabric dyeing process depends on the fabric type. Meaning chemicals and different dye stuff which are
used in every process vary with the fabric physical and chemical properties. So as an example we take three
types of fabric and process flow diagrams that took place in Ayka Dyeing department. The fabric form
knitting departement will be examined for defects again by moving it in front of florescent screen and only if
it passes that it will be dyed.
1.2.1 Bleaching
Bleaching is the first step is fabric dyeing, Natural fibers, i.e. cotton, wool, linen etc are off-white in color
due to color bodies present in the fiber. The degree of off-whiteness varies from batch-to-batch.
Bleaching therefore can be defined as the destruction of these color bodies. White is also an important market
color so the whitest white has commercial value. Yellow is a component of derived shades. For example, when
yellow is mixed with blue, the shade turns green. A consistent white base fabric has real value when dyeing light
to medium shades because it is much easier to reproduce shade matches on a consistent white background than
on one that varies in amount of yellow. And most fabric impurities are removed.
Other chemicals will be used in addition to the bleaching agent. These serve various functions such as to
activate the bleaching system, to stabilize or control the rate of activation, to give wetting and detergent action.
The sequence of application of bleaching is as follows.
1.Before the bleaching agent is applied the machine is cleaned, there is at least 3 cycles of draining the
machine and filling it with water.
2.Then the bleaching chemicals are added. Here all the chemicals are not added at the same time
Oil remover- to remove oil contents of the fabric, specially since cotton has oil by nature
Heptol- used as a bleaching agent, to bleach the fabric
Caustic Soda- to remove impurities and as additional bleaching agent. By the end of its action it
will change to soap by soponification process.
3.Addition of Hydrogen Peroxide which is the main bleaching agent chemicals used to bleach large
proportion of fabric. Hydrogen peroxide is a weak acid and ionizes in water to form a hydrogen ion. The
perhydroxyl ion is the active bleaching agent.
4. Sodium tio sulfate (antiper)- is used to adjust the concentration of hydrogen peroxide. Hydrogen
peroxide is an extremely weak acid, Ka = 1.5 X 1012. Since the perhydroxyl ion is the desired bleaching
specie, adding caustic neutralizes the proton and shifts the reaction to the right. Therefore: 1. at pH < 10,
hydrogen peroxide is the major specie so it is inactive as a bleach. 2. At pH 10 to 11, there is a moderate
concentration of perhydroxyl ions. pH 10.2 to 10.7 is optimum for controlled bleaching. Sodium tio sulfate is
used to obtain the proper pH. 3. At pH > 11, there is a rapid generation of perhydroxyl ions. When the pH
reaches 11.8, all of the hydrogen peroxide is converted to perhydroxyl ions and bleaching is out of control.
Acitic acid (Acetic asit) is also used for ph adjustment.
5. Addition of Nova cell A96(T02) enzyme- during the bleaching process oxidized remains remain on
the surface of he fabric. They becomes hard deposits which build-up in the machines causing the fabric to
be abraded. Also some of the deposits will form in the cloth, giving it a harsh, raspy hand. So we use the
chemical to remove hair for large composition of cotton fabric.
Stabilized hydrogen peroxide does not decompose at high temperature there for faster and better bleaching
occurs at 95 to 100 0C. This feature makes it ideal for continuous operations using insulated J-boxes or open-
width steamers.
Chemical 1 Chemical 2
80-95c for 20mins
80c for 10 mins
80c for 10 mins

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1.2.2 Dyeing
The second step is application of colorant or dye fixing. A typical flow is as follows
1) A single fill and drain step is performed in order to remove the bleaching stuff in the machine
2) Then there will be a temperature adjustment. As different fabrics need different amounts of temperature
to apply the dye stuff. For example cotton dyes like Evercion and Everzole need relatively cold
temperature (60c ) for application. Some cotton dyes need up to 80c (hot temperature dyes). Synthetic
fabrics like Polyester fabric dyes need 130c. During processing of cotton/ polyester blends first we
should add polyester dyes which work at higher temperature than cotton dyes because cotton dyes will
be damaged at high temperature.
3) During dye application we should also adjustment PH values. This also varies with the type of fiber
the fabric is made. For example full polyster needs 4-4.5 ph values and Evercion dye needs ph
value of 6-6.5.
4) Dye stuff and some chemicals are dosed at this step
a. Acetic acid for PH adjustement
b. Wetting agent (Boya iyontutuch)- The ability of a liquid to spread on a smooth solid surface is
dependent on the polar nature of the solid and the surface tension of the liquid. A non-polar
solid surface such as paraffin wax or Teflon will cause a drop of pure water to bead-up and not
spread. Water containing surfactants on the other hand will easily spread on paraffin surfaces
and have lower contact angles on Teflon. Surfactants used this way are called wetting agents, or
penetrating agents when used to wet out repellent fabrics.
c. Salt (NaCl)- make the fabric ready for dye absorb and act as an electrolyte for color
fixation
d. Soda ash- to fix the dye on the fabric
5) Color sample- shade color check up
1.2.3 Washing
The third step is washing the fabric at high temperature (95c) to remove chemicals and to check the dye
is applied correctly. Before washing the color of the fabric must be slightly ―stronger‖ than the sample so
that after washing it will have the same shade as the standard sample. A number of fill and drain steps are
taken. The washing operation is done with only soap (sometimes with acid).
Color sample and PH check is done at last. Shade color check up is done at last to check the color
applied have the same shade as the required color. This is done by a visually comparing the fabric with a
standard by skilful person.
Chemical
Dye
Soda Soda
Cold
Cold
95c 5‘
80c 5‘
Soap 95c 5‘
Soap
60c 5‘

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Figure 1 Thes Model Dye applicator machines
Figure 2 Thes model yarn dye
Applicator machines
1.2.4 Softening
This is the last step in fabric dyeing. First there will be simple fill and drain. The fabric regains its
properties lost because of the previous processes. Softening works relatively at lower temperature (50c)and
for most fabric type the ph must be around 4.5-5.
Two chemicals are used for softening
Acetic acid for Ph control
Perrustol se1, perrustol IMA RD- TPW, Rucofil TPW (Yumusatma) as a softening agent.
The above procedures will be fed to the machine by using the control panel. In the diagrams above the
line shows the tempraure range, i.e., if the line goes up, it means increase the temperature and if it goes down
decrease the temperature. The horizontal line signifies a constant temperature shown above the line for the
specified time shown above it. The procedures are designed for a specific fabric type and specific dye by a lab
personel.
Below are some machine models of Thes machines with different capacity to hold fabric.
After the fabric is dyed and washed in Thes machines it will be squeezed by
circular machines with moving part in the middle so that the fabric is squished by
appling high centrifugal force.
Yarn is also dyed. Dye is applied by diffusing it through a perforated plastic cone in which the yarn is
wound up from spinning department.
Acid
Perrustol
50c 20‘

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Figure 3 Santex model stenter machine
2 Mechanical finishes
Fabrics whether dyed or only bleached will have Mechanical Finishing procedures if further treatment is
needed. This defined as any operation performed to improve fabric appearance or function by physical
manipulation. Steam or water may accompany the physical manipulation; however, chemicals other than
lubricants are seldom used. Fabric luster, smoothness, softness, residual shrinkage and hand are examples of the
properties that can be altered by mechanical finishing. This include
2.1 Compacting and Shrinkproofing
Controlled residual shrinkage is an important quality parameter for many fabrics. For example, excessive
shrinkage is undesirable for fabrics to be made into garments. Here, the residual shrinkage should be less
otherwise the garment will not fit after it is laundered. Drapes cut to floor length will draw up from the floor
and detract from their appearance unless the residual shrinkage is controlled. Before launching into the
mechanical methods of reducing shrinkage, it will be instructive to discuss the causes of fabric shrinkage.
The degree of crimp is a function of the yarn size and fabric construction. When fabric is completely
relaxed, the crossing yarns will move around in relation to each other until a stable configuration is reached.
This stable arrangement, the point where the relaxed fabric no longer shrinks in width and length, is also related
to yarn sizes and fabric construction. When stretching tensions are applied to the fabric, the crimped amplitude
decreases and the fabric grows in the direction of the stress. Later when the tensions are relieved and the fabric
allowed to relax, the crimp amplitude returns to its stable configuration and the fabric shrinks. Many fabrics are
stretched during wet processing as they are pulled from one operation to another. This is the major cause of
fabric shrinkage. This is done by Santex machine which has a stennter at its front part and dryer disks in its
main body.
2.2 Sanforization
Mechanical compacting is one method of reducing residual shrinkage. The process forces yarns closer
together and the fabric becomes thicker and heavier. As a result of this, the net yardage yield is reduced. The
term Sanforized is now generally accepted to mean a fabric that has low residual shrinkage and the term
Sanforizing is used to describe shrinkproofing processes. The process, consists of a range where the fabric is
first moistened with steam, to make it more pliable, run through a short tenter frame (pup tenter) to straighten
and smooth out wrinkles, through the compressive shrinkage head and then through a Palmer drying unit to set
the fabric. The fabric is wound into large rolls under minimum winding tensions. If the winding tension is
excessive, the fabric will be pulled out and the degree of compaction lessened. Usually, a lubricant is added in
preceding operations to assist in the realignment of the yarns as the fabric runs through the compactor.
Selection of the proper lubricant is critical for some fabrics.

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Figure 4 Mario Costa Raising machine
Figure 4 Bruckner sanfrizing machine(left) and Sanforizing effect(Right)
2.3 Raising
Raising is the term used to describe the creation of a pile surface on a fabric. Fibers are deliberately pulled
part way out of a yarn to give the fabric a hairy or fuzzy appearance and a soft surface texture. Napping, Sueding
and shearing are techniques for developing a surface pile. Raising is used to enhance the appearance and hand of
fabric. It is used not only to improve their hand and appearance but to increase their bulk, to impart the feeling
of warmth, to increase the number of fiber ends on the surface of the fabric, to provide improved adhesion for
laminating purposes and to improve the profit margin per yard sold. Many of the same techniques are used to
knitted goods made from synthetic and synthetic blended fabrics. Sueding and napping machines are used on
both filament and spun constructions while shears, polishers, calendars and decaters are used singly or in
combination to create specific surface effects. Ayka uses Mario Costa model machine for sueding and napping
process which is connected to collecting suck pneumatically to remove dust and raised waste.
2.4 Singeing
The object of singeing is to remove projecting fibers from the
surface of the fabric so as to give it a smoother, cleaner appearance.
The Osthhoff singer machine has two rows of gas burners arranged
so that the material passes rapidly through the open flame. The speed
of the cloth travel is adjusted to burn away the hairs without
scorching the fabric. In a normal sequence of operations, the singed
fabric passes directly into Earbatch Jbox machine that contains a
quench bath that contains the chemicals to douse any fuzz ball that
might have been ignited. The singer is arranged so the fabric is routed

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Figure 5 Reggini model unica Printing machine
around a steel roller at the point where the flame impinges on it. This opens up the fabric to make the
projecting hairs more accessible to the flame. The steel roller absorbs heat from the flame and eventually
becomes hot enough to melt most thermoplastic fibers. The singers are designed so that chilled water passes
through the rolls to keep them cool. While singeing is a simple process, care is taken to not damage the fabric.
The singer is arranged after the printing process for better effect.
3 Printing
Printing is a process for producing a pattern on fabric by any of a large number of printing methods. Printed
fabric is a fabric with designs applied by means of dyes or pigments used on engraved rollers, blocks, or screens.
The color or other treating material, usually in the form of a paste i.e,. a mixture of gum or thickener, dye, and
appropriate chemicals used in printing fabrics, is deposited onto the fabric which is then usually treated with
steam, heat, or chemicals for fixation. Ayka uses Screens to print designs done by using Adobe® Phtoshop CS3
Software.
Roller Screen Printing involves the application of designs to fabric using a combination of roller and screen
printing in which a perforated cylindrical screen is used to apply color. The areas of the screen through which
the coloring matter is not to pass are filled with a waterproof material. The printing paste which contains the
dye is then forced through the untreated portions of the screen onto the fabric below. Each roller is supplied
with one color to the finished design, and as the fabric passes between the roller and a padded cylinder, each
color in the design is applied. Color is forced from the interior of the screen onto the cloth. The machine is
equipped with 16 rollers.
Methods of Producing Printed Fabrics in Ayka:
1. Pigment Printing: Printing by the use of pigments instead of dyes. The pigments do not
penetrate the fiber but are affixed to the surface of the fabric by means of synthetic resins which are cured
after application to make them insoluble. The pigments are insoluble, and application is in the form of
water-in-oil or oil-in-water emulsions of pigment pastes and resins. The colors produced are bright and
generally fat except to crocking. Here a pigment color and a pigment path is used. Pigment printing is
usually used for polyester fabrics.
Pigment pad recipe
1 Binder- to facilitate the reaction of dye to the fabric
2 Fixer- to fix color to the fabric so that it is not washed away
3 Ammonium- to neutralize the ph of the bath

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4 Antifoam-An additive that minimizes the formation of bubbles within or on the surface of a liquid by
reducing the forces that support the bubble‘s structure.
5 Softener- Chemicals that reduces the hardness of water by removing or sequestering the calcium and
magnesium ions. And water as a solvent medium for reactions to take place.
Pigment colors: - red, violet, green yellow, blue, scarlet
The fixation process: - fixing the color by heating it at a particular temperature (150-160c) for 6 mins and
involves no application of washing procedure.
2. Reactive Printing is usually applied for cotton fabrics and its effect can be seen on both parts of the
fabric. It operates by using Sodium alginate and gum prepared separately by sprinkling their dry powder
over cold water under constant stirring and is allowed to stand for few hours to attain full swelling of
the gum particles. 10% solution of sodium bicarbonate is prepared and is added to the printing past just
before printing. The printing paste is prepared by mixing the dye stuff with urea before adding cold
water. The solution is then stirred into thickening and the required amount is added to cold printing
paste. Then the print paste is applied on the fabric.
Reactive pad recipe
1 Sodium bicarbonate:- as a buffering agent
2 Soda
3 Urea
4 Precilon as a thickening agent
5 Sodium alginate and water
Reactive colors –Golden Yellow pr, violet krl, navy 2rn, orange p2r
3. Disperse and Heat Transfer Printing: A method of printing fabric of already dyed fabric, polyester
or other thermoplastic fibers with disperse dyes. The design is transferred from preprinted paper onto
the fabric by contact heat which causes the dye to sublime. Having no affinity for paper, the dyes are
taken up by the fabric. The method is capable of producing well-defined, clear prints.
Disperse pad recipe
1 water
2 citric acid as a buffering agent
3 Rapid print sr6
4 Precilon 58
Disperse colors – dichlorotriazinyl (Brill Red m)
4. Acid Printing:- usually used for Nylon fabric. It has the effect of making the surface rough and has
an embossed 3d effect. Here the acid is applied based on the design and the other part of the fabric with
no design is left.
Acid pad recipe-
1 urea
2 Glycerine
3 Ammonium sulphate
4 Precion DCA580
5 Rapid Print LM

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Figure 5 Salted Model VPM 802011Colour Fixing machine
Sometimes decorative dyes are applied on any type of printing. These dyes can have a sparkling effect or a
sandy effect and are called Devour dyes. The bath includes Ammonium sulfate, Precion DCA580 and Glycerine
After the fabric is printed with the required color it the color is not wash proof. So it should be processed
with wash proof finishing like color fixing processes which uses steam and additive chemicals like sodium
chloride for further processing.
4 Analysis of Water
Water Hardness and Salt content is measured every day before it is applied to dyeing department. Hardness
is generally expressed as equivalent parts per million (p.p.m.) of calcium carbonate irrespective of the actual salt
present. To calculate the hardness of particular water the concentration of actual magnesium or calcium salt is
converted to an equivalent weight of calcium carbonate.
The total hardness of water can be determined either by using standard soap solution or by using EDTA
reagent. After adding a ph indicator tablets, it is added then shaken until it becomes green. Mg+ and Ca+ are
not needed and after the testing it is preferred that there content is zero.
The other thing that is tested is how much the water contains foreign chemicals. The COD (Chemical
Oxygen Demand) testing procedure can tell this. The procedure is as follows.
1. Pipette 5cc of water
2. Add 5cc of chromatograph chemical
3. Add one spoon of N-1k indicator chemical
4. Add 6 drops of N-2k chemical
5. Heat to 120 degrees
6. Allow it to cool in Silica jell
7. Add 1 spoon of N-3k chemical
8. Allow it to settle for 1min
9. Pipette 1.8ml of the pretreated sample
10. Put the sample in Spectroquan machine to measure the sample COD
11. Compare the measured value with the standard
After processing water from all departments i.e. Spinning, Knitting and Dyeing is transported through
ducting to the water treatment area. Here the water is filtered to remove any solid material. Then it is treated
with Sulphuric acid illuminate any vegetable material like cotton lint and also to neutralize the water since water
from the dyeing department is alkaline. The water is then ducted to a room where urea is combined to it. Lastly,
the water moves via ducts to a temporary reservoir so that it is continuously agitated as it is treated with oxygen.
This is done along with application of urea to increase the capacity of water for irrigation purposes since it is
removed to the surrounding at last.

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Conclusion
Ayka Textile & Investment Group is one of the Giant companies not only in Ethiopia but in East Africa. It
processes cotton and man made fibers to make high quality products from yarn to fully fashioned knitted
garment. Most of its products are exported to Germany and Turkey.
It has four major departments; Spinning Department where bales form different sources are processed to
give a yarn of particular count, quality and property; Knitting Department where fabrics of different designs are
made by weft knitting process. Dyeing Department where color and different print designs are applied on the
fabric and different mechanical finishes are done to give different texture, increase bulkiness and final property
of the fabric. And the last department is the Garment where the fabric is changed to cloth.
During my stay I have gathered much information about the practical aspects of what I have learned and
gained so much in terms of improving my practical knowledge. I have seen how machines work, how to operate
them, different paths for material flow, and how and why things are done. It is a Textile student‘s dream to get
inside and see all the machines and processes taking place. The internship program had paved the way to do
that.
I have tried to note some problems and I hope there solution help to increase the efficiency of the factory.

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References
1 Carl Lawrence, PhD, Fundamentals of Spun Yarn Technology, British Textile Technology Group, UK, 2003.
2 Durur, G., Cross Winding of Yarn Packages, Ph.D., University of Leeds, July 2000.
3 Charles Tomasino, PhD. Chemistry & Technology of Fabric Preparation & Finishing, College of Textiles
North Carolina State University, Raleigh, North Carolina, U.S, 1992.
4 Klen, Introduction to Short Staple Spinning, vol I-V, UK, 1989
5 S.r. Kar Makar,PhD, Chemical Technology in the Pre-Treatment Process of Textiles, Hooghly, West Bengal,
(India), April 1999.
6 Textile Dictionary, New York, NY, 2001.
7 Alberto M. Sacchi, Reference Book for Knitting, Milano (Italia), 2002
8 David J. Spenser, Knitting Technology - A Comprehensive Handbook and Practical Guide, 3rd Edition,
Cambridge (England), 2004
9 Different class notes and handouts by P.N.R. Jeevananthan, Mr. Ambachew
10 Machine Manuals

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Appendix
Gearing Diagram of Comber Machine

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Gearing Diagram of Ring Frame

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Gearing Diagram of Roving Frame

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Gearing Diagram of Rotor Machine

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Gearing diagram of Draw Frame

Textile internship program report

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