Preparation of weaving

Preparation of Weaving
Book References:
1. Textiles: Fiber to Fabric by Corbman, Bernard P
2. Weaving Convertion of Yarn to Fabric by Lord, P.R.& Mohamed, M.H.
3. Weaving Calculations by R. Sen Gupta (Publisher: B.D. Taraporevala Sons &
Co. Private Ltd.)
4. Textile sizing by B.C Goswami
5. Sizing materials, methods and machines by M.K Talukder
6. Understanding Textiles for a merchandizer by Shah Alimuzzaman Belal

Weaving Preparation
Topic Includes
Introduction
and history
Flow of
weaving
process
Yarn
Preparation

Introduction to Fabric
Manufacturing
Fabric
From
Yarn
Weaving Knitting Braiding
From
Fiber
Non-
woven

Weaving
Weaving is a method of textile
production in which two distinct
sets of yarns or threads are
interlaced at right angles to form a
fabric or cloth. The longitudinal
threads are called the warp and the
lateral threads are the weft or filling.
Cloth is usually woven on a loom, a
device that holds the warp threads in
place while filling threads are
woven through them.
The way the warp and filling
threads interlace with each other is
called the weave.

Evolution of weaving
• Egyptians made woven fabrics
6000 years ago.
• Chinese made fine fabrics from
silk over 4000 years ago.
• A shedding mechanism was
originally developed in China in
the 3rd century and introduced in
Europe.
• In 12th century, completely
wooden hand looms were used
in England.
• The developments of looms
have taken place during the past
850 years.
Backstrap Loom
Hand Loom

• Hand operated fly shuttle
loom was developed in
1733 by John Kay.
• E.Cartwright invented the
power loom in 1785.
• In the beginning of 18th
century, looms made of
cast iron were operated by
steam power.
• At the end of 18th century
(1895), looms were
developed to run by
electric engine.
Air- jet Loom

Evolution of Automation
R. Miller developed the automatic loom stoppage
system in England in 1796.
In 1894 Northrop developed the automatic weft
replenishment system.

History of Shedding Mechanism
• The first Dobby operated by a punch card was invented by
B.Bouchone in 1725.
• Jacquard shedding mechanism was developed in 1801 by J.M.
Jacquard.
• Keighley dobby was developed by Hattersley and Smith in
1867.
• Rotary dobbies were manufactured in 1990.
Jacquard Shedding Dobby Shedding

Weft Insertion System
 Projectile weft insertion system was
invented in 1924 by an engineer named
Rossman which became commercial in
1953.
 Rapier weft insertion system was
invented in 1898 but the production of
rapier weaving machine started in
1972.
 Air-jet weft insertion system was
invented in 1914 and commercially
used in production after 1980.
 Multiphase weaving system was
invented at the end of 19th century.
Projectile
Rapier Head
Shuttle

Knitting
Knitting is the process of
manufacturing fabric by the
intermeshing of loops of yarns.
When one loop is drawn
through another loop then a
stitch is formed in the vertical
and horizontal direction. Loops
run in the horizontal direction is
called course and in the vertical
direction is called wales.

History of Knitting
• Hand knitting system was invented about 256 B.C.
• In 1589, William Lee first invented the knitting machine.
• At 1769, first knitted fabric was produced by using knitting
machine.
• Circular knitting machine was invented in 1798 in France.

Intertwining or Braiding
The process of interlacing three
or more threads is in such a way
that they cross one another and
are laid together in diagonal
formation is termed as braiding.
At least three sets of yarn are
required to produce fabric by
braiding.

Non-Woven
A nonwoven is a textile structure
produced by the bonding or
interlocking of fibres or both,
accomplished by mechanical,
chemical, thermal or solvent means
and combinations of these. Non-
wovens are flexible, porous
products consisting of one or more
fiber layers. There is no need of
spinning process as non-woven
fabrics are directly produce from
fiber.

Types of Loom
Loom
Single Phase Loom
With Shuttle
Hand
Loom
Power
Loom
Automatic
Loom
With Shuttle
Changer
With Pirn
Changer
Unifill
Boxloader
Rotary Battery
Stack Magazine
Without Shuttle
Projectile
Single
Multiple
Rapier
Rigid
(Single/Double)
Flexible
Jet
Water jet
(Single)
Air Jet
Single Nozzle
Multiple Nozzle
Multiphase Loom
Warp
Wave
Filling
Wave
Circular
Flat

Process Flow of WeavingYarn From Spinning Section
Yarn Dyed Production
Solid Dyed Production
Soft Winding
Yarn Dyeing
Drying and Finishing
Hard Winding
Warp Preparation Weft Preparation
Warping
Ready For Looming
For Shuttle less Loom
Pirn Winding
For Shuttle Loom
Sizing
Drawing-in and Denting Looming
Weaving
Woven Fabric
Send to Finishing or Mending Section

Yarn Preparation for Weaving
Yarn is the basic building block in weaving. The
condition of yarn found from the spinning
machine is not always good enough to be used
directly in weaving process. Package size, yarn
characteristics and other factors make it
necessary to process the yarn again for efficient
weaving. So before starting the manufacturing
of fabric, it is required to prepare the yarn for
weaving which is termed as yarn preparation.

Necessity of Yarn Preparation
 To remove or mitigate yarn fault
 To transfer the yarn from a spinners package to a new package that
will facilitate the weaving.
 To clean the yarn for better appearance and performance.
 To have desired length of yarn in the package.
 For better quality of fabric.
Yarn preparation process includes-
 Winding
 Warping
 Sizing
 Drawing and Denting

Winding
Winding is the major preparation process for yarn
preparation for weaving. Winding is basically the
transfer of yarn from one package to another and
produces a package that is suitable for weaving.
During winding yarn defects is mitigated.
Although winding is mainly occurred in spinning
section, it is done in weaving section for the
preparation of yarn. The process of transferring
yarns from ring, bobbin, hank etc. into a suitable
package is called winding.

Warping
Warping process is only done for warp yarn. The
operation of winding of warp yarns into a common
package is called warping. Warping is done for sizing
of warp yarn. Warping is also done for warp knitting.
Sizing
Sizing is the process of applying the size material in
the warp yarn to improve the weave ability of the yarn
by reducing the friction and formation of static
electricity, increasing the smoothness and elasticity of
yarn.

Drawing-in and Denting
Each and individual threads are
drawing in through the heald wires of
the heald shafts according the drafting
plan of the fabric design. Drawing in
include enterring the warp yarn
through the drop wire and heald eye
of the heald wire.
Denting is the process of drawing the
warp yarns through the dents of the
reed. In this process one, two or more
warp yarns may inter through one
dent of the reed as required for the
weave plan.
Drawing Hook
Denting Hook

Winding
This is a process of transfer yarns from ring,
bobbin, hanks etc. into a convenient form of
package containing considerably long length of
yarn. This simple transfer of yarn from one
package (bobbin) to another large package (cone,
spool, pirn) is called winding. A process of
accumulating yarn on a package to facilitate the
next process is known as winding.
Input - Yarn (spinning bobbins)
Output - Yarn (large cones, tubes, etc.)

Objects/Necessity of Winding
• To transfer yarn from one package to another suitable
package that can be used for weaving purpose such as
for warping or weft insertion.
• To improve the quality of yarn.
• Preparing soft package for yarn dyeing.
• To remove yarn faults from spinning like hairiness,
neps, slubs of foreign matters.
• To get a quality fabric.
• To empty the spinners bobbin so that it can be used
again in spinning section.
• To clean the yarn.
• To improve the efficiency of yarn for next process.
• To lubricate the yarn

Requirements of winding
– The fault level in the yarn must be reduced to an acceptable
level that means yarn fault should be minimum.
– The yarn must not be damaged in any way in the winding
process.
– The yarn must be wound in such a way that the unwinding
will be easy.
– The package size, shape and build must be the most
technologically suitable for the particular end use.
– The package size should be controlled to meet the
particular economic requirements.
– Exact package hardness that means the package should
have correct looseness and tightness.
– Winding condition should be constant.
– Cheap cost of package.

Types of winding
According to density of package-
a) Precision winding b)Non-precision winding
According to the build of the package-
a) Parallel wound package b) Nearly parallel wound
package c)Cross wound package
According to type of package-
a) Cone winding b) Pirn winding c)Flange winding
d) Cheese winding e) Cop winding
According to the methods of drive-
a) Direct drive b)Indirect drive
According to features of automation-
a) Conventional winding b) Modern winding

Precision Winding
When the successive coils of yarn on a package
are laid close together & parallel or nearly
parallel with each other, then it is possible to
produce a very dense package in which
maximum amount of yarn is stored in a given
volume is called precision winding.
Example- Warp beam, Weavers beam.

Feature of precision winding
• Packages are wound with a reciprocating traverse.
• Patterning or ribboning causes damage of package.
• Package contains more yarns.
• Low stability of the package.
• Hard and more compact package.
• Flange may be used.
• Dense package.
• Unwinding process or rate is low and process is
harder.
• The wound coil is arranged parallel or near parallel.
• Package contain maximum amount of yarn.
• Yarn tension is comparatively high.

Non-precision Winding
This type of package consists of single thread
which is laid on the package at appreciable helix
(cross) angle so that the layers cross one another
and give stability to the package & a less dense
but more stable package is produced is called
non-precision winding.
Example- Cone, Cheese.

Feature of non-precision winding
• Only one coil is used to make the package.
• Cross wound coil.
• Low density.
• Yarn tension is comparatively low.
• Minimum yarn is stored.
• Soft and less compact.
• High stability.
• Flange is not necessary.
• Unwinding rate is high and easier process.
• Easy unwinding process.

Precision Winding Non-precision winding
The wound coil is arranged parallel or near
parallel.
The coil is cross wise wound.
The yarn density of the yarn package is high. The yarn density of the yarn package is low.
The stability of the package is low. The stability of the package is high.
The unwinding rate is low & process is
difficult.
The unwinding rate is high and process is
easier.
The yarn package is hard & more compact. The yarn package is soft & less compact.
The flanged package is used. The package is not necessary to be flanged.
Difficult to dye, only surface of yarn is dyed
properly.
Easy to dye, as dye can penetrate easily.
Winding angle is 0º or near 0º. Winding angle is greater than 15º.
The package is wound with one or more yarn. The package is wound with single yarn.
Yarn tension is comparatively high. Yarn tension is comparatively low.
No. of coils remain constant from the first
layer to last layer.
No. of coils per traverse of yarn guide
decrease up to the full diameter of the package
with the increase in package diameter.
No air gaps. Air gaps is found.

Types of package winding
• Parallel winding (Wrap beam, warper’s beam
or bobbin)
• Near parallel winding (pirn, cop, flange
bobbin)
• Cross- winding (cheese, cone, spool for jute)

Parallel winding
Two flanges contain both sides of the package
and yarns are wound parallel. In this process
there is no necessity of traversing.

Advantage:
• Many yarns can be wound at same time.
• No need of traversing mechanism.
• No change of yarns twist.
• Side with drawl is possible.
• No balloon formation.
Disadvantage:
• Need flange at the both sides of package .
• For yarn unwinding need separate mechanism.
• Over end withdrawal is not possible.
• The package is not stable.

Near parallel winding
This package contains one or more yarn are laid
very nearly parallel to the layers on the package.
Layers contain continuously inner side of the
package.

Advantage:
• No need of flange.
• Small balloon size.
• More dense package.
• Suitable for high speed weft supply in conventional loom.
• Side and over end withdrawal is possible.
• No change of yarn twist.
Disadvantage:
• Cannot be side withdrawal except warper’s beam..
• This is not stable.
• Need of traversing mechanism.

Cross winding
This is wound crossly by only one yarn.
Yarn is wound at appropriate helix angle (˃15º) so
that the yarn layers cross one another to give
stability of the package.
Advantage:
• No need of flange.
• Yarn package is very stable.
• Over end withdrawal is possible.
• Extra mechanism is not required for unwinding.
• High rate of unwinding.
• Suitable for wet treatment on yarn.
Disadvantage:
• Yarn twist is changed in this method.
• Balloon size is formed during unwinding.
• Need of traversing mechanism.
• Side withdrawal is not possible.
• Increase yarn hairiness and more yarn breakage.

Auxiliary function of winding
Creeling: This is a transfer operation. Creeling is the
placement of full packages in position ready to be unwound
as part of the transfer operation. Removal of empty
packages & placing the full packages is called creeling.
Piecing: Piecing is the finding & connecting of the
ends of yarn on the package. The connecting between
the ends can be made by knotting, adhesion or welding.
Such connections are required whenever an end breaks or
when a creeling operation has been completed.
Doffing: Doffing is the removal of full package by
empty package in delivery side.

Yarn withdrawal or unwinding
Unwinding process of yarn from a package is called
withdrawal of yarn. There are two types of withdrawal:-
1. Side withdrawal
2. Over end withdrawal.
Side withdrawal
This process is used for flanged bobbin. Package must
rotate positively or negatively. There is no change in yarn
twist and balloon formation does not occur. Side
withdrawal is preferable for flanged packages as the yarn
does not touch with the flanges. The package has to rotate
during the yarn withdrawal.

Advantages
• The yarn does not rotate upon withdrawal
• Yarn twists remain constant
• No balloon formation
Disadvantages
• At high winding speeds, due to inertia, the rotation of spool may
lead to tension variations in the yarn.
• This process is costlier for practical use.
• Low rates of yarn withdrawal.

Over end withdrawal
This process is used for non-flanged bobbin. Package is
stationary and there is balloon formation. Here speedy unwinding
possible & twist formation occurs. For ringframe bobbins, over end
withdrawal is performed by keeping the package in almost upright
conditions. As one coil comes out from the ringframe bobbin, one
twist is either added or subtracted from parent yarn depending on
direction of twist in the yarn.
Side-end withdrawal
Over end withdrawal

Advantages
• Very high rates of yarn withdrawal.
• Not so expensive.
• Do not necessary to rotate the package.
• Flanged is not required.
Disadvantages
• Balloon formation.
• Change the amount of twist of the yarn.

Types of Wound Package
• Parallel wound package
• Near- parallel wound package
• Cross wound package

In parallel wound package, yarns are laid parallel to each other. This
helps to maximize the yarn content in the package. However, parallel
wound packages suffer from the problem of stability and layers of coils
can collapse specially from the two sides of the package. Therefore,
double flanged packages are sometimes used for parallel wound
packages.
Example: Weaver’s beam, Warper’s beam.
In nearly parallel wound package, successive coils of yarn are laid with
a very nominal angle. The rate of traverse is very slow in this case.
Example: Pirn, Cop
In cross wound package, yarns are laid on the package at considerable
angle. As the coils crosses each other very frequently, the package
content is lower than that of parallel wound package. However, cross
wound package provides very good package stability as the coils often
change their direction at the edges of the package.
Example: Cones, Cheeses.

Winding Process
Total winding process can be divided into three zones-
• Unwinding zone
• Tensioning and clearing zone
• Winding zone
In the unwinding zone, yarns are unwound from the
supply package which is ringframe bobbin in most of
the cases. Yarn balloon is formed due to the high speed
unwinding of yarn from the supply package. Unwinding
tension varies continuously as the winding point shifts
from tip to base of a ringframe bobbin and vice versa.
Besides, the height of the balloon also increases as the
supply package becomes empty.

Winding Process/ Zones of Winding

In the second zone, tensions are applied on the yarns by
using tensioners so that yarns are wound on the package
with proper compactness. The objectionable yarn faults
as well as other contaminants (coloured and foreign
fibres) are also removed by using optical or capacitance
based yarn clearer.
In the third and final zone, yarns are wound on the
package by means of rotational motion of the package
and traverse motion of the yarn guide. Based on the
operating systems employed in the winding zone, two
major winding principles have evolved.

Yarn Guide
In winding and unwinding, it is necessary to control the yarn path.
For side withdrawal, it is possible for the yarn to pass along a smooth
unvarying yarn path. But for over end withdrawal the yarn does not
move along fixed path because rotary motion is imparted the yarn
winding. For a given yarn speed and package size, the position of
yarn guide will determine the balloon shape and the yarn tension.
Guides are made of hard smooth steel or ceramic.
Function of yarn guide
• Control the yarn path.
• Minimize yarn vibration.
• Reduce the chance of balloon formation.
There are two types of guides: Type-A is closed and Type-B is open.

Type-A (Closed):
• Closed guides require a yarn end to thread.
• Closed guides give higher friction with yarn.
• No possibility of yarn running out.
• More costly.
• Takes time for threading which reduce the speed of the
operation.
Example- Ceramic insert, Trumpet, Bush.
Type-B (Open):
• Open guides do not require a yarn end to thread.
• Open guides give less friction with yarn.
• Possibility of running out the yarn.
• Low cost and easy process.
• Speed of operation is comparatively higher due to no need of
threading.
Example- Post, Pig tail, Slotted guides.

Tension Device in Winding
Yarn tensioner is a device by which the required
tension is apply to the yarn. It is an important
device because it enables us to provide necessary
tension to the yarn as it moves through the
different parts of the machine.

Importance/effects of tensioning device
For natural fiber
Too high tension:
• Can damage the yarn.
• Breakage rate may greater.
• Elongation properties may change.
Too low tension:
• Can lead to unstable or loose packages which will not unwind
clearly.
• Variation in yarn tension in different parts of a wound package can
cause undesirable effects.
For man made fiber:
Too high tension can cause molecular change which effects dye ability
and random variation in color shading.
For staple or spun yarn:
Too high tension may cause the breakage of yarn at thin place.

Factors of selecting tensioner/
Requirements of tensioning device
• The device must be reliable to control uniform tension.
• It must be easily threadable.
• It must neither introduce nor magnify tension variations.
• It must not introduce differences in twist.
• It must not be affected by wear.
• It must be easily adjustable.
• It must not be affected by the presence of oil or dirt.
• It must not encourage the collection of dirt and lint.
• It must be capable of easy cleaning.
• The operating surfaces must be smooth.
• It must be inexpensive or cheap.
• It must be simple in design & operation.
• It must not damage the yarn.

Types of tensioning device
Tensioning device can be classified in two ways as follows-
• Depending on the type of the working member acting on the yarn.
• According to the working principle of the tensioning device.
Depending on the type of the working member acting on the
yarn:-
1.Ball type tensioner 4.Roller type tensioner
2.Washer type tensioner 5.Comb type tensioner
3.Disc type tensioner 6.Two-zone type tensioner
According to the working principle of the tensioning device:-
1. Capstan (multiplicative) tensioner
2. Additive tensioner
3. Combined tensioner
4. Automatic tensioner

Capstan tensioner method
It is a simple form of yarn tensioner. It works by passing the yarn
around fixed posts where the tension on the yarn is provided from
the friction between the posts and yarns. This induces a capstan
effect which follows the classical law.
Output tension = input tension x eµθ
Or, T2 = T1 x eµθ
Where, µ = coefficient of friction
between yarn & post
θ = angle of lap (in radians)
= θ1 + θ2 + θ3
T₁ = input tension
T₂ = output tension
e = constant = 2.718

Additive tensioner method
In this device a dead load or spring is used to give a fixed increment of
tension. The yarn is passed though the middle of the two surfaces in
contact & the force is applied above to give suitable tension to the
yarn.
Here, T2 = T1 + 2µF
Where, T2 = output tension
T1 = input tension
F = applied force
µ = coefficient of friction between yarn & surface of tensioner.

Combined tensioner method
It is the combined system of capstan & additive tensioner. The device
permits the tension level to be raised to any desired extent but it does
not permit a reduction in tension. It is seldom used.
Here, T2 = T1eµθ + T1 + 2µF
Where, T2 = output tension
T1 = input tension
θ = angle of lap (in radians)
µ = coefficient of friction.

Automatic tensioner method
This is a special type of tensioner. In this device the yarn tension is
controlled automatically. There is a lever which one side contains
spring loaded disc & another side contains applied load. If yarn
tension is very high then applied load decreased & spring loaded
device control tension moving upwards. Again if yarn tension is low
then applied load increased & spring loaded disc back its proper
level (downwards) & thus control the tension & known as negative
feedback.

Yarn cleaner/Slub Catcher
Yarn cleaner is the device which is used to remove the following
faults of yarn in order to increase the yarn quality & weaving
efficiency. Faults removed by yarn cleaner:-
1. Thick & thin places in the yarn.
2. Slubs & neps.
3. Loose fibres.
4. Foreign materials.
Yarn cleaners must be kept clean otherwise their contamination with
dust and false operation of yarn cleaners is possible i.e. the
formation of additional knots.

Balloon theory
The rotation applied to the departing yarn during at
high speed of the yarn unwinding from a stationary
Spinning cop, the yarn is thrown by centrifugal force
away from the cop axis & circumscribes in space a
plane is called balloon. It is characterized by the height
‘h’ as shown in figure.
In the process of yarn unwinding from the cop every
element of the yarn in the balloon performs a
complicated movement along the yarn axis & a
rotational movement around the cop axis. The shape of
balloon depends on the tension of the yarn at the
unwinding from cop.
Grishin’s formula for the tension generated in a
ballooning yarn states that “The yarn tension is a
function of the balloon height as well as other factors
which need not be considered here.”

Factors affect the size of balloon
Count of yarn:
Finer count, higher balloon size and vice-versa.
Winding and unwinding speed:
Higher speed, higher balloon size and vice-versa.
Size and shape of the package:
Larger package size, higher balloon size and vice-versa.
Position of package:
Greater distance, higher balloon size and vice-versa.
Lift of the package:
Greater lift of the package, higher balloon size and vice-versa.

Winding Parameter
• Winding rate – m/min.
• Winding on dia – cm.
• Yarn traverse velocity- m/min
• Angle of wind- degree
• Package velocity – m/min.
• Net winding velocity – m/min.

Winding rate:
Winding rate is defined as the amount of yarn to be wound
on the package per unit time i.e. the length of yarn in meter
wound on package per minute. Its unit is m/min.
Winding on diameter:
The diameter of the package on where the winding is done
is called winding on diameter. It may vary according to the
package. Its unit is cm.
Traverse velocity:
Traverse velocity is defined as the amount of traverse
happened during winding per unit time i.e. the length of
traverse in m/min is called traverse velocity. It is denoted
by Vt and its unit is m/min.

Surface velocity:
The rate of winding which is done on winding on diameter
is called surface velocity. It is denoted by Vs and its unit is
m/min.
Net winding velocity:
By dividing the traverse velocity with the sine value of
winding angle is called net winding velocity. It is called real
winding rate. It is denoted by Vr and its unit is m/min.
Angle of wind:
This is the angle contained between a warp of yarn on the
surface of a package and the diametrical plane of the
package. Angle of wind may vary with the traverse speed.
Number of coils in a layer will be decreased with increasing
the angle of wind. As a result amount of yarns will less on
the package. It is denoted by Ɵ(Theta).

Coil angle:
The angle between the vertical axis of the package
and the yarn is called coil angle. It is denoted by β.
Coil angle may increase with the decrease of angle
of wind.
β = Coil angle β
Ɵ = Angle of wind Ɵ
α= Angle of crossing μ
μ = Angle of reversal α

Key parameters in winding
The key parameters in winding are-
• Slub catcher setting
• Yarn tension level
• Winding speed

Winding fault
• Formation of patches on the
yarn.
• Incorrect winding speed.
• Tension variation.
• Dirty package.
• Incorrect shape of package.
• Too much knot in the yarn.
• Excessive full bobbin.
• Piecing up.
• Over lapping.
• Not get shaped properly
• Twist variation
• Dirty package
• Two end winding.
• Mixing yarns of different linear
density.
• Pattern winding which is the
result of the coincidence.
• Greasy & dirty yarn.
• Poor yarn clearing & snarling.
• Breakage of yarn
• Soft or hard package
• Oil or grease package
• Hairiness package
• Slack knot
• Poor unwinding

Waste in winding
During winding wastes are produced due to different causes. Some
of them are as follows:-
– Due to knots
– Ends remaining after tying
– Yarn slough off
– Remains of coil on the package
– Short ends dropped at threading
– Greasy & dirty yarn
– Workers negligence
The amount of waste depends upon the size of the spinning
bobbin & breakage rate. With the increase of the package size &
reduced breakage rate the amount of waste is reduced. On the
average the amount of wastes is 0.1% to 0.5% of the amount of
wound yarn. They should be collected for subsequent processing.

Winding efficiency/Calculation
It is the percentage expression of ratio of actual
production & calculated production.
 Actual production < Calculated production.

Factors related to winding efficiency
Winding efficiency depends on the following factors:-
Spindle or drum speed:-
• If spindle or drum speed increases then winding efficiency
increase.
Yarn count:-
• Yarn count is proportional to winding efficiency i.e. when yarn
count increased then winding efficiency increased.
Yarn quality:-
• Higher the yarn quality, higher the winding efficiency.
Worker efficiency:-
• Winding efficiency directly related to winding efficiency. Higher
the worker efficiency, higher the winding efficiency.
Humidity:-
• Humidity α Winding efficiency (for cotton yarn)
• Humidity α 1 / Winding efficiency (for other yarn)

Work load per worker:-
• If work load increased then winding efficiency decreased.
Maintenance & over hauling:-
• If maintenance & over hauling of a machine is not correct then
winding efficiency is low.
Power failure:-
• When power failure increase then winding efficiency decrease
Creeling time:-
• Higher the creeling time, lower the winding efficiency.
Doffing time:-
• When doffing time decreases then winding efficiency increase.
Capacity utilization:-
• When capacity utilization decrease then winding efficiency
increase

Reasons of lower efficiency
• Power failure.
• Improper Maintenance & over hauling.
• Absenteeism due to emergency personal causes.
• Natural disaster.
• Less skilled labor.
• Labor unrest.
• Shortage of spare parts & raw materials.
• Management problem.
• Strike.

Mathematical calculation
1. Calculate the time required for winding 400 lb of 12 Ne Cotton yarn on 10
drums. The actual production per drum is 560 yds/min. [12 hrs]
2. How much time will be required to wind 2388 lbs of 20 Ne cotton yarn on 40
drums of a super speed cone winder, if the calculated winding rate is 1298
yds/min and efficiency is 80%. [16 hrs]
3. Calculate the production of a winding machine/min from the following
particulars: [1037.456 yds]
RPM of winding drum : 4956
Diameter of winding drum : 3 inch
Efficiency : 80%
4. Calculate the production/shift of a cone winding machine from the following
particulars: [ 628 lb]
Efficiency : 70%
No. of drum : 120
Count of the yarn : 32 Ne

5. Calculate the production/8hr of a cone winding machine from the
following particulars: [1519.98 lb]
Efficiency : 90%
No. of drum : 120
Count of the yarn : 32 Ne
6. Calculate the time required for winding 60000 lbs of 54 Ne Cotton yarn
on 500 drums. The calculated production of per drum is 630 yds/min and
efficiency is 90%. [160 hrs]
7. Calculate the time required for winding a cone from the following
particulars: [12.58 hr]
Weight of yarn on the cone : 2 lbs
Yarn count : 40 Ne
Circumference of the drum : 20 inches
Rpm of winding drum : 200
M/C efficiency : 80%

8. Actual output/spindle/min is 672 lbs of 12 Ne cotton yarn. Calculate the
time that will be required to wind 1200 lbs of yarn on 30 spindles. [10 hrs]
9. Calculate the time required to prepare 9 sets of a 8 warpers beam each on
2 warping machine. The calculated production of the machine is 30000
yds/hr and the length of warp on each beam is 20000 yds and efficiency is
85%. [28.24 hrs.]
10. The winding rate of a modern high speed cone winding machine is 800
yds/min. Calculate the no. of drums required to wind 388 lbs of 80 Ne yarn
in 8 hrs if efficiency is 84% and wastage is 1%. [40]
11. Calculate the number of spindles of a modern automatic pirn winder
that would be required to wind 280 lbs of 20 Ne yarn in 8 hrs when the
production per spindle per hr is 1.4 lbs. [25]
12. Winding rate of a cone winding m/c is 980 yds/min. Calculate the
number of spindles of a modern automatic pirn winder that would be
required to wind 3024 hanks of 20 Ne yarn in 4 hrs. Efficiency is 90%. [12]

13. Calculate the number of drums required to wind 1600 lb of 46 Ne of
cotton in 8 hrs on a high speed winding machine with production rate 651
yds/min at 92% efficiency. [215]
14. The winding drum of a high speed cone winder having a diameter of 3
inch makes 2870 rpm. The actual amount of yarn wound in 9 hrs was found
to be 332838 yds. What is the efficiency of the machine? [82%]
15. Production of pirn winding machine per shift per spindle is 10 lbs for
30 Ne cotton yarn. Calculate the machine efficiency if the machine run at
600 yds/min. [87.5%]
16. Calculate the number of warper beam and length of warp that can be
made from 1500 cones, each of which contains 1.5 lbs of 40 Ne cotton
yarn. Total required no. of ends is 3000. [2]
17. How long will it take for a winder to wind 3 lbs of 16 Ne yarn if the
winder operates at 745 yds/min with the efficiency at 95%. [56.97 minute]

Warping
Good warping is half sizing
Warping is the heart of weaving

The parallel winding of warp ends from many winding packages
(cone or cheese) on to a common package (warp beam) is called
warping.
The operation of winding warp yarns into a beam usually in
preparation for sizing , weaving or warp knitting is also called
warping.
Objects of warping:
The object of warping is to convert a predetermined number of
single end packages such as cones or cheeses into a sheet of yarn of
specified length & width. The individual’s ends in the warp are
uniformly spaced across its full width. The warp yarns comprise
one of the systems of yarns required to produce a woven fabric &
also for warp knitting. The objective at warping, as erroneously
considered by many is not at all to remove yarn faults, the breaks
due to these being only incidental.

The essential features of a good warp are as follows:
1. Sufficiently and uniformly strong.
2. Uniform in cross section.
3. Uniform warp tension.
4. Uniformly sized.
5. Less hairy and clean.
6. Minimum no. of knots .
7. Proper or standard size and types of knots.
8. Free from neps, slubs and loose fibers.
9. Parallel arrangement of warp yarn in the weavers beam.

Importance of warping:
1. Constructions of beam warp yarn.
2. Constructions of a parallel yarn sheet.
3. Modifying the faults of yarn like thick & thin places, large
knots etc.
4. Winding the predetermined length of yarn.
5. Combination of small packages.
6. Finding long length of warp yarn.
7. Accelerating the next process.

Requirement of warping
Warping should meet the following requirement:
1. The tension of all wound ends must be uniform and possibly
constant during all the time of withdrawal from supply packages,
otherwise the rate of breakage will be increased & the structure of the
ready cloth will be impaired.
2. Warping should not change the physical & mechanical properties of
yarn. The tension should moderate to allow the yarn to completely
retain its elastic properties & strength. The yarn should not be
subjected to sharp abrasive action.
3. The surface of warping package must be cylindrical. Therefore, the
spreading of yarn (density) throughout the whole width of warping
must be as uniform as possible.
4. A pre determined length of warping should be observed.
5. The production rate of warping should be as high as possible.
6. The yarns in the sheet should be in uniform spacing and no broken
ends in the beam.
7. The yarns in the sheet should be in uniform tension.
8. The yarns in the sheet should be of a predetermined length.
9. The sheet should be containing a predetermined number of ends.

QUALITY PARAMETER CHECK RESPONSE
Beam surface smoothness No ridge beam allowed, clean the yarn
guide & check the tension for uniformity.
Homogeneous beam diameter Check the alignment of beam & drum,
drum and creel etc.
Yarn exhaustion Replace exhaustion cone with new one.
Yarn break Tying the head end with tail end with
standard with fail size <3 mm.
Checking point before Warping

Types of warping machine:
1. Direct/beam/high speed warping
2. Sectional warping
3. Ball/Cross warping

Direct Warping
Direct warping denotes the transference of yarns from single-end
yarn packages directly to a beam in a one step process. This means
that there are an equal number of packages in the creel area as there
are ends on the beam, except in the case of a magazine creel. A
weavers beam may have up to 10,000 ends and if this were to be
produced directly it would be necessary to have up to 10,000 creel
packages. Such an arrangement would be very difficult to
accommodate and manage; consequently it is normal practice to
produce warper’s beams which may contain up to about 1000 ends
and these are combined at the sizing stage. Because of the
difficulties involved in combining the ends, patterned warper beams
are seldom produced on the direct system and any pattern that is
produced is achieved by combining beams of various colors at the
later stage of sizing. This imposes limitations which can only
overcome by changing to pattern weaving.

Symmetric diagram of direct warping machine

Features of high speed/Direct warping
• To produce a warp beam from solid color or single type and
count of yarn.
• High speed and high production.
• This process require high amount of yarn.
• Produce better quality of beam.
• Sizing is always done after warping.
Use of high-speed warping machine
• Producing one color fabric like gray fabric
• For producing one/single color fabric
• For the same count of yarn
• Example: Shirt , Pant , Polo Shirt etc.

Sectional Warping Process
In sectional warping sections are made sequentially and because of
this the process is rather slow; it is the practice therefore to produce
weavers beam for colored fabric production like stripe, check etc. The
result is that the sectional warping is used mainly for short runs or for
complex color patterns.

Features of sectional warping
• To produce fancy fabric of different colors.
• Hand weaving use sectional warping.
• Control of uniform tension is very difficult.
• It consists of two process: First is warping on drum and second
is beaming.
• Used to produce weavers beam from small amount of yarn.
• To produce weavers beam from which do not required any
sizing material to be applied before weaving. But sometimes
sizing is done before warping.
• Weavers beam is may be found immediately after warping.
• Costly process as production is low.
• A tapered beam or drum is used.

Ball warping
Ball Warping is an intermediate process
for storing yarn for transport, dyeing or
reserve. It does not produce a beam. The
usual form is a cross wound cheese in
which multiple ends are wound at the same
time in a ribbon which contains perhaps
hundred or more ends. In ball warping
process, individual strands of yarn are
removed from yarn packages and collected
into rope form suitable for rope dyeing.
Threads, about 350-500 in number are
formed into ropes. Individual warp yarn
are collected into rope form and wound
onto a log and produce a ball warp on Ball
warping machine. In ball warping, all the
packages are loaded into the adapters of
the creel of ball warping machine. The
creel is normally designed to
accommodate about 330 to 430 packages.

Check List Before Production
With the production before data control operator will call-up the
following for recording:
1. Warp length shift.
2. Down time.
3. Efficiency.
4. No. of thread breaks.
5. No. of warp beam doffed.
6. Time for thread repair.
7. Time for beam change.
8. Operator must check yarn quality in term of count, material
and color with customer demand.
9. Operator must check yarn quality in term of strength and
record yarn break rate. Standard for good quality yarn 10
breaks/10,00,000 meter.

Control system in warping
• Tension- To prevent snarling or entanglement.
• Baloon control- To prevent entanglement with other.
• Stop motion- To produce quality fabric.
• Braking device- To stop the machine instantly.
• Yarn cleaner- Proper setting should be maintained to remove
yarn faults.
• Surface speed of warp beam
• Proper yarn density i.e. ends/inch.
• Relative humidity- To reduce end breakage.
• Traverse control
• Fly control

WARPING ELEMENTS & MOTION
Each warping m/c has the following warping elements &
motion:
1. Warping creel for accommodation the bobbin.
2. A builder motion.
3. A guide reed for uniformly spreading the yarn over the warp
width.
4. A measuring motion registering the warping length.
5. An automatic knocking off motion to stop the m/c up on
achieving the required length of warping in case of yarn
breakage.
6. A starting & stopping motion.
7. Warping m/c is furnished with package doffers signal devices,
blowers.

Flow Chart of Warping
Cone
from
winding
Creeling
Control
System
V-Reed/
Expanding
comb
Measuring
Roller
Winding
on a drum
or beam

Diagram of yarn path in machine
Main Parts:
1. Yarn cone or Cheese
2. Balloon Breaker
3. Yarn tensioner
4. Yarn guide
5. Ceramic guide
6. Auto stopper
7. V-reed
8. Lease rod
9. Roller
10.Pressure Roller
11.Pre-beam

COMPONENTS OF WARPING MACHINE
HEAD STOCK:
1. Guide Reed : Uniformly spread the yarn over the warp width.
2. Adjustable V-Reed : Guides the yarn to follow the fixed path.
3. Speed Controller : control the speed, crawl speed or full speed.
4. Pressure Roller : Exert required pressure to the warp yarn.
5. Measuring Device : Measures the length of the yarn.
6. Beam Bracket : Holds the warp beam.
7. Emergency Stop Device: For emergency stop.
8. Automatic Knock Off : Stop m/c at achieving required length of
beam or in case of yarn breaks.
10. Electrical Panel Board : To give the automatic controlled function.
11. Break assembly: It stops the machine instantly in case of yarn
breakage.
12. Driving drum: Beam is in contact and control with driving drum.
13. Beam bracket: To support and hold the beam.
14. Lease rod : Used for separation of yarns individually.

Features/Functions of components of headstock
1. Adjustable or variable v-reed or wraith: To control the width
of the warp beam.
2. Measuring & making device: Measure the amount of warp
yarn on the beam & marks the yarn.
3. Yarn speed controlling device: To control the speed of yarn.
4. Pneumatic pressure unit: To press the warp beam with the
surface contact of driving drum.
5. Break assembly: It stop the m/c after read length is wound on
beam.
6. Driving drum: Beam is in contact & control with driving drum.
7. Stop motion: Used to stop the m/c after read length is wound
on beam.
8. Beam bracket: To support & hold the beam.
9. Lease rod: Used for separation of yarn individually.

Components of warping machine
CREEL:
1. Cone Holder : Hold the cone or arrange the cone in the creel.
2. Yarn Guide : To guide the yarn.
3. Tension Rod : Maintain yarn tension by upper & lower disc
tensioner.
4. Ceramic Guide Disc : To guide the yarn from creel to warping
m/c.
5. Auto Stop Sensor : To sense the breakage yarn.
6. Creel Panel Board : Display where the yarn break
7. Indicator: To indicate yarn breakage in package
8. Stop device: To stop the machine when yarn will be broken.
9. Blower or suction fan: Remove the dirt & dust from the yarn.

Function of components of creel:
1. Cone or cheese spindle for high speed warping.
2. Thread guide: To pass through the yarn in the required way.
3. Tensioner: To keep the yarn always in a uniform tension.
4. Yarn cleaner: To remove various faults of yarn like slubs,
neps etc.
5. Suction fan or blower: To remove the dirt & dust from the
yarn.
6. Breakage indicator: To indicate breakage in package.
7. Stop device: To stop the m/c when yarn will be broken.

Types of Creel
V-creel
This type of creel is in V-shaped.
It consists of wooden pegs
horizontally to hold the supply
package. This is arranged so that
the apex is in line with the centre
of the machine. The arm of this
V-shaped wooden frame diverges
on both sides from its apex. It
enables the ends to be withdrawn
easily from the supply package
without touching or getting
entangled with one another
during passing to the back of the
head stock of the machine.

Rectangular Creels
It is rectangular in shape. Frames are provided with pegs to hold
supply packages horizontally. Frames can be increased to
accommodate more number of supply packages and vice-versa. Each
frame consists of thread guides, indicator, lamps etc. It is mostly used
in slow speed warping machine.

Truck Creel/Mobile Creel
It utilizes Trucks or Mobile package carrier units. Each unit consists
of number of columns and tiers on either side and can be inserted on
the axis of the creel frame to be come apart of the creel. Tension units
are positioned in relation to the packages and the unit is movable.
Trucks can be creeled to the winding machine and there by minimize
handling of the supply package provided there are sufficient number
of trucks. This system is not cost effective as many trucks are
required.

Swivelling Creel
In swiveling creel, the pegs with full packages can move from
inside(reserve) position to the outside(working) position when the
running packages are withdrawing. Thus considerable time is saved.
Then the operator replaces the exhausted packages with full packages
when the machine is running.

Difference between direct and sectional warping
Parameters Direct warping Sectional warping
Object / Use It is generally used to
produce warp beam for
grey fabric or solid color
fabric.
It is generally used to
produce warp beam for
yarn dyed (check/ stripe)
fabric.
Method of
Production
Several warpers beam are
produced here for getting
one weavers´ beam.
One warpers beam is
produced here for getting
one weavers beam.
No. of
Ends/beam
Ends/beam is less here.
Here, No. of beam is found
by dividing the total no. of
ends by creel capacity.
Ends/beam is higher here.
Sectional warping beam
contains equal no. of
ends as weavers beam.
Creel
Capacity
Usually lower than
sectional warping.
Usually higher than
sectional warping.

Parameters Direct warping Sectional warping
Yarn Tension Yarn tension is
comparatively higher
than sectional warping.
Yarn tension is comparatively
lower than sectional warping.
Yarn length on
beam
Higher length of yarn is
wound on a beam.
Length of yarn in the beam is
comparatively lower than direct
warping.
Sizing
Operation
One sized beam is
produced from several
no. of warpers beam.
One sized beam is produced
from one warpers beam.
Efficiency Efficiency is higher than
sectional warping.
(Single stage operation).
Efficiency is lower than direct
warping. (One additional
operation is required).
Stage of
Production
One stage production.
(Yarns are directly
wound on warpers
beam).
Two stage Production. (Yarns are
directly wound on warping drum
section by section; then the sheet
is transferred to warpers beam).

Faults & Remedies of Warping
Warp off centre of the beam:
Cause: Due to not carefully placing of creel wraith and flanged beam.
Remedy: Beam and wraith placed properly.
Uneven warp beam:
Cause: This effect due to winding of small no of ends on larger beam.
When the dents are bent or the spacing between dents is uneven and
for mixed count.
Remedy: Higher no of ends should be used.
Crossed ends:
Cause: Due to faulty knotting after yarn breakage and loose warp.
Remedy: Knotting and tension controlling.
Snarl formation in the warp:
Cause: Due to over tension, improper twist, improper position of
guide.
Remedy: By proper tension and twist.
Missing ends:
Cause: Due to faulty stopping device, exhausted cone or bobbin,
absence of cone or bobbin on creel.
Remedy: By using correct stopping device.

Hard beam:
Cause: Due to high tension.
Remedy: Tension and pressure maintained.
Unequal length :
Due to faulty measuring device.
Remedy: Use of correct measuring device.
Lapped end:
Cause: The broken end of yarn is not tied to the end on the warp beam
and overlaps the adjoining yarn. The beam is not properly brake & the
signal hook fails to operate.
Remedy: Tying the broken end to the end on the warp beam and use
of proper signal hook.
Piecing:
Cause: One broken end is pieced to another yarn end on the warping
beam.
Remedy: By proper joining.

Soft ends on the warping beam:
Cause: Breakage of a group of ends and piecing them in bundle or by
lapping. This defect is caused by the careless of the operator.
Remedy: Careful operation of operator and broken end should be
piece up properly.
Incorrect form of build:
Cause: Caused by non uniform spreading of ends in the guide reed &
its improper setting & conical winding in case of non uniform
pressure of the warping beam.
Remedy: Uniform spreading of ends and appropriate setting.
Slacks & irregular yarn tension:
Cause: It happens due to any one of these reasons-improper threading
of the yarn into the tension devices, ejection of yarn from under the
disc of the yarn tensioning device or yarn tension devices of poor
quality. Remedy: Proper threading of tension device and use of good
quality of tension device.
Broken ends on the beam:
Cause: A group of ends is broken and tied as a brunch or worked-in
with overlapping.
Remedy: Broken ends should be removed.

Conical winding on the beam:
Cause: It occurs due to incorrect load applied by the pressure roller.
Remedy: Correct load applied.
Improper length of warping:
Cause: It is due to malfunction of the counter and the brakes of the
measuring device & warp beams.
Remedy: Good measuring device
Causes of yarn breakage in warping:
1. Weak yarn. 2. Sloughing off.
3. Over lapping. 4. Knots/ bad splice.
5. Slubs. 6. Loose yarn.
7. Pig tail. 8. Cut yarn.
9. Bad tip of cone. 10. Short cone

Math:
A full beam produced on a direct warping system is having 1.4 m width and contains 500 ends
of 30 tex yarn. The empty and full beam diameters are 30 and 75 cm, respectively. If the beam
density is 0.4 g/cm 3, then calculate the length of warp and its mass in kg.
Solution:
Given,
Beam width, L= 1.4 m =140 cm
Number of ends = 500
Yarn count = 30 tex
Empty beam diameter, d = 30 cm
Full beam diameter, D= 75 cm
So, Volume of yarn on the beam =
π
4
(D²-d²)×L
=
π
4
(75²-30²)×140
= 519541 cm³
So, Mass of yarn = Volume×Density = 519541× 0.4 = 207816 gm =207.82 kg
So, mass of single yarn =
207816
500
= 415.63 gm
So, Length of warp yarn =
415.63
30
km = 13.85 km
So, the total mass of yarn on the beam is 207.82 kg and length of warp sheet is 13.85 km.

Sizing is the most important term for
weaving technology. After winding and
warping, sizing of yarn is done during beam
preparation. Sizing is done by applying
various types of size materials on the yarn.
During application of size materials steam
is needed.
Sizing is a protective process. The process
of applying a protective adhesive coating
upon the yarn surface to attain maximum
weaving efficiency is called sizing.

Purpose of sizing
Sizing is done during beam preparation for getting some
advantage of weaving. Purpose of sizing are:
• To improve the weave ability of warp yarn by making it more
resistance to action of weaving like friction, tension etc.
• To maintain good fabric quality by reducing hairiness,
weakness and by increasing smoothness, strength and
absorbency of yarn.
• To increase tensile or breaking strength of yarn.
• To increase the elasticity of the yarn.
• To reduce electrostatic formation.
• By adding size materials, yarn weight increases.
• To remove projecting fibers.
• To increase frictional resistance.

Properties of sized yarn/ Properties gained by yarn
after sizing:
Generally size ingredients are used for warp yarn but sometimes it
applies on weft yarn. Due to sizing following properties of yarn are
obtained:
• Higher elasticity
• Higher strength
• Lower flexibility
• Lower extension or elongation
• Higher frictional resistance
• Increased smoothness
• Less weakness
• Insensible to over drying
• Less hairiness

Types of Sizing
• Pure sizing: when the size pick up % is about 3 – 10
% it is called pure sizing.
• Light sizing: when the size pick up % is about 11 -
16% it is called light sizing.
• Medium sizing: when the size pick up % is about 17
– 40 % it is called medium sizing.
• Heavy sizing: when the size pick up % is above 40 %
then it is called heavy sizing.

Disadvantages of Sizing
• Cost of land and machine is high
• Requires lot of labors
• Requires utility like gas, electricity etc and their cost is high
• Cost of ingredients
• The process is long and it takes time
• There is a risk of degradation of yarn
• The yarn diameter is increased
• Requires robust loom
• It increases yarn stiffness
• The fabric needs to be desized before use
• Need knowledge and information about the size ingredients
• There is a risk of pollution
• Sizing changes the shade of colored yarn
• 100% size material cannot be removed
• Size material presence leads to uneven dying

Size Ingredients & Their Functions
1. Gums:
These materials from the base of size. There are two types of gum:
Natural: Until lately, mainly edible products were used as gums – starches
used as 75% of size ingredients and it will continue till to near future.
Common starches are potato, maize etc. Wheat flour, corn flour.
Synthetic: Polyvinyl alcohol, Carboximethyl cellulose, Polyacryloamide.
Functions:
• Coat the warp yarn with a film.
• Impart smoothness.
• Blind the protruding fibres to the yarn surface.
• Increase elasticity.
2. Lubricants or Softeners:
Vegetable & animal fats, Japan wax, tallow, cotton seed & castor oils, stearine,
glycerin, soap, TRO etc.
• Function:
• To give a softer feel to the sized yarn.
• To reduce stickiness of yarn.
• To smoothen the yarn.

3. Antiseptic or Anti Mildew Agent:
Phenol, boric acid, carboxylic acid, zinc chloride, sodium silicofluoride,
cresol etc. The quantity used is very low 0.1 to 2%.
Function:
• To prevent the growth of mildew.
• To prevent spoiling of the size mix during storing it for long time.
• To help to store the sized yarn.
4. Wetting Agent:
Sulphanol A, soap, avirol, alizarin oil etc. The amount of wetting
agents introduced into the size should not exceed 0.1 to 0.15 gm/ltr.
Function:
• To improve the size wet ability.
• Improve the penetration of the size between the fibres.
• Uniform distribution of the sizing solution on the yarn surface is
obtained.

5. Antifoaming Agent:
Silicones, stearine-paraffin emulsions, benzene, pyridine. The antifoaming
agents in amounts of 0.05 to 0.1 gm/ltr are stirred in a small quantity of warm
water.
Function:
• To prevent formation of foam.
6. Tinting Agent:
Blue is used as tinting agent.
Function:
• To increase the brightness & remove yellowish color of yarn.
• To prevent dusting off.
• To form a particular shade.
7. Weighting Agent:
The most commonly used substances are soluble inorganic powders such as
china clay, talc, barium or calcium sulfate.
Function:
• To give additional weights to the goods.
• To prevent opening of cloth.

Requirements of Sizing
In order to ensure good technological properties of sized
warps, the following requirements should be met in size:
Sized warp must be sufficiently strong, smooth & elastic.
• The sizing process must ensure the application of the
required amount of size on the yarn or the required size
regain.
• The tension of the warp yarns at sizing must be regular &
constant during all the time of warp unwinding from the
warping beams.
• Yarn stretch & loss in elongation should be within admitted
limits.
• The package, i.e the weavers beam produced must have a
cylindrical shape, the necessary winding density & the yarn
length.
• The sizing process must be efficient, economical & must
ensure the production of high quality sized warp.

Factors Considered Before the Selection of Size Ingredients
Before selecting the size ingredients the following factors must be considered:
• It must be Non-degrading to the yarn.
• It must be compatibility with equipment.
• It must be easily removal, if necessary.
• Provides good fabric characteristics if not removed.
• Least amount of dusting-off during weaving.
• Cost of the size ingredients must be less.
• It should not modify the tone of colored warps.
• No skimming tendency.
• Easily prepared.
• Lack of odor.
• No beam blocking.
• Compatible with other ingredients.
• Neutral pH.
• Insensitive to high heat.
• Rapid drying.

Properties of Size Ingredients
• Ease of preparation
• Uniform viscosity
• Absence of prolonged congealing and kenning at
application temperature
• pH control
• Absence of foaming properties
• Absence of prolonged tackiness
• Compatibility with other components of the size
• Stability towards decomposition
• Ease of desizing

Sizing variables
A good sizing depends on various factors. During sizing the following
variables should be checked and controlled where necessary:
• Viscosity of the size solution.
• Sizing machine speed.
• Size add-on levels.
• Concentration of the size mixture.
• Volume of the size box.
• Threading arrangements.
• Condition of squeeze rolls.
• Squeezing pressure.
• Hardness of squeeze rolls.
• Diameter of squeeze rolls.
• Number of size boxes.
• Yarn count and size box warp density per unit space.

Flow Chart For Sizing of Warp Yarn:
Size Cooking
↓
Creeling
↓
Yarn Feeding
↓
Sizing (in show box)
↓
Drying
↓
Leasing
↓
Denting
↓
Empty Beam Feeding & M/C Running
↓
Ends Cutting
↓
Doffing

The optimum level of size add-on depend on the
following factors:
• Type of fiber
• Type of size materials
• Yarn spinning technology
• Yarn count and twist
• Level of hairiness in the yarn
• Loom type and loom speed

Factors Influencing Size Pick up%
1.Viscosity of size paste in size box: Any variation in the
concentration or temperature alters the viscosity of the paste which in
turn affects both the level of size pick up and extent of penetration.
Initially as the viscosity increases, the size pick-up also increases. But
as the viscosity increases beyond a point, the size pick up is reduced.
2.Squeezing pressure and condition of squeezing nip: The
squeezing pressure determines the extent of penetration of the size
paste between the fibers of the yarn and also of the removal of excess
size paste and hence the level of the size pick up.
3.Speed of the sizing machine: Other sizing conditions remaining
unchanged, the size pick up increases with increasing sizing speed and
vice versa. This is because the time available to squeeze the surplus
size from the yarn is less at high speeds.
4.Depth of immersion roller in size paste: the depth of immersion
roller in the paste determines the duration for which the yarn remains
immersed in the paste. This duration in turn influences both the level of
size pick up and the extent of size penetration.

5.Level of size paste in the size box: Variation in the level of
size paste is an important source of size pick-up variations both
within and between beams.
6.Density of ends: When the density of ends is high, difficulties
are encountered in obtaining adequate and uniform size
penetration. Therefore size pick up may vary at these fabrics.
7.Yarn tension: In case of higher tension during sizing the set of
warp yarns encounter a stretch of comparatively higher tension
and thus the set of yarn increases in length. If this increase is too
high then the elongation property of the yarn will be decreased.
So the yarn will face comparatively higher breakage in
subsequent processes. On the other hand lower yarn tension
leads to uneven sizing. So the yarn tension must be optimal.
8.Yarn twist: In case of high twisted yarn penetration time
should be increased in order to obtain the optimal pick up %.
9.Dia. of the yarns: Yarn with greater dia consumes higher size
paste. Therefore, the higher the dia of yarn, the higher the
pickup will be added.

Sizing Process
Figure: Sizing Process
Necessary number of warp beam are set in the unwinding zone and warp yarn sheet are
passes through the guide. At first yarn are wetted in the hot water box called prewetting
box so that size liquor can easily penetrate into the yarn. Then yarn entered into the size
box and absorb size liquor. To avoid excessive size liquor absorption squeezing roller is
used. Then the size yarn is passed through the drying zone to dry the yarn. In the drying
zone there is splitting rod to separate individual yarn. After that the warp yarn is wound in
a beam called weavers beam which is ready for drawing and drafting.

Faults of Sizing
Underslashed Warps:
Causes:
• Due to insufficient size concentration
• Improper size feed to the size box
• Variable size level
• Dilution of size
• Strong squeezing of warp
Overslashed Warps:
Causes:
• Due to insufficient splitting of starch at size
preparation
• Weak squeezing
• Too deep immersion of the warp into the size box
Sticky Warps:
Causes:
• High sizing speed
• Low drying temperature
Over Dried Warps:
Causes:
• Low sizing speed
• Long stoppage of machine during sizing
• Very high temperature in the drying section
Gum Spots and Smears:
Causes:
• Splashes of size get on the squeezed warp
• Bad stirring of starch at preparation
• Improper coating of felts on the squeezing rollers

Non Uniform Size Regains:
Causes:
•Irregular heating of the size in the box
•Dilution of the size with live steam
•Non uniform pressure of squeezing rollers
Crossed and Lost Ends:
Causes:
•Lease rods are set too far apart
•Broken ends are improperly pieced up
•Bad warping
Improper Build of Beam:
Causes:
•Incorrect spreading of yarn ends in the reed dents
Incorrect Warp Length:
Causes:
•Disarrangement of the measuring and marking mechanism
•Improper adjustment of measuring and marking mechanism
Dirt Stains in Warp:
Causes:
•The size boxes and machine metal parts are dirty
•The size is cooked in non-galvanized iron kettles.
Shinnery:
Causes:
•Due to the friction between the yarn and drying cylinder
Sandy Warp:
Causes:
•Due to not crushed or grind the size material
Hard Sizing:
Causes:
•Excessive application of size material
Size Dropping:
Causes:
•Due to not optimum viscosity of the size solution
Uneven Sizing:
Causes:
•Due to over and under sizing.

Properties of a Good Sizing Material:
• Environmentally safe.
• Good film former.
• Reasonable use economics.
• Penetration of yarn bundle.
• Elasticity.
• Good film flexibility.
• Good specific adhesion.
• Good frictional properties.
• Transparency.
• Bacterial resistance.
• Reasonable strength.
• Controllable viscosity.
• Water soluble or water dispersible.
• Good hygroscopicity characteristics.
• Uniformity.
• Clean split at bust rods.
• Improves weaving efficiencies.
• No effect on drying.
• Reasonable extensibility.
• Recoverable and reusable
• Low static propensity.
• No skimming tendency.
• Easily removed.
• Easily prepared.
• Lack of odor.
• No beam blocking.
• Compatible with other ingredients.
• Good abrasion resistance.
• Neutral pH.
• High fold endurance.
• Insensitive to high heat.
• Low BOD.
• No build up on dry cans.
• Reduced shedding.
• Rapid drying.
• No re-deposition of size
• Insensitive to changes in relative
humidity.

Starch remains tightly bound in granules and therefore it does not act as adhesive in cold water. Cooking of
starch is required to make it soluble in water. The change in viscosity of starch solution during cooking is
shown in figure.
Within the granule, the chain molecules of amylose and amylopection are arranged radially in stratified
layers. External heat energy is required for the penetration of water molecule within the structure. The
temperature at which the thermal energy becomes sufficient to overcome hydrogen bonding within the
structure is called ‘gelatinisation’ temperature (P). Crystallization of starch is lost during gelation. As the
water penetrates, the chain molecules are pushed away from each other causing swelling of the starch
granule. This is marked by increased in viscosity of the solution (Q). This continues up to the point R. Aided
by the continuous shearing provided by the stirring, the starch granules finally break. The chain molecules of
amylose and amylopection come out within the solution causing reduction in viscosity (T). When all the
granules have burst, the viscosity stabilizes or levels off (T). When the solution is cooled, the starch gels due
to the formation of a rigid interlocked micelle-like structure having hydrogen bonding (U). This gel form of
starch can form a continuous coating on the yarn surface.
Cooking of Starch

Sizing-weaving Curve
For the sizing process, depending on the size materials used, there is a target add-on for
the optimum performance of the warp yarns in the weaving process. This can be
understood from the sizing-weaving curve. The solid line represents the warp breakage
rate whereas the broken line implies loom efficiency.
At very low level of size add-on, the yarn is not adequately covered by the size film
and therefore the yarn is not protected from the abrasion with various loom parts. So,
warp breakage rate is generally high at very low level of size add-on. The performance
of the yarn in weaving improves as the size add-on increases. The optimum add-on
level is marked by very low level of warp breakage rate. However, if the size add-on is
higher than the optimum level then warp breakage rate increases again largely due to
the loss of elongation and increase in bending rigidity of the yarns.

Different techniques of sizing:
• Hot melt sizing
• Solvent sizing
• Foam sizing
• High pressure sizing
• Electrostatic sizing
• Emulsion sizing
• Combined sizing
• Conventional sizing

Different drying system
1.Cylinder drying
a. Two cylinder drying
b. Multi cylinder drying
2. Hot air drying
3. Infrared drying
4. Combined drying

Automation in sizing
1. Size temperature control
2. Size level control
3. Steam pressure control
4. Moisture control in sized warp
5. Stretch control
6. Measuring unit control

Loom
Loom is a machine or device where woven fabric
is produced by the interlacement of at least two
sets of yarn called warp yarn and weft yarn.
Weaving is the process of fabric production by
the interlacement of at least two sets of yarn
called warp yarn and weft yarn.

Loom Motions:
In order to interlace wrap and weft threads to produce a
fabric, the following motions are necessary on any type of
loom:
• Primary motions
• Secondary motions
• Tertiary motions
Primary Motions: These are fundamental or essential
motion. Without these motion, it is practically impossible
to produce a fabric. It is for this reason that these
motions are called ‘primary’ motions. The primary
motions are :
• Shedding motion
• Picking motion
• Beat-up motion

Shedding motion is the motion of dividing warp yarn
sheet of weavers beam for inserting the weft yarn to
weave a fabric.
Picking motion is the second primary motion which is
required to insert the weft yarn through the shed of warp
yarn.
Beat-up motion is used to attach the last inserted weft
yarn with the fell of the cloth.

2. Secondary Motions:
These mechanisms are next in importance to the primary
mechanisms. If weaving is to be continuous, these
mechanisms are essential. So they are called the
‘secondary’ mechanisms. They are:
• Take-up motion
• Let-off motion
The motion of winding the woven fabric from the
weaving zone in the cloth beam to adjust the warp yarn
tension is called take-up motion.
The motion of unwinding warp yarn from weavers beam
to release the yarn in weaving zone to maintain proper
warp tension is called let-off motion.
Primary motion and secondary motion is called the basic
motion of a loom.

3. Tertiary Motions:
To get high productivity and good quality of fabric, additional
mechanisms, called auxiliary mechanisms, are added to a loom. The
auxiliary mechanisms are useful but not absolutely essential. This is
why they are called the ‘auxiliary’ mechanisms. These are listed below.
• Weft stop motion
• Warp stop motion
• Warp protector mechanism
• Weft replenishment / Warp mixing motion
• Cutter
• Temples
• Brake
• Selvedge

Preparation of weaving

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Preparation of weaving