Usage of QC tools for a quality problem

National Institute
of Fashion
Technology Patna
Apparel Quality Management
Assignment 1, 2
Submitted to –
Asst. Prof. Jayant Kumar
Submitted by –
Akansha Choudhary
BFT/19/286
1

Acknowledgement
I am deeply thankful to Mr. Jayant Kumar, Assistant Professor, DFT,
National Institute of Fashion Technology Patna, for his immense
support throughout the course of this assignment.
I thank National Institute of Fashion Technology Patna for providing
me the opportunity to perform this assignment.
2

Certificate
This is to certify that Akansha Choudhary, BFT/19/286 from BFT-
5, National Institute of Fashion Technology Patna, has successfully
completed her assignment titled “Exploration on the usage of
classical tools for a quality problem and presenting a report on the
same, Exploration on the usage of new tools for a quality problem
and presenting a report on the same”
Signature
(Jayant Kumar)
Assistant Professor
NIFT Patna
3

Contents
Topic Page Number
Open seam 6
Cause and effect diagram 6
Flow chart 9
Shade variation 13
Tree diagram 13
Affinity diagram 16
Bibliography 19
4

Assignment 1
Exploration on the usage of classical tools for
a quality problem and presenting a report on
the same.
5

Open Seam
Open seam is a defect where the stitch line is still intact but the yarns
in the fabric have ruptured.
Open seams are unsightly and compromise the integrity of the
garment seams. They are virtually always regarded as a serious flaw,
regardless of size Garment Defects. Open seams are not usually a
defect in a full order, but they can appear on isolated units owing to
poor folding or a worker's inappropriate technique.
Open Seam
When patching an open seam, visible traces of mending, such as
overlapping stitching, are common. In this report, two classical tools
will be utilized to solve the open seam problem.
Cause and Effect Diagram
In the following Fishbone diagram, we have tried to identify all the
possible causes of the open seam defect. The causes arise from various
factors that are made clear in the diagram. Our aim is to pull down the
given problem by the widest margin possible. The quality control tool
is followed by solutions to reduce the occurrences of open seams in an
industry.
6

Cause and effect diagram
Factors that cause the opening up of seams can be divided into four
major categories – Manpower, Method, Material And Machine.
Among manpower, lack of skill is the leading cause. Workers not being
enough able for the job is where the duty of employers comes into
question.
Workers being hesitant to the contemporary system is a factor that is
often not looked upon. The factory must take this issue tactfully.
Workers must be lent time to get perfectly used to innovations and
must be put under scrutiny for that time period. A factory not being
careful when choosing labor indirectly calls for losses.
Not handling garment components appropriately, which includes
improper alignment of piles, seems like an ordinary mistake, but
instead puts a whole garment lot at stake.
MAN
METHOD
MATERIAL
MACHINE
Insufficient
skill
Reluctance
towards new
techniques
Improper handling
of garment parts
Delicate
thread
Flawed threading
Non-regulated
stitching method
Tension is not
quantifiable
Unclear markings
for stitch line
OPEN
SEAM
Damaged
feed dog
Setting between
needle and hook
improper
Incorrect SPI
7

Poor material is a huge minus point. Stitching on a weak fabric is not
really controllable most of the time, which catalyzes the emergence of
defects like opened seams and broken seams. The apparel factory
must make sure to get associated with a guaranteed fabric supplier.
One of the best measures toward effective results is improvisation of
methods used in the industry. Setting up of the machine before
starting the sewing process is utmost crucial for unflawed stitches.
Threading not executed correctly is the predominant cause of open
seams. Incorrect thread tension is also a common origin of open
seams. Both of these errors can occur due to labor falling short of skill,
or because of sewing instructions not having been provided properly.
Oftentimes the sewing methods are not standardized, which is a
destructive manner of organizing an industry in the long run since this
method gives birth to a myriad of sewing defects, open seams being
one of them. Implementing strict and systematic sewing methods is
bound to reduce defects by an immense number.
Seemingly small things like the visibility of markings on the stitch line
make a huge difference. Stitch line very often deviates if the marking
on the fabric is thick or faded. The pen used to mark must have a thin
tip, and must be able to make smooth, clear lines on fabric.
Among machine problems for open seams, there is improper setting
or timing between needle and looper or hook. Machine not being set
to enough SPI (Stitches per inch) will give rise to several openings in
seams.
Metal teeth-like ridges that emerge from a hole in the throat plate of a
sewing machine are called feed dogs. A faulty feed dog hinders the
stitching process and frequently results in uneven stitches, broken
seams and open seams. The maintenance department of the factory is
responsible for methodical maintenance of its sewing machines.
Preventive maintenance must be performed time to time, and
corrective maintenance should be done as soon as a fault in machinery
is identified.
8

Solution for the factory –
 Train the sewing machine workers till they are perfectly capable of
operating machines and adapt to the new system.
 Do not assign workers the responsibility of handling material
unless you are convinced.
 Get associated with a trusted fabric supplier.
 Fix a standard operating method throughout the sewing unit.
 Make sure the workers are following proper sewing guidelines and
operating on the right machine settings by strengthening
invigilation.
 Strictly implement time to time preventive maintenance and
overhauling of sewing machines.
 Get the maintenance department within reach for corrective
maintenance without delay.
Flow chart
The given flow chart is a corrective measure process flow that exhibits
the ideal steps to be taken upon coming across a garment with an open
seam defect in the garment industry, which are beneficial for the
factory in long term.
9

Flowchart
c
Is
the defect
present in large
number
Is
the defect
small enough to
be fixed
Is
the
machine
faultless
Is
the
machine setting
right
Is
material
of standard
quality
Are
m/c instructions
erroneous
OPEN SEAM
DEFECT
Send the
garment for
mending
Reject the
garment
Ask
instructions
in-charge for
rectification
Ask worker to
follow sewing
instructions
properly
Re-employ
the worker
Contact the
fabric
supplier
Train the
worker in
operating the
machine
Yes
No
Yes
No
No
Yes
No No
Put the
machine
under
maintenance
Yes
Yes
Yes
No
Has
the worker
become able
enough
Fire worker
and employ
another
skilled worker
Yes
No
10

One can see that the foremost step that must be taken after noticing
an open seam defect is to find its occurrences. The same defect present
in a considerable amount of garment parts is an indication of a bigger
underlying problem.
If the defect is occurring not more than a handful number of times
among a massive chunk of garments from the sewing unit, then the
defect could have either arisen from an error by the sewing machine
worker corresponding to the defective garment component or from a
fault that the specific sewing machine contains. In this situation, the
seam must be closed right away by sending the garment to the
mending section, except when the opening is too large to be mended –
then the garment ends up in the trash bin.
When it is found that the frequency of open seam defects is becoming
significant, the entire sewing unit needs to be put under scrutiny.
Ideally, the first step is to check the machinery for faults. This is
where the maintenance department comes into play. An immediate
corrective maintenance is the absolute answer to finding machine
parts that are deprived of repair.
In case there aren’t machine faults, there is a chance that the sewing
instructions provided to the operators are not proper. The instructions
planner must be called for re-analyzing the machine instructions
paper. Finding no error in the setting instructions implies that the
sewing machine operators have not followed the instructions properly.
The action required for this situation is to teach the workers to read
the instructions and to tell the workers to follow them properly.
The quality of the fabric used is also a common cause for a large
number of open seam defects. A weak fabric is not suitable in this
situation. The fabric supplier should be contacted in case of material
shortcomings.
When all the above points are marked off as uninvolved, it is very
likely that the operators are not skilled enough for the job. The factory
is accountable for training them to handle and operate sewing
machines in a methodical manner. Firing the unskilled operators if
they couldn’t perform up to the mark and hiring new ones instead is a
very much valid decision which is beneficial for the factory.
11

Assignment 2
Exploration on the usage of new tools for a
quality problem and presenting a report on
the same.
12

ShadeVariation
The color shade of dyed fabric or the color defect of printed fabric
plays a significant part in determining fabric color quality. As a result,
quality inspection of color shade is required.
One of the most common issues with dyed or printed materials is
shade variation. A defective garment is one that has shades of different
colors. Shade variation in a garment happens when the depth of color
of distinct garment components differs, or when the shades of
separate garment pieces differ.
It is the garment manufacturer's job to ensure color consistency both
within a garment and between garments. During factory visits, the
buyer may request and inspect continuity records.
Shade variation
Tree diagram
The following tree diagram is partly a scientific approach towards
making it easier to reach the root cause of shade variation defect in the
apparel manufacturing sector.
13

Variation in
shade
Imbalance in
dyeing recipe
Dyers change recipe
ingredients
Change of dye stuff
brand
Run out of product(s)
from original recipe
Dyeing
machine
issues
Less predictability of
hydrolisation
Increased use of water
Lack of steam to heat
dyeing vessels
Shade across single
piece of fabric
Poor levelling from
incorrect timing of
dosing chemicals
Geometry of the
machine nozzle
Logistics
Backward integration
into dyeing
Dyeing performed by
commission dyers
Tree diagram
Shading issues occur due to numerous issues, which can be broken
down into three categories – Imbalance in dyeing recipe, Dyeing
machine issues and Logistics.
Imbalance in dyeing recipes simply happens when dyers alter their
recipe's ingredients. Due to cost reasons, they might switch dye
substance brands or it could occur because one or more of the
ingredients in the original mix are no longer available. The proper
preventive action to be taken here is to dye a lab sample first to ensure
that the finished shade is still same, although time is often an issue.
Shade variation issues pertaining to dyeing machines are fairly
popular in the industry. Although engineering of today enable
accurate shade match from one machine to another, and from one
batch to another batch even from multiple machines apart from multi-
14

chamber dyeing machines that generate matching shades in all
chambers, one must also interpret this broad statement from the
perspective of the liquor ratio used, as change in the amount of water
to be used severely affects the efficiency of dye stuffs and chemicals.
More the water used in the process, less predictable the effect of
hydrolization becomes. Installing airflow machines will sizably
increase the efficiency of dye stuffs, since they consume less water and
chemicals compared to jet dyeing machines.
There are two problems dyeing machines regularly come across which
unnecessarily delay the dyeing process by a large margin. One of them
is undersupply of steam that is required to fully heat the dyeing
vessels, and another one is repeated power interruptions.
Shade variation, a lot of times, occurs when shading is done across a
single piece of cloth. It can be from selvedge to selvedge or from center
to selvedge. It can simply occur due to poor levelling from unsuitable
capacity and timing of dosing chemicals. Geometry of the nozzle of the
machine also enables the defect occurring within the same fabric roll.
The increasing trend among apparel manufacturing companies
towards backward integration into dyeing reveals the rampant
dissatisfaction when it comes to handling dye quality issues. This leads
to employing commission dyers whose tools and methods cannot be
controlled straightaway. This poses a huge problem when commission
dyers outdo by producing giant batches beyond their capacity and
send those for processing at multiple dye houses to reach shipping
deadlines.
All the issues mentioned above together form an uncontrollable crisis.
Solution for the factory –
 Keep the dyeing process within your own corporate processing
line.
 Install airflow dyeing machines.
 Establish quality power system.
 A close working relationship with a few select commission dyers
must be created, bringing the quality management component to a
level that is nearly as excellent as in-house dyeing.
 Stipulate a strict tolerance level.
15

Affinity diagram
Below is the affinity diagram depicting controlling factors of dyeing
process that affect batch to batch shade variation.
Affinity diagram
Machine
parameters
Chemical
parameters
Process
parameters
Material
parameters
Speed Purity pH Yarn uniformity
Temperature Strength Pressure
Maturity of
fiber
Time
Chemical
composition
Liquor ratio Count variation
Dosing
Country of
origin
Recipe
Foreign
material
Liquor ratio Environment
Water
hardness
Fabric faults
Stability of
machine
Temperature Weave plan
Pressure Time
Rinsing Fastness
16

Batch to batch shade variation can occur due to various reasons in the
preparatory stage, which can be divided into two categories –
excessive heat setting and uneven pretreatment. In synthetic fibers,
heat setting affects on dye bond formation, while variation in shade
also occurs due to improper bleaching and scouring.
Among on process causes, using chemicals with different
concentration is the most common cause apart from irregular color
dosing . Shade variation very often arises when the concentration of
input chemical varies from one batch to another. Negligence of worker
is a common factor that is often brushed off.
A lot of factories suffer from lack of control on dyeing machine. It
mainly occurs when the rope length and cycle time differs from one
batch to another. It also happens when reel speed changes with loads
per nozzle, fabric GSM, cycle time, and other factors.
Running time can sometimes vary at different stages of dyeing,
followed by the variance of action of same chemicals or dye stuffs used
in different batches varying from batch to batch.
Fluctuation in power supply as well as repeated power cuts
considerably affect the dyeing process, thereby interfering between
fabric shades. A waver in temperature will cause shade variation.
Dye strength and reactivity are a couple of factors that affect fabric
shades from lot to lot as well as drum to drum. pH has a severe impact
on the dyeing process. Fixation pH is crucial to obtain a uniform shade
in reactive dyeing. A slight alteration in pH directly changes the
appearance of a dye stuff. The process of neutralization, if not followed
properly, will leave alkali residue that affects dyeing and causes shade
variation.
The soaping process is a critical stage that can have an impact on the
defect. Amount of soap, depth of shade, soaping time and temperature
can bring variation in shade. The final cationic fixing operation leads
to difference in shade in case of its depth and time.
A poor lab-to-bulk correlation can create huge losses. A fixed liquor
ratio, chemicals, the recipe, process stages, runtime and other factors
17

must be followed as allotted in order to save the fabric from any color
defects.
Apart from the preparatory and dyeing stage, the final finishing stage
is just as important for variation in color. Deviation in softener
quality, strength, concentration, pH are the leading factors in that
enable the defect in the finishing unit. Shade variation also emerges as
a result of unequal drying temperature.
Solution for factory –
 Follow the customary pre-treatment procedure.
 Use standard dyes and chemicals.
 Maintain the fixed dyeing cycle.
 Maintain the same liquor ratio from beginning to end.
 Retain equal amount of material per nozzle.
 Follow uniform dyeing procedure for the same depth of shade.
 Check the strength of dyes and chemicals from time to time.
 Sustain the lab to bulk correlation.
 Review the pH and hardness of water on a daily basis.
 Properly maintain equal finishing parameters which includes
drying temperature, squeezing pressure, and softener treatment,
etc.
18

Bibliography
Apparel Resources , 2009. Reasons for Shade Variations in Fabrics –
Kurt Müller, Area Sales Director, THEN Maschinen GmbH. [Online]
Available at: https://apparelresources.com/business-
news/manufacturing/reasons-shade-variations-fabrics-kurt-muller-
area-sales-director-maschinen-gmbh/
[Accessed 16 7 2009].
Kiron, M. I., 2014. Seam Defects | Common Seam Quality Defects in
Garments. [Online]
Available at: https://textilelearner.net/common-seam-quality-
defects-in-garments/
[Accessed 19 4 2014].
Sarkar, P., 2013. 9 Step Guide to Eliminate Fabric Shade Variation in
Garments. [Online]
Available at: https://www.onlineclothingstudy.com/2013/10/9-step-
guide-to-eliminate-fabric-shade.html
[Accessed 15 10 2013].
Seampedia, 2019. Stitch, how to avoid sewing defects. [Online]
Available at: https://seampedia.com/stitch-avoid-sewing-defects/
[Accessed 10 4 2019].
Team, F. R., 2019. 7 influencing factors for batch to batch shade
variation in knit dyeing. [Online]
Available at: https://www.textiletoday.com.bd/7-influencing-factors-
batch-batch-shade-variation-knit-dyeing/
[Accessed 23 7 2019].
19

Usage of QC tools for a quality problem

More Related Content

What's hot (20)

Similar to Usage of QC tools for a quality problem (20)

More from Akansha Choudhary (18)

Recently uploaded (20)

Usage of QC tools for a quality problem