Shrinkage

Name : MAZADUL HASAN SHESHIR
ID: 2010000400008
Batch: 13th Batch (Session 2009-2013)
Department: Wet Processing Technology
Email: mazadulhasan@yahoo.com (FB)
Blog: www. Textilelab.blogspot.com
Southeast University,Bangladesh
Department of Textile Engineering
PREPARED BY ©right

Shrinkage Definition :
A dimensional change resulting in a decrease in the length or width of a specimen
subjected to specified conditions is known shrinkage.
Reduction in length and width of fabric induced by conditioning, wetting,
steaming, chemical treatment, wet processing as in laundering, in chemical
practice and in literature the following terms have been used to describe the
shrinkage which occurs in testing procedure:
1. Relaxation shrinkage,
2. Felting shrinkage,
3. Compressive shrinkage,
4. Residual shrinkage.
Shrinkage

Shrinkage:
Shrinkage is the process in which a fabric becomes smaller than its original size,
usually through the process of laundry. Cotton fabric suffers from two main
disadvantages of shrinking and creasing during subsequent washing.
There are two types of shrinkage occurs during washing
1) Length wise
2) Width wise
Shrinkage

Cause:
Due to high tension during preparation of fabric which result in excess stretch in
yarn. This type of shrinkage is known as London shrinkage. Due to swelling of fibers
for fiber structure.
Glass plate
Shrinkage

Illustration of Shrinkage on Woven Fabric Caused
by Fiber and Yarn Swelling

There are Two Kinds of Fabric Shrinkage:
1. Relaxation Shrinkage
2. Progressive Shrinkage
Relaxation Shrinkage
This occurs because the fibers and yarns are under tension when the fabrics are
made. Later when the fabric is wet in a tensionless condition, relaxation occurs.
Progressive Shrinkage
This occurs each time a fabric is laundered. Unlike relaxation shrinkage which
occurs only once, progressive shrinkage continues and the fabric shrinks a bit
more with each laundering. Of the major fibers, only wool and viscose rayon are
subject to progressive shrinkage.
Shrinkage : Types

Relaxation shrinkage:
During manufactures fabrics and their component yarns are subjeceted to
tension under varying conditions of temperature and moisture content, after
manufacturing when the fabric is taken from the machine and keep on floor or
store room, then the fabric tends to shrink, this type shrinkage is called
relaxation shrinkage.
Felting shrinkage:
In case of wool fibers dimensional changes can be magnified by felting shrinkage.
When untreated wool fibers are subjected to mechanical action in the presence
of moisture.
Compressive shrinkage:
A process in which fabric is caused to shrink in length by compression. The
process often referred to as controlled compressive shrinkage.
Residual shrinkage:
after washing the fabric is shrunk. This type of shrinkage is called residual
shrinkage. Residual shrinkage is the main factor of garments industry.
Shrinkage: Types

Causes:
Shrinkage is mainly due to yarn swelling and the resulting crimp increase during
washing in case of cotton fabrics. Yarn swelling percentage is more in polyester
cotton blending yarn.
Influencing factors:
 Twist factor: twist factor increases so that shrinkage will be increases.
 Stitch length: stitch length increases so that shrinkage will be increases.
 GSM: GSM increases so that shrinkage will be decreases.
 Elasticity of yarn.
Shrinkage : Causes-Influencing factors

The factors that control shrinkage in fabrics or garments are:
• Construction: A tighter fabric construction reduces potential shrinkage
• Yarn twist: Optimum twist (based on yarn size) is very important for
controlling shrinkage and torque.
• Type of Weave or Knit: Pain weave of Jersey knit show more resistance to
shrinkage than other types.
• Tension During Sewing of Garments: Uneven or too much sewing tension can
lead to differential shrinkage causing puckering in the seam areas.
• Stability of Fiber and Yarns: Improper stabilization could lead to excessive
shrinkage especially in blends where synthetic fiber shrinks differentially than
the cellulosic fibers.
Shrinkage : Factors

Shrinkage control is based on the following factors :
1. correct knitted construction is essential
2. excessive tensions should be eliminated during processing (from grey
inspection to finishing)
3. untwisting and extraction to below 65% moisture content
4. padding the correct softener on to the fabric
5. spreading with overfeed and pre-drying to approximately 30% moisture
content
6. step by step shrinkage reduction.
Computer programs have been developed in an attempt to reliably predict the
shrinkage and dimensional properties of finished, knitted cotton fabrics using a
database of processed fabrics of known construction, processing sequences and
performance. This was given the name Starfish – start as you mean to finish!
Dry finishing processes are usually restricted to brushing (particularly for fleece
fabrics) and cropping. These processes and their associated machinery have been
discussed in section.
Shrinkage control

Compressive Shrinkage (Relaxation Method)
Used for woven cotton, tubular knit cotton, linen and rayon;
the method consists of mechanically compressing the fabric lengthwise by overfeeding
onto a large roller with damp blankets. Sanforized is a well known trade mark for
fabrics treated by this method.
Heat Set (Relaxation Method)
Used for fabrics from thermoplastic fibers such as nylon, polyester and acrylic;
it is based on the principle that thermoplastic materials will become stabilized in their
configuration in which they happen to be when heated to their softening temperature.
Finishing that Alter Durability ― Shrinkage Control

Sponging (Relaxation Method)
» Used for woolen and worsted fabrics;
it consists of thoroughly wetting the fabric with water or steam and allowing the
material to dry slowly in a relaxed tensionless state. This does not make wool
washable or shrink-proof; it permits wool to be steam pressed or caught in rain
without severe shrinking.
Resin Treatments (Relaxation Method)
» Used for fabrics of rayon and cotton;
it involves impregnating rayon and cotton with resins and then curing which
stabilizes the fabric and thus reduces its tendency to distort. Resins also provide
crease resistance. It is preferable to hand wash resin treated rayon fabrics.
Finishing that Alter Durability ― Shrinkage Control

Rubber Belt Principle
Compressive Shrinkage

Belt Principle for Imparting Mechanical Shrinkage for Knits

For open-width knit fabrics based on cavity type overfeeding
The Micrex Process
Shrinkage Control of Knit Fabrics

Construction Shrinkage:
After a cotton fabric is constructed on a knitting machine or weaving loom, it has
inherent characteristics based solely on the yarn construction variables
used.These characteristics or conditions are referred to as the greige delivered
state and can be tested for various specifications including shrinkage. The type
of shrinkage measured at this point is defined as construction shrinkage.
Construction shrinkage is defined as the amount of dimensional change in a
fabric based solely on the construction variables used to create the fabric. It
is measured after fabrication but before subsequent processes.
Construction Shrinkage

Processing Shrinkage:
All processing steps in a dyeing and finishing plant and in an apparel
manufacturing operation affect the dimensions of a product. Some techniques
have more impact than others. These steps create processing shrinkage, which
can be defined as the dimensional change that a process adds to or removes from
the construction shrinkage of a fabric, and thereby changes the residual shrinkage
accordingly. Length and width dimensions are both affected, and the fabrics may
either be stretched or consolidated. Most often, the length is stretched and the
width is reduced during wet processing. Some of this shrinkage is composed of
elastic shrinkage and can be easily recovered while some of the change in
dimensions may not be recovered, because the elastic limits of the fabric as
constructed have been exceeded.
Processing Shrinkage

Drying Shrinkage:
Drying shrinkage is defined as dimensional change in a fabric when “deswelling”
of fiber, yarn, and construction occurs in the drying step. The structure shrinks
upon itself as a result of the physics of drying.
This swelling and deswelling phenomena along with mechanical action is used in
the AATCC Test Method 135-03. The test uses a washing machine to wet out
(swell) the fiber/fabric under tensionless conditions and a tumble dryer to apply
energy in the form of mechanical tumbling with heat to deswell and fully relax
the fabric/garment. Tumble drying without restrictions (tension) is a form of
mechanical compression and allows for maximum “drying shrinkage” to take
place.
The importance of the swelling mechanism is significant. As the fabric wets out
without tension, swelling of the fibers and subsequently the yarns and the fabric
results. Upon swelling, the crimp in the yarn loops increases. In effect, the loops
in the knitted structure try to assume their lowest energy state that is a more
round configuration, which is the lowest energy state for the yarn and therefore
for the fabric. The rounding of the loop results in a shortening of the loop and
therefore relaxation and dimensional change.
Drying Shrinkage

Elastic Shrinkage:
Elastic shrinkage is defined as a change in dimensions of a fabric as a result of the ability of
the fabric to freely relax from tensions experienced during construction and other
processing. In the case of cotton greige knit goods, tensions in forming the knitted loop,
from the takedown and from spreader mechanisms on a knitting machine, are examples of
stresses that may induce elastic shrinkage, which becomes a part of the construction
shrinkage. The stress in transporting of fabric in bleaching and dyeing machines as well as
finishing operations will also induce elastic shrinkage. Normally, the recovery from elastic
stresses (realization of elastic shrinkage) is fairly spontaneous when these stresses are
relieved, especially in a dry medium.
It should be realized that because of these stresses during processing, the delivered
dimensions that were measured for the greige fabrics are no longer applicable. The
residual shrinkage has changed. In fact, the stresses involved may exceed the elastic limit
and will prevent the finished fabrics from relaxing or bulking as much as the greige fabrics.
Therefore, not only will the residual shrinkage be different, but also the relaxed dimensions
of the processed fabrics will be different from the greige fabrics. Relaxed dimensions are
defined as the state at which a fabric is fully relaxed and will not shrink further as a result of
washing and tumble drying.Relaxed dimensions are also referred to as the reference state.
Elastic Shrinkage

In today’s modern finishing plants, methods are used to attempt to overcome processing
shrinkage and reduce construction shrinkage. These methods include relaxation drying,
compaction, and/or chemical processes.Relaxation drying and compaction are examples of
consolidation shrinkage. The former occurs naturally by deswelling of the cotton fiber/yarn
assembly while applying unrestricted agitation with no tensions in the length or width. The latter
is a dry mechanical effect gained by forcing the fabric structure to compact upon itself. The
more processes of this type the mill can effectively apply along with linear forces removed from
the processing, then the lower and more consistent the amount of shrinkage.
Just as greige and finished dimensions can be measured, the dyer/finisher can also measure the
effect of each processing step on fabric shrinkage. Benchmarks for measuring dimensional
change can be applied on the greige goods and measured at each point along the processing route.
By using this technique of process monitoring, the finisher may realize and correct for any
avoidable distortion problems that may occur along the processing route. For example, if the
extraction step is shown to stretch the fabric in the length by significant amounts, then the
finisher can adjust the machinery to lower the forces applied in this process to thereby reduce the
distortion and lower shrinkage.The initial reaction of most management teams is that they cannot
afford to do this type of monitoring in their plant; however, in-plant process evaluation costs are
offset by the money they save by reducing reworks for shrinkage and also by eliminating
from consideration those constructions for processing that cannot meet customer specifications
due to their unsuitability to the processing equipment in place. An example of the effect of
processing tensions is discussed later in this bulletin.

Measurement of Fabric Shrinkage & Dimensional Stability

Shrinkage test:
Testing time: After dryer or before compacting.
Equipment used: Shrinkage board ,shrinkage scale, measurement tape, scissor,
washing machine, detergent.
 Lengthwise shrinkage = (-ve) %.
 Lengthwise extension = (+ve) %.
 Test method : ISO 6330:2000.
 Shrinkage tolerance: ±5%.
The fabric is cut according to the shrinkage board. Then the fabric is washed by
washing m/c with PCLF for 60 min. at 40. Then the shrinkage% is determined by
the shrinkage scale.
Shrinkage Test:

Determination of dimensional change in washing and drying:
International Standard ISO 5077
First edition- 1984-12-01
 Principle:
The specimen is conditioned in the specified standard atmosphere and
measured before subjection to the appropriate washing and drying procedure.
After drying and conditioning and measuring of the specimen, the changes in
dimensions are calculated.
 Apparatus and reagents: Specified in ISO 3759 and in ISO 6330.
 Atmospheric Condition: The atmospheric conditions required for pre-
conditioning and testing are specified in ISO 139.
Shrinkage Test: Determination of dimensional change in washing and drying

Test specimens:
1. The selection, dimensions, marking and measuring of test specimens
are specified in ISO 3759.
2. The number of specimens to be tested is determined by the precision of
the results required. In this test method, it is suggested that four
specimens of each sample be tested and these specimens be washed in
two separate wash loads with two specimens per wash load.
3. In certain circumstances, it may be desirable not to test four specimen
may be used.
.
Shrinkage Test: Test specimens

Working Procedure:
The sample which is done shrinkage test, spread on table. Then a glass template put
on sample fabric which is square size. There are six mark on glass template and
distance between two mark is 35 cm. Marking the sample fabric by unchangeable
marker. Then sample is sewn by hand sewing machine. Sample is ready for washing.
Simple wash the fabric at 60˚c temp for 90 min. after washing the fabric is taken out.
Dry the sample as per any of the method. It can either be Line Dry or Flat Dry or
Tumble Dry. To find the dimensional change read the Shrinkage/Stretch on 3 points on
the Wrap side and 3 points on Weft Side. Get the mean value of wrap-wise and weft
wise readings to get the Accurate Shrinkage or Stretch.
Working Procedure: Shrinkage Test

Procedure:
1. Determine the original length and width dimensions, as appropriate
after the specimens have been pre –conditioned, conditioned and
measured according to the procedure specified in ISO 3759
2. Wash and dry the specimens according to one of the procedures
specified in ISO 6330, as agreed between the interested parties.
3. After washing and drying, condition and measure the specimens and
calculate the dimensional change of the specimens according to the
procedure specified in ISO 3759
Working Procedure: Shrinkage Test

Shrinkage Template & Scale is used for finding accurate Shrinkage in
fabric and Garments.
1. Shrinkage Template & Scale also measures the dimensional
changes in fabrics after laundering, dry cleaning etc.
2. Template and shrinkage scale made up of transparent
polymer plate to apply standard pressure on test specimen.

Features of Shrinkage Template & Scale:
1. To determine directly the % dimensional change (shrinkage) in all types of
fabrics.
2. Fine calibrated Shrinkage Template with 18" x 18" & 10" x 10" benchmarks
length-wise & width-wise.
3. Two fine tipped black & yellow fabric markers are supplied for accurate
marking on light & dark color fabrics.
4. Calibrated scale to evaluate shrinkage & stretch directly Up to 15%.

How Shrinkage Template & Scale works?
1. The marking template should be placed on the specimen to be tested,
making sure that the fabric is in flat position before marking.

1. Hold the template firm, and carefully mark the fabric through the eight
slots of the template, to ensure that it does not move

Washing : Now put the fabric in the washing
machine or Dry Cleaning. Dry the sample as per
any of the method. It can either be Line Dry or Flat
Dry or Tumble Dry.
Drying : Dry the sample as per any of the
method. It can either be Line Dry or Flat
Dry or Tumble Dry.
Washing process:
 Method : ISO 6330
 Detergent: suitable detergent (0.5%)
on the weight of 1.8kg sample.
 Sample size: 62cm×62cm
 Marking area: 50cm×50cm
 Time: 45min
 Temperature: 400C
 Machine RPM: 1100

To find the dimensional change read the Shrinkage/Stretch on 3 points on the Wrap
side and 3 points on Weft Side.
Calculation for shrinkage percentage:

Shrinkage is determined as;
Shrinkage % = (length of fabric before wash)-(length of fabric after wash))/ (length
of fabric after wash) *100
Example,
length of fabric before wash = 35 cm
length of fabric after wash = 33 cm
Now, Shrinkage % = {(35-33)/ 33} * 100
= 6%
Here, Shrinkage is 6%. Normally shrinkage is acceptable less than 5%. But it can be
change in case of buyer requirement.

Shrinkage percentage = (Lo-L1) ×100/Lo
Where,
Lo = the distance between the datum line before washing and
L1 = the distance between datum lines after washing.

Expression of results:
1. Calculate the mean changes in dimensions in both the length and width
directions accordance with the arrangement in ISO 3759 as follows:
1. Express the average dimensional changes to the nearest 0.5%.
2. State whether the dimension has decreased (shrinkage) by means of a minus
sign (-) or increased (extension) by means of a plus sign (+).
Expression of results:

Get the mean value of wrap-wise and weft wise readings to get the Accurate
Shrinkage or Stretch.
Shrinkage Test result

 As already noted, shrinkage is a serious problem with knitted fabrics. Even a target
shrinkage of 5% maximum in both length and width directions is difficult to
achieve. Slit (open-width) fabrics are stentered with overfeed and without undue
stretching, then often Sanforised to reduce potential shrinkage.
 Both open-width and tubular fabrics are dried on what is effectively a continuous
open-width ‘tumbler’ dryer in which the fabric passes through the machine in a
relaxed state on a continuous belt and air is blown from jets through the fabric.
Both types of fabric can then be subjected to compacting in which the fabric is
overfed and steamed.
 It is claimed that tubular, mercerised and compacted knitted fabric can have a
shrinkage as low as 1%.
Remedies : Shrinkage

Shrinkage Tolerance of Different Fabric:
Fabric Type Length (%) Width (%)
S/J -5.50 -5.50
Lycra S/J -6.00 -6.00
Single Lacoste -7.00 -7.00
Lycra Single Lacoste -7.00 -7.00
1X1 Rib -7.00 -7.00
Lycra 1X1 Rib -7.00 -7.00
2X2 Rib -8.00 -8.00
Lycra 2X2 Rib -8.00 -8.00
Interlock -7.00 -7.00
Terry Fleece -5.00 -5.00

FOR 100% COTTON PLAIN SINGLE JERSEY
Effect of GSM on Shrinkage (Tumble Dry):
Sample
No.
Shrinkage
120 GSM 130 GSM 140 GSM 160 GSM 180 GSM
Length
wise
Width
wise
Length
wise
Width
wise
Length
wise
Width
wise
Length
wise
Width
wise
Length
wise
Width
wise
01 -6.5% -5% -4.4% -5% -3.62 -1.96 -3.32 -2.18 -2.18 -2.08
02 -4.51% -4.16% -3.74 -2.09 -3.7 -0.96 -3.17 -2.5 -2.72 -2.13
03 -5.74 -2.41 -4.15 -4.9 -3.43 -6.06 -3.37 -2.33 -2.74 -2.17
04 -4.44 -3.92 -4.22 -3.37 -3.18 -4.12 -2.94 -2.29 -1.17 -2.19
05 -4.7 -6.12 -3.75 -0.99 -3.56 -4 -3.15 -2.2 -0.72 -2.03

Fig: Effect of GSM on Shrinkage in lengthwise (Tumble Dry)

METHODS FOR REDUCING SHRINKAGE
Now that shrinkage has been defined, the factors that have an impact on
performance will be looked at in detail. There are many factors that relate to
shrinkage. These include the fiber, the yarn size and type, construction
variables, wet processes, finishing procedures, apparel manufacturing
techniques, and garment care methods.
Cellulosic fibers are not as easily stabilized as are thermoplastic synthetics,
because they cannot be heatset to attain stability. Also, synthetic fibers do
not exhibit the swelling/deswelling scenario that cotton exhibits. However, the
comfort and overall appeal of cotton has resulted in greater demand by the
consumer and by usage in the textile industry. Therefore, the relaxation of
fabrics made with cotton fibers requires either mechanical and/or chemical
means for stabilization.

Yarns, of course, are made with fibers and exhibit the same characteristics as the
fiber. Yet the manner these fibers are oriented in a yarn will affect certain
properties of the fabric including shrinkage. Cotton singles yarns of high twist
will usually yield higher shrinkage values than yarns of lower twist levels and will
certainly yield greater skewing or torqueing. Rotor spun
yarns do not typically yield significant different length shrinkage values than ring
spun yarns, but are usually wider and certainly exhibit less fabric and garment
torque. Plied yarns of either type usually yield very little skewing tendencies,
but do not impact shrinkage.
Different constructions can have significantly different shrinkage characteristics.
For example, the performance of a single pique is certainly different from that of
a jersey or interlock made from the same yarns and should be processed in a
different manner. For example, the “tuck” stitches in a pique tend to make
the fabric wider and less extensible than single jersey. Typically, pique
fabrics have much higher length shrinkage than width shrinkage.

Wet processing procedures generally exhibit stress on a fabric. Continuous processes
during dyeing and preparation for drying usually stretch the length and pull down or reduce
the width, sometimes beyond their elastic limit thereby changing the relaxed dimensions.
Finishing procedures may reduce or increase the dimensional stability of the fabric. If
relaxation dryers, compactors, and/or crosslinking agents are used, then the residual
shrinkage after wet processing can be reduced.
Apparel manufacturing processes often increase the level of shrinkage in a fabric. The
laying down of the layers for cutting and the physical manipulation of the panels in
sewing are examples of where shrinkage values can be increased. In fact, garments
comprised of different fabric constructions may have some panels relax with handling in
cut-and-sew while other panels may grow.
Garment care labeling and laundering practices will have a direct influence on shrinkage
performance. If the label calls for line or flat drying, then mostly elastic shrinkage will
affect performance. However, if tumble drying is suggested, then all available residual
shrinkage will be realized.

The best chance to achieve low shrinkage in cotton knitted fabrics is to totally
engineer the product from fiber selection through all processing steps.
The parameters for success can be outlined as follows:
1. Proper product specifications and fabrication.
2. Low tensions during wet processing (dyeing and extraction).
3. Relaxation drying.
4. Finishing with compaction and/or crosslinking agents.
5. Low tension packaging for apparel manufacturing.

Low Tension Wet Processing
Each step in wet processing applies some stress to a knitted fabric. Some processes
require that the fabric be pulled continuously through a range or cycled through a
vessel in order to get a desired effect. Jet dyeing machines, becks, bleaching ranges,
and pad and beam processing units all pull on the fabric in the length direction during
the process. Equipment manufactured today applies less stress on the fabric than did
those of only ten years ago; however, it is common for these machines to stretch
fabrics in the length. At the same time, some soft flow and overflow jet dyeing
machines actually either do not stretch the fabric or may even relax the goods in the
length. Unless it is restrained, the width of a knit fabric will relax upon wetting out in
all these vessels as a result of the tensions on the fabric in the length. In this respect, a
knit fabric acts like an accordion.
The extraction process is the single greatest area of concern for length
distortion in wet processing for knit fabrics. Strides have been made in recent years
to reduce the amount of fabric stretch in extraction; however, length stretch of 10%
and higher is commonplace.
Low Tension Wet Processing

Relaxation Drying
Relaxation dryers are available in conveyor belt systems, suction drum units, combinations
of both, and continuous tumblers. All systems make use of mechanical action during
drying to provide the energy to yield lower shrinkage. In order for a knit fabric to shrink
during drying, certain criteria must take place. The methods used to shrink the fabric must
be able to overcome the static friction that exists within the loops of the knitted structure.
Key factors for relaxation drying should include:
1. Releasing of all tensions from the fabric, especially its own weight and that of any
water it might contain at the entry of and in the dryer.
2. The use of softeners to aid fabric structure mobility by reducing the static friction
at yarn intersections.
3. Mechanical action either by air flow and belt vibration.
4. Sufficient and uniform mechanical action to overpower all static friction within the
structure but at levels low enough to prevent stretching.
5. A uniform air flow in intensity, varied in direction, but not offsetting in application.
6. Necessity to either spread the fabrics with overfeed at the entry of the dryer or to
spread at a station just before the dryer.
7. Maintaining sufficient overfeed in all drying zones to allow for complete mobility in
the fabric length during deswelling.
8. Tension free precision plaiting of the fabric for apparel manufacturing or for
the next processing step.

Compaction
During compaction, static friction is overcome by physical force. Compaction is
the use of compressive forces to shorten the fabric to reduce the length
shrinkage. This is achieved by heated roll and shoe compactors or compressive
belt systems to force the length of the loop in a knit to become not only shorter,
but also more round in configuration thereby resulting in lower length shrinkage
values. This process is a consolidation process resulting in “consolidation
shrinkage.”
Softener selection has a big impact on the efficiency of the compactor. The use
of improper softeners can prevent the compaction force from being effective by
causing slippage between fabric surfaces and machine components in the
shrinking zone. Softeners may also reduce the static friction so much that the
yarn loops may easily compact, but then lose the compaction during subsequent
processing. Corrugation or wrinkling of the surface because of improper loop
movement during compaction can be a big problem to finishers. This is a defect
usually associated with over-compaction, but it can also be caused by improper
or non-uniform softener application as well as improper moisture content at the
compactor.

Chemical Finishing
Chemical crosslinking has been the most used method for stabilizing cotton knit
apparel fabrics especially those finished in open-width form. Compaction
methods have also been effective but have been mainly used on underwear
fabrics and most tubular goods. The advent of wet processes that impose lower
tensions on fabric, such as the evolution of relaxation dryers and the
improvement of compaction machinery including open-width, have combined to
reduce the need for or level of chemical finishing.However, the desire for very
low shrinkage without the
corresponding increase in bulk experienced with compaction of a knit structure
has led to the continued use of crosslinking agents for cotton products.
Chemical crosslinking affects the swelling of cotton and reduces shrinkage
by altering the normal shrinking (swelling/deswelling) phenomena. In fact, a
well-designed crosslinking system will permanently alter the shrinkage thereby
altering the relaxed dimensions. Other benefits of a chemical finish would be a
better appearance as related to wrinkling after washing and tumble drying, less
tendency to pill or form surface fuzz from repeated laundering, and improved
color retention for some dyestuffs. The disadvantages are losses of strength and
shorter wear life.

The importance of understanding shrinkage and it causes is key to its control.
In summary, a partnership between a mill and an apparel firm is a necessity
for success in the marketplace. This is true whether the product is a national
or store brand at retail.
Mutual planning and engineering of a product is the only recipe for success. In
order to meet product specifications, the correct yarn, machine set-up, and
dyeing and finishing processes must be chosen. Arbitrary specifications and
improper choices of processing routes are a guarantee for failure in the battle
to control shrinkage for cotton fabrics.
CONCLUSIONS

Reference :
A GUIDE TO IMPROVED SHRINKAGE
PERFORMANCE OF COTTON FABRICS
ISP 1009
© 2004 Cotton Incorporated. All rights reserved; America’s Cotton Producers and Importers.
 Class lectures of Textile Physics and Textile Testing and quality
Control , Southeast university, Fall - 2013 .

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