Wrinkle finishing technique (Wrinkle effect)

Apparel wash & Finishing Azmir Latif (MSc. in Textile Engineering)
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Introduction:
Resin & its use in Denim garments industry to create unique & vintage looks which add
value to denim garments & improves it sale ability in market. In 80’s we have seen Resin
being used to give non press , iron free trousers & now we are using in Denims to make
wrinkles & creases to look natural vintage which stays after multiple home laundries.
The present invention relates to processes and methods for treating Denim garments. In
particular, the invention relates to the treatment of denim made of cotton, cotton blends and
synthetic fabrics for the purpose of imparting no press properties thereto. [2]
Wrinkle finishing technique:
A wrinkle, also known as a rhytide, is a fold, ridge or crease in the cloth or garments.
Wrinkle is a particular type of pressure in the finished fabric. It is produced during finishing
operations by the thickness of the seam used to join pieces for processing. Wrinkle
resistance in a fabric is a desirable attribute, but it is not easily measured quantitatively.
Wrinkle resistance varies from quite low in many fabrics to very high in resilient fabrics. In
order to form a wrinkle, a fabric’s wrinkle resistance must be overcome. The fabric may,
however, produce strains and store potential energy that can become evident as wrinkle
recovery under suitable conditions. [1]
We may apply wrinkle finishing by two techniques
1. Tagging on whole garment
2. Pressing on specific area

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Objective of wrinkle finishing technique
1. Fashion and style purpose.
2. Popular design.
3. To create unique & vintage looks by wrinkle finishing which add value to denim
garments & improves its sale ability in market.
4. This requirement of buyer.
5. We get the whole area of the garment or partial or specific area of garment.
Flow chart of wrinkle finishing
Apparel
Apply resin
Pressing/ Clamping
Curing
Unload
Finishing
Using chemicals, Machine, Equipment & Raw material:
Material used: Resin
Machine or equipments used: Pressing machine, clip, industrial oven
for curing
Apparel types: Woven (pant/shirt) and knit (T-shirt) both

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Typical Resin treatment process for Non denim garments for Durable Press
finish:
Let’s talk about wrinkle free, durable press or crease free finish on non denim trousers. A
variety of techniques and additives have been suggested for use in the treatment of cotton
fabrics to obtain durable press properties. A typical process suggests the use of a low-
formaldehyde glyoxal resin (10%), a non-ionic wetting agent (0.2%), an amino functional
silicone (3%), a polyethylene emulsion (2%), and acetic acid to maintain pH in aqueous
solution wherein water comprises the remaining 84%. Then load the machine with the
garments prior to the addition of the liquid mix components. Once the mixture components
are added, the garments are allowed to soak for between six and ten minutes without
agitation. The offload & do hydro extract & semi dry. [2]

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[3]
Merit & Demerit of different resin application
Merit:
 By applying resin on the garments to create creases in the clothing were creases are
wanted such as pant legs and sleeves on shirts.
 Press clothing to create creases where wanted;
 By oven curing it make cross link and create the wrinkle properties on garments.
 It prevents the intermolecular slippage in the fiber core.
 If we use formaldehyde free resin, it may not harmful

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Demerit:
 It decreases the tensile & tear strength
 It decrease the abrasion resistance
 It gives an unpleasant odor
 It gives unwanted harsh & stiff feel
 It turns the fabric yellow after chlorine bleaching
 Some time difficult to remove unfixed resin
The amount of time required to reach the target moisture level will depend on the weight of
the fabric, the temperature of the dryer, the duration of the drying cycle, and the extent to
which the garments are tumbled. However, it is important to keep the drying temperature
below a temperature which will cause the resin to set. [2]
Once the garments have been dried to the proper moisture level, they are ready for the
pressing and final cure steps. It is important to press and finally cure the garments without
substantial delay, i.e. delay of more than approximately 12 to 24 hours, depending upon the
weight of the fabric comprising the garments. Denim fabrics can be held between the drying
and the pressing steps longer than lighter weight fabrics, because they tend to more readily
retain moisture. Pressing of the garments in accordance with the present invention is done
with a garment press capable of exerting a vacuum on the garment through the lower plate
of the press. Initially, the garments are positioned with the aid of a vacuum to eliminate
wrinkles and they are subsequently subjected to a steam treatment for approximately five
seconds with the vacuum turned off. Steam is then applied to the garment through the top
plate of the press for approximately 5 seconds. Finally, the garments be pressed for non
denim to get wrinkle free, durable press finish or crunched for denim where ever 3D effect
needed and cured. [2]
The current technology of post cure being introduced for non denim garments process gives
an option to produce a garment with smooth drying and wrinkle resistant properties along
with sharp creases that are durable for the life of the garment. In this process the resin
is padded onto the fabric and dried at low temperature. The fabric is then cut,

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garment constructed and creases pressed into the garment. A high temperature cure in this
configuration is given to cross-link the resin. This process, though giving excellent results,
has not been too successful with garment manufacturers owing to obvious limitations of
colors, styles and fabric weight, and the need for a direct interface between mills, garment
manufacturers and retailers. [2]
Chemicals being added to process & its functions
The non ionic wetting agent reduced surface tension of the fiber & allows chemical
penetration, so cross linking can take place throughout the fiber cross-section. A high
density polyethylene restores some of the lost tear strength and abrasion resistance by
providing lubrication. It also has a synergetic effect with silicone or fatty-based softeners to
improve hand feel. Among the silicone softeners, amino functional or reactive polysiloxanies
with silanol functional end-groups act as elastomeric finishes imparting higher crease
resistance, good dimensional stability and excellent soft handle. They can also reduce free
formaldehyde release by replacing part of the resin. [2]
Above processes and methods provides a commercially practicable method for imparting
durable press characteristics to fabrics containing cotton. Garments treated by the methods
set forth herein may be made to have durable press and softness characteristics which are
both superior and consistent from batch to batch and maintaining an acceptable level of
garment wear and durability [2]
Description
The wrinkle free finish is being done by cross-linking cotton. Permanent press finishes
function by forming cross-links between adjacent cellulose polymer chains. Then cross-
linked cotton does not allow fibers to shrink & thus wrinkles will not form. In todays’s world
DMDHEU- Di methyl Di hydroxyl Ethylene Urea is the main cross-linking agent.
With magnesium chloride as the acid catalyst to initiate a reaction, it forms cross links in the
amorphous regions of the fiber.

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There are many modified version of DHDHEU’s are available in market as tailor made
products, easy to use & with low formaldehyde. Formaldehyde release is always a big issue &
it may cause cancer to human body. Hence internationally free formaldehyde parameter
being set up to maximum 75 PPM. There are new inventions/ research being done
with no formaldehyde resin application but somehow or other it’s not so
popular either they are not as durable as resin or very high in cost to use in mass
production.
How Resin works:
Resins work by reacting the nitrogen atoms of each resin molecule with the hydroxyl group
of the cotton fabric. The reaction forms a linkage between the resin and the cotton fibers
giving the cotton on shrink pattern in which shape is being made & cured.

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[5]
Resin cross linking with cellulosic fiber

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Resins being cures in acidic pH with particular heat & temperatures. To maintain pH
catalysts can be used, as these are salts of acid. Oven curing is needed to reach right
temperature ( 145 – 160 C ) & time ( 7 – 22 min ) as per Resin tech bulletin advice.
Fabric strength loss may results up to 50 percent& it completely depends on fabric
weight, construction & fiber content. Shade change also occurs due to resin cross linking.[2]
There are two types of wrinkle process:
1. Permanent Wrinkle Process
2. Overall Wrinkle Process
1. Permanent Wrinkle Process:
 Generally permanent wrinkle is doing on garments after all types of wet process wash
in dry position.
 Permanent wrinkle is done on the garments made from all types of fabrics like,
Denim, Twill,
 Canvas, Poplin, Corduroy, Knit & Polyester etc.
 For permanent wrinkle we are use resin which is spray on garments
particular/specific area by nozzle.
 Resin is diluted with water which is recommended by chemical supplier, generally
20% resin& 80% water.
 After resin spray on respective area, then fold by buyer demand and clip attached
upon the folding area.
 Now hangers the garment in to the hanger trolley, Trolley capacity approx. 80-100
pcs garments.
 Then trolley with resin treatment garments put inside the Industrial oven.
 Set temperature 140°c to 160°c, Time 20-40 minutes (if folding layer is less,
 Less time required, if folding Layer is more, more time is required).
 Start the machine.
 When setting time is over, machines are automatically off.

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 After heating time over garments with hanger will stay 10 minutes for cold in oven.
 Now open the door and trolley with garment out from oven.
 Open the clip from garment and go to quality section for quality checking & delivery.
[1]
2. Overall Wrinkle Process:
 Generally overall wrinkle is doing on garments after all types of wet process & dry
process.
 Overall wrinkle is done on the garment made from all types of fabrics like, Denim,
Twill,
 Canvas, Poplin, Corduroy, Knit, Polyester, Viscose & Nylon etc.
 Now tie the whole garment in tight position by thread.
 For overall wrinkle, we are used resin in washing machine with water and run tied
garments for 5 to 10 minutes at 50°c temperature.
 Then unload the garments from washing machine to trolley for hydro extractor to
remove the excess water.
 Open the tie or cut the thread.
 Now hanger the garments into the hanger trolley. Trolley capacity appreciates 80-100
pcs garments.
 Then trolley with resin treatment garments put inside the Industrial oven.
 Set temperature 140°c to 160°c, Time 50-70 minutes.
 Start the machine.
 When setting time is over, machines are automatically off.
 After heating time over garments with hanger will stay 10 minutes for cold in oven.
 Now open the door and trolley with garments out from oven and go to quality section,
checking& delivery. [1]
Methods of applying Resin on the denim garments

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The major application methods currently used are based on the following processes:
garment-dip; spray application.
In the garment-dip method, garments are constructed from non-resinated fabric, then
impregnated with a resin formula similar to that used in the non denim garments process,
extracted to about 65 per cent wet pick-up and then tumble dried to 8-10 percent moisture
content, a critical factor that is determined using a moisture meter.[2]
In the spray method is a latest technology of wrinkle finishing, the resin is applied
by spraying it onto the garment during tumbling in an enclosed rotational device, or on
spray booth where garments being hanged to inflated balloons & sprayed a measured
quantity of resin solution. A microprocessor is used to meter the exact amount of chemicals
and to control the rotation time, desired wet pick-up, spray rate and process time. The
garments are then treated for different 3D effects, crunched or whatever designed intended
to produce, used for both menswear and women swear with the market moving towards
washed-down looks and softer handles.
Parameters to be considered while choosing denim
fabric for Resin finish
The garment finisher usually does not manufacture his own fabric and he may be faced with
unacceptable losses in tensile strength, tear strength and abrasion resistance in the fabric
when cross-linking. Because of the added value, garments rejects due to low strength may
prove to be more expensive than fabric rejects.
For producing an acceptable 3D effects Denim, several precautions must be taken in
fabric selection:
 The base fabric must have sufficient strength to withstand 40-60 per cent
loss in tensile and tear strength and still maintain sufficient strength to
provide a garment of acceptable wear life and durability

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 It must also have excellent absorbency to allow resin to penetrate into the
very interior of the fibres and form crosslink’s. Surface adhering resins do not
serve any useful purpose and are inefficient and wasteful
 If the fabric is dyed the dye must be fast to acid catalysis and high
temperatures. Sulphur dyes, which are known to generate acid upon storage,
are to be strictly avoided & Lycra/Spandex based fabric also should be tested
on elongation before mass production.
 Residual extractable on the fabric (like starch from size) can react with resin
and lower its effectiveness, a high degree of size removal is thus essential
 Fabric pH should be between 6.5 to 7.0.
Selection of machinery & Oven(Curing)
Many aspects must be considered when choosing the technology; type or product (Tops &
Bottoms), process, time, temperature, 3D, and chemicals.
For high quality 3D crunching / whiskers, the two most important criteria are
temperature and control of cycle. Presses should be equipped with high-heat, cast aluminum
heads or with supplementary electrical heaters to give a processing temperature of
approximately 150 – 180 degree centigrade. This temperature is crucial as it starts the
curing process and controls the effects.
There are various types of 3D making equipments available in the market i.e. Wire crinkle,
Decca/crunching machines, then aluminum flex pipes & also manmade leg hangers on
which natural 3D effects being carried out.
While selecting an Oven, garment manufacturer must analyze their products to be produced,
place/space & capacity of production accordingly they can choose from medium to big size
of batch or continuous oven which is readily available with many machinery producers.
Curing is the process to place the fabric/garment at high temperature for allowing the
chemical to carry out the reaction process. Curing is usually used for fixation process. The

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cross linking of the resin is usually taken at constant high temperature for minutes. During
curing process, the surface temperature of the fabric is critical.
A tunnel oven is faster but requires a certain amount of garment preparation and a
material handling system to and from the tunnel. Air flow pattern in these ovens controls
temperature fluctuations, movement of the garment and effect formation and is therefore
the most important selection criteria. The air velocity is finally controlled, in as much that
temperature fluctuation has been brought down to a remarkable 3 degree Centigrade over a
single garment. Developments are also underway to perfect microwave curing technology.
As against normal convection curing, the temperature rise in microwave ovens is expected to
be quicker, uniform throughout the fiber cross section, and to give minimum damage to the
fiber.
There are many Resin suppliers available in the market & they sell their products in
combination of their own recipe & even they are expert enough to suggest you right resin
combinations for your denim garments to get unique look with low formaldehyde.

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Using resin on garments is only one major danger is leaching of free formaldehyde if resin is
not cured properly due to any parameters being ignored in a process i.e. Temperature and
time.
Hence for dealing with resin application skilled man power is pre requisite.[2]
Conclusion:
The scope of apparel wrinkle finishing is very broad, especially for denim. Only innovation
products will be able to open up new market and new horizons denim industry. Resin being
used to give non press , iron free trousers & now we are using in Denims to make wrinkles &
creases to look natural vintage which stays after multiple home laundries. Customers today
have a wide range of choices and the one who produces the best quality at a high competitive
price will survive and prosper. [4] Wrinkle finishing on apparel is an innovative and
enhanced result, which is giving a vintage look. Every washing factory now produces best
and distinct apparel.
Reference:
1. http://textilelearner.blogspot.com/2012/07/what-is-wrinkle-permanent-
wrinkle.html#ixzz3SSVgq9e8
2. http://www.denimsandjeans.com/denim/manufacturing-process/resin-treatments-
giving-value-addition-to-vintage-denim-garments/#comment-7493
3. http://www.slideshare.net/legendbd71/dry-washing-on-denim
4. http://www.dry-washing-on-denim-25-638
5. Thesis on a study of the resin finishing on wrinkle property of light weight 100% cotton
plain fabric by Ho long yi.

Wrinkle finishing technique (Wrinkle effect)

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