denim treaments

7/31/2019 Denim Treaments

1/45

-Akhil TyagiMoumita MaityNeha PandeyPulkit Mishra


2/45

Denim (which gets its name from the French town of

Nmes (de Nmes)) is a rugged cotton twill textile, inwhich the weft passes under two (twi- "double") or morewarp threads.

In a twill weave, the fabric is constructed by interlacing

warp and filling yarns in a progressive alternation whichcreates a diagonal effect on the face, or right side, of thefabric and has a surface of diagonal parallel ridges.

In some twill weave fabrics, the diagonal effect may alsobe seen clearly on the back side of the fabric. Due to thedenim's right-hand twill construction, one colorpredominates on the fabric surface. Also, because of thisway of weaving the threads to make the fabric, the fabricis very strong and durable.


3/45


4/45

Denim fabric is unique in it's connection with one color- blue. The blue, or indigo, yarn in denim fabric is the"warp thread" The white yarns are the filler thread or"weft thread".

The warp yarn is traditionally dyed with the bluepigment obtained from indigo dye. Indigo was the mostsignificant natural dye known to mankind until theintroduction of synthetic dyes, at the end of the 19thcentury. The durability of indigo as a color and it's

darkness of tone made it a good choice, when frequentwashing was not possible. In 1890s, indigo was nolonger needed synthetic dye processes wereperfected.


5/45

The yarns have a very hard twist for durability, butthis construction feature affects color also. Theyarns are twisted so tightly that the indigo dyedoesn't always penetrate, leaving the core of thefabric white. As the fabric abrades or wears awayduring use, the white cotton yarn surfaceappears, giving denims a lighter or medium bluecolor.

Contemporary or modern-day jeans aresometimes dyed in the fabric stage. These jeanshave colored yarns in both directions and tend toretain their deeper color throughout the life of the

garment.


6/45

Most jeans are made from 100% cotton ora blend of 50% cotton and 50% polyester.Other blends of cotton and polyester areavailable. Nylon is sometimes blended withcotton for reinforcement and durability.Spandex yarns are added for stretch and

comfort.


7/45

The presence of cotton contributesabsorbency and comfort. The fabric alsotends to soften with wear and laundering,giving the feel of well-worn blue jeans.

Polyester contributes durability, stability orshrink resistance, and wrinkle resistance.

Ease of care in laundering, as well as shorterdrying times result from the presence ofpolyester fiber. Many dyes used withpolyester are very stable and retain the rich

blue/black color through repeated washings,more so than dyes used for 100% cotton.


8/45

Mechanical washes Stone wash

Microsanding

Sandblasting Machine sanding

Hand sanding

Chemical washes Denim bleach Enzyme wash

Acid wash


9/45


10/45

MECHANICALWASHES


11/45


12/45

In order to stone wash jeans,the original way, they arewashed with pumice stones.Since the pumice stones have

a rough surface they scrap offa layer on the denim so thatsome of the white threads fromthe cloth become more visible,causing the jeans to appear

naturally worn. In the process of stone

washing, freshly dyed jeansare loaded in washingmachines with pumice stone or

volcanic rock.


13/45

Stone-washing the denim with pumice stones has somedisadvantages. This method is very hard on the denimfabric, as stones could cause wear and tear of the

fabric, also it creates the problem of environmentaldisposition of waste of the grit produced by the stones.

High labor costs are to be borne as the pumice stonesand their dust particles produced are to be physically

removed from the pockets of the garments andmachines by the laborers.

Denim is required to be washed several times in orderto completely get rid of the stones.

The process of stone-washing also harms big,expensive laundry machines.

Water pollution during disposal of used liqour.


14/45

A new process of stonewashing has been introduced called Perlite.

Perlite is the form of naturally occurring silicon rock.

It has the distinctive property of expanding to 4 to 20 times its initialvolume when heated at a particular temperature.

This happens because the raw perlite rock consists of 2-6% of watercontent in it. The crude perlite rock when heated at the temperatureabove 870C, it gets swollen up and tiny glass sealed bubbles areformed.

Its original color which is black or gray changes to grayish white elsewhite.

This heated form of perlite is used for stonewash purpose.

It gives throughout uniform worn out and old look to the denim.


15/45

A fabric finishing process wherefabrics are sanded (real sandpaper)to make the surface soft withouthair.

Can be performed before or afterdyeing.

In this fabric treatment process, aseries of cylindrical rolls in ahorizontal arrangement, eitherwrapped with an abrasive paper or

chemically coated with an abrasiveare used to create a soft, suededhand. The denim is pulled over theface of the sand rollers creating araised surface finishing.


16/45

There are 3 ways for this technique: Sandblasting

Machine sanding

Hand sanding or hand brushing


17/45


18/45

Based on blasting an abrasive material in granular,powdered or other form through a nozzle at very highspeed and pressure onto specific areas of the garment

surface to be treated to give the desired distressed/abraded/used look.

Although the purpose of this is generally for aesthetics,

this process also loosens the fibers in the denim, makingthe denim fit more comfortably and move more easily.

However, it is very labor intensive to sand finish denim,therefore a pair of jeans that has been sand finished willusually be slightly more expensive than one that has not.

It is a water free process therefore no drying required.


19/45

Sandblasting can be extremelydamaging to workers health if

performed without suitable protectiveequipment. The large amounts of silicadust generated during the process cancause silicosis, a potentially lethal

pulmonary disease, as workers inhaleof tiny particles of silica.


20/45

Control on the abrasion

Different look on thegarment can beachieved.

All are dry process.

Economical, ecologicaland environmentalfriendly.


21/45

Manual Brushing Machine

Robotic brushing machine


22/45

Whiskering Water jet fading Super stone wash Ice wash Thermo denim Laser technology finish


23/45

Whiskering Crease lines around the crotch. Also used for 'knee

whiskers' (whiskers on the sides of knees) and

'honeycombs(crease marks on the back of theknee)

Water jet fading Hydrojet treatment involves exposing one or both

surfaces of the garment throughhydrojet nozzles.Super stone wash

Prolonged stonewashing, up to six hours or more.

Ice wash Ice washing in denim fabrics is done to remove

more than half the dye during washing. Achieved bydry tumbling with pumice stones soaked withbleaching agents to produce a 'snow pattern effect

on denim.


24/45

Thermo denim

Also called double denim. Alightweight fabric (either plain,fancy or colored) is glued to thedenim. The glue comes off afterwashing and the trousers look like

they've been lined

Laser technology finish It is a computer controlled process

for denim fading. This technique

enables patterns to be createdsuch as lines and/or dots, images,text or even pictures.

Also called spray painting in

denims.


25/45

CHEMICALWASHES


26/45

In this process, a strong oxidativebleaching agent such as sodiumhypochlorite or KMnO4 is addedduring the washing with or withoutstone addition.

Care should be taken for thebleached goods so that they shouldbe adequately antichlored or afterwashed with peroxide to minimizeyellowing.

When desired level bleachingreached the time span available tostop the bleaching is very narrow.Due to harshness of chemical, it maycause damage to cellulose resultingin severe strength losses and or

breaks or pinholes at the seam,pocket, etc.


27/45

An enzyme is a biological chemicalcompound that reduces complex organiccompounds to simpler compounds. This isimportant to the enzyme wash because one

of its main selling points is that it is differentfrom other types of denim finishes because itis organic and non-harmful to theenvironment.

A reason that enzyme washing is soecologically friendly is the natural origins ofenzymes biodegrade rather than lingering inthe water supply in the environment


28/45


29/45


30/45

Cellulase enzyme is classified into twoclasses: Acid Cellulase: It works best in the pH range of

4.5-5.5 and exhibit optimum activity at 50. Neutral cellulase: It works best at pH 6 however

its activity is not adversely affected in the range ofph 6-8 and show maximum activity at 55 C.


31/45


32/45

An acid wash finish treatment createssignificant contrasts in the color of thedenim material. As the randomly faded,

acid washed style came into vogue in1980s, the process of treating denim insuch a way began to become increasingly

refined.


33/45

The method uses salts hypochlorous acid, which arealso known as hypochlorites. Sodium hypochlorite isthe most commonly used salt and is created by taking

sodium hydroxide solution passing chlorine into it.Another method exposes sodium chloride toelectrolysis. The resulting solution of hypochlorites areused as bleaching agents in household cleaners,

disinfectants, and especially in the textile industry dueto the strength of their oxidizing and whiteningproperties.


34/45

In order to create the random, irregular, patched and shaded,acid wash look, the dry denim cloth is first bleached. Thematerial is then put into a rotating drum in close proximity withgranulated pumice soaked with the prepared hypochlorites.This process fades the cloth both chemically, through

bleaching, as well as mechanically, as the rough granulesscrapes the fiber. After tumbling together for some time, thegranules are removed and the cloth is washed and dried inorder to neutralize any left over hypochlorites.

Acid washed, indigo dyed denim has a tendency to yellow

after wet processing. The major cause is residual manganese due to incompleteneutralization, washing or rinsing.


35/45

Rinse washOzone fadingSnow washFlat finishOver dyeSun washing

Super dark stone


36/45

Rinse wash Chemically bleaching jeans so that the color fades

away Breaks down the fibers of jeans and creates white

streaks or spots on denimOzone fading

Bleaching of denim garment is done in washingmachine with ozone dissolved in water.

Indigo dyestuff tends to fade or turn yellow due toozone reaction.

Snow wash Denim treated with a variation of acid wash that

imparts bright white highlightsFlat finish

An even wash down effect and very clean surfaceoriginally by using liquid ammonia, but now bymercerization plus calendering processes to achievethe flat surface.


37/45

Over dye Dyeing over the fabric or jeans to add another

tone of color

Most often used is a 'yellowy' overdye to create a

'dirty' lookSun washing

A very light shade by bleaching and stoning

Looks as if the sun faded the fabric

Super dark stone Commercial term for an extra dark indigo color.

Results from a double-dyeing technique


38/45

Teflon is part of advanced stain repellent technology

that provides excellent protection against liquid spillsand stains. Teflon, also known asPolytetrafluoroethyhlene, was discovered in 1938 bythe DuPont Company in their Jackson laboratory andis at the forefront of stain resistant innovations.


39/45

The molecular make-up of chemicals binds around theindividual cotton fibers instantly repelling oil and waterbased stains and releasing ground in dirt and naturalstains during the laundering process. The moleculesthat make up Teflon are hydrophilic or water lovingand they attract water and detergent into the fabric,liberating the stains into the wash leaving the fabriclooking bright and clean. This new technology forrepelling stains uses "nano-whiskers" that are adheredto the individual fibers and cause liquids to bead or roll

off of the surface of the fabric. The stain does notadhere with the fibers and therefore soiling is minimal.


40/45


41/45

Storm Denim is a technology that was created to useas a garment finish on denim that would make thefabric water repellant.

Water repellant apparel has already been heard of,however on those pieces of apparel water repellanttechnology has only been used as a fabric finish. Thismeans that is was a chemical finish that was firstapplied and after that process may have gone throughother garment finishing processes. The unique design

of Storm Denim lets its technology be the last finishto the denim allowing it to show its features in itshighest ability.


42/45

Inadequately organized garment sector Lack of technical Know How ,scarcity of trained labour ,

unavailability of superior machineries High dependency on manual operation affecting the production

,labour cost and quality standards Batch to Batch variations and garment to garment variations Poor process control ,prioritizing the cost over quality , low training

imparted to workforce and poor quality standards been adopted . Requires technological knowledge and artistic skills Top Loading machines v/s Front loading machines in terms of

utility consumptions Outsourced dry finishing v/s Inhouse dry finishing & Automation

v/s manual operations Environmental issues recycling of waste water, recovery of

Indigo Sampling v/s bulk dyeing and finishing


43/45

In todays scenario, most industries have doneaway with pumice stones and conventional sandblasting, all effects are achieved by appropriaterecipes of chemicals and enzymes, in largelaundering machines, followed by drying inpowerful hydro extractors.

Smoothening out the denims manually to imitate ahuman form with sandpaper after sewing iscommon practice.

Brands carefully guard their recipes as tradesecrets.


44/45

http://pautextile.wordpress.com/2010/08/07/denim-washing-process/

http://blogspot.com/2010/09/swagger-bleach-

denim-jacket.htmlhttp://katiechutzpah.blogspot.in/2010/05/marni

-and-vivienne-westood-collaborate.htmlhttp://www.selectism.com/news/tag/teflon/Project report on Denim Washes by Preston

University


45/45

denim treaments

Documents