DENIM WASHING(A value addition process)
Submitted to- submitted by-Mr. Vasant Kothari Mr. Harmendar kothari M.F.Tech-2
Contents
I. IntroductionII. Types of washesIII. Chemical washesIV. Mechanical washesV. Cost VI. References
Introduction
• Denim washing is know as one of the finishing treatment that has vast usage because of creating special appearance and updating clothes
• There is different methods of denim washing.
Types of washes
Mechanical washes
Stone wash
Whiskering
Sand blasting
Chemical washes
Enzyme wash
Bleach wash
Acid wash spray
On the base of chemical use
Types of washes
Dry wash
whiskering
Laser technology
Damage
Grinding
scrubbing
Wet wash
Stone wash
Enzyme wash
Bleach wash
PPC spray
Tinting
Acid wash
On the bases of water use
A. Chemical washes-
1. Enzyme Wash(Bio Stoning)- Cellulase enzymes are natural proteins which are
used It attacks on 1,4-beta-glucoside bond of cellulose
molecule e.g. Denim ax PB/BT
Cellulase enzyme
Acid cellulase Neutral cellulase
optimized pH and temperature = maximum activity of the enzyme
2. Acid Wash- It is done by tumbling the garments with pumice
stones presoaked in a solution of sodium hypochlorite or potassium permanganate for localized bleaching resulting in a non uniform sharp blue/white contrast.
Results depends on:--Fabric -chemical used(conc.)-Stone(quantity) -machine used
Limitations of acid wash: Tendency to be yellowish incomplete reduction gives create problem
Remedy: Manganese is effectively removed during
laundering with addition of reducing agent(sodium bisulfate,1-5gpl, 50 deg. Cent.,20mins)
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3.Denim Bleach- To decolorize the dark shade into light shade by
destroying indigo. INDIGO --------------------------. ISATIN (oxidative bleaching agent)Chemicals- sodium hypochlorite KMnO4Hydrogen peroxide
Discoloration produced is usually more apparent depending :-
On strength of the bleach liquorOn bleach liquor quantityOn temperature andOn treatment time.Drawback- Harmful to human health and causes corrosion to
stainless steel.
3-E Bleaching concept for denim-
Bleaching with sulphiric acid derivatives, and recently with laccase(enzyme).
Technology in based on a Laccase(a redox enzyme using mol. Oxygen as electron acceptor) and mediator.
eg. DeniLite(enzyme + PPT)
Other chemical washes-
RINSE WASH
Ozone fading
Over dye- tinting
Sun washing
Quick wash denim
Water jet fading
Vintage etc.
B. Mechanical washes-
1. Stone washing- Pumice stones give the additional effect of a faded
or worn look
• Stone wt. /fabric wt. = 0.5 to 3 /1• Dia.of stone-1-7 cm
Pumice stone
Recommended Specification for Stones-
Moisture content-less than 5%Surface properties-less than 5% finesApparent Density-0.5-0.75gm/cm3Abrasion loss-35%Impurities –
when exceed 10% they increase apparent density1 gm/cm3, the stone will not float in water during process.
2. Sand blasting:- Sand blasting technique is based on blasting an
abrasive material in granular, powdered or other form through a nozzle at very high speed and pressure onto specific areas of the garment surface.
product lookprocess
3.Whiskering-(Cat's Whiskers) Industrially done with laser, sandblasting, machine
sanding, hand sanding and rods.• 'knee whiskers' -whiskers on the sides of knees • ‘honeycombs' -crease marks on the back of the knee
Whiskers on skirt
honeycomb
• Other mechanical washes-
LASER TECHNOLOGY
SUPER STONEWASH
Scrapping
Grindings-
grinding
Laser technology
Scrubbing
Tagging on pockets
Costing-WASH COST($)
Whiskering .40
scrapping .35
Tagging .15-.30
Damage .10 -.50
Sand blasting(band)
Silicosis( Levi’s and H&M)
Pocket edge & hem grinding
.10
WASH COST($)
Enzyme wash .70
Acid wash 1 $
Enzyme stone Bleach wash
.95
Tieing- 0.15
Stone wash .70
PPC spray .25
Tinting .10
Laser technology 1$
Ozone wash- 3 min-0.20 30 mins-0.60
Enzyme stone wash .85
1.www.fibre2fashion.com2.Washing Report of Arvind Mills3.Denim garment washing process-ATIRA4.Denim garment processing –Express Textile(march 2003)5.Garment washing & finishing- Pearl Academy of Fashion