Denim washing is a finishing process that adds value and creates special appearances. There are chemical and mechanical washing methods. Chemical methods include enzyme washing, acid washing, and bleaching which use chemicals like enzymes and acids to break down indigo dye for color effects. Mechanical methods like stone washing use abrasive materials like pumice stones to create worn effects. Other techniques are sand blasting, whiskering, and laser treatments. Process parameters like chemical concentration, stone quantity, and treatment time affect the results. Washing adds value but also has costs for chemicals, machinery, and labor.

1. DENIM WASHING(A value addition process) Submitted to- submitted by- Mr. Vasant Kothari Mr. Harmendarkothari M.F.Tech-2

2. Contents Introduction Types of washes Chemical washes Mechanical washes Cost References

3. 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.

4. On the base of chemical use

5. On the bases of water use

7. It attacks on 1,4-beta-glucoside bond of cellulose molecule e.g. Denim ax PB/BT

8. optimized pH and temperature = maximum activity of the enzyme

9. 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

11. incomplete reduction gives create problemRemedy: Manganese is effectively removed during laundering with addition of reducing agent(sodium bisulfate,1-5gpl, 50 deg. Cent.,20mins) -

13. KMnO4

15. On bleach liquor quantity

16. On temperature and

17. On treatment time.Drawback- Harmful to human health and causes corrosion to stainless steel.

19. Technology in based on a Laccase(a redox enzyme using mol. Oxygen as electron acceptor) and mediator.

21. B. Mechanical washes- 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

22. Recommended Specification for Stones-Moisture content-less than 5%Surface properties-less than 5% finesApparent Density-0.5-0.75gm/cm3Abrasion loss-35%Impurities –when exceed 10% they increase apparent density1 gm/cm3, the stone will not float in water during process.

23. 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 look process

24. 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 honeycomb Whiskers on skirt

25. Other mechanical washes-

26. Laser technology grinding Scrubbing Tagging on pockets

27. Costing-

28. 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