Stone washing

Stone and denim washed garments, generally cotton, show a characteristics well- 

Cationisation of the cotton surface by a treatment with 1,1 -dimethyl-3-hydroxy-azetidinium chloride (DMA-AC) followed by dyeing with reactive dyes can develop the appearance of a denim type effect on specially constructed fabric [86]. 

The use of acid cellulases are recommended for fast treatments and neutral cel-lulases for more severe treatments when marked effects are required [56,91 ]. Endo-enriched acid cellulase is found to be best for easily weekened fabrics such as 1 inen and viscose rayon. Standard whole acid cellulases are best for sturdy fabrics sucli as lyocell, modal rayon and heavy weight cotton [92]. 

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Stone conservations Stonegroundwood Stone treatment Stoneware Stone-washing Stony coal Stop-flow ftir techniques Stopped-flow mixing Stop Scald Storage... 

Enzymatic desizing is one of the oldest nonfood appHcations of commercial amylases. Another type of enzyme, microbial ceUulases, has developed within the textile iadustry as a tool for fabric finishing, ia particular for denim garment finishing. CeUulases can achieve the fashionable worn look traditionaUy obtained by the abrasive action of pumice stones, ie, stone-washing. 

Denim Finishing. Most denim garments are treated in laundries before reaching consumers. The garments are given a fashionable appearance such as the stone-wash or acid-wash finishes. 

Stone-washing is carried out by lightweight pumice stones that are put into industrial laundry machines with the jeans. The stones mb against the denim and remove some of the dye. However, too much abrasion from stones can damage the fabric, particularly hems and waistbands. 

Enzymatic stone-washing is performed either entirely without stones or sometimes by a combination of stones and enzymes. CeUulases are used to attack the surface of the cellulose fiber, but leave the interior intact. Denim garments are dyed with indigo blue, which stays on the surface of the yam. The ceUulase partiy hydrolyzes the surface of the fiber, and the indigo blue is partiy removed. Either neutral-type ceUulases acting at pH 6—8 or acid-type ceUulases acting at pH 4—5 are used for these processes. 

A typical enzymatic stone-washing process (76) is as follows load garments into industrial laundry machine, add water, and heat to 50—60°C. Adjust pH to 6.0 with acetic acid or buffer. Desize garment with a-amylase for 10—15 min, and drain water. Add new water, heat to 55—60°C, adjust pH to 6.5—7.0, and add ceUulase. Tumble for 20—90 min, drain, rinse twice, and dry. 

Cross-linking the fibers with radiation lead to durable-stretch fabrics. The fabrics can be made by any process, such as weaving and knitting, and from any combination of cross-linked, heat-resistant olefin elastic and inelastic (hard) fibers, e.g., cotton and wool. These fabrics exhibit excellent chemical resistance (e.g., chlorine or caustic resistance) and durability, that is, they retain their shape and feel (hand) over repeated exposure to processing conditions, such as stone-washing, dye-stripping, and PET-dyeing. 

Enzymatic resolution, in oxazolidinone preparation, 17 739-740 Enzymatic stone-washing, 10 302 Enzymatic sweetener production, 10 286-287 Enzyme activity in flax fiber, 11 599... 

Enzymes in the Textile Industry Stone-washed Denims, Shiny Cotton Surfaces... 

Figure 6.2 Effect of cellulase on indigo dye on denim cloth stone-washing.

Hard green Copper Stone washings, native in Goslaria. 

Cellulases Bio-finishing, bio-polishing, anti-pilling, softness, smoothness, lustre improvement and stone-washed effects on denim... 

Use Treating denim with stone washing and other finishes. 

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