How many traditional bleached method for 100% cotton fabric?
2015-12-07 17:47 | writer: admin
1、Sodium hypochlorite bleaching
Sodium hypochlorite bleaching craft and equipment is very simple, using for cotton fabric and cotton blended fabric bleaching, sometimes using for poly cotton blended fabric bleaching. But it cannot be using for silk/ wool such protein fiber bleaching, because it will broken the protein fiber, and make the fiber being yellow.
Because sodium hypochlorite bleaching will discharge active chlorine on the waste water, will cause non-biodegradable and adsorbed organic chloride, therefore many country have made the strictly standard for pollution. At present sodium hypochlorite bleaching craft is rarely used, just on bast fibre fabric bleaching used.
2、Sodium chlorite bleaching
Sodium chlorite bleaching is one mild oxidizing agent, on normal bleaching condition, it will not destroy the fiber, and can used on cotton/ synthetic fiber and blended fabric bleaching, but it’s not fit for spandex stretch fabric and wool or other protein fiber fabric bleaching. Sodium chlorite have efficience of rogue, especially have great ability of wiping out cotton seed, therefore it’s have lower request on pre-treatment, even without sizing can being bleaching, craft process will be short, and to poly such blended fiber also have bleaching effect, product white degree good. But sodium chlorite cost higher, and bleaching process will produce toxic and strong causticity gas, have higher request on equipment material and labor protection, having environmental pollution, as a result will have big limited, at present it rarely been used.
3、Hydrogen peroxide bleaching
It have great and stable white degree using hydrogen peroxide, applicable range widely. Not only using on various fiber bleaching, but also adopt kinds of craft such as soak/float/pressing and padding steam bleaching etc, meanwhile can treated with alkali sizing and alkali refining bathing, put these two process as one step, forming pre-treatment short process craft, and bleaching fabric white degree higher, and have been used widely on dyeing factory.
At present widely used two craft have some shortage: (1)hydrogen peroxide steaming craft need to be finished under high temperature 1 hours function, not only waste a lot of energy , and have lot damages to fiber, fabric breaking strength decreased a lot,cellulosic fiber dissolved rate higher. (2) to hydrogen peroxide cold padding craft, padding quantity/bank up time/ environment temperature and washing condition waves etc , all will have big effect to bleaching, it’s product quality stable should be promoted.