How many method for cotton fabric pretreatment desizing craft ?

2015-11-24 16:39 | writer: admin

The sizing agent for gray fabric is came from Textile factory, to improve yarn’s weave property, it needs to be added that sizing agent on yarn. Traditional sizing agent have natural starch size and chemical size PVA/PMA/CMC etc. starch sizing have it’s great advantage of natural green eco property, and it gradually become the main sizing agent. 
Sizing agent ‘s exist have some difficult such as permeate resistant, dyeing chemical material waste, effect follow-up processing and product quality etc, therefore eliminating the sizing process is necessary. Eliminating the sizing process is desizing, desizing have enzyme desizing/alkali desizing/acid desizing/oxidizing agent such multiple method.
1、enzyme desizing
This method is using the amylase as the main reactant. Amylase can catalyze starch macromolecular chain hydrolysis, hereby it will generate low molecular compound with smaller molecular weight, lower viscosity, higher solubility, then going through washing , it will eliminate starch sizing . amylase’s transition percent conversion, dissolve speed, fit for continuity production, with high efficient, desizing rate reached to 80% up.
2、alkali desizing
This method is using sodium hydroxide as the main reaction. Sodium hydroxide cannot using starch dissolved, but it can make the starch puffing severely, make the intermolecular distant enlargement, structure loosen: meantime it will also make the starch and cotton fiber ‘s hydrogen bond among hydroxyl destroyed, thereby making the adhesive force of starch on cotton fiber decreased, provide it’s dissolution ability away from cotton fiber, make it’s water solubility increased, then going though water wash, the starch will be eliminated.  
3、acid desizing
This method using acid and alkali as the main reaction agent. Dilute sulphuric acid will cause water dissolution under suitable condition, and translate to solubility starch, saccharides mixture, these water dissolution component ‘s water solubility higher, based on from cotton fabric washing. Usually pad-batch process desizing agent made from vitriol and surface reactive agent. Acid desizing fiber have certain damage.
4、Oxidizing agent
This method is using hydrogen peroxide/sodium hypochlorite and peracetic acid as the main reaction agent. Oxidizing can make the sizing agent oxidative degradation, not only make the water solubility increase, but also the lotion vicidity decrease, and it’s easy make the sizing wiped off. Hydrogen peroxide /sodium hypochlorite and peracetic both are powerful corrosivity oxidizing agent.

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