Sodium chlorite and sodium chlorite bleaching bleaching of cotton fabric for maximum advantage without damaging the fibers of the conditions, can damage the pigments and impurities. Sodium chlorite is a good chemical bleaching agent, bleaching whiteness stability than chlorine bleaching and oxygen bleaching of the fabric is good, but the more expensive sodium chlorite, metal corrosion, needed titanium metal or titanium alloys and other materials, and toxic sub-bleaching process of ClO2 gas, equipment, the need for a good seal, and therefore are subject to certain restrictions on the use of currently used for polyester-cotton blended fabric bleach. Asia bleaching and chlorine bleaching and oxygen bleaching difference is bleached under acidic conditions, the reaction under acidic conditions is more complex, this time more easily produced by decomposition of sub-acid to produce a product of some bleaching effect, it was considered of which the presence of chlorine is necessary for bleaching. Chlorine dioxide is a yellowish green gas, chemical nature of the lively, both bleached and dissolved the role of lignin and pectin, and greater ability to remove cotton seed shell, so sub-bleaching of the pre-treatment do not ask, and even fabric without back pulp can be bleached, process route is shorter, and particularly suitable for synthetic fabrics. But not through direct sub desizing scouring bleaching of fabrics, general poor water absorption, in the bleaching solution by adding appropriate amount of non-ionic surfactant can increase the fabric water absorption. Asia through an oxygen bleaching after bleaching, the whiteness and water absorption are increased. If the fabric in the first desizing, scouring and bleaching and then to Asia, could be appropriate to reduce the amount of sodium chlorite, but the process longer.
Asia-bleaching is bleaching in acid bath, acid strength of the sub-acid decomposition rate will have significant impact, directly enhanced the acid on pH value is inappropriate, the general joined the active agent often used to control pH, commonly used activator are: acid releasers such as inorganic salts; bleaching process can be oxidized into acid substances such as formaldehyde and its derivatives, four of six methyl bromide; hydrolyzed to form acid esters such as diethyl tartrate; also available weak acid such as acetic acid, formic acid. In addition, adding some buffer, such as pyrophosphate, can increase the stability of sub-bleaching solution, to avoid low pH, chlorine dioxide escaped from time to time.
Asia-bleaching process with oxygen bleach used is similar to continuous rolling width can be steamed method can also be used under the equipment in cold bleaching. Asian drift continuous rolling process steam method is as follows:
Bleaching liquid steamed rolled → → → water washing → to chlorine washing.
Polyester-cotton blended fabric bleach bleach sub-acid with sodium 12 ~ 25g / L, ammonium sulfate (activator) 5 ~ 10g / L, Peregal O 5 ~ 10g / L, at room temperature rolling, bleach, 100 ~ 102 ℃ steam Steam l ~ 1.5h, washed in sodium bisulfite (1.5 ~ 2g / L) and sodium carbonate (1.5 ~ 2g / L) solution immersed rolled, stacked full after washing.
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