Full cotton dyeing technology

Bleaching:scouring and bleaching is the application of chemical and mechanical action to remove the impurities,fabric.The fabric whiteness,softness,good permeability,to prepare for dyeing and printing.

Contton fabric bleaching processing the main process are:the original cloth preparation,singeing,desizing,scouring,bleaching, mercerizing.

(1)the original cloth preparation:raw cloth to include the raw fabric,cloth turning (batch,box,print) and joint head.Original cloth inspection objective is to check the quality of grey cloth,discover the problem can be resolved in a timely manner.Tests include physical index and appearance defects of two.The former includes original cloth length, amplitude,weight,warp and weft density and density,strength,the latter of yarn defects,such as fabric,various classes of stains and breakage.

(2)singeing:singeing aims to burn off the surface of the villi,the surface smooth and beautiful,and prevent the dyeing, printing by villi caused uneven dyeing and printing faults.Fabric singeing is the fabric take-up speed through high temperature flame,or grazed red hot metal surface, then on the surface of the presence of chorionic villi quickly warming,and the occurrence of combustion,and the cloth body more closely,warming is slower,in an ascending to the ignition point,which has left the flame or hot metal surface,thereby to burn down,and does not damage the fabric.

(3)Desizing:textile factory in order to weaving,often on warp sizing in order to improve the strength and wear resistance.Fabric slurry that affect the absorbent fabric performance and product quality,but also increase with the drug used in scouring,before removing the slurry,this process is called desizing.fabric slurry using alkali desizing,desizing, desizing enzyme acid and oxidizing agents desizing method,from the fabric stripping.Alkali desizing and allowing the slurry to expanded,and fiber adhesion force decreased,washed from the fabric stripping.Enzyme, acid,oxidative agent to make the starch degradation,increasing solubility in water,washed to remove.Due to the acid oxidant on cotton fiber damage,rarely used alone,often with the enzyme desizing,alkali desizing joint use.

(4)boiling:cotton fiber growth,natural impurities (pectin,waxy substance, nitrogen-containing substances) together with the associated. Cotton fabric after desizing,the majority of slurry and some natural impurities have been removed,but there are a small number of slurry as well as the most natural impurities residues in fabric.of these the presence of impurities,so that the cotton weaving cloth than yellow,poor permeability.Effects of cotton fabric appearance quality.So it is necessary to remove residual impurities.Scouring is the use of caustic soda and other scouring agent and pectin,waxy substance,nitrogenous material, cottonseed shell chemical degradation or emulsification,expanded role, after washing the impurities from the fabric stripping.

(5)bleaching:cotton fabric bleaching by scouring,because the fibers and natural pigment,its appearance is not white,used for dyeing or printing, will affect the color brightness.The purpose of bleaching is the removal of pigment,endows the fabric necessary and stable brightness,while the fiber itself is not subject to significant damage.Cotton fabric bleaching method has nitrogen acid sodium,hydrogen peroxide method and sodium chlorite method.

(6)mercerized:mercerized cotton fabric is refers to under room temperature or low temperature,the warp and weft directions are the absence of tension,with concentrated caustic soda solution,in order to improve the properties of fabrics processing.Cotton fabric after mercerizing,due to fiber puffed,fiber longitudinal natural torsion vanishes, cross section of light into an oval,reverse more regularly,thereby improving gloss.

By Le Qi