Difference between pre - shrinkage, washing and sand washin
The process of reducing shrinkage by physical means after immersion in water, also known as mechanical preshrinking. Preshrinking is mainly to control the warp shrinkage rate of fabrics. The warp shrinkage rate of fabrics before pre-shrinking is generally 7~8%. After pre-shrinking, the warp shrinkage rate of fabrics is generally required to reach national standard 3% or American standard 3%.
Second, the water
Wash is to add softener or detergent in water, give fabrics next time water directly, according to catharsis time and softener how many, divide commonly light general washs, general washs, heavy general washs. The effect of washing is that the fabric becomes very soft, very tactile, and there is an illusion that the fabric has thickened.
Three, sand washing
The craft that the word that arenaceous wash and wash is about the same actually, but the thing that adds is different, it is to add alkalescent or oxidizing sex to aid commonly, also can add right amount of of course a few softener. And add alkalescent assistant is to destroy the organization of fabrics surface namely, the fabrics after making arenaceous had been washed feels softer, next the surface layer of fabrics can rise a few nap, still can have a light white mist. Therefore, after sand washing, the fabric will become soft and fluffy, and the fabric will have the illusion of thickening. However, such fabric is easy to be split and may be broken with a gentle pull. We generally do not recommend sand washing thin fabric.