Before dyeing and printing, textiles need to undergo a certain scouring process to remove impurities and oil stains on the cloth surface. This scouring process is usually called scouring. All kinds of chemical additives with functions of penetration, emulsification, washing, dispersion and wetting added in scouring are called scouring agents.

The function of scouring agent is to help the alkali liquor penetrate into the fiber, promote the saponification of wax and the decomposition of cottonseed shell, protein and pectin, so as to disperse the impurities separated from the fiber in the scouring liquor and prevent it from attaching to the fiber again. Therefore, a good scouring agent should not only have a good ability to reduce the surface tension of the solution and quickly penetrate into the fiber, but also play a role in saponification, emulsification and dispersion of the natural impurities on the fiber.

The main agent used to remove cellulose co-organisms (oil wax, pectin, lignin, pigment, cottonseed shell, etc.) is caustic soda, part of which is absorbed by cellulose, and part of which is used to decompose protein, saponify oil, neutralize amino acids, fatty acids and polysaccharide acids. It is required that the scouring agent must have excellent wetting, emulsifying and dispersing effects to promote the scouring effect of alkali agent on cotton; It also requires strong penetration at low temperature, high temperature and strong alkali resistance, oxygen bleaching resistance and strong washing power. Therefore, the specific requirements for scouring agents can be summarized as follows:

(1) High temperature and strong alkali resistance.

(2) It can wet the fabric evenly and quickly at room temperature, and also has alkali resistance stability.

(3) Good emulsification can remove fiber co-organisms and foreign oil from the fabric through the saponification of caustic soda and the emulsification of scouring aids.

(4) It has certain metal complexing ability, can complexe with Ca2+, Mg2+and other metal ions, remove from the fabric, and prevent the decomposition products from depositing on the fabric again.

(5) The scouring agent is required to be low foam type.

(6) It can be biodegraded, and the decomposition products do not contain toxicity.