Views: 0 Author: Site Editor Publish Time: 2021-08-03 Origin: Site
①The soaping must be carried out at a high temperature above 95℃.
This is because, under high temperature conditions, the floating dye molecules attached to the inside and outside of the cotton fiber have greater activation energy and greater solubility, and it is easier to overcome the affinity with the cotton fiber, and desorb and dissolve into the soap solution. Therefore, the soaping effect is better.
②The soap lotion must be neutral.
This is because the bond between reactive dyes and cotton fiber has a stability problem under high temperature acidic or alkaline conditions.
Practical research shows that both the vinylsulfone group-fiber bond or the s-triazine group-fiber bond are the most stable in a neutral bath. Because: vinyl sulfone-fiber bond is poor in alkali resistance and is easy to be hydrolyzed and broken in a high-temperature alkaline bath; s-triazinyl-fiber bond is poor in acid resistance, and it is easy to hydrolyze and break the bond in a high-temperature acid bath. The reactive dyes with mixed double reactive groups have complementary effects due to the coexistence of two reactive groups, so the acid and alkali resistance stability is relatively good. As far as cotton and nylon fabrics are concerned, not only cannot "alkaline soaping", but also "acid soaping", because this will cause serious stains on nylon. Therefore, before soaping, the alkaline agent must be washed with warm and hot water, and acetic acid is not suitable for neutralization.
③ Chelating dispersant must be added to soaping.