Common salt: generated by hydrochloric acid and caustic soda (HCI + NaOH → NaCI + H2O). Its chemical name is sodium chloride.
When dyeing with reactive dyes, the addition of salts can play a role in promoting dyeing. The principle is that fibers and dyes are negatively charged in the solution, which generates repulsive force. After adding neutral electrolyte salts, the salt The ionized cation is adsorbed on the fiber surface and the fiber is wrapped.
When the anion of the dye approaches the surface of the fiber, the repulsive force is greatly weakened. Adding an appropriate amount of salt in the dye bath will reduce the energy resistance due to the Coulomb force and increase the dye uptake rate. In this way, the amount of dye can be reduced and the dye The color can be deepened. As for their dosage, it depends on the coloring rate of the dye and the shade of the dyed color. Do not add too much, too much will cause the dye to precipitate and cause stains on the cloth.
Soda ash: Sodium carbonate is a kind of salt composed of strong alkali and weak acid, but under certain conditions, it can show the nature of alkali, and the purity is higher, so it is customarily called "soda ash".
Used as a reactive dyeing dye fixing agent. Reactive dyes are dyed by alkaline substances when they are dyed on cotton fibers or synthetic fibers. A dilute solution of mild alkaline sodium carbonate can be used to obtain excellent results. The dosage can be based on the color concentration And increase or decrease as appropriate.
In the dyeing of reactive dyes, salt plays a role in promoting dyeing, and soda ash plays a role in fixing. Both are indispensable!