1. Dyeing promoters:
Both sodium sulfate and salt can be used as dye promoters for dyeing cellulose fibers with direct dyes, sulfur dyes, reductive dyes, reactive dyes and soluble reductive dyes. When there is a large amount of residual dye in the dye solution, sodium sulfate or salt is added as electrolyte, which can reduce the solubility and ionization concentration of the dye in the water and promote the combination of the dye and the fiber, so as to achieve the effect of promoting dyeing.
In the dyeing of dark colors, should also be based on different types of dyes to choose a reasonable amount of sodium or salt, avoid adding too much or too fast cause the condensation of dye precipitation and the formation of color stains.
2. Slow dyeing agent:
Sodium sulfate and salt can also be used in acid dyes, cationic dyes slow dyeing agents, by reducing the absorption of dyes fiber speed, and achieve the requirements of leveling.
The principle is that sulfate and chloride ions in sodium sulfate and table salt can form an ionic bond with the amino group on the fiber at the low temperature dyeing chef stage, and then gradually replace sulfate or chloride ions and fiber with dye molecules as the temperature rises.
3. Anti-fouling agent:
The addition of sodium sulfate and salt in the post-washing of colored fabrics and printed fabrics can play a certain anti-staining effect on the white floor. Of course, the application of a large number of surface active agents, anti-staining agents (such as sodium maleic acid copolymer) can better achieve the anti-staining effect.
4. Enzyme activator:
Salt can be used as an enzyme activator for textile enzymes in printing and dyeing. For example, adding salt to amylase desiccation can improve the effect of enzyme desiccation.
However, sodium sulfate does not work because sulfate ions are toxic to enzymes in principle.