1. Substantivity of dyes
Substantivity of dyes is the main factor affecting the dye-uptake. Generally, the fixing rate of reactive dyes increases with the increase of substantivity of dyes. The substantivity of reactive dyes is generally low. Therefore, to increase the substantivity of reactive dyes, it is not advisable to dye under too high temperature and pH, because as the dyeing temperature increases, the substantivity of reactive dyes decreases.
2. pH and temperature of dyeing
The main factors affecting the reactivity of reactive dyes are dyeing temperature and pH. Generally, when the temperature and pH of dyeing bath rises, the reactivity of dye intensifies. But at the same time, excessively high temperature and pH can also accelerate the hydrolysis of dyes and reduce fixing rate.
3. Dyeing time
The dyeing of reactive dye includes two stages: dye uptaking and fixing. Lengthening the time of uptaking can enable the dye to fully diffuse and penetrate and increase the dye-uptake, which is conducive to leveling dyeing.
4. Adding electrolyte
In the dyeing process of reactive dye, adding an appropriate amount of neutral electrolyte to promote dyeing is helpful to improve the color fixing rate. It is because that adding neutral electrolyte can decrease the electrokinetic layer potential on fiber surface and increase the substantivity, so as to increase the fixing rate.
5. Dyeing bath ratio
The substantivity of reactive dye is low. When dyeing by exhaust process, small bath ratio is conducive to improving the dye-uptake. And it can increase the probability of the reaction between dyes and fibers, reduce the hydrolysis of dyes and improve fixing rate.
23119 Dispersing Leveling Agent
Post time: May-07-2026