The dyeing process of sulfur dyes

The dyeing process of sulfur dyes

Sulfur dyes are generally only used to dye dark cotton fabrics such as black and dark blue, but the market for sulphur dyes is still stable, and the research on sulphur dyes still has a certain value.

1) The dyeing process of sulphur dyes is the reduction and dissolution of sulphur dyes (using sodium sulfide as a reducing agent); the dyes in the dissolved state are dyed on the fibers (the other salt plays a role in promoting dyeing); the dyes are oxidized and fixed on the fibers; fixation and prevention Crisp handling. The reduction and dissolution of sulfur dyes should be sufficient, and the adding speed should be slow and uniform. After adding the dye, boil and dye for 10 minutes, Fang Diao slowly and evenly add salt to promote dyeing. Be sure to wash and cycle to clean after dyeing. After dyeing, the temperature cannot be suddenly cooled to prevent "bird paw prints". Anti-brittle treatment and dyeing softener are added at the same time.

2) The dye auxiliaries for dyeing with sulfur dyes are alkali sulfide, which is a highly reducing alkali agent. During the dyeing process, it is a reducing agent for sulfur dyes, reducing and dissolving sulfur dyes, but it is stable Inferior, it is easy to absorb water in the air and be oxidized by damp, so that its strength is reduced. Sulfur black is a dye that cannot be directly dissolved in water. After being dyed, it becomes an insoluble dye and solidifies on the fiber after oxidation. Sodium sulfite is a weak reducing agent, which can dissolve the free sulfur generated during the dyeing process and prevent sulfur white spots.