Sulfide dyes are widely used in dyeing machine dyeing of cellulose fibers. What should be paid attention to in dip dyeing process?

1. Dyeing bath ratio

The bath ratio is related to the dyeing equipment and the depth of dyeing. The light bath ratio can be larger and the dark bath ratio can be smaller.

2. Dyeing temperature

In addition to bright colors, most dark varieties adopt boiling dyeing or near boiling dyeing. The leucosomes of some sulfide dyes (such as sulfide blue) are easy to oxidize prematurely, resulting in defects such as red tendons, color spots, color darkness and so on. It is better to control the dyeing solution temperature at 50 ~ 60 ℃, and the sulfurized color is generally 65 ~ 80 ℃, but the dyeing temperature is too low, and the diffusion and penetration of dye leucosomes are poor, which affects the dyeing fastness of dyes.

3. Dyeing time

The long dyeing time is conducive to the dye uptake and diffusion of the dye Leucosome. The dark dyeing time should be longer, such as 40 ~ 45min, and the black dyeing time should be longer. When dyeing medium and light colors, the time can be appropriately shorter, such as 20 ~ 30min.