Methods for identifying the quality of disperse dyes

From the perspective of dye application, the quality of disperse dyes mainly depends on five aspects: diffusion, dispersion, high-temperature dispersion stability, tar content and thermal mobility. There are 1 ~ 2 Fuzzy infiltration rings at the dropping place of some dye solutions, with a small area. There is an aqueous solution outside the infiltration ring of dye solution. This kind of dye should be added with 20% ~ 30% diffusion agent MF when stirring, or 2G / L disperse dye repair agent to improve the diffusion of dye and the migration of dye.

Diffusivity test: accurately weigh 1g of dye, add 100ml of 30 ℃ water, stir it evenly with a glass rod, drop 4-5 drops of dye suspension on the filter paper with a straw, and observe its natural infiltration circle. If the diffusivity is good, the larger its area is. There are 1 ~ 2 layers of fuzzy infiltration circle at the dripping place of some dye solutions, with a small area. There are aqueous disperse dyes outside the infiltration circle of dye solutions. There are several methods to identify disperse dyes

Pay attention to prevent dye migration during pre baking and baking. The hot melt baking stage is an important stage for the transfer of disperse dyes on cotton to polyester. The appropriate hot melt temperature and time should be selected according to the heat resistance of the dye, that is, the sublimation fastness of the dye. In the actual dyeing, the dye transfer cannot be complete. There is always some dye left on the cotton, resulting in the staining of the cotton. The post dyeing treatment can be carried out by reducing cleaning or soaping. If the cotton part needs to be dyed after the hot-melt dyeing, the post-treatment can be selected after the dyeing.

High temperature and high pressure dyeing of disperse dyes can be carried out on high temperature and high pressure jigger, jet and overflow dyeing machine. It is suitable for dyeing deep and thick color. The dyeing pH value is generally controlled at 5 ~ 6. Acetic acid and ammonium dihydrogen phosphate are commonly used to adjust the pH value. In order to keep the dyeing bath stable, dispersant and high-temperature leveling agent need to be added during dyeing.