What is the reason for the decrease in fastness caused by thermal migration after disperse dyeing?

Thermal migration is a redistribution phenomenon of disperse dyes in two-phase solvents. Therefore, all additives that can dissolve disperse dyes can produce thermal migration.

The reason for the thermal migration phenomenon is that the auxiliary agent in the outer layer of the fiber dissolves the dye at high temperature. The dye moves from the inside of the fiber through the high temperature of the fiber capillary to expand and migrate to the surface of the fiber, causing the dye to accumulate on the fiber surface, causing a series of effects , Such as discoloration, staining other fabrics when ironing, resistance to friction, washing, perspiration, dry cleaning and sunlight, the color fastness decreases. Practice has shown that the thermal migration of dyes from the inside of the fiber to the outside of the fiber is directly related to the depth of dyeing. The deeper the dyeing depth of the fiber, the greater the amount of dye thermally migrated from the inside to the outside, and the greater the impact on the dyed product; The thermal migration of disperse dyes has a greater impact, and the higher the temperature, the greater the impact.

Therefore, try to use a gentle process when finishing dyed fabrics. The thermal migration of disperse dyes is related to the molecular structure of the dye itself. The widely used non-ionic surfactants found in production practice are the main reason for the thermal migration of disperse dyes.