In the process of dry heat treatment, the color fastness of polyester fibers dyed with disperse dyes decreases and the color light changes. It is caused by the thermal migration of disperse dyes.
The so-called thermal migration refers to a phenomenon in which part of the dye migrates from the inside of the fiber to the surface of the fiber during the dry heat treatment process above 130°C after dyeing with disperse dyes.
It is generally believed that the thermal migration of disperse dyes is due to the solvents (surfactants, softeners, resins, antifouling agents, antifouling agents that dissolve the disperse dyes and dissolve the disperse dyes) on the fiber and the solvent attached to the fiber surface under dry heat conditions. Electrostatic agent, etc.) the distribution phenomenon in the two phases. It is believed that if there is no second phase solvent on the surface of the fiber, thermal migration will not occur.