What are main factors affecting the thermal migration of disperse dyes?（2）

(5) The relationship between surfactants and thermal migration

Most of the surfactants on polyester fibers have a serious impact on the thermal migration of disperse dyes, and different types of surfactants have different effects on the thermal migration of dyes. The order of commonly used surfactants on the thermal migration of dyes is as follows: diffusing agent NNO <detergent LS <wetting agent JFC <soaping <Remibon A <detergent 209 <high temperature leveling agent 10 <flat plus O. The degree of influence of the same surfactant on the thermal migration of the dye is closely related to its adhesion amount on the fiber, that is, the more the amount of surfactant adhesion on the fiber, the greater the effect.

(6) The relationship between finishing agent and thermal migration (resin finishing, soft finishing, etc.)

In the process of high-temperature finishing of the fabric with resin, if the baking time is prolonged, the amount of dye falling off the fabric will gradually increase, the amount of dye dissolved in the resin layer from the fiber will increase, and the amount of dye migrating to the surface of the resin layer will also increase. The corresponding increase will have a greater impact on the shade.

Commonly used softeners or other finishing agents also have an impact on the thermal migration of disperse dyes, which varies with different varieties. For example, cross-linked silicone softeners have little effect, while surfactants have a serious effect on silicone softeners. The degree of influence of various softeners on dye thermal migration also depends on the processing temperature; as the finishing temperature increases , Its influence is getting bigger and bigger.

(7) The relationship between dyeing method and thermal migration

Experiments show that polyester fabric dyed with disperse dyes, when heat treated at high temperature (above 130°C), part of the dye molecules migrate to the inside, and part of the dye molecules move from the inside of the fiber to the surface of the fiber or into the second phase solvent on the surface of the fiber; However, different dyeing methods have different directions of dye thermal migration. Because atmospheric pressure dyeing is light-colored ring dyeing, after high temperature dry heat treatment, there is almost no sign of thermal migration from the inside to the outside. The dye on the fiber surface has a concentration gradient and moves to the inside of the fiber. Migration or diffusion.

Hot melt dyeing dyes are distributed inside the fiber, and there is also a certain concentration gradient; while high temperature and high pressure dyeing has good penetrability, there is almost no gradient in the distribution of dyes inside the fiber, so during high temperature dry heat treatment, the dye only moves outwards in one direction , Has a greater impact on the color and fastness of dyed fabrics, especially deep to extra dark.

(8) The relationship between heat setting and thermal migration

The dyes dyed by the fixed and unshaped blanks have the same phenomenon of thermal migration of dyes during high-temperature dry heat treatment; the setting before dyeing has a certain inhibitory effect on the thermal migration of the dyed products in the dry heat treatment, but this inhibitory effect is related to It is directly related to the lighter color of the shaped blank from 10% to 15% (the lighter the color, the less the thermal migration of the dye). Therefore, polyester fabrics have a practical impact on the thermal migration of disperse dyes.