Sublimation fastness: refers to the migration and vaporization of dye molecules inside the fabric when heated during high-temperature processing or storage of colored fabrics. Dye molecules will migrate from the fabric to the surface of the fabric when heated, which will reduce the color fastness of the fabric and seriously affect the quality of the textile. The sublimation fastness is evaluated by the gray graded sample card for the degree of discoloration, fading and staining of the white cloth after the dry hot pressing treatment. There are 5 grades, 1 is the worst, and 5 is the best. Generally, the sublimation fastness of textiles and clothing is required to be above 3-4.
1. Use high-temperature, macro molecular (above 350) disperse dyes;
2. Auxiliary selection, use good fixing agent and fastness enhancer;
3. The choice of process flow is one-time shaping or high-temperature shaping first and then low-temperature rolling additives.
The selection of additives can be divided into two parts, the fixing agent after dyeing, and the fastness enhancer during high temperature setting. The fixing agent can use the conventional caustic soda + sodium hydroxide method, which has a good fixing effect, but the amount of waste water is large, time-consuming, and there are hidden safety hazards.