Good and poor color fastness directly affects the quality of textiles, as well as the health and safety of the human body. In the process of wearing products with poor color fastness, rain and sweat will cause the pigments on the fabric to fall off and fade. The dye molecules and heavy metal ions may be absorbed by the human body through the skin and endanger the health of the human skin. On the one hand, it will also affect other clothing worn on the body to be stained, or stain other clothing when washed with other clothing.
Today, the editor will take everyone to discuss the solution to sublimation fastness.
It refers to the migration and vaporization of dye molecules inside the fabric when the dye molecules inside the fabric encounter heat 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, textiles and clothing require sublimation fastness above 3-4.
How to improve sublimation fastness:
1. Use high-temperature, macromolecular (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 aids.
Among them, 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 sulfide method. This method has a good fixing effect, but the amount of waste water is large, time-consuming, and there are potential safety hazards. It is also possible to use a new type of environmentally friendly fixing agent, which has the same fixing effect as the traditional caustic soda+sodium sulfide method, with less waste water, time saving, and no safety hazards. It is of great significance to energy saving and consumption reduction production.