The role of each process of conventional finishing and its influence on the color of the cloth

Finishing is the last process of the dyeing and finishing process. It is mainly responsible for finishing natural cotton fabrics into finished fabrics that meet the needs of various customers, and providing qualified workwear fabrics for workwear factories. For yarn-dyed fabrics, the production process includes: singeing, desizing, silk finishing, washing, setting, coloring, raising, sanding, rolling, resin, PU coating, and pre-shrinking.

1. Singeing: It is mainly to burn off the fluff on the surface of the cloth to make the cloth surface clean. It has little effect on the color of the cloth.

2. Desizing: remove the sizing on natural cotton cloth by the action of enzymes and high temperature washing. It has little effect on the color of the cloth surface, but it should be noted that some white cloths will be affected by the color of the whitening agent when desizing at high temperature.

3. Silk finish: Silk finish uses the effect of concentrated alkali on cotton fibers to increase the finish and strength of cotton. Usually, the color of the cloth surface will be darker, and with the increase of the alkali concentration after the silk finish, the degree of the darker color of the cloth surface will also increase.

4. Washing: For fabrics containing BLUE R dyes, the washing fastness of the dye is reduced by the action of alkali after the silk is finished. In order to ensure the washing fastness of the finished product, the post-finishing needs to be washed after the silk is finished. It can be seen that the fabric containing BLUE R dye will be lighter and less blue after washing.

5. Soft setting: Due to the self-crosslinking properties of some softeners, they form a film on the surface of the fabric during setting, so they have a certain deepening effect, but the difference is not obvious. In addition, if the sublimation fastness of disperse dyes is not good at high temperature, it may affect the color finish and fastness due to the migration of dyes to the surface layer.

6. Addition color: For the solid color or similar solid color cloth whose surface color is quite different from the standard, the color can be adjusted by jigging.

7. Pre-shrinking: Pre-shrinking is a method of shrinking the fabric to meet customer requirements through mechanical action, and has little effect on the color.