What are the measures to improve the light fastness?

1. The choice of dye

The most important factor affecting the light fastness of light-colored fabrics is the dye itself, so the choice of dye is the most important. When selecting dyes for color matching, make sure that the light fastness level of each component dye selected is equivalent, as long as any one of the components, especially the component with the least amount, can not reach the light fastness of the light-colored dyed material. The light fastness of the final dyed product will not reach the standard.

2. Other measures

(1) The influence of floating dyes

Dyeing and soaping is not thorough, and the unfixed dyes and hydrolyzed dyes remaining on the cloth will also affect the light fastness of the dyed products. Their light fastness is significantly lower than that of the fixed reactive dyes. The more thoroughly the soaping is done, the better the light fastness.

(2) The influence of fixing agent and softener

Cationic low-molecular-weight or polyamine-condensed resin type fixing agent and cationic softener are used in fabric finishing, which will reduce the light fastness of dyed products. Therefore, when choosing fixing agents and softeners, attention must be paid to their influence on the light fastness of dyed products.

(3) The influence of ultraviolet absorbers

Ultraviolet absorbers are often used in light-colored dyeings to improve light fastness, but they must be used in a large amount to have some effect, which not only increases the cost, but also causes yellowing and strong damage to the fabric, so it is best not to use this method.