The influence of dyeing auxiliary on color fastness in the dyeing process is multifaceted. The following are some of the main influencing points:
The role of dye fixing agent:
Dye fixing agent is an important type of dyeing auxiliary. It fixes the dye firmly on the fiber through specific chemical reactions, such as ionic bonding, film-forming wrapping, covalent cross-linking fixation, etc., thereby improving the color fastness of the fabric.
However, some dye fixing agents may change the structure or conjugated system of the dye after combining with the dye, resulting in changes in color fastness indicators such as light fastness. Especially when dyeing dark colors, this effect may be more obvious, and the decline is generally 0.5 to 1 level.
The influence of surfactants and chelating dispersants:
In the soap bath of post-treatment of reactive dyes, the surfactants or chelating dispersants used may remain on the fabric and react with the reactive dyes on the fabric, or affect the reactive dyes dyed during the soap washing process. These effects may change the adhesion state of the dye, thereby affecting the color fastness.
Effect of softener:
After dyeing, fabrics may need to be softened. Different types of softeners attached to fabrics may react with reactive dyes on fabrics, thereby affecting the light fastness of reactive dyes that have been dyed. But generally speaking, the effect of softeners on color fastness is not as significant as that of fixatives.
Effect of light fastness enhancers:
If the dyeing and fixation processes of the colored fabric have been completed, but the color fastness does not meet the requirements, you can consider using light fastness enhancers or ultraviolet absorbers for repair and rework. This type of auxiliary agent can absorb ultraviolet rays irradiated on the fabric, prevent the dye from being damaged by photooxidation, and thus improve the color fastness. For example, the use of SC light fastness enhancer can generally increase the light fastness of the fabric by 0.5 to 1.5 levels on the original basis.
In summary, the influence of Dyeing Auxiliary on color fastness during the dyeing process is multifaceted, with both positive promotion and potential adverse effects. Therefore, it is necessary to reasonably select and use Dyeing Auxiliary during the dyeing process to optimize the dyeing process and improve the color fastness of the fabric.
