How to improve the wet rubbing fastness of textile fabrics

1. Selection of dyes: the dyes with less floating color and good lifting and leveling properties can improve the wet rubbing fastness to a certain extent. Floating color is the main reason for the disqualification of wet rubbing fastness. The total amount of floating color can be expressed by the difference between the final dye uptake E and the final fixation f in the characteristic value serf, i.e. E-F value. The dyes with low E-F value are easy to remove floating color. Good lifting property and levelness are conducive to dye penetration and diffusion, and improve the wet rubbing fastness of the fabric. The dye should have certain water solubility and directness, and there should not be too many water-soluble groups, otherwise the wet rubbing fastness will be affected. There is a certain relationship between the final dye uptake rate E and the primary dye uptake rate s. e68a84e8a2ade799bee5baa6e997aee7ad9431333332643932 is the best for directness, which should be more than 70% in general. 2. Dyeing and finishing process control: in addition to the correct selection of dyes, a reasonable dyeing and finishing process can also improve the wet rubbing fastness. 2.1 water quality is a very important factor affecting the wet rubbing color fastness of fabrics. If the hardness of water is high, the water-soluble groups of floating dyes will form lake which is difficult to dissolve in water, which seriously affects the removal of floating dyes. Soft water or deionized water should be used as much as possible to reduce the influence of calcium and magnesium plasma in water on dye, so as to improve the absorption of fiber to dye and make dye fixation more stable in fiber molecules. 2.2 the smoother the fabric surface is, the higher the wet rubbing fastness is, so the singeing should be clean and the colored fiber particles should be reduced. The wool effect of dyeing semi-finished products directly affects the dye permeability. The better the dye permeability, the better the dye diffusion to the fiber after dyeing, which is conducive to reducing the accumulation of dye on the fabric surface. The addition of penetrating agent and mercerizing treatment can improve the wet rubbing fastness. 2.3 high efficiency fixing agent should be used. The selected fixing agent should be able to link between the dye and the fiber to form a compound. When it reacts with the dye, it can also react with the cellulose fiber to crosslink, so that the dye and the fiber can be closely and firmly linked, strengthen the combination of the dye and the fiber, prevent the dye from falling off from the fiber or swimming to the surface of the fiber, and avoid the decline of dyeing fastness . 2.4 the auxiliaries used for soaping must have good permeability, be easy to be compatible with dyes, form micelles, reduce the affinity between dyes and fibers, form a core, and make the dye micelles stably disperse in water. It is suggested that the auxiliary agent composed of anionic surfactant and nonionic surfactant with the function of penetration and dispersion should be selected, otherwise, the effect of thoroughly removing floating color can not be achieved. 2.5 pay attention to the pH value of dyed fabric. Generally, the amount of alkali used in deep shade fabric dyeing process is high, and the excessive alkalinity in the fabric is easy to cause the dye hydrolysis, thus reducing the color fastness to wet rubbing. Therefore, the pH value of fabric surface is usually controlled at 6.5 ~ 7.5, not more than 9 or less than 3. 2.6 adequate soaping. The floating color on the fiber is extremely unfavorable to the color fastness to wet rubbing. For the fabric dyed with deep and thick reactive dyes, it is suitable to soaping twice at high temperature. However, it is not easy to soaping too much. Too much soaping will damage the dye already dyed, resulting in bond breaking phenomenon, resulting in the decrease of the effect of rubbing fastness. At the same time, appropriate stripping agent can be added in the soaping process to remove the floating color, so as to improve the color fastness to wet rubbing.