The high temperature dyeing assistant disperse dyes on the market are made by dyestuff manufacturers after dispersing non-water-soluble dyes in water evenly. In addition, in the process of dyestuff production, each dyestuff manufacturer produces dyestuff according to their own experience and technology, and the technical conditions are different. Dyestuff production is an area with great differences in technical level. Even disperse dyes with the same color index number have different dispersibility due to different manufacturers, so only dyeing aids can help solve the problem.
According to the proportion of disperse dyes sold on the market, the parent dye contains 25%-60% and the anionic dispersant 75%-40%. When purchasing dyes, users usually only pay attention to the parent and price of dye pigments, so most manufacturers have to use cheap dispersants to reduce costs. Of course, these disperse dyes are poorly dispersed.
The anionic dispersant can exert the most effective dispersing effect in the range of 30 60 C, but the dispersing effect is not good at the high temperature of 110 130 C. Therefore, even if the disperse dyes with excellent dispersibility at room temperature are dyed at high temperature, the phenomenon of dispersity weakening and dye agglomeration is easy to occur. In order to prevent poor dispersion, it is necessary to use additives to help solve the problem.
In summary, when choosing high temperature dyeing auxiliaries, we must first pay attention to whether they can make up for the lack of Dispersity of dyes. The dispersibility of dyes is different, and the dispersing effect of dyeing auxiliaries is different, so the properties of auxiliaries required by different factories are also different.
Recently, less and less dispersible dyes have appeared on the market. But for the sake of safety, polyester-cotton cloth was used to filter disperse dyes to confirm their quality. When there is insoluble residue or small particle residue, even the use of dyeing auxiliaries is ineffective.
When dyeing at high temperature, in addition to the good dispersing agent, the assistant which has defoaming effect or is not easy to pollute the dyeing vat when dyeing at low bath ratio is generally chosen. Additives with good soaking effect should be selected for dyeing heavy or high density fabrics, which are consistent with the dyed fabrics.