Improvement of the process of dying of wool with natural dyes

This article describes the process of dyeing bleached wool fibers with natural dyes using aluminum, iron and copper salts as a mordant (the coloristic features of the cinnabar dyeing process are studied). The staining process was carried out in three different sequences: pre-treatment with mordants, then staining in a natural dye solution (I); one-bath dyeing in a solution of dye and mordant (II); dyeing in a solution of natural dye, followed by treatment with mordants (III). The influence of the staining sequence on the quality of staining was evaluated by data determined under standard illumination D65 on a laboratory colorimeter. The article shows the dependence of the processes of dyeing wool with natural dyes Madder (Rubia tinctorum L.), Turmeric (Cúrcuma lónga) and Carmine (Minium - cinnabar) on the presence and place of pickling salts in the technological wiring. Madder dye itself gives a golden color, and in the presence of copper sulfate and iron gives a pale brown color, and potassium dichromate gives a bright saturated red color. When dyeing wool with Carmine dye in the presence of iron and copper salts as mordants, carmine wool gives 1.5-2.5 times more intense dark red colors, depending on the dyeing method, than when dyed without salts. The dependence of the color intensity on the pH of the medium has been studied, taking into account the fact that the pH of the dyeing process affects the strength and color parameters of the colors obtained on wool fiber with natural dyes. An IR spectral analysis of samples dyed with the studied dyes was carried out in comparison with undyed wool fiber to identify the nature of the occurrence of bonds between wool fiber and natural dyes.