Eco-friendly single bath dyeing of wool yarns with extracted cochineal dye: optimization and additives effect

Abstract

Purpose The purpose of this study is simultaneous dyeing and mordanting of wool yarns with extracted cochineal dye and aluminum sulfate to the reduction of consuming energy, water and time. Design/methodology/approach The dyeing process was optimized using the response surface methodology (RSM) approach. pH, dyeing duration and the presence of additives were chosen as variables and the color strength of samples as a response. The color characteristics and fastness attributes of samples dyed in the best condition were evaluated and compared to pre-mordant dyeing outcomes on wool yarns. Findings The best conditions for deep dyeing wool with cochineal dye were as follows: pH 2.5, time 110 min and the ratio of aluminum: additives 1:0 at 100 °C. Color strength of dyed wool yarns by one-bath and pre-mordant dyeing methods were approximately the same. Wool yarns can dye to the on-bath dyeing method such that the dyed samples have similar color strength and fastness properties to pre-mordant dyeing. Social implications Wool dyeing processes that use one-bath dyeing consume less water and produce fewer effluents. As a result, this strategy conserves water and energy for a higher quality of life. The findings of this study, in general, aid environmental protection. Originality/value A novel one-bath process for dyeing wool with cochineal dye at heavy depths is introduced. RSM was used to optimize the procedure and determine effective parameters on the color strength of dyed wools. Using extracted cochineal dye and aluminum sulfate in a simultaneous dyeing technique, good color fastness qualities on wool fibers were achieved.

Valorisation of sulphonated lignin as a dye for the sustainable colouration of wool fabric using sustainable mordanting agents: enhanced colour yield, colourfastness, and functional properties

“…Therefore, textiles dyed with natural dyes undergo post or pre-mordanting treatment with heavy metal salts and tannins to form a dye–metal complex to reduce the water-solubility of the applied natural dyes and also to bind them to fibres enhancing their colourfastness to washing. 31–34 Chromium salts are popular mordanting agents, but they are highly toxic to the environment, and hexavalent chromium is a possible carcinogen. 35,36 In this article, for the first time, we are reporting the improvement of colour yields, shades produced, and colourfastness to washing of wool fabrics dyed with SL using various sustainable mordanting agents in a single step.…”