Dyeing of Cotton Fabric with Natural Dyes Improved by Mordants and Plasma Treatment

Nowadays, there is a great tendency for eco-dyeing and finishing of textiles with natural products. several natural dyes have been used for dyeing of protein fibers but a low number have the ability to dye cotton fiber because of low affinity of cellulose to the natural dyes. In this study madder and weld natural colorants were used to dye cotton fabric premordanted with three metallic salts including alum, ferrous sulfate, and copper sulfate. The effects of the concentration of mordant, dyeing temperature, dyeing time and amount of electrolyte on the color strength of dyed samples were investigated. Also, an eco-friendly process, low temperature plasma treatment was employed as a pretreatment to improve the dye exhaustion into the cotton fibers. The fastness properties of cotton samples dyed under different conditions were evaluated and the optimum amount of each variable for obtaining the highest values of color strength and fastness properties in the dyeing of cotton with madder and weld natural dyes was specified.