Investigating cotton dyeing using exotic wood waste sawdust

Investigating cotton dyeing using exotic wood sawdust. The study investigated the possibility of using extracts from various species of exotic wood, obtained from waste sawdust, for dyeing cotton fabrics. Material from Obeche, Iroko, Merbau, Apple tree, American walnut, Tulip tree, Cumaru and Rosewood were used for the tests. Solutions of oxalic acid, tin chloride, aluminum sulfate and ferric chloride were used as mordants, along with no-mordant tests. The color was determined in the CIE L*a*b* coordinate system. Color fastness was tested using n-hexane for dry cleaning and acidic, alkaline and hydrogen peroxide bleach solutions. The results showed a strong dependence on the type of wood, the mortar used and the washing agent and covered a wide spectrum of color intensity and fastness. The best results were obtained for Rosewood, Merbau and Apple trees, while Tulip tree and American walnut turned out to be practically useless. Among the mordants used, the most intense colors were produced by metal salts, including ferric chloride, which strongly darkened fabrics. Dry cleaning proved to be the mildest of those tested, with the least effect on color fading.