Comparison of aluminum mordants on colorfastness of natural dyes on cotton and bamboo fabrics

Abstract

The recent green movement has created strong interest in sustainable practices in the apparel and textile industry. Accordingly, natural dye usage has increased in popularity over the recent years, as well as alternative fiber sources such as bamboo. Because of the inherently poorer fastness properties of natural dyes compared to synthetic dyes, additional research on natural dyes and mordant agents is necessary to obtain the best colorfastness results. Many salts, called mordants, are used to help affix natural dyes to fabrics, called mordants, but the most common is potassium aluminum sulfate. However, it has been suggested that aluminum acetate can be a substitute, if not a better mordant than potassium aluminum sulfate for cellulose fibers. This study compared the colorfastness of these two mordants in three different amounts including 5%, 10%, and 20% per weight of fiber (WOF). Three natural dye extracts (madder, weld, and coreopsis), were used to dye seven test fabrics, including a bamboo rayon jersey, two bamboo rayon woven fabrics, a cotton interlock knit, two woven cottons, and a bamboo rayon and cotton blend interlock knit. Lightfastness and colorfastness to laundering tests were conducted, and Gray Scale ratings were analyzed using ANOVA statistical analysis. This analysis showed significant four-way interaction between all variables. Results supported aluminum acetate as a more colorfast mordant for cellulose fibers. This research was supported in part by Agricultural Research Experiment Station at the Kansas State University.