Investigation into the effect of UV/Ozone treatments on the dyeing properties of natural dyes on natural fabrics

摘要

The effect of uv/ozone treatments for different periods on dyeing properties of three different natural fabrics, i.e. wool, silk, and cotton dyed with two natural dyes have been investigated. The results indicated that, the presence of tyrosine in the molecular structure of protein fibers- wool and silk- are considered the most important source of photo-yellowing, where it is oxidized by uv/ozone treatments into yellow chromophore. The improvement in both dyeability and light fastness of the treated fabrics follow the order: wool > silk > cotton. UV/ozone oxidize cystine linkage present in wool fiber surface to cysteic acid, the surface become more hydrophilic, thus the dyeability improved. Higher light fastness of the treated dyed wool fabrics may be due to the strength of the linkage formed between the reactive species resulted during different treatment times and the dye particles.