Influence of Anionic Dye Sorption Properties on the Color of Wool Top

Abstract

When wool dyeing with anionic dyes, "right-first-time" production and "batch-to-batch" color reproduction depend on the physicochemical properties of the wool fibers, the sorption properties of the dyes, and numerous technological parameters in the dyeing process. In this research, the effects of two process parameters (pH of dyebath and liquor-to-wool ratio) on dye sorption are investigated during batch dyeing of wool top and, consequently, with regard to color. Dyeing involves four anionic dyes—one acid dye (yellow) and three 1:2 metal-complex dyes (yellow, red, and blue). Dye sorption from unicomponent and bicomponent dyebaths is determined using on-line absorbance measurements, and the color of the dyed samples is evaluated colorimetrically using the CIELAB color system. The results indicate significant differences in the sorptions of the dyes with variations in dyebath pH and liquor ratio, which lead to color differences in wool production.