Dispersion behavior of CI Disperse Yellow 54 in high temperature dyeing

The dispersion behavior of C.I. Disperse Yellow 54 under dyeing conditions is assessed by the turbidity ratio, which increases with decreasing dye particle size. Two different dye dispersions are prepared by milling presscakes for 1 and 25 hours. The sizes of small dye particles are mon likely to increase than larger ones during dyeing at elevated temperatures; this enlargement is attributed to crystalline growth. Dyes excluded from adsorption on polyester fibers are enlarged during the dyeing process. At first, dyes of small particle size show lower exhaustion values than larger ones, but eventually they show higher values at temperatures above 130 degreesC.