Ultrasonic Effects on the Kinetics and Thermodynamics of Dyeing Wool Fiber with Reactive Dye

Abstract

Decreasing the temperature for dyeing wool fiber with reactive dye using a laboratory based ultrasonic machine was investigated as a way to obtain good quality dyed samples. Ultrasonic irradiation was used to reduce dyeing time and temperature whilst increasing dye migration and fastness. The ultrasonic machine was set at a 40 kHz frequency level, with effective power of 130 W and heating power of 350 W to carry out the dyeing process of the wool fiber within the temperature range 60-80 °C. The dyeing processes used both ultrasonic dyeing and without ultrasonic dyeing to obtain the laboratory results. At every dyeing stage from 60 °C to 80 °C, the exhaustion rate of dyeing was measured. Ultrasonic dyeing yielded better results compared to without ultrasonic dyeing. The diffusion coefficient, partition ratio, and standard affinity increased with the increased dyeing temperature and the use of an ultrasonic bath. The efficiency of ultrasonic dyeing was measured and the absorption rate constant was at least 55 % greater than without ultrasonic dyeing at every dyeing temperature i.e. 60 °C, 70 °C, and 80 °C. The color fastness to washing and rubbing was better for samples dyed with ultrasonic dyeing. Scanning electron microscopy (SEM) was used to measure the surface changes of the fiber. SEM analysis showed no evidence of scale damage on the wool fiber surface.