Ultrasound Assisted Dyeing of Cellulose Acetate

The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with disperse dyes using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or joining the mechanical and ultrasound agitation in the bath where the temperature range was between 60°C and 80°C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries. Hence the corresponding half dyeing time, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on dyeing kinetics. Finally, the fastness test gives good values for samples dyed with ultrasound technique even without use of auxiliaries. Those results suggest the possibility to work up a well equalized dyeing of cellulose acetate without using additional chemicals into the dye bath.