Dyeing Wool at Low Temperatures: New Method Using Liposomes

Abstract

Dye exhaustion profiles are determined at different times and temperatures in Lanaset dyeing processes in the presence or absence of sodium sulphate using a commercial liposome. Ecotrans W-8814, and other low-temperature auxiliaries such as Valsol LTA-N and Baylan NT. The contamination load of the final dye baths is evaluated to determine the environmental impact of this new low-temperature dyeing process. Ecotrans W-8814 exerts a marked retardant influence on dye exhaustion at temperatures lower than 70°C, favoring a uniform final color of the wool fibers. The presence of sodium sulphate can be avoided since the liposome vesicles assume the role of retarding agent. The optimal final time and temperature are 1 hour and 85°C at a liquor ratio of 1:50. However, the same dye exhaustions for the three auxiliaries, 98% (for Lanaset Red G) and 80% (for Lanaset Yellow 2R), are obtained at 80°C at a 1:25 liquor ratio. Values of the chemical oxygen demand corresponding to the residual dyebaths with the three auxiliaries demonstrate the lower contamination load associated with the liposomes.