Dyeing wool at low temperatures: New method using liposomes

Dye exhaustion profiles are determined at different times and temperatures in Lanaset dyeing processes in the presence or absence of sodium sulphate u sing a commercial liposome. Ecotrans W-8814, and other low-temperature auxi liaries such as ValSol LTA-N and Baylan NT. The contamination load of the f inal dye baths is evaluated to determine the environmental impact of this n ew low-temperature dyeing process. Ecotrans W-8814 exerts a marked retardan t influence on dye exhaustion at temperatures lower than 70 degreesC, favor ing a uniform final color of the Wool fibers. The presence of sodium sulpha te can be avoided since the liposome vesicles assume the role of retarding agent. The optimal final time and temperature are I hour and 85 degreesC at a liquor ratio of 1:50. However, the same dye exhaustions for the three au xiliaries, 98% (for Lanaset Red G) and 80% (for Lanaset Yellow 2R), are obt ained at 80 degreesC at a 1:25 liquor ratio. Values of the chemical oxygen demand corresponding to the residual dyebaths with the three auxiliaries de monstrate the lower contamination load associated with the liposomes.