OPTIMIZING A WOOL DYEING PROCESS WITH AN AZOIC 1 2 METAL-COMPLEX DYE USING COMMERCIALLY AVAILABLE LIPOSOMES/

We investigate the application of a commercially available phosphatidy lcholine liposome suspension of defined size (about 100 nm) as a carri er for the azoic metal complex 1:2 dye Lanaset Yellow 2R to untreated wool fibers at the pilot plant level. To explore the influence of the experimental conditions on the dyeing process and on dyed yarn propert ies, we use a Box and Behnken factorial design for three variables. Fr om this optimization study, we conclude that commercially available li posomes are suitable for dyeing wool at lower temperatures and shorter times than those needed in conventional industrial wool dyeing. Thus, wool may be dyed at 80 degrees C using liposomes at 1-2% owf with sat isfactory dye exhaustion and fixation levels and good mechanical prope rties and handle. The main novelty of this procedure is the use of com mercial liposomes as a simple dyebath additive. Increasing liposome co ncentrations in the dyebath improve dye exhaustion on the fibers at hi gh temperatures, but dye fixation at these temperatures is independent of liposome concentration, depending instead on dye concentration. Li posomes also improve the leveling effect of the dye compared to that w ith conventional auxiliaries in all cases. Although Liposome concentra tion does not significantly affect yarn mechanical properties, there i s an optimal liposome concentration that improves handle (yarn-to-yarn friction).