Optimising by response surface methodology the dyeing of polyester with a liposome-encapsulated disperse dye

Optimisation of conditions for dyeing polyester with liposome-encapsulated CI Disperse Red 50 was performed using response surface methodology. The effects of temperature, time, and lecithin:dye ratio on the colour strength of dyed fabrics were investigated by a central composite design. The coefficient of determination, the probability value in analysis of variance, and the normality plot of residuals demonstrated sufficient significance of the proposed fitness function. It was found that the temperature and time of the dyeing cycle were effective factors in the dyeing of polyester fabrics with encapsulated dye. It was also established that the colour yield of dyed fabrics was above 25 in the case of a dyeing time of >80min, a lecithin:dye ratio of <= 2, and a temperature of ca. 128 degrees C. Comparison of colour strengths produced by liposome-encapsulated dye and commercial dye revealed that there was approximately the same build-up on polyester. Dyeings from encapsulated CI Disperse Red 50 exhibited very similar fastness to dyeings from conventional CI Disperse Red 50.