Interaction between disperse dyes and non-ionic surfactants during thermo sol dyeing of polyester

t', partial contact mechanism" and partial dissolution mechanism", Some specific agents may be included in the pad-bath to promote dye fixation during thermosoling" - 9. Substances recommended for this purpose are hydroxyethylated fats or fatty alcohols'", polyglycols and their esters!' -!4. The use of non-ionic ethylene oxide condensate of high cloud points has been shown to be beneficial in increasing the colour yield in the dyeing of polyester using dry heat fixation technique! 5 - 17. However, some authors1S-ZI express the view that non-ionic surfactants have adverse influence on stability and colour yield, indicating an increase in the rate of crystallization and aggregation of some disperse dyes. Although several mechanisms+ - 26 have been suggested regarding the function of these agents, there appears to be much uncertainty with regard to how much solid-solution or even molten-solution mechanisms contribute to disperse dye fixation in the thennosol process. The objective of this work is to make a comparative analysis of the mode of fixation