Method of uniformly dyeing high temperature heat set polyester yarn

摘要

A method is disclosed of pretreating a plurality of high temperature heat set yarn bundles, e.g. polyester, that have different heat histories but are otherwise identical, to enable said yarns to be dyed uniformly. The method comprises measuring the pre-melt crystallization temperature of each polyester yarn bundle and thereafter heat treating each yarn bundle at a uniform temperature that is at least the same as or higher than the highest measured pre-melt crystallization temperature. Also disclosed are a method of uniformly dyeing polyester yarn bundles that are treated in a plurality of high temperature heat setting units and a method of determining the evenness of the internal temperature of high temperature heat setting apparatus.