Problem and solution of dyeing elastic spandex textiles
¡ª¡ªQian Hongfei, professor of Shaoxing University

Ms. Qian firstly introduced problems in dyeing nylon/spandex and polyester/spandex fibers, especially about spandex. The problems are mainly in color fastness which sees large diveregnce before and after heat setting. In follow-up processes, color points are easy to emerge, which affects product quality. 

Then Ms. Qian shared her studies. There are hard and soft segments in spandex fiber structure. Currently, only soft segment can be dyed but the dyeing is not stable. When spandex/polyester fabrics are dyed, dyestuff absorbs on the surface of spandex but will turn to polyester when surface temporature reaches 110℃. When spandex/nylon fabrics are dyed, dyestuff is steady when temporarture reaches 110℃, but dyestuff on nylon is limited. 

At last, Ms. Qian shared experiences in improvement of dyeing property. Firstly, to filter dyestuff, prior to the specifications with small absorption to spandex. Secondly, to design new disperse dyestuff to improve affinity of spandex component.