Comparative study on the thermal shrinkage behaviour of polyester yarn and its plain knitted fabrics

Abstract

Heat-based processes on thermoplastic fibre materials cause the materials to shrink. Knitted fabrics may change their dimensions due to thermal shrinkage of the constituent yarns in the fabric and the change in loop shape. The extent to which the thermal shrinkage of polyester yarn affects the thermal shrinkage of the knitted fabric and the effect of heat on fabric parameters are the focus of this article. The thermal shrinkage behaviour of polyester yarn and the plain knitted fabric made of the same yarns were analysed after subjecting them to dyeing, heat-setting and subsequent heat curing processes. The thermal effects on yarns, the yarns in the fabrics and on the wale and course densities were investigated. Thermal shrinkage in the course direction is highly related to the width-wise extension applied during heat setting and the thermal shrinkage in the wale direction is highly correlated to the shrinkage behaviour of the yarns in hank form.