Low-bagging (growth) stretch denim yarn production by spinning optimization of cotton-wrapped dual-core elastane and T400 multifilament

Cotton-wrapped elastane core yarns have been widely used in producing stretch denim fabrics due to their comfortable stretching and recovery, but they suffer from undesirable fabric growth under prolonged or repeated stress. To reduce that problem, an additional semi-elastic multifil-ament has been incorporated with the elastane core, called dual-core yarn. Herein, it was intended to produce well-engineered dual-core yarns possessing high elasticity with low bagging. Twenty types of cotton-wrapped elastane/T400 multifilament dual-core yarns with different combinations of elastane and T400 tension draft were produced on industrial scale in a spinning mill. Structural parameters, tensile properties and elastic recovery behavior under cyclic loading of the yarns were thoroughly studied. For an optimum combination of elastane/T400 draft, the dual-core yarn attained excellent tenacity and elongation with significantly low evenness, im-perfections and hairiness values. More importantly, the results of the cyclic loading study explicitly revealed a remarkable reduction in plastic deformation and stress decay indicating low growth and high resilience of yarn after deformation. The dual-core yarn containing high strength, high elongation and low growth obtained here can have durable stretch jeans with high body movement comfort and long-lasting shape retention.

Automated summary

Cotton-wrapped elastane core yarns are commonly used in stretch denim fabrics production but suffer from fabric growth. To solve this problem, a dual-core yarn consisting of elastane and T400 multifilament was developed. The dual-core yarn showed excellent tenacity, elongation, and resilience, with reduced evenness, imperfections, and hairiness values. It can be used to produce durable stretch jeans with high comfort and shape retention.