Study of the mechanical behaviour of the elastic-core-spun yarns

The elastane-core-spun yarns are hard to be controlled because of the absence of specific tests. Therefore, this study is aims to determine the appropriate conditions to test the mechanical behaviour in term of tensile and relaxation tests. In the present study, cotton-covered elastane-core-spun yarns were used with the same twist factor and various elastane draft values. The analytical results showed that the pretension necessary to deploy the elastic-core-spun yarn increases while the elastane draft increases. Moreover, the elastane ratios have an important effect on the yarn properties for different tests, especially the tensile and the relaxation tests. Besides, the experimental conditions such as the extension rate and the specimen length have a great influence on the mechanical properties.