Effect of elastane draft on the rheological modelling of elastane core spun yarn

The main purpose of modelling the yarn structure is to find relations that are more reliable giving the behaviour of the yarn starting from its components. In this paper, the identification of the mechanical behaviour of the elastic core spun yarns by a rheological modelling on the basis of pre-existent phenomenological models is presented. In this model, the elastic core spun yarn is considered as a viscoelastic material. The model is verified experimentally with two types of elastic core spun yarns 50/78 and 59/156 and a range of draft of five values for two types of yarn and two values of elastane count in dtex (78 and 156). Comparative analysis of the theoretical and experimental tensile curves indicates a high level of correlation between both data-sets. The effect of the elastane draw ratios on the parameters of this model is established in the second part of this paper. Our test results revealed that the elastane draft is one of the important factors influencing the elasticity and the viscosity of elastic core spun yarns.