Theoretical Analysis on Tensile Properties of Textured Yarns

In this paper, tensile properties of textured yarns will be analysed. First, the property is calculated on the basis of a “independent fiber model” where each fiber contributes independently to the yarn tensile property, i.e., no mechanical interactions among fibers are considered. One of the purpose of this paper is to examine the accuracy of this no-interaction assumption for making distinct the mechanical interaction among fibers. Second, the tensile property of a crimped single fiber is calculated by applying the so-called “strain additive method”.[1] to a helical coil model of a fiber. Then the tensile property of a textured yarn is introduced by summing up the tensile property of each crimped fiber.A good agreement between the calculated and the observed values is obtained over a wide range of the tensile atrain of the yarn by assuming the independent model. No interaction is observed except the small deformation region.The hysteresis behavior observed at the repeated extension is also examined, and it is confirmed that the independent model is still suitable for this case. The experimental results agree well with the calculated results with good accuracy, too.