Theoretical Prediction on Tensile Model of Wool/Spandex Core-spun Yarn

With the innovation of spinning method and Lycra ® fiber, wool elastic core-spun yarn is applied for more industrial end-uses, which make it meaningful to study the mechanical property of wool/spandex core-spun yarn. Tensile property of staple yarns has been studied by many researchers. However, no research is reported on the tensile property of elastic core-spun yarn. In this paper, a new approach is introduced to calculate and predict tensile property of a wool/ spandex core-spun yarn. The theoretical model introduces a fiber utilization coefficient β to specify the slippage length of fiber. The force on a single fiber is first worked out and then these fiber forces are combined to obtain forces acting on each element. Yarn stress—strain curve is obtained on the basis of wool fiber tensile curve and yarn cross-section structure. Factors, such as dimensions and properties of fiber and yarn, fiber slippage effect, and fiber orientations in the yarn are included in the model. Comparisons of experimental and theoretical tensile curves show that the theoretical model has very good agreement with experimental curves. So this method is valid in predicting the tensile behavior of the wool/spandex core-spun yarn.