Dynamic Behavior Analysis of Yarns During Knitting Process of Fabrics

Knit products are widely used in our daily lives because of their excellent elasticity and flexibility. Most of such products are usually composed of flat knitted fabric, which is the basic structure of knitted fabric. This unique structure of it gives knit products high functionality. However, since flat knitted fabric is easily affected by material properties of yarn and knitting machine, and defects that cause the loops of knitted fabric to tilt often occur. Especially, a defect in which the loops of the knitted fabric tilt alternately to the left and right at each step is called Yotari. Since the functionality of knit products are impaired by this defect, the cause of Yotari is needed to be investigated. In this paper, two hypotheses of Yotari are proposed, and the purpose of this paper is to test one of them. For this purpose, firstly, a yarn is modeled because it makes up knitted fabric. Secondly, the knitting process is modeled because influence of knitting process should be considered. Finally, the proposed simulation models are used to analyze the dynamic behavior of yarns knitted in a knitting machine. Then, the results of this simulation are used to test the hypothesis of Yotari.