Yarn tension forces in the loop creation process in flat weft machines

Abstract

In this paper, presented are the investigation results of yarn tensioning dynamics, i.e. the yarn tension as time dependent in flat weft knitting machines. The investigation results have shown that the yarn tension forces have an oscillatory character in the loop creation process, which is a function of the wefting depth, the type and fineness of the yarn used, as well as individual phases of the loop creation process. The maximum values of yarn tension, as well as the maximum oscillations, occur in the laying and wefting stages of the loop creation cycle. That means that the probability of unwanted yarn deformation and breakage is the greatest within these stages. In flat weft knitting machines, the input tension of the yarn can be used for the analysis of the loop creation process, i.e., as a means of control of the knitting process in order to achieve the adequate adjustment of technological parameters, to analyze the error conditions, and to insure high quality knitting process.