Abstract
In the weaving process the variations of the warp yarn tension cause irregularities of the weft density of the woven fabrics. Due to the fact that warp yarn tension varies in a great extent depending on the ratios of the take-up and the let-off speed, it is necessary to regulate the speed of let-off in relation to that of take-up operation for keeping warp yarn tension in a certain range allowable for the fabric quality. Therefore it is indispensable to analyze the dynamic characteristics of the take-up and let-off system for obtaining the weaving process optimally. In this research it was tried to get the dynamic characteristics of the let-off/take-up process theoretically, and the behavior of the warp yarn tension was simulated on the basis of the mathematical model, depending on the let-off and take-up speed, tensile properties and feeding tension of the warp yarns. From this research the following results could be obtained: 1) dynamic warp yarn tension can be described by a differential equation, however, nonlinearly with respect to the take-up speed, 2) the behavior of warp yarn tension has a characteristics of a 1st order system in the case of a constant take-up speed, and 3) variations of warp yarn tension can always occur when take-up speed changes.
