Abstract:

During the formation of lockstitches in the sewing machine, the thread inserted into the stitch link by the needle undergoes extreme destruction as the result of the machine tool’s action. The stage of inserting the interlacement into the needle channel (known as stitch tightening), connected with the thread take-up working programme, is presumed to be the most destructive stage for the thread. In this paper, the model of the stitch tightening process in dynamic conditions is presented. It allows us to assess the location of the interlacement in the stitch link, as a function of the sewing process technological parameters, such as the machine rotary speed, the restraint forces of the needle thread and the bobbin hook thread, the geometrical characteristics of the stitch formation zone, the thread elastic features etc.