Warp tension analysis of narrow fabric weaving and designing of tension compensator to avoid start up marks

Abstract

Start up marks are one of the major defects on woven fabric and this defect occurs when loom restarts after stoppages due to warp tension variation at the time of start. This defect is more prominent in high speed looms and it is critical in manufacturing elastic tapes. In this paper, formation of start-up in elastic tape on a narrow fabric loom was analyzed mathematically and provided a practical technical solution to the problem. In mathematical analysis both continuous operational condition and stopping condition of a narrow fabric loom was taken into consideration and the developed mathematical model established a quantitative relationship between excess warp yarn length fed and the tension variation of warp yarn at the point of starting the loom. A system simulation was carried out using the model developed and compared with the experimental results to show the accuracy of the model. A tension compensating device was proposed to avoid formation of the startup marks. The effectiveness of the proposed solution was proven practically with a prototype developed.