Thick and Thin Places in Fabrics during Weaving

Abstract

The purpose of this article is to clarify the relation between the causes for setting-on areas in fabrics and their scales. We have made several experiments to grasp the tendency of scales and analyzed them by using the equations on warp tension which were established in Part 1 and the equation on bending of the race which was introduced in this report.In the light of the results, we have tried to make clear the causes for setting-on areas and find the means to avoid them. We have reached the following conclusions:(1) To make setting-on areas small in scale, the moment of inertia of the tension roller system must be made as small as possible for the automatic bobbin changing cotton loom and the spring constant of the tension spring must be made as small as possible for the water jet loom.(2) The change of the loom speed when the loom starts or stops has great influence on the scales of setting-on areas.(3) On the automatic bobbin changing cotton loom, the scale of setting-on areas in fabrics is affected mainly by the change of the warp tension. On the water jet loom, it is affected mainly by the bending of the race.(4) To avoid setting-on areas due to fluctuations in the beating-up tension of warp just before or after the loom starts, we should do well to equalize this tension to the tension in its stationary running state. That is, compensate for the warp tension around the beat-up point so as to satisfy the following equation: where ∫ba; f(t)dt=∫ba; g(t)dt f(t): Warp tension curve in stationary running state. g(t): Warp tension curve in starting or stopping state. a, b: Beginning and end of beating-up.