Peculiar behaviour of the loom's back-rest roller
This paper presents an analysis of the dynamic model of the back-rest roller motion. On modern high-speed looms with growing weaving resistance, the normal beat-up pulse delivered by the conventional reed is not able to produce the desired fabric style. It is necessary to deliver an additional beat-up pulse. In order to determine if the motion of the back-rest roller generates a secondary beat-up, the behaviour of the back-rest roller during weaving is analyzed influencedby loads which are the result of warp tension, weft beat-up and opening the shed. The backward and forward rotation of the back-rest roller are pointed out and the conditions for backing (backward rotating) are determined. It is also shown that the permanent sliding practically eliminates the influence of abrasion of warp by the roller on warp tension. Thus it is impossible to transfer the inertia forces of the back-rest into the secondary beat-up.