Broken Warp Threads Throughout Weaving
Broken warp threads at the edges aren't usually a problem for me. When they do occur, I understand that the breakage is probably due to draw-in and resulting friction from the reed, so I adjust to prevent breakage by using a temple and allowing enough weft slack. However, when broken threads occur in the middle of the warp, I don't understand the cause. This is particularly annoying because the problem often repeats throughout the weaving. I also notice (though the breakage is not usually in this area) that in the center of the warp there is about an inch of separation between the warp threads because of the way the spring-steel bars are clipped to the shafts. Should I worry about that?
First, check to see whether or not the threads that break are always the same ones or are always in the same area of the warp. Then check to see whether or not there is some rough edge to the heddles in those places or any other irregularity you can detect. Are the breaking threads on the last shaft? It is closest to the back beam and usually rises the highest, therefore putting more strain on the threads it carries than the other shafts do. Also observe where the threads are breaking. Do they break within the castle/shaft area? Do they break at the reed? Between the reed and the fell? Make sure that you have observed everything that might affect some threads differently from others.
If you can’t find any cause and if your selvedge threads are not breaking, somehow the action of being raised and lowered (which does unavoidably provide some friction where the threads rub against the heddles) is weakening the threads so that they either fray apart there or in their weakened state break when the beater hits their weak spots at the fell. The best way to avoid this breakage is to advance the warp often, giving each spot on each thread a minimum number of times to be rubbed by the moving heddle. This problem could be even greater with a warp of relatively fine threads that are somewhat closely sett and you are using inserted-eye heddles. The rubbing of the wide eyes on adjacent threads can cause considerable friction. Again, advance the warp often often often often. Did I say often enough? Often!
Many looms show a separation between warp threads on each shaft where the clips attach the spring steel bars. This shouldn’t be a problem, especially if you advance the warp often, as often as every inch.