Various outer circumferences in one set of beam.
On the modern warping machine most of them equipped with yarn tension compensating roller or roller aggregate drive with AC motor. The function of this roller is to iron out various yarns tension on warp sheet ,the speed of the roller drive by AC motor synchronize with the speed of the motor which drive a beam to wound a yarn sheet on it. The speed of the roller should synchronize and slower + - 3% against speed of over-run roller on the machine head to get same length ,warped with same number of revolutions, the same outer circumference and the most importance is the individual ends of the yarn must be under the same required tension.
On the warping machine equipped with Numeric computer controller (NC) has facility to make a copy or duplicate for each beam in one set, for example for produce a fabric on tricot machine with 130” on the width, for one bar that will be need 6 warp beam with width 21”.With NC warping can be produce 6 warp beams with a same winding, a same length of the yarn and same outer circumference without any difficultly from beginning of beaming process until the end of beaming process.
However the problem with various outer circumferences also can be happen on machine equipped with NC control if the system of roller aggregate was malfunctions.
Next posting will explain how WA roller is work.