Rieter

Anti-patterning device

Index

Normally, the yarn windings are distributed irregularly over the whole surface of the package. However, it can happen that the turns of a new layer are deposited exactly on top of the turns of the preceding layer, and this process repeats itself for several successive layers (turn on turn on turn, etc.). This generates uniformly intersecting (rhomboidal) ridges, so-called pattern windings or pattern zones. They reduce the take-up capacity of the package and make unwinding difficult, and are therefore to be avoided at all costs. Their occurrence is determined by mathematical relationships between the traverse frequency and rate of revolution of the package, mainly by ratios of 1:1, 1:2, 1:3, etc. An anti-patterning device minimizes pattern winding (frequent parallel layers) on the package. Pattern windings emerge at certain package diameters depending on stroke and winding helix (see Table 1). The antipatterning device continuously varies the motion speed of the traverse gear. Thus, the winding helix is changed continuously, preventing the build-up of patterns to a large extent.