Method and apparatus for imparting false twist to yarn before ring spinning

Abstract

The invention discloses a method and apparatus for imparting false twist to a yarn before ring spinning, and a ring spinning machine comprising the apparatus. Downstream of a nip, the twisted yarn is drawn sequentially across first and second runs of travelling endless belts, such that the yarn wraps about a first convex surface of the first run, then passes between the first and second runs, before wrapping about a second convex surface of the second run. Friction between each of the first and second convex surfaces and the yarn imparts the false twist in a common direction. Maintaining a differential between first and second linear speeds of the first and second runs, respectively, has been found to reduce yarn defects, particularly the nep count. 本发明公开了一种在环锭纺纱之前对纱线施加假捻的方法及装置，以及包括该装置的一种环锭纺纱机。在辊隙的下游，牵拉加捻的纱线使其依次跨过行进环形皮带的第一和第二运行部，这样纱线包绕第一运行部的第一凸表面，然后在包绕第二运行部的第二凸表面之前在第一和第二运行部之间通过。第一和第二凸表面的每一个和纱线之间的摩擦在共同方向上施加假捻。已经发现在第一和第二运行部的第一和第二线速度之间相应地保持差异可以减少纱疵，尤其是结节数量。