Rieter

The winding process

Index

Cop buildup as described here can only occur if the winding point on the tube is shifted continuously. There are two methods of achieving this.

In addition to the constant up-and-down motion of the ring frame:
  • the ring frame must be continuously raised or
  • the spindle bearing plate must be continuously lowered.

The latter principle has been applied for decades by Rieter for the switching traverse, but is no longer used on new machines. New machines operate nowadays exclusively with a moving ring rail. This now has to perform two movements:

  • continuous rising and lowering in order to apply alternate main and cross windings (layering traverse) and
  • a continuous ascent in very small amounts after each layering traverse in order to fill the cop (switching traverse).

Both movements have an adverse influence on spinning conditions. In particular, the size of the balloon and the winding diameter on the cop are never the same. This results in wide differences in tension during winding. In order at least to reduce the effects somewhat, the balloon checking rings (b) and yarn guide eyelets (c) perform movements similar to those of ring rail (a), albeit by smaller amounts in both layering and switching traverse. For layer winding the ring rail is usually moved slowly but at increasing pace upward, and rapidly but at decreasing pace downward. This results in a yarn length ratio of about 2:1 between the main winding (upward) and the cross winding (downward), whereby the total length of each double layer should be no more than 5 m (better 4 m) for unwinding purposes. The layering traverse of the ring rail is ideal if it is some 15-18% larger than the ring diameter.

Fig. 46 – Motion diagram for the working elements: ring (a), balloon checking rings (b) and yarn guide eyelets (c)