Rieter

Classification

Index

The operations to be carried out in this spinning process are the same as those required for rotor spinning:
  • opening of the fiber strand;
  • acceleration of the fibers;
  • collecting the fibers into a new strand;
  • imparting strength by twisting;
  • withdrawal of the resulting yarn;
  • winding onto a cross-wound package.

Opening is performed by the elements already used for this purpose in rotor spinning. Collection of fibers can be performed on moving or stationary surfaces, and twisting can be effected by a transfer of forces from some kind of surface. Several different kinds of collection procedure and many different types of surface can be used. Accordingly, there is not just one kind of friction-spinning system, but there are several. They can be distinguished according to:

  • feed:
    (a) single-sliver feed;
    (b) multiple-sliver feed (Dref-2000 and Dref-3000);
  • opening assembly:
    (a) one opening assembly;
    (b) two opening assemblies or drafting devices (Dref-3000);
  • separation of collecting and twisting functions:
    (a) collection and friction assemblies separated;
    (b) friction assembly also serves as collecting device;
  • number of friction surfaces:
    (a) one friction surface (Dref-1);
    (b) two friction surfaces;
  • type of friction assembly:
    (a) perforated drums;
    (b) one perforated drum with one smooth drum (blind drum);
    (c) two discs;
    (d) disc and roller in combination;
    (e) two crossed belts.
The most widely used types are those with the following characteristics:
  • single-sliver feed;
  • one opening roller;
  • friction assembly also acting as collection device;
  • two friction surfaces;
  • two perforated drums or one perforated drum and one blind drum in combination.