Rieter

Operating principle

Index

Suessen has offered two machine types: PL 1000, with medium packages for yarn in the linear-density range of 25 - 100 tex, and PL 2000, with large packages for a yarn linear density of 25 - 500 tex. Three-, four-, or five-roller drafting arrangements are used, depending upon the raw material to be processed. The hollow spindle (Fig. 20) permits rotation speeds of up to 35 000 rpm and is designed as a false-twist assembly. The fiber strand (Fa) does not pass directly through the spindle vertically; instead, shortly after entering the spindle, the strand is led out again (1) and back around the spindle, with a wrap of about one-quarter of the spindle periphery. In this way, as the spindle rotates, the strand is provided with twist between the drafting arrangement and the head of the hollow spindle. These turns of twist are canceled out again in the spindle head in accordance with the false-twist principle. This false twist prevents the strand from falling apart in the length prior to wrapping with filament (Fi).
Slivers are used as feedstock; the roving frame is eliminated. ParafiL yarn (called Parallelyarn by Suessen) is usually more even than ring-spun yarn. Its strength is also better because of the filament and because of the high degree of parallel orientation of the fibers. Covering power is high and hairiness low.
The yarns are used primarily for:

  • machine-knitting yarn;
  • velours (home and automobile upholstery materials);
  • woven goods (men‘s and ladies‘ wear);
  • carpet yarns (mainly for tufted carpets).

At present, the process is more suited to the long-staple than the short-staple field, i.e. for fiber lengths above 60 mm. In ParafiL yarns, the filament makes up 2 - 5% of the yarn.

Fig. 20 – The false-twisting device in the ParafiL process by Suessen