Rieter

Influences on the draft

Index

In all types of drafting arrangement, the factors that affect the draft are:

Factors dependent upon the fiber material:
  • mass of fiber in the strand cross section;
  • degree of order of the fibers (parallel disposition);
  • shape of the cross section of the fiber strand;
  • compactness of the fiber strand;
  • adhesion between the fibers dependent upon
    • surface structure,
    • crimp,
    • spin finish,
    • compression of the strand;
  • fiber length;
  • evenness of distribution of fiber lengths (staple form);
  • existing twist in the fiber strand.

Factors dependent upon the drafting arrangement:

 
  • diameter of the rollers;
  • hardness of the top rollers;
  • pressure exerted by the top rollers;
  • surface characteristics of the top rollers;
  • fluting of the bottom rollers;
  • type and form of fiber guiding devices, such as pressure rods, pin bars, aprons, condenser etc.;
  • clamping distances (roller settings);
  • level of draft;
  • distribution of draft between the various drafting zones.