Rieter

The comber‘s task

Index

The comber is used in the production of medium, medium-fine and fine  yarns, and enables a positive influence to be exerted primarily on the  yarn characteristics of:

  • evenness;
  • strength;
  • cleanliness;

and on the fabric characteristics of:

  • smoothness;
  • visual appearance; and
  • handle.

It is also employed to improve working behavior in downstream processing, most noticeably in knitting. In addition, yarn made from combed cotton needs less twist than a  carded yarn. However, as we have already mentioned, these quality improvements are obtained at the cost of additional expenditure on machines, floor space and personnel, together with a loss of raw material. Yarn production costs are increased by something less than USD 0.3 per kilogram of yarn (depending upon the intensity of combing).

To achieve an improvement in quality, the comber must perform the following operations:

  • elimination of a precisely pre-determined quantity of short fibers;
  • elimination of the remaining impurities;
  • elimination of a large proportion (not all can be removed) of the neps in the fiber material;
  • formation of a sliver having the optimal possible quality parameters.

Elimination of short fibers produces an improvement mainly in  staple length, but it also affects the fineness of the raw material. Since noil is on average finer than the original raw material, the  Micronaire value of combed sliver is slightly higher than that of the feedstock. It should also be noted that combing increases the parallelization of the fibers, but this is a side-effect which is not always an advantage. The high degree of parallelization might reduce inter-fiber adhesion in the sliver to such an extent that the fibers slide apart, e.g. while being pulled out of the can – i.e., sliver breaks or false drafts might be caused.