Rieter

Finishing

Index

Just as in yarn processing, certain properties specific to the yarn have to be taken into account when processing fabrics made from rotor-spun yarn. However, the methods do not differ in principle from those used for items made from  ring-spun yarn.

Appropriate finishing processes developed specifically for end products made from rotor-spun yarns, in addition to improvements in spinning technology, have enabled the fabric hand to be decisively influenced. Differences in hand relative to products made from ring-spun yarn, which can still unmistakably be identified in the untreated knitted fabric by specialists, only remain in traces in the finished material.

One aspect must be kept in mind in high-grade finishing of fabrics made from rotor-spun yarn. Some of these processes (e.g. non-iron finish, stone-washed denim) result in reduced fabric strength. Together with the 10 - 15% reduction in raw fabric strength, this can result in values that no longer fulfill make-up or finished product requirements. This reduction must therefore already be taken into account when selecting the raw material and producing the yarn in such a way that yarns are spun with appropriately high strength.

As a result of the restricting influence of the wrapping fibers, napping fabrics made from rotor-spun yarns may call for 1 - 2 napping passages more than comparable fabrics made from ring-spun yarn in order to obtain a comparable napping effect.

Final dyeing results with rotor-spun yarns tend to be darker; in certain cases dyestuff savings can therefore be achieved. However, dyeing brilliancy is generally lower; the fabrics have a duller appearance - due to the yarn structure.

The size take-up of fabrics made from rotor-spun yarns is better than for ring-spun yarns; size concentration can therefore be set up to 15 - 25% lower. This also means that size consumption is lower with the same sizing effect.