Rieter

General

Index

Two quality criteria are decisive in describing a yarn. The structure, i.e. the arrangement of the fibers in the yarn cross-section and along the yarn, and the physical textile characteristics in terms of the uniformity and strength of the fiber bundle, the number of yarn defects (Table 20), etc. While the external structure is the decisive criterion for final appearance, form, wear behavior, etc., of the final fabric, the physical textile characteristics are decisive for the load-bearing capacity of the yarn during weaving preparation and on the weaving or knitting machine, as well as for the serviceability of woven or knitted fabrics.

Rotor-spun yarns have an unmistakable structure, characterized by the rather indifferent twist insertion in the surface of the yarn compared to ring-spun yarn – twist is imparted preferentially in the yarn core – and the systemrelated wrapper fibers. In contrast to rotor-spun yarn, twist is imparted in the surface of ring-spun yarn, and virtually all fibers are integrated uniformly along the spiral line of the yarn twist. Twist insertion and the creation of wrapper fibers is explained in the two previous sections.

1) Positive or negative, depending on the end product;2) Virtually the same as ring-spun yarn in the end product after finishing (see Table 19); Table 20 – Properties of rotor-spun yarn compared to ring-spun yarn