Fibers made of polyester (PES) are of increasing importance. The advantages are a higher fiber strength that enables yarns from PES to achieve the same strength as viscose (CV) yarns, but with a lower twist. Less twisting means higher delivery speeds without increasing rotor speeds. Thus it leads to a more energy efficient production.

In comparison to 100 per cent viscose and 100 per cent cotton, PES blends can save on raw material costs. The fabric is soft and feels similar to 100 per cent  viscose. End products from PES blends are characterised by good abrasion performance, easy care and good wrinkle resistance. The same blends are also used on ring and air-jet spinning machines.

When spinning PES-CV blends, Rieter’s R 60 automatic rotor spinning machine offers particular and special benefits. The better spinning stability of the S 60 spin box allows spinning on the R 60 with a lower yarn twist. Consequently, the delivery speed increases based on the lower yarn twist, but without increasing the rotor speed. This leads to productivity gains. At the same time, energy consumption per kg of yarn is decreasing. The cool-nozzle technology of the S 60 spin box creates a lower surface temperature of the nozzle of around 10 ° C, thus reducing the risk of PES fiber damage due to high temperatures at high performance operation.