With the objective of boosting ring spinning productivity, a new tandem spinning system combining air-jet and ring spinning technologies in continuous tandem is investigated. In this “air-plus-ring” tandem spinning system, a drafted roving strand as it emerges from the front roller nip feeds into a single- or dual-jet air nozzle where it is subjected to a vortex of compressed air, producing a pneumatically entangled, false-twisted, partially strengthened strand. This so-called prefabricated, air-bolstered strand continuously feeds into a standard ring spinning zone and is ultimately spun into a novel, single-component yarn. By spinning a few cotton and cotton-blend yarns with the lowest practical twist levels possible on both the tandem and conventional ring spinning systems, we show that a tandem spun yarn can be produced with a relatively lower (true ring) twist level than a pure ring spun yarn. To an extent, the tandem spinning's air-bolstering action reinforces the drafted fibrous strand, contributing to yarn formation and hence character. Since ring spinning productivity is inversely proportional to yarn twist level, the relatively lower twist level required in tandem spinning allows a proportionately higher yarn production speed (in some cases, up to 50% faster than the conventional ring spinning), while maintaining spindle speed at the traditional, optimum level imposed by the limiting traveler speed. Tandem spun yarns, however, are somewhat different from, and generally weaker than, conventional ring spun yarns. This paper briefly describes a prototype of the new tandem spinning system developed on a laboratory Spintester, and shows spinning parameters and properties of a few yarns produced on both the tandem arid conventional ring spinning systems, each employing the traditional (maximum) optimum spindle speed of 10,000 rpm for a given 5.0 cm (2 inch) diameter ring.
Thermophysiological wear comfort of viscose and tencel socks
