AIR AND RING COMBINATION IN TANDEM SPINNING

With the objective of boosting ring spinning productivity, a new tande m spinning system combining air-jet and ring spinning technologies in continuous tandem is investigated. In this ''air-plus-ring'' tandem sp inning system, a drafted roving strand as it emerges from the front ro ller nip feeds into a single- or dual-jet air nozzle where it is subje cted to a vortex of compressed air, producing a pneumatically entangle d, false-twisted, partially strengthened strand. This so-called prefab ricated, air-bolstered strand continuously feeds into a standard ring spinning zone and is ultimately spun into a novel, single-component ya rn. By spinning a few cotton and cotton-blend yarns with the lowest pr actical twist levels possible on both the tandem and conventional ring spinning systems, we show that a tandem spun yarn can be produced wit h a relatively lower (true ring) twist level than a pure ring spun yar n. To an extent, the tandem spinning's air-bolstering action reinforce s the drafted fibrous strand, contributing to yarn formation and hence character. Since ring spinning productivity is inversely proportional to yam twist level, the relatively lower twist level required in tand em spinning allows a proportionately higher yarn production speed (in some cases, up to 50% faster than the conventional ring spinning), whi le maintaining spindle speed at the traditional, optimum level imposed by the limiting traveler speed. Tandem spun yarns, however, are somew hat different from, and generally weaker than, conventional ring spun yarns. This paper briefly describes a prototype of the new tandem spin ning system developed on a laboratory Spintester, and shows spinning p arameters and properties of a few yarns produced on both the tandem an d conventional ring spinning systems, each employing the traditional ( maximum) optimum spindle speed of 10,000 rpm for a given 5.0 cm (2 inc h) diameter ring.