Abstract
The evolution of spinning technology was focused on improving productivity with good quality of yarns. More detail spinning technology according to mixing of various kinds of fibre materials on the air vortex spinning system is required for obtaining good quality yarns. This paper investigated the physical properties of air vortex yarns compared with ring and compact yarns using PTT/tencel/cotton fibres. It was observed that unevenness of air vortex yarns was higher than those of ring and compact yarns, which resulted in low tenacity and breaking strain of air vortex yarns. Initial modulus of air vortex yarns was higher than those of ring and compact yarns. Yarn imperfections of air vortex yarns such as thin, thick and nep were much more than those of ring and compact yarns. These poor yarn qualities of air vortex yarn were attributed to the fasciated yarn structure with parallel fibres in the core part of the air vortex yarn. However, yarn hairiness of air vortex yarns was less and shorter than those of ring and compact yarns. Thermal shrinkage of air vortex yarns were higher than that of ring yarns, which was caused by sensible thermal shrinkage of PTT fibres on the bulky yarn surface and core part of air vortex yarns.