Abstract:

In view of the problem of lower breaking strength and elongation of self-twist yarn, the fibers and those after being combined with other fibers suitable for self-twist spinning and fiber ratio were discussed, by comparing the breaking properties of self-twist yarns with that of ring spun yarns made by the same fiber. In comparison with the ring spun yarns,  breaking strength of wool, polyester, acrylic self-twist yarn decreased by 81.25%, 49.33%, 31.39%, respectively. Polyester and acrylic fibers can be used directly for the self twist spinning, but wool and ramie can't be used directly and must be compositely twisted with other fibers. Results of mechanical peoperties of wool/ polyester, ramie / polyester, acrylic / polyester composite self-twist yarn show that polyester fiber percentage should reach 60% or above in wool / polyester composite self-twist yarn to meet the processing requirement of afterward procedure, and for ramie / polyester it should reach 71% or more, with no limit for acrylic / polyester.

Key words: self-twist yarn, structural characteristic, breaking strength, breaking elingation, fiber composition