Process-structure-property relationship of polyester-cotton MVS yarns : Part II - Influence of process variables on yarn characteristics

Abstract

The influence of twisting jet pressure, delivery speed, nozzle distance, yarn linear density and yarn composition on the characteristics of polyester-cotton MVS yarns has been studied. Contrary to MJS yarns, the coarser yarns are stronger than the finer ones due to the higher proportion of load-bearing core fibres. The twisting jet pressure has a direct effect on the

tensile characteristics of polyester-cotton MVS yarns and the optimum pressure is dependent on yarn linear density. Moreover, the use of excessive high jet pressure adversely affects yarn tensile characteristics. The use of higher nozzle distance improves the yarn tenacity; the latter, however, deteriorates at very high nozzle distance. A higher delivery speed produces weak, less rigid, less uniform and more hairy yarns.