Process-structure-property relationship of polyester-cotton MVS yarns: Part I -Influence of processing variables on yarn structural parameters

Abstract

The influence of twisting jet pressure, delivery speed, nozzle distance, yarn linear density and yarn composition on the structural parameters of polyester-cotton yarns spun on Murata Vortex Spinner (MVS 810) has been studied. It is observed that the MVS yarns have about 50-60% core fibres and remaining as wrapper or wild fibres. The structure of MVS yarn

has been classified into four main categories, viz. tight wrappings, long wrappings, irregular wrappings and unwrapped. The tight wrappings are found to increase with the increase in jet pressure but at very high jet pressure, they get converted into irregular wrappings. The long wrappings increase with the nozzle distance while unwrapped structure decreases with both

jet pressure and nozzle distance up to a certain level. The finer yarns have low proportion of core fibres. The wrapper and wild fibres increase with the jet pressure but at very high jet pressure of 6.0 kg/cm², the wild fibres increase significantly. An increase in delivery speed leads to a further increase in wild fibres.