Effect of process and nozzle structural parameters on the wrapping quality of core-spun yarns produced on a modified vortex spinning system

Abstract

Vortex core-spun yarn containing a metal wire has a broad application prospect owing to the combination of its fasciated structure, durability, comfort, and its electrical properties. In this paper, three-dimensional numerical simulations on the flow characteristics inside the nozzle of a modified vortex spinning system for producing core-spun yarns are carried out to investigate the effect of some process and nozzle structural parameters—the nozzle pressure, distance between nozzle inlet and spindle, and protrusion length of the filament feeding tube—on the flow field. Using a machine vision system, experiments are also conducted to investigate the effects of these parameters on the wrapping defects of the vortex core-spun yarns which are then analyzed based on the simulation results. The number of wrapping defects on the yarn greatly decreases as the nozzle pressure increases from 4 × 105 Pa to 5 × 105 Pa. As the distance between nozzle inlet and spindle increases, the number of wrapping defects on the yarn first decreases and then increases. The effect of protrusion length of the filament feeding tube is found to be insignificant. This experimental and numerical study can provide a feasible way for optimizing the quality of the core-spun yarn produced on the modified vortex spinning system and analyzing the mechanism of the effects of parameters.