Some studies on hairiness reduction of polyester ring spun yarns by using air-nozzles during winding

Abstract

This paper reports on the hairiness reduction of polyester yarns at winding using air-nozzles. Three yarns of the same count were spun each from fibres of 1.0, 1.2 and 1.4 deniers respectively. Using a CFD (computational fluid dynamics) model, airflow inside the nozzles is simulated to explain the role of nozzle parameters viz., axial angle of air inlets and yarn channel diameter on yarn hairiness reduction during winding. Air drag forces acting on hairs are calculated. Transverse drag forces acting on hairs play a major role in bending the hairs. Vortex nature of air and air velocity profile inside the nozzle are the important phenomena in reducing yarn hairiness. Box and Behnken factorial design of experiments is used to optimize nozzles parameters, fibre denier, and air pressure to maximize the hairiness reduction. Axial angle of 45° for air inlets, 2.2 mm yarn channel diameter, 1.4 denier fibre, and 0.9 bar (gauge) air pressure are the combinations to get maximum reduction in S3 hairiness values of nozzle wound yarns. Fibre denier is a major influencing factor in reducing yarn hairiness.