18—AN ANALYSIS OF THE AIR-JET YARN-TEXTURING PROCESS PART IV: FLUID FORCES ACTING ON THE FILAMENTS AND THE EFFECTS OF FILAMENT CROSS-SECTIONAL AREA AND SHAPE

Abstract

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of the Textile Institute in 1986, available online: http://dx.doi.org/10.1080/00405008608658417Fluid (drag) forces acting on filaments in an air-flow are theoretically analysed, and equations to calculate them are derived. Drag forces acting on filaments are shown to vary with the filament cross-section, the position of the filaments across the nozzle, and the local air velocity. Since finer filaments have a smaller inertial resistance to fluid forces and have lower stiffness, yarns with finer filaments are shown to be more suitable for air-jet texturing. Theoretical modelling of a lament as it emerges from the nozzle shows that, for filaments with identical linear densities, those with cross sections having reduced bending and torsional stiffness, such as elhpt1c cross-sections, may be more suitable for air-jet texturing