30—an Analysis of the Air-Jet Yarn-Texturing Process Part V: The Effect of Wetting the Yarns

31—an Analysis of the Air-Jet Yarn-Texturing Process Part Vi: The Mechanism of Loop Formation

“…In the previous parts of this series of papers [1][2][3][4][5] , a brief history of developments in the air-jet texturing process 1 Was given together with an account of an experimental investigation of the air-flow 2 and of the investigation of filament behaviour during texturing 3 Fluid forces acting on the filaments were analysed and possible effects of filament cross-sections on the texturing process considered 4 The effects on the texturing process of wetting the yarn were also investigated 5 .…”

The Mechanism of the Air-Jet Texturing: The Role of Wetting, Spin Finish and Friction in Forming and Fixing Loops

“…The differences between the supply yarn and yarns simulating dry and wet texturing conditions are found to be insignificant, as shown in Table IV. However the lubricating effect of wetting the filament yarn to reduce friction has been very clearly demonstrated by Acar et al [7] in an earlier study and similar reduction in kinetic friction should also be observed when wet tested. Table V shows the measured values of the stabilising tension during wet and dry texturing.…”

“…They analysed the positions of filament using instantaneous single frame still photographs and high-speed cine-photography observing the region just outside the air-jet texturing nozzles [7]. The latter provided a continuous record of the yarn motion and showed the filaments emerging from the nozzle and being drawn at right angles (by the take-up rollers).…”

“…To prove this hypothesis Acar et al [7] designed a series of experiments. The tension in the filament yarn prior to its entrance into the nozzle is normally the result of the fluid forces acting on the yarn minus the friction forces that oppose the yarn motion.…”

“…Acar et al [7] assumed that the interaction between a moist yarn and the air stream creates a fine mist of small water droplets mixing into the air flow. They used homogeneous two-phase flow theory to calculate the momentum that is extracted from the airflow to maintain the speed of the water droplets.…”