False-twist texturing with water-jet twister/cooler: effect of water pressure on textured yarn properties

Abstract

The objective of this research work was to investigate the effect of water pressure on the properties of false-twist textured yarn produced using an innovative false-twist texturing system with waterjet twister/cooler and superheated steam heater. Commercial texturing speed of 800 m/min was selected for this paper so as to establish that this innovative method can be used for false twist texturing successfully. This method replaces the contact heater of a standard false-twist machine with a ‘super-heated steam heater’ and ‘the normal false-twisting device and cooler’ replaced with a ‘water-jet twister/cooler’ combined into one unit, so as to reduce the thread-line length and to increase the production speed significantly. The new heating, twisting and cooling unit is only one metre in length. The reduced thread path has significant advantages when the surging speed is considered. The shorter thread path reduces thread instability and so higher texturing speeds can be achieved. Since the water-jet twisting is virtually friction-free, and has no mechanical moving parts, the production speed can be increased avoiding filament breaks. Results show that this innovative method of false twist texturing can achieve high bulk levels above 40% with good process stability at 800 m/min. Water pressure has a significant positive correlation with twist level and bulk percentage and significant negative correlations with textured yarn tenacity and elongation. When the water pressure is increased, the level of twist imparted to the yarn and the bulk level increase to a maximum. Overall, the results show that the new method of false-twist texturing is capable to produce false-twist textured yarn with success.