REDUCING YARN HAIRINESS WITH AN AIR-JET ATTACHMENT DURING WINDING

The winding process tends to promote yam hairiness, a detrimental effe ct that can be significantly reduced by adding a properly arranged air -jet nozzle. This paper examines the mechanisms of hairiness reduction with an air jet during winding. The results indicate that the directi on of the majority of protruding fibers and that of the air vortex pla y an important role. They also suggest that yam hairiness can be best reduced if the gyrating air current lowers the twist level before the yam enters the jet, and if the air flow spirals along the yam in a gen eral direction opposite that of the yarn traverse to suppress the majo rity of protruding fiber ends. Wrapping of protruding fiber ends aroun d the yam and removal of ''wild fibers'' by the swirling air current a re believed to be responsible for the reduction in yam hairiness, and tucking of fiber ends into the yam structure may also occur under cert ain conditions.