An Introduction to Pneumatic Alternate Twist Ply (ATP) Yarn Technology
An ATP yarn is a plied yarn, where the twist direction alternates every few feet To ensure yarn stability at the twist reversal locations, the fibers must be interconnected or bonded. An optimum ATP yarn has a uniform square wave twist distribution (abrupt change from S to Z direction twist), a minimum bond length (about 0.1) and a low bond frequency. The ATP process can run up to ten times faster than conventional ply twisting such as cabling or ring spinning. The speed advantage results from the fact that the paths taken by the individual fibers are topologically equivalent to that of a simple parallel array. This geometric feature also permits the process to be run without capturing either the feed or output yarn packages-an important limiting factor in conventional processes. Furthermore, ATP yarns are not limited to two plies as in the case of cabling. Current ATP processes (Repco, Gilbos, Belmont) run at constant velocity. The Drexel Pneumatic ATP process (originally developed by Du Pont) can be run with profiles of both axial and rotational speeds. This feature, the focus of this study, can be engineered to ensure quality twist distributions and short bond lengths. Another important feature of this process is ultrasonic welding-a method of achieving short, stable bonds. Our goal is to optimize the processing of ATP yarns using both experimental and mathematical techniques. A mathematical process simulation, based on solutions of the underlying differential equations, was developed to determine process conditions needed for a square wave twist distribution. Experiments, using different yarn speed profiles, substantiate the mathematical model.
An ATP yarn A square wave twist distribution Conventional ply twisting
Donia Elkhamy Peter Popper Paul Yngve Frank Ko
Materials Science and Engineering, Drexel University, Philadelphia, PA, 19104 , USA Peacock Sales, Wilmington, DE, USA Innovative Technology, Prosperity, SC, USA
国际会议
杭州
英文
1-9
2006-08-22（万方平台首次上网日期，不代表论文的发表时间）