Effects of modified air quenches on the high‐speed melt spinning process

Abstract A high molecular weight polyethylene terephthalate was spun into fibers in the speed range from 3,000–7,000 mpm. The effect of modifying threadline dynamics through a combination of enhanced and/or retarding air quenches on the resulting spinning performance, fiber structure, and mechanical properties was examined. Particular combinations of these threadline temperature profile modifications were shown to result in significant improvements in spinning performance and as‐spun fiber structure. Extensive characterization of select fiber samples revealed higher orientation and crystallinity, larger crystal dimensions, and greater mechanical properties. These results also demonstrated the ability to provide continued improvement in fiber properties at very high take‐up speeds where typically a decline is observed. It is concluded that the threadline temperature profile can be altered in such a way as to significantly enhance the resulting spinning performance and fiber structure over a wide range of take‐up speeds.