Spinning speed–throughput rate relationships for polyester,nylon, and polypropylene fibers

The relationship between spinning speed and throughput rate has been investigated for fibers having the same fiber denier in the drawn state when produced by melt spinning of poly(ethylene terephthalate), nylon 6, and polypropylene polymers over a range of take-up speed (750–3000 m min^-1) and throughput rate. To understand the structural origin of the relationship, a limited amount of characterization of structure and properties of the as-spun and drawn fibers was also done. A comparison of the results for the three polymers shows that while the increase in productivity with increase in spinning speed is relatively less for polyester and nylon 6, it is quite high for polypropylene. The birefringence data show that while molecular orientation increases rapidly with increasing wind-up speed in polyester and nylon 6, the rate of increase is relatively less in the case of polypropylene. The possible reasons for the observed differences in behavior are discussed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1773–1788, 1997