On the neck‐like deformation in high‐speed spun polyamides

Abstract

Abstract The neck‐like deformation process occurring in high‐speed melt spinning of polyamide 66 and polyamide 6 filaments was investigated at take‐up speeds of 4200 to 5500 m/min by on‐line laser light scattering, thermographic contrast compensation, and wide‐angle X‐ray scattering (WAXS) measurements. New information about the onset of crystallization along the spinline was obtained by measuring simultaneously diameter and temperature profiles in the neighborhood of the neck. Crystallization rates, as a function of take‐up speed, are estimated for both polyamides. Based on the present experimental results of diameter profiles, temperature profiles, and WAXS patterns, a picture of the physical mechanism responsible for the neck‐like deformation of high‐speed melt spun polyamides is proposed. © 1993 John Wiley & Sons, Inc.