SIMPLE ONLINE X-RAY SETUP TO MONITOR STRUCTURAL-CHANGES DURING FIBER PROCESSING

We demonstrate that on-line X-ray characterization during fiber proces sing can be carried out using a low-power X-ray generator and an image plate detector. Two fiber processes using 66-nylon were chosen as exa mples: high-temperature drawing at different ratios (3.5-5.0 X) and me lt spinning at moderate speeds (450 and 1,200 mpm). For the draw measu rement, useful diffraction images were obtained in a reasonable time f rame (30 min). These patterns were equal in quality to static in-labor atory images and sufficient for quantitative analysis. Results showed significant differences in structure between on-line and off-package s amples. The crystal density was found to be lower but the crystal orie ntation was found to be higher as draw ratio increases. The on-line sp inning image was found to be similar to those obtained by synchrotron X-ray measurements, which confirm the development of two-dimensional c rystals having a hydrogen bonding characteristic distance during spinn ing. Finally, several ways to improve the demonstrated on-line setup d esign will be discussed. (C) 1996 John Wiley & Sons, Inc.