ONLINE MEASUREMENTS OF ORIENTATION INDUCED CRYSTALLIZATION OF PET DURING HIGH-SPEED SPINNING

An experimental set-up in the synchrotron radiation beam was construct ed for performing wide angle X-ray scattering (WAXS) on-line measureme nts, during high speed spinning of poly(ethylene terephtalate) (PET). In order to detect the very weak scattering of the thin filaments (= 2 6 mu m diameter) the capton windows of the vacuum tubes were removed a nd the air was replaced by helium. In this way it became possible to m easure the development of crystal reflections as a function of the dis tance from the spinneret. A comparison of the results with correspondi ng on-line measurements of the fibre diameter indicates that crystalli zation starts at the beginning of the necking zone. Copyright (C) 1996 Elsevier Science Ltd.