INVESTIGATION OF THE STRUCTURED CHANGES IN HIGH-SPEED SPUN YARNS OF POLYAMIDE-6 BY MEANS OF WAXS EMPLOYING SYNCHROTRON-RADIATION

The melting and recrystallization of yarns of polyamide 6 spun at diff erent take-up velocities ranging from 3500 to 5600 m/min was investiga ted by means of wide-angle X-ray scattering (WAXS) employing synchrotr on radiation and by differential scanning calorimetry (DSC). It was sh own that the first peak in the double melting peak of the DSC-curves i s caused by the melting of the gamma-crystals. The melting point is in creased by approximately 5-degrees-C when the take-up velocity is incr eased from 3500 m/min to 5600 m/min. The addition of calcium stearate to the material has no effect on the thermal stability of the crystals , but seems to have some effect on the crystallization rate.