TIT# Investigation of the high speed spinning process of poly(ethylene
     terephthalate) by means of synchrotron X-ray radiation
AUT# Kolb, R.; Seifert, S.; Stribeck, N.; Zachmann, H. G.;
SOU# Polymer (2000), 41, 2931-2935
LOC# xv055
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ABS# Measurements of wide-angle diffraction during high speed spining of
     poly(ethylene terephthalate) (PET) have been performed using synchrotron
     radiation. The experimental set-up has been improved so that it became
     possible to determine the degree of crystallinity, crystallite orientation
     and fiber diameter along the spin line. For take-up speeds of $3600 m/min$
     and higher, the crystal reflections appeared at a distance of 40 cm from
     the spinneret, just after the necking region. The crystallization speed
     increases proportional to increasing take-up speed. for the take-up speeds
     investigated, this results in a constant crystallinity profile when
     measured as a function of the distance from the spinneret. The final
     fibers exhibited an exraordinarily high degree of crystallinity, which
     has been attributed to the high molecular weight of the polymer. Below
     $3500 m/min$, no crystallization and no necking could be detected up to
     a distance of 90 cm from the spinneret. This results showd that necking
     and crystallization were closely coupled. No orientation of the amorphous
     matrix prior to crystallization could be detected by means of X-ray
     diffraction. Moreover, the orientation of the crystallites was constant
     along the spin line.