Fabrication and Properties of Self-crimp Side-by-Side Bicomponent Filaments Composed of Polyethylene Terephthalates with Different Intrinsic Viscosity

Self-crimp side-by-side bicomponent filaments (SBSBFs) were prepared via melt spinning using two kinds of polyethylene terephthalate (PET) with great disparity of intrinsic viscosity. The influence of the volume ratio on the surface morphology, crystallinity, crimping properties, mechanical properties and shrinkage properties of the bicomponent filaments was investigated using wide-angle X-ray diffraction, a differential scanning calorimetry (DSC), scanning electron microscope, etc. As the proportion of the low-viscosity component increases, the shrinkage in boiling water or hot air, as well as the shrinkage force and the sonic orientation factor of the bicomponent filaments decrease, and the DSC heating curves change from double peaks to a single peak. These phenomena should be ascribed to the high orientation and low crystallinity of the high-viscosity PET component and low orientation and high crystallinity of the low-viscosity PET component. Moreover, the crimp property of the bicomponent filament with a volume ratio of 50:50 is superior to those with other volume ratios.