• biodegradable;
  • copolyester fibers;
  • extrusion;
  • rheology;
  • X-ray;
  • statistical modeling


By using factorial experimental design, a range of crystallographic orders for as-spun linear aliphatic–aromatic copolyester fibers have been characterized with the aid of wide angle X-ray diffraction measurements. Full-Width Half-Maximum of an X-ray scattering profile (FWHM) has been quantitatively assessed as responses to polymer grades denoted by melt flow index (MFI) and to extrusion temperature zones in the extrusion equipment used to produce the as-spun fibers. With the advantages of the factorial experimental design in the development of fiber process technology, the enhanced statistical approach specifies the direction of change of the polymer's melt flow index and extrusion temperature profile for increasing or reducing crystallographic order. The produced as-spun aliphatic aromatic copolyester fiber is an environmentally-friendly attractive, alternative to conventional chemical fibers for different applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011