Rheological and thermal properties of the poly(epsilon-caprolactone) (PCL) polymer are presented in Section 1.1. Section 1.2 summarizes results of melt-spun PCL filaments. Specifically, we show the necking point stabilization during high-speed online drawing in Section 1.2.1, filament morphology in Section 1.2.2, wide-angle X-ray diffraction (WAXD) fitting results in Section 1.2.3, WAXD patterns of aged fibers in Section 1.2.4, crystallinity analysis in Section 1.2.5 and small-angle X-ray scattering (SAXS) analysis results in Section 1.2.6. Details about the materials, experimental and analytical methods are given in Section 2. Of particular interest may be the simulation and fitting procedures of 2D WAXD patterns, which are summarized in Section 2.7.2. For more information see the publication by Selli et al. 'Mesophase in melt-spun poly(epsilon-caprolactone) filaments: structure-mechanical property relationship' . (C) 2020 The Authors. Published by Elsevier Inc.