The characterization of nylon 6 filaments by x‐ray diffraction

A method is described for calculating crystallinity indices and crystalline orientation functions for the α and γ components of the crystalline phase of nylon 6 filaments using wide‐angle x‐ray diffraction (WAXS) analysis. The method is shown to be applicable to a wide range of filament samples (“conventional” as‐spun, fast spun, drawn, and annealed) even when only a single broad diffraction maximum is observable from the WAXS photograph. The component indices can be used to illustrate differences present in the filament microstructure which would be unobservable if a total crystallinity index, such as that determined by density, were determined alone. For example, the initially mixed α–γ structure is retained in low‐temperature drawing (75–150°C) of nylon 6 fiber, but the predominantly α form is produced at higher draw temperatures.