Welding of Plastics (X)

Study on Necking of Thermoplastics

Abstract

To trace the cause of the phenomenon of necking, it is essential to make clear the physical, chemical and mechanical relations in the microstructure of thermoplastics. With a view to clarifying the effects of mechanical properties and microstructure on deformation and fluidity of thermoplastics, and elucidating the necking of plastics materials, a study was made by tension tests, X-ray diffraction tests, and specific viscosity tests, in which X-ray diffraction tests were done with the parent material, specimens welded by various gases, Co⁶⁰ γ-ray radiated specimens, tests on each tensile fracture, etc., in high pressure polyethylene.