Void Formation during Tensile Stretching in Irradiated Polyethylene Films

High density polyethylene (HDPE) films were prepared through cast film extrusion in a wide range of draw ratios. Applying higher draw ratios resulted in a stack lamellar morpholgy in the oriented films. The cast films were electron beam irradiated with irradiation doses of 40, 80 and 120 kGy. Gel content measurements and Fourier transform infrared spectroscopy (FTIR) confirmed cross-linking upon irradiation. Afterwards, both irradiated and non-irradiated films were stretched to evaluate void formation during tensile deformation. It was seen that in the films with higher draw ratios i.e. oriented films, void formation is enhanced. However, void formation is suppressed in the irradiated films. The scanning electron microscopy (SEM) images revealed no void formation in the cross-linked oriented films irradiated at high doses.