Effect of Oxidation on Localized Heat Generation and Dielectric Breakdown of Low-Density Polyethylene Film

The effect of oxidation on localized heat generation and dielectric breakdown in low-density polyethylene (LDPE) film was studied by thermography. In the non-McKeown-type epoxy-free electrode system, localized heat generation of LDPE film leading to dielectric breakdown increased and breakdown strength decreased upon oxidation. In the McKeown-type specimen, however, the breakdown strength of oxidized LDPE film is higher than that of an unoxidized one. It is considered that enhancement of the thermal process is a major factor of breakdown in the epoxy-free electrode system and that homo-space charge and/or electron scattering effect is dominant in the McKeown type specimen.