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 br eakdown in low-density polyethylene (LDPE) film was studied by thermog raphy. 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 hig her than that of an unoxidized one. It is considered that enhancement of the thermal process is a major factor of breakdown in the epoxy-fre e electrode system and that home-space charge and/or electron scatteri ng effect is dominant in the McKeown-type specimen.