Statistical investigation of dielectric breakdown of LDPE

The statistical characteristics of the dielectric breakdown of low-density polyethylene (LDPE) were investigated through experiments using two grades of LDPE film. The experiments were performed using a parallel plate electrode system with three electrode diameters and three film thicknesses. The breakdown strength data obtained was analyzed by Weibull statistics, and a noticeable difference was observed in the Weibull parameters of breakdown strength for the two film types examined. Based on the statistical results and correlation with microscopic observations of the films, the electric strength of LDPE film is found to be closely related to the abundance of impurities in the material.