A statistical investigation of dielectric breakdown of low-density polyethylene

Experiments were conducted using two kinds of LDPE film samples with three film thickness to examine dielectric breakdown of low-density polyethylene. Experiments were performed using a parallel-plate electrode system with three different electrode diameters. Results were analyzed applying Weibull statistics. Weibull statistics showed great differences between LDPE samples in values of median breakdown strength, shape, and location parameters. The median breakdown strength and the shape and location parameters of breakdown strength of samples prepared from cable-grade LDPE pellets were confirmed to be greater than those of samples from normal-grade LDPE. Impurities existing in both films were counted to examine causes of breakdown. Detailed results are assessed in connection with the dielectrics' breakdown strength.