A study on breakdown phenomenon identification of polymer films

The process of leading to breakdown of low-density polyethylene (LDPE) film and high-density polyethylene (HDPE) film was investigated, with particular attention on the breakdown phenomenon identification. From the pictures of breakdown point obtained by a monocular video zoom microscope, it can be observed that the shape of breakdown area was almost identical to the type of electrodes. Meanwhile, the mathematical statistics were used to analyze the obtained results. The study revealed that the DC breakdown voltage of HDPE was higher than that of LDPE. The breakdown diameter and area of HDPE was bigger than that of LDPE. To the needle-plane electrode, the diameter and area of breakdown point with the polymer film at the plane electrode was bigger than that at the needle electrode, and that at the middle of gap distance was between them. To the sphere-plane electrode, the diameter and area of breakdown point with the polymer film at the sphere electrode was bigger than that at the plane electrode, and that at the middle of gap distance was between them