Interaction of Corona with Dielectric Material Until Damage

A study of polyethylene terephthalate (PET) and polypropylene (PP) treated by corona discharge for a short time is presented. Different techniques of analysis such as inverse chromatography, infrared spectroscopy, loss tangent and electric strength were used. Working at 50 Hz with a gap of 2 mm and different gases, the analysis of the polymer after treatment has shown that a limit in the transformation of the surface may be considered. Thus a critical time is defined between a pure transformation and a degradation. This latter phase is also studied with a cross linked polyethylene (XLPE). The infrared analysis and electric strength measurements have shown the role played by the relative humidity present in air.