Evolution of the surface layer appearing with the corona ageing of epoxy samples

摘要

The work reported here is suggests a possible model, based on observations on epoxy samples, to explain the bump formation described in the litterature on corona treatment of polymers. It does not pretend to be a complete treatment of the subject. Condensation processes under a corona discharge are a complex problem, and so are the chemical reactions occuring in coronas. The electrical measurements suggest that corona treatment alone can not lead to a sufficient surface conductivity to induce dry band formation mechanism on an insulator surface. Corona treatment alone rather seems to avoid charge permanence on the surface, thus increasing flashover voltage. However, the corona-induced wettability increase can enhance dust fixation on the surface and accelerate dry band formation.