Direct optical observation of polyethylene microstructures under field and temperature conditions, before any degradation

Abstract

An approach was made to understand the role played by the microstructure of a LPDE in the ageing process of this material under electric stress. An optical observation and an image treatment of the structure evolution reveal a physical behaviour comparable to a "fatigue process". Although the applied field was about 35 times the working field of a cable we have not observed any tree in the samples.