A contribution to the study of long term electrical treeing tests on polymers

The preliminary results here presented indicate, for the LDPE used, in the ranges of time and voltage explored, with the specimens and electrodes geometry adopted, using steel pins, that the parameter “treeing inception voltage” increases with ageing. Moreover the shape of the “life curve” obtained for treeing inception, could be consistent with the existance of a threshold for voltages lower than 0.5 the initial average treeing inception voltage. Therefore further support to the above findings is expected by additional experiments under way.