Effect of surface treatment of fillers on deterioration of silicone rubber housing materials in salt fog ageing test

Salt fog ageing test is widely conducted for evaluating anti-tracking and/or anti-erosion performance of housing materials for polymer insulators. We have investigated the effect of surface treatment of fillers on the deterioration of silicone rubber housing materials for polymer insulators. Cyclic salt fog ageing test was conducted fundamentally based on the specification given by the CIGRE WG 15-04. High temperature vulcanized silicone rubber rod type specimens having different amount of fillers with and without surface treatment were used in this investigation. After 50 test cycles, erosions were observed on the specimens without surface treatment. The specimens with surface treatment showed lower leakage current and cumulative charge than the specimens without surface treatment. Larger reduction of hydrophobicity can be seen on the specimens without surface treatment compared with the specimens with surface treatment.