Performance Evaluation of Naturally Aged Silicone Rubber Polymeric Insulating Specimen with Nano TiO2 Filled Epoxy Coating

Polymeric outdoor insulators are seen as an attractive alternative to the porcelain/glass insulators due to their excellent hydrophobic property. Though the performance of polymeric insulators are superior as compared to their porcelain counterpart under contaminated conditions, with ageing hydrophobic property of these insulators decreases which in turn reduces their pollution withstand capability. In order to improve the pollution performance of the outdoor insulators, several coating techniques have been proposed in the literature. In the present work, aged polymeric insulator specimens have been coated with epoxy resin by embedding nano titanium dioxide (TiO2) as fillers in different weight percentage into the epoxy base. Dry, wet and pollution flashover experiments have been conducted on these specimens. The test results reveal that the performance of nano TiO2 filled epoxy coated specimens exhibit superior performance as compared to uncoated specimens under polluted condition. Further, when the polluted nano TiO2 filled epoxy coated specimens were exposed to UV light, the flashover voltage increased with significant reduction in pollutants deposited on their surface which implies that the nano TiO2 filled epoxy coated specimen exhibits self-cleaning property.