Study on the restoration methods of surface insulation performance for epoxy resin post-insulators

Epoxy resin post insulators, when operated in high-humidity environments without regular cleaning, often suffer from a decline in insulation performance after several years of service. This deterioration is primarily caused by insulation aging of the epoxy material and the accumulation of surface contamination, which may lead to discharge events and pose a threat to the safety of power systems. This study presents a preliminary investigation into methods for restoring the surface insulation performance of epoxy resin insulators. Several restoration approaches, including oven drying, solvent immersion, and wiping, were applied to aged insulators. The effectiveness of these treatments was evaluated through surface resistance measurements and Fourier-transform infrared (FTIR) spectroscopy. The results indicate that: Drying significantly improves surface resistance by removing adsorbed moisture. All three cleaning methods (immersion in anhydrous ethanol, immersion in an organic cleaning agent, and wiping with cable cleaning tissue) led to substantial surface resistance restoration, although through different mechanisms and with different applicability. FTIR spectroscopy confirms hydroxyl group reduction after cleaning, with no damage to the chemical structure of the epoxy matrix.