Silicone Insulators Replacing Ceramic
Dow Corning has suggested using silicone rubber in high voltage insulators rather than traditional ceramic materials or organic composites. Silicone rubber's non-conductive chemical composition makes it a natural insulator, but it is silicone rubber's exceptional hydrophobicity -- the ability to cause water to bead on the surface of the insulation -- that sets silicone apart.
"Silicone prevents moisture from mixing with contaminants on the surface of the insulator, even after long-term exposure to electrical discharge, pollution, weather, and ultraviolet exposure," Kristen Mizell of Dow Corning said. "This helps reduce current leakage and flashovers, reduces maintenance, and extends service life."
Silicone rubber composite insulators do not require any cleaning under any environmental conditions and can even suspend maintenance for more than 10 years.
Ceramic materials and organic composites start out with good hydrophobicity, but over time electrical discharges can erode and damage the insulating material, leading to failure of the insulator, Mizell said.