Silicone is widely used in non-ceramic insulators, why silicones widely used for Polymer Insulator? We mainly talk about the properties of silicones for polymer insulators
Thanks to their chemical structure, silicones are extremely suitable for applications in the transmission and distribution sector. They have an impressive spectrum of electrical, physical, mechanical and chemical properties.
Hydrophobicity
Compared to other materials, silicones exhibit very good, long-lasting water-repellency, also known as hydrophobicity. Insulating components made of silicone rubber compounds still repel water after many years. The leakage current is minimized and thus pollution flashover is prevented. This also applies to very dirty surfaces, because the water-repelling effect is transferred to the pollution layer. This is known as hydrophobicity transfer. Such an effect can also be achieved by treating glass and porcelain insulators with a silicone coating, making repeated cleaning processes unnecessary.
Resistance to UV Radiation and Weathering
Compared to other materials, silicone elastomers are particularly resistant to UV radiation. Even harsh weather conditions, as found in coastal regions or deserts, have little effect on their properties. For example, in an accelerated weathering test, the silicone rubber 310 showed only slight changes in the mechanical and hydrophobic properties after 3,000 hours.
Low Flammability
Silicones only ignite at very high temperatures. This makes them particularly safe in operation. Even if they did ever catch fire, they would not produce any toxic gases. This is why they are the ideal choice for applications subject to strict fire safety requirements, for example in subways and high-rise buildings.
Elasticity
Silicone insulating materials are extremely elastic. This facilitates installation and makes for novel installation techniques, e.g. cold shrinking on cables.
Dielectric Properties
Silicones have high electrical resistivity and a low dielectric loss factor. They exhibit extremely low electrical aging compared to other insulating materials.
Temperature Stability
Owing to their chemical structure, silicones have particularly high thermal stability. Another benefit of silicones is their high temperature resistance. For example, silicones maintain their elasticity down to -45 °C, which makes them particularly suitable for use at high altitudes and in polar regions.