insulatorsmaterials

Insulator materials are substances with high electrical resistance and low electrical conductivity, used to prevent the unintended flow of electricity and to provide mechanical support in electrical systems. They also play a role in reducing heat transfer, so some materials function as thermal insulators in buildings and equipment. In electrical applications, insulators must withstand voltage, resist surface leakage, and endure environmental contamination, while maintaining mechanical strength and aging resistance. Thermal insulators are chosen for low thermal conductivity and adequate fire performance, weight, and durability.

Common electrical insulator materials include ceramics such as porcelain and glass; polymers such as cross-linked polyethylene, polyvinyl chloride, epoxy resins, and silicone rubber; and composite materials used for outdoor insulators. Porcelain and glass are rigid, have high dielectric strength, and excellent temperature stability but can be brittle. Polymers are lighter and resistant to contamination and weathering but may age under UV exposure and heat. Performance depends on moisture, surface condition, and aging.

Thermal insulating materials include mineral wool, fiberglass, polyurethane and polystyrene foams, aerogels, cellulose, cork, and natural fibers. They are selected for low thermal conductivity (k), low density, and favorable fire characteristics. Applications include building envelopes, refrigerators, pipes, and industrial equipment. Some materials provide both electrical and thermal insulation, but compatibility of properties must be considered to avoid safety risks or performance tradeoffs.

Selection depends on service temperature, environmental conditions, mechanical load, and cost. Insulators are evaluated for dielectric strength, volume and surface resistivity, moisture absorption, and fire performance, with testing standards issued by IEC, UL, and other authorities.