Insulators

An insulator is a material or system that reduces or prevents the transfer of energy between objects or environments. Insulators limit heat flow, electrical current, or sound transmission to improve safety, efficiency, and comfort. They are commonly grouped by the energy they block: electrical, thermal, and acoustic.

Electrical insulation slows or stops current flow. Important properties include high resistivity, high dielectric strength, and low dielectric loss. Common insulators are glass, porcelain, plastics (such as polyethylene and silicone), epoxy resins, and rubber. They protect equipment, separate conductors, and prevent faults. Performance can degrade with moisture, temperature, or aging, increasing the risk of breakdown or leakage.

Thermal insulation minimizes heat transfer by conduction, convection, and radiation. Materials with low thermal conductivity and often porous structure are used. Examples include fiberglass, mineral wool, expanded polystyrene, polyurethane foam, aerogel, wood, and cork. Applications include buildings, appliances, refrigerated spaces, and clothing. Methods range from insulating layers and reflective barriers to vacuum panels.

Acoustic insulation reduces sound transmission. It relies on mass, damping, and porosity to absorb or block sound. Common materials include mineral wool, fiberglass, acoustic foams, and mass-loaded vinyl, used in walls, ceilings, automotive cabins, and studios.

Selection depends on environment, temperature, moisture, mechanical stress, safety, and cost. Designers consider durability, rating, and compatibility with other materials.