Heat flow is inevitable when objects with different temperatures touch. If one of these objects is meant to stay cool, high temperature can be damaging. Thermal insulation is not only meant to prevent heat flow to sustain equipment, but reduce environmental impact and avoid heat loss to save money. Thermosets, or thermosetting plastics, are one of the most reliable and frequently-used thermal insulators.
Thermosets are polymer materials that are irreversibly cured. The curing process hardens a substance through a constant combination of heat and pressure. Heat begins the transformation from liquid to solid, whereas pressure prevents voids and bubbles from forming in the material. As a result, curing causes a strong molecular bond within thermosetting plastic molding and establishes its physical properties so that it cannot be melted back to a liquid. This also means if thermoset products are exposed to intense heat, they will not drip and lose their forms. Because of this, they are especially effective as electrical insulators.
Electrical equipment, such as a cable, typically produces large amounts of thermal energy because of a high number of active electrons in a small space. However, these hot temperatures neither weaken the stability nor damage the structure of thermoset materials. For example, vulcanized rubber in car tires is a thermosetting plastic. Though tires can hit high heat levels, they do not mold into a new shape.
This is why a product such as extrusion molding, which is a thermoset, is an ideal insulator for electrical cables. Bakelite, another thermosetting plastic, has been used to make electrical insulators for a variety of machines since its discovery in the early 1900s. Many metal processing plants also rely on thermosets as electrical insulators because of the hot environment.
Due to their durability and heat-resisting qualities, thermosetting plastics are also ideal for permanent mechanical components and products that must endure severe weather conditions.