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Ready, set, thermosets

Thermosetting polymer materials are tough! Thermoset materials are different than thermoplastic materials in that once the thermosets are processed, they form irreversible bonds that can’t be reclaimed and reused like thermoplastics, which can be re-melted and re-processed into other parts. The high strength-to-weight ratio of thermosetting materials makes it a good choice when high-strength but lighter weight is needed – particularly in transportation applications – as it is 35 percent lighter than steel parts of the same strength.

Thermoset materials include polyester resins (the most common), vinyl ester, epoxy, phenolics, and urethane. Uncured they are in a liquid state that allows for the impregnation of reinforcing fibers. Fiber reinforced composites (FRP composites), use a thermosetting resin as the matrix which holds the structural fibers in place. These fibers can be fiberglass, carbon or Kevlar, making the parts that are molded of thermosetting materials tough, heat/temperature resistant (flame retardant) and resistant to solvents and corrosives.

That makes thermoset parts ideal for applications that see high temperatures, such as engine components, electronic and electric applications in aircraft, and heavy machinery. Thermoset materials’ dielectric properties provide excellent electrical insulation, which is why this material is used for electrical insulators and other equipment found in electrical transfer stations.

Molded-in color means that it is scratch resistant because of the surface hardness, which exceeds that of thermoplastic materials. And the color is as permanent as the parts – it can’t be worn off or melted off.

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