Bakelite-style radio
Reactive plastics (thermosetting plastics) are plastics , the processing of which into products is accompanied by an irreversible chemical reaction , leading to the formation of a non-melting and insoluble material.
The most common thermosets based on phenol - formaldehyde , polyester , epoxy and urea resins. Usually they contain large amounts of filler - fiberglass , carbon black , chalk , etc. Thermoset materials are usually harder than thermoplastic materials.