Asked by: Mark Warmsley, Southampton
Most of the plastics we use are either thermoplastic or thermosetting.
Thermoplastics include acrylics, nylon and polyethylene (polythene). As you heat them up they get soft, so they can be shaped into any form you like, which also makes them easy to recycle. Milk containers can be melted and reformed into furniture, plastic water bottles become fleece jackets, and hard bottle tops can get a new lease of life as storage boxes.
Thermosetting plastics, like Bakelite or polyurethane, are different because they harden as you heat them. Once they have set, you can’t melt them. This makes thermosetting plastics almost impossible to recycle.