Plastics Processing

Moulding, casting and forming plastics

Working with Plastics

Plastics are synthetic materials that can be moulded when heated. Thermoplastics (like PET, PVC, polypropylene) can be reheated and reshaped — they are recyclable. Thermosets (like epoxy) set permanently — they cannot be remoulded. Processing includes moulding, vacuum forming, cutting and welding.

Example

Plastic Processing Methods

• Injection moulding: melted plastic forced into a mould (toys, containers) • Blow moulding: air inflates hot plastic tube into a mould (bottles) • Vacuum forming: sheet heated and sucked into a mould (packaging) • Extrusion: plastic pushed through a shaped hole (pipes, tubing) • 3D printing: building up layers of plastic (prototypes, parts) Recycling codes: Look for numbers (1-7) in triangle on plastic items

Note

Remember

Plastic pollution is a major environmental problem — over 8 million tonnes enter oceans annually. Design responsibly: use minimum plastic, choose recyclable types, design for disassembly. In SA, plastic collection and recycling creates jobs while reducing pollution. Always recycle!

Key Vocabulary

ThermoplasticPlastic that can be reheated and reshaped (recyclable)

ThermosetPlastic that sets permanently and cannot be remoulded

MouldingShaping melted material using a mould

Vacuum formingShaping heated plastic sheet by sucking it into a mould

SASL Avatar

Loading avatar...

1 / 4

Thermoplastic

Speed: