Moulding (molding) — shaping materials using molds

Materials and common types

Many materials can be moulded. Typical examples include thermoplastics and thermosets (for plastic parts), molten metals (casting and die casting), molten glass, rubber, and ceramic slip. Each material requires specific mould materials and process controls to manage temperature, pressure, and curing. For further reading about material selection consult material guides and process summaries.

Principal moulding processes

• Injection moulding: molten plastic injected under pressure into a closed mould — widely used for high-volume parts (injection details).
• Compression moulding: a charge of material is placed in a heated mould and pressed to shape (compression overview).
• Casting and die casting: liquid metal poured or injected into a mould to produce metal components (casting basics).
• Blow moulding and rotational moulding: used for hollow objects like bottles and tanks (blow & rotomoulding).

Tooling and mould construction

Moulds are typically made from hardened steel, aluminum, or composite materials depending on expected production volume and thermal or wear demands. Tooling design addresses part ejection, cooling channels, gate locations and draft angles so parts release cleanly. High-precision moulds may include inserts, slides or multiple cavities to produce complex or many identical pieces per cycle; for tooling resources see tooling notes and design references.

History and development

The basic idea of using cavities to shape materials dates back to ancient metal casting and ceramic molds. Industrial advances in the 19th and 20th centuries—steam power, standardized dies and later synthetic plastics—dramatically expanded moulding's role in manufacturing. Contemporary computer-aided design and CNC machining allow rapid mould prototyping and complex geometries; historical perspectives are available at historical overview.

Applications and notable examples

Moulding produces a huge range of everyday and specialized items: automotive components (body panels, engine parts, seals), consumer products (containers, toys, appliances), medical devices, and tyres — where shaped rubber is vulcanized inside moulds. Industries often combine multiple moulding methods within one product lifecycle; case studies and standards can be found via industry guide and case study links.

Distinctions and important facts

Note the difference between this topic and biological mould (fungus) — they are unrelated words. Also, spelling varies: "mould" is common in British English, "molding" in American English. Process selection balances cost, volume, material properties and tolerances. For regulatory, environmental and quality considerations consult standards and guidance.