Vacuum forming

Process:   A preformed sheet of material is placed in a mould then warmed and sucked or pushed into shape using a vacuum.  Neither high heat nor pressure is required so moulds can be made from cheap materials such as MDF or cast aluminium.

Introduced:   1890 for use with cellulose nitrate.

Plastics:   Most sheet thermoplastic materials, for example cellulose nitrate, cellulose acetate, polystyrene, polypropylene, polyvinyl chloride, acrylonitrile butadiene styrene, and polycarbonate.

Marks:   None.

Tooling cost:   Low.

Production volume:   Suitable for low quantities or even one offs, but can be mechanised to speed up the process.

Uses:   Shallow forms: baths and boat hulls, bowls, margarine and yogurt pots.