CLEAPSS DT - Supporting practical work in science, technology and art

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In both processes, a thermoplastic sheet is clamped around its edges and heated. In vacuum forming, the air between the mould and the work is evacuated. The mould is then elevated into the sheet. Atmospheric pressure on the material then presses it onto the mould.In pressure forming, air pressure is applied to the underside of the hot sheet forming it into part of a sphere.Some plastics must be pre-heated to dry them.
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