摘要 |
Plastics foil is shaped in a deep drawing apparatus by being placed in a mould, while the foil is below its deformation temperature, having heated wall surfaces and by applying a pressure differential to the foil so that it progressively stretches and contacts the mould wall. The progressive heating and stretching of the foil ensures that the corners of the moulded article are not thinner than the remaining portions of the moulded article, thus reducing the amount of plastics material necessary for an article of given strength.
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