How is plastic shaped?

Plastic is shaped in many ways. The liquid can be pushed through a nozzle to form sheets, tubes and fibres. Molten plastic may be poured into moulds. More complicated shapes can be made through vacuum farming. In this process, a sheet of warm plastic is kept over a mould. The air is then sucked from under it. This causes the sheet to be pulled firmly against the sides of the mould. When the plastic cools, it retains the mould’s shape.