Injection moulding method

摘要

An injection moulding method provides products with excellent transcription and gloss level. Immediately after a resin is injected into a die cavity (1), carbon dioxide gas is injected to move back the surface skin layer to form a space (13) between the resin and the die surface (1) whereby growth of the skin layer is slowed down. At the same time the carbon dioxide is dissolved in the skin layer producing a lowering of the glass transition point. The skin layer is then again closely cohered to the surface of the die by increasing the applied pressure on the resin and the die is then cooled to set the moulded product under the holding pressure. Products with excellent transcription and gloss level of surface can be obtained.