Injection moulding of thin articles, esp. compact discs

摘要

The process cycle in an injection moulding machine comprises a speed controlled forward movement of the screw (2) to fill the mould (4) and a pressure controlled holding of the pressure when the mould is full. The end position (Xs) of the forward motion of the screw is controlled by the quantity of material required, the mould pressure (Pc) and the degree of mould opening (So). The screw is held in this position for a pre-determined period (ts) while pressure is applied to the mould based on the mould pressure (Pc).