Pre-plasticising, and pressure injection moulding machine unit

摘要

An injection moulding unit, of the pre-plasticising type comprises a screw- (3) plasticiser (5) in its first tubular casing (2), for material introduced via the funnel (4). The injection unit doses the molten resin supplied by the plasticiser, using a second screw (7) in a second casing (6). A change over valve (10) is located in the resin passage running from the plasticiser outlet (20) to the inlet of the injection unit. A storage unit (13) houses a thrust piston (11) in its storage chamber (12), the piston closing down to the resin passage (9p) in one end position. The unit is connected to a point between the change-over valve (10) and the outlet (20) of the plasticiser. Also claimed is the control method for the unit.