Abstract: A mould tool comprises a primary cavity part (201), a core part (202), a secondary cavity assembly (203) and an actuation ring (204). The primary cavity part (201) is attached to the fixed platen of a moulding machine in use and incorporates an injection gate (211). The core part (202) is attached to the moving platen and has a fixed portion (2021) having outside its preform shaping surfaces (20211) four pivot points (224)—of which two are shown—for the secondary cavity petals (2030), of which there are four. Also the core part incorporates a movable portion (2022), comprised of a preform shaping end plate (20221), a carrier (20222) for the end plate, a pair of movement rods (20223) to which the carrier is attached and which are housed in bores (20224) in the core (202) via linear bearings (20225).
Abstract: A metering device is disclosed for use in a plastics moulding machine having a mould cavity, relatively movable platens and a feeding passage for feeding a plastics melt into the mould cavity. The metering device comprises a heated block interposed between the feeding means and the mould cavity. A cylinder with a moving piston is formed in the block. A first passage in the block connects the cylinder to the feeding means and a second passage connects the cylinder to the mould cavity. Valves in the passages enable the cylinder to be filled by the feeding passage without the plastic melt entering the mould cavity and subsequently enable the desired dose of plastics melt, when ejected from the cylinder by the piston, to flow from the cylinder to the mould cavity without being returned to the feeding passage.
Abstract: A cup of plastics material incorporating foaming agents has thin wall portions, namely a base (101), a lower side wall (102) and an upper side wall (103). These portions have their wall thickness determined by mold part gap. The cup also has thick wall portions, namely the corner (104), the band (105) and the rim (106), in which foaming occurs after mold opening so that the wall thickness is increased beyond that provided by the mold.
Abstract: A method of forming an article via injection of plastics material into a mould consisting in the steps of: providing a mould tool (11) defining in its closed state a mould cavity, the mould tool being adapted to be partially expandable from an injection volume (FIG. 2) for receiving a load of plastics material to a final, larger volume (FIG.
Abstract: The cylinder head (8) of an injection molding machine has a transverse bore (20), in which is threadedly engaged a gas introduction device (21) connected to a gas bottle (22), having a pressure regulator (23). The device has a body (24) which carries a valve poppet (25) in a complementarily shaped bore (26) opening to the passage through the cylinder head. A spring (27) normally closes the poppet valve. A control valve (28), under control of the system (7) is provided upstream of the poppet valve. Gas is introduced into the injection chamber of the machine after suck back and before screw rotate for feeding plastics material to the injection chamber. On injection, the material is injected with the gas added to it.
Abstract: A cup of plastics material incorporating foaming agent has thin wall portions, namely a base 101, a lower side wall 102 and an upper side wall 103. These portions have their wall thickness determined by mould part gap. The cup also has thick wall portions, namely the corner 104, the band 105 and the rim 106, in which foaming occurs after mould opening so that the wall thickness is increased beyond that provided by the mould.