| 摘要 |
A plastics moulding arrangement comprises a mould tool and a plastics injector (5,7) for injecting molten plastics material under pressure into the tool via an additive introduction means (1) which comprises (a) holding means (3) for receiving a charge of molten plastics material introduced therein by injector 5,7 (b) means (4) for causing the charge of material to flow relative to an additive inlet (18) within means 1 when the charge is not pressurised by the injector, and upon retraction of means (piston 4) means (20) for introducing into the flowing plastics material at a predetermined flow rate via the additive inlet an additive material for changing the appearance and/or physical properties of at least a portion of the moulded plastics material. Rotation of screw 7 causes molten plastics to enter bore 3 via a non-return valve 9 which forces piston 4 outwardly and draws piston 24 of means 1 outwardly whilst drawing in additive into bore 23 via reservoir 21. The nozzle 5 and means 1 are advanced until contacted with mould whereupon piston 24 retracts to cause plastics material in bore 3 to enter nozzle 5 via channel 16 and additive to flour into channel 16 from bore 23 via non-return valve 19 to allow mixing. Subsequent impelling of screw 7 drives mixed material via valve 9 into the mould via interconnected passages 10, 11, 13. A plurality of mould cavities may be used to mould plastics of different compositions. |
