Injection molding process and apparatus
AssigneeNational Can Corporation
InventorDonald G. Sauer
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Abstract
There is disclosed a gating assembly provided with at least two orifices of different diameters and associated with an injection molding assembly. In an initial stage of extruding the plastic material into a mold cavity, the orifice of larger diameter is utilized to provide the fluid communication between the extruder nozzle and mold cavity whereas the orifice of smaller diameter is utilized in the final stages of injection to insure thorough packing of the plastic material in the injection mold.
Claims4
In an injection molding machine having an assembly adapted to inject a plastic fluid molding material from an extrusion nozzle into an article forming cavity of said injection molding machine, the improvement comprising:
- a gating means provided with first and second orifices, said first orifice having a diameter larger than said second orifice, said gating means being disposed between said extrusion nozzle and said article forming cavity;
- and
- motive means connected to said gating means for moving said gating means from a position wherein said first orifice is disposed between said extrusion nozzle and said article forming cavity to a second position wherein said second orifice is disposed between said extrusion nozzle and said article forming cavity during introduction of said fluid molding material through said orifices into said article forming cavity to thereby ensure thorough packing of said plastic material.
Dependencies are inferred from the claim text.