apparatus for injection moulding a plastic material to be from a source of such material in cavite for injection mould mould in response to a moving source.

摘要

An apparatus and method for injection molding or impact molding from a source of plasticized material at a pressure independent of the source pressure. The apparatus includes a piston freely floating in an accumulation chamber to which material is supplied at source pressure, as by an extruder, and a valving nozzle through which the piston expresses material at a different pressure. The actuating force is generated by relative source-mold closing movement and is transmitted by the mold-contacting nozzle to the piston to sequentially establish mold-accumulator chamber communication, isolate the accumulation chamber from the material source, and inject material from the accumulation chamber through the nozzle into the mold at the independent pressure. Upon relative source-mold opening movement, the mold-accumulator chamber communication is interrupted and the accumulation chamber is replenished with material from the source at the source pressure.