Vertical injection machine using three chambers and correlation injection molding method

A vertical injection machine (200) having a first chamber (210) for supplying liquid metal, a second chamber (220) located lower than the first chamber and a first conduit (215) connecting the first chamber to the second chamber. The first conduit has a shutter rod (217) disposed within and a valve head (218) attached to a lower portion of the shutter rod. The valve head is adapted to seal a lower portion of the first conduit. A metering rod (222) is disposed within the second chamber. The vertical injection machine also includes a vertically oriented third chamber (230) and a second conduit (225) connecting the second chamber to the third chamber. An injection rod (237) is disposed vertically within the third chamber and a injection nozzle (240) is located at an upper portion of the third chamber.