Method and apparatus for forming green ceramic arc tubes using pressurized fluid assisted injection molding

The present invention relates to a method for forming a green body of a ceramic arc tube used in metal halide lamps, and more particularly, the present invention relates to a method for forming a green body of a shaped ceramic arc tube for use in a metal halide lamp. A method and apparatus for forming a green ceramic arc tube for a metal halide lamp. A feedstock material comprising ceramic and a binder is prepared and injected into an inner cavity of a mold. The inner cavity of the mold has an inner surface that corresponds to a desired outer shape of a body of the ceramic arc tube. A fluid is injected into the feedstock material to create a cavity in the feedstock material and to force the feedstock material into contact with the inner surface of the mold. The mold is then separated from the formed ceramic green arc tube.