Patent ID: 6592804
Filing Date: 2003-07-15
Classification: B28B,H01J

Abstract:
A method for forming a green ceramic arc tube for a metal halide lamp, comprising:a) preparing a feedstock material comprising ceramic and a binder; b) injecting said feedstock material into an inner cavity of a mold having an inner surface corresponding to a desired outer shape of a body of said ceramic arc tube, wherein an outer diameter of an arc discharging portion is larger than that of end portions of the arc tube which hold discharging electrodes; c) injecting a fluid into said feedstock material to create a cavity in said feedstock material and force said feedstock material into contact with said inner surface of said mold, wherein a ratio of said viscosity of said feedstock material to said viscosity of said fluid is at least 100 to 1; and d) separating said mold from the ceramic green arc tube.