METHOD AND APPARATUS FOR INJECTION MOLDING CERAMIC VALVES

An apparatus and method for injection molding a unitary ceramic part such as an engine valve contemplates a mold having a die cavity therein shaped like an engine valve. The die cavity is formed with a head portion of the valve at a first portion of the cavity and a stem portion of the valve at a second portion of the cavity. Molding material is injected slowly into the die cavity by an injection molding apparatus connected to the mold. As the molding material is slowly injected into the cavity, the material moves up through the die cavity forcing air out of a vented portion on the mold until the die cavity is filled. A temperature control plate, connected to the mold adjacent the first portion of the die cavity, allows a cooling fluid to circulate therein in order to permit controlled cooling of the part from the head portion of the valve down to the stem portion. After the valve has cooled and solidified it is removed. 5583P