Apparatus for runnerless injection compression molding of thermosetting materials

摘要

The apparatus of the present invention includes a stationary assembly and a movable assembly. The stationary assembly is comprised of a stationary platen which has a heat plate mounted thereon, a temperature-controlled sprue bushing mounted in the heat plate and a plurality of mold faces positioned on the heat plate surrounding the periphery of the sprue bushing. The movable assembly is comprised of a movable platen which has a heat plate mounted thereon and a plurality of mold faces, corresponding to, and adapted to be aligned with, the mold faces on the stationary assembly. Means are provided to move the movable assembly into close proximity with the stationary assembly to form partially open mold cavities. Means are provided to feed a supply of thermosetting molding material through the sprue bushing into a manifold area and into the partially open mold cavities. Means are provided to completely close the mold cavities and place the apparatus in a compression stage. In the compression stage, the manifold area is eliminated by closure of the stationary and movable assemblies. Means are also provided for the subsequent retraction of the movable assembly to allow removal of the molded article and access to the mold area.