Compression molding machine for organic thermoplastic materials

Abstract

This invention provides a high output machine for effecting the production of organic thermoplastic articles by the compression molding technique. A plurality of molding members having open top molding cavities are movable around a horizontal closed loop path. A plurality of horizontally moving plungers are provided which are respectively co-operable with the molding members in a portion of their path to close the open top of the molding cavities. Successive gobs of heated organic thermoplastic material are deposited in the open top molding cavities at a point prior to the molding members moving into vertical alignment with the plungers. A relative vertical displacement between the plunger and the molding members is then effected to bring each plunger into engagement with the respective molding member and effect the compression molding of the inserted gob to conform to the molding cavity. After formation of the molded article and appropriate time for cooling, the molding members and plungers are relatively vertically displaced to permit the molded thermoplastic article to be removed from the molding cavity. In accordance with a specific embodiment of this invention, the molded article may comprise the end wall of a can and successive can side walls or bodies are respectively disposed in surrounding relationship to the plungers and carried into the compression molding area with the end portions of such bodies entering the molding cavity so that the compression molded end wall is formed around and united to the side wall in the compression molding operation.