Abstract: Improved apparatus for plastic molding devices and more particularly for an improved injection plastic molding machine which uses mold inserts carried by pockets in the machinery where a first platen is provided having a first platen pocket to receive a first mold half to be located in communication with a source of plastic material for example thermoplastic material, a second platen having a second platen pocket adapted to receive a second mold half so that the second mold half can be moved to abutting relation with the first mold half to form a cavity defined by the first and second mold halves into which molten plastic material is injected. A source of cooling fluid can be provided through the first and second platen to the first and second mold halves utilizing seal devices between the first and second platens and the first and second mold halves respectively.