Abstract: A blow molding method including a clamp for clamping two molds in back-to-back relationship, the clamp having first and second movable, inner platens supporting interior sections of two molds; first and second movable outer platens supporting exterior mold sections facing the interior sections; a positioner to move the inner and outer platens between opened and closed positions; an extrusion means to extrude parisons between mold sections, injectors to inject air into the interior of the parisons; and a platen retainer to resiliently position the inner platens between the outer platens to equalize pressure in the two molds.

Abstract: First and second hollow bodies are blow molded in back-to-back alignment in a blow molding clamp having a central platen with first and second opposed, outwardly facing, mold supporting surfaces; a first movable platen with a mold supporting surface facing the first mold supporting surface of the central platen; and a second movable platen with a mold supporting surface facing the second mold supporting surface of the central platen; by continually extruding first and second parisons; positioning the first parison between the central platen and the first movable platen and the second parison between the central platen and the second movable platen; moving the movable platens to their closed position around the parisons; and simultaneously injecting a gas into the interior of the first and second parisons between each central platen and opposed first and second movable platens while the platens are in the closed position.

Abstract: A blow molding apparatus including a clamp for clamping two molds in back-to-back relationship, the clamp having first and second movable, inner platens supporting interior sections of two molds; first and second movable outer platens supporting exterior mold sections facing the interior sections; a positioner to move the inner and outer platens between opened and closed positions; an extrusion means to extrude parisons between mold sections, injectors to inject air into the interior of the parisons; and a platen retainer to resiliently position the inner platens between the outer platens to equalize pressure in the two molds.

Abstract: A blow molding apparatus including a clamp for clamping two molds in fixed, back-to-back relationship, the clamp having a central platen supporting interior sections of two molds in a fixed, back-to-back relationship, and first and second movable platens supporting exterior mold sections facing the interior sections. The apparatus also includes a clamp positioner to move the movable platens between opened and closed positions, an extruder to extrude parisons between mold sections, injectors to inject air into the interior of the parisons, and a central platen retainer to resiliently position the central platen between the movable platens.