Abstract: A two-shot molding system with four independent molding positions at ninety degree intervals allow injection of the first shot, injection of the second shot, cooling, and ejection of the product to occur simultaneously while the mold is closed. Thus, the invention decreases cycle time, increases throughput, and allows for adequate cooling time without delaying injection and ejection.

Abstract: A grip cap for a container has a thermoplastic shell in an inverted cup shape with a top wall and a skirt bounded by a lower rim. An elastomeric layer is integrally molded to the cap shell along the outer surface of the top wall and the skirt as well as along the underside of the lower rim. This layer defines multiple spaced apart and raised vertical ribs joined by a pad at the top wall and a gasket extending along the lower rim. The ribs and the pad provide a cushion and the gasket can seal against a shoulder of the container when tightened. Also disclosed is a two-shot method of molding such a grip cap, including integral resilient material at the outer surfaces and the underside of the cap shell rim.

Abstract: A two-shot molding system with four independent molding positions at ninety degree intervals allow injection of the first shot, injection of the second shot, cooling, and ejection of the product to occur simultaneously while the mold is closed. Thus, the invention decreases cycle time, increases throughput, and allows for adequate cooling time without delaying injection and ejection.

Abstract: A method of sandwich molding employs independent runners for each of the first and second thermoplastic materials simplifying the construction of the mold and runner passages, facilitating use of hot runner systems and the like, and simplifying the balancing of flow in multiple cavity molds.

Abstract: An in-machine assembly technique uses revolving mold sections that rotate perpendicularly to the clamping axis of the injection-molding machine to increase usable mold area and to provide improved access to molded parts before and after assembly.

Abstract: A multi-material runner gate system allows effective de-gating of elastomeric materials that would otherwise stretch and/or flex reducing de-gating forces at the gate upon separation of the molds.

Abstract: A method of sandwich molding, in which a first thermoplastic material is injected into a mold cavity followed by the injection of a second thermoplastic material expanding within the first thermoplastic material, eliminates the need for heated runner systems communicating from the injection nozzle of the injection molding machine to the mold cavity by employing a cold runner having sufficiently slow solidification time to allow subsequent injections from two injection sources. The backflow into the inactive branch is prevented by maintaining the injection nozzle against the mold until molding is complete.

Abstract: An in-machine assembly technique uses revolving mold sections that rotate perpendicularly to the clamping axis of the injection-molding machine to increase usable mold area and to provide improved access to molded parts before and after assembly.

Abstract: A method of sandwich molding, in which a first thermoplastic material is injected into a mold cavity followed by the injection of a second thermoplastic material expanding within the first thermoplastic material, eliminates the need for heated runner systems communicating from the injection nozzle of the injection molding machine to the mold cavity by employing a cold runner having sufficiently slow solidification time to allow subsequent injections from two injection sources. The backflow into the inactive branch is prevented by maintaining the injection nozzle against the mold until molding is complete.

Abstract: A multi-material runner gate system allows effective de-gating of elastomeric materials that would otherwise stretch and/or flex reducing de-gating forces at the gate upon separation of the molds.