INJECTION MOLDING: Multi-Shot In-Mold Assembly Swaps Out TPE for LSR

Special cold-sprue bushing and third LSR-specific injection unit create finished, sealed automotive duct in 55 seconds.

Building off a concept which had previous iterations displayed at NPE2012 and NPE2015, French mold maker Georges Pernoud (U.S. office in Detroit) has added over molding of an LSR gasket on its Multitube technology in lieu of a TPE. Georges Pernoud says the addition of LSR was in response to a specific request from the automotive market. The manifold at the show will be molded from 30% glass-filled nylon. 

This newly developed application will be presented during K2016 at the booth of French injection molding machine maker Billion SAS (Hall 15, Stand B24). The Multitube technology utilizes a specialized multi-material tool, which includes over molding of four threaded inserts. At K2016, the demo part shown will be an air-intake manifold, but the technology can also be applied to air ducts, turbo ducts, filter assemblies, and water manifolds and tubes.

The company says Multitube’s benefits include productivity and cost savings generated by integrating processes into the mold and eliminating post-mold secondary operations, like welding. At the show, a 200-ton multi-shot all-electric plastic injection molding machine from Billion will be used, just as at NPE2015. However, at K2016, Milacron’s Mold Masters will provide the third, auxiliary injection unit. Specifically designed for LSR and all-electric, the third injection unit will sit on top of the Georges Pernoud tool. The process will run an average cycle time of 55 seconds for a finished part. To manage the LSR in an otherwise thermoplastic setup, Georges Pernoud has designed and produced a specialized cold-sprue bushing. 

Apart from nylon, Georges Pernoud has run experiments with glass-filled polypropylene, PPS, and PPA.