Gas Assist Injection Molding
Gas assist injection molding is a process that utilizes an inert gas to create one or more hollow channels within the injection-molded plastic parts. At the end of the filling stage, the gas is injected into the still liquid core of the molding. From there, the gas follows the path of least resistance and replaces the thick molten ejections with gas-filled channels. Next, gas pressure packs the plastic against the mold cavity surface, compensating for volumetric shrinkage until the part solidifies. Finally, the gas is vented to the atmosphere or recycled.
The process is especially ideal for large handles, equipment covers, doors, bezels, cabinets and skins. It significantly reduces material usage while producing a part with superior structure and aesthetics.
Gas assist injection molding has been around for well over 200 hundred years, and many people have had concerns over patent rights and royalty fees. Within the past few years though, some of the original patents have expired . Now, gas assist injection molding is widely practiced. Design engineers and processors alike are discovering that this technology is an attractive option for certain applications and offers many benefits. It is the responsibly of injection molders to ascertain whether their practice or technology is covered by any current patents.
