Gas-assist injection molding is a process that utilizes an inert gas (normally nitrogen) to create one or more hollow channels within an injection molded plastic part. At the end of the filling stage, the gas (N2) is injected into the still liquid core of the molding. From there, the gas follows the path of the least resistance and replaces the thick molten sections 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.
Gas-assist injection molding has been around for well over two decades and many people have had concerns over patent, rights and […]