Nitrogen is widely used in the plastics industry. Injection molding, film extrusion, and gas assist injection molding all use nitrogen because of its inertness and dryness. On site nitrogen is an ideal choice, as nitrogen can be generated on demand without relying on deliveries from a third party supplier.
In injection molding, moisture and oxygen can cause issues with the final product including defects and blemishes. Using dry nitrogen generated from a Parker on site nitrogen generator eliminates these complications.
Gas assist injection molding (GIAM) involves a multi-step molding process. It is a way to make thick plastic parts without issues created from excess shrinkage of the part. It is a type of injection molding that uses an inert gas to create a very dense and strong plastic part that uses nitrogen to pack out the part and compensate for shrinkage. First the polymer is injected into a mold though not all filled. Nitrogen under high pressure is injected into the polymer, pushing it into areas of the mold that are not yet filled. The nitrogen pressure is maintained during the cooling phase of the molding process, and gas pressure is released and the part is ejected.
Film extrusion is achieved by extruding a molten thermoplastic using a screw through a die. Afterward, it is inflated to many times its initial diameter forming a thin tubular film. Screw carbonization and frequent die cleaning, caused by oxygen in the feed throat hopper, are issues with blown film extrusion that can be improved or eliminated by using a nitrogen purge
To learn more about in-house nitrogen generation for the above applications, please call (800) 343-4048 or visit our product page for nitrogen generators.
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