When nitrogen is introduced into the injection molding equation, it improves not only the strength of the product but also the quality. That’s because as liquid plastic is being injected into the mould, nitrogen is then introduced. This introduction of nitrogen pushes the plastic into every area of the mould producing a better product. Oxygen leaves small bubbles or pockets which can make the product brittle.
Gas assist injection molding also allows you to reduce the wall thickness of the product and you end up with a product free of cracks or imperfections. By ending up with a superior product, you save money on raw materials as well as customer returns for defective inventory, not to mention reducing labor costs.
Blown Film Extrusion
Plastic bags, plastic wrap, shrink wrap are examples of plastics made from Blown Film Extrusion. The blown film extrusion process consists of an extruded tube of molten thermoplastic that is inflated to several times its initial diameter, forming a very thin tubular product which can be used or slit which forms a flat film. Nitrogen is often used for oxygen sensitive materials to prevent discoloration.