The injection molding process creates products by injecting a heated liquid into a mold and allowing it to solidify forming that shape. The most common materials utilized in this manufacturing process are plastic, glass, and metal. This manufacturing method is the most common form of mass production. Some examples are buttons, car panels, and toy soldiers. Injection refers to the corkscrew style injector that presses the heated liquefied material into the mold. The material is allowed to cool and harden in the mold. The finished product is then removed and ready for use. The molded material is typically a polymer resin such as thermoplastic, thermosets, and elastomers. There are five specific injection molding processes listed and defined below.
Air Injection Molding: Gas is injected with the liquid material to provide a specific characteristic.
Insert Injection Molding: This process allows plastic material to flow around metal placed inside the mold creating a single part.
Outsert Injection Molding: This process creates a metal covering around molded plastic parts.
Push-Pull Injection Molding: While the material is injected at one end the other is being stretched creating a long thin product.
Sandwich Injection Molding: Two similar polymers are injected sequentially forming reinforcing layers.