Plastic injection moulding is by far the most common way to produce large volumes of finished plastic parts for every kind of commercial and industrial use. Molten resin is injected under high pressure into the cavity of a metal die and then rapidly cooled, forming a solid shape. A single cycle to make a finished part may take anywhere from a few seconds to minutes depending on part complexity and size.
Plastic injection moulding is the preferred process for manufacturing plastic parts. Injection moulds are used to create many things such as electronic housings, containers, bottle caps, automotive interiors, pocket combs, and most other plastic products available today. Plastic injection moulds are ideal for producing high volumes of plastic parts, due to the ability of making multi-cavity injection moulded parts, where multiple parts are made with one cycle. Some advantages of injection moulding are high tolerances, repeatability, a wide range of material selection, low labor cost, minimal scrap losses, and little need to finish parts after moulding. Some disadvantages of this process include an expensive tooling investment and the need to prototype, as some custom complex parts may encounter problems during the injection moulding process such as warp or surface defects. Therefore, injection moulded parts must be designed with careful moulding consideration.