Injection molding basic principles are fairly simple, but the actual process can be quite complex when it comes to maintaining part consistency. The process involves the injection of melted plastic into a mold, which is made of steel. The mold itself has cavities that will form the parts; once injected, the molten plastic fills the cavities and the rest of the mold. Once cooled, the parts are ejected by pins.
Thanks to its excellent versatility, injection molding can be used to create everything from large automotive parts to small, intricate parts used in surgical equipment. Injection molding also allows for a high level of customization, as various plastic resins and additives can be used, allowing designers and engineers to create unique parts to meet highly complex or unusual application needs. And there are some enhancements and techniques available — such as an array of resin and finish options — for manufacturers looking to create even more specialized parts.
Though it can be expensive to initially make the molds themselves, once built, the production costs become quite low. In fact, injection molding is best-suited for the creation of very high volumes of precise parts; once production begins the cost per part drops significantly, making the process very economical for high-volume runs.
Plastic injection molding is a highly reliable solution for producing large numbers of precise, consistent components. It’s also more efficient and cost-effective than other molding styles, in that it produces much less waste. As a result, injection molding is most often used for the manufacture of high-quality parts in high volumes.
Of the various molding processes available, injection molding is considered to be the most versatile, as it can be used to create a variety of parts, ranging in both size and shape. Presses also come in different sizes, based on the pressure they exert and their tonnage.