Injection molding is the largest plastics industry sector, and continues to outperform the overall industrial average. It is a fast process that is used to produce a large number of identical parts, ranging from precision engineering pieces to disposable consumer goods.
The process can make either thermoplastic or thermoset parts. Typically material is fed into a heated barrel, and forced into a mold cavity by a reciprocating screw or a ram injector. The injection molded part cools and hardens to the configuration of the mold.
The segment has seen a number of innovations to help reduce the rate of faulty production. As a result, injection molded technology has gained share in the mass production of complicated plastic shapes.
Parts are generally designed by a designer or engineer. Molds are produced by a mold maker. This process can be done in-house or it can be outsourced.
The process is done under high pressure, which can vary depending on the material being used. Tools generally are made from steel or aluminum. Tool steel can be hardened and plated. Aluminum alloys are used for higher cutting and hand polishing speeds.
The tool can be used to manufacture one consistent part in a repeating process or incorporate multi-cavities, such as molds used for plastic caps and closures. This allows the process to make many parts with a single injection.
There are variations of the injection molding process. These include multi-shot; insert molding; structural foam molding; and assisted molding. There are a number of technologies that are impacting the injection molding segment today, including 3-D printing for prototyping, Internet of Things (also known as Industry 4.0), and automation. These can help molders reduce the time needed to bring a part to market, improve cycle times and productivity.
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