Plastic injection moulding is the process of producing parts made of thermoplastic or thermoset plastics. Injection molding is the heating and melting of plastic (usually pellets) in the barrel of an injection molding machine when it is in a flowing state. Under the pressure of the plunger or screw, the molten plastic is compressed and moved forward, and then injected into the lower temperature closed mold through the nozzle at the front end of the barrel at a rapid speed. After a certain period of cooling and setting, the mold is opened and the product is obtained. . This molding method is an intermittent operation process. It consists of two main parts, an injection device and a clamping device.
The mold in the injection molding machine can be fixed in a horizontal or vertical position. Most machines are horizontal, but vertical machines are used for some special applications. This process is similar to casting. The material is injected into a heated barrel, mixed (melted from a solid to a viscous liquid) and squeezed into the mold. The material can be cooled and solidified into the shape of the mold in a mold (cavity).
The product design is usually done by an industrial designer or engineer. The mold for injection molding is made by the mold manufacturer (or tool (mold) manufacturer), usually made of metal such as steel or aluminum, and the desired part. The shape features are formed by precision machined cavities. Injection molding is widely used to manufacture a wide range of components (most plastic products), from the smallest part of the car to the body panel of the car.