Plastic Injection Molding is the process of producing parts made of thermoplastic or thermoset plastic. Injection molding is to heat and melt the plastic in the barrel of the injection molding machine when it is in a flowing state. Under the pressure of the plunger or the 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. 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 machine can be fixed in a horizontal or vertical position.
Most machines are horizontal, but vertical machines are used for special applications. This process is similar to casting. The material is injected into a heated barrel, mixed (melted from solid to a viscous liquid) and squeezed into the mold.