After the plastic material is heated and plasticized in the injection barrel, the molten plastic flow will be injected into the mold cavity through the sprue and runner system, and finally, take shape after being cooled. This manufacturing process is defined as plastic injection molding.

During the molding process, the plastic pellets will be first delivered into the high-temperature injection barrel through the hopper, where they are heated, melted and plasticized into a sticky molten flow, which will then be injected into a lower temperature closed mold through the injection nozzle at a high speed under the great pushing pressure exerted by the plunger or the screw.

Under the great pressure, the molten plastic will fill the entire cavity and will also be compacted. After that, the plunger or the screw will return after a period of pressure holding. At this point, it is possible to flow back from the cavity into the sprue and runner system.

When the mold opens after cooling and forming, the product will be released from the mold cavity.