Plastic injection molding is to add granular or powdery raw materials into the hopper of the injection machine, and the raw materials are heated and melted into a flowing state. Under the push of the thread rod or the piston of the injection machine, they enter the mold cavity through the nozzle and the pouring system of the mold, then be hardened and shaped in the mold cavity. Factors affecting the quality of injection molding: injection pressure, injection time, injection temperature, pressure holding time, gate location, runner design, etc. PE, PP, PS, ABS, PC, PA, POM, PBT and PMMA are suitable for plastic injection molding process.