7 The Basics of an Injection Molding Machine (See also IMT, which contains much basic information on injection molding, molding machines, and molds.) The injection molding machine (Fig 3.1) provides         A safe support for the mold The opening and closing motion of the mold halves The clamping force to keep the mold closed while injecting The melted (plasticized) plastic to be injected The injection force to ®ll the mold cavity space The ejection force All necessary sequencing and temperature controls Any additional functions as may be required Molding machines come in many different sizes, from small machines with a few kilonewtons (tons) of clamping force, to giant machines with 80,000 kN Figure 3.1 Schematic of an injection molding machine (top view) 8 The Basics of an Injection Molding Machine (8800 US tons), for very large products All machines can be equipped with a choice of standard injection units, suitable for the mold size and output required At this point, we will not go further into the functions of the molding machine When discussing the injection mold, we will explain, when required, how the functions of the machine and the mold are interrelated