injection of the injection mixture 46 at the beginning of the molding process the hydraulic piston 16 is actuated to force the piston ram 32 toward the first plate 20 the platen 30 disburses the force of the piston ram 32 to the mold carriage 26 and the second mold section 38 the second mold section 38 is moved into engagement with the first mold section 36 to form a mold cavity 40 the injection mixture 46 may include a blowing agent mixed with a plastic injection material as described in u s pat no 6 139 934 the disclosure of which is incorporated herein by this reference the injection mixture 46 is heated to an injection temperature and injected into the molding cavities 40 the injection temperature is hot enough to plasticize the injection mixture 46 and hot enough that the blowing agent will decompose or be activated unless the injection mixture 46 is pressurized in the preferred embodiment the injection temperature is approximately 400 degrees fahrenheit before the injection mixture 46 is injected into the mold cavity 40 it is first plasticized to provide a flowable material which eventually hardens into a finished plastic article the following parameters affect the plasticization process the type of raw plastic material to be plasticized throat temperature the temperature of injection assembly heating zones the size length and type of screw 60 the rate at which the screw 60 is turned and the rate at which the screw 60 is allowed to move back like the plasticization process the injection process is also controlled by the computer control program the.