9. Compound Heating Unit (Barrel)
A hollow steel barrel houses either the screw or the plunger and is capable of being heated externally with electric band heaters or being jacketed for heating with hot water.
10.Compound Delivery Unit
The SI presses utilize a high-torque, low-speed hydraulic screw motor to actuate an extruder screw that serves to auger the compound out of the material hopper along its flutes, picking up sufficient heat to be capable of flowing under pressure into the mold. At the proper time, the screw then becomes a piston or plunger forcing the heated compound into the mold.
The PI relies upon the plunger to move backward within the barrel until the end of the plunger has gone beyond the material hopper opening, thus releasing a measured amount of cold material from the hopper into the barrel in front of the plunger. The plunger is then actuated forward hydraulically, forcing the heated compound at the front of the barrel into the mold.
11.Molded Part Ejection Unit
The ejector or KO unit can be either mechanical or hydraulic serving to move the KO bar within the mold at the end of the molding cycle.