Maintenance and care of injection molding machine - Closing Control

1.4.2.7 Closing Control Closing is the use of huge mechanical thrust to tighten the mold to withstand the high pressure injection and filling molds of the molten plastic in the injection molding process, so that the mold will have a huge opening force. 
The safety gate is closed and each trip switch gives a signal and the closing action starts immediately. The first is the slow start of the moving plate. After a short distance, the control bar that originally pressed the slow switch is disengaged, and the movable plate moves forward quickly. When it is approaching the end of closing the mold, the lever at the other end of the control lever presses the slow switch again, and at this time, the movable board turns slowly and advances at low pressure. In the process of low-pressure mold clamping, if there is no obstacle between the molds, it can be smoothly closed to press the high-voltage switch. The high-pressure switch is to straighten the machine hinge to complete the mold clamping action. This distance is very short, generally only 0.3 ~ 1.0mm, just turn the high pressure immediately hit the mold closure limit switch, then stop the action, the mold closing process. 
The mold clamping structure of the injection molding machine is fully hydraulic and mechanical linkage. Regardless of the type of structure, the clamping force is finally exerted by the complete extension of the connecting rod. The straightening process of the connecting rod is a process in which the movable plate and the tail plate are stretched, and the process in which the four rods are pulled by force. 
The size of the mold clamping force can be known from the highest value of the instantaneous oil pressure table of the tight mold. If the mold clamping force is large, the maximum value of the oil pressure meter will be high, and vice versa. Smaller injection molding machines do not have mold clamping oil pressure gauges. At this time, it is necessary to judge whether the molds are actually tight according to the straightening conditions of the connecting rods. If an injection molding machine molds the connecting rod to straighten easily when it is closed, or if the “difficult” fails to straighten, or if one pair of connecting rods is not fully straightened, the expansion mold will appear during the injection molding. Flashes or other problems occur.