Injection control mold opening and Clamping
It is still very important to understand the operation of injection molding machine molds. Next, I will explain to you the opening and Clamping of molds.
Mold opening control:
When the molten plastic is injected into the mold cavity and after cooling is completed, the product is taken out with the mold opening action. The mold opening process is also divided into three stages. The first stage slowly opens the mold to prevent the parts from tearing in the mold cavity.
Rapid mold opening in the second stage to shorten the mold opening time. In the third stage, the mold is opened slowly to reduce the impact and vibration caused by the inertia of the mold opening.
Injection control mold
The mold clamping is to close the mold with a huge mechanical thrust to resist the high-pressure injection of molten plastic during the injection molding process and fill the mold to cause the huge opening force of the mold.
The safety door is closed, each travel switch gives a signal, and the mold clamping action starts immediately. The first is that the moving template is started at a slow speed. After advancing a short distance, the control lever pressing block that originally pressed the slow switch is disengaged, and the movable plate turns to quickly advance. When advancing to close to the end of the mold clamping, the pressure rod at the other end of the control lever presses the slow switch again, at this time the movable plate rotates again at a slow speed and advances at a low pressure.
During the low-pressure mold clamping process, if there are no obstacles between the molds, they can be smoothly closed to press the high-pressure switch, and the high pressure is turned to straighten the hinge of the machine to complete the mold-closing action. This distance is extremely short, generally only 0.3 ~ 1.0mm. As soon as the high pressure is turned, the mold closing limit switch is touched. At this time, the action stops and the mold closing process ends.
The mold clamping structure of the injection molding machine has a full hydraulic type and a mechanical link type. No matter what kind of structure, in the end, the connecting rod is fully straightened to implement the clamping force. The straightening process of the connecting rod is the process of the expansion of the movable plate and the tail plate, and also the process of the four tension rods being stretched under force.
The magnitude of the clamping force can be known from the moment when the hydraulic pressure gauge rises at the moment of closing the mold. If the clamping force is large, the highest value of the hydraulic pressure gauge is high, and vice versa. Smaller injection molding machines do not have a clamping oil pressure gauge. At this time, it is necessary to judge whether the mold is really tight according to the straightening of the connecting rod.
If the connecting rod is easily straightened when a certain injection molding machine is closed, or “almost” failed to straighten, or one of the several connecting rods is not fully straightened, the mold will expand during injection, and the workpiece There will be flash or other problems.
Injection control mold