Parameters Of Injection Pressure

Injection pressure is provided by the hydraulic system of the injection molding system. The pressure of the hydraulic cylinder is transmitted to the plastic melt through the injection molding machine screw, and the plastic melt is driven by the pressure, and the nozzle of the injection molding machine enters the vertical flow channel of the mold (for some molds, it is also the mainstream channel), the mainstream channel, the shunt channel, and enters the mold cavity through the gate. This process is the injection molding process, or the filling process. The existence of pressure is to overcome the resistance in the melt flow process, or conversely, the resistance in the flow process needs to be offset by the pressure of the injection molding machine to ensure the smooth filling process.
During the injection molding process, the pressure at the nozzle of the injection molding machine is the highest to overcome the flow resistance throughout the melt. Subsequently, the pressure is gradually reduced along the flow length to the most front wave front of the melt. If the exhaust inside the mold cavity is good, the final pressure at the front of the melt is atmospheric pressure.
There are many factors affecting the melt filling pressure, which can be summarized into three categories: (1) material factors, such as the type of plastic, viscosity, etc.; (2) Structural factors, such as the type, number and location of the pouring system, the shape of the mold cavity and the thickness of the product; (3) Molding process elements.