A good set of plastic molds is caused by many factors, but each factor may affect the quality of the mold, material selection, processing equipment, processing environment and processing technology. Here we mainly start from the processing technology of plastic molds. Analysis to see what factors affect the quality of plastic molds.
The first point is the injection pressure of the plastic mold, which is supplied by the hydraulic system of the injection molding system. The pressure of the hydraulic cylinder is transmitted to the plastic solution through the screw of the injection molding machine. Under the pressure, the plastic solution passes through the nozzle of the injection molding machine to enter the vertical flow channel, the main flow channel and the branch flow path of the mold, and passes through the gate. Then enter the mold cavity, this process is the process of accommodation, or can be called the filling process. The pressure exists to overcome the resistance during the flow of the solution, or conversely, the resistance existing in the flow process needs to be offset by the pressure of the injection molding machine to ensure the smooth filling process.
The second factor is the temperature of the injection molding, which is an important factor affecting the injection pressure. The temperature of the injection must be controlled within a certain range. If the temperature is too low, the melt plasticization is poor, which will affect the quality of the molded part and increase the difficulty of the process; if the temperature is too high, the raw material will be easily decomposed. In the actual injection molding process, the injection temperature tends to be higher than the barrel temperature. The higher the value is related to the injection rate and the material properties. It can reach up to 30 °C. This is caused by the high heat generated by the shearing of the melt as it passes through the injection port.
The last point is the injection time of the plastic mold, which is the time required for the plastic solution to fill the cavity. It does not include the auxiliary time such as opening and closing of the mold. Although the injection molding time is short and the influence on the forming cycle is small, the adjustment of the injection time has a great effect on the gate, runner and cavity pressure control. Proper injection time helps the ideal filling of the solution, and it is very important to improve the surface quality of the product and reduce the dimensional tolerance.
The above three points are the key factors we need to master in the manufacture of Kunshan plastic molds. Of course, the first thing we can't ignore is the selection of materials. After all, there is no good plastic mold without good steel.