The temperature and pressure changes of plastic injecti […]
The temperature and pressure changes of plastic injection molding have a great influence on the dimensional accuracy of plastic products, and are also affected by various factors such as the time of use and the environment. Therefore, in order to process high-precision products, we must first master the injection molding products. What factors affect size?
1: What factors affect the size of injection molded products?
1) Limited by the mobility of plastic raw materials. Under certain equipment and injection molding process conditions, plastics with good fluidity can form plastic parts of larger size; on the contrary, plastics with low fluidity can form plastic parts of smaller size.
2) The size of injection molded products is also limited by injection molding equipment. The size of injection molded plastic parts is limited by the injection volume, clamping force and template size of the injection machine; the size of compression and injection molded plastic parts is limited by the press machine. The maximum pressure and the maximum size of the press table are limited.
2: What are the factors that cause the dimensional instability of plastic parts?
1) The electrical and hydraulic systems of the injection machine are unstable;
2) The feeding amount is unstable;
3) The plastic particles are uneven and the shrinkage rate is unstable;
4) The injection molding conditions (temperature, pressure, time) change, and the molding cycle is inconsistent;
5) The gate of the injection mold is too small, the size of the multi-cavity feeding port is inconsistent, and the feeding is unbalanced;
6) The precision of the injection mold is poor, the movement of the moving parts is unstable, and the positioning is not accurate.