In order to cause any damage or abnormality after the plastic mold is injection molded, we need to carry out certain specifications for the injection molding of the mold, and the main requirements meet the following six conditions:
1. Closed mold pressure: In principle, it should be larger than the total pressure of the plastic injection mold, so as not to use the raw edge as the benchmark.
2, pressure and speed have some of the same relationship acting on the mold. The purpose is to make the raw material into the mold evenly, thoroughly, and the right amount fills all corners. Too low will be short shot, shrinking, too high, hairy, full, sticky Die, charred, vulnerable molds and high internal stresses.
3. Speed: The speed of the speed determines the condition of the raw materials in the mold runner and the finished product. It has a burr, a fullness, a burnt, a slow shot, a shrinkage, and a bad combination.
4, temperature: different raw materials, different temperatures, too low, the color of the solution glue is uneven, the internal stress of the finished product increases. Because the temperature is too low, the supercharged pressure is too high, which may cause the screw to break, too high, the product has burrs, and it is cooled. The temperature difference causes shrinkage. The raw material will decompose, turn yellow, discolor, and easily break. The cooling time becomes longer, the gas is not easily discharged, and there is gas.
5, back pressure: the resistance of the screw retreating during the rotary feeding is called back pressure. Its action makes the raw material more tight in the conveying compression. The air and water of the raw material can be discharged from the screw. The sol does not affect the finished surface. The gas composition. Low bubbles, surface silver. High temperature will overheat, agglomerate, overflow, long cycle, screw does not retreat. At the same time, the application of loosening is very important: when the back pressure is low, some raw materials should be retracted, there are It is not necessary to adjust the back pressure according to various raw materials. When the back pressure is high, be sure to use the loosening and pay attention to whether the distance is not involved in air or no glue.
6, the mold temperature and the length of the cooling time, affecting the finished mold, shrinkage, dimensional tolerances, surface brightness, cycle, etc., should be adjusted according to the actual situation. Another acrylic, PC, such as the thickness of the finished product must have The mold temperature does not produce bubbles and stress.