Which process parameter adjustments can improve the dimensional accuracy of injection molded parts

When producing important injection molded parts with precise size requirements, the allowable fluctuation range of each part's size is very small, even requiring only one or two threads of fluctuation.
In the production process, the main factor that usually affects the dimensional accuracy of injection molded parts is the shrinkage rate of the injection molded parts. The larger the shrinkage rate, the worse the accuracy. Therefore, due to the high shrinkage rate of PP and POM injection molded parts, their injection molded parts usually have poor accuracy, which is why. The shrinkage rate of other materials is usually not very small, so the dimensional accuracy of injection molded parts is not very high under general conventional injection molding conditions.
In fact, adjusting the machine can reduce the shrinkage rate of injection molded parts, thereby achieving the goal of improving the dimensional accuracy of injection molded parts. We only need to greatly increase the time and pressure for injection molding or pressure holding to reduce the shrinkage of the injection molded parts, significantly reduce the shrinkage rate, and naturally improve the dimensional accuracy.
Due to the quality limitations of injection molding machines, the injection pressure should generally not be adjusted too high, otherwise a large number of batches will be generated. Therefore, on commonly used ordinary injection molding machines, the main goal is to improve the dimensional accuracy of injection molded parts by increasing the injection or holding time.
In order to ensure the dimensional accuracy of injection molded parts, the accuracy of the mold is the first condition that needs to be guaranteed, and it is more important to choose a stable and reliable (with little parameter fluctuation) injection molding machine with sufficient pressure for production.
Some high-precision injection molding machines developed in modern times are actually high-pressure injection molding machines with stable performance and extremely high parameter accuracy. According to the introduction, the shrinkage rate of its injection molded parts can be almost 0, which means that the size of the parts injected each time is almost as long as the size of the mold cavity, with a fluctuation range of only about a trace, and the accuracy can be described as extremely high.