How to improve the precision of thin-wall injection molding?
The application range of plastic parts is becoming more and more extensive, from simple tableware and kitchen utensils to complex mechanical parts and electronic product shells. However, for plastic parts with high precision requirements such as electronic product shells, the precision requirements should be paid attention to from the beginning of mold manufacturing during injection molding.
What factors determine the precision of plastic parts during injection molding? How can we improve the precision of thin-wall injection molded parts?
1. Mold pressure: In principle, it should be greater than the total pressure of plastic injection into the mold, with no burrs as the benchmark.
2. Pressure and speed have a similar relationship. The purpose of acting on the mold is to make the raw materials enter the mold evenly, thoroughly, and properly fill every corner. Too low will cause short shot, shrinkage, too high will cause burrs, oversaturation, mold sticking, burning, easy to damage the mold and high internal stress.
3. The speed determines the condition of the raw materials in the mold runner and the finished product. If it is too fast, there will be burrs, overfilling, and burning. If it is too slow, there will be short shots, shrinkage, poor bonding, and easy breakage.
4. The temperature of the raw materials is different, and the temperature is different. If it is too low, the melt will not penetrate, resulting in uneven color and increased internal stress of the finished product. If the temperature is too low and the pressure is too high, the screw may break. If it is too high, the product will have burrs, and the temperature difference caused by cooling will cause shrinkage. The raw materials will decompose, turn yellow, change color, and break easily. If the cooling time is longer, the gas will not be easy to discharge.