The application of plastic parts is becoming more and more widespread, from simple tableware and kitchenware to complex mechanical parts, electronic products shells, etc. are used to plastic parts, but for electronic products shells and other plastic parts with high precision requirements, in the injection molding manufacturing from the beginning of the mold manufacturing should pay attention to its precision requirements.
And in the plastic injection molding processing stage, the precision of which factors determines? What can be used to improve the accuracy of thin-walled injection molded parts?
1. Off the mold pressure: in principle, it should be greater than the total pressure of plastic injection into the mold, to avoid getting burrs as a benchmark.
2. Pressure and speed have part of the same relationship with the purpose of the role in the mold is to make the raw materials into the mould can be uniform, thorough, and the right amount full of all corners. Too low will be short shot, shrinkage, too high with a fuzzy head, too complete, sticky mold, scorching, easy to damage the mold and high internal stress and other undesirable phenomena.
3. The speed is to decide the raw material in the mold sprue, and the finished product in the condition, fast with burrs, overfull, scorched, slow will appear short shot, shrinkage, combined with bad easy to break, etc.
4.Temperature is different from raw materials. The temperature varies; too low melt glue impermeable and leads to uneven colour, and the finished product of the internal stress increases. Because the temperature is too low, the pressure increase is too high. It may cause the screw fracture, too high, the product has a burr, and the temperature difference due to cooling causes shrinkage. The raw material will decompose, become yellow, discoloured, and easy to break. The cooling time becomes more prolonged, and the gas is not quickly discharged.