Plastic parts are more and more widely used, from simple tableware, kitchenware to complex mechanical parts, electronic product shells and so on. However, for plastic parts with high precision, such as electronic product shells, attention should be paid to their precision requirements from the beginning of injection moulding manufacturing.
What factors determine the accuracy of plastic parts during injection molding? How can we improve the precision of thin-walled injection moulding parts?
- Closing pressure: In principle, it should be greater than the total pressure of plastic injection into the mold, based on no burr.
- Pressure and speed have a part of the same relationship. The purpose of acting on the die is to make the material enter the die evenly, thoroughly and properly to fill all corners. Too low will shoot short, shrink, too high with hair, too full, viscous mold, burning, vulnerable mold and high internal stress bad phenomenon.
- The speed determines the condition of raw materials in the runner of the die and the finished products. If the raw materials are burred, saturated, burnt, and slow down, short shot, shrinkage, poor combination and easy to break will occur.
- Temperature: Different raw materials, different temperatures, too low melt opacity and lead to uneven color, the internal stress of finished products increased. Because the temperature is too low and the pressure is too high, it may cause the screw to break, too high, the product has hairy edges, and the temperature difference caused by cooling, causing shrinkage. Raw materials will decompose, yellowing, discoloration, easy to fracture. The longer the cooling time, the gas is not easy to discharge.