When using an injection molding machine, we may encounter the problem of depressions in the molded parts of the injection molding machine i. How to solve the depression of the injection molded parts?2., the injection molding machine mold
1. Injection molding machine
If the nozzle hole is too large, the molten material will flow back and shrink, and the resistance will be too small and the material will shrink. If the clamping force is lacking, the flash will also show shrinkage, so check if there is any problem with the clamping system. If the amount of plasticization is lacking, a machine with a large amount of plasticization should be used to check whether the screw and barrel are worn. How to deal with the depression of injection molded parts?
The design of the part should make the wall thickness even, and ensure the shrinkage difference. The cooling and heating system of the mold must ensure that the temperature of each part is different. The gating system should be unobstructed and the resistance should not be too large. For example, the size of the main runner, runner and gate should be appropriate, the brightness should be sufficient, and the transition zone should be arc transitioned. The temperature should be increased for thin parts to ensure material flow and smoothness, and the mold temperature should be lowered for thick-walled parts. The gate should be opened symmetrically, and should be opened in the thick wall part of the product as much as possible, and the volume of the cold slug well should be increased.3. plastic injection molding machine
Crystalline plastics shrink more fiercely than non-crystalline plastics, so the amount of material should be increased appropriately during processing, or a nucleating agent should be added to the plastic to accelerate crystallization and reduce shrinkage.4.injection molding machine processing
The temperature of the barrel is too high and the volume changes greatly, especially the forehearth temperature. For the plastic with poor mobility, the temperature should be increased appropriately to ensure smoothness. The injection pressure, speed, back pressure is too low, and the injection time is too short, so that the material volume or density is lacking and the contraction pressure, the speed, the back pressure is too large, and the time is too long to form flash and shrink. The feeding amount means that the injection pressure is consumed when the cushion is too large, and the amount of material is insufficient when it is too small.
Regarding the parts that do not require precision, after the injection and holding pressure, the outer layer is basically condensed and hardened, and the sandwich part is still soft and can be ejected from the injection molding machine
as soon as possible, and let it cool slowly in air or hot water , Can make the contraction and depression gentle and not so conspicuous without affecting the application.