The rod will bend, break and so on
The quality of the self-made top rod is better, but the processing cost is higher, now the mold structure is generally used standard parts, the quality is at the normal level. If the gap between the top rod and the guide hole is too large, the leakage will occur. But if the gap is too small, the injection molding mold temperatures will rise, can lead to a plunger, expansion and jammed, sometimes even plunger is out after a certain distance is fixed and deformation, lead to the next mold-shut, higher than the push rod can't reset crashed cavity directly.
If this problem occurs, the plunger should be reworked, and the die structure will be maintained at the front end of the top bar with a 10-15mm coordination segment, with the middle part grinding 0.2mm. All the top poles must be strictly checked for the clearance after assembly, generally within 0.05 to 0.08 mm, to ensure that the entire ejection mechanism can move back and forth.
Poor cooling or water leakage
The cooling effect of mould directly affects the quality and production efficiency of the products. If the cooling is bad, the products shrink large, or the shrinkage is uneven and the deformation of the warped surface and other defects; On the other hand, the whole or part of the die is overheating, so that the mold can not be formed normally and the die will be damaged.
The cooling system design, processing, the shape of the product, don't cry because it is complicated or difficult to machining mould structure and eliminate the system, especially in large and medium-sized mold, must fully consider the cooling problem.