Product burr (flying edge) is a common injection problem, but also very easy to injection problem.
The most important part of the flying edge is the processing of the classification surface, that is, between the moving mode and the static mold, the sliding matching part of the slider, the coordination gap of the insert, the top rod hole seam and other places into the molten material, forming excess flying edge burrs on the fingertips.
Such a flying edge plays a decisive role in forming. If not treated, it is easy to further increase the flying edge burr, resulting in the mold classification facing the face of the depression, leading to the vicious circle of further increase of the brush. Therefore, if we find the inspection, we should repair the mold as soon as possible.
The main and most common reasons for producing burrs are as follows:
1. The partial research and fitting of the mold classification surface is not tight
Whether the fitting of the surface is tight can directly lead to the presence of the product; this depends on the technique of the mold fitter. Mold research is a fine work, test the mold fitter master patience, technology. This is also one of the most direct reasons for the take-off side of the product, so when we find that the research and distribution of the mold is not in place, the solution is to re-study and match the mold machine.
2. The locking structure of the injection molding machine machine
If our mold itself is research with very precise, but using the elbow rod type locking mechanism injection machine molding, often due to poor mold parallel or locking device adjustment, such as the left and right lock imbalance phenomenon, the left and right sides only-edge locked, the other-edge not close, must adjust the rod (two or four root cutting) to balance exhibition.
3. Insufficient mode locking force
Compared with the projection area of the molding parts, if the mold locking force is small, there will be a gap between the dynamic and static modes due to the injection pressure, which is bound to appear flying side burrs. Especially when the side gate is placed on the hole near the center of the piece, because this forming gate needs large injection pressure, it is easy to appear burr.
Generally have rich experience of mold factory rarely appear because of insufficient lock force cause fly edge, because from the design, we make the mold should match with customer machine, meet the lock force, solve this problem is to reduce the injection pressure, or replace the machine, choose more point lock force injection molding equipment for production, also can be according to the specific situation to use liquidity good plastic using low pressure molding.
4. Cause by mold warping
If the mold is not rigid enough, it will be due by the injection pressure. If there are holes near the center, the holes around the holes. The burr caused by this reason is caused by poor mold making, so it is more difficult to repair.
5. Too much melt material is injected
Generally, it will not happen, usually when adjusting the machine parameters, because of the local lack of material or to prevent the shrinkage hole and inject excessive melt material, so the mold will be expanded, resulting in the generation of flying edge.
This approach is wrong, should take increased injection time or pressure retention time to shape.
6. Foreign body is present on the surface of the mold
There is a foreign body on the mold surface, which will inevitably produce a burr. Therefore, we need to check the surface of the mold before the production of the mold. In addition, after the production of the mold, we should also pay attention to timely cleaning and do a good job in daily maintenance, which can not only reduce the problems of the mold, but also prolong the service life of the mold.
Post time: Jul-17-2023