The reasons for insufficient filling of large
Injection Molding products are analyzed from the aspects of product design,
Mold design and injection molding technology, and the corresponding solutions are put forward using modern injection molding theory. Based on the example of insufficient filling of large
injection molding parts, the insufficient filling defects of the products were analyzed, and the injection molding manufacturers found the causes of the defects and the corresponding countermeasures:
The main reasons for insufficient filling are as follows:
I. Insufficient resin capacity.
ii. Insufficient pressure in the cavity.
Iii. Insufficient resin fluidity.
Iv. The exhaust effect is not good.
As improvement measures, we can mainly start from the following aspects:
1) The injection time is extended to prevent the resin countercurrent before the curing of the gate from filling the mold cavity due to the short molding cycle.
2) Increase injection speed.
3) Increase mold temperature.
4) Increase the resin temperature.
5) Increase injection pressure.
6) Enlarge the gate size. Generally, the height of the gate shall be equal to 1/2~1/3 of the wall thickness of the product.
7) The gate is set at the wall thickness of the product.
8) Set exhaust slot (average depth 0.03mm, width 3-mm) or exhaust rod. It is more important for smaller workpieces.
9) There is a certain buffer distance (about smm) between the screw and the injection nozzle.
10) Select materials with low viscosity grade.
11) Add lubricant
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