In injection molding processing, it must be ensured that the molded product can be removed from the injection mold.
The biggest advantage of injection molding processing is that it can be mass-produced unmanned. However, if the molded product remains in the injection mold and must be taken out manually, the molding machine must always be equipped with staff, and unmanned processing cannot be performed, which will lead to Rising personnel costs.
If the mold is closed while the molded product remains in the injection mold, in the worst case, the cavity and core may be damaged, resulting in a major economic accident. If an injection mold is damaged, it cannot be easily repaired in most cases. Therefore, the injection mold must be adjusted to ensure that the molded product can be 100% removed from the mold.
So why do molded products remain in the injection mold? The phenomenon that molded products remain in the mold is called mold release failure. The occurrence of poor demoulding is the result of the joint action of the following factors.
(1) Shrinkage of molded products
(2) The thickness of the molded product
(3) Inner diameter of molded product
(4) The smoothness of the molding material
(5) Surface roughness of cavity and core
(6) Draft angle of cavity and core
(7) The surface temperature of the molded product when the mold is opened
(8) Ejection speed
(9) Number and configuration of ejector pins
(10) The corner shape of the molded product
(11) The vacuum state between the molded product and the cavity and core
(12) Orientation of glass fibers, etc.
It is difficult to see results by taking relevant countermeasures when injection mold release failure has already occurred, so it is very important to give full consideration to this in the early stage of injection mold design. Specifically, the key point is that the shape and material of the injection molded product, the position of the gate, the draft angle, the height of the molded product, the configuration of the side core-pulling slider and the inclined guide column, and the thickness of the molded product are required. etc. are fully explored to predict where release defects may occur. If predictions cannot be made, measures cannot be taken accordingly, so it is extremely important to fully understand various past demolding failure samples and failure analysis reports.
Post time: Mar-06-2023