Ejector mark is the phenomenon of stress whitening and stress elevation where appears on the opposite side of the nozzle facing the product, or where the ejector rod is located on the ejecting side of the tool. Why will it cause the ejector marks? The physical reason is when the demoulding force is too high or the surface of the ejector rod is relatively small, the surface pressure will be very hi...

Injection parts need to overcome the friction between parts and mold, to overcome atmospheric pressure (some semi-closed shell, cylinder parts), but also overcome the friction between the mold mechanism itself. Therefore, in order to overcome the demoulding force and ensure the stable work of injection mold, many exquisite demoulding mechanisms were born. These mechanisms can be divided ...

Product analysis This product is a check valve used in solar water heater. The material is POM. See the figure below for its appearance. As you can see from the picture above, there are threads on the outside of the product. This is not difficult. There are internal threads on the back, and the central part is not rotatable, as shown below. Demoulding of the product seems to be difficult beca...