Cashew Gate Ejection Issue

[KD Micro Molding]

We have a 2 cavity mold. The cavities are 180 degrees from each other. The runners are a straight shot from the sprue to the cavities.

During ejection the cashew gates are hooking in the gate area, and not falling from the mold tool. They are NOT breaking in the gate. Based on what we are seeing the runners are breaking and the cashews are not fully being pushed out of the gate area.

There have been multiple suggestions to resolve this issue. Adding KOs to the runner, the other was using EOAT to pull the sprue out. Please let me know what your feedback is. Thanks

[Jendalf]

Hello,

pictures always help.
tool, sprue, cashew inlet into the cavity, material, temperatures, etc.
J.

[MicaelFernandes]

Gate valve?
Did you tried diferent hold pressures?

[JayDub]

The gate is the smallest diameter region of the mold so that it freezes first, but it should also obviously be the weakest section of the part and runner. If your part is fracturing at the runner instead of the gate, that implies that there is more stress in the runner than the gates, meaning that force from the ejectors is not being transmitted to the gates. It sounds as though the cashew gates were not designed correctly. First thing I would check is that the area where the cashew meets the runner has no undercuts or dead-sharp edges that could act as stress-risers. Otherwise, adding ejectors close to the gates may help to get the force/stress where you want it.