Testing the Check Ring…

I received this request the other day…

I want to open up a new discussion “How to do ring plunger test (check ring) in an injection molding machine”

My Response
When referring to a check ring performance, you need to first determine what you can evaluate. Since all check rings leak, and the amount of leakage is highly dependent on the material, machine, and process, the amount of leakage cannot be easily tested.
What is important to evaluate is the consistency of the check ring leakage. Since an injection molder wants to provide a consistent product, it is critical that the molding machine deliver a consistent volume of material each shot during 1st stage fill. To test this consistency, the best method is the dynamic check ring repeatability test.
Additional Thoughts
This test is covered in detail in the following post:

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