Gate Freeze

[lanny]

how do you do a gate freeze test on a hotrunner mold and a valve gate mold these gates never freeze I do not want to over pack these tools but I need to validate the process to the customer.

[rickbatey]

You do them the same. The part weight gain will slow or begin to level off more gradual versus the steep change that you would see with a cold runner. Now valve gates are a little different as if they run with enough pressure, they can close and trap the melt pressure in the cavity. For them, you do the same things but the slope will be different on your graph.
I don't make any differentiation between them when I do them. It just that the time will normally be shorter due to the technology used in the mold.
Rick

[Suhas]

Lanny, Apart from what Rick says here, I also generate a graph of part weight and hold time at a low, medium and high setting. You will get three parallel or converging graph. Look and test the parts and choose what is best for you. You can also have a window developed and have a relation between the hold time and part quality at the various pressures. I will try and post a pic soon.
hope this helps.
Suhas