Suggestions to help part stick to the movable plate

[kdesautel1]

For the past years I have been using a bench top injection molding machine, so I am use to opening the molds by hand and removing the part.

Recently I upgraded to a injection molding machine where the mold plates are secured to the machine.

So I'm going through the learning curve process.

I recently machined this 4 cavity mold and the issue I'm having is when I open up the clamp the part is not always sticking to the mold plate that is not stationary.

I was thinking about drilling a couple of 1/8 inch holes into the runner about 1/8" deep on both ends of the runner on the movable plate. My thought was that this may create just enough friction to get the part to stick to that plate.

Not that it makes any differance but I'm currently not using any ejector pins because I'm still in the process of working the bugs out on this process, so I wanted to walk before I ran.

I'm working with GPPS Crystal Edistir for my material

Currently my PSI on my hydrolics on the machine appear to be running at 800 psi

I am running my temp at 525 degrees F

My machine is not currently set up for automatic mode, so I'm just counting the seconds for cooling, and I am letting it cool for about 8 seconds before opening the mold.

Here are my two mold plates ( the one drawing is missing the inserts that get inserted and secured in the mold )

Thanks for any suggestions...

Kent D
Nisswa, MN

[Bryan E]

I would start with spraying the stationary side with a mold release, based on the area you spray and the number of cycles you can run between spray should be able to help you determine which modification you make to the mold. You have several uncontrolled variables that affect the process including the steel temperatures of the stationary and moving sides of the mold and what happens as you run cycles.
Good Luck

[Crabstix]

before making any under cuts - Go up on the cooling, maybe 3 or 4 seconds longer