[jai_helsing]

Hi Everyone,

We recently go into Vacuum forming process. We mostly form 0.125'' HDPE sheets to build fenders and other panels. I know from online research that HDPE has high shrinkage rate and needs to be controlled carefully.
So once the molds are pulled, how long should one cool them? I wanted to know the timings of the cooling cycle. Also based on the few trial parts pulled, which were cooled to room temperature before taking off the machine.
I have observed that the parts warp a lot. Should the parts after being pulled and cooled, still be mounted on a fixture to control warp and further shrinkage? I am having a lot trouble dealing with the shrinkage and how to control it.
And advise, manuals or documents on this would be truly appreciated.

Thank you.

[Tbuck85]

Jai,

Did you ever get any help with the shrinkage and warping issue? I am having the same problem trying to form table tops.

[Allplastic]

Hi Jai
Please provide a photo of your machinery and ill try to help as much as i can.