In the Superfoam 320 technical specs I read that the urethane foam can use non-silicone mold: aluminium, urethane elastomers, latex, etc. May I know if I can use any of the following materials:
Aside from those 3, is there any other hard materials (plastics) that can be cut in CNC other than aluminum that can be used as a mold for Superfoam320? The reason we cannot use silicone mold is because during the foam expansion it distorts the surface and the surface doesn't come out even.
Post by carol - Alumilite Corp on Jul 19, 2016 9:29:06 GMT -5
The Super Foam 320 is a polyurethane, the nature of the polyurethane resins are they typically bond to everything but silicone. If you are using anything other than silicone you will need to use some kind of silicone release.
What are the undercuts/back drafts on this piece. That could be an issue as those types of products will work but they don't flex to release the more complicated pieces. For a simple piece, with all areas of the mold covered well and a good silicone release ... it should work.
I used a simple piece mold made from Polyethylene then I put mold release agent (Ease release 2831 from Smooth on). After that, I poured the Super Foam 320. The foam was grabing the mold really hard that it's difficult to remove the foam without breaking the foam itself.
There is no undercut in this piece at all.
Is there any other release that would work better?
Once you machine the Polyethylene it becomes really porous. I believe its the porosity that is getting you. Even though the release should be separating the PE and SuperFoam 320, there is a ton of surface texture. You might want to throw a coat of carnuba or paste wax in the mold to fill in the microscopic cracks and "seal" it, then spray release over the wax. If you can get rid of the porosity that the SuperFoam 320 is flowing and expanding into, it should release more easily.