Sealing PU foam/sheet skinned foam

[KENAT]

Question for you, we're playing round with a part that we're lining with skinned Polyurethane foam. For final units the main foam will be RIM moulded to shape.

However, for some initial units sheet foam is being used glued into place.

Also due to cost we're considering replacing one of what was going to be a specially molded part, just to have the skin, with sheet foam.

Anyone know any good ways to seal the cut edges? It needs to be able to be wiped down for clean room applications.

Our vendor doesn't seem to have any ideas and they deal with foam all the time.

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[patprimmer]

Maybe PVC plastisol.

Regards
Pat
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[Compositepro]

RTV silicone.

 

[Pud]

Brushable epoxy? Used on model aeroplanes iirc.

e.g.

http://www.seqair.com/skunkworks/Painting/Notes/Notes.html

H

http://www.tynevalleyplastics.co.uk

 

[berkshire]

Pud
The Falco is not a "Model Aeroplane"., it happens to be a fairly decent 2 place retractable gear home built full sized aircraft.

Kenat,
Is this foam a rigid urethane foam or is it an elastomer foam.
If it is rigid the epoxy will work. If it is an elastomer the epoxy will crack away when the foam is distorted.
In which case a urethane elastomer caulk or the RTV silicone may work better.
B.E.

 

[KENAT]

Thanks all.

Sorry should have been more specific in my OP.

It's elastomer foam, not the rigid type. It's main role is acoustic insulation/damping. They've formulated it to be relatively dense and have fairly slow recovery, not quite memory foam but getting there.

I think they used RTV silicone to cosmetically treat some of the joints, I wonder if they're concerned about being able to brush it over a surface and get anything like a good finish. I'm also wondering what it does do the compression properties of the foam.

I looked up PVC plastisol and it appears you have to heat cure it, is this correct? If so will that affect the foam?

Thanks again.

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[patprimmer]

I think the plastisol will cure at a temperature that normally does not damage PU.

Regards
Pat
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[ornerynorsk]

Vinyl dip foam is a very common process that will seal the substrate, make it cleanable, and prevent dusting off of the substrate for your clean room requirements.

 

[KENAT]

Thanks all. I mentioned these to our vendor, they went away and came back with an alternate material suggestion instead, at least for the part in production units.

Crosslinked Polyethylene Foam, haven't seen a sample yet but it looks like it would be OK. Haven't been able to find a really good data sheet or similar for it on the web but have found info on several sites about it being used on medical equipment with reference to clean room use.

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