High density foam (Transparent)

How transparent..? just to let some light through? Or clear enough to read through?

Sounds a tough one to me.... silicone prob' not clear enough. Layered bubble wrap similar. Does it all need to be transparent?

Maybe tell us more about the application...maybe there is a work around to avoid the problem rather than trying to solve it?

Thank you for your response. It is a tough one.

It doesn't have to be very clear, although it must be more than simply translucent. If an orange golf ball where placed in the middle of a meter cube, I would want to be able to see it, but not need to read it. I hope that makes more sense.

The other part is weight. It may not be realistic to believe it could be as light as high density foam, but it shouldn't be more than twice.

The bubbles in the foam need to be less than 1/4 wave of light in diameter, or they will scatter and block the light.

one way is to make an emulsion of a hyper critical amount of CO2 and your UV polymerizable monomer (which cannot be miscible with hypercritical CO2). Then you make the emulsion of the monomer = continuous phase, CO2 = dispersed phase and you mix them until it gets clear which means the size is below 1/4 wave. You may need a clear umulsifying agent too. Then you polymerize it with UV and gradually reduce the pressure to let the CO2 go to gas and diffuse out (might take a while)

ok so you've got a number of suggestions. How about some feedback? Is weight a factor? 1m³ of high density foam is pretty heavy. How does this affect anything? Are you trying to protect something or are you trying to, for instance, verify that something has stayed intact after it has been dropped for instance?

Is this a commercial project or something your playing with?

how about an update please?

Scooter

I hadn't thought that Ludtke22 might be trying to catch something, I saw something on Discovery channel recently, might have been 'How It's made', which showed a Taiwanese company developing running shoes. They demonstrated their impact absorbing foam by dropping fresh eggs from a 2nd storey balcony onto a pad of foam. they dropped 6 eggs without breaking any although in close up you could see that the egg was being rapidly decelerated.

there are some amazing "shock absorbing" foams out there. The E-A-R brand ear plugs are an excellent example of one use of the material http://209.200.67.149/pdf/hearing/ClassicSellSheet.pdf

Density looks like its in the range of 17lbs ft³.

I don't know of any of these types of foams that are transparent though.

I've also seen some "gel" like materials that are heavy but are very shock absorbing and very transparent. These could be used either in an open container to drop somethin into for rapid deceleration or to use sealed and protect something inside. The gel like materials are available in both water based silicones that can be dried back out and reduced to 1/30-1/50 of saturated size. Or they are fluids of various viscosity.

I chanced upon another version of the egg dropping video clip here.

Please forgive the late response.

I'm hoping someday for this to be a commercial product. It will be somewhat portable, thus the weight and durability concerns. It also must be able to maintain integrity while being punctured several times. Think of an archery target that can be shot by a bow 100+ times without completely deteriorating.

Have you looked into any of the polyethylene(PE) foams? DOW 200 comes to mind as well as a number of others. These can be had in a number of colors including natural which is a semi-transparent. Its used a lot in packaging. You can shine a flashlight through it and see the light on the other side but you can't see any detail on the other side, it gets too diffused by the bubbles.

What is your progress?

Not too much progress yet. I'm starting to lose hope. Most think I'll lose transparency at the high density I'm looking for. But your comment about PE foam gives some new hope. I'll look into it.

The only form that I could see this material taking is multiple thin sheets of transparent plastic material with marrow transparent spacers in between. Even then there would be difficulty seeing through it because of partial reflection at each air /plastic interface. The way to get over that it to make form sheets of plastic with non reflective coating on the surfaces.

Otherwise if you want to pack something in 1m x 1m x 1m of foam and be able to inspect its contents, X-rays are the answer.

Call Trey Moody at Armacell, they are the actual manufactures of high density foam in North America and he could ask his technical team. Here is his information.

Trey Moody
Technical Foam Sales Manager - North America
ARMACELL, LLC
Tel: (512)280-0870
Cell: (919)-215-9822
Fax: (919)304-8966
trey.w.moody@armacell.com

Norman Spence

norm10101@hotmail.com

Thanks. I'll call Trey. Regards.

There used to be a material called skeleton foam that was used for filters, speaker fronts & applications where air had to pass through, the coarser grades were partially transparent. It was like someone had made a block of foam material & then burst all of the foam bubbles. I'll try to find the supplier but I will have to dig through a pile of stuff at home.

could you use something crazy like a honey comb core material where it has visibility in one direction?

Does the material need to be rigid or do you have room for some sponginess?

I keep thinking of bubble wrap. These are obviously not foams. I'm not thinking of good solutions here. Most 2 part foams are polyurethanes and there are many clear polyurethanes but I don't know of any that combine the two properties.

This is the kind of thing I like about this forum there are some interesting challenges!

Scooter

Another source for this material is

Vicky Martinez

International Silicone Technologies

11019 Greenstone Ave

Santa Fe Springs, Ca 90670

Phone 562-946-2405

Fax 562-946-2409

sales@inter-sil.com

Thank you for the contact.

airogel is like solid smoke. is that posible? yes

Aerogel is also extremely expensive.

Aerogel wouldn't work for what we are looking for. Plus, from the YouTube link, it is way too expensive. Like high density foam, this must be able to take aggressive punctures without falling apart. Plus, we will want to mold this into forms ranging from 6 inches to several feet in thickness.

Thank you for all the feedback. This is a great tool.

I recruit for a company that does that 503 290 1158