Radiation Barrier Question
Radiation Barrier Question
(OP)
I am building a carrier design to keep food hot. I have a chamber made with food grade urethane FDA approved, wall thickness ¼”. Around and on the outside I want to wrap a material that would serve as “radiation barrier”.
Any suggestion as the most effective and low cost material to use?
I have been successful with Reflective Aluminum Foil Insulation.
The outside shell will be another 1” blow molded urethane.
The objective is to keep the most heat as possible inside the chamber.





RE: Radiation Barrier Question
RE: Radiation Barrier Question
A more effective system would be aluminum foil on the inside, 1/8" urethane, 1/4" styrofoam or other expanded foam, 1/8" urethane. The foam has only about 1/10 the thermal conductivity of the denser materials, so 1/4" is equivalent to about 2.5" of the denser material.
TTFN
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RE: Radiation Barrier Question
I must have the carrier approved NSF to be commercialized.
Because of the low cost budget to start with until the concept is proved to work, I have access to a local urethane factory who is willing to work with me.
That's why the urethane chamber.
I have done numerous tests, fabricating my own carrier with aluminum chamber wrapped with reflective Aluminum Foil Insulation and a one inch low density "roof type" urethane. Results: 170 degrees after two hours. Victory!!
My problem now is manufacturing at the lowest cost possible two hundred units that will hold for at least one year of daily traffic.
The aluminum chamber was not accepted by the local health department, The chamber must be all in one piece. I had parts folded.
Thanks for your help.
RE: Radiation Barrier Question
Do different density material slows the heat escaping?
RE: Radiation Barrier Question
Just about any foamed plastic/urethane/styrene will result in something like 0.03 W/m*K thermal conductivity.
The simplest solution would be to double the thickness of your insulator and forego the reflector and see what you get. It might also help to use some sort of airgap on the bottom to minimize the direct thermal conduction going on there. A 1/2" raised ribbing or waffling would cut done the thermal conduction considerably.
TTFN
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RE: Radiation Barrier Question
RE: Radiation Barrier Question
I have signed a lease on a kitchen thinking it would be easy to come up with a carrier. Because we are dealing with food and heat, it's not that easy. I want the carrier to be a one hand held, so that it will be practical to use in a household environment. Diner for two delivered hot, safe to eat and completely table ready.
By now you can guess, engineering is not my field, I am a chef.
I have a CAD, is it safe to post it here?
Gilbert
RE: Radiation Barrier Question
If you want something "quick and dirty" I would suggest an expanded bead foam cooler like frozen foods are shipped in. You could get one that would fit a stainless steel pan with cover similar to those used for a steam table. The stainless steel pan would hold the casserole dish and all of these would fit inside of the foam cooler. This way no food is in contact with the foam and the stainless steel can be washed easily.
The foam coolers are made from expanded bead foam. A quick search turned up lots of hits. Here is an example:
http://www.styrotek.com/index.php?id=products
RE: Radiation Barrier Question
I need something that has class, I am going to upper-income households.
The cost for the mold would be in a range of $15,000.
Here is the picture of the casserole.
RE: Radiation Barrier Question