Machinable thermally insulating foam for containing liquid nitrogen
Machinable thermally insulating foam for containing liquid nitrogen
(OP)
I am doing some cryogenic experiments and need to make some special shaped baths to contain liquid nitrogen for short time.
I have to be able to machine to complex shapes to fit around apparatus. Have been using a rigid foam(PU I think, for building insulation) about 100 mm thick and cutting on milling machine to shapes around 200 mm X 150 mm and coating in epoxy and glass fiber cloth. Messy and weak but works OK
Dewar that holds liquid nitrogen seems to be insulated with a LDPE foam.
Could anybody recommend an cryogenic insulating material I could cut on milling machine to various shapes
I have to be able to machine to complex shapes to fit around apparatus. Have been using a rigid foam(PU I think, for building insulation) about 100 mm thick and cutting on milling machine to shapes around 200 mm X 150 mm and coating in epoxy and glass fiber cloth. Messy and weak but works OK
Dewar that holds liquid nitrogen seems to be insulated with a LDPE foam.
Could anybody recommend an cryogenic insulating material I could cut on milling machine to various shapes





RE: Machinable thermally insulating foam for containing liquid nitrogen
Dan
www.eltronresearch.com
Dan's Blog
RE: Machinable thermally insulating foam for containing liquid nitrogen
Neither PE foam nor styrofoam are very machine-able. A more typical construction technique is to form the shell from sheet material, and inject (or pour) urethane foam into the hollow interior (or steam-expand styrene foam pellets). Polyethylene sheet as a cover for injected/expanded PU foam would be a pretty good combo., I'd think.
RE: Machinable thermally insulating foam for containing liquid nitrogen
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RE: Machinable thermally insulating foam for containing liquid nitrogen
I know locally that cryogenic shipping containers are Styrofoam with a heavy duty corrugated paper board cover.
I was involved in project where we did machine some special containers from modeling or pattern board. These materials are mostly urethane foam of various densities. You could use the low density material to machine and then insert in into a Styrofoam shell.
I definitely would give Freeman a call
h
RE: Machinable thermally insulating foam for containing liquid nitrogen
Dan
www.eltronresearch.com
Dan's Blog
RE: Machinable thermally insulating foam for containing liquid nitrogen
And a good vacuum cleaner. ;)
RE: Machinable thermally insulating foam for containing liquid nitrogen
Thanks
RE: Machinable thermally insulating foam for containing liquid nitrogen
Renshape is "just" urethane foam in various densities. (I'm sure there are some benefits to the real McCoy, besides fancy coloring agents :). The lower density urethane foams will give better insulation properties, at the expense of structural strength/stiffness, and vice versa. Talk to a local machine shop or their tool supplier, a plastics supplier, or shop material supplier. Some other terms used for the stuff include "butter board" and "prototyping foam".
RE: Machinable thermally insulating foam for containing liquid nitrogen
http://www.huntsman.com/
RE: Machinable thermally insulating foam for containing liquid nitrogen
supply stores.
If you have to bond the PU foam make sure you follow the manufacturer's bonding instructions.