Re: styrofoam - thermal conductivity

[brian whatcott <inet@INTELLISYS.NET>]

At 17:58 1/18/99 -0500, you wrote:
> I would like to know the thermal conductivity (with proper units) of the
> disposable styrofoam cups so commonly used to serve coffee.
>
> I believe styrofoam is about 5% polystyrene and commonly 95% CO2 or Pentane
> (sometimes air or other gas?), therefore the thermal conductivity (K =W/m/C?)
> is probably close to that of the air or gas used.
>
> If no thermal conductivity data is available, confirmation of the 5%
> polystyrene and identification of the trapped gas will help.
>
> Thank you in advance.
>
> Owen von Kugelgen
> High School Physics Teacher
> (kugelgen@aol.com)
In a standard European reference
(Materials: Mitchell's Building Construction, Alan Everett)
thermal data are given for four variants of different density:

Expanded:       16 kg/m^3    0.035 watts per meter.degreeC
Bead board:     24 kg/m^3    0.033
Extruded board: 32           0.035
Extruded with
surface skin:   40           0.032

watts per meter.degreeC is a measure of bulk volume conductivity.

The usual American unit of measure is different and not quite as
convenient for you.

Brian
brian whatcott <inet@intellisys.net>
Altus OK