Facts About
Foam Plastics
To the Editor:
I read with great interest your
February article on stressed-skin
panels where author Alex Wilson
compares isocyanurate (Iso) and
expanded polystyrene (EPS)
insulations. While I agree with a
number of his assertions, I wish to
clarify and expand upon some points
in his article.
First, it is evident that Mr. Wilson
has not visited an EPS manufacturing
plant, for had he done so he would
have seen a much more complex
manufacturing operation than he
would have your readers believe.
Manufacturing EPS blocks and panels
is far more complicated than
pumping two chemicals from 55
gallon drums, as is generally the case
in manufacturing isocyanurate
products.
Second, Mr. Wilson speaks of
lower R-values for EPS (R-4.17 at
40øF and