The Foam is made from the same Plastic which they use to made the Sheds or the little Pipes from "Evergreen"
The difference between the Foam-Stuff and the white Sheds of Plasticcard are some kind of propellent (<---not shure about the right word)
If you don´t trust me, visit Evergreen on there Website:
<-----and then read carefully
"Evergreen Scale Models is the world's largest producer of styrene plastic shapes, strips, and sheet materials in metric and inch sizes. You can build clean, accurate models using Evergreen Scale Models products. Available at hobby shops everywhere."
If you then say, that the Sheets are PVC, then look
http://www.evergreenscalemodels.com/Sheets.htm <----here, right on top say´s:
"White Sheets Opaque White Styrene " <----Hmmmm
And if you looooooooook veeeerrrrrryyyyyyyy close, you will see that there Sheets from Styrene in 0,13 mm. And thats a huge difference to 9mm, or not?
PVC is that thing, your Floor covering is made of.
So i must say, my Friend:
You maybe used all 3 types of materials to build your stuff, but I MADE
all 3 types of materials. I WORKED
over 10 Years
with Plastics of all Kind
, and i know what i am saying. I had professional training for 3 years to become an specialised Worker for Plastics.
Ok, i must say, i misspelled maybe the Styrene<---->Polystyrene-thing, but in Germany we use the words this way (Styrene (Styrol) is the basic Molecule which the Polystyrene (Polystyrol) is made off. The small word "Poly" means something like "more of the same kind").
I don´t want a apology about your posting, Bloodhound. But i must say that it is wrong from you to say i am so wrong, without even try to use google before you are posting.
I posted some links to Wiki above....i don´t believe you read them, or did you? Cos then you may have seen, that my posting was corectly.
I just google a little and found this link:
So you an see,against your words, even GW sayes "Styrene"