I know that Gossamer Gear has its polycryo groundsheet, which is labelled as a cross-linke olefin film. Does anyone know if it's polypropylene or polyethylene (HDPE)?
I have also heard of Valeron, which is supposed to be the toughest film available. They get this toughness (puncture & tear) by a unique orientation and lamination process among other things.
This describes how it's made by cross laminating two unidirectionally oriented HDPE films.
http://www.sigmaco.com/documents/Products/polywrap/4MILPOLY.pdf
Unfortunately, the thinnest gauge is 3 mils, which I think is thicker than the GG Polycryo.
Anybody know any more about this?
