Date: Thu, 16 Jun 1994 16:43:39 -1000 From: simonf@ariel.ucs.unimelb.EDU.AU (Simon Phillip Freidin) Message-Id: <2tr2kr$4rj@ariel.ucs.unimelb.EDU.AU> Organization: University of Melbourne Subject: Goretex as a kite material I missed the start of this thread, but I wouldn't think micro-porous teflon (gortex) is suitable as a one-way valve material for a number of reasons: 1. It is not one-way resistant to air & water. Goretex functions by the temperature differential of encasing a warm body: this drives water vapour out. Rain droplets are too large to fall through the pores. I'm not sure why it's wind resistant: Perhaps the pores are so small and widely spaced that it appears as wind resistant even though it is porous. I saw a great demo of boiling water poured into a balloon of goretex: no water dribbled off the balloon: just steam rose from the sides of the balloon: ie only water vapour is small enough to pass through goretex, and it needs a heat differential to achieve this. 2. Goretex is a rubber like material, which is given dimensional stability by bonding it to a substrate of nylon: so there is a weight penalty in using it Simon. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Tue, 21 Jun 1994 18:35:55 -1000 From: johnsen@eskimo.com (Brian Johnsen) Message-Id: Organization: Captain Pugets Roadside Taco Stand Subject: Re: Goretex as a kite material In article <2tr2kr$4rj@ariel.ucs.unimelb.edu.au>, Simon Phillip Freidin wrote: [ ] >2. Goretex is a rubber like material, which is given dimensional stability >by bonding it to a substrate of nylon: so there is a weight penalty >in using it [ ] Actually, Gortex is a spinoff of Kevlar and Teflon. Many tiny kinky little fibers are spun together into a conventional thread and woven like any other fabric. The fibers are close enough together to keep liquids >From going through due to surface tension and non-absorbtion. Don't try to use it to ward off bullets and stray ducks. It won't work. We got lots Goretex up here in the cold-wet. -- Fergie Whizes On Electric Fence Cindy Crawford Looks On Dyspepticly -- Brian Johnsen johnsen@eskimo.com = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =