The most expensive Snowboard Shells are made from this synthetic fabric. The history of Gore-Tex begins when W. L. Gore (no relation that I know of) invented a “thin membrane of expanded PTFE (polytetrafluoroethylene). This membrane was waterproof and breathable which amazingly stopped everyone drowning in their own perspiration by letting water in gas form out.” (www.windwood-outdoor.co.uk)
Instead of the Snowboard Shell’s breathability depending on the size of space between threads, this synthetic fabric’s breathability is directly related to its surface energy. “In reality breathability is all about surface energy. The high surface energy of the ePTFE filament makes your Gore-Tex waterproof breathable jacket hydrophobic. It's so scared of water that it can't stand it to be near it so the water is repelled. It takes a great deal of pressure to force water through, more pressure than your average downpour. So there you are, nothing to do with hole size, all to do with surface energy.” (www.windwood-outdoor.co.uk)
Due to the fact that things such as body oils, dirt and detergents clog up the spaces between the threads – thus, making a colander out of your Snowboard Shell, a second layer of modified polyurethane has been added to the shell which will absorb the moisture – in actually, this is the layer that does all of the “breathing”.
“Water coming from your body is absorbed by the polyurethane, then each molecule is transported through the polyurethane by SOLID STATE DIFFUSION... High concentrations of water (sweat) on the inside are transported to the lower concentrations on the dry outer surface of the polyurethane. It is always dry because it's underneath the ePTFE and not exposed to the elements. Here it evaporates and is transported through the ePTFE by gas phase diffusion.” (www.windwood-outdoor.co.uk)
And, that’s why Gore-Tex Snowboard Shells are expensive. |