Originally Posted by
HOPLOETHOS
Negative.
Gore-Tex materials are typically based on thermo-mechanically expanded polytetrafluoroethylene and other fluoropolymer products. They are used in a wide variety of applications such as high performance fabrics, medical implants, filter media, insulation for wires and cables, gaskets, and sealants. However, Gore-Tex is best known for its use in protective, yet breathable, rain wear.
The simplest sort of rain wear is a two layer sandwich. The outer layer is typically nylon or polyester and provides strength. The inner one is polyurethane (abbreviated: PU), and provides water resistance, at the cost of breathability.
Early Gore-Tex fabric replaced the inner layer of PU with a thin, porous fluoropolymer membrane (Teflon) coating that is bonded to a fabric. This membrane had about 9 billion pores per square inch (around 1.4 billion pores per square centimeter). Each pore is approximately 1/20,000 the size of a water droplet, making it impenetrable to liquid water while still allowing the smaller sized water vapour molecules to pass through.
However it was found that when used in clothing the exposed Teflon membrane layer was easily damaged, as well as being compromised by exposure to the wearer's own perspiration. As a result a third, monolithic PU layer was added, denoted in the schematic (see right)as the inner of the "protection" layers. Finally either a loose fabric shell layer, or a bonded coating (typically a grid fabric, or occasionally a carbon layer as in Gore-Tex Paclite Shell) is added to the garment to protect the membrane sandwich. This final design has been criticized as offering greatly reduced performance and more marketing benefits than performance ones.[4]
More recent fabrics such as eVent and Epic avoid the need for this inner PU coating[5] and have been shown to have higher breathability as a result, while still being rainproof
HTH...
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