Gore Tex – A Membrane Which Changed the Waterproofing Possibilities on Textiles Significantly

Gore Tex is the trade name of a membrane which is impermeable against water and in the same run open to the diffusion of water vapor. It was named after the US-American chemist Robert W. Gore, who invented it in 1969. Its main component is the polytetrafluoroethylene which is also the chemical component of Teflon. To create the micro porous membrane, the PTFE gets thermo-mechanically extended. This manufacturing technique was the main invention of Robert W. Gore.

The membrane works like this: Its pores are about 20,000 times smaller than a drop of water, what makes it impenetrable against it. For the molecule of the water vapor it is no problem to get through the small pores, because they are smaller than the molecules of liquid water. This makes the Gore Tex fabric perfect for textiles, because they can be water- and windproof, but also breathable. This was not possible before, as there were no materials which provided the same characteristics. There were only fabrics which were watertight, but not breathable. For example plastic, or waxed textiles. The first textiles with the Gore tex membrane were produced and sold in 1976, after the inventor had gotten the patent on the material.

The main disadvantage of Gore Tex is, that it is only functionally when the osmotic pressure between the one and the other side of the membrane is high enough, what means that the difference of the temperature must be high enough. So the Gore Tex membrane on a common piece of clothing will stop being breathable when the outside temperature is above 15-18 °C. So the sweat will condense on the inner side of your clothing and you will get wet on the inside.
Anyway on the textiles it is not only the Gore Tex membrane which makes them waterproof.

If only the raw membrane would be used, the products wouldn’t be very durable. So the manufacturers use a “sandwich” of different materials, to provide protection for the core membrane. These materials have to be breathable too, because if they are not, it wouldn’t make any sense to use Gore Tex between them. Two typical outer protection materials are polyester and nylon, which are strong enough to resist the dangers of everyday use. On the inner side of the textile there’s mostly also a protection, and additionally a material which makes the cloth comfortable to wear, such as fleece.

So today you can get any kind of textiles which use the benefits of the Gore Tex fabric. For example jackets, gloves, shoes, trousers etc… But also other areas make use of the outstanding characteristics, for example it is also used for medical implants, insulation for wires, filters or several parts of bicycles.