Gore-Tex: a membrane that significantly changed the waterproofing possibilities of textiles
Gore Tex is the trade name for a membrane that is impermeable to water and at the same time open to the diffusion of water vapor. It owes its name to the American chemist Robert W. Gore, who invented it in 1969. Its main component is polytetrafluoroethylene, which is also the chemical component of Teflon. To create the microporous membrane, the PTFE is thermomechanically stretched. 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, which makes it impenetrable against it. For the water vapor molecule there is no problem in going through the small pores, because they are smaller than the liquid water molecules. This makes Gore Tex fabric perfect for textiles, as they can be waterproof and windproof, but also breathable. This was not possible before, since there were no materials that offered the same characteristics. There were only fabrics that were waterproof, but not breathable. For example, plastic or waxed textiles. The first textiles with a Gore-tex membrane were produced and marketed in 1976, after the inventor obtained a patent for the material.
The main disadvantage of Gore-Tex is that it is only functional when the osmotic pressure between one side of the membrane and the other is high enough, which means that the temperature difference must be high enough. Therefore, the Gore Tex membrane of a common garment will stop being breathable when the outside temperature exceeds 15-18 °C. Then the sweat will condense on the inside of your clothes and you will get wet inside.
Anyway, in textiles, it’s not just the Gore Tex membrane that makes them waterproof.
If only the raw membrane were used, the products would not be very durable. So, manufacturers use a “sandwich” of different materials to provide protection for the central membrane. These materials also have to be breathable, because if they aren’t, it wouldn’t make any sense to use Gore-Tex between them. Two typical outer shell materials are polyester and nylon, which are strong enough to withstand the hazards of everyday use. On the inside of the fabric there is also a protection and, in addition, a material that makes the fabric comfortable to wear, such as fleece.
So today you can get any type of textile that uses the benefits of Gore-Tex fabric. For example jackets, gloves, shoes, trousers etc… But also other areas make use of the outstanding features, for example it is also used for medical implants, insulation for cables, filters or various bicycle parts.
