What is Gore-Tex?

A common question we often get asked is what actually is Gore-Tex (or GTX)? This magical material pops up all over the place and is used in the very best of outdoor clothing, but what makes it so special? And why should you use it?

Today we’re breaking down these mysteries and welcoming you into the wonderfully (waterproof & weatherproof) world of Gore-Tex! Grab an umbrella, because things are going to get wet!

In its most basic form, Gore-Tex is a waterproof, breathable fabric membrane that due to it’s lightweight, stretchy and resistant properties, makes absolute perfect sense to use in outdoor wear…but as you’ll find out, it’s SO much more!

History of Gore-Tex

As with some of the best inventions in mankind’s history, Gore-tex actually came about as somewhat of a happy accident. Co-invented by Wilbert L. Gore and Gore’s son, Robert W. Gore in 1969, Gore-Tex was first created as the duo were stretching heated rods of polytetrafluoroethylene (PTFE – or teflon to you and me) to create expanded polytetrafluoroethylene (ePTFE). What wasn’t expected however was instead of slowly stretching the heated material as you usually would in these conditions, Robert applied a sudden, accelerating yank. The solid PTFE unexpectedly stretched about 800%, forming a microporous structure that was about 70% air.

All of these properties were then fine tuned to produce a material that can repel liquid water while allowing water vapor to pass through. Thanks to it being comprised of 70% air, Gore-Tex is lightweight, waterproof and can be used for almost all-weather uses. (You’ll even find it in astronaut suits!)

Robert Gore demonstrating the elasticity of Gore-Tex

How Is Gore-Tex Used?

Gore-Tex is super malleable and versatile so is used in everything from, medical implants, filter media, insulation for wires and cables and even sealants. However, Gore-Tex fabric is best known for its use in protective rainwear.

The simplest sort of rain wear is known as ‘a two layer sandwich’ and unsurprisingly, it exactly what it sounds like. An outer layer is typically woven nylon or polyester and provides strength whilst an inner layer provides water resistance, at the cost of breathability.

Gore-Tex took this idea and threw it out the window, creating a material that does both of these jobs in one. The membrane on Gore-Tex had about 9 billion pores per square inch (around 1.4 billion pores per square centimetre). Each pore is approximately ​1⁄20,000 the size of a water droplet, making it impenetrable to liquid water while still allowing the more volatile water vapour molecules to pass through.

The outer layer of Gore-Tex fabric is then coated on the outside with a Durable Water Repellent (DWR) treatment. The DWR prevents the main outer layer from becoming wet, which would reduce the breathability of the whole fabric. However, the DWR is not responsible for the jacket being waterproof. Without the DWR, the outer layer would become soaked, there would be no breathability, and the wearer’s sweat being produced on the inside would fail to evaporate, leading to dampness there.  The DWR can be reinvigorated by tumble drying the garment or ironing on a low setting.

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Which Brands Use Gore-Tex

Rab have recently been incredibly busy with Gore-Tex and both their new meridian jacket and Zenith jacket feature Gore-Tex. Likewise, you’ll even find Gore-Tex in footwear! The new HanWag Banks GTX features Gore-Tex within it’s lining to help reliably keep feet both breathable and dry! 

So it’s pretty safe to say that Gore-tex is one of the most highly regarded materials on the market. If you come across any item with ‘GTX’ or Gore-Tex in the name, you’ll know you’re shopping in safe hands! Have more questions about Gore-Tex? Our team would be happy to help!

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