'My job is to make sure no one is ever truly comfortable'

Scott Yorko
·8-min read

From Runner's World

Inside Gore's Environmental Testing Chamber, the ambient air temperature is a balmy 35C. Huge lights on the seven-metre-high domed ceiling beat down. Near one of the treadmills, a tester named Walter is running on the spot. Walter is an integral part of the research team, here every day helping scientists test new outdoor apparel. Sensors on his body measure sweat rate, skin temperature and range of motion. There are hoses coming out of his eye sockets.

Walter, as you may have guessed, is not actually a human. He’s a $400,000 (£300,000) mannequin with more than 100 sweating pores on his fibreglass and carbon-fibre body. And he’s just one of the high-tech tools used in the fabric and manufacturing company’s biophysics lab at its Elkton, Maryland, US, R&D facility. Next to Walter, a human college student from the nearby University of Delaware jogs on an inclined treadmill, wearing sunglasses and a lightweight wind shell. He’s strapped with a heart-rate monitor and has swallowed a thermometer the size of two paracetamol gel capsules that’s measuring his core temperature and sending real-time readings to the lab’s computers through a radio signal. Gore’s technicians will use this and other data to develop some of the most technologically advanced outdoor apparel on the market.

The company has been innovating like this since the 1950s and is best known for its namesake fabric, Gore-Tex, invented in 1969 by Bob Gore, the son of the company’s founder, when he accidentally discovered that stretching a piece of polytetrafluoroethylene created tiny air pockets in the material. The resulting breathable waterproof textile transformed the outerwear industry. And it’s in this lab that the company builds on that legacy, testing fabric innovations for apparel used in industrial and recreational settings – fighting fires, tackling chemical spills, running in the desert or riding a bike in the rain. The process involves highly proprietary systems and methodology, many details of which the company won’t divulge. But we got a peek behind the curtain to see how Gore puts its apparel to the test.

Pushing the boundaries of comfort

‘My job is to make sure no one is ever truly comfortable,’ says 40-year-old Ray Davis, the “comfort technician” in charge of the test lab. When it comes to developing outdoor gear, Davis regularly pushes testers close to their physical limits.

In fact, the Environmental Chamber where Walter and his human counterpart are running can replicate 85 per cent of the earth’s weather. The lights on the ceiling can mimic a full solar cycle from sunrise to sunset, while humidity can range from five to 98 per cent. Wondering how a garment will fare in the rainforest in the rainy season? The chamber can show you. How about against solar radiation reflecting off snow on Mt Everest? Just let Davis crank up the 72 lights overhead. The chamber needs just two hours to go between its maximum temperature (50C) and its minimum (-50C wind chill -65C in full blizzard conditions), although it uses about two-thirds of the building’s power capacity to make this temperature change.

Perhaps the most surprising aspect of the lab is that it tests for something we notice only the absence of. ‘The body doesn’t know when it’s comfortable,’ says Davis. ‘It only knows when it’s uncomfortable. We don’t have the ability to sense when we’re wet – we just notice the loss of heat.’

The best outdoor gear is actually the stuff you don’t even think about while you’re wearing it. That’s why input from both Walter and human test subjects is so important. ‘Mannequins give more reliable info than human subjects,’ says Davis. But feedback on how things feel is important, too. ‘We might have the most waterproof and durable garment in the world,’ notes Davis, ‘but if it feels like sandpaper, you’re not going to want to wear it.

Turns out dryness involves a lot of water

If you’re wondering how Gore-Tex keeps rain from seeping into a jacket while also allowing moisture to escape, it has to do with the fabric’s pore sizes — they’re large enough to let heat and water vapour out but small enough to keep external moisture, such as raindrops and snow, from entering. ‘If a water-vapour molecule is the size of a football,’ the pores are the size of a stadium and a raindrop is the size of the earth,’ says Davis.

Inside the Rain Tower, Gore’s lab techs run garments through a series of tests to determine how much water they keep out, as well as how much vapour they allow (or don’t allow) to evaporate. When a piece of apparel holds moisture, it has what’s known as evaporative resistance; it’s one of the most significant readings the lab measures. The more water vapour that stays inside a jacket from sweat and other moisture, the clammier you’ll feel. So the lower the evaporative resistance of the test subjects’ garments – meaning, the more vapour they allow to escape – the more breathable the apparel will be and the longer it will take the subjects to overheat.

‘Nothing goes to market until it passes the rain test, says Davis as he walks through the Rain Tower. With six different overhead water nozzles positioned 10 metres high, this approximately 3x3 metre glass and stainless steel room is capable of replicating any rainfall on earth that occurs between 4C and 26C at up to three inches per hour, from a light mist to a hurricane when it makes landfall.

Davis can even bend the direction of the water to simulate rain in wind speeds up to five metres per second. In the rain test, both human subjects and mannequins wear a grey cotton T-shirt or long johns beneath rain garments while walking or standing in simulated downpours. The amount of visible moisture on the undergarments indicates not just the membrane’s effectiveness in sealing out water, but also how seam tape, pockets, zips and design all work to keep water out. To simulate extreme conditions such as open-water sailing and riding a motorcycle in driving rain, there’s an additional rain room in which technicians can set up a horizontal spray that douses test subjects head-on with the equivalent of up to 56cm of rainfall per hour while they ride a stationary bike.

The floor of the Rain Tower is dotted with several drains and is measured into 25 square sections that all receive different rainfall velocities and raindrop sizes – values that Davis mapped out with a laser disdrometer. (‘That’s two months of my life I’ll never get back,’ he says.)

Durability equals comfort

When you have to worry about whether your paper - thin outerwear layer will rip on a tree branch or wear out in the wash, you’ll feel distracted wearing it –not to mention uncomfortable, should a tear in your shell let in rain. Durability is an underappreciated factor of comfort, says Davis, and that’s where Gore’s Wash Machine Area comes into play. On a large factory floor, 138 standard washing machines are rumbling like the engine room of a transatlantic cargo ship.

This is where Gore simulates the real-life wear and tear that its performance garments go through in everyday use. None of the machines have lids or use detergent and they’re all modified to run the agitate cycle in eight- hour intervals, which is tracked by a computer for each machine and piece of material. Only fabric – no actual garments – goes into these machines because buttons, zips and other features can damage the equipment over time. The fabrics go through various tests in other parts of the lab and then get washed in the machines in tap water for 500-1,500 hours. If they’re not frayed or worn out by then, they go back through the original tests again. Gore has 40 years of data using this method to compare with the results of newly developed fabrics.

Balancing all the factors that make outdoor apparel more effective and comfortable is a tricky proposition, but it ’s one that Davis enjoys. ‘When I see a large performance difference in one of our new products, that’s when we really start to nerd out,’ he says. And when Davis and his colleagues nerd out, the technology gets better and better. And so the washers spin. Down the hall, Walter runs on his treadmill. The lights in the Environmental Chamber pump up the temperature. The data keeps pouring in. Together, these unique testing facilities work to push fabrics to their limits and help scientists find out what makes even better outdoor apparel. Because the more Gore understands what makes us wet and cold and uncomfortable, the more we can forget about what we’re wearing – and the further and happier we can run.

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