[Image above] The North Face team captain alpinist Hilaree Nelson puts the company’s new performance material, Futurelight, to the test. Credit: The North Face
Depending on where you live and your attitude toward winter, some of you may be cursing the cold. Others instead are surely celebrating the fact they had a white Christmas. But I have another reason to be happy that temperatures are falling—snow sports.
Although I am not keen to remain stationary and freeze amidst the falling snow, I find winter peaceful and beautiful as long as I’m exerting physical activity to stay warm.
For anyone who enjoys winters sports, whether snowboarding, skiing, snowshoeing, or good old-fashioned sledding, you know that cold weather outerwear has come a long way in the past few decades. Whereas old-school apparel was bulky and stuffy and often left you feeling stuffed with marshmallows, today’s outerwear options are much more comfortable, low profile, and breathable.
Although you may take this progression for granted, it has been no small feat, and in fact it is one filled with materials science.
Designing gear to perform in inclement weather is a conundrum—it requires a balancing act of just the right materials properties to sequester the elements on the outside, whether rain, wind, or snow, yet still allow water vapor to pass through. That water vapor, aka sweat, needs to be able to evaporate and dispel away from the body to keep the wearer at a comfortable temperature—evaporative cooling at its finest.
For instance, an effective rain jacket needs to be able to prevent water droplets from passing through the material yet still allow water vapor to escape. A waterproof fabric that blocks passage of all water molecules, while a safeguard against external moisture, would block sweat from escaping entirely—a situation that would end up soaking the wearer with their own perspiration, defeating the jacket’s ultimate purpose. So it is a Goldilocks-type feat to design a material with just the right size of pores to perform both functions.
Luckily for us, within the past several decades a revolution took place with the development of such waterproof yet breathable fabrics, most notably the accidental development and commercial success of a material called Gore-Tex.
Material-wise, Gore-Tex is essentially stretched Teflon, expanded so that the polytetrafluoroethylene material is pocked with lots of tiny pores just the right size—too small for water droplets to permeate yet big enough for sweat vapor to escape. Because the material revolutionized waterproof yet breathable fabrics, Gore-Tex commanded an intimidating lead in the performance fabric market for the past several decades.
Yet the conundrum of waterproof yet breathable fabrics is one that materials engineers are still tweaking to increase the performance and comfort of the gear these fabrics constitute.
Could electrospinning—the same technique used to fabricate ceramic sponges, icephobic membranes, battery materials, and much more—offer the ultimate solution?
Outwear company The North Face certainly thinks so. The company has invested considerable research and development into its new Futurelight material, a nanospun performance fabric the company debuted at CES 2019 and is currently marketing in various performance apparel products.
Futurelight is designed to be more breathable and lightweight than any other performance material currently on the market. And unlike Gore-Tex, it is free of perfluorocarbons, which is important because of environmental considerations.
Futurelight’s results from independent testing by Underwriter Labs are indeed impressive. “The lab certified Futurelight as totally waterproof using a test that exceeded firefighter standards by dumping 235 gallons of water per hour on the garment. With the highest level of cubic feet per minute of airflow and highest moisture vapor transmission rate of any waterproof fabric ever tested. That means, that while waterproof, The North Face finally solved the breathability problem,” according to a Popular Mechanics article.
That solution comes from Futurelight’s use of nanospun fibers, which are fabricated using electrospinning to fabricate a thin and lightweight porous film that can be transferred onto fabrics.
Futurelight is not the first performance fabric to incorporate nanospun fibers, although it may be the most heavily financed—The North Face is investing $20 million in marketing alone for Futurelight, in addition to countless dollars already spent on material research and develop as well as establishing its own manufacturing processes.
“The [electrospun nanofiber] technology was introduced most notably in Polartec’s Power Shield Pro and NeoShell fabrics, which debuted in 2009 and 2010, respectively, though with far less fanfare,” according to a Gear Patrol article. “The North Face concedes the membrane construction is similar to past products but notes points of differentiation in the process—notably, the brand developed its own machines to produce the material in a factory that makes electronic insulating elements outside of Seoul, South Korea.”
Developing its own manufacturing chain allows The North Face to spin its fibers at different weights, with control of fiber density and fiber diameter to create materials tuned for different activities and specific environments, for instance. The company is currently offering three lines of Futurelight gear aimed at different activities, particularly snow sports, running, or climbing mountains.
The thin and light nanospun fibers allow Futurelight to be almost aerogel-like in its high air content—the lowest weight of the material contains 85% air, down to 72% air in its heaviest weight. Offering such high performance with such low weight and profile allows The North Face to combine films of the nanospun fibers with various other backer and facing materials (i.e., sandwiching the films within other fabrics or materials) to offer impressive versatility in performance gear.
That versatility is a feature that The North Face is marketing in Futurelight. “We have far more freedom to dictate what that end material package is,” The North Face global creative director of performance Jason Israel says in the Popular Mechanics article. “Another component that popped out of this was the ability to have stretch … something not common in the waterproof space.”
Whereas many other waterproof breathable fabrics are stiff and crunchy, the nanofibers mean that Futurelight does not have to be—countless gear reviews of Futurelight products cite that their most notable feature is how soft and comfortable they feel and wear.
“Imagine a waterproof t-shirt, sweater or even denim that you actually want to wear,” Scott Mellin, The North Face’s global general manager of mountain sports, says in a Quartz article. “Today we start with jackets, tents and gloves, but the possibilities could be endless.”
The abilities of performance fabrics, such as The North Face’s Futurelight, are measured with various lab tests, including assessments called cup tests, inverted cup tests, sweaty hot plates, and sweaty mannequins. These tests are used to measure industry-standard parameters such as moisture vapor transfer, which measures how much water vapor can pass through the material per square meter per day.
In all such parameters, Futurelight’s data are impressive. Its moisture transmission speed is 75,000 g/m2/day, whereas a similar waterproof/breathable material called eVent boasts just 30,000 g/m2/day. In addition, Futurelight has an air flow rate of 1.5 ft3/min, whereas the most breathable fabrics on the market currently are closer to 0.2 ft3/min and current waterproof/breathable fabrics are 0.07–0.09 ft3/min.
“And it can be endlessly tweaked. They can make the Futurelight membranes thicker and more dense for a more durable membrane, or thinner and lighter for a more breathable one. In theory, this means they can use Futurelight fabric in a wide range of applications, from jackets and tents to sweaters, denims, or T-shirt dresses,” according to a Wired article.
With such versatility and performance, it looks like the future of performance fabrics could be entirely altered by nanospun fibers like Futurelight. As for my snow activities this winter, however, I’m going to stick with my Gore-Tex lined jacket for now—Futurelight products are starting at price tags in excess of $250.