Earlier this month Kevin Back of Powder Magazine very graciously brought a few of us heli skiing in Girdwood / Alyeska, Alaska with the Chugach Powder Guides.

I took the opportunity to continue to put our new soft shell fabric, Polartec Power Shield Pro, to the test in the field (it’s tough work but has to be done).

We arrived on a rare blue-bird day in Anchorage with views of Denali and a beautiful ride south along the Turnagain Arm to the resort in Girdwood. That night the clouds picked up, a storm moved in and we were blessed with about 40″ of light fresh powder over the next 36 hours.

Alaska this time of year can be surprisingly warm and damp (tip – bring multiple pairs of goggles for cat / heli skiing in Alaska) – so it was an excellent environment to really put Polartec Power Shield Pro through its paces.

That’s me in the video tele skiing in the pinkish raspberry outfit (that’s what happens you let engineers pick the sample fabric colors). I took some heat from the guides and other groups of skiers – but all in the name of fabric testing…

We skied in a range of conditions from the high teens Fahrenheit to the mid 40’s – everything from blower powder to heavy wet snow – howling winds to baking sunshine.

Throughout the week, I wore the exact same set of clothes (occasionally adding another layer of Polartec Thermal Pro high loft when temperatures dipped). I was super impressed with the comfort range Polartec Power Shield Pro offers – wind resistant enough, yet allows some true airflow through the fabric to keep from overheating. The jacket and pants also did an excellent job of moving moisture vapor away and keeping me dry inside both by venting sweat vapor and by keeping the wet snow and water out (even when kneeling in slush to clamp down my Black Diamond O1 tele bindings and leashes).

Overall the trip was a total success – great conditions delivering over 80,000 vertical skied and Polartec Power Shield Pro outperformed what either a traditional hardshell or traditional softshell could have done. It was the perfect balance for widely variable conditions. This fabric is available Fall 2010 in North America from The North Face in the Kishtwar jacket and in Europe will be offered by TNF, 66 North, Eider, Millet, TrangoWorld, Norrona, Montura, and Lowe Alpine. Check it out.

PS – these photos and video were shot and edited by Adrian Glasenapp – thanks Adro!

Nate Simmons Heli Skiing Alaska

Photos by Adrian Glasenapp

(click to enlarge)

For many years the outdoor industry has relied upon the Water Vapor Resistance or RET (Resistance of Evaporation of a Textile) test to measure the “breathability” of water resistant/waterproof fabrics. This test,”compare(s) the ability of different materials to dissipate moisture vapor from the body of the wearer to the outside.” (WSA Jan/Feb2010)

However, in our opinion, the RET test (ASTM F1868 -09) does not accurately evaluative the true breathability of a fabric. In fact, “studies have confirmed that the test is predominantly influenced by the fabric thickness, rather than the pore characteristics of the fabric.” For example, the RET test yields a result that says a three layer hard shell/waterproof fabric is more breathable than a 200 weight fleece. Anyone who has ever worn either of these fabrics knows that’s not true – fleece is almost infinitely breathable (hence the reason Polartec has created other more wind resistant fabrics over the years). In addition, RET tests are affected by clothing weight, drape and tightness. Perhaps most importantly, RET not allow any air movement during the test, so you get some truly bizarre, lab-only results.

Another standard test used by the textile industry to measure breathability is Moisture Vapor Transfer Rate (MVTR). MVTR measures how much moisture vapor can pass through fabric in a 24-hour period and there are over 30 different tests to assess this transfer rate. However, these tests can yield wildly different results (as chronicled in this great post on Patagonia’s blog) and like the RET test, MVTR is static and does not account for real-world conditions where air flow is always present.

As an alternative, Polartec is promoting a better means of evaluating the breathability of water resistant and waterproof fabrics. The Dynamic Moisture Permeation Cell (DMPC) is an ASTM standard test that evaluates a fabric’s ability to move moisture vapor in dynamic conditions. The test can change air pressure and humidity on each side of the fabric and measure how well it truly breathes as conditions change (like the real world). DMPC was developed by Dr. Phillip Gibson, a civilian scientist working with the US Army. Click here to download an interesting story about Dr. Gibson’s testing from the June 2004 issue of Inside Outdoor magazine.

In the chart posted above as you move to the right on the horizontal axis, you can see that Polartec Power Shield Pro (the blue line) breathes more and more as you increase the pressure – this is roughly equivalent to increasing air speed or wind – like going from standing still to walking to a light jog. The harder you work, the harder the fabric works (both convection and diffusion are at work when air is moving). Meanwhile, the orange line represents a full-film softshell fabric – the line is flat meaning breathability does not change. This translates to a damp sweaty user experience as exertion levels increase.

Polartec has always emphasized air permeability. Even tiny, tiny amounts of air flowing through the fabric massively increases a fabric’s ability to move moisture vapor away from your body. Fabrics without airflow require a significant amount of heat and moisture vapor to build up inside the jacket before they start to work. We have all experienced the sweat-box feeling of a fabric that relies only on diffusion to “breathe.”

Fall 2010 a range of jackets will be available in the new ultimate soft shell – Polartec Power Shield Pro. For more on Polartec Power Shield Pro, scroll down to see previous posts on the fabric launch and on Polartec’s partnership with Finetex.

Staying dry is the key to comfort year-round and base layers are the most critical layering choice in the winter. If your current clothing system isn’t keeping you warm enough, upgrading the fabrics next to your skin can be the most cost effective way to be warmer – this is especially true for start and stop activities where you sweat and then chill.

The main stage.

2nd Stage

Polartec receives yarn from one of its yarn vendor/partners, Unifi in North Carolina, on recyclable pallets. Trucks return to Unifi with empty pallets and also fabric scraps that can be recycled into new yarn. In 2009 30% of Polartec’s production will use recycled content yarn saving millions of pounds of CO2 emissions each year.

Dozens of spools of yarn feed into a circular knitting machine at Polartec’s main production facility in Lawrence, MA, USA. Different yarns and constructions can be combined to create hundreds of different fabrics with specific performance attributes. As the fabric is knit, it rolls up inside the bottom of the machine creating what looks like a giant terry cloth tube sock. Later this “tube sock” is slit down the middle to create flat fabric.

From the circular knitting machines, rolls of greige fabric await quality inspections before going to dyeing and finishing. These rolls look like giant terry cloth tube socks before the tube is slit to create a flat piece of fabric.

As greige goods come off the circular knitting machines, the fabric runs past a light for quality inspection. This happens before the fabric is slit, dyed, and finished.

Greige goods are dyed in “jets” that look like giant front loading washing machines. These jets apply heat and pressure to lock in color as well as performance enhancing treatments like odor resistance, anti-static, and wicking agents. New dye jets use 50% less water.

After the dye jets, a machine wrings out the fabric and then slits the fabric to create one flat piece which is then dried before finishing. Fabric next moves to be napped and then sheared in finishing.

Finishing the fabric is the process of the loops in the fabric and then shearing the yarns to an even height. This is a specialty of Polartec’s which creates long lasting, non-pilling fabrics. In this video, giant rollers covered with small wires break the loops in the fabric to create loft for warmth without weight.

Finished Polartec fabric is inspected for quality before it is shipped to apparel manufacturers.

A Martindale machine tests abrasion resistance on Polartec fabrics.

Pilling test for Polartec fabrics.