Gore-Tex created a thin waterproof-breathable membrane of expanded PTFE (polytetrafluoroethylene) about 30 years ago and has dominated the waterproof-breathable rainwear category ever since. eVent’s more breathable technology has challenged Gore-Tex - and Backpacking Light has emphasized that difference for the benefit of our readers - but Gore’s marketing has nevertheless established Gore-Tex as the “gold standard” for waterproof-breathable jackets. Finally, after many years with Gore-Tex as the status quo and little change, Gore’s supremacy is being challenged by a number of companies introducing new technologies and backing them with marketing efforts sufficient to bring about significant change in this category. And technology-loving outdoor enthusiasts, like our readers, are the spectators cheering them on as well as the beneficiaries of the improved performance.
One thing the Gore-Tex challengers have in common is that they all have Gore-Tex in their crosshairs. Here is Columbia’s display at Winter 2011 Outdoor Retailer.
We are seeing the beginning of a waterproof-breathable fabric revolution, where new innovations are being marketed on the basis of technology differences, rather than just hype (but the hype is still there, for consumers who don’t want to be bothered with fabric technologies and physics). The challengers are actually explaining the technology (somewhat) to help consumers understand how their innovations can possibly be better than Gore-Tex.
We are already familiar with Gore-Tex and eVent. By no means are they standing still; Gore is introducing Active Shell, their lightest, best performing construction yet, and eVent has expanded their outreach by offering “customized solutions and branding flexibility.” The new players are: Columbia, which is rolling out their Omni-Dry technology this spring; Polartec, which is introducing NeoShell this fall; and Mountain Hardwear, which is introducing DryQ this fall.
That’s a total of five major players providing new technologies in the high-end waterproof-breathable fabric category. All are claiming to be different from each other, and all are claiming to be more breathable compared to the “industry standard” (aka traditional Gore-Tex). And many are focusing on thinner, lighter fabric constructions to create garments that perform better in high exertion activities.
It’s the biggest wave of new waterproof-breathable technologies ever, so what are the differences?
The Key Differences
Because of marketing, Gore-Tex has become the gold standard for waterproof-breathables. But we all know that Gore’s approach puts more emphasis on the word “waterproof” (“guaranteed to keep you dry”) than it does on the word “breathable.” Indeed, Gore-Tex garments are waterproof, at least for the first year or so, but breathable - that’s a stretch. Gore-Tex breathability, which is based on vapor diffusion, requires the interior of the jacket to warm up sufficiently so sweat turns into water vapor, because only water vapor can escape to the outside through the membrane’s tiny pores. In Alan Dixon’s classic article on Waterproof Breathable Fabric Technologies: A Comprehensive Primer and State of the Market Technology Review, a key point he makes is that Gore-Tex is most efficient at transferring moisture at high humidity levels. That means the wearer must first get the jacket steamed up real good inside, then its “breathable” performance kicks in. You might legitimately ask: “why pay big bucks for that?” or “they call that breathable?”
The anatomy of a traditional Gore-Tex fabric construction. The lower layer labeled “protection” is a thin polyurethane layer to protect the ePTFE membrane from becoming fouled by body oils, sunscreen, insect repellent, etc. It’s also the weak link because it minimizes the air permeability of the membrane.
To address this issue, many manufacturers have added workarounds to Gore-Tex jackets like pit zips and core vents to provide more ventilation, to help vent moisture and improve comfort. Note however that supplemental ventilation is counterproductive to breathability through the Gore-Tex fabric, because ventilation lowers the humidity, so there is less diffusion of water vapor through the membrane. If that’s the case, then what is the membrane accomplishing?
Enter eVent and three newcomers. The key difference in their technologies compared to Gore-Tex is air permeability, which allows moisture transport by convection as well as vapor diffusion. The nemesis to breathability in Gore’s waterproof-breathable construction is a thin polyurethane layer necessary to protect its ePTFE membrane from becoming fouled by body oils. The polyurethane layer limits Gore-Tex’s breathability to the process of vapor diffusion only, and eliminates any air permeability directly through the fabric. eVent’s breakthrough is their oleophobic (oil-repellent) ePTFE membrane that does not require a protective PU layer; thus the fabric does have some air permeability, which enhances the direct venting of water vapor and wearer comfort.
All of the challengers to Gore-Tex target its weak link, which is the lack of air permeability. All of their technologies are air permeable to some extent, and emphasize that a small amount of air permeability is all that’s needed to eliminate enough moisture to make a jacket feel significantly more comfortable at higher exertion levels. They quickly follow this up by saying that only a small amount of air permeability is sufficient, and there is no loss of functional windproofness.
To illustrate the differences by the numbers we have so far, Polartec NeoShell has 0.5 cubic feet per minute of air permeability, which gives it a huge breathability advantage over Gore-Tex (0 cfm) and eVent (0.1 cfm). I obtained these numbers from a Polartec representative, who emphasized they were produced by an independent testing lab. The numbers indicate that we should expect significant and perceivable performance differences among these technologies. We know that to be true in our past comparisons of Gore-Tex and eVent, and by extension, we should expect NeoVent to be better yet.
Now let’s take a look at the individual technologies.
Gore-Tex Active Shell
Not to be outdone, Gore launched Active Shell in fall 2010, which Gore says is the most breathable waterproof laminate the company has produced. Active Shell will appear in garments by a number of manufacturers in fall 2011.
Gore-Tex Active Shell construction (left). The Mammut Felsturn Half-Zip (right, 10.2 oz/289 g for size men’s Large, US$390, available fall 2011) will be one of the lightest Active Shell jackets available. It’s intended for light and fast mountaineering.
Active Shell is based on Gore Activent, a fabric introduced in 1995 that was primarily used in windshirts. Activent was highly breathable and water-resistant and popular among endurance athletes. The advanced version, Active Shell, is claimed to be much better as a result of a new construction process that Gore has developed. Conventional Gore-Tex is a sandwich of an outer shell fabric glued to the ePTFE membrane, a thin polyurethane layer glued to the membrane, and a liner fabric glued to the polyurethane. The glue consists of thousands of microdots, which adds weight and cuts breathability (in addition to the polyurethane layer). In the new construction, the polyurethane layer itself acts as an adhesive to bond a thin tricot lining to the membrane. In addition, the membrane is thinner and the lining fabric is stretched to make it thinner and more comfortable against the skin. To be sure that Active Shell garments are as light and breathable as possible, Gore stipulates that garments must have a close fit, few pockets and/or mesh pocket linings, and as little taping as possible.
Note in the above description that the polyurethane layer is still present, so, in spite of the advances, Gore Active Shell continues to be a traditional construction which is dependent on vapor diffusion for breathability. Specifically, the reduced weight and increased breathability are the result of the elimination of glue layers, thinner membrane, thinner face and lining fabrics, and garment design.
To help put the different Gore-Tex fabrics into perspective, Performance Shell is for general use, Pro Shell is for mountaineering and professional use, Paclite is “emergency rainwear” to be carried in a pack and used only when necessary, and Active Shell is intended for high exertion activities like runners, cyclers, and fast-moving mountaineers. A key point is that Active Shell is comfortable worn against the skin (unlike Paclite), which can further enhance its performance in higher temperatures.
eVent technologists conceived and developed the concept of membrane air permeability combined with sufficient waterproofness, and found a way to make the ePTFE membrane oleophobic without adding a polyurethane layer. Although this approach provides a better waterproof-breathable performance fabric, market forces have relegated eVent to a smaller role in the marketplace, appreciated mostly by technically oriented outdoors enthusiasts.
The zipperless Montane Spektr Smock, weighing just 7.4 ounces (210 g), is the lightest eVent jacket available.
eVent’s reaction to the current waterproof-breathable fabric revolution taking place is to be supportive and flexible (bring it on!). Their marketing strategy will become much more partner-friendly, as suggested by the following pitch prominently displayed at their Outdoor Retailer booth: “Your technology on the outside; our technology on the inside.” GE Energy, owner of the eVent technology, will roll out two approaches to working with partners: 1) a manufacturer may choose to capitalize on eVent’s current reputation and incorporate the industry-known eVent name on their finished products, or 2) manufacturers may choose to combine the eVent membrane with their own knowledge of fabrics, laminate making, and garment construction, and brand them as their own. This means there will be OEM eVent products hitting the marketplace, much like what has happened with polyurethane laminates - it seems like every manufacturer has their own proprietary fabric. Personally, if that’s what it takes to get better technology into the marketplace, then I’m all for it, but the consumer confusion factor will increase dramatically; it will no longer be a simple comparison of Gore-Tex versus eVent.
Polartec as a company has been very aggressive in rolling out innovations. From Outdoor Retailer Summer 2010, I reported on Polartec Power Shield Pro fabric, which is claimed to block 99% of the wind and provide real water resistance while allowing 1% air circulation within the fabric to greatly enhance moisture transport by convection. Power Shield Pro fabric is featured in softshell garments being introduced this spring by several manufacturers.
NeoShell is basically the Polartec Power Shield Pro membrane with air permeability reduced from about 5 cubic feet per minute to 0.5 cfm to increase its hydrostatic head enough to make it functionally waterproof, about 10,000 mm, which Polartec claims is sufficient. The 0.5 cfm air permeability of NeoShell, compared to zero for Gore-Tex and 0.1 cfm for eVent, enables enhanced moisture transport by convection in addition to vapor diffusion, justifying Polartec’s claim that “NeoShell is the most breathable waterproof fabric available on the market today” (actually starting in fall 2011).
Polartec NeoShell fabric construction (left). Rab Stretch Neo Jacket (right, 17 oz/482 g, US$365, available fall 2011).
Performance test data for Polartec NeoShell compared to Gore-Tex (aka “Leading Competitor Waterproof/Breathable”) and eVent (aka “Other Waterproof/Breathable”). Information provided by Polartec.
According to Polartec, the NeoShell membrane is a sub-micron fiber polyurethane membrane, rather than ePTFE, that is air permeable. That’s about all we know about the membrane so far, as details come out and we have more actual user experiences (including our own), we will have a much better description and impression of NeoShell and whether substantial performance differences really exist.
Polartec will launch NeoShell garments in fall 2011 with selected partners including 66 North, Eider, Mammut, Marmot, Mountain Equipment, Montura, Rab, The North Face, Vaude, and Westcomb.
Like Polartec, Columbia is reluctant to release the technical details of the membrane itself, and prefers to place emphasis on its performance. We did find out that Columbia found the membrane pre-existing in the filtration industry, it’s a “modified density polyethylene,” weighs 7 g/m2, it’s stretchy and strong, it’s 75% lighter than Gore-Tex and 50% air, and will withstand 20,000 pounds of water pressure. Woody Blackford, Columbia vice president for global innovation, explained the numerous lab tests they performed to compare Omni Dry to Gore-Tex and other membranes. I won’t repeat it all here, but suffice it to say that based on their testing, Columbia claims their Omni-Dry membrane is “the lightest membrane in the industry,” has equivalent waterproofness to Gore-Tex, and is “about as air-permeable as eVent and DryQ.”
Columbia graph showing Omni-Dry’s air permeability compared to Gore-Tex (left). Columbia Peak To Peak Jacket (right, 15.9 oz/451 g for size large, US$350, available spring 2011).
Omni-Dry will be offered in three garments to be introduced in spring 2011, and should not be confused with Omni-Tech, a polyurethane laminate, which is Columbia’s first waterproof-breathable technology introduced in 2008.
Mountain Hardwear DryQ
Also entering the fray is Mountain Hardwear (owned by Columbia) with their announcement of DryQ, which is based on an ePTFE membrane that is touted to have air permeability. It should, because Mountain Hardwear dropped their partnership with Gore, then partnered with GE Energy, the General Electric subsidiary that makes eVent. The company cites “the unique combination of the eVent membrane plus supreme quality face fabrics, barriers, backers, glues, tapes, and lamination technology to build its DryQ shell line.” Thus it appears that Mountain Hardwear was first in line, and the first OEM eVent fabric will arrive in fall 2011 under the name DryQ.
Mountain Hardwear Effusion Hooded Jacket (12 ounces/333 g, US$200) which is a minimalist stretch shell in Mountain Hardwear’s DryQ Active line.
There will be three types of DryQ: DryQ Elite for hardcore mountaineering and skiing, DryQ Active for lightweight high energy pursuits, and DryQ Core for the mainstream consumer.
Other Rumored Developments
When we visited the Pertex booth, a Pertex technology representative casually mentioned that Pertex is partnering with GE Energy and is developing appropriate Pertex fabrics to mate with the eVent membrane, and the resulting fabric will be called Pertex Shield DV (for Direct Venting). That sounds pretty definite since they already have it named! From our perspective, the fabric constructions from Pertex are likely to be the lightest ones available, so they may be the center of our attention. We looked at numerous NeoShell and Active Shell jackets at this Outdoor Retailer Winter 2011 show, and none of them were really lightweight. That’s because mainstream manufacturers perceive that consumers of high-end shells want them to be durable and full-featured. It will take awhile for the likes of GoLite, Montane, Integral Designs, and others to integrate these new technologies into truly lightweight garments.
GE Energy is also working on two new membrane technologies, which will be variations on their standard eVent membrane, possibly to be introduced in 2012. This could be something like an “enhanced air permeability eVent” in response to Polartec’s NeoShell. Whatever it turns out to be, it will surely create some excitement in the outdoor industry.
What This All Means
Some common threads in this synopsis are:
- All of the new and revitalized competitors developing waterproof-breathable fabric constructions incorporate membranes that provide air permeability, which they perceive is key to providing true breathability.
- They are all ganging up on Gore-Tex, perhaps in an undeclared effort to bring down the “Holy Grail” of waterproof-breathable garments, and gain market share by educating consumers on the advantages of air permeability to convince them that the technology is advancing beyond traditional Gore-Tex.
- Don’t think for a minute that Gore will take the competition lying down. They have already introduced Active Shell, and at the very least we expect the competition to heat up and get more interesting.
- We will soon be evaluating breathable membranes that are based on ePTFE (Gore-Tex, eVent, Mountain Hardwear), polyurethane (Polartec), and polyethylene (Columbia). At this early stage we are lacking information to understand their anatomy and how they work, but that information will be forthcoming for your reading enjoyment.
- We can expect this revolution to become more interesting and confusing as more and more membrane variations, fabric constructions, and proprietary branding are thrown into the equation.
- After many years of living with the status quo, it is indeed refreshing to see technology innovation in this category once again, and hopefully it will lead to some really exciting new products for us to report on.
The Bottom Line for Backpackers
All this said, it’s important to point out that the easiest way to improve moisture venting in a hardshell jacket is to simply open the front zipper, and open the pit zips if the jacket has them - simple convection to the rescue! For backpackers who carry a backpack over a hardshell jacket, be mindful that the pack covers a large portion of the jacket’s backside, the hipbelt seals the bottom of the jacket, and the shoulder straps compress areas of the frontside. That eliminates a lot of the jacket’s surface area for moisture venting, or as eVent would say “getting the sweat out.” Opening the front zipper helps a lot, plain and simple.
I have not yet met a hardshell jacket that does not steam up while I’m hiking uphill carrying a backpack. When it’s raining we have no choice, and it becomes a matter of adjusting undergarments and opening vents to attain comfort. Any increase in fabric air permeability would definitely be an improvement.
Given the constraints to a hardshell jacket’s breathability from wearing a backpack, we really do need hardshells designed with enhanced air permeability for high exertion pursuits. The question is, will enhanced air permeability of the jacket’s fabric produce any actual improvement in comfort under these conditions? Lab testing and breathability numbers, based on the same test methods, will eventually help to compare and differentiate the technologies, but perhaps the bottom line will be actual field testing while carrying a backpack to determine if significant and perceivable differences actually exist. Or, conversely, does it really make sense to purchase an expensive waterproof-breathable jacket and then wear a backpack over it? Backpacking Light hopes to test these new technologies very pragmatically in the months ahead and report findings to our members.
An index to the articles in this series:
An Emerging Revolution in Waterproof-Breathable Fabric Technologies - It’s Not Just Gore-Tex Versus eVent Anymore! (this article) Provides a description of the new technologies and highlights new jackets in the pipeline utilizing the new fabrics.
Field Testing Air Permeable Waterproof-Breathable Fabric Technologies Part 2: Are There Detectable Differences Under Real World Backpacking Conditions? Describes my testing method and presents field test results.
Field Testing Air Permeable Waterproof-Breathable Fabric Technologies Part 3: Discussion, Conclusions, and Performance of Individual Jackets Summarizes my findings and pragmatic conclusions from field testing the jackets while carrying a backpack, and discusses the pros and cons of investing in a high-end waterproof-breathable jacket. Presents test data for each jacket compared to “traditional Gore-Tex,” plus my comments on the most appropriate uses for each jacket.