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GORE-TEX 101

Gore-Tex, we’ve all heard of it, but what exactly is it, and do we really need it?  It has become almost a generic term for a line of advanced technology fabric systems, that when it comes to ski jackets and pants, is one reason why “shells” are now so popular. Because of materials like Gore-Tex, layering, or the ability to add or shed inner layers, translates to all day comfort. Since the outer shell is your first line of defense, it only makes sense to choose something that will not only keep you warm, but also cool. Thankfully, some relatively new high-tech fabrics known as microporous membranes provide just the solution.

 

 

Gore-Tex is the original and most established brand of microporous membrane fabrics. Since its patent ran out, there are now a slew of imitators, but the term Gore-Tex has become almost a generic term for all these MMFs. So whether it’s eVent, Intuitive, H2NO, HyVent, Polartec NeoShell, or others, they all share variations of the same basic technology providing a breathable, waterproof, and windproof fabric.

 

The Membrane: The PTFE membrane is the heart of all Gore-Tex products. It contains over 9 billion microscopic pores per square inch. These pores are thousands of times smaller than a water droplet, yet thousands of times larger than a water vapor molecule. This makes the membrane waterproof from the outside, while allowing perspiration to escape from the inside.

 

These fabrics come in varying degrees of waterproofness & breathability effectiveness. This is expressed in terms of how many millimeters of water in a 1" column a fabric can repel before it starts to leak and by how many grams of water vapor can escape over a 24-hour period. The best fabrics are generally rated around 20,000mm/20,000g which would be expressed as “20k/20k”.

 

The Laminate: The laminate is the membrane bonded with the main body synthetic fabric. It is laminated to either one or two surfaces, being described as two or three-ply (2L or 3L). Three-ply is warmer and more durable, while two-ply is softer and lighter.

 

The terms hard shell and soft shell, when referring to outerwear, are just as they sound. It is how they feel to the touch and may or may not be MMF fabrics. In the case of Gore-Tex, the softer feeling fabrics would likely be 2L (possibly 3L), while the stiffer fabrics are 3L. In a serious mountain/backcountry shop, a soft shell does not have a membrane (is not waterproof) and a Gore style soft shell is now referred to as a "stretch hardshell".

 

Sealed Seams: Sealed seams are used to offer complete weatherproofing. A special tape system is used to seal off the holes created when the garment has been stitched during manufacturing.

 

Durable Water Repellent (DWR): Gore-Tex fabrics designed for use in the outdoors are also coated with a surface treatment at the final stage of manufacturing. This DWR treatment is used to keep the breathable pore based fabric free from beads of moisture and rain, allowing them to fall away.

 

The DWR typically has a shorter life span, so while the pore construction of the fabric is still working, you may notice leaks and seeping of moisture. When the face fabric eventually becomes soaked due to an absence of DWR, there is no breathability and sweat will cause condensation to form inside the jacket. This may give the appearance that a jacket is leaking when it is not. The DWR can be reinvigorated by tumble drying the garment, ironing on a low setting, or you may need to retreat the item in order to reestablish its water repellency. To retreat a Gore-Tex product, simply wash it and then apply a reproofer, which can be a wash-in or spray-on product. NikWax makes a nice line of such products.

 

The outdoor fabric industry is currently experiencing a surge in new product development that competes directly with GORE-TEX®.The technology of these fabrics continues to advance and not all of the waterproof breathable laminates on the market are built like GoreTex. In fact, most of them are built differently. Some share the ePTFE membane element and some go with the solid polyU membrane.  Products like eVent™, Polartec® Neoshell®, Omni-Tech, Conduit, and Dri.Q Elite are all extremely waterproof and push the envelope on breathability. Use of very thin Polyurethane and Polyester membranes is also expanding, with much of the innovation coming from Asia – these fabrics have the advantage of not requiring a separate layer to protect the ePTFE membrane from contamination, and are catching up in the breathability department.

 

 

   Examples of Waterproof/Breathabilty Ratings for some of the major manufacturers:         

Brand

Fabric

Waterproofness (mm/24)

Breathability (gr /24)

Columbia Sportswear

Omni-Tech®

10,000

10,000

Flylow Gear

Intuitive 3-Layer

20,000

20,000

Event

Event

30,000

22,000

Gore-Tex®

PacLite®

28,000

15,000

Gore-Tex®

Pro-Shell 2-Layer

28,000

25,000

Gore-Tex®

Pro-Shell 3-Layer

28,000

25,000

Lowe Alpine

Triple Point 3-L

20,000

20,000

Marmot

MemBrain®

20,000

25,000

Marmot

PreCip®

15,000

12,000

Marmot

PreCip Plus®

25,000

15,000

Mountain Hardwear

Conduit

20,000

20,000

Sierra Designs

Hurricane

8,000

2,000

 Examples of Waterproof Breathability Ratings for Major ManufacturersExamples of Waterproof Breathability Ratings for Major ManufacturersExamples of Waterproof Breathability Ratings for Major Manufacturers   

 

 

As you can see, the technology is quite complex and there are many different variations and approaches to achieving a high performance microporous membrane fabric. Add to this the fact that testing is generally done independently and lacks any real standardization. Also many other factors involving how different materials interact in combination with one another will have a dramatic effect on the true and perceived overall performance of any given MMF garment.

 

 

So what should you choose? Given performance versus price, what do you really need? Generally speaking, most resort skiers would find garments with a 10k/10k, 2L fabric more than sufficient and reasonably priced, while the more serious demands of backcountry riding may warrant the additional expense of a 3L, 20k/20k offering. Unfortunately, not all manufacturers explicitly provide these specifics on the label, but any good shop should be able to provide them, and you should know what you are paying for. So stick with a reputable brand, ask questions, and check product reviews on great resources like EpicSki's Gear Reviews.

 

 


 

Comments (5)

Great Info, Thanx
Cool, but I think limiting the conversation to Gore-Tex is shortsighted. There are just so many other options out there that may lack the marketing power/Brand name recognition of Gore. I think Blister covers it real well in these 2 articles.
http://blistergearreview.com/articles/outerwear-101
http://blistergearreview.com/recommended/outerwear-201-marketing-wars-new-technologies-paradigm-shifts
Thanks. Thought I was pretty clear to point out that the term Gore-Tex, which to many is all they've ever heard of, was only being used generically and why that is.
There are many sources on the web that go into far greater detail than this article, and it was from those that I tried to condense into something short and concise and hold the attention of the casual reader. 101
This was sent to me from Dan Abrams at Flylow Gear before I hopefully edited out most of the inaccuracies. He adds some interesting history and info...
Hey John, this is good read and as a fabric dork myself it is good to see someone trying to educate their people.
There are a couple of inaccuracies, but for the most part it is pretty darn spot on. The conversation on soft shells is is an interesting one. The traditional soft shell is actually a scheoller (a swiss fabric mill) product that uses tightly woven nylon and lycra to create a water and wind resistant layer. This is what all ski gear form the 70's was made from and even in to the early 80's in the form of racing stretch pants, speed suits and tight stretch pants for women. In the 90's Clouviel brought this fabric back a popularized it, but in a looser fit that was great for climbing and backcountry skiing. All companies began making gear for active customers with the schoeller fabric again. When Gore realized that they were loosing market share they lobbied the US congress to create an import duty of 32% to 38% on water resistant fabric without a membrane. Congress then passed an import duty of 7% on waterproof gear with a Gore type membrane. Then, Gore came out with a soft to touch and stretch feeling 3L or 2L fabric and labelled it "soft shell" as well.Moving forward, the coolest new fabrics are what we call "air permeable waterproof breathables". At the forefront of this technology is Polartec and their new Neoshell fabric.This is the most breathable waterproof membrane on the planet, and guess who is the only American ski clothing company using this most high tech fabric in their clothing? Yep, Flylow. The new Lab coat and Compound pants just won the Polartec APEX award and will be sure to collect some more this season.D
As a Cloudveil user for many seasons I can attest to the Koven jacket and pant's ability to breathe. On cooler days when not working hard enough they can breathe too much. Takes a little getting use to.
The Cloudveil jacket makes a great rain shell here in Florida, where my Arcteryx ski shells just don't breathe enough.
The Koven gear stays home during the winter months and is used mainly for sunny spring days or touring.
Where as my Gore-Tex gear is my go-to gear in all other winter elements.
Also used hy-vent for several seasons as a spring shell, but it is clammy as a rain shell in Florida, but is packable.
I have the advantage of opposite climates which is a great way to test these fabrics.
My name is Al, and I am a shell junky. ;-)
Solid article. kudos
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