This is a review of a new fabric from GORE-TEX, through the vehicle of a basic tester jacket that is designed to showcase the fabric. If you want to see how the fabric performs and don’t care about the background, skip ahead!
Background: why shell jackets matter
If you are someone who loves to live and play outside, you probably care about the impact of human industry on the environment. We’ve known for years that one of the mainstays of our gear, the waterproof jacket, poses a serious environmental concern. Industry leaders from Gore to Patagonia to Arc’teryx and REI have all joined the EPA in raising the alarm about the role of a diverse group of chemicals known as polyfluoroalkyl substances (PFAS).
These ‘forever chemicals’ are implicated in a wide array of health impacts ranging from developmental delay in children, immune dysregulation, increased cancer risks and metabolic syndromes like hyperlipidemia and diabetes. This hit home in my community when dangerous levels of PFAS were found in wells adjacent to an Air Force base which used PFAS-containing firefighting chemicals.
What’s Gore got to do with it?
W.L. Gore has a long history of innovative products, stretching back to 1970 when their first fabric hit the market to make a miniature co-axial cable coating. Within 10 years, that product would be on the surface of the moon. Their fabrics circle around the idea of an expanded polymer, with membranes made out of polytetrafluoroethylene (PTFE) that was ‘yanked’ to create a microporous structure that was mainly (70%) composed of air. ePTFE, as it came to be known, formed the basis of the best waterproof/breathable membranes for years to come
GORE-TEX is well aware of the health concerns related to PFAS products. Their new fabric, an expanded polyethylene (ePE), applies the same concept of stretching a polymer to create an air-filled, porous membrane; the difference is that polyethylene is not one of those PFAS forever chemicals.
The ePE fabric sports half the material mass for garments, and one-third the material mass for gloves, as their traditional membranes. This means that, garment for garment, each piece manufactured with ePE fabric boasts a smaller carbon and material footprint, and a lighter impact on the world.
Currently, GORE-TEX’s other lines including GORE-TEX PRO, PACLITE and Active still use the old ePTFE fabric. They told me via email that they intend for their entire consumer line to use the ePE fabric by Winter 2025.
GORE-TEX ePE Fabric:
GORE-TEX sent me a sample jacket made out of the new ePE fabric. The jacket isn’t available for sale, and it’s not really meant to be: it’s a utilitarian, well-made but basic shell jacket meant to showcase the material. We’ve got two hand pockets, a two-way sealed zipper, adjustable hems and cuffs, two-way adjustable hood and pit zips. So it’s a full-featured test jacket which I was able to use skiing and biking, even though it’s just a platform to test the fabric.
I have repeatedly lamented how warm this winter was, but it made for great fabric testing. This jacket became my daily commuter as I biked to work, averaging about twelve miles a day in it. This is a great way to beat up a jacket, as the face fabric chafes beneath my messenger bag, I sweat, and it rains.
A lingering question that I have is whether the PFC-free fabrics still have the oleophobic properties of the old ones. Oleophobic properties are important on the interior surface of membranes because they repel our natural body oils. Body oils can degrade the integrity and performance of waterproof/breathable membranes. When I asked GORE about this specifically, they said: “Gore (and the GORE-TEX brand) does not disclose specifics about the chemical compositions of its products for intellectual property reasons.” So I can’t comment on this aspect of fabric durability. If you find out, let me know.
Why you still get wet:
It’s worth reviewing the common misconception about ‘wetting out’ a fabric. Most high-performing membranes are bonded to an outer nylon or polyester shell fabric and an inner liner to protect the membrane. The waterproof/breathable membrane is always waterproof; it doesn’t leak unless you have failure around seams, a hole, or it’s nearing the end of its useful life after many years of wear. The microscopic pores in the ePE fabric are smaller than a drop of rain water, but large enough for the water vapor made by a working body can escape.
People will often ‘wet out’ their waterproof/breathable jacket when the outer shell fabric saturates with water. This impairs the membrane’s ability to transmit vapor, and people get wet from the inside out from their own sweat. Maintaining the DWR on your shell is a separate topic. It’s critical to these high-performing shells where keeping them clean and refreshed yield performance dividends.
Trust the numbers:
The laboratory testing on the new ePE fabric tells the story. This fabric is so waterproof that a column of water 28 meters high set on top of the membrane will not leak through. This meets the industry standard for an absolutely waterproof fabric. On the breathability side, the independent laboratory Hohenstein grades fabrics based on their comfort. They give the ePE membrane their highest ‘very breathable’ comfort rating; this is the same industry standard that things like surgical gowns or hospital isolation suits are subjected to. This test measures how well a fabric can equilibrate a vapor pressure difference across the membrane. The fabric is also windproof, but that test is boring. All of these membranes feel essentially completely windproof.
The bottom line here is that this fabric meets the highest standards of the best GORE-TEX products. It should be functionally indistinguishable from their other top-line fabrics. Next let’s talk about some of the less tangible aspects of the fabric.
Where art meets science:
People often talk about the ‘feel’ of a fabric. They mean things like how plastic-y it feels, or whether it’s loud and crinkly like a potato chip bag. This relates to what the membrane is bonded to, so it can be tough to make direct comparisons. For instance, GORE-TEX’s C-Knit backer (reviewed on the Arc’teryx Sabre LT bibs) can be applied to most membranes to give a soft-to-the-touch handle. The tester showcases the ePE’s soft, quiet handle. It doesn’t rustle or have a plastic feel to it, even beneath the heavy duty 40D with 60D reinforced paneling on my test piece. This tester has the C-Knit backer, which might explain some of the gentle handle.
Gore’s new ePE membrane features:
- Leverages high strength-to-weight ratio to create extremely lightweight and thin composites that are still mechanically robust.
- Enables durable performance and a low environmental footprint.
- When combined with Polyurethane (PU), the result creates a durably waterproof, windproof and breathable membrane.
- Combination of the ePE material and low membrane mass results in a lower carbon footprint, as measured by Higg MSI.
- Advances Gore Fabrics Division’s goal for being free of PFCs of Environmental Concern over the lifecycle of its consumer products.
Learn More: Visit Gore-Tex.com
