Lab Test – Zpacks Waterproof Breathable Event Fabric

[Richard Nisley]

After a 1 1/2 month adventure trip I returned yesterday to find the WPB Cuben I ordered from Zpacks in my mail. Out of curiosity, I tested it even before even unpacking.

The executive summary is that my lab tests show air permeability is poor (on par with low cost micro-porous PU coatings averaging .17 CFM) versus 3 layer eVent (averaging .53 CFM for UL 3 layer jackets). See http://www.prolitegear.com/site/nw-alpine-eyebright-jacket-overview.html for a bubbler test comparison.

The WPB Cuben abrasion resistance is projected to be lower than 3 layer eVent because there is not a tricot layer on either side. See my eVent and 2011 version WPB Cuben micrographs in submission 45 – 47 shown at http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=45026&disable_pagination=1 .

My tests and micrographs suggest to me (not proves) that the 2013 dotted WPB Cuben uses MP PU forced through one side of the Dyneema fibers and then scraped (mechanically abraded) into a square pattern on the forcing side, rather than eVent membranes on two sides. An alternative explanation is that after lamination, they mechanically abraded the eVent membranes to have a checkerboard pattern with the double thickness membranes only remaining on the perimeters of the abraded areas. In either case, the fabrication methodology looks very similar to 2011 submission 47 using non-MP PU.

The areal density of the sample I tested was 58.14 g/m2 (1.71 oz/yd2). The areal density spec is (48.3 g/m²) 1.42 oz/yd2. The HH tested greater than 3,515 mm H2O.

The following micrographs list the field of view (horizontal distance) and illumination source (top of sample or bottom of sample).

1 – 20mm Bottom
This micrograph best illustrates the fabrication sandwich which is made up of two WPB layers each with a thickness of .027 mm sandwiched on either side of a Dyneema matrix-like-pattern with a thickness of .021mm. I measured the thickness of each layer in my lab. The major grids are formed from a thicker WPB material rather than thicker Dyneema fibers.

1 – 20mm Top.1
This view looks very similar to the 2011 submission 47 micrograph clearly showing mechanical abrasion after lamination.

1 – 20mm Top
The manufacturing abrasion patterns are not the same on both sides of the fabric. This is the side opposite of what is shown in the prior micrograph. Note there is no tricot layer to protect the WPB layer on either side from field use abrasion as is commonly provided with conventional eVent fabrications.

2 -5.0mm Bottom

2 -5.0mm Top

3- 1.4mm Bottom

3- 1.4mm Top

[Anonymous]

Thank you for the report Richard. If i had bought some of this gear, i might be a little bummed with these results. That level of breathability is nothing to write home about.

Do you think anyone will ever do anything with pure UHMWPE fiber fabrics? Or are there inherent limitations with using this fiber in a woven forms? I've read that the fibers are so slippery that they do not stay put well in a weave or knit form, BUT i have some 100% woven dyneema sleeves which are holding up just fine… so i'm not sure what to believe.

[Stephen M]

Hi Richard,

Hope you had a great trip.

Much appreciate you testing this.

Cheers,

Stephen

Hey Richard,

Very much enjoyed this – huge thanks for taking the time (and spending the money) to do this. Love it when the community comes together to really investigate these kind of things.

I updated my original article on this fabric to include a link to this page here at BPL.

If you would be up for sharing a paragraph or two and maybe a photograph within my article drop me a PM.

Again, thanks!

+John Abela

ps… really quickly… would like to address/bounce this one thing off you…

I think the really interesting part of this was the statement:

the fabrication sandwich which is made up of two WPB layers {eVENT} each with a thickness of .027 mm sandwiched between a Dyneema

As I read it, you are saying that it is two layers of eVENT INSIDE of a spliced-open piece of Dyneema (thus-three layer… it would be four layers if the Dyneema were literally on both sides and the Dyneema was not spliced-open, right?)… anyway…

that goes against all we have been told about this fabric… as Joe has written on the zpacks website, and been told by CTC:

the fabric is a three layer laminate with high strength Dyneema fibers sandwiched between eVent

So… that has my head spinning in two different directions…

CTC is saying it is: "eVENT -> Dyneema <- eVENT"

You seem to be saying it is: "Dyneema -> eVENT | eVENT <- Dyneema" (thus, "two WPB layers… sandwiched between a Dyneema")

Looking for clarification on this Richard. Maybe I just mis-read what you are saying (???) Thanks.

[Richard Nisley]

John,

I was incorrect when I said, "the fabrication sandwich which is made up of two WPB layers {eVENT} each with a thickness of .027 mm sandwiched between a Dyneema" I will update the original post. The Dyneema is in the middle.

[Ryan Smith]

Big thanks Richard.

Ryan

[Ben C]

Thanks loads, Richard, for providing this information to the community. Its really helpful.

[Sam Farrington]

Thanks, Richard. You da' man.
BTW, thought you were an individual, not a community. Are you from Earth?

[steven franchuk]

richard, Thanks for doing this test. It confirms what I was expecting.

I have a westcomb specter Lt Event jacket. The pockets in this jacket were made by stitching two pieces of Event fabric together. This portion of my jacket is the only location where condensation has occured in my earlier testing (It has been very dry in California since then so it hasn't gotten much use on the trail}. Unzipping the pockets helps but 2 layers of Event is not nearly as good as a single layer.

Two layers means:
1 It takes longer for air to work its way through meaning less moisture is carried away.
2. Zpacks must use some sort of glue to bond the two layers of Event membrane to the fabric in the middle. The glue can cover some of the microscopic holes in the membrane further reducing breath ability.

Zpacks would have done better it the cuben was one the outside with one layer of Event membrane was on the inside surface.

Zpacks must use some sort of glue to bond the two layers of Event membrane to the fabric in the middle … Zpacks would have done better it the cuben was one the outside with one layer of Event membrane was on the inside surface.

Uhh, ZPacks has nothing to do with fabric manufacturing. No more than NW Alpine does with their jacket that uses this same fabric. These two companies just make the garments with the fabric that CTC supplies them.

[Woubeir (from Europe)]

I wonder if eVent DVL could then be a solution to give better results: Cuben + eVent + DVL print ?

[Tom Beno]

Your empirical evidence supports the less scientific "bubbler" test that Prolitegear did – this new fabric is excellent from a weight standpoint but its breathability is not impressive. Too bad, but just what I was afraid of.

[Rick M]

del

[M B]

Great info and much appreciated.
The jacket doesnt seem to be what many are looking for, at least not at $250.

[spelt with a t]

So it seems the breathability claims are much overstated. Shame, this was on my shortlist. By the time I get around to purchasing a new rain jacket, though, they'll probably be on 3rd gen fabric.

[Woubeir (from Europe)]

Of course, Richard tested the AP and not the MVTR and perhaps 5 years ago an AP of 0,17 CFM was deemed good to very good (as nearly all WPB-materials had a cfm of 0).

[Anonymous]

"Of course, Richard tested the AP and not the MVTR and perhaps 5 years ago an AP of 0,17 CFM was deemed good to very good (as nearly all WPB-materials had a cfm of 0)."

I'm a bit confused, since Richard said this earlier.

"The executive summary is that my lab tests show air permeability is poor (on par with low cost micro-porous PU coatings averaging .17 CFM) versus 3 layer eVent (averaging .53 CFM for UL 3 layer jackets)."

My confusion stems from this–my understanding is that low cost micro porous PU coatings have been around for awhile, and have been considered "poor" in the breath-ability/air permeability department for awhile.

Then, comparing that to average 3 layer UL eVent material, by the numbers it seems that these are roughly 3 times more air permeable than the cuben-eVent and the PU stuff, which in my mind is a considerable difference.

Or isn't it?

[Greg Mihalik]

"Then, comparing that to average 3 layer UL eVent material, by the numbers it seems that these are roughly 3 times more air permeable than the cuben-eVent and the PU stuff, which in my mind is a considerable difference."

I must be low on caffeine …

Please re-state your question.

[Anonymous]

"I must be low on caffeine …

Please re-state your question."

3 X .17 = .51 ~= .53?

[Anonymous]

Hi Greg et al.

It was less a specific question and more pointing out a seeming conflict between Richard's earlier post and Tom's latter post.

That may have been a misconception on my part.

In any case, i would say 3 times air permeability of non cuben, 3 layer eVent compared to the cuben version, is pretty significant. Even if it was only 2x, it would be pretty significant in my book.

But design of the actual jackets would be pretty important too, with large pit zips, the cuben eVent could be fairly good. But is it worth the money?

[Ken Larson]

I have a ZPacks Rain Jacket …… 1.42 oz/sqyd Waterproof Breathable Cuben Fiber material (Original prior to August 2013 "NEW" material) now for over three years. It has experiences MANY forms of moisture (rain, sleet, snow, fog)in the Mid West Region of the USA WITHOUT issues. This ZPacks Jacket is my design. The jacket is designed with fourteen inch pit zips AND the eleven inch neck zip that I feel provides the "breathability" and adaptability at a minor weight "cost". How this jacket would perform without the neck and pit zip features is an unknown…..unless Joe V has receive feedback he would share with you all.

Joe's WPG Jacket Review (after Te Araroa Trail in New Zealand Adventure) with a "STOCK JACKET" will give you insight to the breathability issues that have been talked about in this thread…..
"I personally thought the breathability of the jacket was quite good. As long as the temperature stayed below 60F (15C) I was comfortable and stayed dry from sweat. In warmer weather it was too hot to hike in any jacket, so of course I did sweat some. The jacket was also comfortable to wear as a wind shirt, or to sleep in, as long as the outside temperature was appropriate.

Sheryl sweats more than I do. I would say her comfort zone was probably more like 50F (10C). Above that and she would get a little damp from perspiration. This was especially evident under her belt, shoulder straps, and sternum strap where the moisture could not escape. I don't think this was any fault of the jacket, any warm shirt or jacket has the same effect on her.

Neither of us had any issues with rain getting in from the outside. The material is waterproof, and I stayed completely dry as long as the temperature was cool.

Neither of us had the Armpit Zips option. I never missed them, but Sheryl wished she had them for venting."

AND I would like to conclude and concure with John Albela's Final Thoughts noted his review (http://hikelighter.com/2012/01/15/zpacks-waterproof-breathable-cuben-fiber-rain-jacket/ ) of the jacket: "If you live in a region where there is non-stop rain you need to consider whether you are able to control your own thermoregulation or if you need help from a high level breathable jacket to help you do so – at the expense of double or triple the weight. As somebody who lives in a rain forest, I highly recommend if you do as well, to order yours with pit-zips to help with some air circulation – an additional 11 grams is a small weight penalty for the advantage of having the ability to offset the low breathability of the material to help you maintain a constant peripheral temperature."

[Greg Mihalik]

There are a lot of options out there, including custom builds.

My Thru Hiker eVent jacket died and I was ready to pull the trigger on this jacket. But the message here is that this jacket does not have the air permeability I expect from eVent. Not even close.

I imagine any W/B PU jacket with pit-zips would do almost as well.

The search continues.

[Woubeir (from Europe)]

Actually, there is no conflict. Richard tested only the AP which is indeed less then a thirs of earlier regular eVent-measurements, but should be more or less equal to Breeze Dry-tec from Montbell. There's also the MTVR (or whatever some are calling it) and that is claimed to be high with more then 40.000 g/m2/24hr. And for the overall breathability both AP and MVTR need to be taken into account.

Venting is of course an extra element and because everybody is different, some say they don't need it at all, and others say they absolutely need it.

[Stephen Collins]

FWIW I have a zpacks jacket with the latest material and it seems pretty darn breathable to me.

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