WPB direct venting cuben?

Event is currently protected by patents. That means no one can make eVent fabric except eVent or anyone they license. These patents will proably expire in about 15 to 20 years. Once the patents expire anyone can make fabric using eVent technology. Gortex was invented in the 70S and most of their original patents have expired.

Cuben VPB fabric is white and reportably has a waxy feal. Both indicate WPB Cuben is using a PTFE membrane like Gortex (expanded PTFE with a polyurethane layer) and Event (modified expanded PTFE membrane). While it is possible they came out with there own PTFE membrain and patent I haven't seen anything indicating they did that. In all likelyhood they just purchased a generic PTFE membrane (probably a generic copy of a early version of Gortex)and replaced the two plastic layers in standard cuben with two layer of the PTFE membrane.

Event has a breathability rating of 20,000 to 30,000 gsmhr (depending on the test method used. http://WWW.Suluk46.com list caben WPB at 1100 gsmhr. That is the lowest rating of any WPB fabric I have seen. Did they miss a zero in the article? 11,000 would make more sense which would make it about average for all WPB fabrics. they don't list the measurement method so I cannot say for certain how it compares with eVent.

I don't own a Cuben WPB jacket but from what I have sen I am currently not planning on buying one to replace my eVent jacket.

where is steve from suluk…I'll try to ping him.

So essentially what you are saying is:
No one can do direct venting PTFE like eVent …that is sad. I wonder if anyone can find a workaround for the patent.

the MVTR of the cuben is basically zero. @nisely had some figures correlating MET with MVTR which i cant find right now but this is really low.

Is it even worth it? why should I pay mega $$ for this low breathability when I can get a chep silnyl jkt???

Mike

Hey Mike,

I would say I am up there with a very small handful of other hikers with a lot of usage of the WPBCF and like most of the other guys that have been really putting it to use I have found that it has some very good points and some not so good points to it.

An important thing to remember is that Cuben Tech is only in its second or third revision of this WPBCF so it is still years behind eVENT and decades behind GT. This most recent version (the version that companies such as zpacks and black rock gear are using) is a serious improvement over their last version. To think that in the next year or two Cuben Tech is just going to continue to improve on this material should not be to unrealistic.

I am not able to share hard numbers but what I can share is that the testing that I have seen places this latest version of the WPBCF at around 1/3rd the breathability of the most recent revision of the eVENT material. Try to to compare it to the latest revision of the light weight GT would not even be fair… it is no where near ready to be compared to it at this point.

Here is what I can say from personal experience with the WPBCF over the last 13 months that I have been using it.

Durability has been very good. It does discolor as you use it into a odd shade of black. I documented this in my initial followup article on the zpacks wpbcf rain jacket. You can see the original article at this page.

It is one of the softest materials that I have (compared to eVENT, GT, SilNylon, etc) and I have slept in my jacket a lot (probably 30+ nights) and I have recently been sleeping in the pants and find them to be just as comfortable.

But lets talk about what really matters… does it keep you dry. The answer to that is yes.

But let us be honest, the really really big question is does it breath? Well, compared to eVENT or GT, yes it does breath, but no where near as good as either of those materials. To be honest I do not think it will ever be able to get up there to where eVENT is at… I am just not sure it is possible. Cuben Tech might someday pull some mysterious layering system together, but I just do not see it happening.

What then does going with the WPBCF have over eVENT? Well that is simple: Weight. I have yet to see any eVENT jacket in the sub 200 gram range. Both of the ZPacks WPBCF jackets I have bought have been 135 grams. I am just not sure anything out there in the eVENT world has been able to reach this limit. (not saying something has not, I just do not know of anything that has).

I think these two paragraphs (from my followup article) sort of summarize the theory/reasoning of going with a slightly heavier eVENT jacket, or the slightly lighter weight WPBCF rain jacket:

Over 90% of hikers do not hike a 500 miles a year. Of the remaining 10% less than half of them do over 2000 miles a year … As most tripple crowner can testify too, the use of rain gear on the big-three trails is typically less than 2% of the 8000+ miles. You really going to be wearing your *rain jacket* for 2600 miles? Stop and think about that.

So with this in mind we need to ask ourselves, is the weight of a 10+ ounces rain jacket really worth carrying? I say no. If I can hike any of the long distance trails in the USA and typically encounter less than 20 days of rain, why would I carry twice the amount of dead weight when I need too. For me, being able to save 5 ounces off a largely dead-weight item such as a rain jacket is an amazingly exciting aspect.

Still, there is something to say about actually carrying those additional five or more ounces for a rain jacket that is far and above the breathability count of what the present Cuben Tech WPB cuben fiber is. If you are one of those hikers in a situation where that is warranted it should be a no-brainer to go with eVENT or GT over the lighter weight WPBCF.

–Abela

@Abela

thanks for the input.

when you say "i cannot share" are you talking about technical testing you yourself did? if so why not share…?
If you are saying the company will not share data with the public – that is lame on their part.

RE weight – Montane minimus smock is reportedly 143g….indeed only Pertex Shield+ but that is getting close to the WPBCF….
No doubt if i were doing some alpinism (full day vertical ice climbing etc) or similar that warranted a tough shell i would not think twice…but for my LW backpacking stuff where I indeed end up wearing the shell maybe 10% of the time its a big Q….
many good jackets these days are starting to push towards the 200g limit (westcomb eVent DVL etc) and they still seem more abrasion resistant and the WPBCF have no pockets or sculptured hoods so its not a fair comparision. I assume with a real hood a single pocket, real cuffs and hem etc they would end up 5+oz….

M

@Mike, regarding data… I have been given test results from three different companies non affiliated with any of the material manufacturer and they all are saying pretty much the same numbers. I cannot share the test results because I am just not able to share the results. This sucks but I value my relationships with the industry too much to violate their trust. I keep hoping that one of them steps forward and releases a whitepaper to the public. There are a few guys on here at BPL that have the ability to perform similar tests on this material, perhaps you could ask one of them if they have done any such tests and if they would be willing to share those tests in the form of a whitepaper.

Totally agree that the Minimus Smock is one of the biggest competitors out there! I, sadly, have yet to get into one. Its MVTR is impressive (as stated above, the WPBCF is only one-third, at its best, as good based on the breathabilty reports I have seen). Its weight is just insane. At ~145 grams, and its MVTR, and if it can come in below the $200 mark, and actually proof to handle hours and hours of constant rain without failing (I have over 6 hours of straight use in the ZPacks WPBCF rain jacket and it had not failed to saturate through) then there will be little reason to go with the WPBCF rain gear that is out there. It will simply be at a point where its price point to weight ratio to breathability levels are such that it would be totally illogical to buy anything else except in all but the worst of rain conditions. The perfect triune of weight, price and performance. If it actually proves itself, it could totally dominate the market I think.

Michael,

Re: "Is it even worth it? why should I pay mega $$ for this low breathability when I can get a chep silnyl jkt???

First, one of the threads with Richard's test results is at:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=45026&skip_to_post=396949

Posts on that thread also note that the WPB treatment on the CT product is Polyurethane-based. This is a common treatment found on many so called "2.5" layer products that vary in quality from cheapos on Campmor to some pretty good products that have been made by Patagonia. I luv my Specter.

But it is not in the same category as Event, or even DryDucks, for breathability, or vapor permeability.
Please read Alan Dixon's article on BPL to get a handle on this:
http://www.backpackinglight.com/cgi-bin/backpackinglight/00316.html?id=6Zrz4Ymg&mv_pc=2282
There are graphs and charts in the article that show the respective merits and weaknesses of the different types of WPB materials.

But in comparing silnylon to any of these, your question above suggests you are not aware of how well the urethane treatments do function. They are a heck of a lot better than a vapor barrier such as silnylon.

But if you ask why should you pay a lot for a WPB Cuben jacket when you can get a much cheaper one, the answers are: Strength, extremely light weight, and snob appeal.
High quality nylon, like Dupont 6.6, is plenty strong for a jacket, so zero on that.
And there are a number of very light weight WPB nylon jackets, so zero on that.
In fairness though, some of those very light nylon jackets breath quite poorly. Still, some others are quite good. Read the reviews on this site. Unless you are trying to get all that info just from a forum membership. Sorry, not gonna happen.

So that leaves snob appeal. Yah!

P.S. On the info sharing issue, Cubic Tech in the past has required all its customers to first sign nondisclosure agreements that read like they might have been prepared by lawyers for the CIA. So many are a little reluctant to open up.

"No one can do direct venting PTFE like eVent …that is sad. I wonder if anyone can find a workaround for the patent."

I haven't read the Event patents put I believe the term "direct venting" is just marketing to help people understand unlike most WPB fabrics air can flow through the eVent fabric. Patents typically cover the construction of a material not a phrase such as "direct venting".

There is one other fabric that can be described as "Direct Venting", Polartec NeoShell. Like eVent air can flow through the membrane unlike most other WPB polyurethane Membranes. But unlike eVent the NeoShell membrane uses Polyurethane in its membrane. The NeoShell membrane is also manufactured very differntly from other WPB fabrics and has a very different microscopic structure than other polyurethane WPB fabrics.