UKH

Lots of new fabrics on the way, has Gore's patent expired?


http://www.adventure-journal.com/2010/11/guaranteed-to-make-you-buy-three-n...

There's some interesting (to me at least) stuff in this article about finding a compromise between windproofing and breathability, particularly in the comments section at the bottom.

In reply to Oceanic:

Physics isn't my strong point, but I've been thinking about the science behind Polartec Neoshell.

I guess what we call breathability is really closer to evaporation...

Non breathable waterproofs have the evaporated water condense on the inside of the fabric.

Goretex lets the heat build up until the water inside evaporates and is passed through the membrane. The rate of evaporation is slowed by the air inside becoming saturated.

Neoshell (and Event?) lets some air through so the air inside doesn't become saturated, therefore more evaporation can take place at a lower temperature.

Physics geeks please feel free to comment...

In reply to Oceanic: Not quite, Gore-tex has a thin layer of Polyurethane on the inside on the PTFE-membrane tyo protect it, so in reality, the moisture must first evaporate from your skin, condense on the PU, passthrough the PU and then evaporate and pass through the PTFE membrane.

In reply to Oceanic:
First, I've got to declare a bias: you may have seen FurTech clothing.
It's interesting to see that other manufacturers are talking about small amounts of airflow through the outer fabric, not just Polartech but Epic, which declares 3 times more breathability than normal hardshells. FurTech and Paramo outer fabrics allow some airflow, as do all woven windshell fabrics, even though you won't notice it.
The big difference between FurTech type systems and membrane barriers is that the latter block liquid water from getting out as well as getting in. This means that to get rid of any condensation inside (or stop it from forming in the first place) the membrane has to be above the dew point conditions (temperature, pressure and humidity). This is unlikely in cold wet conditions, especially if the outer fabric becomes saturated with rain which, in the UK, tends to start as snow in the upper atmosphere and is cold. On the other hand,in these conditions, FurTech outer fabrics switch from being water repellant to saturated (you can see them wet out; they have a "sentiment change"), which helps draw moisture from the lining and presents it to the outside air where it can dry when conditions change. In short, none-membrane fabrics dry quicker because there's no blocking membrane.
Additionally, you're unlikely to feel any condensation in FurTech clothing because the lining moves it away.
On the other hand, if you sit in a puddle in our trousers, you'll get wet. But they do defend against most stormy, wet weather.
Should you be a gluton for punishment there's much more on our blog at www.furtech.typepad.com
Cheers, Andy.

In reply to FurTech:


Assuming you mean Nextec EPIC, then it is, of course, a treatment applied to various base fabrics, rather than a fabric itself. It could even be applied to fabrics that have a membrane or waterproof coating (e.g. as used in Patagonia's defunct EnCapSil DWR items).

http://www.nextec.com/


Are you saying that the dew point falls within the thickness of the shell fabric itself, so that expelled water vapour condenses within the fabric, rather than the saturation that occurs when liquid water is applied externally (and, ideally, repelled by the DWR)? And since it's now wet, are you suggesting that the interstitial water will now pull condensed water from the reversed pile of the lining, by capillary action?

How does this saturation allow the garment to continue to breathe, given that there may now be a continuous film of water within the fabric? I'm guessing that passage of vapour from inside to outside (aka breathing) is now impeded. Do we have to evaporate the water from the saturated fabric before the fabric will breathe again?

Not saying that this is any different/better/worse than membraned garments, just trying to further my understanding of the behaviour of Analogy-type systems.

In reply to Oceanic:

im looking forward to checking out this neoshell stuff.

what has long interested me tho is whatever happened to INCITE?
mhw had it nailed 5 years ago with the stuff, brought out one or two products in it to rave reviews, then it dissappeared.
i keep wondering: is the latest offering just it renamed after a patent war? the stretch element stuff patagonia uses feels a lot like it.
maybe neoshell?

amazing stuff marketed as weather repellant mosquito mesh: stretchy, non-clammy, superlight in the mhw applications, as breathable it feels as any other high end textile (epic, proshell, conduit) and as water resistant as any other too....but it vanished.

asking mhw all i got was 'we couldnt make it in other colours' (it came in a steely grey). which sounds weird.

if anyone knows about the stuff, has even heard of it, let me in on it.
maybe, just maybe, neoshell etc is it reincarnated or even better, evolved.

In reply to ice.solo:
Stretch Element is Patagonias proprietary membrane H2NO, it is softer and stretchier than goretex but has the same crap "breathability". eVent improved the membrane game by having less fabric between you and the outside as well as bigger pores making it breathe better but it's still 100% windproof.
NeoShell is supposed to up the ante by doing a similar build to event but with stretch and more pores per sqm (correct me if I'm wrong here) and is 99.9% windproof. That 0.1% supposedly has a big impact as that tiny amount of air speeds up evaporation and moisture transport a great deal.
The problem is still Gore's giant marketing budget, which partly crushed event (which is superior to the stone age goretex membranes).
I hope Polartec succeed, it's time for gore to let someone push things forward.

In reply to Djupnes:


Well... eVent is a genuine gas permeable membrane (the pores in the ePTFE aren't blocked by a PU layer like they are with Gore-tex clothing fabrics). When Gore-tex was originally launched, it too was gas-permeable, but the oil contamination problem appeared, which Gore addressed with the PU coating. So eVent isn't 100% windproof. But it's very, very wind resistant: 0.1CFM comes to mind. NeoShell has a quoted 0.5CFM.

In reply to Oceanic: Gore are/have also upped their game a little with Active Shell which will be with us in the Autumn too