View Full Version : Waterproof fabrics: A primer

2005-04-03, 21:06
When Mallory's body was discovered on Everest, he was wearing woolen underswear, and a tweed jacket. Things are come a long way since then in terms of climbing gear. I'm here to do a bit of a comparison between different fabrics available to outdoorsman today.

1) Gore-Tex: In the last twenty years, gore-tex has re-vamped the waterproof garment industry and still holds most of the market. Gore-Tex itself is not a fabric, in reality it is a membrane of PTFE (think Teflon) that is heat laminated to an outer layer of either nylon or polyester. The idea of gore-tex is that the PTFE has millions of micro-scopic pores that are large enough to allow body perspiration to escape, but keep rain drops out, as they are too large to enter the garments pores. Unfortunately, gore-tex has a few drawbacks: Gore-Tex is completely dependant on the outer layer of the garment, PTFE is extremely fragile and that is why the makers of gore-tex put in (usually) a nylon liner to protect the film. In order for the garment to work, the outer layer of the garment must be treated with a DWR (Durable Water Repellancy) this treatment causes water to bead on the surface of the garment. Unfortunately, this treatment is temporary at best. In hours of heavy rain, the DWR will wear off, and the outer fabric will become soaked. When this happens, gore-tex stops breathing, and the fabric functions much like a PVC raincoat, you sweat like a pig, but there is no-where for the perspiration to escape. It's the same in cold weather. When the temperature drops to just a few degrees below freezing, the PTFE film seals the pores, and the garment will not breathe. However, most people are sucked in by marketing and are more than willing to spend $300 dollars on a gore-tex jacket, that will last no more than a few years before the fabric de-laminates. However, the good thing about Gore-Tex is that is completely waterproof and seam sealed. As long as you're not sweating too much, gore-tex will keep you dry. Guaranteed.

2) Pertex/Super Microft: As I explained earlier, gore-tex is not quite as breathable as they make it out to be. A new fabric coming out of England is called Pertex. It is a simple solution to gore-tex, it's a high-sensitivity nylon that is completely windproof and highly water repellent. The principle of pertex is that it is completely windproof, and has enough of a water repellency that if the wearer has on a fleece/fibre-pile liner, even if the rain is too much for Pertex, the heat from the wearers body will quickly drive the moisture into the atmosphere. The only drawback is that is not quite as waterproof as gore-tex. But, everyone has their preferance.

3) Cotton: The mantra of most outdoorsmen (and women) is the holy quote "Cotton Kills." This is true if cotton is used as a thermal or base layer. Once wet, cotton becomes extremely cold and refuses to dry out. This can very easily bring on hypothermia, which can lead to death if not treated fast enough. BUT: There are 3 types of cotton available to the public, all of which go against the grain of any modern climber. These are:
-Ventile cotton. Originally developed in 1941 by British Scientists, Ventile clothing is made the top 2% of the worlds cotton crop. The fabric is woven using 30% more fabric than conventional woven fabrics. The principle of Ventile is that is completely uncoated, no laminates or DWR's to fail. Once wet, the cotton fibres swell up, and coupled with the tight weave produce a very weaterproof garment, and unmatched breathability. This fabric is so good, that is used in military's all over the world as immersion suits for pilots flying over cold water.
-Epic, by Nextec. The principle of Epic cotton is a new one, who knows if it will catch on. Ordinary cotton is treated with a fibre-encapsulation process which (supposedly) renders cotton highly water repellent, warm, and improved drying times. It's a lot cheaper than Ventile too!
-Quarpel treated garments: Similar to Epic, Quarpel is a water repellent treatment that the military has been using since WWII. It's pretty much the same as Epic cotton. Both Epic and Quarpel treated garments are actually quite waterproof, and dry quite quickley. The only drawback with Quarpel and Epic is that if the garment is washed with Bleach, the treatment will disappear and you're left with regular cotton. M65 jackets are a prime example of Quarpel.

I hope this helps!



2005-04-04, 00:14
I believe you missed one thing you should have mentioned. Epic is not only cotton.

In fact, from what I've seen, most jackets / rain wear made of Epic are actually encapsulated polyester or nylon.

What types of fabric can the NextecŪ process encapsulate?
Polyester, nylon, cotton and stretch woven fabrics. Our encapsulation process can be used to produce more types of performance fabric than any other treatment.
site (http://www.nextec.com/qa/clinic.php?clinicPlace=8)