New – Pertex Shield – DWR-PU Coated

[Bill Fornshell]

Pertex Shield – DWR-PU Coated

This is a new line of DWR material coming from Pertex. The sample I have is called "100% NYLON, Ripstop, DWR PU Coating, Silver Printed (20D). The sample I have is the lightest version of three in the new Pertex Shield line. They come as a 2 Layer – 2.5 Layers and 3 Layers. This product is said to be as waterproof as eVent. The listed weights are 63.7 grams per sq meter, 63.9 grams and 65.3 grams per sq meter.

I weighed the 2- layer sample I have and it is 1.9 ounces per sq YARD.

My sample is Black and you can see the Silver liner layer. The material is soft to the touch and much softer than some new Gore-Tex 2 layer material I have.

I will make several rain gear items with my sample and test them. I will make them to be as light as possible which means no zippers and no pockets. I expect to use a few snaps.

Items make from the three types of Pertex Shield should be on the market by the Fall of 2008 from the typical Big Guys.

I will post my MYOG items from my sample as I finish them. With all the rain we are having here in South Texas I want to get them done before it goes away.

[Richard Nisley]

Bill – Thank you for the heads up. I also would like to get some sample material to test. The second picture appears like the inside layer isn't shiny and the third picture appears like it is.

Is the silver coating designed to be IR reflective?

Can you share your material source or do you know of another source?

What is its relative cost compared to eVENT?

[Bill Fornshell]

Richard,
The light was different. I was trying to take a picture of the silver side so you could see the pattern. I would not call it shiny more a satin like finish. The Black is also sort of a satin. Your question about the silver coating being designed to be IR reflective is a good one and I don't know the answer. I will try and find the answer tomorrow and will post it. I was told that the 2-layer works best if your body heat is close to it. I am sure you will understand the technical side of what that implies more than I do.

I don't know how much eVent sells for wholesale. This doesn't cost that much per yard but when you have to buy 550 yards at one time, plus shipping, the total cost is sort of high. I don't have 550 yards – yet.

For the unanswered questions I can send you a PM.

[Bill Fornshell]

Richard and others,

The silver color layer is not made to be IR Reflective. Here is a jpg with the spec sheet for the 2-layer Pertex Shield that I have the sample of. I expect you will understand what it all means better than I do. As for the cost, eVent costs at least twice as much as this does.

Please explain the data if you will.

Thank you.

[Woubeir (from Europe)]

Hi Bill,
what do you want to know about the data? I understand all te terms and figures but I don't know if that is what you mean.

[Oliver Budack]

Okay event is twice as expensive, it is twice the weight but its breathability is 4 times higher ;).

Günter Strunzow würde sagen: "Womit Kacke wegmachen, entscheide dich!"

Snuffy

[Richard Nisley]

Bill – Thank you for the data sheet. Based on the specs, this material is applicable for extremely light WPB rain wear as would be required for backpacking but, not bushwhacking. It is very similar to the Golite Trinity fabric. It is about half the weight and cost of the most common eVENT fabric. Its waterproofness level is adequate for backpacking applications. Its breathability will necessitate venting options such as pit zips. The DWR will wear off after about 60 miles if you bushwhack through heavy brush.

The hydrostatic head number tells us how water proof the fabric is. 10,000 mm = 1,000 cm = 14.2 PSI. 11.4 PSI is all that is required to sit in water without forcing moisture through. Kneeling in water is a tougher requirement in that a 165 lb man would exert 16.0 PSI. It has the same waterproofness as the Golite Trinity fabric, which is used for similar applications. In contrast, eVENT’s (Nylon Fabric @ 3.1 oz/yd2, 105 g/m2) hydrostatic head is 42.6 PSI but, is 1.9x heavier.

The breathability, (MVTR) using the JIS L1099 test, tells us how well internal moisture vapor will be passed through the fabric. Their spec of 7,000 puts this material in the mid range of breathability. Other options with similar breathability are as follows: Epic nylon = 6,852; Helly-Tech Extreme = 6,696; and Triple Point Ceramic = 5,306. In contrast, 3.1 oz nylon eVENT = 27,826.

The DWR value of 80/20 tells us how frequently we will need to reapply an aftermarket DWR. The durable water-repellent finish increases the surface tension on the face fabric of your garment allowing water droplets bead up and roll off. While not able to withstand much water pressure it will help keep the shell fabric from saturating and reduce the internal condensation, thus keeping you drier and warmer. The test for water repellency is called the Spray Test. Results are given by the % of the fabric still beading up after spraying water on the fabric after washing. For example: 80/20, this means; 80 points (or %) after 20 washing. The higher the points and the more washings the better the DWR is. 80/20 is about the norm for factory applied fluorine based resins. My experience with this type of DWR is that after bush whacking in heavy wet brush for about 60 miles, it needs to be replenished. By contrast, factory applied nanotechnology based DWRs will typically have a rating of 80/100 and EPIC will last the life of the fabric.

[Bill Fornshell]

– Tom,
Do you agree with Richard? Do you wish to add anything to his comments? You don't have to agree on all or any points.

– Oliver,
The cost I am talking about is the wholesale cost at the Mill not on the rack at your local outfitter.

I don't buy anything made of eVent because of there policy for who they will or will not sell their material to.

Richard,
You have impressed me with the detail of your post. But your post always impress me with your technical knowledge.

OK, Is it worth fulling with?

How about for trail hiking such as on the AT? Light weight rain gear with one or more clever and light weight venting options and maybe a pair of rain mitts.

I don't go bushwacking much and when I need to go into thick stuff on purpose I wear my old army gear.

[Richard Nisley]

Bill – You, said, "How about for trail hiking such as on the AT? Light weight rain gear with one or more clever and light weight venting options and maybe a pair of rain mitts." It is a good solution for your intended application as well as bivy and tent fabrications as an alternative to 1.8 oz Epic.

The lightest Epic fabric, that I am aware of, is 1.8 oz (61 g/m2) which is comparable to Pertex Shield’s 63.7 – 65.3 g/m2. Epic's water pressure rating is only 1.9 – 4.0 PSI versus Pertex Shield’s 14.2 PSI. Epic’s average MVTR is 6,852 which is comparable to Pertex Shield’s 7,000. Freezing moisture in the fabric lattice should not be an issue with Pertex Shield as it is with Epic.

[Bill Fornshell]

Richard,
Bivy and Tent?

Bivy:
– My MYOG
Pertex Quantum and Cuben Bivy weighs just under 3 ounces.

If I would substitute Pertex Shield for the Quantum the total weight would go to 5.74 ounces. It would seem that the new Bivy would now be water proof. Am I correct with this though? If this is correct I could get by using my small poncho / tarp even in hard to blowing rain. I would have 2 waterproof layers. The Cuben Tarp and the Pertex Shield.

Tent:
– I am not really into tents but if I made one I would use Cuben Fiber for it.

My sample piece of Pertex Shield is 3 yards long by about 55" wide. I don't think I can get another sample.

So my question falls back to what to make out of the limited amount of Pertex Shield material I have.

I want to test this material by making some item of gear that if it works would replace something or be a big improvement over something now being made out of a different material.

My definition of improvement is something lighter than it replaces or something that works so much better that a small amount of extra weigh (2 ounces or less in the case of a Bivy) is worth the change.

If I went for a Bivy I can cut the necessary material and maybe still have just enough Shield left for a sort-of rain jacket.

I am not ready to cut yet.

[Richard Nisley]

Bill – You are correct that your new bivy (Pertex Shield in place of Pertex Quantum) would now be waterproof.

I think that using your 3 yd. sample for vented rain wear would yield you the most benefit. You already have a water resistant bivy and a tarp and this is a much more flexible system than just a waterproof bivy for your AT adventure. It is a real pain getting into and out of a waterproof bivy in the rain.

[Bill Fornshell]

Richard,

I didn't mean that I would give up a tarp but that my small Cuben Poncho / Tarp along with a Pertex Shield Bivy would keep me dry / dryer even in a hard blowing rain. My small Cuben Poncho / Tarp and the Quantum Bivy worries me in a bit in a hard rain. I have been thinking about making a larger Cuben Tarp.

As for a waterproof Bivy without a tarp. I played that game years ago trying to use my OR Advanced Bivy alone. One summer night in a very hard rain I decided that I had made a mistake. It was one of life's funny moments but not to be repeated.

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