Cuben Fibre strengths

Joe @ Zpacks did a video a while ago comparing tear strenght. Not a scientific test but good start. Here is the link

Not sure of your intended application. I have made a tipi out of 0.74oz/sqyd and a flat tarp out of 0.51oz/sqyd. I did reinforce the tie out points and find the tarp plenty strong.

Cheers.

Hi Mario,

Great link, thanks.
I had seen it before and it certainly is useful and worth watching again, ideally i am after something of a more technical nature.

A good friend has told me that the CF material is the same on 1oz (compared to .74oz) but that 1oz has a extra layer of laminate.

Is this the case for the difference between .51oz and .74oz?

I'm also interested in hearing peoples thoughts on the real world differences between the 3 weights.
The extra laminate must give some strength otherwise why would people use the heavier weights, but what sort of strength does it provide, is it stronger against friction wear or tearing forces?

I don't know that much about the physics involved here , but I used to build experimental aircraft. Weight to strength ratio there was pretty critical. And I spent some time with some pretty good materials guys who made me do a simple experiment when I contemplated a very stupid (Probably would have killed me and my passengers) method of reducing the weight of a wing.

Float a sheet of newspaper in water and then try to slap your hand thru it. Word of warning: don't wallop it too hard you will break your hand. You can't do so easy not because water is hard nor is wet newspaper strong.

The strength comes from surface tension of the "bonding" of the newspaper on the water.

I'm not sure that by simply removing a layer of laminate from the cuban that you are not giving up a significant amount of strength.

Then again I could be out to lunch as I know less about double laminates and their tensile strengths than I do about foam cores and Kevlar.

Answers a lot of the questions you posed:

http://www.zpacks.com/materials.shtml

This may not be accurate but I think it's like this;
The difference between .51 and .74 is spectra content, the difference between .74 and 1.0 is thickness of Mylar layers, difference between .51 and 1.0 is both spectra content and Mylar thickness. The Mylar on both .51 and .74 is .08 (inches?) and the 1.0 stuff has a thickness of .18. Cuben is a spectra fiber grid laminated between two layers of Mylar.

Not sure on the construction differences between .5, .7 and 1.0.

All I can say is that my 11' x 7.5' cuben hammock tarp made with 0.5 has weathered some horendous weather without any problems. Last fall it withstood 80+ MPH wind gusts all night long.

I can understand using something heavier for things like tent floors or backpack fabric. But due to its rather poor repetitive wear resistance, I think there are better materials for those applications.

Thanks guys,

John,
The paper on water example makes a lot of sense John, but in this instance it's the tear resistance i'm worried about, specifically how much more tear force will 1oz take compared to .74oz

Drew,
The Zpacks page is good, but i'm asking if anyone has experiences of how well .74oz stands up compared to 1oz

Sam,
Great post, thanks
Any idea how much more tear resistant the laminate is?

Mike,
I am looking for something stronger than .74oz, so .5oz will not be much of a recommendation for my type of camping unfortunately

Hey Mark,
When it comes to tear resistance, I believe that comes from the spectra content. The laminate has more to do with abrasion resistance. The thicker laminate will definitely help some with tear resistance though.

So .74 will be more tear resistant than .51, but have basically the same amount of abrasion resistance. 1.0 will be slightly more tear resistant than .74, and a lot more abrasion resistant.

0.74 is, I believe, the best weight for tarps and canopies, while 1.0 or heavier is better suited to ground sheets. 0.51 has been used by ZPacks on most all their shelter canopies and tarps, and from reports has been holding up fine. So it definitely works, But 0.74 just gives a bit more comfort in knowing it can withstand a bit more "abuse" with very very little weight penalty.

But if you want a bomb proof shelter, 1.0 can be used for the canopy or tarp and still be lighter than silnylon while giving you all the added benefits of Cuben.

So it's just a compromise of what you want/need for your intended purpose.

(I'm no expert on this stuff. But I believe most of this information is correct, if not just my opinion.)

Makes sense Sam, thank you

Yes 1.0 is also prettymuch 1.0 oz / yd. Unlike "1.1" silnylong that is like 1.5 oz or something finsished weight.

1.0 would be bomber, my freind Cesar V. Got a 1.0 tarp from Zpacks and its very sexy. Nice black color which is the best color hands down! It is about 1.7 – 1.9 times more heavy than .51 taprs though. Less than double the weight, but will never need replacing, and tie out wont be ripped out or stressed.

Do you or your friend have any pics of his tarp please Michael?

Cheers
Mark

Here are some charts from Cubic Tech relaying the characteristics, including tear strength, of a few of the different fabrics that they offer:

0.51
0.75
0.8
1.0

Do I read those sheets the right way?
Failure strength is better with .51 (68 lbf/in) than with .75 (67 lbf/in)?

The .75 oz isn't what is normally referred to as .74 oz cuben – that is the .8 oz here.
The .75 oz is the same dyneema as the .51, but with a double thick mylar layer.

Fantastic find and post schassey, exactly what i was looking for, thank you