Could you directly relate inflatable pad durability with the thickness of the material?

I just noticed that most of the Klymit pads (www.klymit.com) are 30 denier on the top, 75 denier on the bottom.

What is an Exped Synmat UL7? I seem to remember reading that the Exped Synmat UL7 was 15 denier fabric, maybe 30?

What about the various Neoair's?

I am curious because I recently had a pad failure on my Exped Synmat UL7 (a small cut from a pointy/sharp rock in the shoulder area, my weight is 255lbs). I am curious about pad durability going forward.

15D or 30D versus 75D sounds like a big difference. Is 75D fabric 5 times stronger than 15D fabric?

Thoughts?

Edited by TylerD on 04/09/2012 14:21:08 MDT.

You are overthinking this. It is clear that all of the pure air pads have leak issues across the customer base. Klymit, BA, Thermarest...... No need to compare material thickness. This is a case in which larger manufactures have done what the ultralight community has asked. Notably offering very lightweight and comfortable pads at the expense of durability.

The manufactures are giving us the lightweight opportunity and shifting the need for care based on conditions. For my neo air in the Sierras a 30d silnylon floor and 1/8" of ccf are the choice. I don't know if this is the solution, but it is working so far. If/when this fails, I'm thinking I will move to two 1/2" ccf pads. One full length and one hip to shoulder. Yes, pads are my luxury in gear weight. The trouble with a thicker ccf pad solution is dealing with the bulk.

I don't think I am over-thinking.

If an Exped Synmat UL7 is 15D or 30D fabric (possibly top/bottom?) and Klymit pads are 30D top/75D bottom I would think that makes for a pretty substantial difference in durability.

If that is the case I think it would be worth exploring the thickness of the fabrics being used on the various inflatable pads.

Ty, I think this is a good question. Abrasive damage, pinhole punctures (by thorns), and tears are different kinds of failures, and the degree to which a fabric is susceptible to each kind of failure depends on a combination of fiber properties (material, orientation, etc.), denier, weave, and coating.

But you don't need to know all of those characteristics of every available pad in order to make a reasonable comparison. If you want to use an inflatable pad and you want better durability than your Synmat UL7, I would suggest considering some of the variants that have a higher denier surface fabric. I think your reasoning seems correct. The heavier fabric should be much less likely to tear. And if you know you will be camping in an area that abounds in sharp rocks and thorns, bring a thin foam mat to put underneath.

I don't want to know the thickness of every pad, just of the common ones. Really now that I know the Kylima thickness (30D/75D) and I think Synmat UL7's are 15D, possibly 30D I would like to know what some of the common NeoAir pads are for comparison.

Really my thought so far is the Kylima pads are apparently substantially thicker and I would assume more durable. What I am thinking about is pairing a Klymit Inertia X Frame at 9.1 ounces with various ccf pads depending on weather. The reason I am interested in the Klymit pads is the 30D/75D but still very low weight (obviously because of the cutouts). Or heck if these Kylima pads are 5 times more durable than an Exped maybe I just need to switch to one of these and call it a day.

I am surprised all the engineering minded people have not jumped in here to discuss fabric thickness as relating to durability. 15D vs 75D just seems like such a big difference.

I read all these threads talking about R values vs weight but never about durability other than anecdotal evidence like 'I have XYZ pad and it has never let me down'.

Edited by TylerD on 04/09/2012 14:51:06 MDT.

I believe the NeoAir Xtherm that is coming out is a combination of 30D and 70D materials, bottom and top respectively. Of course there's no durability data to correlate yet.

The original NeoAir was listed with 30D fabric.

Not all failures are fabric thickness related either. Delamination and leaky valves or seams around valves are also a source of failure to consider.

Ty,

You asked, "Is 75D fabric 5 times stronger than 15D fabric?"

No, it is only about 2.24x as strong; 15 denier nylon (1.2 g/cm3) yarn is .0227 cm in diameter and the 75 denier nylon yarn is .0508 cm in diameter.

There is even less of a difference in the weight ratio because fabrics made from finer yarns are naturally more finely-woven, otherwise the fine yarns would be widely spaced and the fabric loose and unstable. Also the coating weight is approximately the same. The weight difference between the two fabrics could be as small as 30%.

Edited by richard295 on 04/09/2012 23:17:20 MDT.

But the 75D thread has 5 times as much cross sectional area than the 15D. So it terms of tensional strength, yes, it would be 5 times as strong.

But for punctures (not tears) I think that this is irrelevant. The thorn just has to get between the threads, no necessarily cut them.

Steve

Edited by geokite on 04/10/2012 11:05:10 MDT.