Pack Material - durability difference between polyester and nylon?

[MyFeetHurt]

Morning all.

So say there are 2 packs, roughly the same weight and capacity, one is made using '210 denier nylon' and the other '420HD polyester ripstop'. Which of these is the tougher material? Thanks.

[Leo L.]

From the physical properties, Polyester is about 20% heavier and does not absorb water. Best UV durability.
Nylon (Polyamide) is more light weight but does absorb water and does somewhat lengthen by doing this. Not perfect UV durability.
The tensile strength of both materials is about the same.

But what the fabric makes out of these properties might be something different.
A 420 thread is double the weight (per length) than a 210 thread, but this still does not tell too much.
Ripstop is a good trick to make the fabric durable but still ightweight. HD means, very tightly woven.
Again, all this does not tell much, there are many ways to finish a fabric, like Silicone or Polyurethane coating.

If I would venture a wild guess, I'd think the 420HD ripstop Polyester is tougher.

[Casey & Gina]

It really depends. 210D nylon can be tough stuff (Dyneema Gridstop X comes to mind), but I'd bet that the 420D polyester is, side-by-side, tougher. In order for the packs to weigh the same, the polyester one must have less fabric. That means less functionality or features. More than "which is tougher", which do you prefer? I personally really like the properties of nylon over polyester - the feel and way it handles. My pack is 420D nylon packcloth, and I love it. The only polyester pack I ever had was rubbish (not because of the fabric, mind, but just generally poor construction and design). It was probably 1000D but not an HD weave - it was definitely not ripstop either. It did end up with several holes before I ditched it, which I find nylon more resistant to. I think that is because nylon is more abrasion resistant - something is more likely to slip against it while polyester will "catch" it and be subjected to more damage as a result. In real world usage, that abrasion resistance property will likely increase the life of the pack, but it depends on the type of abuse it is subjected to. My nylon pack has 100D cordura on the bottom portion for this reason - being set down on rough ground is not a case where abrasion resistance is of benefit, but sheer puncture/cut resistance is. Most packs are nylon, and all the high-end ones are, so I think that says something. Then again, there are various grades and qualities of both, even when the denier is the same.

[Feral Bill]

Pick the one that fits you best.

[MyFeetHurt]

Thanks all. Ended up picking the polyester one, we'll see how it does. Appreciate the replies.

[Malto]

There was a thread somewhere on backpacking light documenting real life testing of durability. At the risk of creating a rant you could probably Google it but it probably doesn't matter since you have made your purchase.

[Traveler]

There was a thread somewhere on backpacking light documenting real life testing of durability. At the risk of creating a rant you could probably Google it but it probably doesn't matter since you have made your purchase.

Great.... Your comment shattered my self confidence to the point my self esteem has been compromised and completely ruined my life.

Thanks a bunch.