phourgenres
08-17-2015, 21:17
Is anyone familiar with the differences between xpac and dyneema x fabric? The best I could find researching is xpac is 70d, dyneema is 200d? If that's the case, why do they not list a weight difference?
Just Bill
08-18-2015, 09:04
Dyneema X is basically a fabric with a double ripstop grid- one grid at 90* one at 45*.
After that, it also has a PU coating on the backside.
http://ripstopbytheroll.com/products/210d-dyneema-x-gridstop-slate-blue
http://thru-hiker.com/materials/coated.php
Xpac is a bit more like a piece of plywood, there are many layers laminated together, including the 22* grid of heavy reinforcement.
It comes in over a dozen versions, so that is mainly where your confusion is coming from. I believe you can get it as low as 3 oz a yard and roughly 30d yarn.
The 210d version is VX21. Quest carries a few different varieties- http://www.questoutfitters.com/coated.html#X-PAC
D (denier) has to do with the thread size used to weave the base cloth, but that doesn't apply as well to something like X pac because of all the layers used.
Dyneema X is fairly soft, very tough, and waterproof for many years. It is just a "cloth" though with a heavy PU coating on the backside.
Xpac is a sandwich of the grid, fabric, and a PET layer.
I have a small roll of Xpac if you wanted to try some out.
I found it very stiff, and probably a product better suited to making a drybag than a pack personally. That said, many people do like it. It can get hard to sew anything complicated, but assuming you're buying something from somebody... that's their problem. Much like Cuben, it was developed as sailcloth for boat racing, but they do have a few flavors that are hard to find that are better suited for gear.
Personally, I think one of the best fabrics for your buck is HyperD 300- http://ripstopbytheroll.com/products/hyperd-300-black
This is much softer, easier to sew, half the price, and an ounce per yard less than Dyneema. I think Kyle (owner of RBTR) is making some of the best blends of function and economy fabric around. This is the material I use now. It is a 300d fabric with PU coating.
I'd consider it a very good alternative to the Zpacks hybrid material, especially as that costs an astounding $40 a yard vs $9.30. Saving roughly 1 ounce in a pack to me isn't worth quadrupling the cost. If weight was a concern, I'd use 1.6 oz per yard Hyper D http://ripstopbytheroll.com/collections/1-6-oz-hyperd-ripstop-nylon
PU coatings do eventually harden and de-laminate, but to be perfectly honest, very few people will use a pack long enough to experience that issue and the coating is better than the old days. There have been occasional reports of Xpac delaminating.
Keep in mind... unless you seam seal your pack and design carefully, waterproof fabric is not waterproof. They still sell pack covers and WP liners for a reason :D