Several people have asked for details about the new ultralight 40D ripstop heat sealable fabric available in the shop. At 100 grams per square meter (3 ounces per square yard), it’s very lightweight and packs down very small (similar to a modern tent fly fabric), but it’s surprisingly strong and heat seals very well because it doesn’t melt easily like other lightweight heat sealable fabrics I’ve tried.
It’s obviously not as puncture resistant as the 210D fabric, which is nearly three times the weight, and if there’s significant tension on the 40D a rip will propagate once you get it started in spite of the ripstop grid. That’s normal though… I’ve never met a ripstop fabric that lived up to its name.
I haven’t had a chance to test the tensile strength yet myself, but I do plan to make a new fabric comparison video soon. The manufacturer’s test, done before the TPU was added, indicates a breaking strength of over 400 to 600 Newtons per 50 mm strip – that’s 90 to 130 pounds per two-inch strip, or about 40 to 60 kg per 50 mm. The TPU adds even more strength, so it’s pretty strong in spite of the light weight.
The TPU coating is thinner than TPU on the heavier fabrics, which makes it supple and packable, but it’s still airtight, and heat sealed bonds are very strong. I made a little inflatable pillow to test it and it worked very well; in fact, I think it’s easier to work with than the heavier fabrics because it’s thin and heat conducts through it very quickly, which makes heat sealing a snap.
I like this fabric a lot, and I think it will be great for inflation bags, ultralight seats, ultralight packrafts, and other projects (an ultralight dry suit, tarp, packraft sail, stuff sacks… the list goes on).
The thin threads take dyes very well, too, so the colors look great!