JohnRich 4 #1 June 9, 2006 From an article in "Backpacker" magazine, March, 2006: Welded Bliss By Marcus Woolf The development of stitchless technology is promising to make packs, jackets, and other outdoor gear up to 50 percent lighter. If Paul Kramer gets his way, Mountain Hardwear will soon say goodbye to needle and thread. "Ten years ago, the average weight of a waterproof jacket was 800 grams," says the vice president in charge of design. "With the welding methods we're working on now, we'll be under 350 grams no time." Kramer is referring to a construction technique that binds fabrics without using stitched seams. The process is similar to one that's been used for years in making dry bags: A high-tech adhesive is spread between fabric layers, then heated and bonded using radio frequencies or ultrasonic waves. Until recently, though, there were no glues that worked with the porous fabrics used in packs, boots, and apparel. Much of the credit for finding new glues and bringing stitchless technology to outerwear goes to Arc'teryx, which began experimenting with welded seams in the 1990s. The company turned to Bemis Associates, an adhesive giant with roots in the woodworking industry. Using a glue originally formulated for countertops, Arc'teryx launched a line of waterproof/ breathable jackets with welded chest pockets in 1998. Since then, other companies have worked with Bemis to refine the formulas. Bemis now makes adhesives for hundreds of fabrics used in everything from boots to packs to soft-shell jackets. Weight reduction is one benefit, but Marmot spokesman John Cooley says the improvements most likely to notice are in fit. "We can do Ion arcs and angles that are impossible with sewn seams," he says. And they can craft clothing that's more streamlined. A good example is welded belt loops which reduce bulk beneath your hipbelt. Welded seams can also be stronger, says Gaston McMillan of Mountain Hardwear's R&D department, citing lab tests that showed, a 5 to 10 percent increase in tear strength. Besides apparel, welding is making its way to tents, boots, and packs. Timberland'is introducing boots with welded uppers, and Arc'teryx's new AC2 packs are almost entirely welded, resulting in a waterproof pack that's up to 40 percent lighter than a comparable model. The main drawback to welding is price - $260 for Mountain Hardwear's 13-ounce Swift Jacket and up to $425 for Arc'teryx's packs. "Welding requires new machinery," says Kramer. "And the factories don't have much competition, so they charge more." But the technology has a firm grip on the outdoors market. "Gloves," muses Bemis spokesman Chris Parlee, "that's the next thing." * * *"Parachutes," muses skydiver John Rich, "that's the next thing." Quote Share this post Link to post Share on other sites
jumper03 0 #2 June 9, 2006 hmmm.... now I need to go look at my arcteryx pack... I bought it in 2000 so it probably has welded seams and I never noticed!!! On the flip side though, just a 500 gram weight savings doesn't mean much when you're going to be hiking out close to 50 kg of rock.....Scars remind us that the past is real Quote Share this post Link to post Share on other sites
SkymonkeyONE 3 #3 June 9, 2006 At least two companies displayed prototype canopies with this technology at the last PIA symposium. One, Atair, had a Cobalt 95 that had several hundred jumps on it already without any signs of odd wear or failure. Dan, if you are reading this correct me if I am wrong with the numbers Chuck Quote Share this post Link to post Share on other sites
JohnRich 4 #4 June 9, 2006 QuoteAt least two companies displayed prototype canopies with this technology at the last PIA symposium. One, Atair, had a Cobalt 95 that had several hundred jumps on it already without any signs of odd wear or failure. Wow! In addition to lighter weight and smaller pack volume, I also like this part: "...the improvements most likely to notice are in fit. 'We can do Ion arcs and angles that are impossible with sewn seams...'" Does this mean that there are design and shape limitations based upon what a sewing machine can accomplish? And if those restrictions are eliminated, then this may open the door for new design possibilities for parachutes. Fantastic stuff. But I'll let someone else jump the leading edge parachutes first... Quote Share this post Link to post Share on other sites
tr027 0 #5 June 9, 2006 Chuck, don't we really need welded wingsuits?? "The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957 Quote Share this post Link to post Share on other sites
Kris 0 #6 June 9, 2006 The only downside I can think of is what happens when you need to replace a cell, stabilizer, etc...? You can't just simply unglue the thing with a solvent can you?Sky, Muff Bro, Rodriguez Bro, and Bastion of Purity and Innocence!™ Quote Share this post Link to post Share on other sites
Brains 2 #7 June 9, 2006 QuoteWow! In addition to lighter weight and smaller pack volume, I saw the cobalt 95 in person, and the lineset weighed more than the canopy. Never look down on someone, unless they are going down on you. Quote Share this post Link to post Share on other sites
TCMRigging 0 #8 June 9, 2006 A welded canopy would be a bitch to pack, no stitch holes for air to escape through would suck. We may have to pay packers more than 5 bucks for those. It's a good thing I don't pack anymore :) Chris Quote Share this post Link to post Share on other sites
JerryBaumchen 1,050 #9 June 9, 2006 Hi chuck, I believe that the Cobalt in JAX was not welded in the seams. The fabric was a 'weldment' process where the threads were oriented such to eliminate the 'V' tapes on the ribs. These threads were then bonded between two layers of fabric. The seams were sewn; or my eyes are going bad. Jerry Quote Share this post Link to post Share on other sites
mark 102 #10 June 9, 2006 Hello Jerry! Until Dan chimes in, I think we're the blind men describing the elephant. I remember sewn seams on Dan's canopy, but although I remember him saying the fibers in the fabric could be oriented to substitute for the reinforcement tapes common in ripstop ribs, the fiber orientation in his canopy was conventional right angles. IIRC, the maximum length of a piece of such fabric was just 10 meters and was hideously expensive; production of custom batches with fibers oriented exactly (and requiring ribs to be cut exactly as well) for a particular canopy would put price even higher. Dan did talk about gluing the fabric together as an alternative to conventional sewing -- but he also said that because the fabric is already relatively impermeable, absence of needle holes would make the parachute almost impossible to pack. Mark Quote Share this post Link to post Share on other sites
JerryBaumchen 1,050 #11 June 10, 2006 Hi Mark, As I remember it, the top & bottom material had the fibers at the normal 90 degrees. The rib(s) had the fibers aligned somewhat in the direction of the stresses. Also, where the line attachment tapes were at, he had a 2nd layer of fabric that was 'about' 2 x 3 inches or so. Jerry PS) Dan, where are you when we need you? Quote Share this post Link to post Share on other sites
AggieDave 6 #12 June 10, 2006 Is the canopy yall are describing the same as the Atair "plastic cobalt?" If so I don't remember seeing any fibers or thread sewing what so ever.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
cobaltdan 0 #13 June 13, 2006 im a bit rushed today but here are two links to get you started: http://www.atairaerospace.com/press/2005/04/smithsonian-spotlights-atair.html http://atairaerospace.com/parachutes/composite/ when I get the chance I will post a full update. sincerely, dan preston atair<><>Daniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
mark 102 #14 June 13, 2006 Clickies: http://www.atairaerospace.com/press/2005/04/smithsonian-spotlights-atair.html http://atairaerospace.com/parachutes/composite/ Just teasers, though. Most of the questions posed earlier in this thread are not addressed. Mark Quote Share this post Link to post Share on other sites
bch7773 0 #15 June 14, 2006 it appears the main benefits would be a lighter canopy, with possibly an increase in seam strength. the downsides are expense and increased packing volume, as there are no holes to let air out. am I reading this right? cause it sounds like the current stitching method is better MB 3528, RB 1182 Quote Share this post Link to post Share on other sites
BlindBrick 0 #16 June 14, 2006 Wonder what you'd get if you mated this technology to HMA lines and PD's new fabric? -Blind"If you end up in an alligator's jaws, naked, you probably did something to deserve it." Quote Share this post Link to post Share on other sites
cobaltdan 0 #17 June 16, 2006 "just teasers" sorry guys, didn’t mean to tease. i have a great powerpoint presentation with more detail as well as video of our fabric manufacturing machine in operation. i will have our web guy put it up on our site and post a link. some quick answers: the canopy shown at pia: actually I brought 2, one was a cobalt 95 and the other was a pulled down apex reserve. and also displayed a cobalt 350 rib with a custom fiber pattern (non uniform, starburst patterns off line attachment points) both were sewn however one had a strip of fabric adhesively bonded over the seam, making a structural bonded fabric-fabric lap joint in shear (the underlying sewn seam then becomes non load bearing). the reason for sewing it first was simply as it is an easy construction technique. with developed fixtures/machinery one could skip the sewing step all together. bonded seam cobalts: you can not pack them (extremely difficult) without some vent holes. On sewn construction ones the sewing hole perforations are enough to allow you to pack. our composite canopies are actually easier to pack than zpo as they do not swell after cocooning. very strange to see but they just sit there looking like a crumpled shopping bag. when vacuum packed they feel like a block of wood. you can knock on them. the fabric is produced on a custom machine we developed. it looks similar to a cnc fabric plotter except with 4 gantries. each one zig zagging fibers onto a moving conveyor in a computer controlled pattern i.e. + - 45' , 0', 90' for a uniform fabric with 4 layers each at 45' to each other, or e.g in the case of a large canopy each panel of fabric is made with fibers in the exact orientation to match the stress on a rib in flight. the 95 cobalt at pia was constructed with 0-90 fabric top and bottom skin and +-45,0,90 fabric on the ribs. we are now constructing the largest elliptical parafoil ever constructed for DARPA using our composite fabric, this wing is 37 cells, fully elliptical and almost 150' in span. ribs are produced with a custom pattern... sincerely, -Daniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
cobaltdan 0 #18 June 16, 2006 QuoteWonder what you'd get if you mated this technology to HMA lines and PD's new fabric? -Blind you can not adhesively bond or weld nylon zpo fabric by any method. -Daniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
justinb138 0 #19 June 16, 2006 How do the flight characteristics of the welded-seam cobalt compare to the standard one? Quote Share this post Link to post Share on other sites
cobaltdan 0 #20 June 16, 2006 QuoteHow do the flight characteristics of the welded-seam cobalt compare to the standard one? we dropped two of our autonomous guided parafoil systems, think of them as parachute smart bombs. the systems were identical in every way with the exception 1 had a zpo cobalt 40 and the other had a composite cobalt 40....they were dropped 2 seconds apart several miles from a common landing target. they flew identical headings. the composite canopy datalogged a glide ratio 65% higher than the zpo canopy. the wing we designed and are building for darpa was first constructed and tested using zpo. it proved out to have a 8.2:1 L/D . On the newest version being constructed in composite we fully expect to break a 10:1 L/D. .Daniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
JohnRich 4 #21 June 16, 2006 QuoteOn the newest version being constructed in composite we fully expect to break a 10:1 L/D. Wow! Thanks for adding all this incredible information to the thread. It's very interesting and intriguing stuff. Quote Share this post Link to post Share on other sites
airtwardo 6 #22 June 16, 2006 the composite canopy data logged a glide ratio 65% higher than the zpo canopy *** Dumb question...Why is that? Isn't a Zpo canopy 'supposed' to in theory anyway, have better flight characteristics? ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
justinb138 0 #23 June 16, 2006 Quotethe composite canopy data logged a glide ratio 65% higher than the zpo canopy *** Dumb question...Why is that? Isn't a Zpo canopy 'supposed' to in theory anyway, have better flight characteristics? I believe the composite he's referring to isn't a nylon fabric. Quote Share this post Link to post Share on other sites
