At the US Nationals last month, Gregg Snouffer and I were chatting about boom materials. He talked about "Cyply" and said that he had never used it.
Subsequently, we obtained a data sheet from the manufacturer, Red Seal Electric Co., a US based company. http://www.redseal.com/
David Hirsch, Tibor Horvath, Andrew Cross and I have been going over the data sheet and have been discussing this material.
Cyply is a trade name for a kind of GFEC that features multiple layers of unidirectional glass fibers laid down between layers of resin. The product line has three versions of filament patterning: unidirectional, cross ply (0 and 90 deg) and isotropic (0, 45, 90 deg). It was the isotropic that caught my attention. I wondered if a third direction of glass fiber might add more strength and toughness to the material.
Another function that the multiple layers of unidrectional glass fibres, as described somewhere in the literature, is a reduction in the self abrasion present in glass fibre cloth. I think Red Seal's theory is that because the unidirectional layers of fibre are isolated from each other by a layer of resin, continuous flexing of the material does not cause the cross-wise fibers to wear through their neighbor due to abrasion. This is supposed to allow the material to maintain its stiffness over repeated flexure. Tha sounds like a very good thing for boomerangs, especially mine, which crash often!
Having become interested over all the conjecture, Andy and Tib compared the Cyply specs with some of the GFEC (G10) we have been using. I'm not a materials guy so I will paraphrase Tib and Andy's quick assesment - Tib thought that the two directional cross ply specs looked a little better than the 3 way cross ply (isotropic) and Andy thought maybe the Cyply product looked a little better than the G10, although he still prefers G11 to G10.
David, Tib, Andy and I all have a copy of the data sheet (pdf). Let one of us know if you'd like a copy.
We still don't have all the information yet on availability from the supplier but an inital quote shows this material more expensive than standard G10 but still less expensive than carbon fiber. David is going to try to get some sample material and I'm entertaining the idea of obtainig a sheet big enough to make 3 or 4 Voyager style booms.
I'm wondering if anyone else on this has had experience with this type of material, and if anyone might be interested in splitting the cost of some material to try it.