Posted by Wayne on October 04, 2000 at 16:41:07:
In Reply to: OKAY, here we go!!!!! ;-) posted by MHK on October 04, 2000 at 15:58:16:
The piece of data that I could not locate is the thing that was called "figure of merit". It is a compensation for the fact the material cannot change its volume exactly the same as the gas bubble's that are in it. In normal wet suit material, the design is such that a large amount of gas is present to improve its insulating properties. The study you quoted showed that the reduction is about half of what you would expect based the behavior of the gas. This seems to indicate that the density of the material has been reduced by about half through the introduction of the gas. Assuming this to be the case, then neoprenes that are NOT designed to provide increased thermal insulation would be substantially less affected by the same pressure changes.
What I would be very interested in is a table of compressibility of popular materials -- especially those used in WETSUITS since less gas, would mean less initial insulation, but less reduction in insulation properties at depth. I am sure this data is available from the neoprene manufacturers. I hope and expect that the wetsuit manufacturers have considered this in their selection of optimal materials.
I have used neoprene (the solid sheet bubble-free type) in several tool and fixture designs where I took advantage of its flow and resilience characteristics (squeeze here and it pokes out there and applies about the same pressure in all directions). I accidentally got some that was foamed and it did not work worth a dang in the same tool! The stuff in our wetsuits is WAY more foamed than that stuff (explaining why we get cold at 100 feet in a wetsuit that is warm in 30 feet).
SO while I am not getting involved in the bet, I think it brought up some interesting discussion topics that may lead us to being better consumers -- or just more boring at parties!
Wayne