Remarkable damping material


diyAudio Moderator Emeritus
2002-10-24 10:19 pm
I've spent the last several days in Duesseldorf at a large plastics trade exhibition. Although this is a working trip, I always have an eye open for things related to my favorite hobby. While visiting with Kurary, a large Japanese manufacturer of styrene elastomers, I was shown a material called Hybrar. It's a styrene triblock copolymer which is elastomeric (rubbery). In the hyrdogenated grades, the energy absorption is remarkable- although if you squeeze a piece of it, it rebounds just like rubber, rapid impacts are totally absorbed. In one demonstration, a ball of Hybrar was dropped on the table alongside of a similar size/weight ball of a conventional synthetic rubber (in this case, Septon). As expected, the Septon bounced very well. The Hybrar bounced not at all, yet showed no inelastic deformation. I've never seen an unfilled rubber material that acted like this!

The engineers at Kurary promised to send me a few pounds to experiment with. I'm thinking that this could be a perfect material for turntable use... not to mention ultra-lossy speaker surrounds and possible a constrained layer in speaker panels.

As usual, no financial interest here.
Looks like an interesting find! I "Googled" the name and found some additional information. It appears to be either manufactured or distributed by "Kuraray Co. Ltd", and their website lists "Audio" as an application for the product. Perhaps someone else has also discovered the product.

In my search, I could find neither US distributors listed, nor any pricing information, except the announcement of a price increase effective 5/1/2010. The price listed is EUR 0.20 per Kg, but no explanation is given whether this is the price, or just the amount of increase. I'd guess the latter.

I can think of any number of applications for the product, but since it's an industrial product, the trick may be to obtain it in something less than "container" quantities.
Interesting. What's your impression on how it might stack up compared with the EAR materials? They have one very cool swag piece which is a golf ball molded from their isodamp material. When dropped onto concrete from 4 feet it will bounce maybe 1/8" to 1/4". I don't golf but I hear that when driven by one it goes about 3 feet :D.