Vibratory finishing of polyurethane pieces

I have been casting products out of a clear polyurethane for a number of years. I am developing a couple of new products (small -- approximately a 2 ounce cast)that have some minor sanding/finishing needed. To sand and buff these parts out by hand is too labor intensive and I am searching for some vibratory media options to clean these parts up. The material is similar to the clear coat of an automotive finish and is a shore D-80 hardness. The urethane is extremely durable but accepts sanding. I could opt for sand finishing to a dull finish and then topcoating them with a clear but that again becomes labor intensive. Does anyone have any suggestions for a finishing media that would not simply "bounce off" and a subsequent polishing media? Thanks in advance for any suggestions. Joe H

Dear Sir,

We are using centrifugal disc finishing machine for this type materials. This machine can process 50 shore A hardness rubber or PU with ceramic abrasive chips.

Hmmmmmmm! You know, that is the material that is used to line big mass finishing equipment work chambers. These liners are rigid and do wear but that takes a lot of time. Then again, if you use a high energy centrifugal system with a big, coarse ceramic media, you might achieve the results you are looking for in a reasonable time frame. You have to also remember that this will produce a uniform finish, but outside edges may be effected to a greater extent. If you are interested, send me some samples for processing.