Tech Talk
What are “Rubber-Bonded Grinding Wheels”?
Rubber-bonded wheels are made by selecting the grain, sieving it like before, and then kneading the grain into a natural or synthetic rubber. Sulfur is added to the mix as a vulcanizing agent and then the mix is rolled between steel rollers to form a sheet of the desired thickness. The grinding wheels are then cut out of the rolled and sized sheet rather like cookies, using a cookie cutter. The wheels are then vulcanized under pressure at temperature of 175˚C (350˚ F).
Rubber wheels claim a little less than 10 percent of the market. They can be made extremely thin, as thin as 0.050 mm (0.0002 in). These very thin wheels are used for slitting fountain pen nibs. Conversely, very thick wheels can be produced for centerless grinding control wheels. Other applications for rubber-bonded grinding wheels are in the bearing industry, where extremely high surface finishes are required.
