The binding resin must be compatible with the abrasive, e.g. comndum, but above all with the substrate. In the case of copper cylinders. microcracks are likely to occur, so that hard binder films cannot be used. Such films can even exhibit internal stresses. Products with a more easily controlled flexibility are so be prefered. e.g. polyurethanes, polyvinyl acetate copolymers, acrylate co and terpolymers and methacrylates, as well as bulk polymerised methyl methacrylat/rubber derivatives provided these are sufficiently hard.
Much harder binding resins can,however,be used for ceramic substrates, e.g. urea-formaldehyde or phenol-formaldehyde resins. Any tendency to become brittle and crack can be counteracted by incorporating a small amount of filler. These systems are recommended especially where wet grinding operations are intended.