As abrasive grit types for abrasive belts, corundum and silicon carbide are used almost exclusively. For large material removal volumes, as is common in steel machining, zircon corundum, for instance, has proved useful [DENN89, N. N.6].
However, for the fine machining of bearings, crankshafts, camshafts, sealing surfaces, fibre-reinforced plastics, audio and video magnet heads and storage discs, abrasive belts with diamond or cBN are also made use of [N. N.3].
In addition to individual components, the coating technology is decisive in the effectiveness of abrasive belts. Considering methods of grit capture, we differentiate between mechanical and electrostatic scattering. Both methods have a different grit position relative to the backing material, resulting in alternative process behaviour as well.
In mechanical or gravity scattering, the grit to be captured falls on the backing material, which has been coated with the basic bond, by means of a distribution device. In this way, the lion’s share of the grit becomes fixed in the binding agent
layer. The loose, non-adhering abrasives fall into a collecting funnel with a change in the path of the backing material. The carriers coated in this method permit only a small amount of chip removal volume due to the small amount of chip space.
Such disadvantages of classic gravity scattering can be avoided with electrostatic scattering. In this method, the backing material coated with basic binder is directed with the binding side pointing down at a precise distance over a transport belt covered with abrasive grit. The grit is oriented by the transport belt by an electric field and embedded into the basic binding layer of the abrasive grit carrier. With this technique, a much larger chip space is permissible than in gravity scattering. In addition, electrostatic scattering guarantees an even grit distribution and a reproducible scatter image.