Many people never come into contact with a grinding machine in their life. These tools are used to wear down surfaces for industrial purposes, commonly called lapping. Whether sculpting a tool, designing a car or constructing a building, grinding machines are likely to be involved. Here are 7 facts to know about these interesting devices.
- Lapping is a machining process, in which two surfaces are rubbed together with an abrasive between them, by hand movement or using a machine.
- Lapping with diamond provided a more effective lapping solution than conventional abrasives for an alumina wafer. In one particular instance, diamond eliminated the hand-polishing step, reduced the cycle time by 30 min, saved $14.87 per hour in overall costs, and reduced cleaning time and resources.
- Taken to the ultimate limit, with the aid of accurate interferometry and specialized polishing machines or skilled hand polishing, lensmakers can produce flat surfaces to 30 nanometers.
- Surface roughness is defined by the minute variations in height of the surface of a given material or workpiece. Roughness is usually expressed in microinches. A surface that exhibits an surface roughness of 8 consists of peaks and valleys that average no more than 8 microinches over a given distance.
- Surface accuracy or flatness is usually measured in Helium Light Bands, one HLB measuring about 0.000011 inches (280 nm). Accuracies of 1 to 3 HLB are typical. Though flatness is the most common goal of lapping, the process is also used to obtain other configurations such as a concave or convex surface.
- Diamond lapping is most appropriate for ceramic machining or finishing projects that require edge-to-edge flatness; sublight band (11 millionths of an inch) results are routine.
- When there is a requirement to lap very small specimens (from 3″ down to a few millimetres), a lapping jig can be used to hold the material while it is lapped.
Although some of the terminology may be esoteric, grinding machines are a useful and important part of industrial operations. Comment below with thoughts and opinions.
