Centrifugal Disc Finishing

The centrifugal disc process is a high-energy mass finishing process. The basic design is a vertical cylinder with side walls that are stationary. The top of the cylinder is open. The bottom of the cylinder is formed by a disc that is driven to rotate at a high speed. Media, compound, and parts are contained in the cylinder. As the disc rotates with peripheral speeds of up to 10.2 m/s (2000 ft/min), the mass within the container is accelerated outward and then upward against the stationary side walls of the container, which act as a brake. The media and parts rise to the top of the load and then flow in toward the center and back down to the disc.

The action achieved in the centrifugal disc machine, shown in Fig. 6, is substantially faster than in vibratory equipment because of the centrifugal forces of as much as ten times gravity pressing abrasive media against components. Process cycle times are up to ^ those of vibratory processing. The short process cycles result in reduced floor space requirements in the finishing department, increased versatility, and less work in progress. As with vibratory equipment, parts can be readily inspected during the process cycle and variable speed can occasionally combine deburring with a final, more gentle surface refinement operation. The faster process speeds create a much greater rate of media wear and increase demands on the compound solution and its flow rate.

Fig. 6 Centrifugal disc machine

Centrifugal disc equipment is available with capacities ranging from 0.04 to 0.6 m3 (1.5 to 20 ft3). This equipment is easily automated. The load is emptied through a door in the side of the container through which parts and media can be fed, or by tilting the whole bowl through 180° to dump the load. Subsequent separation, classification, washing systems, and the return of media to the container for the next operation are similar to those techniques used with tub vibratory machines.

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