Mass finishing is a terminology used to define the procedure of deburring, cutting, smoothing, polishing, cleaning and separating of parts as a group. This method involves the loading of parts to be finished into finishing machines like the tumbling barrels, vibratory machines and centrifugal barrel machines. Along with the parts, finishing media and/ or finishing compounds can also be loaded with or without water. Once the finishing machines starts execution, the parts graze alongside the media at the same time as being suspended in the finishing compounds. The media and compounds have coarse properties which cause the excess metal (or any other material with which the parts are made) to be abraded away.
The method of mass finishing might use tumbling machines that are barrels which are made to spin or vibratory machines which are tubs that vibrate at very high speeds with short strokes. The finishing media used may perhaps be natural media like the corn cob media and walnut shell media or non-natural media like plastic deburring media and ceramic media. While natural media supply soft abrasive action on the parts, the artificial media are used for intermediate to heavy deburring. Plastic media being lighter compared to ceramic media are used with delicate and fragile parts while the ceramic media is used with heavy loads that necessitate cutting. They come in all sorts of shapes to deal with different sizes and patterns in the parts being completed like conical, pyramidal, cylindrical, triangular and so on.
Finishing compounds are used in the mass finishing procedure to increase media effectiveness. They give further abrasive property and more cutting power. They inhibit glaze formation in the loads so that the media can work better on the parts. These compounds could have alkaline or acidic properties and come in the liquid, powdered or cream forms. When cleaning of parts is needed during the mass finishing, compounds come in very handy. They are good cleaning agents that can degrease, de-scale and de-oxidize. They can also be used to impart properties like anti-rust and anti-corrosion in the parts by using certain chemicals especially for this purpose.
Centrifugal barrel machines are finishing machinery used in finishing of parts. They characteristically have one or more barrels mounted on turrets. These barrels are prepared to rotate at very high speeds so that the principle of centrifugal force comes into play within the barrels. The load within the barrels is thrown to the walls of the barrel because of the centrifugal force that acts on them at the barrel center. The parts and media that have been put together thus rub with each other constantly at a very high rate of speed producing the preferred deburring and cutting action.
The centrifugal barrel machines take less time to finish parts as compared to customary barrels or vibratory machines. They have safety latches to keep the loads safely inside when rotating. They are easy to load and unload. Centrifugal barrel machines come in different capacities, different horse power for motors, electrical powers and shipping weights to suit different finishing operations.
