Contributing Editor: Dave Davidson, Deburring/Finishing Technologist 509.230.6821 | dryfinish@gmail.com | https://about.me/dave.davidson
If you have parts that need edge or surface finishing improvement and would like to have FREE sample part processing and a quotation developed for finishing the parts please contact Dave Davidson at dryfinish@gmail.com I can also be reached at 509.230.6821. Information about equipment for bringing Centrifugal Iso-Finishing capability to your facility is also available…
Although more widely known as techniques for automating the deburring and finishing of metal parts a wide variety of plastic parts and components can also be finished with mass finishing technology. This technology can be used to produce edge contour, smooth, blend in partings lines and on some plastic materials produce polished reflective surfaces of exceptional quality. See some examples below:
Resin treated fabric part has been processed to remove loose fabric strands and polished to improve surface roughness in this bearing retainer.
(Above and below) Deflashing processes with high energy centrifugal finishing equipment and abrasive media are used to replace hand-deburr operations on many rubber and plastic parts
In many applications, high-speed centrifugal isotropic finishing can be used in conjunction with dry process polishing media for final polishing operations. See an example of this equipment below
Enter Above is shown a Model HZ-60 Centrifugal Iso-Finishing machine widely used in the dental, medical and aerospace industries for developing polished low-micro-inch surfaces
Centrifugal Iso-Finishing Technology
Centrifugal barrel finishing (CBF) is a high-energy finishing method, which has come into widespread acceptance in the last few years. A long list of important centrifugal iso-finishing applications has been developed in the last few years for the aerospace, medical, high-performance motor-sports, precision machined component and additive manufacturing industries.
Similar in some respects to barrel finishing, in that a drum-type container is partially filled with media and set in motion to create a sliding action of the contents, CBF is different from other finishing methods in some significant ways. Among these are the high pressures developed in terms of media contact with parts, the unique sliding action induced by rotational and centrifugal forces, and accelerated abrading or finishing action. As is true with other high energy processes, because time cycles are much abbreviated, surface finishes can be developed in minutes, which might tie up conventional equipment for many hours.
Centrifugal Barrel Finishing principles – high-intensity finishing is performed with barrels mounted on the periphery of a turret. The turret rotates providing the bulk of the centrifugal action, the barrels counter-rotate to provide the sliding abrasive action on parts.
The principle behind CBF is relatively straightforward. Opposing barrels or drums are positioned circumferentially on a turret. (Most systems have either two or four barrels mounted on the turret; some manufacturers favor a vertical and others a horizontal orientation for the turret.) As the turret rotates at high speed, the barrels are counter-rotated, creating very high G-forces or pressures, as well as considerable media sliding action within the drums. Pressures as high as 50 Gs have been claimed for some equipment. The more standard equipment types range in size from 1 ft3 (30 L) to 10 ft3, although much larger equipment has been built for some applications.
Media used in these types of processes tend to be a great deal smaller than the common sizes chosen for the barrel and vibratory processes. The smaller media, in such a high-pressure environment, are capable of performing much more work than would be the case in lower energy equipment. They also enhance access to all areas of the part and contribute to the ability of the equipment to develop very fine finishes. In addition to the ability to produce meaningful surface finish effects rapidly, and to produce fine finishes, CBF has the ability to impart compressive stress into critical parts that require extended metal fatigue resistance. Small and more delicate parts can also be processed with confidence, as the unique sliding action of the process seems to hold parts in position relative to each other, and there is generally little difficulty experienced with part impingement. Dry process media can be used in certain types of equipment and is used for light deburring, polishing, and producing very refined isotropic super-finishes.
AUTHOR BIOGRAPHY – David A. Davidson, [dryfinish@gmail.com]
Mr. Davidson is a deburring/surface finishing specialist and consultant. He has contributed technical articles to Metal Finishing and other technical and trade publications and is the author of the Mass Finishing section in the current Metal Finishing Guidebook and Directory. He has also written and lectured extensively for the Society of Manufacturing Engineers, Society of Plastics Engineers, American Electroplaters and Surface Finishers Association and the Mass Finishing Job Shops Association. Mr. Davidson’s specialty is finishing process and finishing product development.
For additional information on contract deburring and finishing services with the Centrifugal Iso-Finishing method visit our web-page on Contract Finishing.
SEE: https://dryfinish.wordpress.com/2016/08/05/contract-finishing-and-free-sample-part-processing-for-centrifugal-isotropic-finishing-and-polishing/
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