Media That Stays Sharp
Is there a sharp, preformed ceramic media shape that can reach into tight-radius areas of parts?
Q. Our company produces a cosmetic aluminum fitting. We vibratory finish with a ceramic media to produce a uniform finish. The media do not reach into the tight radius of the part’s external corners, leaving a brighter finish in the unprocessed areas. Is there a sharp, preformed media shape that can reach into these tight radius areas? —M.K.
A. The ¾" × 1" polyester or synthetic plastic wedge (bowtie) works well in processing tight external corner areas.
The plastic wedge is the only preformed media type and shape I’ve found that sharpens as it wears. In contrast, ceramic media may start sharp but round as they wear. Using wedge plastic media is a more stable process than the ceramic process.
Your vibratory process time cycle will have to be increased to allow media to reach into the tight area, however.
When choosing vibratory media, understand the size, shape, starting roughness condition and metallurgical structure of the part.
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