Mechanical Finishing Q&A: Multiple Grain Abrasives for Long Life and Consistent Finishing
Q. We are using a 3-inch by 90-inch, X-weight cloth back, 120-grit aluminum oxide belt on our robotic polishing system. The excessive belt wear creates uneven finishes and productivity loss because of constant abrasive belt changes. What solution do you recommend?
A. This happens often in high production robotic and automated polishing. Increasing the belt length and long-lasting abrasive grains, such as zirconium or ceramics, will increase belt life. If the aluminum oxide or silicon carbide must be used because of its finishing capabilities, then a multiple-grain belt is the solution.
A multiple-grain abrasive belt construction consists of layered abrasive grains with various thicknesses on cloth, polyester or film backing. These multiple layers can be randomly stacked, formed in a bubble or layered as a pyramid, depending on the coated abrasive manufacturer.
The multiple layers appear to be coarser than the individual abrasive grain size they are comprised of, but they give the same finish as the individual grains themselves.
We have had excellent success reducing robotic systems with daily belt changes to weekly belt changes. Consistent finish with extended life is the biggest advantage.
Originally published in the April 2016 issue.
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