User Guide
Abrasive Belt Sequence for Flat Polishing
This chart indicates the finish produced by various heads on a
flat polishing line. There are 12 heads in the line. Heads 1
through 4 use grade 100 aluminum oxide. Heads 5 through 8
use grade 150 aluminum oxide. Heads 9 through 12 use grade
150 silicon carbide with oil on the 11th head and grease on the
12th head.
The belts are moved down the line at one-half-belt life to
present a more consistent set of conditions than possible when
using a belt for its entire life on one station. This system
produces more uniform stock removal and finish than a system
using twice as many grade sizes on the same number of heads.
The Half-Belt-Life Principle
Following is an example of the half-belt-life principle at work.
Atypical grade 100 aluminum oxide paper belt will produce a
finish reading of about 90 when new . . . and 45 when used.
If it is moved at half-life, we have the effect of two diff e r e n t
belts. The first produces 90 to 60 readings and the second,
60 to 45 readings.
Flat Polishing Considerations
Three good points to keep in mind in a flat polishing operation
are the finish re q u i re m e n t s, the amount of s t o ck re m ova l
needed to clean up pits and defects, and p roduction rat e
r e q u i r e d .
Flat Polishing Finish Require m e n t s
Industry experience has shown that different plating systems
require different finishes.
This chart shows approximate finish requirements in the
automotive industry. Generally speaking, plating systems which
employ less nickel or copper have less covering power, and
require finer finishes on the bare metal.
Flat Polishing Stock Removal Test Pro c e d u re
Production people need to know just how much stock removal is
needed to clean up pits and defects. The best way to determine
this is to run a test. For example, weigh the raw sheet before
grinding. Then grind it with a succession of passes, carefully
inspecting it to determine when all defects have been removed.
At this point, weigh the sheet and figure stock removal in
ounces per square foot.