Apr 8, 2011

Sand Paper and Stone Polishing

Panel consists of Doug Bowers, Mark Herrald, Bob Smith and Wally Clevenger.
Mark presented a slide show on micro finishing, He has the micro-finishing head installed in
his plant in Des Moines. He commented, there are some advantages to this process such as
the roller oscillates and the paper is indexed, always providing a fresh surface for polishing.
For copper polishing, we are using a 15- micron lapping film and a 9-micron micro-finishing
A lubricant is used to keep the paper from building up. Estimated cost is approximately $1.83
for an 84-inch cylinder. The head can be retrofitted to most any existing polishing machine.
Heads with wider paper can reduce polishing time significantly.
Question –How much material do you remove and do you have trouble at the ends of the
Answer – First we were concerned about the dog bone on the ends of the cylinder. We go
back and forth extra times on each end to remove the buildup of copper and then we continue
to polish the rest of the cylinder. The first pass we get rid of nodules the second we
achieve the finish.
Question –Are polishing scratches smaller or larger than with stone polishing?
Answer – About the same.

Question –What is the cylinder roughness?
Answer – .05 to .06 RA and .25 to .30 RZ. Variance from end to end was .02 RZ.
Question – Did you find that with the micro finishing paper film you have less streaking on
Answer – We do not have scumming or toning. It appears that we have less streaking too.
Question –Do you have to change the 15 and 9 micron paper between polishers?
Answer – Yes, you would have to have two heads which would polish at the same time to
keep from having to change papers. This would reduce the time by 60 percen

1 comment:

  1. hello!!!

    I work in a new factory where we produce rotogravure cylinders.
    We have a polish machine from daetwyler with two heads - stones (1500 and 2500) and two heads - papers (20μm polishing film and 12μm laping film).

    We would like to have a roughness 0,5 and 0,6 in copper but we dont know how to make this.
    Do you have any idea how to make this rougness, kg per stone, rpm per stone, how many passes, mm/rpm per stone e.t.c?