Electroforming Problem
We are in the currency printing industry and we electroform our printing plates. We are having a problem with parting electroforms from the mandrels. Do you have any suggestions for solving this problem?
Q: We are in the currency printing industry and we electroform our printing plates. We are having a problem with parting electroforms from the mandrels. We use sodium dichromate as the parting agent. Do you have any suggestions for solving this problem? We use a nickel sulfate bath. K. A.
A: You don’t give me much information to work with but I would start out by asking whether sodium dichromate has worked well for you in the past. If it has worked well in the past than you have to try to figure out what is different now. I would look at the concentration of the dichromate solution as a starter. A concentration of approximately 0.5 ounce per gallon of water is usually what is recommended. I would also investigate your nickel plating solution to determine if it is at the right concentrations. Perhaps you have too much or too little of the anti-stress agent in the bath?
I also recommend that you get a copy of the latest ASTM Specification, B832-93 (2003), www.astm.org, and compare your process to the recommendations given in Specification.
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