by Ursula Kampmann
translated by Almuth Klingner
June 28, 2018 – While, in Panmunjom, Kim Jong-un and Moon Jea-in started a new chapter in the history of Korea, around 250 participants met in Seoul for the 30th Mint Directors Conference between April 22 and 26, 2018. Members of the mint industry from 36 nations were present, coming from central banks and mints, from suppliers, direct marketing companies, the media and coin conventions.
The sub-committees’ work and research findings
Over the last few years, the Technical Committee has been split up into numerous sub-committees who, together with the supply industry, are looking for solutions to specific problems. Here are some of the most important results of the ongoing research:
Spending time together is just as important as the presentations. Here, what was heard earlier is being discussed and “digested”. Photo: MDC 2018.
Coining with computer simulation
The Japan Mint has been looking for some time now into the possibilities of computer analysis when it comes to predicting the ideal characteristics of a die without trial strikes, for optimal die life and flawless striking.
In experiments with coins of its own as well as such from foreign mints, the Japan Mint has proven that the die life can be doubled by decreasing the die curvature.
The method has now also been tested with dies from other mints. The Bavarian State Mint (Bayerisches Hauptmünzamt) and the Austrian Mint (Münze Österreich) have provided dies for the study. Especially for the Austrian 2-eurocent coin, the Japanese program found potential for improvement: The die life is likely to be considerably increased by slightly reducing the reverse side’s curvature.
The end of the ugly tarnishing of silver coins
On the occasion of the World Money Fair 2016, the Mint of Poland first introduced its new technology for surface treatment which is able to delay the unsightly tarnishing of gold and silver coins. This method is only one of numerous currently used in the industry.
One sub-committee of the Technical Committee is working on the comparison and evaluation of existing methods for preventing the tarnishing of precious metals. Siemowit Kalukiewicz presented the current state of research, which is far from being finished.
The automation of die polishing
Traditionally, polishing proof dies for coining is an elaborate process, involving lots of manual labor. The United States Mint, likely producing higher circulations of commemorative coins than any other mint in the world, has fully automated this process.
It is the focus of a study seeking to find out if the new process can be applied at other mints.
In a third step, it would then be necessary to find out at which circulation numbers the required technical equipment actually starts becoming economical.
Several mints have provided raw dies for the project. However, there were delays due to US customs. Until now, the new process has only been tried for a Japanese die. So far, the results are not comparable to those of manual polishing. This is probably not due to the method itself, but to the fact that foreign mints’ raw dies do not have the exact same characteristics as US dies. Thus, an adaptation to a larger sample size would be necessary in order to achieve clear results.
The study is being continued.
Laser machining, CNC milling and electrochemical machining in die manufacturing: A comparison
Is there nowadays a method which can replace the conventional hydraulic hobbing of dies? A new sub-committee has been created specifically for answering this question. It includes four mints and three industry partners:
ACSYS, with its Piranha PICO and Orca PICO, represents the laser technology. Lang with its IMPALA stands for CNC milling, and PEMtec with the PEM 800 for electrochemical machining.
A number of characteristics of the different machines were studied, e.g. die quality as regards visual image and detail transfer, safety, environmental sustainability and the ability to incorporate the machine into an existing production line. The costs for the different technologies incurred with small and large runs were naturally also an important factor.
The first comprehensive results are now available. They are too extensive to be presented here in detail, which is why, at this point, we only summarize the conclusions:
- Each of these methods can be used to produce tooling and dies.
- Which one is best depends on a number of factors.
- A lot of further research work is needed in order to optimize the methods.
Therefore, it would be useful to continue the study to collect more data and especially to estimate the final cost. A combination of methods is likely to be most effective.
Which is the most environmentally-friendly method of wastewater treatment? This question shall be answered here. Photo: MDC 2018
A question of sustainability
A large sub-committee featuring twelve mints – including the Mint of Finland, the Münze Österreich, the Royal Canadian Mint, the China Banknote Printing and Minting Co. and the United States Mint – addresses issues of environmental sustainability.
Currently, the research is at the point of identifying the resource consumption during the production of blanks and coins. In Bangkok, the committee had to admit, slightly embarrassed, that it had been unable to determine the amount of water used for the production of a certain number of coins. The question regarding energy, however, could be answered in 2018: To produce one million coins, from blanks to striking, between 1,000 and 2,500 kWh are needed.
Furthermore, three different methods of wastewater treatment were compared:
- Physical-chemical treatment (South Africa)
- Physical-chemical treatment with filtration (Mexico)
- Vacuum Distillation (Münze Österreich)
The most environmentally-friendly method was vacuum distillation, where 97% (!) of the water are recycled – compared to 0% with the physical-chemical method, and 39% with the physical-chemical treatment plus filtration. However, acquisition costs of this system are very high, and the energy consumption is increased significantly.
A new alloy for producing blanks
Poongsan is currently working on a cost-effective alternative silver-colored copper alloy for coin blanks. It is supposed to be at least 25% cheaper than cupronickel, but still have a similar electrical conductivity and be tarnish-resistant.
Poongsan has reported on this research project several times before. On the occasion of the MDC in Korea, Cheol Min Park was happy to announce that the breakthrough had been reached. A new material has been found which is 24,2% cheaper than cupronickel, while presenting a similar color and conductivity at 5.64% ICAS.
For Poongsan, the next step will be to test the material’s minting suitability for mass production.
Mentors for the minting industry
Dr. Prabir De gave a talk about the importance of long-term guidance for young people in the minting industry in order to preserve the knowledge older employees have accumulated over decades. The advantage of external mentors is already being used in many international professions, which is why the MDC as well has decided to provide this opportunity. For starters, Dr. Manfred Matzinger-Leopold, Dr. Mike Gradwell and Dr. Prabi De are available as mentors. The mentoring network is to be expanded; the first summary report on the new program will be presented at the MDC in South Africa in 2020.
In part 4, we introduce a new MDC project. The Customer Task Force seeks to find out what the users expect from a coin.
Part 1 of our articles on the MDC covers the future of cash.
Part 2 is about the different guidelines given out by the MDC.
Here, you get to the website of the MDC 2018.
The MDC2018 was organized by KOMSCO, die Korea Minting, Security Printing & ID Card Operating Corporation.
On this website, you can find out more about KOMSCO.