Coins intended for circulation in collection quality are part of the standard programme of the State Mint in Berlin. When it came to the production of euro coins, the question was: pre-assembled bimetal blanks or assembly and minting in one single processing step? The decision was clear.
Minting and assembly in one single processing step has advantages across the board:
- Economic use of the equipment
All processing steps are carried out in one step on one machine. No additional press is used for assembly.
- Longer operational life of the die
The softer the blank, the lower the wear and the related costs. Unassembled blanks have a core hardness of about 86 HV30 compared to about 114 HV30 in case of pre-assembled blanks.
- Better coin image
The softer the material, the better the flow properties in the coining die. Plus, there is less force required.
- Perfect blanks
Separate polishing of ring and core is better and easier technically than polishing pre-assembled blanks. Without a separate pre-assembly process, the risk of resulting impurities or damage is also removed. The blanks remain flawless.
A perfect minting result requires the most precise feeding and an optimal tool system
For this task, the table medal press (TMP) by Sack & Kiesselbach was equipped with a special transfer system for bimetal coins.
The automated material feeding is the key to the successful minting and assembly in one single processing step. Ring and core are fed-in separately and precisely placed one into the other by vacuum grippers. This task is far from trivial. For example, based on its weight the ring offers only a small suction surface and requires a high degree of reliability of the system.
„Changing to mining and assembly in one single processing step resulted not only in more economic efficiency but also led to an improvement in product quality.“
Jürgen Stolz, Managing Director, State Mint Berlin
The table medal press (TMP) is available with various extensions for both standard and bimetal coins and makes flexible production possible. Switching formats only takes about 15 minutes.
Your contact for system consultation
Managing Director and machine technology
Sack & Kiesselbach
Langster Str. 9
D-40668 Meerbusch (Langst-Kierst)
Tel: +49-2150-75 62 - 141
Fax:+49-2150-75 62 - 100