The minting press
The press that mints the coins is an original Dutrannoit from 1910. The technique of this friction press is basically rather simple.
A 380V traction engine keeps two flywheels in a constant rotation speed. Between these two wheels you find the horizontal friction wheel. Both flywheels are attached to a shaft that can be moved back and forth. As soon as the left or right flywheel is pressed against the friction wheel, the screw spindle turns clockwise or counter clockwise and the buffer block moves up or down. The screw movement downward gives a very big momentum and this is what results in the powerful blow on the work.
The power of the blow determines the quality of the coin. With the Dutrannoit press this means a blow of 120 tons. To give an idea: comparable to dropping a pile of 66 Audi A6´s. The power suffices to momentarily melt the metal. The coin’s material ‘flows’ into the upper and lower stamps.
In a regular production process coins are minted incessantly into a strip of metal. Next a seperate machine die cuts the round coins out of this strip.
We however mint our coins in one go. Which means the stamps are put into a ring which is layed in a 3mm thick disc with a slightly smaller diameter than the coin. This way the metal flows between the stamps and the sides until the ring stops it. After every blow the coin is stuck in the ring and has to be tapped out with a hard plastic punch.
As the upper stamp has to exactly fall into the ring, this method is somewhat more critical than die cutting out of a strip. The result however is an invariably perfectly positioned coin.
For the connoisseurs: all our coins are ‘Proof’quality. That is: the stamps and rondels are polished and the coins are minted with a minimum power of a 100 tons. ‘Proof’ is the highest possible quality.
Due to the extra brilliance, the image in Proof coins is extremely beautiful and sharp, but also very vulnerable. In the polished parts even the smallest scratches are instantly visible. Also the grease of our skins has immediate effect on the metal. That is why these coins should be handled with gloved hands only. To prevent damage all our coins are instantly individually packed in capsules.