Innovative Coinage Concepts
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INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 INNOVATIVE COINAGE CONCEPTS: FOR WHAT DOING? SEEN FROM A TECHNICAL POINT OF VIEW hen the Product Development and Marketing Department of a Mint begin to start their brainstorming on possible new products, that “ have to be so appealing, attractive, W innovative and “jamais vu ”, it is well know that usually, the Production Department starts becoming headaches. Each technician in this room knows what I am talking about! However, in this paper, I will try to illustrate through an non-exhaustive list what kind of innovations have been achieved in the last past years, and what were the difficulties faced, the limits that had been pushed out to create these innovations, and finally put on the market as “ innovative coinage concepts”. In the classical numismatics field, circulation or collector coins are understood to be: 1-round 2-flat 3-light and small 4-in one piece 5-in a limited range of metals 6-only metallic 7-in a limited range of colours 8-in a limited range of finishes What we can call the 8 classical rules. However, as the number of products grove rapidly in the last 20 years, the Mints of the world have rapidly seen that there is a real challenge in introducing innovative numismatic products ( the so called Collectors’ Coins) in their classical product range, as it is a window on their company showing values like for instance: -modernity -fashion spirit -technical know how or engineering capacity which are clearly aimed to be sales arguments and boosters for the turn-over. Therefore, Marketing people and Technical people began to sit together and state that a collector coin can be more than a copy of a circulating coin, and that there is room for creative designs and innovative techniques. Nowadays, although a coin remains a mean of payment by carrying a face value, it DOES NOT anymore have to follow the above mentioned 8 classical rules. PASCAL RENCKER Page 1/14 INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 However, there are some difficulties ahead, for one who wants to get a rid of these specifications, and this is illustrated hereunder: 1- COINS DO NOT HAVE TO BE ROUND: Example 1: Poland 2003 Rectangle Silver Coin “Famous Painters Series” Example 2: Slovakia 2003 Square Gold and Palladium Coin “10th anniversary of the Republic” Example 3: Slovakia 2001 Triangle Silver and Gold Coin “New Millenium” Example 4: China 2002 Fan-shaped Gold Coin “Year of the Horse” Example 5: The extreme: Nauru 2002 Europa-form Silver Coin “Euro introduction” PASCAL RENCKER Page 2/14 INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 In the case of non-round coins, from the simple rectangle to the complex shape, the problems occurring are usually: - blank-ring interval not regular : gives different pressures while striking and therefore early break of dies - blank profile not adapted : edges not complete, some reliefs not completely struck. The main trouble appears in the corners, where metal has to be placed first in the early pressure stage, while the flanks come out in the end; requires a special profile of the blank. The more the corners are sharp, the more difficult it is to get a completely struck coin, even in multi-strike. - Coin is struck with irregular rim: the rim’s width is varying because of geometrical unfitting between dies and ring ; needs devices for fine check of the slack between dies and ring and micrometric moving. - Special shapes like the Nauru coin requires high precision electro-erosion process for ring and dies. Depending on the design, sometimes a strike-and-cut process can be used, but for adapted forms and very thin materials that can then be used in the form of polished prepared silver coils for instance. 2- COINS DO NOT HAVE TO BE FLAT: Example 1: France 2001 Wave formed Gold and Silver “Ultimate Franc by Starck” The main troubles we experienced at Monnaie de Paris for the wavy form of the Ultimate Franc are directly linked to the curvatures the coin design requires: - Early break of the dies due to a very slight difference in the 3D complex form of the wave of the upper die compared to the lower one. This brought a squeezing point which concentrated the efforts leading to the break, always at the same point. The solution has been found in mounting the dies in the way which respects the natural flow of metal, in following the wave, and feeding the blank accordingly. - The finish of the coin was irregular, and the more unacceptable that the coin had no further stage of treatment (lacquer or protective capsule). The blanks have therefore been prepared in a special way, with deep degreasing and etching, followed by glass balls process. - Insculpation had to be done on the edges after striking, what means rolling an uneven 3D-form through the edge lettering machine with very poor relief. The coin refused to engage itself, and had a tendency to skid like a wheel. When this happened, the coin turned into a reject. Special holding material and feeder allowed finally a successful insculpation on a big scale. PASCAL RENCKER Page 3/14 INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 - Uncomplete edge/ outer rim, on the side of the lower point of the wave. This was due to a lack of metal on the point where the blank had its last forming, leaving an edge slightly turned upwards. Here again, a special profile of the blank was found necessary. Example 2: Congo 2002 Relief and hollow combined Silver Coin “Polaris” Obverse In this case, the originality is that the classical lettering in relief is combined with the hollow triangles, rather deep, the bigger ones being at places α,β,γ, and ξ . - When finish of coin requested is proof, it becomes difficult to have the combination of both relief and hollow patterns. A special die polishing procedure is here certainly required, giving the mirror surface and saving the edges of the geometrical triangle forms. This can lead to others designs based on the same idea, even with deeper patterns in using a “piéfort” blank for instance. Example 3: Hungary 2002 Hollow with screw compartment Base metal Coin “Message-Communication” Coin closed, Reverse - This interesting BU coin of 1000 Forint in CopperZinc is in two parts, the obverse being screwed to the reverse and creating a small compartment while closed. - The idea in itself is not new, as some prototypes appeared as soon as in the 19th century, but these coins were only single specimens. - The issue limit of this coin being as much as 15 000 units, the fabrication process needed to be automatized to keep the costs acceptable. - The question is then: how to mint without damaging the hollow, or how to hollow without destroying the engraving, even if not a proof surface. PASCAL RENCKER Page 4/14 INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 3- COINS DO NOT HAVE TO BE LIGHT AND SMALL: Example 1: Australia 2000 1 kg Silver Coin “Sydney Olympics” Example 2: France 2003 1 kg Silver Coin “First anniversary of the Euro” Example 3: China 2002 1 kg Silver and Gold Coin “Jubilee of Panda Series” Example 4: Fiji Islands 2004 project of a 2 kg Silver Coin “Battle of Trafalgar” In these 4 examples, the same basic problems were faced by the producers: - How to design the 1 kg blank so that the result will be a Proof Coin? On these large blanks, around 100 / 110 mm diameter, the surface of the blank is so important that the rolling mills specific forms and stripes still appear under the tribo-finished upper layer: the outcome is then undulating, wavy uneven proof field, and unidirectional stripes, not compatible with the Proof appellation. - To reduce these consequences, the blank usually goes through different phases of preparation, which are depending on the press used: in general, hardness should not be too low (which is not easy with a 999 silver), and the blank should not be polished, as it reinforces the defects, but experimented with an adapted brush-finish. PASCAL RENCKER Page 5/14 INNOVATIVE COINAGE CONCEPTS SESSION MDC San Francisco / March 2004 17/01/2004 - The profile of the blank has to be adapted: here, no way to work on the rim, as there is no rim, but, depending on the Mints, a 45 ° angle on edge, or a rounded corner. And before this, the cut diameter should be significantly bigger than the finished blank diameter, to avoid the disturbing “fall” on the outer part of the profile, which creates then un-complete outside engravings on the struck coin. - One should also avoid what we at Monnaie de Paris have experienced, which is the deformation of the original model : as the Europa coin was declined is several different coins in a complete range from 37 down to 22 mm, only one reference obverse model was created, in 90 mm diameter. Therefore, we had to enlarge this reference model, in order to use it for the reducing machine with a minimum coefficient of 2, what means a 200 diameter for the new model, which contained the inherent distorsions due to enlargement process. - The australian coin has on the top of that to deal with the problem of pad printing on large/heavy pieces, and the chinese coin with the specific problem of the 2 golden cameos, not easy to carry out on such very big products, as gilding lines are ususally designed to process much smaller pieces.