The small Pacific island state of Niue is known among numismatists as publisher of unusual coin creations. The current “coin” is shaped like a sphere and shows a historical map indicating the seven new wonders of the world with crystals.

The renowned Mint of Poland undertook the realisation of this demanding project.

A technical challenge

Thanks to modern software like ArtCAM, the spherical projection of the design and the following laser engraving are not a big problem nowadays. However, imprinting the entire surface of a round body and designing suitable tools required the development of completely new and innovative solutions. It took the experienced experts of the Mint of Poland several approaches to solutions and numerous practical trials to achieve the perfect final result.

„We used a press by Sack & Kiesselbach for this project, because we wanted to have the greatest control possible over all parameters of the minting process.“

Siemowit Kalukiewicz, Chief Operating Officer, Mint of Poland

Engineering and skilled precision work bring the desired result

The perfect result is made possible through the precise interaction of tool and press. The spherical coin is produced on an upstroke hobbing press by Sack & Kiesselbach via manual feeding operation. The advantages:

  • Precise control of the press stroke.
  • The hydraulic press works power-controlled, displacement-controlled and time-controlled and makes control of the entire minting process in the hundredth millimetre range possible.
  • Multiple pressing in the closed tool.
  • Makes an optimal material flow during the minting process possible.
  • High-precision tool.
  • The tool segments are closed and supported via hydraulic pre-tension.

Your contact for System consultation

Markus Schlein
Managing Director and machine technology

Sack & Kiesselbach
Maschinenfabrik GmbH
Langster Str. 9
D-40668 Meerbusch (Langst-Kierst)

Tel: +49-2150-75 62 - 141
Fax:+49-2150-75 62 - 100

Siemowit Kalukiewicz
COO and Tool technology

Mint of Poland
11, Waliców Str.
PL-00-851 Warsaw

Tel: +48-22-656 42 67
Fax: +48-22-656 4040