First Patent

Prof. Eckhard Weidner, head of Fraunhofer UMSICHT, and Helmut Geihsler, professional tanner, registered a patent for a technology that later was developed into Cleantan®.


Development of the actual Cleantan® technology

The 1993 patent is developed into Cleantan®. In the lab scale installation, leather samples of the size of a small coin were tanned, proving that the Cleantan® technology actually works.


Small processable pieces of leather

The technical scale installation produced the first usable and processable pieces of leather.


Patent registered

The Cleantan® patent was registered by Manfred Renner, the current chairman of Cleantan®, Prof. Eckhard Weidner and Helmut Geihsler.


Complete hides

The first 500 kg batch of complete hides was tanned in this pre-industrial scale tanning installation at the Fraunhofer lab in Oberhausen, showing that the Cleantan® technology is fit for industrial quantities.

Innovation Award Cologne 2012
San Jordi Award 2012


Available for the market

The Cleantan® technology is available as a license on industrial scale for any leather tanning company, ready to implement in existing plant infrastructures.