


1993
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®.
2006
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.
2008
Small processable pieces of leather
The technical scale installation produced the first usable and processable pieces of leather.
2009
Patent registered
The Cleantan® patent was registered by Manfred Renner, the current chairman of Cleantan®, Prof. Eckhard Weidner and Helmut Geihsler.
2012
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
Present
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.