The exceptional does not happen
in an even, ordinary way.
Johann Wolfgang von Goethe (1749-1832)

The high point and a new beginning

At the end of the 1980s, the rapid growth of ultrafilter made an expansion of the capital base necessary. Dirk G. Kronsbein looked for and found the right partner, and it in turn justified its commitment to the “newcomer” (who only had limited security at his disposal in banking terms) specifically because of the personality of Dirk G. Kronsbein: “A clear decision for a strategic concept sustained by a visionary entrepreneurial personality,” as the Office Director of the investment company 3i later emphasised during an interview. In the venture capital business, you also need to have “a feel for winners. Mr Kronsbein was just such a case. A sales genius, a man with the right intuition and perseverance.”

With the help of an equity injection, ploughing the free cash flow back into the business, venture capital and bank loans, over the next few years Kronsbein succeeded in reaching a turnover of EUR 120 million with around 900 employees worldwide. From the 1990s, ultrafilter was the market leader in Europe, with production sites in Germany, Spain and the US, as well as 34 further overseas companies in the field of sales and service. Dirk G. Kronsbein obtained a fair few of his entrepreneurial incentives at the annual World Economic Forum (WEF) in Davos, where he was also able to make numerous contacts and friendships.

Because the rapid pace of growth repeatedly led once again to the question of financing, in 1998 Kronsbein decided to convert the GmbH into an AG. This was a first step towards a stock market listing. The thought of grappling with an emancipated Supervisory Board from that point onwards “really did not come easily” to the full-blooded entrepreneur. Yet together the managers prepared ultrafilter for this arena. When everything was ready, the major bank accompanying them scrapped their stock market listing, pointing out the way the market was developing. It was a shock, but Dirk G. Kronsbein kept his nerve and held on to the reins even in this situation. At a “controlled auction” in spring 2002, he sold ultrafilter to the US-based Donaldson Company Inc. and thus ensured its growth finance and the continuity of his life’s work. His son Dean initially took over the management of the European division. Four years later he left the company and once again secured the company name “ultrafilter”, which was no longer being used by Donaldson. Today Dean Kronsbein’s ultrafilter GmbH, based in Hilden, is one of the most innovative manufacturers of high performance filters and treatment components for compressed air, technical gases and liquids.