Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4673782 | Process and apparatus for microwave melting solidified gel masses, in particular of photographic emulsions | Gunther Koepke, Hans Frenken | 1987-06-16 |
| 4427645 | Process for the preparation of solutions from environmentally noxious substances | Hans Frenken, Karl D. Voss | 1984-01-24 |
| 4341642 | Process and an apparatus for continuously filtering liquids | Gunther Koepke, Hans Frenken | 1982-07-27 |