Issued Patents 1997
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5658640 | Electret filter media having an undulated surface | David A. Olson | 1997-08-19 |
| 5658641 | Filter media haing an undulated surface | David A. Olson | 1997-08-19 |
| 5643507 | Filter media having an undulated surface | David A. Olson | 1997-07-01 |
| 5641555 | Cup-shaped filtration mask having an undulated surface | David A. Olson | 1997-06-24 |