ALEXANDRIA, Va., Feb. 3 -- United States Patent no. 12,539,478, issued on Feb. 3, was assigned to Ahlstrom Oyj (Espoo, Finland).
"Filter medium and a use thereof" was invented by Anne Viskari (Lempaala, Finland) and Jan Kaukopaasi (Tampere, Finland).
According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention relates to a filter medium being at least formed of a pre-filter substrate laminated with a fine-filter substrate by means of a third binder, wherein the pre-filter substrate comprises synthetic fibers and a first binder, the pre-filter substrate working as a combined surface and depth filter, and the fine-filter substrate comprises at least a second binder and one of synthetic fibers and inorgan...