The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 2026
Filed:
Oct. 07, 2021
Ahlstrom Oyj, Helsinki, FI;
Harri Niemelä, Kouvola, FI;
Hanna Rahiala, Kotka, FI;
Rami Haakana, Kotka, FI;
Juha Sorvari, Kotka, FI;
Andrea Corradi, Turin, IT;
Andrea Grosso, Turin, IT;
Andrea Frillici, Sassoferrato, IT;
Francesco Stopponi, Fabriano, IT;
AHLSTROM OYJ, Helsinki, FI;
Abstract
A filter sheet media () for air/gas filtering applications fulfilling the criteria of standard EN779:2012 class M6 filter media, the filter sheet media () comprises: a first group of glass fibers () having a fiber diameter in a range of greater or equal to 6 μm up to 20 μm; a second group of glass fibers () having a fiber diameter in a range of 0.2 μm to less than 6 μm; a binder (); the second group of glass fibers () have a fiber distribution gradient over the thickness () of the filter sheet media () so that the second group of glass fibers () are distributed through the thickness () of the filter sheet media (), the filter sheet media () having more second group of glass fibers () near the first surface () than the second surface (). Also disclosed is a method for manufacturing.