D21H 27/08
Filter paper
Official title: Filter paper (self-supporting filtering material B01D39/14; making on paper-making machines D21F11/14)
D21H27/08 (Filter paper) appears on 163 US grants and 164 published applications in this corpus.
Search patents in D21H- Granted patents
- 163
- Published applications
- 164
- Assignees
- 136
- Inventors
- 439
- Latest grant
- 14 Jul 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1981 | 3 | 0 |
| 1982 | 2 | 0 |
| 1983 | 1 | 0 |
| 1984 | 4 | 0 |
| 1985 | 2 | 0 |
| 1986 | 0 | 0 |
| 1987 | 5 | 0 |
| 1988 | 2 | 0 |
| 1989 | 2 | 0 |
| 1990 | 3 | 0 |
| 1991 | 3 | 0 |
| 1992 | 4 | 0 |
| 1993 | 1 | 0 |
| 1994 | 0 | 0 |
| 1995 | 3 | 0 |
| 1996 | 8 | 0 |
| 1997 | 3 | 0 |
| 1998 | 5 | 0 |
| 1999 | 3 | 0 |
| 2000 | 5 | 0 |
| 2001 | 2 | 0 |
| 2002 | 6 | 5 |
| 2003 | 4 | 13 |
| 2004 | 5 | 8 |
| 2005 | 5 | 4 |
| 2006 | 1 | 1 |
| 2007 | 3 | 4 |
| 2008 | 2 | 1 |
| 2009 | 1 | 2 |
| 2010 | 0 | 7 |
| 2011 | 0 | 1 |
| 2012 | 4 | 5 |
| 2013 | 2 | 8 |
| 2014 | 3 | 5 |
| 2015 | 4 | 12 |
| 2016 | 4 | 7 |
| 2017 | 4 | 3 |
| 2018 | 5 | 5 |
| 2019 | 4 | 7 |
| 2020 | 8 | 16 |
| 2021 | 6 | 11 |
| 2022 | 7 | 6 |
| 2023 | 8 | 8 |
| 2024 | 6 | 12 |
| 2025 | 8 | 4 |
| 2026 | 2 | 9 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Filter material for air filter and method for producing filter material14 Jul 2026US 12,678,724 B2Hokuetsu Corporation
- Hot extraction paper30 Jun 2026US 12,668,927 B2Mondi AG
- Filter media16 Dec 2025US 12,497,737 B2SWM Holdings US, LLC
- Filter paper for cigarette filters and filter comprising it4 Nov 2025US 12,460,352 B2Miquel Y Costas & Miquel, S.A.
- Filtration apparatus containing graphene oxide membrane26 Aug 2025US 12,397,268 B2Via Separations, Inc.
- Papermaking mat and method for producing paper making mat27 Aug 2026US 2026/0250908 A1Ibiden Co., Ltd.
- Filter material for air filter, and method for manufacturing same25 Jun 2026US 2026/0175152 A1Hokuetsu Corporation
- Filtration apparatus containing graphene oxide membrane25 Jun 2026US 2026/0175179 A1Via Separations, Inc.
- Lyocell fiber with increased tendency to fibrillate11 Jun 2026US 2026/0159995 A1Lenzing Aktiengesellschaft
- Filter wrapper for aerosol generating articles and filters for aerosol generating articles including the same4 Jun 2026US 2026/0150880 A1Kt&G Corporation
Most cited
By later US patents
- Filtration structures of wet laid, bicomponent fiber148US 5,580,459 AHoechst Celanese Corporation · 1996
- Porous filter media and membrane support means89US 4,765,915 AThe Dow Chemical Company · 1988
- Dust filter bag containing nano non-woven tissue87US 6,395,046 B1FiberMark Gessner GmbH & Co. · 2002
- Filter and method of making same76US 4,309,247 AAMF Incorporated · 1982
- Filtration fabric produced by wet laid process66US 4,973,382 AInternational Paper Company · 1990