D21H 23/28
Addition before the dryer section
Official title: Addition before the dryer section, e.g. at the wet end or press section
D21H23/28 (Addition before the dryer section) appears on 79 US grants and 63 published applications in this corpus.
Search patents in D21H- Granted patents
- 79
- Published applications
- 63
- Assignees
- 71
- Inventors
- 194
- Latest grant
- 12 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 2 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 2 | 0 |
| 1989 | 2 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 2 | 0 |
| 1993 | 1 | 0 |
| 1994 | 3 | 0 |
| 1995 | 3 | 0 |
| 1996 | 3 | 0 |
| 1997 | 1 | 0 |
| 1998 | 5 | 0 |
| 1999 | 5 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 6 | 4 |
| 2003 | 1 | 7 |
| 2004 | 2 | 4 |
| 2005 | 3 | 11 |
| 2006 | 2 | 2 |
| 2007 | 3 | 1 |
| 2008 | 1 | 3 |
| 2009 | 0 | 1 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 1 | 3 |
| 2014 | 1 | 0 |
| 2015 | 0 | 0 |
| 2016 | 1 | 2 |
| 2017 | 2 | 2 |
| 2018 | 1 | 6 |
| 2019 | 3 | 2 |
| 2020 | 1 | 1 |
| 2021 | 5 | 5 |
| 2022 | 3 | 2 |
| 2023 | 2 | 4 |
| 2024 | 2 | 2 |
| 2025 | 2 | 1 |
| 2026 | 1 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Method for manufacturing a barrier film comprising highly refined cellulose12 May 2026US 12,624,501 B2Stora Enso OYJ
- Method of making a cellulose film comprising microfibrillated cellulose30 Sep 2025US 12,428,530 B2Stora Enso OYJ
- Surface enhanced pulp fibers at a substrate surface15 Jul 2025US 12,359,375 B2Domtar Paper Company, LLC
- Paperboard and a method of producing a paperboard9 Apr 2024US 11,952,718 B2Stora Enso OYJ
- Water-dispersible composite structure and method of producing the same30 Jan 2024US 11,885,072 B2Paptic Oy
- In-line application of dispersion barrier22 May 2025US 2025/0163648 A1Brown LLC
- Method for manufacturing a barrier film comprising highly refined cellulose11 Jul 2024US 2024/0229358 A9Stora Enso OYJ
- Method for manufacturing a barrier film comprising highly refined cellulose25 Apr 2024US 2024/0133118 A1Stora Enso OYJ
- Strength improvement via sprayboom application5 Oct 2023US 2023/0313467 A1Ecolab USA Inc.
- Water-dispersible composite structure and method of producing the same9 Mar 2023US 2023/0074973 A1Paptic Oy
Most cited
By later US patents
- Process for making soft, strong cellulosic sheet and products made thereby136US 4,795,530 AKimberly-Clark Corporation · 1989
- Crosslinked cellulose products and method for their preparation114US 5,225,047 AWeyerhaeuser Company · 1993
- Soft tissue paper containing an oil and a polyhydroxy compound92US 5,575,891 AThe Procter & Gamble Company · 1996
- Hydrophilic cellulose product and method of its manufacture72US 4,853,086 AWeyerhaeuser Company · 1989
- Apparatus for crosslinking individualized cellulose fibers48US 5,437,418 AWeyerhaeuser Company · 1995