D21C 9/02
Washing
Official title: Washing {; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents}
D21C9/02 (Washing) appears on 373 US grants and 221 published applications in this corpus.
Search patents in D21C- Granted patents
- 373
- Published applications
- 221
- Assignees
- 198
- Inventors
- 702
- Latest grant
- 29 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 3 | 0 |
| 1978 | 6 | 0 |
| 1979 | 5 | 0 |
| 1980 | 5 | 0 |
| 1981 | 6 | 0 |
| 1982 | 2 | 0 |
| 1983 | 2 | 0 |
| 1984 | 4 | 0 |
| 1985 | 13 | 0 |
| 1986 | 9 | 0 |
| 1987 | 7 | 0 |
| 1988 | 10 | 0 |
| 1989 | 13 | 0 |
| 1990 | 13 | 0 |
| 1991 | 12 | 0 |
| 1992 | 5 | 0 |
| 1993 | 9 | 0 |
| 1994 | 5 | 0 |
| 1995 | 10 | 0 |
| 1996 | 15 | 0 |
| 1997 | 12 | 0 |
| 1998 | 14 | 0 |
| 1999 | 9 | 0 |
| 2000 | 10 | 0 |
| 2001 | 9 | 2 |
| 2002 | 7 | 7 |
| 2003 | 7 | 5 |
| 2004 | 3 | 7 |
| 2005 | 4 | 2 |
| 2006 | 3 | 10 |
| 2007 | 3 | 3 |
| 2008 | 2 | 8 |
| 2009 | 2 | 8 |
| 2010 | 3 | 14 |
| 2011 | 7 | 7 |
| 2012 | 12 | 9 |
| 2013 | 5 | 3 |
| 2014 | 13 | 14 |
| 2015 | 6 | 16 |
| 2016 | 8 | 13 |
| 2017 | 11 | 14 |
| 2018 | 9 | 9 |
| 2019 | 4 | 10 |
| 2020 | 4 | 8 |
| 2021 | 12 | 9 |
| 2022 | 4 | 10 |
| 2023 | 5 | 11 |
| 2024 | 12 | 9 |
| 2025 | 14 | 5 |
| 2026 | 3 | 8 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Multi-ply liner with washed NSSC pulp29 Sep 2026US 12,747,539 B2Stora Enso OYJ
- Optimization of chemical consumption in biomass delignification4 Aug 2026US 12,698,589 B2Sixring Inc.
- Method and apparatus for treating mixtures of liquids and solids19 May 2026US 12,630,976 B2Lean Pulp Oy
- Process to optimize brown stock washing unit operations23 Dec 2025US 12,503,814 B2Ecolab USA Inc.
- Fiber wash system and method25 Nov 2025US 12,480,087 B2IntegroEnergy Group, Inc.
- Pulp mixture6 Aug 2026US 2026/0226680 A1SöDra SkogsäGarna Ekonomisk FöRening
- Multi-ply liner with washed nssc pulp30 Jul 2026US 2026/0218457 A1Stora Enso OYJ
- Recycling of release liner glassine and sck into high quality pulp23 Jul 2026US 2026/0210041 A1Upm-Kymmene Corporation
- Process of using non-wood fibers to create paper pulp16 Jul 2026US 2026/0201639 A1
- Method for bleaching cellulose pulp formed from recycled textile material9 Jul 2026US 2026/0193838 A1Valmet Corporation
Most cited
By later US patents
- Control system for controlling a pulp washing system using a neural network controller95US 5,282,131 ABrown and Root Industrial Services, Inc. · 1994
- Use of polymers in the recycled fiber washing/deinking process92US 5,626,718 ABetz Laboratories, Inc. · 1997
- System and method for cleaning, processing, and recycling materials46US 6,238,516 B12001
- Process for treating a slurry of cellulosic material45US 4,046,621 ACanadian International Paper Company · 1977
- Method for steaming comminuted cellulosic fibrous material during continuous solvent pulping38US 5,865,948 AAlcell Technologies Inc. · 1999