D21C 3/266
The same pulping agent being used in all stages
Official title: {the same pulping agent being used in all stages (D21C3/263 takes precedence)}
D21C3/266 (The same pulping agent being used in all stages) appears on 15 US grants and 5 published applications in this corpus.
Search patents in D21C- Granted patents
- 15
- Published applications
- 5
- Assignees
- 14
- Inventors
- 29
- Latest grant
- 4 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 1 | 0 |
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 2 | 1 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 1 | 1 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 2 |
| 2025 | 0 | 1 |
| 2026 | 2 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Optimization of chemical consumption in biomass delignification4 Aug 2026US 12,698,589 B2Sixring Inc.
- Optimization of chemical consumption in biomass delignification17 Feb 2026US 12,553,180 B2Sixring Inc.
- System and method for reclaiming rejects in sulfite pulping4 Nov 2014US 8,877,007 B2University of New Brunswick
- Apparatus for pulping sawdust30 Apr 2002US 6,379,504 B1Andritz Inc.
- Batch cooking with black liquor pretreatment26 Feb 2002US 6,350,348 B1Andritz-Ahlstrom Inc.
- Optimization of chemical consumption in biomass delignification13 Feb 2025US 2025/0052002 A1Sixring Inc.
- Method for producing products based on non-woody biomass as raw material30 May 2024US 2024/0175206 A1Technische UniversitäT Wien
- Optimization Of Chemical Consumption in Biomass Delignification15 Feb 2024US 2024/0052566 A1Sixring Inc.
- System and Method for Reclaiming Rejects in Sulfite Pulping27 Feb 2014US 2014/0053993 A1University of New Brunswick
- Method and apparatus for pulping sawdust7 Mar 2002US 2002/0026990 A1Andritz-Ahlstrom Inc.
Most cited
By later US patents
- Two-stage chemical treatment of mechanical wood pulp with sodium sulfite17US 4,502,918 AMacMillan Bloedel Limited · 1985
- Cooking cellulose material with high alkali concentrations and/or high pH12US 5,635,026 AAhlstrom Machinery Inc. · 1997
- Cooking cellulose material using high alkali concentrations and/or high pH near the end of the cook12US 5,779,856 AAhlstrom Machinery Inc. · 1998
- Apparatus for pulping sawdust10US 6,379,504 B1Andritz Inc. · 2002
- Batch digester multi-stage pulping process9US 4,849,052 ABeloit Corporation · 1989