D21C 9/08
Removal of fats, resins, pitch or waxes
Official title: Removal of fats, resins, pitch or waxes; {Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching (fats, waxes C11B; natural resins C09F1/00; hemicellulose C08B37/14; purification by mechanical means D21D5/00)}
D21C9/08 (Removal of fats, resins, pitch or waxes) appears on 196 US grants and 171 published applications in this corpus.
Search patents in D21C- Granted patents
- 196
- Published applications
- 171
- Assignees
- 144
- Inventors
- 464
- Latest grant
- 28 Apr 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 3 | 0 |
| 1988 | 1 | 0 |
| 1989 | 3 | 0 |
| 1990 | 2 | 0 |
| 1991 | 4 | 0 |
| 1992 | 1 | 0 |
| 1993 | 4 | 0 |
| 1994 | 6 | 0 |
| 1995 | 8 | 0 |
| 1996 | 8 | 0 |
| 1997 | 9 | 0 |
| 1998 | 12 | 0 |
| 1999 | 9 | 0 |
| 2000 | 5 | 0 |
| 2001 | 5 | 3 |
| 2002 | 4 | 6 |
| 2003 | 4 | 6 |
| 2004 | 0 | 3 |
| 2005 | 1 | 1 |
| 2006 | 3 | 4 |
| 2007 | 2 | 4 |
| 2008 | 0 | 11 |
| 2009 | 0 | 6 |
| 2010 | 3 | 9 |
| 2011 | 8 | 4 |
| 2012 | 3 | 9 |
| 2013 | 5 | 10 |
| 2014 | 11 | 6 |
| 2015 | 7 | 11 |
| 2016 | 3 | 13 |
| 2017 | 5 | 10 |
| 2018 | 5 | 10 |
| 2019 | 10 | 6 |
| 2020 | 11 | 8 |
| 2021 | 3 | 5 |
| 2022 | 9 | 7 |
| 2023 | 2 | 9 |
| 2024 | 4 | 6 |
| 2025 | 3 | 3 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Method for reducing amount of bacterial endospores in an aqueous fibre suspension28 Apr 2026US 12,612,736 B2Kemira Oyj
- Method to treat a condensate in a pulping process13 Jan 2026US 12,522,979 B2Nikede Comercio E RepresentaçõEs Ltda.
- Pulp quality monitoring28 Oct 2025US 12,454,796 B2Kemira Oyj
- Preparation of cellulose fibers21 Oct 2025US 12,448,730 B2Jena Trading Aps
- Method for suppressing sedimentation of suspended substance, method for suppressing pitch trouble, and method for detecting sedimentation of suspended substance11 Mar 2025US 12,247,354 B2Kurita Water Industries Ltd.
- Biocidal compositions16 Apr 2026US 2026/0103840 A1Italmatch Chemicals Gb Limited
- Method for Producing Lignocellulose Nanofibrils From Phosphorylated Fibers28 Aug 2025US 2025/0270761 A1
- Estimation device, estimation system, estimation program, and estimation method17 Jul 2025US 2025/0231168 A1Kurita Water Industries Ltd.
- Processes and systems for producing nanocellulose from old corrugated containers6 Feb 2025US 2025/0043508 A1GranBio Intellectual Property Holdings, LLC
- Scale inhibition for pulp digesters25 Jul 2024US 2024/0247439 A1Ecolab USA Inc.
Most cited
By later US patents
- Process and apparatus for the deresination and brightness improvement of cellulose pulp59US 4,444,621 AMo och Domsjo Aktiebolag · 1984
- Method for obtaining a purified cellulose product from corn hulls43US 4,239,906 AStandard Brands Incorporated · 1980
- Control of pulp-paper mill pitch deposits33US 3,992,249 AAmerican Cyanamid Company · 1976
- Method for removing stickies from secondary fibers using supercritical CO.sub.2 solvent extraction27US 5,009,746 AKimberly-Clark Corporation · 1991
- Pitch control27US 5,300,194 AW. R. Grace & Co.-Conn. · 1994