D21F 1/00
Wet end of machines for making continuous webs of paper
D21F1/00 (Wet end of machines for making continuous webs of paper) appears on 2,969 US grants and 1,666 published applications in this corpus.
Search patents in D21F- Granted patents
- 2,969
- Published applications
- 1,666
- Assignees
- 659
- Inventors
- 3,271
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 34 | 0 |
| 1977 | 32 | 0 |
| 1978 | 45 | 0 |
| 1979 | 34 | 0 |
| 1980 | 41 | 0 |
| 1981 | 36 | 0 |
| 1982 | 41 | 0 |
| 1983 | 53 | 0 |
| 1984 | 50 | 0 |
| 1985 | 77 | 0 |
| 1986 | 40 | 0 |
| 1987 | 50 | 0 |
| 1988 | 63 | 0 |
| 1989 | 65 | 0 |
| 1990 | 67 | 0 |
| 1991 | 77 | 0 |
| 1992 | 70 | 0 |
| 1993 | 47 | 0 |
| 1994 | 56 | 0 |
| 1995 | 69 | 0 |
| 1996 | 78 | 0 |
| 1997 | 75 | 0 |
| 1998 | 118 | 0 |
| 1999 | 105 | 0 |
| 2000 | 97 | 0 |
| 2001 | 118 | 16 |
| 2002 | 83 | 89 |
| 2003 | 67 | 85 |
| 2004 | 72 | 120 |
| 2005 | 58 | 71 |
| 2006 | 67 | 100 |
| 2007 | 54 | 101 |
| 2008 | 52 | 87 |
| 2009 | 67 | 67 |
| 2010 | 62 | 78 |
| 2011 | 74 | 58 |
| 2012 | 65 | 58 |
| 2013 | 42 | 56 |
| 2014 | 58 | 54 |
| 2015 | 33 | 45 |
| 2016 | 42 | 61 |
| 2017 | 40 | 48 |
| 2018 | 43 | 47 |
| 2019 | 37 | 71 |
| 2020 | 51 | 58 |
| 2021 | 39 | 62 |
| 2022 | 59 | 46 |
| 2023 | 52 | 64 |
| 2024 | 50 | 58 |
| 2025 | 39 | 36 |
| 2026 | 25 | 30 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- D21F 1/0027Screen-cloths1,235
- D21F 1/66Pulp catching, de-watering, or recovering444
- D21F 1/02Head boxes of fourdrinier machines427
- D21F 1/48Suction apparatus369
- D21F 1/32Washing wire-cloths or felts143
- D21F 1/36Guiding mechanisms121
- D21F 1/08Regulating consistency100
- D21F 1/06Regulating pulp flow99
All 24 subgroupsShow fewer
- D21F 1/30Protecting wire-cloths from mechanical damage67
- D21F 1/44Watermarking devices58
- D21F 1/009Fibre-rearranging devices50
- D21F 1/10Wire-cloths50
- D21F 1/18Shaking apparatus for wire-cloths and associated parts38
- D21F 1/34Construction or arrangement of spraying pipes35
- D21F 1/56Deckle frame arrangements32
- D21F 1/0018Devices for dispensing fibres in a fluid30
- D21F 1/04Head boxes of cylinder machines23
- D21F 1/60Cylinder moulds21
- D21F 1/0009Regulating the freeness of the pulp16
- D21F 1/24Tilting, raising, or lowering mechanisms for wire-cloths12
- D21F 1/58Deckle straps5
- D21F 1/62Sand traps2
- D21F 1/54Skimming devices0
- D21F 1/64Magnetic separators0
Recent patents
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- Method and device for producing a fibrous web17 Sep 2026US 2026/0275634 A1Andritz Kuesters GmbH
- Dewatering apparatus and process17 Sep 2026US 2026/0275635 A1The Procter & Gamble Company
- Ceiling basemat water reduction through strategic use of pressing and vacuuming17 Sep 2026US 2026/0275636 A1USG Interiors, Inc.
- Apparatus for forming a substrate10 Sep 2026US 2026/0265971 A1Kimberly-Clark Worldwide, Inc.
- Water laminated tissue products20 Aug 2026US 2026/0243031 A1Kimberly-Clark Worldwide, Inc.
Most cited
By later US patents
- Deflection member476US 4,528,239 AThe Procter & Gamble Company · 1985
- Method of making soft tissue products425US 5,672,248 AKimberly-Clark Worldwide, Inc. · 1997
- Method of making a foraminous member399US 4,514,345 AThe Procter & Gamble Company · 1985
- Papermaking belt and method of making the same using differential light transmission techniques387US 5,334,289 AThe Procter & Gamble Company · 1994
- Apparatus for making soft tissue products355US 5,429,686 ALindsay Wire, Inc. · 1995