D21H 23/00 Processes or apparatus for adding material to the pulp or to the paper (applying liquids or other fluent material to surfaces, in general B05; processes for making continuous lengths of paper D21F11/00)
Introduced: January 1990
Title
Titles differ between systems:
IPC: Processes or apparatus for adding material to the pulp or to the paper
CPC: Processes or apparatus for adding material to the pulp or to the paper (applying liquids or other fluent material to surfaces, in general B05; processes for making continuous lengths of paper D21F11/00)
Full Title
Full titles differ between systems:
Processes or apparatus for adding material to the pulp or to the paper
Processes or apparatus for adding material to the pulp or to the paper (applying liquids or other fluent material to surfaces, in general B05; processes for making continuous lengths of paper D21F11/00)
IPC and CPC are identically structured here. All 3 subcodes exist in both systems.
1 shared codes have differing titles between IPC and CPC.
IPC defines codes here since 1990.
Child Classifications
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- D21H 23/02 characterised by the manner in which substances are added since 1990 IPC+CPC Available in IPC and CPC
- D21H 23/76 characterised by choice of auxiliary compounds which are added separately from at least one other compound, e.g. to improve the incorporation of the latter or to obtain an enhanced combined effect (D21H17/18, D21H17/70, D21H23/10 take precedence) since 1990 +1 CPC IPC+CPC Available in IPC and CPC
- D21H 23/78 Controlling or regulating not limited to any particular process or apparatus since 1990 IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class D21,2013–2023, worldwide · Source: EPO PATSTAT
- VOITH PATENT DE 1,809
- STORA ENSO FI 1,467
- KEMIRA FI 1,086
- KIMBERLY-CLARK CORPORATION US 935
- VALMET TECHNOLOGIES FI 924
- VALMET SE 904
- P&G (PROCTER & GAMBLE COMPANY) US 862
- OJI HOLDINGS CORPORATION 696
- OMYA INTERNATIONAL CH 584
- SOUTH CHINA UNIVERSITY OF TECHNOLOGY 571
Top Applicants (CPC)
Class D21,2013–2023, worldwide · Source: EPO PATSTAT
- VOITH PATENT DE 1,857
- STORA ENSO FI 1,552
- KEMIRA FI 1,173
- KIMBERLY-CLARK CORPORATION US 1,107
- VALMET TECHNOLOGIES FI 965
- VALMET SE 943
- P&G (PROCTER & GAMBLE COMPANY) US 941
- OMYA INTERNATIONAL CH 821
- UPM-KYMMENE CORPORATION FI 512
- SEIKO EPSON CORPORATION JP 501