DIFF Main Group
D21G 1/00 Calenders (if restricted to the treatment of particular materials see the relevant class, e.g. B29C43/24, D06); Smoothing apparatus
Introduced: September 1968
Title
Titles differ between systems:
IPC: Calenders; Smoothing apparatus
CPC: Calenders (if restricted to the treatment of particular materials see the relevant class, e.g. B29C43/24, D06); Smoothing apparatus
Full Title
Full titles differ between systems:
IPC:
Calenders; Smoothing apparatus
CPC:
Calenders (if restricted to the treatment of particular materials see the relevant class, e.g. B29C43/24, D06); Smoothing apparatus
CPC subdivides this area 6x more granularly than IPC with 5 additional codes.
5 codes are CPC-only extensions.
1 shared codes have differing titles between IPC and CPC.
Child Classifications
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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