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PCE
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DIFF Main Group
D21C 7/00

Digesters

Introduced: September 1968

IPC and CPC are identically structured here. All 8 subcodes exist in both systems.

Child Classifications

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  • D21C 7/02 Rotary digesters IPC+CPC Available in IPC and CPC
  • D21C 7/04 Linings IPC+CPC Available in IPC and CPC
  • D21C 7/06 Feeding devices IPC+CPC Available in IPC and CPC
  • D21C 7/08 Discharge devices IPC+CPC Available in IPC and CPC
  • D21C 7/10 Heating devices IPC+CPC Available in IPC and CPC
  • D21C 7/12 Devices for regulating or controlling IPC+CPC Available in IPC and CPC
  • D21C 7/14 Means for circulating the lye IPC+CPC Available in IPC and CPC
  • D21C 7/16 Safety devices IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class D21,2013–2023, worldwide · Source: EPO PATSTAT

  1. VOITH PATENT DE 1,809
  2. STORA ENSO FI 1,467
  3. KEMIRA FI 1,086
  4. KIMBERLY-CLARK CORPORATION US 935
  5. VALMET TECHNOLOGIES FI 924
  6. VALMET SE 904
  7. P&G (PROCTER & GAMBLE COMPANY) US 862
  8. OJI HOLDINGS CORPORATION 696
  9. OMYA INTERNATIONAL CH 584
  10. SOUTH CHINA UNIVERSITY OF TECHNOLOGY 571

Top Applicants (CPC)

Class D21,2013–2023, worldwide · Source: EPO PATSTAT

  1. VOITH PATENT DE 1,857
  2. STORA ENSO FI 1,552
  3. KEMIRA FI 1,173
  4. KIMBERLY-CLARK CORPORATION US 1,107
  5. VALMET TECHNOLOGIES FI 965
  6. VALMET SE 943
  7. P&G (PROCTER & GAMBLE COMPANY) US 941
  8. OMYA INTERNATIONAL CH 821
  9. UPM-KYMMENE CORPORATION FI 512
  10. SEIKO EPSON CORPORATION JP 501