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DIFF Subgroup
D21H 25/04

Physical treatment, e.g. heating, irradiating (D21H25/18 takes precedence; dryer section of machines for making continuous webs of paper D21F5/00)

Introduced: January 1990

Title

Titles differ between systems:

IPC: Physical treatment, e.g. heating or irradiating

CPC: Physical treatment, e.g. heating, irradiating (D21H25/18 takes precedence; dryer section of machines for making continuous webs of paper D21F5/00)

Full Title

Full titles differ between systems:

IPC:

After-treatment of paper not provided for in groups > Physical treatment, e.g. heating or irradiating

CPC:

After-treatment of paper not provided for in groups D21H17/00 - D21H23/00 > Physical treatment, e.g. heating, irradiating (D21H25/18 takes precedence; dryer section of machines for making continuous webs of paper D21F5/00)

IPC and CPC are identically structured here. All 1 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 25/06 of impregnated or coated paper (D21H25/08 takes precedence) since 1990 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