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PCE
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DIFF Subgroup
D21H 23/10

at least two kinds of compounds being added

Introduced: January 1990

Full Title

Full titles differ between systems:

IPC:

Processes or apparatus for adding material to the pulp or to the paper > characterised by the manner in which substances are added > Addition to the pulp; After-treatment of added substances in the pulp > Controlling the addition > by measuring pulp properties, e.g. zeta potential or pH > at least two kinds of compounds being added

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) > characterised by the manner in which substances are added > Addition to the pulp; After-treatment of added substances in the pulp > Controlling the addition > by measuring pulp properties, e.g. zeta potential, pH > at least two kinds of compounds being added

No child classifications to compare. This is a leaf node in both 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