Skip to content
PCE
Search Classifications
Search for IPC and CPC classification codes or keywords
IPC Subgroup
D21D 5/02

Straining or screening the pulp

Introduced: September 1968

Last revised: January 2006

Full Title

Purification of the pulp suspension by mechanical means; Apparatus therefor > Straining or screening the pulp

Classification Context

Section:
TEXTILES; PAPER
Class:
PAPER-MAKING; PRODUCTION OF CELLULOSE
Subclass:
TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE

Related Keywords

SCREEN(S) for pulp and paper stockSTRAINING of pulp and paper stock

3 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

Top Applicants

Top 10 applicants by patent filingsfor 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