CPC Subgroup
D21B 1/026 Full Title
Fibrous raw materials or their mechanical treatment (pretreatment of the finely-divided materials before digesting D21C1/00; methods of beating or refining pulp D21D1/00; purification of the pulp suspension by mechanical means D21D5/00) > Pretreatment of the raw materials by chemical or physical means (removal of bark B27L)
1 direct subcode
Child Classifications
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Top Applicants
Top 10 applicants by patent filingsfor 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