CPC Subgroup
D21B 1/06 by dry methods
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) > by dividing raw materials into small particles, e.g. fibres (breaking-up or cutting wood or the like by dry methods B27L; mechanical separation of fibres from plant material D01B1/00; hackling or heckling machines D01B5/00) > by dry methods
4 direct subcodes
Child Classifications
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- D21B 1/08 the raw material being waste paper (chemical part D21C5/02); the raw material being rags
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