D21B FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
Introduced: September 1968
Description
D21B covers the preparation and mechanical processing of fibrous raw materials destined for papermaking, including pulping processes, fiber separation, and treatment operations prior to paper formation. This subclass encompasses both wood and non-wood fiber sources (such as plant stalks, recycled paper, and textile waste) and their conversion into usable pulp through chemical, mechanical, or combination methods. The classification includes fiber washing, screening, cleaning, and other mechanical treatments that condition raw fibers for subsequent papermaking stages. D21B excludes the actual papermaking process itself (covered by D21D-D21H) and fiber-to-pulp chemical conversion that is part of integrated pulping systems.
Additional Content IPC
Splitting wood; manufacture of veneer, wooden sticks, wood shavings, wood fibres or wood powder Obtaining fibres from plant material (mechanical separation) Hackling or heckling machines Pretreatment of the finely-divided materials before digesting Methods of beating or refining pulp Purification of the pulp suspension by mechanical means
IPC and CPC are identically structured here. All 1 subcodes exist in both systems.
1 shared codes have differing titles between IPC and CPC.
Child Classifications
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- D21B 1/00 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) IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class D21,2013–2023, worldwide · Source: EPO PATSTAT
- VOITH PATENT DE 1,809
- STORA ENSO FI 1,467
- KEMIRA FI 1,086
- KIMBERLY-CLARK CORPORATION US 935
- VALMET TECHNOLOGIES FI 924
- VALMET SE 904
- P&G (PROCTER & GAMBLE COMPANY) US 862
- OJI HOLDINGS CORPORATION 696
- OMYA INTERNATIONAL CH 584
- SOUTH CHINA UNIVERSITY OF TECHNOLOGY 571
Top Applicants (CPC)
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