IPC Subgroup
D21D 1/02 Methods of beating; Beaters of the Hollander type
Introduced: September 1968
Last revised: January 2006
Full Title
Methods of beating or refining; Beaters of the Hollander type > Methods of beating; Beaters of the Hollander type
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
HOLLANDERS
8 direct subcodes
Child Classifications
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- D21D 1/04 Beater rolls or bars
- D21D 1/06 Bed plates
- D21D 1/08 Beaters with means for driving the pulp quickly
- D21D 1/1 Beaters with means for regulating the pressure between the beater roll and the bed plate
- D21D 1/12 Beaters with means for continuous pulp discharge
- D21D 1/14 Beaters with one beater roll and with vertical stuff circulation canal
- D21D 1/16 Beaters with means for returning the pulp over the head of the beater roll
- D21D 1/18 Beaters with two or more beater rolls
Top Applicants
Top 10 applicants by patent filingsfor 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