FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT

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.

Filing statistics

IPC subclass D21B recorded 9,638 patent applications worldwide between 2013 and 2023. Annual filings grew from 457 in 2013 to 877 in 2023 (+92%), peaking at 1,210 applications in 2020. The most active applicants in class D21 are VOITH PATENT (1,809 applications), STORA ENSO (1,467 applications) and KEMIRA (1,086 applications).

Source: EPO PATSTAT, worldwide filings

Additional Content

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