FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE (manufacture of articles by dry processes B27N)

Description

D21J covers the production of fibreboard and manufactured articles formed from cellulosic fibrous suspensions, including papier-mâché. This classification encompasses manufacturing processes such as wet-laying, pressing, drying, and bonding of cellulose fibers to create composite board materials or molded products. It includes technologies for controlling fiber distribution, density, and mechanical properties of the resulting boards and articles. Related processes in paper-making chemistry and pulp preparation are classified elsewhere in D21, while finished paper products themselves fall under different classifications.

Filing statistics

CPC subclass D21J recorded 4,550 patent applications worldwide between 2013 and 2023. Annual filings grew from 142 in 2013 to 588 in 2023 (+314%), peaking at 708 applications in 2021. The most active applicants in class D21 are VOITH PATENT (1,857 applications), STORA ENSO (1,552 applications) and KEMIRA (1,173 applications).

Source: EPO PATSTAT, worldwide filings