Calenders (if restricted to the treatment of particular materials see the relevant class, e.g. B29C43/24, D06); Smoothing apparatus

Filing statistics

CPC D21G 1/00 belongs to the parent subclass D21G, which recorded 3,891 patent applications worldwide between 2013 and 2023. Annual filings grew from 292 in 2013 to 299 in 2023 (+2%), peaking at 419 applications in 2016. 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