D21H 23/02

Processes or apparatus for adding material to the pulp or to the

Official title: characterised by the manner in which substances are added

D21H23/02 (Processes or apparatus for adding material to the pulp or to the) appears on 1,668 US grants and 1,377 published applications in this corpus.

Search patents in D21H

Granted patents: 1,668
Published applications: 1,377
Assignees: 743
Inventors: 3,403
Latest grant: 6 Oct 2026

Filings by year

D21H 23/02: granted patents and published applications per publication year
Year	Granted patents	Published applications
1976	20	0
1977	14	0
1978	9	0
1979	3	0
1980	10	0
1981	15	0
1982	23	0
1983	19	0
1984	11	0
1985	23	0
1986	11	0
1987	11	0
1988	29	0
1989	36	0
1990	37	0
1991	26	0
1992	32	0
1993	30	0
1994	25	0
1995	28	0
1996	36	0
1997	50	0
1998	62	0
1999	66	0
2000	68	0
2001	50	12
2002	56	41
2003	51	67
2004	47	91
2005	24	82
2006	27	54
2007	42	56
2008	30	64
2009	19	48
2010	30	48
2011	37	41
2012	29	32
2013	38	52
2014	31	54
2015	34	49
2016	33	63
2017	51	49
2018	40	49
2019	35	53
2020	39	69
2021	38	56
2022	59	52
2023	35	57
2024	27	76
2025	44	36
2026	28	26

By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.

Processes or apparatus for adding material to the pulp or to the

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