PlainPatent

CPC technology class · D21

D21J - Fibreboard

Fibreboard; manufacture of articles from cellulosic fibrous suspensions or from papier-mache. 270 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

270
US patents granted
D21
Parent CPC class
20
Active assignees
+168%
5-yr velocity

The verdict

Fibreboard ranks #588 of 670 CPC technology areas - 270 US patents granted since 2015, with filing up 168% over five years.

#588
of 670 CPC technology areas
270
US patents granted, 2015–2025
Footprint Internation…
leading assignee (20)
+168%
filing velocity, last 5 yrs
Top assignee: Footprint International, Llc (20 patents)

CPC subclass D21J - FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE - covers 270 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class D21 (PAPER-MAKING; PRODUCTION OF CELLULOSE). See our CPC classification guide for how the system works.

The competitive landscape in D21J is shaped by 20 distinct companies actively filing in this space. Footprint International, Llc leads with 20 patents, followed by Smart Planet Technologies, Inc. at 11 grants and Papacks Sales Gmbh at 8.

Filing activity in D21J is up 168% over the past five years versus 2015-2019, a sharp acceleration suggesting an emerging or fast-moving technology area. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is D21J innovation accelerating?

US utility-patent grants per year in D21J, 2015–2025 - recent five years are up 168% versus 2015–2019.

0102030405060 20152016201720182019202020212022202320242025 48

Who leads D21J?

The 12 most active assignees in FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE - wider bars mean more grants

patents

What this shows Footprint Internation… is the most active filer in D21J, holding 20 of the 270 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
View data table
Top patent holders in CPC subclass D21J
Rank Company Patents in D21J
#1 Footprint International, Llc 20
#2 Smart Planet Technologies, Inc. 11
#3 Papacks Sales Gmbh 8
#4 Celwise AB 8
#5 Golden Arrow Printing Technology (kunshan) Co., Ltd. 7
#6 Golden Arrow Painting Co., Ltd. 6
#7 Acorn WEST Llc 5
#8 Henry Molded Products, Inc. 5
#9 Westrock MWV, Llc 4
#10 Pulpac AB 4
#11 SIG Technology Ag 3
#12 USG Interiors, Llc 3
#13 Cascades Canada ULC 3
#14 Congruens Group, Llc 3
#15 Organoclick AB 3
#16 Huhtamaki Molded Fiber Technology B.v. 3
#17 Yulan Green Technology Co., Ltd. 3
#18 Borregaard AS 2
#19 Eco.logic Brands Inc. 2
#20 Fibria Innovations Inc. 2

About This Class

CPC subclass D21J belongs to class D21.

270 patents were granted in this class between 2015 and 2025.

20 companies actively patent in this space.

Classification System

Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.

← All Technology Classes Technology Rankings →

Footprint here vs. claim strategy

Each dot is a leading D21J assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 D21J assignees by class footprint. Bubble size = patents in D21J. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 D21J assignees by class footprint. Bubble size = patents in D21J. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 51015202530 0510152025 Patents in D21J Avg claims / patent (company-wide) Footprint Internation…Smart PlanetPapacks SalesCelwise AbGolden Arrow Printing…Golden Arrow PaintingAcorn WestHenry Molded ProductsWestrock MwvPulpac AbSig TechnologyUsg InteriorsCascades Canada UlcCongruens Group
Top 14 D21J assignees by class footprint. Bubble size = patents in D21J. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class D21J?
CPC subclass D21J covers FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE. It belongs to CPC class D21 (PAPER-MAKING; PRODUCTION OF CELLULOSE), with 270 US utility patents granted since 2015.
How many patents have been filed in D21J?
270 US utility patents were granted in CPC subclass D21J between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in D21J?
Footprint International, Llc leads D21J with 20 patents, making it the most active assignee in this technology area.
How is patent data for D21J collected?
Patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office. It covers all US granted utility patents and assigns CPC codes based on the technology described in each patent.
What is the difference between CPC class and subclass?
A CPC class (e.g., D21) is a broad technology category. Subclasses like D21J provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from USPTO PatentsView - official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent Editorial

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.