Nonwoven Filter Media Patents: Leaders, Trends & White Space 2026
A data-backed look at nonwoven filter media patents: assignee concentration, filing trends through 2026, IPC technology composition and where claim space remains open.
Filing growth = 2021 (6 records) → 2024 (2); 2024 is the last year we treat as complete. Top-5 share = the 5 largest assignees ÷ all 339 records in scope (CR5), not the ranked leaders only.
What the nonwoven filter media patent record shows
Nonwoven filter media sit at the intersection of fibre engineering and filtration performance: a formed web of fibres — spunbond, wet-laid, meltblown or otherwise — that is claimed for its ability to capture particulates, gases or liquids. The 339 records in scope for this dataset, drawn from filings classified under D01, D03 and D04 with explicit filtration and textile-material language, cover 2015 through the 2026 data cut-off. Two IPC subclasses, D04H (nonwovens & felts) and B01D (separation processes), appear together across the large majority of these filings, showing that most claims combine a web-forming step with an explicit filtration mechanism rather than treating either as a standalone invention.
Filing activity rose through the late 2010s, peaked in 2022, and has declined across the last complete-year window on record. Ownership is concentrated at the top of a 99-company ranking, but the concentration is partial rather than total, leaving room below the leaders for filings in less-claimed branches such as pulp-and-paper-based media or chemically treated fibre routes.
Filing trends and technology composition
The 339 records in scope span 2015 through the 2026 cut-off, with publication lag meaning the most recent two years are still filling in.
Filing activity peaked in 2022
Annual filings rose from 17 in 2017 to a peak of 30 in 2022. The hero figure of -67% covers only the complete-year window from 2021 (6) to 2024 (2); years after 2024 are too new to read as a trend because publication typically lags filing by around 18 months.
Publication lags filing by roughly 18 months, so 2025 onwards are still filling in. Growth rates on this page therefore end at 2024; running them to the last bar would understate the field.
D04H and B01D dominate the classification mix
D04H (nonwovens & felts) appears on 91.4% of the 339 records and B01D (separation processes) on 70.2%, confirming that most filings combine a nonwoven-forming claim with an explicit filtration claim. Smaller branches — D21H (8.0%) and A41D (7.1%) — carry far fewer records, marking the thinner, less-claimed edges of the field.
Shares are the percentage of the 339 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Nonwoven Filter Media Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about nonwoven filter media patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaThe records other filings are measured against
Low density nonwoven glass fiber web (US20040224594A1, Hollingsworth & Vose)
The present invention relates to wet laid nonwoven glass fiber webs, filter media formed of or containing wet laid nonwoven glass fibers webs, and methods of making the same using a wet laid processing technique. The filter media are particularly advantageous in that it has been discovered that adjusting the pH during wet laid processing will produce a glass fiber web having improved filtration properties. In particular, neutralizing the pH of a slurry containing mainly glass wool fibers unexpectedly yields a non-electret, filter media that has a gamma value of at least about 14, which is a significant improvement over non-electret, wet laid glass filter media currently on the market.Filed 2004-11-11. Claims a non-electret filtration performance route distinct from the electret-charging patents that dominate the citation table.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5496507A | Method of charging electret filter media | 927 |
| 2 | US6119691A | Electret filter media | 272 |
| 3 | US5597645A | Nonwoven filter media for gas | 227 |
| 4 | US6169045B1 | Nonwoven filter media | 193 |
| 5 | US20080311815A1 | Nonwovens produced from multicomponent fibers | 181 |
| 6 | US5744236A | Hollow fibers impregnated with solid particles | 110 |
| 7 | US6090731A | High density nonwoven filter media | 108 |
| 8 | US5855784A | High density nonwoven filter media | 89 |
| 9 | US20100159770A1 | Nonwoven web and filter media containing partially split multicomponent fibers | 84 |
| 10 | KR1020120002491A | Filter Media for Liquid Filter Using Nano-Fiber Web by Electrospinning, Method of Manufacturing the Same and … | 82 |
Ranked by citation count within the searched corpus; older electret-charging patents dominate the top of this list, which reflects influence accumulated over time rather than current filing activity.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Four figures from the dataset that change where a new filing or a design-around search should start.
The top of the field is crowded, the rest is open
With the top 5 assignees holding 39.2% of all 339 records and the top 10 holding 60.2%, the ranked leaders occupy the electret and structural nonwoven core. Below them, the field thins quickly across the remaining ranked companies.
Peak activity has passed, recent years are still filling in
Filings peaked at 30 in 2022 and fell from 6 in 2021 to 2 in 2024. That drop is real for the complete-year window, but 2025-2026 figures will rise as publication catches up with an 18-month typical lag.
Nonwoven forming is the near-universal base claim
D04H (nonwovens & felts) appears on 91.4% of the 339 records, and B01D (separation processes) on 70.2%. Most filings claim both together, which is why isolated D04H-only or B01D-only filings are comparatively rare.
Electret charging is the reference point other filings cite against
The most-cited record in the corpus concerns electret filter media charging, and the next two most-cited records are also electret-related. High citation counts here reflect age and influence on the field's vocabulary, not that the mechanism is still the most active filing target.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to nonwoven filter media patent landscape, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| E.I. du Pont de Nemours and Company | BHA Group Holdings, Inc. | 4 |
| Kimberly-Clark Worldwide, Inc. | ZIMMERMAN NANCY J | 2 |
| Kimberly-Clark Worldwide, Inc. | WALSER SUSAN KATHLEEN | 2 |
| Kimberly-Clark Worldwide, Inc. | SMITH REGINALD | 2 |
| Kimberly-Clark Worldwide, Inc. | REDDY KIRAN K | 2 |
| Kimberly-Clark Worldwide, Inc. | MYERS DAVID | 2 |
| Kimberly-Clark Worldwide, Inc. | FRAZIER NINA | 2 |
| Kimberly-Clark Worldwide, Inc. | CHAMBERS JR LEON EUGENE | 2 |
Only 10 co-assignee pairs appear across the dataset, and the strongest pairs link a small number of named individuals or affiliated entities to a single corporate assignee — most filings in nonwoven filter media are filed by a single assignee working alone.
Where to take this analysis next
The dataset points to specific follow-up questions for R&D, IP counsel and competitive-intelligence teams working in nonwoven filter media.
Check freedom to operate against the electret core
The most-cited records in this dataset concern electret filter media charging. Any new filing or product using charge-based mechanical filtration should be checked against this cluster before development proceeds.
Search the full claim set in EurekaExplore the thinner IPC branches
D21H and A41D carry far fewer records than the dominant D04H/B01D core, suggesting under-claimed combinations in paper-derived or garment-integrated filter media worth a closer look.
Explore white space in EurekaTrack assignee activity below the top 10
With 60.2% of records held by the top 10 assignees, the remaining 39.8% is spread across a long tail of smaller filers. Monitoring this tail can surface new entrants before they scale.
Set up assignee tracking in EurekaFrequently asked questions
The assignee ranking covers 99 companies counted by patent family, with the leader holding 43 records and the field concentrated toward the top: the top 5 combined hold 39.2% of all 339 records in scope, and the top 10 combined hold 60.2%. That leaves a long tail of single- or few-filing entrants below the leaders. Companies active in nonwovens, filtration media and specialty fibres — including large industrial and materials firms — make up most of the ranked leaders, but no single filer controls a majority of the field on its own.
Nonwovens and felts (IPC class D04H) appear on 91.4% of the 339 records in scope, and separation/filtration processes (B01D) appear on 70.2%, meaning most patents combine both elements rather than claiming one in isolation. Secondary areas include chemical fibre and filament features (D01F, 23.6%) and man-made filament spinning (D01D, 17.1%). Because a single record can carry multiple IPC classes, these shares add up to more than 100% and should not be summed.
Filings rose from 17 in 2017 to a peak of 30 in 2022, then declined across the complete-year window from 2021 (6) to 2024 (2), a drop of 67% over that three-year span. Years after 2024 are not reliable indicators of a slowdown because publication lags filing by roughly 18 months, so the most recent filing years are systematically undercounted in any dataset. A clearer read on 2025-2026 activity will only be possible once those records finish publishing.
US20040224594A1, assigned to Hollingsworth & Vose and filed in 2004, claims a wet-laid nonwoven glass fibre filter medium made by neutralizing slurry pH during processing to reach a specific non-electret filtration performance level (a gamma value of at least about 14). It blocks work that follows this exact wet-laid, pH-controlled, non-electret route at that performance band, but it does not cover electret-charged filter media or fibre routes that reach filtration performance through other mechanisms. Anyone evaluating freedom to operate near this claim should check its full prosecution history and family, not just the published abstract.
The thinnest branches in this dataset relative to the dominant nonwoven-and-filtration core are D21H, pulp and paper compositions, at 8.0% of the 339 records, and A41D, outerwear and garments, at 7.1%. Both sit adjacent to the well-claimed D04H/B01D core but show far less filing density, suggesting under-explored combinations such as paper-derived filter substrates or garment-integrated filter media. Receiving-office data also shows lighter filing volumes in Canada (30) and South Korea (19) compared with the US (79) and EPO (75), pointing to a secondary regional gap.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.