Depth Filtration Filter Sizing Patents: Who Leads, Where the Gaps Are 2026
- 54.5% of all 112 records sit with just five assignees, and 81.3% sit with ten — this field is concentrated at the top with a long tail of single-filing entrants below tenth place.
- Filings fell 86% from 7 in 2021 to 1 in 2024, the last year the data can treat as complete before publication lag thins out 2025-2026.
- B01D separation claims cover 84.8% of records, but bioprocess-adjacent classes like C12M bioreactors (17.9%) and C12P fermentation (15.2%) sit on far thinner claim density.
Filing growth compares 2021 (7 records) with 2024 (1) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 112 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Depth filtration filter sizing sits at the intersection of separation engineering and bioprocessing: how a filter’s area, capacity and pressure limits are modelled and scaled as a process moves from bench to commercial volume. The 112 records in scope span filter media construction, capacity and sizing models, and scale-transition methods used to size depth filters for biological fluid processing, drawing on IPC classes for separation processes (B01D), filtration media (B01D39), and cell and microorganism handling (C12N).
The earliest activity traces back through the 2015-2026 window with a clear peak in 2023, after which filing counts thin — partly a real slowdown, partly the roughly 18-month lag between filing and publication that always understates the most recent one to two years.
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Filing trend and technology composition
The trend line and the IPC breakdown below are drawn from the same 112-record set and use the denominators given in the underlying data — record counts for the trend, and share of all records for each IPC class.
Filing activity: a 2023 peak, then a lag-affected tail
Filings climbed to a peak of 10 in 2023 before falling to 1 in 2024, a -86% move from the 7 filed in 2021. Do not read 2025 and 2026 as continuing that decline: at this dataset's cut-off, publication has not caught up with filing for those years.
IPC composition: filtration dominates, bioprocess classes trail
B01D separation-process claims appear on 84.8% of the 112 records, making it the dominant class by a wide margin. C07K peptide/protein claims (28.6%) and C12N microorganism claims (19.6%) show meaningful but much thinner coverage, and C12M bioreactor claims (17.9%) and C12P fermentation claims (15.2%) sit thinner still — each record can carry more than one class, so these figures do not sum to 100%.
Shares are the percentage of the 112 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Depth Filtration Filter Sizing with Eureka
This page is one run against one query. Ask Eureka your own question about depth filtration filter sizing and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this space
US7645312B2 — Pleated multi-layer filter media and cartridge
A pleated filter element includes a composite depth filter medium formed into a plurality of pleats. The composite depth filter medium includes a plurality of depth filter media layers, each including adsorber particulate matter, each layer optionally under about 1300 microns thick, with at least 50% by weight of adsorber particulate matter across the layer set.Filed by 3M Innovative Properties Company; granted 2010-01-12.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5217627A | System and method for processing biological fluid | 217 |
| 2 | US5616254A | System and method for processing biological fluid | 103 |
| 3 | US20130037481A1 | Nonwoven nanofiber WEBS containing chemically active particulates and methods of making and using same | 99 |
| 4 | US6309605B1 | Well(s) containing filtration devices | 73 |
| 5 | US5360545A | Filter for obtaining platelets | 47 |
| 6 | EP2561128B1 | Nonwoven fibrous WEBS containing chemically active particulates and methods of making and using same | 46 |
| 7 | US7645312B2 | Pleated multi-layer filter media and cartridge | 42 |
| 8 | WO2011133396A1 | Nonwoven fibrous WEBS containing chemically active particulates and methods of making and using same | 34 |
| 9 | WO2011133394A1 | Nonwoven nanofiber WEBS containing chemically active particulates and methods of making and using same | 31 |
| 10 | WO2001091880A1 | Improvements in blood filters, blood collection and processing systems, and methods therefor | 30 |
Citation counts favour older filings simply because they have had longer to accumulate citations inside this corpus — treat them as a measure of influence on later filers, not as evidence that the claims are still the strongest available today.
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
Three patterns matter more than any single ranking: how tight the leadership group is, how the technology splits across adjacent fields, and where the real citation weight sits.
Ten assignees hold four in five records
With 54.5% of all 112 records held by five assignees and 81.3% held by ten, new entrants are filing into a field where the core sizing and media-construction claims are already staked out by a small group. The leader alone accounts for 19 records against a fifth-place count of 10 and a tenth-place count of 4 — the drop-off after the top few is steep.
Activity cooled sharply through the early 2020s
Filing counts fell from 7 in 2021 to 1 in 2024, a decline the dataset can state with confidence because 2024 is the most recent year unaffected by publication lag. Whether that decline continues into 2025-2026 cannot yet be read from this data.
Filtration claims dwarf fermentation-adjacent claims
B01D separation-process claims cover 84.8% of the 112 records, while C12P fermentation claims cover only 15.2% and C12M bioreactor claims 17.9%. That gap suggests the sizing and media mechanics are heavily claimed, while the interface between depth filtration and upstream bioprocess steps is comparatively open.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to depth filtration filter sizing, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Asahi Kasei Medical Co Ltd | Baxter International Inc | 5 |
| Asahi Kasei Medical Co Ltd | Fenwal Inc | 3 |
| BASF Corporation | LISA RUDOLPH ERNEST | 2 |
| BASF Corporation | ABRAHAM GEORGE | 2 |
| 3M Innovative Properties Company | WU TIEN T | 2 |
| 3M Innovative Properties Company | VINCENT BERNARD | 2 |
| 3M Innovative Properties Company | LALOUCH LAHOUSSAINE | 2 |
| 3M Innovative Properties Company | VALL DAVID L | 1 |
Only 10 co-assignee pairs appear across the dataset, and the strongest pair co-files just 5 times — most assignees in this space file solo rather than through joint development arrangements.
Who holds the claim space, and where it is thinning
The ranked leaders account for most of the volume, but recent-year momentum data shows several of them recording zero filings in the latest year — a sign that even established holders are not actively adding to their positions right now.
A single assignee holds the largest share
The leading assignee's 19 records outpace the fifth-place count of 10 by nearly double, giving it the clearest single position in the ranking, though its recent-year momentum shows no new filings in the latest year on record.
A tight band separates the mid-tier from the tail
Fifth place holds 10 records and tenth place holds 4, meaning the top 10 combined still take 81.3% of all 112 records — the mid-tier is thin but not negligible, and it is where a challenger with a differentiated sizing model could realistically compete.
Most of the ranking is single-digit filers
Beyond the top 10, the ranking runs to 57 companies total, most holding only a handful of records each. That long tail signals a field where the core mechanics are contested by a few firms but plenty of adjacent applications remain unclaimed by any dominant player.
| Assignee | Recent year | YoY |
|---|---|---|
| BASF Corporation | 0 | — |
| Alcan International Ltd | 0 | — |
| Regeneron Pharmaceuticals Inc | 0 | -100% |
| EMD Millipore Corp | 0 | -100% |
| 3M Innovative Properties Company | 0 | — |
| Asahi Kasei Medical Co Ltd | 0 | — |
| Baxter International Inc | 0 | — |
| SARTORIUS GMBH | 0 | — |
Where to take this analysis
The dataset points to a field with a settled core and a thinning edge. The next step depends on whether you are defending a position or looking for one to file into.
Check freedom to operate against the leader's claims
With one assignee holding 19 of 112 records, any new filing on core filter-media or sizing-model claims should be checked against that portfolio first, not just the aggregate ranking.
Run a claim comparison in Eureka →Map the bioreactor-fermentation interface for white space
C12M and C12P classes cover under 18% of records each against B01D's 84.8%, suggesting the upstream process interface is comparatively open for a differentiated sizing claim.
Explore white space in Eureka →Common questions about this landscape
The dataset ranks 57 companies, but activity is heavily concentrated: the top 5 assignees hold 54.5% of all 112 records in scope, and the top 10 hold 81.3%. The leading assignee alone accounts for 19 records, well ahead of the fifth-place holder at 10. Beyond the top 10, most of the remaining 47 ranked companies hold only a handful of records each, forming a long tail rather than a second tier of comparable size.
Filings dropped from 7 in 2021 to 1 in 2024, a decline of 86% over that span, with a peak of 10 records in 2023 in between. That 2024 figure is the most recent year the dataset can treat as complete, because publication typically lags filing by around 18 months. The apparent thinning in 2025 and 2026 should not be read as a continuing decline — it is largely an artefact of that lag, not confirmed shrinking activity.
B01D, covering separation processes including filtration, appears on 84.8% of the 112 records and is by far the dominant class. Bioprocess-related classes appear at lower but still notable rates: C07K (peptides and proteins) at 28.6%, C12N (microorganisms and genetic engineering) at 19.6%, C12M (bioreactors) at 17.9%, and C12P (fermentation) at 15.2%. Because a single record can carry several IPC classes, these percentages add up to more than 100% and should not be summed.
US7645312B2, assigned to 3M Innovative Properties Company and granted in 2010, claims a pleated composite depth filter medium built from multiple filter-media layers, each containing adsorber particulate matter and optionally under about 1300 microns thick, with at least 50% adsorber particulate by weight. It is one of the representative filings in this dataset for filter-media construction rather than sizing-model methodology specifically. Anyone designing pleated multi-layer adsorptive depth filter media should review its claim scope directly rather than relying on this summary, since exact claim boundaries determine freedom to operate.
The clearest signal comes from the gap between the dominant B01D separation-process class at 84.8% of records and thinner bioprocess-adjacent classes such as C12M bioreactors (17.9%) and C12P fermentation (15.2%). That gap suggests the core filter-media and separation mechanics are heavily claimed while the interface between depth filtration and upstream bioprocess steps, such as bioreactor-integrated sizing or fermentation-stage capacity prediction, is comparatively open. Co-filing is also rare in this field, with only 10 co-assignee pairs recorded, suggesting few joint development programmes are actively claiming these adjacent areas together.
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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.