Feedstock Flexibility Cellulose Fibre Patents: Top Companies & Trends 2026
- Concentration is modest at the top. the leading assignee holds 44 records but the top 5 combined account for only 21.9% of the 553 records in scope — no single filer controls the field.
- Filing has cooled from its 2017 peak. activity dropped from 32 filings in 2017 to 16 in 2021 and 11 in 2024, a -31% change over that three-year span, though 2025-2026 counts are still filling in due to publication lag.
- Pulp processing dominates the claim space. D21C pulp production and treatment appears in 65.1% of the 553 records, far ahead of polysaccharide chemistry and fibre-feature classes.
Filing growth compares 2021 (16 records) with 2024 (11) — 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 553 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Feedstock flexibility covers the technical work of taking variable cellulosic inputs — virgin dissolving pulp, recycled cotton, post-consumer textile waste, agricultural residues — and producing fibre-grade material with consistent degree of polymerisation, hemicellulose content and ash tolerance. The 553 records in scope sit at the intersection of pulp chemistry and fibre manufacturing: pretreatment methods that strip contaminants and lignin, distribution-control steps that narrow molecular weight spread, and processes that make recycled or non-wood feedstocks behave predictably enough for viscose, lyocell or other regenerated-cellulose lines.
The dataset spans filings from 2015 through the 2026 cut-off, drawn from a search string targeting dissolving pulp, cellulosic raw material processability and recycled cotton pulp language, cross-referenced against pretreatment, contaminant carryover and fibre property variation claim terms.
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Filing trend and technology composition
The two views below come from the same 553-record set: one tracks filing activity by year, the other breaks the same records down by IPC subclass so multi-class filings show up in more than one bucket.
Filing activity, 2017-2026
Filings peaked at 32 in 2017 and have since eased; the 2021-to-2024 span shows a -31% change (16 to 11 filings). Because publication trails filing by roughly 18 months, the low counts shown for 2025 and 2026 understate real filing activity rather than signalling a slowdown.
IPC subclass distribution
D21C (pulp production and treatment) touches 65.1% of the 553 records, making it the dominant claim territory. C08B polysaccharide chemistry (23.1%) and D01F fibre-feature claims (21.3%) form a second tier, with D21H pulp/paper compositions, C08L, C08H, C08J and C13K saccharide-recovery classes trailing behind — each of these smaller classes marks a narrower, more specific claim area rather than a crowded one.
Shares are the percentage of the 553 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Feedstock Flexibility for Textile-Grade Cellulose Fibres with Eureka
This page is one run against one query. Ask Eureka your own question about feedstock flexibility for textile-grade cellulose fibres and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this landscape
Method of producing dissolving pulp from recycled fibrous feedstock
A method of producing dissolving pulp from a recycled fibrous feedstock comprising cellulose, lignin and hemicellulose, with lignin content held between 0.1 and 7% and ash content capped at 3%. The fibrous material undergoes alkaline extraction at roughly 0-25°C to reduce hemicellulose content, followed by an oxidative bleaching step to further cut lignin before recovery of the finished fibre.Filed 2015-08-13 by Infinited Fiber Company Oy — illustrates the compositional-window approach that recurs across recycled-feedstock claims in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | WO2015077807A1 | Process for pretreating reclaimed cotton fibres to be used in the production of moulded bodies from regenerat… | 86 |
| 2 | US4652341A | Accelerated pulping process | 66 |
| 3 | WO2018104330A1 | Cellulose fibers | 62 |
| 4 | WO2010046532A1 | Process of producing xylose and dissolving pulp | 61 |
| 5 | US6254722B1 | Method for making dissolving pulp from paper products containing hardwood fibers | 59 |
| 6 | US20110192560A1 | Process of producing xylose and dissolving pulp | 54 |
| 7 | US7390566B2 | Viscose product | 45 |
| 8 | CN102268833A | 一种农作物秸秆蒸汽爆破预水解硫酸盐法制备溶解浆的方法 | 42 |
| 9 | US20090312536A1 | Process For Producing A Pulp | 42 |
| 10 | WO2012004460A2 | A method and apparatus for manufacturing organic solvents by microbes | 41 |
Citation counts inside a searched corpus favour older filings that have had more time to accumulate citations; treat this table as a signal of influence on the field, not a ranking of current technical importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers say about this field
Three patterns stand out once filing volume, technology mix and geography are read together.
No single company controls the claim space
The leading assignee holds 44 records out of 553, and the top 5 combined reach only 21.9% of all records in scope. That leaves a long tail of single- and few-filing entrants working on feedstock-specific variants, which means freedom-to-operate analysis has to look well past the largest filers.
Activity has eased from its 2017 peak
Filings peaked at 32 in 2017 and have declined since, with the 2021-2024 window showing an 11-filing count against 16 three years earlier. Recent-year assignee momentum data shows several established filers, including two large pulp and chemical groups, recording zero filings in the latest tracked year.
Pulp processing is the dense zone; fibre and saccharide chemistry are thinner
D21C pulp production and treatment appears in nearly two-thirds of the 553 records. Polysaccharide derivatives (C08B, 23.1%) and fibre-feature claims (D01F, 21.3%) are meaningful secondary zones, while saccharide-recovery claims under C13K sit at just 4.9%, suggesting recovery-stream chemistry is comparatively under-filed relative to core pulp treatment.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to feedstock flexibility for textile-grade cellulose fibres, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Lenzing AG | Sodra Skogsagarna Ekonomisk Forening | 9 |
| Aalto University Foundation | University of Helsinki | 6 |
| Bahia Specialty Cellulose | Bahia Specialty Cellulose S.A. | 3 |
| Aalto University Foundation | GRANSTROM TOM | 2 |
| Lenzing AG | SODRA SKOGSAGARNA EKONOMISK FORENING | 1 |
| South China University of Technology | Gannan Normal University | 1 |
| South China University of Technology | Zhongzhi Technology and Culture Development (Jiangsu) Co., Ltd. | 1 |
| South China University of Technology | Donghua University | 1 |
Only 9 co-assignee pairs appear across the dataset, the strongest linking two established pulp producers on 9 shared records — most work in this field is filed by a single assignee rather than through joint filings.
Who is filing, and where the gaps sit
The ranked assignee list spans large pulp and fibre manufacturers, universities and specialty chemical producers, but ownership is dispersed rather than locked up by a handful of names.
Established pulp and fibre producers set the pace
The leading assignee's 44 records and the drop to 18 at fifth place show a moderate gradient rather than a sharp cliff, consistent with several large pulp, viscose and specialty-fibre producers filing steadily rather than one company dominating outright.
Universities and research institutes hold meaningful positions
Several university and academic-institute assignees appear well inside the ranked list, reflecting active work on pretreatment chemistry and enzymatic routes for recycled and non-wood feedstocks alongside industrial filers.
Recent-year activity has gone quiet for established names
Several assignees that appear high in the overall ranking, including large pulp and chemical groups, show zero filings in the latest tracked year, with one filer recording a -100% year-on-year change. This is consistent with the broader 2021-2024 slowdown rather than any single company's retreat.
| Assignee | Recent year | YoY |
|---|---|---|
| South China University of Technology | 1 | -50% |
| Lenzing AG | 0 | — |
| Weyerhaeuser Co. | 0 | — |
| Qilu University of Technology (Shandong Academy of Sciences) | 0 | -100% |
| SODRA SKOGSAGARNA EKONOMISK FORENING | 0 | — |
| Valmet AB | 0 | — |
| Bahia Specialty Cellulose | 0 | — |
| Aalto University Foundation | 0 | — |
Where to take this analysis
The landscape points to a dispersed field with a cooling but still active filing base and a dominant but not exclusive claim zone in pulp treatment.
Map freedom-to-operate against the long tail
With the top 5 assignees holding only 21.9% of records, a freedom-to-operate check needs to cover far more than the largest filers to be reliable.
Run an FTO search in Eureka →Track the under-claimed branches
Saccharide co-recovery and ash-tolerance control show low record counts relative to core pulp treatment — worth monitoring before filing there.
Explore white space in Eureka →Watch for the 2025-2026 filing catch-up
Because publication lags filing by about 18 months, the apparent slowdown in the newest years will partly reverse as more filings publish.
Set up filing alerts in Eureka →Common questions on this landscape
The leading assignee in this 553-record dataset holds 44 records, with the count falling to 18 at fifth place and 13 at tenth place. The top 5 assignees combined account for only 21.9% of all records in scope, and the top 10 for 34.7%, so ownership is spread across a long tail of industrial filers, universities and research institutes rather than concentrated in one or two companies. Anyone assessing this space needs to look well past the largest filers to get a complete competitive picture.
Filing peaked at 32 records in 2017 and has generally eased since, with the 2021-to-2024 window showing an 11-filing count against 16 three years earlier, a -31% change. However, publication lags filing by roughly 18 months, so the very low counts recorded for 2025 and 2026 understate real activity and should not be read as a continuing decline. The honest read is a field that has cooled from its 2017 peak but has not stopped filing.
D21C, covering pulp production and treatment, appears in 65.1% of the 553 records and is by far the densest claim area. Polysaccharide derivative chemistry (C08B, 23.1% of records) and chemical filament or fibre feature claims (D01F, 21.3%) form a clear second tier. Because a single record can carry multiple IPC classes, these percentages add up to more than 100%, and smaller classes like C13K saccharide recovery (4.9%) mark comparatively narrow, less-crowded claim territory.
US20150225901A1, assigned to Infinited Fiber Company Oy, claims a method of producing dissolving pulp from recycled fibrous feedstock with lignin content held between 0.1% and 7% and ash content capped at 3%, using alkaline extraction at roughly 0-25°C followed by oxidative bleaching. It defines a specific compositional window and process sequence rather than the entire recycled-feedstock category, so it constrains filings that fall inside that lignin and ash range with that extraction and bleaching sequence, but leaves room for different compositional windows or alternative pretreatment chemistries. A freedom-to-operate review should compare any new process's lignin, ash and temperature parameters directly against this claim rather than assuming blanket coverage.
The comparatively low record counts in C13K saccharide recovery (4.9% of 553 records) and C08H natural macromolecule derivatives (5.4%) suggest these adjacent chemistries are under-claimed relative to core pulp treatment. Co-filing is also rare across the dataset, with only 9 co-assignee pairs identified, meaning most technical routes are being pursued independently rather than through joint development. Sub-areas like ash-tolerance control in recycled cotton and contaminant carryover in mixed textile waste streams show enough filing activity to be real, but not enough to be considered locked up.
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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.