Pultruded Spar Caps Patents: Who Leads, Trends & Gaps 2026
- One filer dominates. the leading assignee holds 11 of the ranked filings against a fifth-place holder of just 1, with a long tail of individual inventors alongside it.
- Filing has gone quiet since the 2018 peak. activity peaked at 7 records in 2018 and had fallen back to zero at the 2022 midpoint, with no rebound through the most recent full year.
- Claims cluster in plastics shaping, not turbine-specific classes. 66.7% of the 12 records in scope sit in B29C (shaping of plastics), more than the 50.0% classified directly under F03D wind turbines.
What pultruded spar cap patents actually cover
Pultruded spar caps are the load-carrying planks pulled through a die and stacked into a wind blade’s main structural spar, replacing hand-laid infusion with a continuous, fibre-aligned profile. The patent activity in this dataset concentrates on how those planks are positioned, bonded and infused inside the blade mould rather than on the pultrusion process itself — claims target plank stacking, bondline quality between planks, fibre waviness control, and the resin infusion sequence used to eliminate interlaminar defects. That distinction matters for freedom-to-operate work: a filer working on the die and fibre-forming side of pultrusion is operating in different claim territory to one working on how the finished planks go into the blade.
The 12 records in scope span receiving offices in the United States, Europe, India, the WIPO PCT route and Austria, with US filings the largest single group. That spread points to a technology still being protected regionally around specific blade manufacturers rather than defended as a single global platform.
Filing trend and technology composition
The trend and class data below are drawn directly from the 12 published records in scope; publication lags filing by roughly 18 months, so the most recent year is understated by definition.
A 2018 peak followed by a flat-to-declining trend
Filing rose to a peak of 7 records in 2018, then fell away; by the 2022 midpoint the annual count was zero, and it has not recovered through to the most recent year (also 0, though partial). This is a small, cyclical filing population rather than a steadily growing one.
Plastics-shaping classes outweigh turbine-specific ones
B29C (shaping of plastics) covers 66.7% of the 12 records, ahead of F03D (wind turbines) at 50.0%. B63H (marine propulsion) appears in 33.3% of records, reflecting pultrusion's shared use in marine composite structures; B29L and B29D each cover a smaller slice. Because records can carry more than one class, these shares add up to over 100% of the record total — they are not mutually exclusive buckets.
Shares are the percentage of the 12 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Pultruded Spar Caps for Wind Blades with Eureka
This page is one run against one query. Ask Eureka your own question about pultruded spar caps for wind blades and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited filings in this dataset
WO2024213115A1 — Integrated infusion process for pultruded wind blade spar caps
The filing describes an infusion process for the pultruded main spar of a wind blade: flow-blocking barriers are placed on the flow mesh above the spar region, positioned symmetrically to the butt joints, with dedicated resin injection lines between each pair of barriers. Injection ports open sequentially as the resin front reaches each barrier and close once the spar region is fully infused, before the whole blade is heat-cured. The stated aim is eliminating interlaminar glass-fibre infusion defects and improving fatigue performance between spar cap layers.Filed by Luoyang Sunrui Wind Turbine Blade Co., Ltd., 2024-10-17. Original title machine-translated from Chinese.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20200080542A1 | Positioning profiles for pultrusions in wind blade spar caps | 11 |
| 2 | US11041478B2 | Positioning profiles for pultrusions in wind blade spar caps | 4 |
| 3 | WO2024213115A1 | 一种风电叶片拉挤主梁一体灌注工艺方法 | 2 |
| 4 | US11598309B2 | Positioning profiles for pultrusions in wind blade spar caps | 2 |
| 5 | US20210340949A1 | Positioning profiles for pultrusions in wind blade spar caps | 1 |
| 6 | WO2020055396A1 | Positioning profiles for pultrusions in wind blade SPAR caps | 1 |
Citation counts inside a searched corpus favour older filings; treat the ranking as a signal of influence within this dataset, not 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. Publication numbers are shown where the record carries one (6 of 6 rows); clicking a row searches Eureka by that number.
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Browse MCP servers →What the filing pattern signals
Three things stand out once the ranking, the trend and the class data are read together.
One filer, a thin field behind it
The ranked leader holds 11 records against a fifth-place holder of just 1, with individual inventors occupying several of the remaining slots. That is a narrow competitive set for a structural blade component with clear cost and performance stakes.
Activity has cooled since 2018
Filing peaked at 7 records in 2018 and had dropped to zero by 2022, with no recovery through the latest year. Because publication lags filing by around 18 months, the most recent year understates true activity, but the multi-year decline before that is real.
Claims sit closer to plastics processing than turbine engineering
Two-thirds of records classify under B29C shaping of plastics, ahead of the 50.0% classified under F03D wind turbines. A third also touch B63H marine propulsion, showing pultrusion claim language is shared across blade and marine composite applications.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to pultruded spar caps for wind blades, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| TPI Composites, Inc. | WARCHOL NICHOLAS | 1 |
| TPI Composites, Inc. | VILLAR MICHAEL | 1 |
| TPI Composites, Inc. | MONIE WAYNE G | 1 |
| WARCHOL NICHOLAS | VILLAR MICHAEL | 1 |
| WARCHOL NICHOLAS | MONIE WAYNE G | 1 |
| VILLAR MICHAEL | MONIE WAYNE G | 1 |
Only 6 co-assignee pairs appear across the dataset, each linking the leading company with a named individual inventor rather than with another corporate filer — there is no visible joint-development cluster to watch here.
Who is filing, and what they are leaving open
The ranking is short and led by one company, but the class data points to several adjacent areas with little dedicated claim coverage.
The dominant filer holds the core plank-positioning claims
The leading assignee's filings, including the most-cited records in this dataset, centre on positioning profiles for pultrusions inside the spar cap — plank stacking and alignment rather than the pultrusion process itself.
The tail is individual inventors, not competing manufacturers
Below the leader and a second corporate filer, the remaining ranked entries are named individuals rather than blade manufacturers, suggesting limited direct corporate competition for the core claims to date.
Protection is regional, not globally unified
United States filings lead the receiving-office count, followed by Europe, with India and the WIPO PCT route each contributing two records. No single office dominates the way the assignee ranking is dominated by one company.
| Assignee | Recent year | YoY |
|---|---|---|
| TPI Composites, Inc. | 0 | — |
| Xiamen Sunrui Composite Materials Technology Co., Ltd. | 0 | — |
| WARCHOL NICHOLAS | 0 | — |
| VILLAR MICHAEL | 0 | — |
| MONIE WAYNE G | 0 | — |
Where to take this next
The dataset flags a narrow, one-firm-led field with cooling filing activity — the next steps depend on whether the goal is freedom-to-operate, competitive tracking, or spotting where to file.
Run a freedom-to-operate check on plank-positioning claims
Before designing a spar cap layup or infusion sequence, check the leading assignee's positioning-profile family in detail — it accounts for the majority of the ranked filings and the most-cited records in this dataset.
Explore the full filing family in Eureka →Watch for a filing rebound as blade lengths grow
Filing fell to zero by the 2022 midpoint; given the roughly 18-month publication lag, it is worth re-checking this dataset in the next cycle to see whether longer-blade programmes have restarted activity.
Set up ongoing monitoring in Eureka →Test the under-claimed branches against your own designs
Bondline quality control and fibre waviness detection show up in the record set without a concentrated claim holder — map your own process against these before assuming the space is open.
Compare claim scope in Eureka →Common questions on pultruded spar cap patents
One assignee leads this dataset with 11 of the 12 ranked patent records, well ahead of the next-ranked holder at a single filing. That leader's portfolio centres on positioning profiles for pultrusions inside the spar cap, including several of the most-cited filings in the set. The remaining ranked entries are largely individual inventors rather than competing blade manufacturers, so the competitive field for this specific claim territory is narrow rather than broad.
Filing peaked at 7 records in 2018 and had declined to zero by the 2022 midpoint, with no recovery through the most recent year on record. Because publication typically lags filing by around 18 months, the very latest year understates real activity, but the multi-year decline before that reflects an actual slowdown, not a data artefact. Anyone tracking this space should expect a gap and re-check filings from the last 12-18 months once they publish.
Most records classify under B29C, the shaping-of-plastics class, at 66.7% of the 12 records in scope, ahead of the wind-turbine-specific F03D class at 50.0%. A third of records also touch B63H, marine propulsion, reflecting that pultrusion claim language is often shared between blade and marine composite structures. Because a single record can carry multiple classes, these percentages overlap rather than sum to 100%.
WO2024213115A1 claims an integrated infusion process for a wind blade's pultruded main spar, using flow-blocking barriers and sequenced injection lines to eliminate interlaminar glass-fibre defects between stacked pultruded planks. It was filed by Luoyang Sunrui Wind Turbine Blade Co., Ltd. in 2024. Anyone designing a spar cap infusion sequence with similarly placed flow barriers and sequential port opening should map their process against this filing's specific claim language before assuming clearance.
The class data points to bondline quality control between spar cap and shear web, fibre waviness detection during plank stacking, and integrated resin flow sequencing as areas that appear in the record set without a concentrated claim holder. That is not proof the space is empty, since a short dataset can miss adjacent filings classified elsewhere, but it does mean the usual freedom-to-operate check is worth running rather than skipping. Marine-to-blade transfer of pultrusion process claims is another branch worth checking given the overlap with B63H.
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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.