Out of Autoclave Composite Curing Technology 2026
Out-of-Autoclave Composite Curing Technology Landscape
OoA composite curing is maturing from niche research into primary production for aerospace and defense. This dataset spans 1985–2026 across five distinguishable sub-domains and multiple jurisdictions.
From Vacuum Bags to Smart Susceptors: The OoA Curing Landscape
Out-of-autoclave (OoA) composite curing substitutes the 5–7 bar pressures of conventional autoclave vessels with vacuum compaction, resin infusion, embedded heating, induction fields, and shape-conformal enclosures. The field spans at least five distinguishable sub-domains: dual vacuum bag processing, liquid resin infusion variants (VARTM, VERITy), self-heated tooling, shape-adapted miniature autoclave geometries, and advanced OoA resin system development.
The central technical challenge across all OoA approaches is achieving low void content and high fiber volume fraction using vacuum-only compaction (typically ≤1 bar) — properties that conventional autoclave processing delivers through high pressure. A 2022 literature review confirms that standard autoclave-free processes deliver lower fiber volume fractions, producing resin-rich volumes that compromise structural performance.
The innovation timeline in this dataset spans from 1985 (Rolls-Royce prepreg molding) through 2026 (Boeing induction susceptor patent), covering approximately four decades. The most recent filings (2022–2026) signal a shift toward automation integration with AGV-driven in-line autoclaves, smart susceptor induction curing, and reusable bagging infrastructure as the leading technical directions.
In this dataset, The Boeing Company accounts for the largest single filing cluster with at least 30 distinct patent records across US, EP, CA, WO, and BR jurisdictions. Airbus Operations S.L. holds 4 records in retrieved records, while CSIR-NAL and Hindustan Aeronautics Limited each contribute to India’s growing national aerospace composite IP base. No pure-play OoA equipment suppliers appear as patent assignees in this dataset.
Filing Trends and Technology Cluster Distribution
Analysis of retrieved patent records reveals concentrated filing activity across four major technology clusters, with a clear acceleration in automation-focused approaches from 2022 onward.
OoA Technology Cluster Patent Distribution (Dataset Snapshot)
In this dataset, the dual/double vacuum bag cluster and nacelle/shape-conformal curing cluster each account for the largest share of Boeing’s filings, while liquid resin infusion (VERITy/VARTM) represents the primary non-Boeing cluster from CSIR-NAL.
↗ Click bars to exploreOoA Patent Filing Activity by Era (Dataset Snapshot)
In this dataset, filing activity accelerated significantly in the 2010–2015 consolidation era driven by Boeing’s dual-vacuum cluster, with a second acceleration in 2022–2026 reflecting automation and susceptor-based OoA approaches.
↗ Click bars to exploreKey OoA Curing Application Domains Across Aerospace and Defense
OoA composite curing methods are being qualified and deployed across aerospace primary structures, MRO field repair, rotorcraft, business aviation, and defense — with each domain presenting distinct requirements for void content, scale, and field deployability.
Aerospace Primary Structures
OoA processes are being qualified for wing skins, spars, ribs, fuselage panels, and nacelles. CSIR-NAL’s VERITy process has been demonstrated on a full co-cured wing test box, while Karem Aircraft’s US 2014 patent explicitly cites MTM-44 and MTM-45 OoA resin systems as approved for primary aircraft structure. The Clean Sky 2 AirGreen 2 program (2018) validated OoA for next-generation turboprop outer wing boxes.
Primary StructureAerospace MRO and Field Repair
Airbus Operations’ bonded repair system (EP 2018) and dual-bag curing system (EP 2018, US 2019) address maintenance, repair, and overhaul scenarios where damaged structure cannot be moved to an autoclave. Sikorsky Aircraft’s composite repair method (US 2018) targets low-temperature field-curable repairs with constrained thermal profiles to protect surrounding systems and coatings.
MRO / Field RepairRotorcraft and Business Aviation
The multi-zone self-heated tooling literature (2020) explicitly targets business jet lower wing stiffened panels, using embedded heating fabric for zone-controlled temperature profiles. Karem’s double-vacuum OoA patent (US 2014) references resin systems tested on rotorcraft-relevant geometries, and Sikorsky Aircraft (US 2018) contributes rotorcraft-specific repair methodologies.
Rotorcraft / Business JetDefense and Space Structures
The US Navy’s multiscale composite material patent (US 2024) describes porous network architectures enabling void-free composite fabrication entirely without autoclave or vacuum pressure, targeting defense-grade structural materials. This approach addresses the fundamental OoA void problem through materials architecture rather than process pressure.
Defense / SpaceKey Patent Assignees in OoA Composite Curing (Retrieved Records)
In this dataset, The Boeing Company accounts for the largest filing cluster with at least 30 distinct patent records across US, EP, CA, WO, and BR jurisdictions. Airbus Operations S.L. holds 4 records in retrieved records, with CSIR-NAL, Hindustan Aeronautics Limited, and several others each contributing smaller clusters.
Top OoA Assignees by Filing Count — In Retrieved Records (Dataset Snapshot)
↗ Click bars to exploreThe Boeing Company
In this dataset, Boeing holds at least 30 distinct patent records spanning US, EP, CA, WO, and BR jurisdictions from 1985 through 2026. Technology areas include double vacuum cure processing, composite nacelle curing, in-line autoclave adapted to preform geometry with AGV integration, induction heating with smart susceptors, cure growth control apparatus, reusable composite curing systems, and non-vented bladder curing. The most recent Boeing filing in this dataset is a 2026 US grant on curing composites out-of-autoclave using induction heating with smart susceptors.
United StatesAirbus Operations S.L.
Airbus Operations S.L. holds 4 records in retrieved records, filed across EP and US jurisdictions from 2008 through 2019. Key patents cover OoA manufacturing tooling (US 2008, EP 2014), a dual-bag system and method for curing polymer matrix composite parts in manufacturing and repair (EP 2018, US 2019), and a field-deployable system for out-of-autoclave bonded repairs (EP 2018) incorporating a heating source and perforated bulkhead for in-situ aircraft repair.
Spain — ES / EUFour Forward Vectors in OoA Composite Curing (2022–2026)
The most recent filings in this dataset (2022–2026) signal four clear technical directions: induction heating with smart susceptors, AGV-integrated in-line autoclave for high-rate manufacturing, reusable curing infrastructure, and multiscale material architectures for void-free OoA.
Induction Heating with Smart Susceptors
Boeing’s provisional (August 2022) and granted applications (US 2024, US 2026) introduce a dimensional control structure with a lattice-and-casing architecture that maintains part geometry while induction heating delivers uniform cure. The smart susceptor approach uses temperature-self-limiting susceptor materials for precise, scalable OoA curing of large composite panels previously requiring autoclave consolidation. This cluster is still in active prosecution as of 2026.
AGV-Integrated In-Line Autoclave for High-Rate Flow
Boeing’s in-line autoclave patents (EP 2022, US 2022, US 2023, EP 2024) describe autonomous guided vehicle (AGV)-driven mandrels that seal into a geometry-matched pressure chamber, enabling continuous-flow production-line architectures. The 2024 EP publication describes a factory boundary between clean room and assembly environments within the system. This approach retains pressure consolidation quality while eliminating large-vessel capital cost and energy inefficiency.
Dual Vacuum Bag vs. Liquid Resin Infusion (VERITy): OoA Process Comparison
Click any row to explore further.
| Dimension | Dual / Double Vacuum Bag | Liquid Resin Infusion (VERITy / VARTM) |
|---|---|---|
| Differential pressure between inner and outer vacuum bags draws volatiles from resin before gelation | Dry fiber preform infused with catalyzed resin under vacuum-driven differential pressure, then additional cure pressure applied | N/A |
| Vacuum-only (≤1 bar); no autoclave pressure required | VERITy hybridizes VARTM with pressurized cure to approach autoclave-grade compaction | N/A |
| The Boeing Company (US 2011, CA 2011, EP 2012, US 2017, CA 2019); Airbus Operations S.L. (EP 2018, US 2019); Karem Aircraft (US 2014) | Council of Scientific & Industrial Research / CSIR-NAL (IN 2012, IN 2020) | N/A |
| Aircraft structural components including nacelles, fuselage panels, wing structures | Full co-cured wing test box (CSIR-NAL VERITy demonstration) | N/A |
| Airbus dual-bag system explicitly adapted for in-situ repair on installed aircraft (EP 2018, US 2019) | Not described for field repair in retrieved records | N/A |
| Perforated bulkhead between chambers enables controlled gas evacuation while preserving compaction force | Additional cure pressure step compensates for vacuum-only compaction limitations of standard VARTM | N/A |
| 8 records in this dataset (dual/double vacuum bag cluster) | 3 records in this dataset (VERITy / liquid resin infusion cluster) | N/A |
Frequently Asked Questions: Out-of-Autoclave Composite Curing
Out-of-autoclave (OoA) composite curing encompasses manufacturing processes that produce high-performance fiber-reinforced polymer composites without reliance on a conventional pressurized autoclave vessel. Alternative compaction and heating mechanisms include vacuum pressure, resin infusion under controlled differential pressure, embedded or applied heating elements, induction fields, microwave energy, and shape-conformal enclosures.
The core technical challenge is achieving low void content and high fiber volume fraction using vacuum-only compaction (typically ≤1 bar) or partial-pressure alternatives. Conventional autoclave processing uses 5–7 bar pressure to achieve these properties. Standard autoclave-free processes deliver lower fiber volume fractions, producing resin-rich volumes that compromise structural performance, as noted in a 2022 literature review.
The five distinguishable sub-domains identified in this dataset are: (1) double or dual vacuum bag processing, (2) liquid resin infusion variants such as VARTM and VERITy, (3) self-heated tooling and embedded susceptor systems, (4) shape-adapted or inline miniature autoclave geometries, and (5) advanced OoA resin system development.
VERITy (Vacuum Enhanced Resin Infusion Technology) is a proprietary process developed by CSIR-NAL (Council of Scientific & Industrial Research — National Aerospace Laboratories, India). It hybridizes VARTM with pressurized cure to manufacture large co-cured aerospace substructures, including a demonstrated full co-cured wing test box, at lower cost than prepreg/autoclave routes. CSIR-NAL holds two IN-jurisdiction patents (2012, 2020) covering co-cured composite structures manufactured using this process.
Boeing’s most recent filings in this dataset are a 2026 US grant on curing composites out-of-autoclave using induction heating with smart susceptors (provisional filed August 2022), a 2024 EP publication on the in-line autoclave adapted to preform geometry incorporating AGV transport, and a 2024 EP publication on a reusable composite curing system addressing single-use vacuum bag waste.
Boeing’s in-line autoclave patents describe a mandrel-scale pressure chamber formed by sealing the layup mandrel into a contour-matched autoclave bore, with AGV transport enabling continuous-flow production. Unlike conventional OoA, this approach retains pressure consolidation quality while eliminating large-vessel capital cost and energy inefficiency, positioning it as a high-rate manufacturing enabler rather than a pressure-free process.
Data and insights on this page are based on a limited patent and literature dataset and are for reference only. Figures may not represent the complete technology landscape.