Blanco Varela et al 2025a - Revision history

Marherna: Marherna moved page Review 422576075047 to Blanco Varela et al 2025a

2025-08-12T10:27:53Z

Marherna moved page Review 422576075047 to Blanco Varela et al 2025a

Tamara blanco at 12:50, 7 August 2025

2025-08-07T12:50:27Z

Tamara blanco at 12:43, 7 August 2025

2025-08-07T12:43:01Z

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Tamara blanco at 01:15, 17 June 2025

2025-06-17T01:15:52Z

Tamara blanco at 08:19, 28 April 2025

2025-04-28T08:19:46Z

Tamara blanco at 08:13, 28 April 2025

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Tamara blanco at 08:11, 28 April 2025

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Tamara blanco at 08:09, 28 April 2025

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Tamara blanco at 08:07, 28 April 2025

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Tamara blanco: Tamara blanco moved page Draft Blanco Varela 652174522 to Review 422576075047

2025-04-23T12:27:52Z

Tamara blanco moved page Draft Blanco Varela 652174522 to Review 422576075047

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 On top, the perspective for the future shows a high increase of the end of life composites due to last generation aircrafts with higher composite content, e.g. A350 (+CFRP fuselage & wing) or  A220 (+CFRP wing), with EoL from 2028 / 2030, as well as the expectation to further composite use in next generation single aisle aircraft as explained in paragraph 1.
-Based on the Airbus Global Market Forecast 2024 [7], the estimated EoL composite waste to be retired between 2023-2043 from passenger aircrafts is 250.000 Tons, 65% from structure and the rest from cabin. Additionally, it can be highlighted that currently, a maximum of 5% of all thermoset composite waste is recycled [8], a figure that can be extrapolated to the aeronautical sector and, in this case, all the recycled composite material is coming from production waste.
+Based on the Airbus Global Market Forecast 2024 [7], the estimated EoL composite waste to be retired between 2023-2043 from passenger aircrafts is 250.000 Tons, 65% from structure and the rest from cabin. Additionally, it can be highlighted that, currently, a maximum of 5% of all thermoset composite waste is recycled [8], a figure that can be extrapolated to the aeronautical sector and, in this case, all the recycled composite material is coming from production waste.
 =3. Opportunities and trends=

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 Regarding industrial eco-efficiency in composite production in terms of energy consumption, we can split between initiatives by materials and part suppliers. Additionally, it is also important to highlight that all of these initiatives will also involve an important benefit to reach the future demanding targets in terms of production rate and cost.
-:* PAN-based carbon fiber production technologies by material suppliers, e.g. microwave heating, which can save around 90% energy in first phase of carbon fiber production, or electrical heating, work on the precursor at molecular level to  steer the carbonization phase towards the lowest temperature range (additives, catalyst,...) , for alternative precursor sourcing ie: lignin/cellulose, the usual costly multiple purification steps of PAN (in total 5), could be replaced only by enzymatic purification…
+:* PAN-based carbon fiber production technologies by material suppliers, e.g. microwave heating, which can save around 90% energy in first phase of carbon fiber production, or electrical heating, work on the precursor at molecular level to steer the carbonization phase towards the lowest temperature range (additives, catalyst,...), alternative precursor sourcing, ie: lignin/cellulose, the usual costly multiple purification steps of PAN (in total 5) could be replaced only by enzymatic purification…
 :* In terms of composite component production by OEMs, key fields are: development of out of autoclave technologies, relaxation of the storage and clean area conditions to work with thermoset prepregs, net shape technologies, fast curing and lay-up materials and technos.

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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 Figure 1. CO<sub>2</sub> amortization time due to 10% weight saving (standard fuel / propulsion energy)</div>
 As these rough estimations are considering classic kerosene propelled vehicles, it is only valid for short to medium term timeframe. But this is even more relevant for next gen aircrafts based on cleaner but costly propulsion energies (SAF or H2), thus, the undesirable initial primary energy invested due to CFRP use will amortize even quicker, with the same 10% weight saving. As a rule of thumb break even is estimated to be well below 2 years, and with regard to the 20-30 years  life this positive impact of CFRP will sum-up 15-50 times higher savings than initial drawbacks.
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 :* '''Epoxy resin: '''the base epoxy monomer comes''' '''from fossil feedstocks, i.e. from chemical intermediaries obtained from benzene, propylene and ammonia, other components of the resin are the hardener, tougheners and additives, as it can be seen in following figure 2 b).
 {|
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 | [[Image:Draft_Blanco Varela_652174522-image4-c.png|center|324px]]
 |}
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 PAN: polyacrylonitrile, PAP: para amino phenol, MDA: 4,4′-methylenedianiline, BPA: bisphenol A, MAP: meta amino phenol, EPI: epichlorohydrin, DDS: 4,4' - Diaminodiphenyl Sulfone </div>
 :* '''Prepreg: '''are obtained from unidirectional carbon fiber or fabrics and epoxy resin with hardener (mono-component), by following processes:
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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 Figure 3. Global Warming Potential of different processes to obtain aeronautical CFRP parts. NCF: non-crimp fabric, TFP: tailored fiber placement, VARI: vacuum assisted resin Infusion, RTM: Resin Transfer Moulding, AFP: automated fiber placement, ATL: automated lay-up, AFPT: advanced fiber placement / in-situ consolidation</div>
 :* AFP + Autoclave processes (either with thermoset or thermoplastic carbon fiber materials) shows the highest GWP. A maximum value of 55.7 kg CO<sub>2</sub>eq / kg part can be obtained for thermoplastic prepreg and 44 kg CO<sub>2</sub>eq / kg part for thermoset prepreg.
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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 Figure 4. Recycling Technologies for composites a) thermoset b) thermoplastic</div>
 But the next key step after recycling is the production of recyclates or secondary materials from recovered or recycled carbon fibers or composites, suitable to obtain new parts (see table 1).

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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-PAN: polyacrylonitrile, PAP: para amino phenol, MDA: 4,4′-methylenedianiline, BPA: bisphenol A, MAP: meta amino phenol, EPI: epichlorohydrin, DDS: 4,4' - Diaminodiphenyl Sulfone. </div>
+PAN: polyacrylonitrile, PAP: para amino phenol, MDA: 4,4′-methylenedianiline, BPA: bisphenol A, MAP: meta amino phenol, EPI: epichlorohydrin, DDS: 4,4' - Diaminodiphenyl Sulfone </div>
 :* '''Prepreg: '''are obtained from unidirectional carbon fiber or fabrics and epoxy resin with hardener (mono-component), by following processes:
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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Figure 3. Global Warming Potential of different processes to obtain aeronautical CFRP parts. NCF: non-crimp fabric, TFP: tailored fiber placement, VARI: vacuum assisted resin Infusion, RTM: Resin Transfer Moulding, AFP: automated fiber placement, ATL: automated lay-up, AFPT: advanced fiber placement / in-situ consolidation.</div>
+Figure 3. Global Warming Potential of different processes to obtain aeronautical CFRP parts. NCF: non-crimp fabric, TFP: tailored fiber placement, VARI: vacuum assisted resin Infusion, RTM: Resin Transfer Moulding, AFP: automated fiber placement, ATL: automated lay-up, AFPT: advanced fiber placement / in-situ consolidation</div>
 :* AFP + Autoclave processes (either with thermoset or thermoplastic carbon fiber materials) shows the highest GWP. A maximum value of 55.7 kg CO<sub>2</sub>eq / kg part can be obtained for thermoplastic prepreg and 44 kg CO<sub>2</sub>eq / kg part for thermoset prepreg.

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 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Figure 2. Simplified processes to obtain aeronautical (a) carbon fiber (b) epoxy resin</div>
+Figure 2. Simplified processes to obtain aeronautical (a) carbon fiber (b) epoxy resin.</div>
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">

← Older revision	Revision as of 10:27, 12 August 2025
(No difference)

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 ==3.2 Substance compliance==
-Environmental regulation organizations, such as ECHA (European Chemicals Agency) with REACH regulation, are progressively more actively working for the safe use of chemicals, which is heavily impacting the aircraft industry in recent years (e.g. chromates). The aviation industry must comply with the airworthiness requirements derived from EU Regulation No 216/2008 in Europe - EASA (European Aviation Safety Agency), and with similar airworthiness requirements in all countries where aeronautical products are sold. All components, from seats and galleys to bolts, equipment, materials and processes incorporated in an aircraft fulfil specific functions and must be qualified and certified. If a substance used in a material, process, component or equipment needs to be changed, an extensive process has to be followed in order to be compliant with the airworthiness requirements. In this frame, a cooperation memo between ECHA and EASA has been published in 2017 [9] to establish a direct channel and collaboration between both entities.
+Environmental regulation organizations, such as ECHA (European Chemicals Agency) with REACH regulation, are progressively more actively working for the safe use of chemicals, which is heavily impacting the aircraft industry in recent years (e.g. chromates). The aviation industry must comply with the airworthiness requirements derived from EU Regulation No 216/2008 in Europe - EASA (European Aviation Safety Agency), and with similar airworthiness requirements in all countries where aeronautical products are sold. All components, from seats and galleys to bolts, equipment, materials and processes incorporated in an aircraft fulfil specific functions and must be qualified and certified. If a substance used in a material, process, component or equipment needs to be changed, an extensive process has to be followed in order to be compliant with the airworthiness requirements. In this frame, a cooperation memo between ECHA and EASA has been published in 2017 to establish a direct channel and collaboration between both entities [9].
 Thus, in order to be compliant with this regulation, several anticipation and derisking activities have arisen, especially in the composite area, to secure the aviation industry. Current substances under REACH radar are: formaldehyde (used to produce phenolic resin used in interior composites), BPA - Bisphenol A (precursor to obtain epoxy resin), PFAS - per- and poly-fluoroalkyl substances (present in auxiliary materials to produce composites, like release films), etc. Moreover, for those materials impacted by the current main proposals launched, PFAS and BPA, advocacy activities are ongoing. Finally, it is also key to pay attention to substance compliance for biosourced composites, since bioderived does not mean substance compliant.

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 The biobased chemical industry is a fast growing sector. In fact, from 2008 to 2019, the biobased chemicals and plastics sector in the EU-28 has increased its turnover by 68 % [7]. As summarized in paragraph 2.1, today's composite materials rely on the petrochemical industry to produce carbon fibers and resins. But it is demonstrated that carbon fibers and resins can also be obtained from sustainable biosources or biomass, which involve a positive environmental impact and can even contribute with a negative carbon footprint. Among the biosourced composites, drop-in (same material from biosources) are always preferred versus look-alike (different materials, from different biosourced molecules or raw materials), since this last approach can lead to a performance decrease, therefore, the increase of in-service footprint will be the critical consequence. So the overall carbon footprint for any technology switch has to be carefully considered.
-In order to secure the use of biosourced feedstocks, raw materials and intermediary chemicals in the supply chain (resins and/or fibers), a chain of custody model needs to be implemented.  Among the different models, the one which is fully recognized in the chemical industry and, then, can be applicable to composites is the mass balance. This model involves the mixing of biobased or circular feedstocks with standard fossil based feedstocks at the beginning production process and allocate or attribute them to one or several final materials or products, thus, this approach does not guarantee a specific biosourced or circular content in a final material lot. This calculation-based principle offers multiple advantages, mainly the reduction of greenhouse gas emissions and fossil feedstocks, while the final products or materials remain the same. Then, the mass balancing easily enables the drop-in approach but it is not mandatory for it and must not be mixed up with it. Additionally, a mass balance certification of the material, e.g. carbon fiber or resin, is needed by an independent body [9].
+In order to secure the use of biosourced feedstocks, raw materials and intermediary chemicals in the supply chain (resins and/or fibers), a chain of custody model needs to be implemented.  Among the different models, the one which is fully recognized in the chemical industry and, then, can be applicable to composites is the mass balance. This model involves the mixing of biobased or circular feedstocks with standard fossil based feedstocks at the beginning production process and allocate or attribute them to one or several final materials or products, thus, this approach does not guarantee a specific biosourced or circular content in a final material lot. This calculation-based principle offers multiple advantages, mainly the reduction of greenhouse gas emissions and fossil feedstocks, while the final products or materials remain the same. Then, the mass balancing easily enables the drop-in approach but it is not mandatory for it and must not be mixed up with it. Additionally, a mass balance certification of the material, e.g. carbon fiber or resin, is needed by an independent body [8].
 Main challenges to be highlighted in the implementation of mass balance carbon fibers and epoxy resins: likely final material cost increase associated with the availability of biosources, value assessment for the OEM or final user, secure traceability and control of the materials.
@@ Line 101: / Line 101: @@
 ==3.2 Substance compliance==
-Environmental regulation organizations, such as ECHA (European Chemicals Agency) with REACH regulation, are progressively more actively working for the safe use of chemicals, which is heavily impacting the aircraft industry in recent years (e.g. chromates). The aviation industry must comply with the airworthiness requirements derived from EU Regulation No 216/2008 in Europe - EASA (European Aviation Safety Agency), and with similar airworthiness requirements in all countries where aeronautical products are sold. All components, from seats and galleys to bolts, equipment, materials and processes incorporated in an aircraft fulfil specific functions and must be qualified and certified. If a substance used in a material, process, component or equipment needs to be changed, an extensive process has to be followed in order to be compliant with the airworthiness requirements. In this frame, a cooperation memo between ECHA and EASA has been published in 2017 [10] to establish a direct channel and collaboration between both entities.
+Environmental regulation organizations, such as ECHA (European Chemicals Agency) with REACH regulation, are progressively more actively working for the safe use of chemicals, which is heavily impacting the aircraft industry in recent years (e.g. chromates). The aviation industry must comply with the airworthiness requirements derived from EU Regulation No 216/2008 in Europe - EASA (European Aviation Safety Agency), and with similar airworthiness requirements in all countries where aeronautical products are sold. All components, from seats and galleys to bolts, equipment, materials and processes incorporated in an aircraft fulfil specific functions and must be qualified and certified. If a substance used in a material, process, component or equipment needs to be changed, an extensive process has to be followed in order to be compliant with the airworthiness requirements. In this frame, a cooperation memo between ECHA and EASA has been published in 2017 [9] to establish a direct channel and collaboration between both entities.
 Thus, in order to be compliant with this regulation, several anticipation and derisking activities have arisen, especially in the composite area, to secure the aviation industry. Current substances under REACH radar are: formaldehyde (used to produce phenolic resin used in interior composites), BPA - Bisphenol A (precursor to obtain epoxy resin), PFAS - per- and poly-fluoroalkyl substances (present in auxiliary materials to produce composites, like release films), etc. Moreover, for those materials impacted by the current main proposals launched, PFAS and BPA, advocacy activities are ongoing. Finally, it is also key to pay attention to substance compliance for biosourced composites, since bioderived does not mean substance compliant.
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 Vitrimers, which are associative covalent adaptive networks (CAN) based on exchangeable dynamic covalent bonds, have been identified as potential candidates because they offer a promising solution by enabling re-processability while maintaining the main advantages of current thermoset resin (processing conditions/temperature, means, mechanical properties...). Although several vitrimers are arising in the market, they do not meet yet the aeronautical requirements, e.g. in terms of glass transition temperature.
-Therefore, CIDETEC in collaboration with Airbus are developing vitrimers for aircraft application from 2021, based on dynamic aromatic disulfide bonds. Currently, this research is still ongoing by means of producing a 100% dynamic vitrimer epoxy formulation with competitive mechanical properties and exploring their capabilities to be shipped, stored and used at >0 ºC or ultimately at room temperature for unlimited time, which we have called enduring prepreg (unlike thermoset materials, which need -18ºC storage and have limited shelf life), minimising the production energy consumption, then, positioning them closer to thermoplastic resins [7].
+Therefore, CIDETEC in collaboration with Airbus are developing vitrimers for aircraft application from 2021, based on dynamic aromatic disulfide bonds. Currently, this research is still ongoing by means of producing a 100% dynamic vitrimer epoxy formulation with competitive mechanical properties and exploring their capabilities to be shipped, stored and used at >0 ºC or ultimately at room temperature for unlimited time, which we have called enduring prepreg (unlike thermoset materials, which need -18ºC storage and have limited shelf life), minimising the production energy consumption, then, positioning them closer to thermoplastic resins [10].
 =4. Recommendations=
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 =5.   Acknowledgments=
-Authors would like to acknowledge the contribution to this article of Uwe Beier, from Airbus Central Research Team (CRT), and David Tilbrook, from Hexcel, for providing key information and insights. Also, thanks to Nerea Markaide and Alaitz Rekondo from CIDETEC regarding the development of aeronautical vitrimers in collaboration with Airbus. This development was started in OPTIMUS project, funded by the Spanish funding body CDTI (‘Centro para el Desarrollo Tecnológico Industrial’) with grant number MIG-20211010, through the 2021 call for granting funds for Science and Innovation Missions (‘Misiones’), within the Recovery, Resilience and Transformation Plan (funded by the Next Generation EU funds – Recovery and Resilience Mechanism) and the State Program to catalyze the Innovation and Business Leadership of the State Plan for Scientific and Technical Research and Innovation 2021-2023. Vitrimer resin development between Airbus and CIDETEC is currently ongoing in the EconCARBon project funded by CDTI with support from the Ministry of Science and Innovation under grant number MIG-20241002, as part of the 2024 call for the Missions of Science and Innovation Program. It is also integrated into the Scientific, Technical, and Innovation Research Plan 2024-2027, under the Recovery, Transformation, and Resilience Plan.
+Authors would like to acknowledge the contribution to this article of Uwe Beier, from Airbus Central Research & Technology (CRT), and David Tilbrook, from Hexcel, for providing key information and insights. Also, thanks to Nerea Markaide and Alaitz Rekondo from CIDETEC regarding the development of aeronautical vitrimers in collaboration with Airbus. This development was started in OPTIMUS project, funded by the Spanish funding body CDTI (‘Centro para el Desarrollo Tecnológico Industrial’) with grant number MIG-20211010, through the 2021 call for granting funds for Science and Innovation Missions (‘Misiones’), within the Recovery, Resilience and Transformation Plan (funded by the Next Generation EU funds – Recovery and Resilience Mechanism) and the State Program to catalyze the Innovation and Business Leadership of the State Plan for Scientific and Technical Research and Innovation 2021-2023. Vitrimer resin development between Airbus and CIDETEC is currently ongoing in the EconCARBon project funded by CDTI with support from the Ministry of Science and Innovation under grant number MIG-20241002, as part of the 2024 call for the Missions of Science and Innovation Program. It is also integrated into the Scientific, Technical, and Innovation Research Plan 2024-2027, under the Recovery, Transformation, and Resilience Plan.
 =6.   Bibliography=
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 [6] [https://aircraft.airbus.com/en/newsroom/news/2022-11-end-of-life-reusing-recycling-rethinking https://aircraft.airbus.com/en/newsroom/news/2022-11-end-of-life-reusing-recycling-rethinking]
-[7] E. del Puerto-Nevado, T. Blanco-Varela, N. Markaide, A. Ruiz de Luzuriaga, A.M. Salaberria. Aeronautical Vitrimer Resin for Prepreg Application. ECCM21 – 21st European Conference on Composite Materials
+[7] Olaf Porc, Nicolas Hark, Michael Carus (nova-Institut), Dr. Dirk Carrez (BIC), [https://drive.google.com/file/d/1wuBlGON7aXI9x8Hz59wT27Eb7S2YPBdW/view?usp=share_link European Bioeconomy in Figures 2008–2019,] October 2022
-[8] Olaf Porc, Nicolas Hark, Michael Carus (nova-Institut), Dr. Dirk Carrez (BIC), [https://drive.google.com/file/d/1wuBlGON7aXI9x8Hz59wT27Eb7S2YPBdW/view?usp=share_link European Bioeconomy in Figures 2008–2019,] October 2022
+[8]  [https://www.iscc-system.org/certification/chain-of-custody/mass-balance/ https://www.iscc-system.org/certification/chain-of-custody/mass-balance/]
-[9]  [https://www.iscc-system.org/certification/chain-of-custody/mass-balance/ https://www.iscc-system.org/certification/chain-of-custody/mass-balance/]
+[9] [https://echa.europa.eu/-/echa-and-easa-signed-an-agreement-of-cooperation https://echa.europa.eu/-/echa-and-easa-signed-an-agreement-of-cooperation]
-[10] [https://echa.europa.eu/-/echa-and-easa-signed-an-agreement-of-cooperation https://echa.europa.eu/-/echa-and-easa-signed-an-agreement-of-cooperation]
+[10] E. del Puerto-Nevado, T. Blanco-Varela, N. Markaide, A. Ruiz de Luzuriaga, A.M. Salaberria. Aeronautical Vitrimer Resin for Prepreg Application. ECCM21 – 21st European Conference on Composite Materials

← Older revision	Revision as of 12:27, 23 April 2025
(No difference)