Calero et al 2023a - Revision history

Marherna: Marherna moved page Review 112957926513 to Calero et al 2023a

2023-12-05T12:05:06Z

Marherna moved page Review 112957926513 to Calero et al 2023a

Tamara blanco at 10:19, 4 September 2023

2023-09-04T10:19:41Z

Tamara blanco: Incluidas las revisiones requeridas: abstract en español, eliminado el proyecto de financiación en la introducción (solo en agradecimientos), y sustituida la palabra project del artículo por trabajo, actividad...

2023-09-04T10:15:37Z

Incluidas las revisiones requeridas: abstract en español, eliminado el proyecto de financiación en la introducción (solo en agradecimientos), y sustituida la palabra project del artículo por trabajo, actividad...

Tamara blanco at 12:57, 7 June 2023

2023-06-07T12:57:10Z

Tamara blanco at 12:42, 7 June 2023

2023-06-07T12:42:10Z

Tamara blanco at 03:23, 30 May 2023

2023-05-30T03:23:10Z

Tamara blanco at 03:14, 30 May 2023

2023-05-30T03:14:12Z

Tamara blanco at 03:05, 30 May 2023

2023-05-30T03:05:12Z

Tamara blanco at 16:10, 25 May 2023

2023-05-25T16:10:17Z

Tamara blanco at 15:55, 25 May 2023

2023-05-25T15:55:37Z

Show changes

@@ Line 42: / Line 42: @@
 The main motivation of this work was to evaluate a commercially available solution, non-woven mats, to recycle aeronautical dry carbon fiber scrap for aeronautical or non-aeronautical applications. These materials have a random short fiber orientation leading to final composites with poor fiber volume content and, then, low performance versus the state of art continuous and oriented carbon fiber aeronautical composites.
-The main focus was the production, study and evaluation of a recycled non-woven mat from dry carbon fiber fabric scrap, which is generated during the RTM production of aeronautical composite parts. The production of this non-woven mat was performed by an external company, STFI. Then, RTM process with standard aeronautical liquid resin was used to obtain composites with a carbon fiber volume content, and then mechanical properties, as high as possible. The produced flat composite panels were, then, characterized from mechanical point of view. Additionally, in order to reach higher mechanical performance, above all in terms of impact resistance, hybrid composite panels combining the recycled non-woven mat and a standard dry carbon fiber fabric were produced and characterized.
+Then, the focus of this activity was the production, study and evaluation of a recycled non-woven mat from dry carbon fiber fabric scrap, which is generated during the RTM production of aeronautical composite parts. The production of this non-woven mat was performed by an external company, STFI. Then, RTM process with standard aeronautical liquid resin was used to obtain composites with a carbon fiber volume content, and then mechanical properties, as high as possible. The produced flat composite panels were, then, characterized from mechanical point of view. Additionally, in order to reach higher mechanical performance, above all in terms of impact resistance, hybrid composite panels combining the recycled non-woven mat and a standard dry carbon fiber fabric were produced and characterized.
 ==2. Recycled carbon fiber non-woven mat production ==

@@ Line 19: / Line 19: @@
 ==ABSTRACT==
 Our latest generation aircraft are more efficient by design, lighter and emit on average 25% less CO2 than previous generation aircrafts. Lightweight materials like composites have contributed significantly to reach the current emissions levels, like the A350 with more than 50% of structural weight made of composites.
@@ Line 24: / Line 26: @@
 However, composites drive also the environmental footprint of the aircraft life-cycle without considering the operational phase, involving currently important drawbacks in terms of energy consumption and waste recycling. The transition towards a composite circular economy needs to be anticipated due to the aviation sector de-carbonization challenge as well as the regulation evolution. This transition will be leveraged by several elements, being the composite recycling one of the most important, due to the need to transform the composite waste from production and end of life into new added value materials. For this, the development of efficient composite recycling technologies to not only recover energy during incineration but also high value recycled carbon fibers and semi-products are needed.
-This project was focused on the recycling of dry carbon fiber scrap, which can proceed from part production by infusion technologies (e.g. RTM) or from pyrolysis of end of life composite part. The approach was to obtain a non-woven mat from the dry fiber scrap, following a mechanical process, which was, then, fully characterized to identify potential applications in aeronautical field. Different approaches of hybridization of the recycled non-woven fabric with virgin fabric were also evaluated.
+This work was focused on the recycling of dry carbon fiber scrap, which can proceed from part production by infusion technologies (e.g. RTM) or from pyrolysis of end of life composite part. The approach was to obtain a non-woven mat from the dry fiber scrap, following a mechanical process, which was, then, fully characterized to identify potential applications in aeronautical field. Different approaches of hybridization of the recycled non-woven mat with virgin carbon fiber fabric were also evaluated.
-<br/>
+<br/>'''Español:'''
 ==1. Introduction and scope==
@@ Line 32: / Line 40: @@
 Composite parts production techniques based on dry carbon fiber textiles and liquid resin, e.g. RTM (resin transfer molding) or LRI (liquid resin infusion), have been considered traditionally as prone to produce high scrap quantity, due to the use of wide material rolls instead of ATL (automatic tape laying) rolls or AFP (automated fiber placement) spools. However, the generated material scrap during production is also easier to recycle, since there is not or very low resin content, which can simplify the recycling by just needing a suitable textile or dry fiber material production process that can be fed with this scrap type. Thus, there are already commercial alternatives, such as recycled carbon fiber non-woven materials.
-The main motivation of this project was to evaluate a commercially available solution, non-woven mats, to recycle aeronautical dry carbon fiber scrap for aeronautical or non-aeronautical applications. These materials have a random short fiber orientation leading to final composites with poor fiber volume content and, then, low performance versus the state of art continuous and oriented carbon fiber aeronautical composites.
+The main motivation of this work was to evaluate a commercially available solution, non-woven mats, to recycle aeronautical dry carbon fiber scrap for aeronautical or non-aeronautical applications. These materials have a random short fiber orientation leading to final composites with poor fiber volume content and, then, low performance versus the state of art continuous and oriented carbon fiber aeronautical composites.
-−
-The project was focused on the production, study and evaluation of a recycled non-woven mat from dry carbon fiber fabric scrap, which is generated during the RTM production of aeronautical composite parts. The production of this non-woven mat was performed by an external company, STFI. Then, RTM process with standard aeronautical liquid resin was used to obtain composites with a carbon fiber volume content, and then mechanical properties, as high as possible. The produced flat composite panels were, then, characterized from mechanical point of view. Additionally, in order to reach higher mechanical performance, above all in terms of impact resistance, hybrid composite panels combining the recycled non-woven mat and a standard dry carbon fiber fabric were produced and characterized.
-This project has been performed by FIDAMC in collaboration Airbus, and was funded by the CDTI, as part of the national funding program MISIONES (call 2021) – OPTIMUS project – WP4.
+The main focus was the production, study and evaluation of a recycled non-woven mat from dry carbon fiber fabric scrap, which is generated during the RTM production of aeronautical composite parts. The production of this non-woven mat was performed by an external company, STFI. Then, RTM process with standard aeronautical liquid resin was used to obtain composites with a carbon fiber volume content, and then mechanical properties, as high as possible. The produced flat composite panels were, then, characterized from mechanical point of view. Additionally, in order to reach higher mechanical performance, above all in terms of impact resistance, hybrid composite panels combining the recycled non-woven mat and a standard dry carbon fiber fabric were produced and characterized.
 ==2. Recycled carbon fiber non-woven mat production ==
-State of Art recycled carbon materials can be obtained from dry carbon fiber material scrap or recovered carbon fibers from composites after resin removal processes (e.g. pyrolysis, solvolysis…) [1]. Among these options, the solution selected in this project was the production of a short carbon fiber non-woven mat [2] by an external partner, STFI (Saxon Textile Research Institute e.V., Germany) [3], which is a research institute with the capabilities to produce carbon fiber non-woven mat following the requirements of this project.
+State of Art recycled carbon materials can be obtained from dry carbon fiber material scrap or recovered carbon fibers from composites after resin removal processes (e.g. pyrolysis, solvolysis…) [1]. Among these options, the solution selected was the production of a short carbon fiber non-woven mat [2] by an external partner, STFI (Saxon Textile Research Institute e.V., Germany) [3], which is a research institute with the capabilities to produce carbon fiber non-woven mat following the requirements of this activity.
-The scrap source to produce the non-woven mat were expired virgin rolls of reference carbon fiber fabric (5HS), with epoxy binder and 370 gsm nominal areal weight, used in the RTM production of aeronautical composite parts. Production carbon fabric wastes were not used in this project, since this would impact in the schedule, due to the time needed to generate and compile the material scrap.
+The scrap source to produce the non-woven mat were expired virgin rolls of reference carbon fiber fabric (5HS), with epoxy binder and 370 gsm nominal areal weight, used in the RTM production of aeronautical composite parts. Production carbon fabric wastes were not used in this work, since this would impact in the schedule, due to the time needed to generate and compile the material scrap.
 A standard mechanical process to produce non-woven mats was used, which includes following steps: cutting or shredding to homogenize the feeding material, carding to align the carbon fiber and get a thin mat, cross-lapping where the roll overlaps until the needed fiber weight is achieved, and, finally, needle punching to compact the plies and get the final carbon fiber non-woven mats. It is important to highlight that, taking into account the non-woven mat production process, as it can be seen in <span id='cite-_Ref134529298'></span>[[#_Ref134529298|Figure 1]], the final material has some short carbon fiber orientation, which is almost transversal to the material roll production direction.
@@ Line 266: / Line 272: @@
 ==6. Acknowledgement==
-<span id='_GoBack'></span>The OPTIMUS project has been 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.
+<span id='_GoBack'></span>The work included in this article has been done inside the OPTIMUS project, which has been 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.
 ==7. References==

@@ Line 266: / Line 266: @@
 ==6. Acknowledgement==
-<span id='_GoBack'></span>The OPTIMUS project has been 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, Technical and Innovation Research 2021-2023.
+<span id='_GoBack'></span>The OPTIMUS project has been 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.
 ==7. References==

@@ Line 6: / Line 6: @@
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-'''A. Calero'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', T. Blanco'''<span style="text-align: center; font-size: 75%;">'''<sup>2</sup>'''</span>''', J. Sistach<sup>1</sup>, M. Ordóñez'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', S. Delgado'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', B. López'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span></div>
+'''A. Calero'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', T. Blanco'''<span style="text-align: center; font-size: 75%;">'''<sup>2</sup>'''</span>''', J. Sistach<sup>1</sup>, M. Ordóñez'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', S. Delgado'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''', B. López'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>, '''</span>'''R. Contento'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''','''<span style="text-align: center; font-size: 75%;">''' '''</span>'''M. R. Martínez'''<span style="text-align: center; font-size: 75%;">'''<sup>1</sup>'''</span>''' '''</div>
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
@@ Line 237: / Line 237: @@
   [[Image:Review_112957926513-image11-c.png|600px]] </div>
-<span id='_Ref134694805'></span><div id="_GoBack" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
+<div id="_Ref134694805" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 Figure 8: Mechanical test results – hybrid configurations / liquid epoxy 180 ºC curing vs. reference carbon fiber 5HS fabric / liquid epoxy 180 ºC curing requirements (AIMS 05-04-009 [10])</div>
@@ Line 264: / Line 264: @@
 Finally, the production and evaluation of a recycled fabric obtained from dry carbon fiber production scrap will be also investigated, as a suitable option to obtain better mechanical properties, following the same development path, including recycled carbon fiber yarn and fabric development and production in collaboration with a textile company, RTM composite panels manufacturing and characterization campaign. The hybridization of this recycled fabric with the recycled non-woven mat can also be considered to maximize the content of recycled carbon fiber content in final applications.
-==6. References==
+==6. Acknowledgement==
 {| style="width: 100%;"

@@ Line 232: / Line 232: @@
 Figure 7: CAI results – hybrid configurations / liquid epoxy 180 ºC curing vs. reference carbon fiber 5HS fabric / liquid epoxy 180 ºC curing requirement <span style="text-align: center; font-size: 75%;">(</span>AIMS 05-04-009 [10])</div>
-<span id='_GoBack'></span>The rest of the hybrid configuration laminate mechanical test results (average values) are shown versus the reference material requirements in the graph represented in <span id='cite-_Ref134694805'></span>[[#_Ref134694805|Figure 8]].
+The rest of the hybrid configuration laminate mechanical test results (average values) are shown versus the reference material requirements in the graph represented in <span id='cite-_Ref134694805'></span>[[#_Ref134694805|Figure 8]].
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
   [[Image:Review_112957926513-image11-c.png|600px]] </div>
-<div id="_Ref134694805" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
+<span id='_Ref134694805'></span><div id="_GoBack" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 Figure 8: Mechanical test results – hybrid configurations / liquid epoxy 180 ºC curing vs. reference carbon fiber 5HS fabric / liquid epoxy 180 ºC curing requirements (AIMS 05-04-009 [10])</div>

← Older revision	Revision as of 12:05, 5 December 2023
(No difference)

@@ Line 87: / Line 87: @@
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Figure 2: Micrographs – first panels produced with carbon fiber non-woven mat (areal weight: 300 gsm), a) panel 15 plies – Sample 1, b) panel 13 plies – Sample 1</div>
+Figure 2: Micrographs – first composite panels produced with carbon fiber non-woven mat (areal weight: 300 gsm), a) panel 15 plies – Sample 1, b) panel 13 plies – Sample 1</div>
 {| style="width: 100%;margin: 1em auto 0.1em auto;border-collapse: collapse;"
@@ Line 135: / Line 135: @@
 <div id="_Ref134693642" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Table 1: Fiber (f), resin (r) & void (o) contents (weight and/or volume) – first panels produced with carbon fiber non-woven mat (areal weight: 300 gsm). Avg.: average, Std.: standard deviation</div>
+Table 1: Fiber (f), resin (r) & void (o) contents (weight and volume) – first composite panels produced with carbon fiber non-woven mat (areal weight: 300 gsm). Avg.: average, Std.: standard deviation</div>
 After these preliminary trials to set up the production process, panels were produced with the recycled non-woven mat from expired virgin dry carbon fabric rolls. Among the 3 available carbon fiber non-woven mats with different areal weights, the heaviest one was selected (100 – 130 gsm areal weight), due to lower areal weight tolerance, in order to reduce the panel thickness deviations, as well as higher material consistency. In any case, the cutting process of this material was still more difficult than in case of standard aeronautical carbon fiber textiles.
@@ Line 147: / Line 147: @@
 <div id="_Ref134530492" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Figure 3: Panels produced with recycled carbon fiber non-woven mat for the characterization campaign</div>
+Figure 3: Composite panels produced with recycled carbon fiber non-woven mat (areal weight: 100-130 gsm) for the characterization campaign</div>
 ===3.2. Hybrid configurations===
@@ Line 182: / Line 182: @@
 <div id="_Ref134691523" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Table 2: Panel hybrid configurations</div>
+Table 2: Composite panel hybrid configurations - recycled carbon fiber non-woven mat and virgin carbon fiber 5HS fabric</div>
 ==4. Composite panels characterization==
@@ Line 198: / Line 198: @@
 Figure 4: Mechanical test results - recycled carbon fiber non-woven mat / liquid epoxy 180 ºC curing vs reference carbon fiber 5HS fabric / liquid epoxy 180 ºC curing requirements (AIMS 05-04-009 [10])</div>
-<span id='_GoBack'></span>Additionally, impact tests were carried out, which showed that the composite material produced with recycled carbon fiber non-woven material and standard RTM epoxy resin is too brittle. Then, the specimens were not able to withstand very low energy impact levels of 10 Joules, producing local surface damages or cracks in the specimen backside, while as the energy increased up to 50 Joules a catastrophic specimen failure occurred, as it can be observed in <span id='cite-_Ref134532075'></span>[[#_Ref134532075|Figure 5]]. This poor impact resistance behavior is not acceptable for aeronautical applications, then, it was decided not to proceed with the compression after impact (CAI) test.
+Additionally, impact tests were carried out, which showed that the composite material produced with recycled carbon fiber non-woven material and standard RTM epoxy resin is too brittle. Then, the specimens were not able to withstand very low energy impact levels of 10 Joules, producing local surface damages or cracks in the specimen backside, while as the energy increased up to 50 Joules a catastrophic specimen failure occurred, as it can be observed in <span id='cite-_Ref134532075'></span>[[#_Ref134532075|Figure 5]]. This poor impact resistance behavior is not acceptable for aeronautical applications, then, it was decided not to proceed with the compression after impact (CAI) test.
 {| style="width: 100%;border-collapse: collapse;"
@@ Line 218: / Line 218: @@
 The three flat panels produced with different hybrid configurations (2 blocks, sandwich and interleave) were characterized following the same testing program as in case laminates made of pure recycled carbon fiber non-woven mat. However, due to the unacceptable impact resistance results obtained with this non-woven material, the characterization campaign of the hybrid laminates was started by the impact tests, to evaluate if these hybrid configurations could overcome this issue.
-Since the three hybrid configurations showed better impact resistance behavior, obtaining an impact damage depth of 0.6 - 0.8 mm in case of 30 Joules impact, and a good progression and correlation between impact energy and damage size, in line with reference continuous carbon fiber 5HS fabric RTM composite impact behavior (impact energy: 30 Joules, indentation: 0.54 mm), it was decided to carry out the compression after impact tests. Impacted specimens with sandwich hybrid configuration as example are included (<span id='cite-_Ref134694570'></span>[[#_Ref134694570|Figure 6]]) and the results of CAI test (AITM 1-0010 [9]) obtained for the different hybrid configurations versus the average requirement for the reference material carbon fiber 5HS fabric 370 gsm / liquid epoxy resin 180 ºC curing (AIMS 05-04-009 [10]) are compiled in <span id='cite-_Ref135899646'></span>[[#_Ref135899646|Figure 7]].
+<span id='_GoBack'></span>Since the three hybrid configurations showed better impact resistance behavior, obtaining an impact damage depth of 0.6 - 0.8 mm in case of 30 Joules impact, and a good progression and correlation between impact energy and damage size, in line with reference continuous carbon fiber 5HS fabric RTM composite impact behavior (impact energy: 30 Joules, indentation: 0.54 mm), it was decided to carry out the compression after impact tests. Impacted specimens with sandwich hybrid configuration as example are included (<span id='cite-_Ref134694570'></span>[[#_Ref134694570|Figure 6]]) and the results of CAI test (AITM 1-0010 [9]) obtained for the different hybrid configurations versus the average requirement for the reference carbon fiber 5HS fabric 370 gsm / liquid epoxy resin 180 ºC curing (AIMS 05-04-009 [10]) are compiled in <span id='cite-_Ref135899646'></span>[[#_Ref135899646|Figure 7]].
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
@@ Line 224: / Line 224: @@
 <span id='_Ref134694570'></span><div id="_Ref134694646" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-Figure 6: Impacted specimens with different energies – panel with sandwich hybrid configuration / liquid epoxy resin 180 ºC curing</div>
+Figure 6: Impacted specimens with different energies – composite panel with sandwich hybrid configuration / liquid epoxy 180 ºC curing</div>
 <div id="_Ref135899646" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
@@ Line 246: / Line 246: @@
 * Recycled carbon fiber non-woven materials with low areal weight (100-130 gsm) and good consistency have been produced by STFI from conventional expired RTM carbon fiber fabric (5HS) with epoxy binder (370 gsm areal weight).
-* Composite panels with recycled carbon fiber non-woven mat and standard liquid epoxy resin 180 ºC curing class with good quality have been manufactured by RTM, although specific NDI needs to be developed, since ultrasonic inspection in terms of traditional quality control of CFRP is not applicable for this type of material. Fiber volume contents of 24-28 % were obtained, versus initial and typical lower values for this material type.
+* Composite panels with recycled carbon fiber non-woven mat and standard liquid epoxy resin 180 ºC curing class with good quality have been manufactured by RTM, although specific NDI needs to be developed, since ultrasonic inspection in terms of traditional quality control of CFRP is not applicable for this type of material. Fiber volume contents of 23-24 % were obtained, versus initial and typical lower values for this material type.
-* Mechanical characterization results of composites vs. requirements for continuous carbon fiber 5HS fabric 370 gsm / liquid epoxy 180 ºC curing (AIMS 05-04-009 [10]): tensile strength of 19-27 %, tensile modulus of 22-36 %, compression strength of 38-54 %, compression modulus of 20-31 % and OHC strength of 63%.
+* Mechanical characterization results of composites vs. requirements for continuous carbon fiber 5HS fabric 370 gsm / liquid epoxy 180 ºC curing (AIMS 05-04-009 [10]): tensile strength of 19-27 %, tensile modulus of 22-36 %, compression strength of 38-54 %, compression modulus of 20-31 % and OHC strength of 63 %.
 * Impact tests performed show that the composite material produced with recycled non-woven mat is too brittle, being a showstopper for the aeronautical application of this recycled material solution.