An electromagnetic shielding composite material for lightning protection and its preparation method

Abstract

The present invention discloses an electromagnetic shielding composite material for lightning protection and a preparation method thereof. The electromagnetic shielding composite material for lightning protection includes at least one perforated carbon nanotube film layer and at least one carbon fiber layer which are alternately stacked in sequence, and a plurality of hole structures penetrating along the thickness direction of the perforated carbon nanotube film layer are arranged on the perforated carbon nanotube film layer. By preparing the perforated carbon nanotube film layer and arranging the perforated carbon nanotube film layer in an intercalated manner in the carbon fiber resin, the present invention simultaneously enhances the structural strength, conductivity and resin toughness in the thickness direction. The obtained perforated carbon nanotube film layer has strong interfacial bonding force and does not affect the conductivity and shielding performance. The intercalation method brings excellent mechanical and electrical properties and lightning protection performance to the carbon-based composite material for lightning protection, and a laminated composite material with light weight, high strength, high conductivity and high shielding efficiency is obtained. At the same time, it has a good enhancement effect on the mechanical properties of the composite material.

Description

Technical Field

[0001] The present invention relates to an electromagnetic shielding composite material, specifically to a lightning protection electromagnetic shielding composite material and a preparation method thereof, belonging to the technical field of electromagnetic shielding materials science. Background Art

[0002] Due to its high specific strength, high specific stiffness, low density, and easy processing, carbon fiber reinforced resin-based laminated composites are widely used in aerospace and aircraft skins. However, compared with metal-based materials, resin-based composites are composed of reinforcing fibers and polymers, and their electrical conductivity is generally poor, which is relatively limited in the fields of lightning protection and electromagnetic shielding. When an aircraft is struck by lightning, the lightning current will generate huge Joule heat in the area near the lightning attachment point, resulting in a high temperature of 3000 - 30000 °C on the surface of the composite material, causing electrical damage or even ablation of the composite material. At the same time, the shielding effectiveness of pure resin-based carbon fiber plates is generally about 30 dB, and the external magnetic field easily interferes with the components inside the cabin. Therefore, it is necessary to improve the lightning protection and electromagnetic shielding performance of the composite material through interface regulation.

[0003] As an important one-dimensional carbon nanomaterial, carbon nanotube (CNT) materials have a variety of excellent properties. In particular, their excellent electrical conductivity makes them one of the important candidates for raw materials against lightning. Currently, the most common method for lightning protection is to composite a conductive layer on the surface of the composite material. For example, the reference patent CN103552296A proposes a lightning protection conductive layer filled with carbon nanotube powder in a metal network. The reference patent CN102001448A relates to a lightning protection surface film composed of a substrate and carbon nanotubes grown on its surface. There is also a moisture-resistant and heat-resistant electromagnetic shielding film of a conductive composite carbon nanotube film proposed in CN110337234A. Up to now, by dispersing carbon nanotube powder and composite conductive substances in the form of a film to be composite with the carbon fiber matrix to obtain carbon nanotube resin-based composites, these works do not consider the mechanical properties of the composite material after composite, and will cause delamination and affect the bonding with the resin. If the resin under the conductive layer evaporates, the accumulated pressure will cause greater damage. At the same time, the preparation processes of these materials are complex, and it is usually difficult to have composite properties such as high strength, high conductivity, and high shielding effectiveness at the same time.

[0004] Specifically, the combination of carbon nanotubes in the form of powder with the surface conductive layer in the prior art is mainly reflected in: the carbon nanotube conductive network is discontinuous and uneven, the transfer efficiency is low, the conductivity is insufficient, and the composite with the surface conductive layer generally uses a metal layer matrix. However, due to the high density of the metal, generally, weaving or porous compression methods are used, but the local double-layer thickness and non-uniform thickness, and the grid also has a high resistivity at the intersection points.

[0005] Currently, the anti-lightning strike shielding layer methods mostly studied are preparing composite materials with metal foils, metal coatings or metal braided meshes. The combination of metal foils and resin is poor. After being compounded with the carbon fiber resin matrix, delamination will occur. After lightning strikes, the resin under the metal foil evaporates, and the accumulated pressure will cause greater damage. Metal coatings have similar disadvantages to foils. To increase the conductivity, the coating thickness needs to be increased. When the thickness reaches a certain level, the coating is prone to cracking, and the intercalation method affects the binding property with the resin, resulting in delamination. The resin binding property and anti-lightning strike performance of metal braided meshes are excellent, but due to the large holes, the shielding effectiveness is poor within a certain frequency band. Therefore, it is still difficult to improve their comprehensive performance. Summary of the Invention

[0006] The main object of the present invention is to provide an electromagnetic shielding composite material for lightning protection and its preparation method to overcome the deficiencies in the prior art.

[0007] To achieve the foregoing invention object, the technical solutions adopted by the present invention include:

[0008] An embodiment of the present invention provides an electromagnetic shielding composite material for lightning protection, which includes at least one perforated carbon nanotube film layer and at least one carbon fiber layer that are alternately stacked in sequence. A plurality of hole structures penetrating along the thickness direction of the perforated carbon nanotube film layer are provided on the perforated carbon nanotube film layer.

[0009] Further, the electromagnetic shielding composite material for lightning protection is formed by intercalating the perforated carbon nanotube film layer between at least two carbon fiber layers.

[0010] Correspondingly, an embodiment of the present invention also provides a preparation method of the electromagnetic shielding composite material for lightning protection, which includes:

[0011] Providing a carbon nanotube film layer, and perforating a plurality of through hole structures in the thickness direction of the carbon nanotube film layer to form a perforated carbon nanotube film layer;

[0012] Intercalating at least one layer of the perforated carbon nanotube film layer between at least two carbon fiber layers, and alternately stacking them in sequence, and finally forming and curing to obtain the electromagnetic shielding composite material for lightning protection.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] The present invention realizes the simultaneous enhancement of the structural strength, conductivity, and resin toughness in the thickness direction by preparing a perforated carbon nanotube film layer and arranging the perforated carbon nanotube film layer in an intercalated manner in the carbon fiber resin. The obtained perforated carbon nanotube film layer has strong interfacial bonding force and does not affect the conductivity and shielding performance. The intercalation method brings excellent mechanical and electrical properties and lightning strike resistance to the lightning strike-resistant carbon-based composite material, resulting in a laminated composite material with light weight, high strength, high conductivity, and high shielding efficiency, and at the same time having a good strengthening effect on the mechanical properties of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic structural diagram of an electromagnetic shielding composite material for lightning strike protection in a typical embodiment of the present invention;

[0017] Figure 2 It is a shielding performance diagram of carbon nanotube films with different perforation spacings in Example 1 of the present invention;

[0018] Figure 3 It is an interfacial CT test image of the material surface after lightning strike in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention;

[0019] Figure 4 It is an electromagnetic shielding efficiency diagram of a carbon nanotube / carbon fiber composite board in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention;

[0020] Figure 5 It is a mechanical property diagram of the obtained perforated carbon nanotube / carbon fiber composite board in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to better solve the problem of weak performance between the conductive layer and the resin layer of the existing lightning strike-resistant carbon fiber shielding composite material, improve the conductivity of the film-like conductive layer, and reduce the density of the metal-like conductive layer, mainly to improve the specific conductivity of the conductive layer. After a large amount of research, the inventors of this case have proposed the technical solution of the present invention. It mainly proposes a method for enhancing the interlayer performance of a carbon fiber composite material, which is manufactured by a perforated carbon nanotube film, and through the intercalated arrangement of the perforated carbon nanotube film in the carbon fiber resin, thereby realizing the simultaneous enhancement of the structural strength, conductivity, and resin toughness in the thickness direction.

[0022] The technical solution, its implementation process, principles, etc. will be further explained below. The following describes the preferred implementation manners of the embodiments of the present invention. It should be noted that for those of ordinary skill in the art, several improvements can be made without departing from the principles of the embodiments of the present invention, and these improvements are also regarded as the protection scope of the embodiments of the present invention.

[0023] Please refer to Figure 1 As shown, a lightning protection electromagnetic shielding composite material provided by an aspect of the embodiments of the present invention includes at least one perforated carbon nanotube film layer and at least one carbon fiber layer that are alternately laminated in sequence. A plurality of hole structures penetrating in the thickness direction of the perforated carbon nanotube film layer are provided on the perforated carbon nanotube film layer.

[0024] In some embodiments, the damage depth of the lightning protection electromagnetic shielding composite material after being struck by lightning can reach (not exceed) 0.6 mm at the lowest, the shielding performance is as high as more than 97 dB, and the bending strength is as high as 900 - 1000 MPa.

[0025] In some embodiments, the size of the hole structures provided on the perforated carbon nanotube film layer should be between 1 - 5 mm, and the hole spacing is 1 - 10 mm.

[0026] In some embodiments, the lightning protection electromagnetic shielding composite material is formed by intercalating the perforated carbon nanotube film layer between at least two carbon fiber layers, and the number of intercalated layers is 1 - 32 layers.

[0027] In some embodiments, the thickness of the perforated carbon nanotube film layer used for intercalation should be greater than 10 μm.

[0028] Further, the perforated carbon nanotube film layer includes a multi-walled carbon nanotube film, but is not limited thereto.

[0029] In some embodiments, the shapes of the hole structures provided on the perforated carbon nanotube film layer include at least any one of square, triangular, circular, polygonal, etc., but are not limited thereto.

[0030] In some embodiments, the lightning protection electromagnetic shielding composite material further includes a metal layer. The metal layer is provided on the perforated carbon nanotube film layer and is provided with through holes corresponding to the hole structures on the perforated carbon nanotube film layer. Among them, the material of the metal layer includes at least any one of copper, silver, gold, etc., but is not limited thereto. Specifically, other metals that have good electrical conductivity with the carbon nanotube film can be introduced in the present invention, and the lightning protection performance of the composite material can also be improved, or a conductive layer of metal plating, such as copper, silver, gold, etc. For example, a Cu-carbon nanotube thin film can be used as the conductive layer to obtain a layered carbon-carbon lightning protection composite material, and a highly conductive copper layer is introduced.

[0031] Further, the thickness of the metal layer is at the micron level, and the metal layer is deposited on the carbon nanotube film with a micron thickness.

[0032] In some embodiments, the carbon fiber layer includes at least any one of carbon fiber fabric and carbon fiber prepreg.

[0033] Further, the carbon fiber fabric is woven from commercially available carbon fibers, and the weaving method may include any one or a combination of two or more of unidirectional, plain, twill, satin, etc., but is not limited thereto.

[0034] Further, the carbon fiber prepreg is obtained by compounding a carbon fiber fabric and a matrix resin, and the matrix resin may include any one or a combination of two or more of epoxy resin, benzoxazine resin, bismaleimide resin, polyimide resin, etc., but is not limited thereto.

[0035] Further, the thickness of the carbon fiber layer is 0.02 mm to 0.25 mm.

[0036] Another aspect of the embodiments of the present invention also provides a method for preparing the electromagnetic shielding composite material for lightning protection, which includes:

[0037] Providing a carbon nanotube film layer, and forming a plurality of through-hole structures penetrating in the thickness direction of the carbon nanotube film layer to form a perforated carbon nanotube film layer;

[0038] Inserting at least one layer of the perforated carbon nanotube film layer between at least two carbon fiber layers, and alternately stacking them in sequence, and finally forming and curing to obtain the electromagnetic shielding composite material for lightning protection.

[0039] The present invention is manufactured by a perforated carbon nanotube film, and through the intercalation arrangement of the perforated carbon nanotube film in the carbon fiber resin, the structural strength, conductivity, and resin toughness in the thickness direction are simultaneously enhanced.

[0040] In some embodiments, the preparation method includes: preparing the perforated carbon nanotube film layer by laser drilling. The present invention can significantly improve the resin wettability, improve the delamination phenomenon between carbon fibers, and improve the interlayer mechanical properties through the perforation method.

[0041] Further, the present invention uses a single-layer and multi-layer carbon nanotube film as a conductive layer to cover the surface of the lightning protection composite material, and further improves the lightning protection performance through the intercalation method.

[0042] Further, the carbon nanotube film layer is obtained by floating catalyst chemical vapor deposition.

[0043] In a more preferred embodiment, the preparation method includes: first, a metal layer is disposed on the carbon nanotube film layer, and then the perforated carbon nanotube film layer is prepared by laser drilling.

[0044] In some embodiments, the forming and curing process may include at least any one of autoclave molding, RTM, compression molding, vacuum assisted or vacuum bag molding, etc., but is not limited thereto. The specific operation is carried out according to the molding conditions of the matrix resin.

[0045] Among them, in some more specific embodiments, the preparation method of the electromagnetic shielding composite material for lightning protection (which can also be called the "perforation-intercalation method of the electromagnetic shielding composite material for lightning protection") specifically includes:

[0046] The highly conductive multi-walled carbon nanotube film prepared by the floating catalyst chemical vapor deposition method is prepared into a perforated carbon nanotube film layer by laser drilling, and it is intercalated between the carbon fiber fabric or carbon fiber prepreg layers, and then the final composite material is obtained according to the preparation process and curing process of the composite material. The perforation size is between 1 and 5 mm, and the number of intercalated layers is 1 to 32 layers.

[0047] The finished product prepared by this preparation method is a laminated carbon fiber composite material product containing one or more layers of compressed perforated carbon nanotube composite structures.

[0048] After adopting the above technical solution, the present invention physically modifies and drills the carbon nanotubes to obtain a perforated continuous carbon nanotube composite structure, and then modifies the interface between the continuous carbon fiber laminated composite materials (carbon nanotube modified resin to improve the interface structure). Through the conductive connectivity and toughness structure of the carbon-based material structure, the conductivity and toughness of the laminated composite material are improved, and a laminated composite material with excellent lightning resistance, light weight, high strength, high conductivity, and high shielding efficiency is obtained, so that the composite structure has good conductivity, and at the same time has a good strengthening effect on the mechanical properties of the composite material.

[0049] The interface bonding force of the perforated carbon nanotube film layer prepared by the present invention is strong and does not affect the conductivity and shielding performance. The excellent mechanical and electrical properties brought to the electromagnetic shielding composite material for lightning protection by the intercalation method are mainly reflected in: 1) the excellent conductivity of the carbon nanotube film; 2) the thickness of the carbon nanotube film layer affects the wettability of the resin, and the perforation improves the interface structure but does not affect the conductivity, which has a positive improvement effect on the shielding efficiency of the composite material; 3) the perforated carbon nanotube film layer has a better lightning protection effect by the intercalation method than covering on the surface, and the stable carbon-carbon interface structure also greatly improves the current-carrying capacity of lightning strikes; 4) this composite material also has excellent shielding efficiency.

[0050] The technical solutions of the present invention will be further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. The implementation conditions adopted in the following embodiments can be further adjusted according to actual needs, and the implementation conditions not specified are usually those in conventional experiments.

[0051] Example 1

[0052] A carbon nanotube film with a thickness of 12 μm is obtained by the floating catalyst chemical vapor deposition method, and a perforated carbon nanotube film layer is prepared by laser drilling. The hole size is set to be The interval between holes is 1 mm, and the SE of the perforated carbon nanotube film with different hole spacings (1 - 10 mm) is tested T 、SE A and SE R . The shielding performance results are as shown in Figure 2 . It is found that when the hole interval is 1 mm, the electromagnetic shielding effectiveness of the carbon nanotube film is the largest.

[0053] Using the vacuum bag assisted molding process, every 4 layers of the perforated carbon nanotube film are laminated on the orthogonally stacked carbon fiber unidirectional prepreg, and cured in an oven at 130 °C for 1.5 h to obtain a perforated carbon nanotube / carbon fiber composite board with a thickness of 4.5 mm. Through the three-point bending test, it is proved that the intercalated structure still has excellent mechanical properties, and the results are as shown in Figure 5 .

[0054] The inventors of this case also tested other properties of the electromagnetic shielding composite material for lightning protection obtained in the foregoing embodiments. For example, the electromagnetic shielding effectiveness ( Figure 4 ) and the lightning strike resistance ( Figure 3 ) of the perforated carbon nanotube / carbon fiber composite board were tested. The research results show that the electromagnetic shielding effectiveness of the perforated carbon nanotube / carbon fiber composite board is higher than that of the pure carbon fiber composite board. After CT detection, it is found that the damage depth after lightning strike is reduced, with a minimum of 0.59 mm.

[0055] Of course, referring to the steps of Example 1, the punching of the carbon nanotube film can also be other sizes, which can be between 1 and 5 mm. In addition, the inventors of this case can also intercalate other numbers of layers of perforated carbon nanotube film layers between the carbon fiber layers. For example, the number of intercalated layers can be 1 - 32 layers. Among them, the carbon fiber unidirectional prepreg can be obtained by compounding carbon fiber fabric with matrix resins such as epoxy resin, benzoxazine resin, bismaleimide resin, and polyimide resin, and the carbon fiber unidirectional prepreg can also be replaced by carbon fiber fabric woven from carbon fibers.

[0056] Control Example 1

[0057] A carbon nanotube film with a thickness of 10 μm was obtained by floating catalyst chemical vapor deposition. Using a vacuum bag assisted molding process, every 4 layers of the carbon nanotube film were covered on an orthogonally stacked carbon fiber unidirectional prepreg, and cured at 130 °C for 1.5 h in an oven to obtain a carbon nanotube / carbon fiber composite board, and the thickness of the composite board was 4.5 mm.

[0058] The electromagnetic shielding effectiveness ( Figure 4 ) and lightning strike resistance ( Figure 3 ) of the carbon nanotube / carbon fiber composite board were tested. The research results show that the electromagnetic shielding effectiveness of the perforated carbon nanotube / carbon fiber composite board is higher than that of the carbon nanotube / carbon fiber composite board. After CT detection, it was found that the depth of damage after lightning strike was 0.79 mm.

[0059] Control Example 2

[0060] A carbon nanotube film with a thickness of 10 μm was obtained by floating catalyst chemical vapor deposition. A perforated carbon nanotube film layer was prepared by laser drilling. The hole size was set to The interval between holes was 1 mm.

[0061] Using a vacuum bag assisted molding process, a single-layer perforated carbon nanotube film was covered on an orthogonally stacked carbon fiber unidirectional prepreg, and cured at 130 °C for 1.5 h in an oven to obtain a perforated carbon nanotube / carbon fiber composite board, and the thickness of the composite board was 4.5 mm. The lightning strike resistance ( Figure 3 ) of the carbon nanotube / carbon fiber composite board was tested. The research results show that the depth of damage after lightning strike of the un-intercalated perforated carbon nanotube / carbon fiber composite board is 0.95 mm, which is higher than that of the intercalated perforated carbon nanotube / carbon fiber composite board.

[0062] Example 2

[0063] A carbon nanotube film with a thickness of 12 μm was obtained by floating catalyst chemical vapor deposition. A 500 nm copper layer was deposited on the perforated carbon nanotube film by physical vapor deposition to prepare a copper-plated carbon nanotube film. A perforated carbon nanotube film layer was prepared by laser drilling. The hole size was set to The interval between holes was 1 mm.

[0064] Using a vacuum bag assisted molding process, every 4 layers of the perforated copper-plated carbon nanotube film were covered on an orthogonally stacked carbon fiber unidirectional prepreg, and cured at 130 °C for 1.5 h in an oven to obtain a perforated carbon nanotube / carbon fiber composite board, and the thickness of the composite board was 4.5 mm. Through shielding performance testing, it was proved that the metal coating can improve the overall shielding effectiveness of the composite board, and the results are as Figure 4 shown.

[0065] In addition, with reference to the foregoing embodiments, the inventors of this case also conducted tests using other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0066] It should be understood that the above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. An electromagnetic shielding composite material for lightning protection, characterized in that, It includes at least one perforated carbon nanotube film layer and at least one carbon fiber layer that are alternately stacked in sequence. A plurality of hole structures penetrating in the thickness direction of the perforated carbon nanotube film layer are provided on the perforated carbon nanotube film layer; the size of the hole structures provided on the perforated carbon nanotube film layer is 1 - 5 mm, and the hole pitch is 1 - 10 mm.

2. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The damage depth of the electromagnetic shielding composite material for lightning protection after being struck by lightning does not exceed 0.6 mm, the shielding performance is above 97 dB, and the flexural strength is 900 - 1000 MPa.

3. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The electromagnetic shielding composite material for lightning protection is formed by intercalating the perforated carbon nanotube film layer between at least two carbon fiber layers, and the number of intercalated layers is 1 - 32 layers.

4. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The thickness of the perforated carbon nanotube film layer is greater than 10 μm.

5. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The perforated carbon nanotube film layer is a multi-walled carbon nanotube film.

6. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The shape of the hole structures provided on the perforated carbon nanotube film layer is selected from at least any one of square, triangular, circular, and polygonal.

7. The electromagnetic shielding composite material for lightning protection according to claim 1, characterized in that It further includes a metal layer. The metal layer is provided on the perforated carbon nanotube film layer and is provided with through holes corresponding to the hole structures on the perforated carbon nanotube film layer.

8. The electromagnetic shielding composite material for lightning protection according to claim 7, wherein: The material of the metal layer is selected from at least any one of copper, silver, and gold.

9. The electromagnetic shielding composite material for lightning protection according to claim 8, characterized in that: The thickness of the metal layer is at the micron level.

10. The electromagnetic shielding composite material for lightning protection according to claim 1, characterized in that: The carbon fiber layer is selected from at least any one of carbon fiber fabric and carbon fiber prepreg.

11. The electromagnetic shielding composite material for lightning protection according to claim 10, characterized in that: The carbon fiber fabric is obtained by weaving carbon fibers, and the weaving method is selected from any one or a combination of two or more of unidirectional, plain, twill, and satin.

12. The electromagnetic shielding composite material for lightning protection according to claim 10, wherein: The carbon fiber prepreg is obtained by compounding a carbon fiber fabric and a matrix resin.

13. The electromagnetic shielding composite material for lightning protection according to claim 12, characterized in that: The matrix resin is selected from any one or a combination of two or more of epoxy resin, benzoxazine resin, bismaleimide resin, and polyimide resin.

14. The electromagnetic shielding composite material for lightning protection according to claim 1, wherein: The thickness of the carbon fiber layer is 0.02 mm - 0.25 mm.

15. The preparation method of the electromagnetic shielding composite material for lightning protection according to any one of claims 1-14, characterized in that, It includes: Providing a carbon nanotube film layer, and perforating a plurality of through hole structures in the thickness direction of the carbon nanotube film layer to form a perforated carbon nanotube film layer; Intercalating at least one layer of the perforated carbon nanotube film layer between at least two carbon fiber layers, and alternately stacking them in sequence, and finally molding and curing to obtain the electromagnetic shielding composite material for lightning protection.

16. The preparation method according to claim 15, characterized in that: The carbon nanotube film layer is obtained by the floating catalyst chemical vapor deposition method.

17. The preparation method according to claim 15, wherein It includes: Preparing the perforated carbon nanotube film layer by laser drilling.

18. The preparation method according to claim 17, wherein It includes: First, setting a metal layer on the carbon nanotube film layer, and then preparing the perforated carbon nanotube film layer by laser drilling.

19. The preparation method according to claim 15, characterized in that: The process of molding and curing is selected from at least any one of autoclave molding, RTM, compression molding, vacuum assisted, and vacuum bag molding.

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