Airplane sealing structure and preparation method thereof

Abstract

The invention provides an airplane sealing structure and a preparation method thereof. The preparation method of the airplane sealing structure comprises the following steps: S1, preparing a carbon fiber skeleton, a modified raw rubber layer and conductive fiber cloth; wherein the preparation raw materials of the modified raw rubber layer comprise a rubber master batch and a conductive material; s2, first glue is arranged on the surface of at least one side of the carbon fiber framework, and second glue is arranged on the surface of at least one side of the conductive fiber cloth; superposing a modified raw rubber layer and conductive fiber cloth on the surface of at least one side of the carbon fiber skeleton to obtain an intermediate; and S3, the intermediate is subjected to vulcanization treatment, and the airplane sealing structure is obtained. The airplane sealing structure prepared by the method not only has the advantages of high structural strength, large deformation, high rebound resilience, good fatigue resistance and the like, but also has certain conductivity.

Description

Aircraft sealing structure and its preparation method Technical Field

[0001] This invention relates to the field of aircraft sealing structure manufacturing technology, and in particular to an aircraft sealing structure and its manufacturing method. Background Technology

[0002] The gap between the main wing surface and the movable wing surface of an aircraft can affect its flight performance. Furthermore, external moisture can enter the wing through this gap, corroding the internal connecting and transmission structures, thus impacting the wing's reliability and lifespan. Therefore, sealing structures are typically installed at the gap between the main wing surface and the movable wing surface. These sealing structures eliminate the gap, improve the smoothness of the wing surface, and prevent external moisture from entering the wing (the structure of the sealing structure can be found in patents such as CN207725605U). Because the aircraft wing surface deflects and bends during flight, the sealing structure needs to possess high strength and high rigidity to resist aerodynamic suction, as well as large deformation and high resilience to adapt to deflection / bending conditions.

[0003] Existing sealing structures generally use metal or composite material structures. However, due to the excessive rigidity of metal and composite material structures, they are difficult to meet the requirements for use under large deformation conditions. During deflection, excessive stress can easily cause excessive torque on the servo motor, affecting aerodynamic operability and aircraft safety.

[0004] To address the aforementioned issues, some existing sealing structures employ a composite structure of rubber and composite materials. However, this structure currently suffers from the following problems: In certain application scenarios, the sealing structure needs to possess a certain degree of conductivity to ensure its electrical continuity, allowing electromagnetic waves to smoothly transition across the sealing structure's surface and thus guaranteeing the continuity of electromagnetic waves traveling on the wing surface. However, since rubber materials are non-conductive, they cannot meet the conductivity requirements of the sealing structure, thereby failing to guarantee the continuity of electromagnetic waves traveling on the wing surface. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing an aircraft sealing structure. The aircraft sealing structure prepared by this method not only has the advantages of high structural strength, large deformation, high resilience and good fatigue resistance, but also has a certain degree of conductivity, which can realize the electrical continuity of the aircraft sealing structure.

[0006] This invention provides a method for preparing an aircraft sealing structure, comprising the following steps: S1: preparing a carbon fiber skeleton, a modified rubber raw rubber layer, and a conductive fiber cloth; wherein, the raw materials for preparing the modified rubber raw rubber layer include rubber masterbatch and conductive materials; S2: applying a first adhesive to at least one surface of the carbon fiber skeleton, and applying a second adhesive to at least one surface of the conductive fiber cloth; stacking the modified rubber raw rubber layer and the conductive fiber cloth on at least one surface of the carbon fiber skeleton, such that the modified rubber raw rubber layer is located on opposite sides of the conductive fiber cloth, or the modified rubber raw rubber layer... An adhesive layer is located between the carbon fiber skeleton and the conductive fiber cloth to obtain an intermediate body; wherein, the carbon fiber skeleton is pre-bonded to the modified rubber raw rubber layer by the first adhesive, and the conductive fiber cloth is pre-bonded to the modified rubber raw rubber layer by the second adhesive; S3: The intermediate body is subjected to vulcanization treatment to obtain an aircraft sealing structure, wherein the modified rubber raw rubber layer in the intermediate body forms a conductive rubber layer after vulcanization treatment; wherein, the vulcanization temperature of the intermediate body is 150℃~190℃, the vulcanization time is 10 minutes~60 minutes, and the vulcanization pressure is 15MPa~20MPa.

[0007] In one feasible embodiment, in step S1 above, the raw materials for preparing the modified rubber raw rubber layer further include a low-temperature resistant modifying material; the rubber masterbatch is methyl vinyl fumed silica gel, the low-temperature resistant modifying material includes low-phenyl silicone rubber, and the conductive material includes aluminum-plated fumed silica gel; wherein the mass of the low-phenyl silicone rubber is 15% to 25% of the mass of the methyl vinyl fumed silica gel, and the mass of the aluminum-plated fumed silica gel is 4% to 6% of the mass of the methyl vinyl fumed silica gel.

[0008] In one feasible manner, in step S1 above, the raw materials for preparing the modified rubber raw rubber layer further include a compatibilizer and a first crosslinking agent; wherein the mass of the compatibilizer is 0.5% to 1.5% of the mass of the methyl vinyl fumed silica gel, and the mass of the first crosslinking agent is 1.5% to 2.0% of the mass of the methyl vinyl fumed silica gel.

[0009] In one feasible embodiment, in step S1 above, the raw materials for preparing the modified rubber raw rubber layer further include a low-temperature resistant modifying material; the rubber masterbatch is hydrogenated nitrile butadiene rubber, the low-temperature resistant modifying material includes dioctyl adipate and hydrogenated nitrile butadiene liquid, and the conductive material includes aluminum-plated fumed silica; wherein the mass of dioctyl adipate is 1.5% to 2.5% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the hydrogenated nitrile butadiene liquid is 0.5% to 1.5% of the mass of the hydrogenated nitrile butadiene rubber, and the mass of the aluminum-plated fumed silica is 4% to 6% of the mass of the hydrogenated nitrile butadiene rubber.

[0010] In one feasible embodiment, in step S1 above, the raw materials for preparing the modified rubber raw rubber layer further include a reinforcing agent, an activator, an antioxidant, an accelerator, and a second crosslinking agent; wherein the mass of the reinforcing agent is 30% to 40% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the activator is 2.5% to 6.5% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the antioxidant is 1% to 2% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the accelerator is 0.5% to 1.5% of the mass of the hydrogenated nitrile butadiene rubber, and the mass of the second crosslinking agent is 3% to 5% of the mass of the hydrogenated nitrile butadiene rubber.

[0011] In one feasible manner, the preparation step of the carbon fiber skeleton in step S1 above includes: (1) pressing epoxy resin or bismaleimide resin to form a film, and placing the film on both sides of the carbon fiber fabric to obtain carbon fiber prepreg; (2) stacking multiple layers of the carbon fiber prepreg and vacuum-treating the multiple layers of the carbon fiber prepreg to obtain a carbon fiber composite; (3) placing the carbon fiber composite in a hot autoclave for curing to obtain the carbon fiber skeleton; wherein the curing temperature of the carbon fiber composite is 150℃~185℃, the curing time is 3 hours~7 hours, and the curing pressure is 0.3MPa~0.6MPa.

[0012] In one feasible approach, the preparation step of the conductive fiber cloth in step S1 above includes: setting a conductive material on the surface of the fiber filaments to obtain conductive fiber filaments, and then weaving the conductive fiber filaments into the conductive fiber cloth; or, setting a conductive material on the surface of the fiber cloth to obtain the conductive fiber cloth.

[0013] In one possible implementation, in step S2 above, the first adhesive is an epoxy resin adhesive, and the second adhesive is an isocyanate adhesive; the first adhesive is disposed on one side of the surface of the carbon fiber skeleton, and the modified rubber raw rubber layer and the conductive fiber cloth are superimposed on the surface of the carbon fiber skeleton on the side where the first adhesive is disposed; or, the first adhesive is disposed on the surfaces of opposite sides of the carbon fiber skeleton, and the modified rubber raw rubber layer and the conductive fiber cloth are superimposed on both opposite sides of the carbon fiber skeleton.

[0014] In one feasible manner, in step S3 above, after the intermediate is vulcanized, a primer layer and a wear-resistant coating are sequentially applied to the surface of at least one side of the intermediate.

[0015] The present invention also provides an aircraft sealing structure, which is manufactured using the aircraft sealing structure preparation method described above; the aircraft sealing structure includes a carbon fiber skeleton and a conductive rubber layer and a conductive fiber cloth disposed on at least one surface of the carbon fiber skeleton.

[0016] The method for preparing an aircraft sealing structure provided by this invention involves integrally vulcanizing a carbon fiber skeleton, a modified rubber layer, and a conductive fiber cloth to obtain the aircraft sealing structure. Because the aircraft sealing structure incorporates a carbon fiber skeleton, a conductive rubber layer, and a conductive fiber cloth, it possesses advantages such as high structural strength, large deformation, high resilience, and good fatigue resistance, meeting the requirements of not being damaged under long-term, large-angle bending conditions. Simultaneously, the presence of a first adhesive on the surface of the carbon fiber skeleton and a second adhesive on the surface of the conductive fiber cloth allows the first adhesive to bond the carbon fiber skeleton and the conductive rubber layer, and the second adhesive to bond the conductive fiber cloth and the conductive rubber layer. This improves the bonding force and strength among the three components, preventing delamination and thus enhancing the overall structural strength of the aircraft sealing structure.

[0017] Meanwhile, because conductive materials are added to the modified rubber raw rubber layer in the rubber masterbatch, the conductive rubber layer has a certain degree of conductivity, and the conductive fiber cloth also has a certain degree of conductivity, thus giving the aircraft sealing structure a certain degree of conductivity, realizing the electrical continuity of the aircraft sealing structure, and meeting the conductivity requirements of the aircraft sealing structure. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a cross-sectional schematic diagram of the aircraft sealing structure in an embodiment of the present invention.

[0020] Figure 2 is a cross-sectional schematic diagram of the aircraft sealing structure in another embodiment of the present invention.

[0021] Figure 3 is a cross-sectional schematic diagram of the aircraft sealing structure in another embodiment of the present invention.

[0022] Figure 4 is a cross-sectional schematic diagram of the aircraft sealing structure in another embodiment of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in further detail below. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. The terms "first," "second," "third," "fourth," etc. (if present) in the specification and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0024] As shown in Figure 1, this embodiment of the invention provides a method for preparing an aircraft sealing structure, including the following steps: S1: Preparing a carbon fiber skeleton 1, a modified rubber raw rubber layer, and a conductive fiber cloth 3; wherein, the raw materials for preparing the modified rubber raw rubber layer include rubber masterbatch and conductive materials, and the modified rubber raw rubber layer has a sheet-like structure (i.e., a layered structure); the conductive fiber cloth 3 is a fiber cloth with a certain conductivity; S2: Applying a first adhesive to at least one surface of the carbon fiber skeleton 1, and applying a second adhesive to at least one surface of the conductive fiber cloth 3; stacking the modified rubber raw rubber layer and the conductive fiber cloth 3 along the thickness direction on at least one surface of the carbon fiber skeleton 1, such that the modified rubber raw rubber layer is located on opposite sides of the conductive fiber cloth 3 (as shown in Figure 3 or Figure 4, or...). A modified rubber raw rubber layer is located between the carbon fiber skeleton 1 and the conductive fiber cloth 3 to obtain an intermediate body; wherein, the carbon fiber skeleton 1 is pre-bonded to the modified rubber raw rubber layer by a first adhesive, and the conductive fiber cloth 3 is pre-bonded to the modified rubber raw rubber layer by a second adhesive; S3: The intermediate body is subjected to vulcanization treatment to obtain the aircraft sealing structure 100; after vulcanization treatment, the modified rubber raw rubber layer in the intermediate body vulcanizes to form a conductive rubber layer 2, the first adhesive cures and firmly bonds the conductive rubber layer 2 to the carbon fiber skeleton 1, and the second adhesive cures and firmly bonds the conductive rubber layer 2 to the conductive fiber cloth 3, that is, the aircraft sealing structure 100 includes a carbon fiber skeleton 1 and a conductive rubber layer 2 and a conductive fiber cloth 3 disposed on at least one side surface of the carbon fiber skeleton 1. The vulcanization temperature of the intermediate body is 150℃~190℃, the vulcanization time is 10 minutes~60 minutes, and the vulcanization pressure is 15MPa~20MPa.

[0025] In step S2 above, as shown in Figures 1 and 2, the modified rubber raw rubber layer, conductive fiber cloth 3, and modified rubber raw rubber layer can be stacked on at least one side of the carbon fiber skeleton 1 in the following order: modified rubber raw rubber layer - conductive fiber cloth 3 - modified rubber raw rubber layer. That is, two modified rubber raw rubber layers are stacked, with the conductive fiber cloth 3 sandwiched between the two modified rubber raw rubber layers (i.e., one modified rubber raw rubber layer is sandwiched between the carbon fiber skeleton 1 and the conductive fiber cloth 3, and the other modified rubber raw rubber layer is located on the side of the conductive fiber cloth 3 away from the carbon fiber skeleton 1). It is important to note that a second adhesive needs to be applied to both opposite surfaces of the conductive fiber cloth 3 to pre-bond the conductive fiber cloth 3 to the two modified rubber raw rubber layers via the second adhesive on both sides. After subsequent vulcanization, two conductive rubber layers 2 are obtained, with the conductive fiber cloth 3 sandwiched between the two conductive rubber layers 2 (i.e., one conductive rubber layer 2 is sandwiched between the carbon fiber skeleton 1 and the conductive fiber cloth 3, and the other conductive rubber layer 2 is located on the side of the conductive fiber cloth 3 away from the carbon fiber skeleton 1). This method is the preferred stacking method.

[0026] As shown in Figures 3 and 4, the modified rubber raw rubber layer and the conductive fiber cloth 3 can also be stacked on at least one side of the carbon fiber skeleton 1 in the order of modified rubber raw rubber layer and conductive fiber cloth 3. That is, a modified rubber raw rubber layer is stacked and sandwiched between the carbon fiber skeleton 1 and the conductive fiber cloth 3. At this time, the conductive fiber cloth 3 has a second adhesive on at least one side of the surface close to the modified rubber raw rubber layer (or the second adhesive can be applied to both sides) so that the conductive fiber cloth 3 is pre-bonded to the modified rubber raw rubber layer through the second adhesive. After subsequent vulcanization treatment, a conductive rubber layer 2 is obtained and sandwiched between the carbon fiber skeleton 1 and the conductive fiber cloth 3.

[0027] In step S3 above, the intermediate can be vulcanized in a vulcanizing machine (e.g., a flat vulcanizing machine). The vulcanization temperature of the intermediate can be 150℃, 160℃, 170℃, 180℃, 190℃, etc., or any combination of the above temperatures; the vulcanization time can be 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc., or any combination of the above times; the vulcanization pressure can be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, etc., or any combination of the above pressures.

[0028] The method for preparing the aircraft sealing structure provided in this invention involves integrally vulcanizing a carbon fiber skeleton 1, a modified rubber layer, and a conductive fiber cloth 3 to obtain the aircraft sealing structure 100. Because the aircraft sealing structure 100 incorporates the carbon fiber skeleton 1, the conductive rubber layer 2, and the conductive fiber cloth 3, it possesses advantages such as high structural strength, large deformation, high resilience, and good fatigue resistance, meeting the requirements of not being damaged under long-term, large-angle bending conditions. Simultaneously, the presence of a first adhesive on the surface of the carbon fiber skeleton 1 and a second adhesive on the surface of the conductive fiber cloth 3 allows the first adhesive to bond the carbon fiber skeleton 1 and the conductive rubber layer 2, and the second adhesive to bond the conductive fiber cloth 3 and the conductive rubber layer 2. This improves the bonding force and strength among the three components, preventing peeling and thus enhancing the overall structural strength of the aircraft sealing structure 100.

[0029] Meanwhile, since conductive materials are added to the modified rubber raw rubber layer in the rubber masterbatch, the conductive rubber layer 2 has a certain degree of conductivity, and the conductive fiber cloth 3 also has a certain degree of conductivity, thus making the aircraft sealing structure 100 have a certain degree of conductivity, realizing the electrical continuity of the aircraft sealing structure 100 and meeting the conductivity requirements of the aircraft sealing structure 100.

[0030] In one embodiment, the first adhesive is an epoxy resin adhesive, and the second adhesive is an isocyanate adhesive; of course, in other embodiments, the first and second adhesives can also be other types of adhesives. In step S2 above, the first adhesive is applied to the surface of the carbon fiber skeleton 1. Specifically, the carbon fiber skeleton 1 can be immersed in the first adhesive for a period of time (e.g., 5-20 minutes), during which time both sides of the carbon fiber skeleton 1 are coated with the first adhesive; alternatively, the first adhesive can be sprayed onto the surface of the carbon fiber skeleton 1, thereby adhering the first adhesive to the surface of the carbon fiber skeleton 1. In step S2 above, the second adhesive is applied to the surface of the conductive fiber cloth 3. Specifically, the conductive fiber cloth 3 can be immersed in the second adhesive for a period of time (e.g., 5-20 minutes), during which time both sides of the conductive fiber cloth 3 are coated with the second adhesive; alternatively, the second adhesive can be sprayed onto the surface of the conductive fiber cloth 3, thereby adhering the second adhesive to the surface of the conductive fiber cloth 3.

[0031] As shown in Figure 1 or Figure 3, in one embodiment, in step S2 above, the first adhesive is applied to the surfaces of opposite sides of the carbon fiber skeleton 1, and a modified rubber raw rubber layer and a conductive fiber cloth 3 are respectively superimposed on the surfaces of opposite sides of the carbon fiber skeleton 1; thus, a conductive rubber layer 2 and a conductive fiber cloth 3 are formed on the surfaces of opposite sides of the carbon fiber skeleton 1.

[0032] As shown in Figure 2 or Figure 4, in another embodiment, in step S2 above, the first adhesive is disposed on the surface of one side of the carbon fiber skeleton 1, and a modified rubber raw rubber layer and a conductive fiber cloth 3 are superimposed on the surface of the carbon fiber skeleton 1 on the side where the first adhesive is disposed; thus, a conductive rubber layer 2 and a conductive fiber cloth 3 are formed on the surface of one side of the carbon fiber skeleton 1.

[0033] In one embodiment, in step S2 above, the thickness of the carbon fiber skeleton 1 can be 0.5mm to 3mm, the thickness of each modified rubber raw rubber layer can be 0.2mm to 3mm, and the thickness of each conductive fiber cloth 3 can be 0.05mm to 0.2mm.

[0034] As one implementation method, the preparation steps of carbon fiber skeleton 1 in step S1 above include: (1) pressing epoxy resin or bismaleimide resin to form a film, and placing the film on both sides of the carbon fiber fabric to obtain carbon fiber prepreg; (2) stacking multiple layers of carbon fiber prepreg and vacuuming the multiple layers of carbon fiber prepreg to make the carbon fiber prepreg denser to obtain carbon fiber composite; (3) placing the carbon fiber composite in a hot autoclave for curing to obtain carbon fiber skeleton 1; wherein the curing temperature of the carbon fiber composite is 150℃~185℃, the curing time is 3 hours~7 hours, and the curing pressure is 0.3MPa~0.6MPa.

[0035] Specifically, step (1) can be as follows: stir epoxy resin or bismaleimide resin evenly, and then press it into a film by a roller press. The thickness of the film can be 0.05mm~0.1mm. Then, the film is laminated with the carbon fiber fabric by double-sided pressing (that is, after the film and the carbon fiber fabric are stacked on both sides, the film and the carbon fiber fabric are laminated together by roller pressing), thereby obtaining a carbon fiber composite. The carbon fiber fabric can be carbon fiber cloth, carbon fiber tape, etc., and the carbon fiber in the carbon fiber fabric can be high-strength carbon fiber of T300, T700, T800 series, etc. The thickness of the carbon fiber fabric can be 0.05mm~0.2mm.

[0036] In step (2) above, the number of carbon fiber prepreg layers can be determined according to the required thickness of the carbon fiber skeleton 1, for example, 5-15 layers. When vacuuming the multilayer carbon fiber prepreg, vacuuming can be performed after stacking 2-3 layers of carbon fiber prepreg each time (i.e., multiple vacuuming is required in total). The pressure of each vacuuming is, for example, 0.085-0.1 MPa, and the time of each vacuuming is, for example, 15 minutes, so as to better extract the gas between the carbon fiber prepregs and make the carbon fiber prepregs denser.

[0037] In step (3) above, the curing temperature of the carbon fiber composite can be 150℃, 160℃, 170℃, 180℃, 185℃, etc., or any combination of the above temperatures; the curing time can be 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, etc., or any combination of the above times; the curing pressure can be 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, etc., or any combination of the above pressures.

[0038] In addition to step (3) above, the preparation steps of carbon fiber skeleton 1 may also include, according to actual needs, (4) cutting and polishing carbon fiber skeleton 1 according to the design requirements such as the required shape, bending requirements and sealing requirements of the aircraft sealing structure 100, so as to obtain carbon fiber skeleton 1 with a specific shape.

[0039] As one implementation method, the preparation step of conductive fiber cloth 3 in step S1 above includes: applying a conductive material to the surface of multiple fiber filaments to obtain multiple conductive fiber filaments, and then weaving the multiple conductive fiber filaments into conductive fiber cloth 3 (i.e., first attaching a conductive material to the surface of the fiber filaments, and then weaving to obtain conductive fiber cloth 3). The fiber filaments can be one or more of the following: polyester fiber filaments, polyurethane fiber filaments, rubber fiber filaments, polyamide fiber filaments, cotton / linen, etc. (when the fiber filaments are a combination of multiple materials, the conductive fiber cloth 3 can combine the advantages of multiple fiber filaments); the conductive material can be aluminum, silver, graphene, etc., and the conductive material can be applied to the surface of the fiber filaments by spraying, plating (e.g., using PVD physical vapor deposition), soaking, etc.; the weaving method can be plain weave, twill weave, satin weave, etc.

[0040] As another implementation, in step S1 above, the preparation step of the conductive fiber cloth 3 includes: setting a conductive material on the surface of the fiber cloth to obtain the conductive fiber cloth 3 (i.e., first weaving the fiber filaments into a fiber cloth, and then attaching a conductive material to the surface of the fiber cloth to obtain the conductive fiber cloth 3). The fiber cloth is woven from multiple fiber filaments, and the material of the fiber filaments can be one or more of natural fiber filaments such as polyester fiber filaments, polyurethane fiber filaments, rubber fiber filaments, polyamide fiber filaments, cotton / linen, etc. The weaving method can be plain weave, twill weave, satin weave, etc.; the conductive material can be aluminum, silver, graphene, etc., and the conductive material can be applied to the surface of the fiber cloth by spraying, plating (e.g., using PVD physical vapor deposition), immersion, etc.

[0041] In one embodiment, the conductive fiber cloth 3 is an elastic conductive fiber cloth, and the elongation at break of the conductive fiber cloth 3 is not less than 300%, or is 300%~600%. If the elongation at break of the conductive fiber cloth 3 is low, that is, its flexibility is poor, it is prone to breakage during the bending process of the aircraft sealing structure 100, which affects the structural strength, bending resistance and service life of the aircraft sealing structure 100.

[0042] As one implementation, the preparation step of the modified rubber raw rubber layer in step S1 above includes: mixing the raw materials for preparing the modified rubber raw rubber layer (including rubber masterbatch, conductive materials, etc.) evenly to obtain a mixture; and rolling the mixture (for example, using a roller press) to form a sheet-like structure, thereby obtaining the modified rubber raw rubber layer.

[0043] As one implementation method, the raw materials for preparing the modified rubber raw rubber layer also include low-temperature resistant modifying materials. By adding low-temperature resistant modifying materials to the rubber masterbatch, the low-temperature resistance of the conductive rubber layer 2 is improved, making the aircraft sealing structure 100 less prone to damage / breakage even after repeated bending in low-temperature environments. This meets the usage conditions of not being damaged in high-altitude low-temperature flight environments and improves the low-temperature service life of the aircraft sealing structure 100.

[0044] In one implementation, in step S1 above, the rubber masterbatch is methyl vinyl fumed silica (fumed silica is a siloxane polymer obtained by chemical reaction of silicon raw materials at high temperature, and its main component is polydimethylsiloxane. There are two main methods for preparing fumed silica: one is through gas phase reaction, that is, silicon raw materials react with oxygen at high temperature to generate siloxane polymers; the other is through hydrolysis polymerization, that is, silicon raw materials react with water to generate siloxane polymers). The low-temperature resistant modified material includes low-phenyl silicone rubber (when the phenyl content (the ratio of phenyl to silicon atoms) is at a low level (generally 5~10%), it is commonly referred to as low-phenyl silicone rubber). The conductive material includes aluminum-plated fumed silica (fumed silica is silicon hydroxide, with the chemical formula SiO2•xH2O. Aluminum-plated fumed silica means that a layer of aluminum is plated on the surface of fumed silica to make it conductive; aluminum-plated fumed silica is usually prepared by PVD physical vapor deposition, which covers a thin layer of aluminum on the surface of fumed silica). The low-phenyl silicone rubber comprises 15%–25% of the mass of methyl vinyl fumed silica, while the aluminum-coated silica comprises 4%–6% of the mass of the methyl vinyl fumed silica. Specifically, for 100 parts by mass of methyl vinyl fumed silica, the low-phenyl silicone rubber comprises 15–25 parts, and the aluminum-coated silica comprises 4–6 parts. The low-phenyl silicone rubber significantly improves the low-temperature resistance and structural strength of methyl vinyl fumed silica, while the aluminum-coated silica imparts electrical conductivity to the rubber material.

[0045] Meanwhile, in step S1 above, the raw materials for preparing the modified rubber raw rubber layer also include a compatibilizer and a first crosslinking agent. Specifically, the compatibilizer can be a multifunctional vinyl silicone oil, and the first crosslinking agent can be a bis-25 crosslinking agent (i.e., vulcanizing agent bis-25). The compatibilizer can improve the mechanical strength of the rubber material, and the first crosslinking agent can promote the subsequent vulcanization reaction, thereby improving the mechanical strength of the rubber material. The mass of the compatibilizer is 0.5% to 1.5% of the mass of methyl vinyl fumed silica gel, and the mass of the first crosslinking agent is 1.5% to 2.0% of the mass of methyl vinyl fumed silica gel.

[0046] Specifically, the preparation steps of the modified rubber raw rubber layer can be as follows: add 15%~25% low-phenyl silicone rubber, 4%~6% aluminum-coated silicone rubber, 0.5%~1.5% compatibilizer and 1.5%~2.0% first crosslinking agent to methyl vinyl fumed silica gel, mix in a two-roll mill for a period of time (for example, mix at room temperature for 30 minutes) to obtain a mixture; then roll the mixture to form a sheet structure, thus obtaining the modified rubber raw rubber layer.

[0047] In one embodiment, the mass of the low-phenyl silicone rubber can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% of the mass of methyl vinyl fumed silica, or any combination thereof. The mass of the aluminum-coated fumed silica can be 4%, 4.5%, 5%, 5.5%, 6% of the mass of methyl vinyl fumed silica, or any combination thereof. The mass of the compatibilizer can be 0.5%, 1%, 1.5% of the mass of methyl vinyl fumed silica, or any combination thereof. The mass of the first crosslinking agent can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0% of the mass of methyl vinyl fumed silica, or any combination thereof.

[0048] (1) In order to verify the effect of low-phenyl silicone rubber on the low-temperature modification of methyl vinyl fumed silica, the following experiment was designed: 1. 20% low-phenyl silicone rubber, 5% aluminum-coated fumed silica and 1% compatibilizer (multifunctional vinyl silicone oil) were added to methyl vinyl fumed silica. After mixing evenly, the mixture was rolled into sheets and then vulcanized (vulcanization temperature was 160℃, vulcanization time was 30 minutes and vulcanization pressure was 15 MPa) to obtain a conductive rubber layer.

[0049] 2. Add 5% aluminum-coated fumed silica and 1% compatibilizer (multifunctional vinyl silicone oil) to methyl vinyl fumed silica gel. After mixing evenly, roll it into a sheet and then vulcanize it (vulcanization temperature is 160℃, vulcanization time is 30 minutes, vulcanization pressure is 15 MPa) to obtain the first rubber layer.

[0050] The thickness of both the conductive rubber layer and the first rubber layer is 2 mm.

[0051] The glass transition temperatures of the conductive rubber layer and the first rubber layer were tested separately. (The glass transition temperature of rubber refers to the temperature at which a rubber material transitions from a highly elastic state to a glassy state; below this temperature, the rubber exhibits brittleness, while above this temperature, the rubber exhibits elasticity.) The test standards are as follows: Glass transition temperature: Tested according to GB / T19466.2-2004 Part 2, Determination of Glass Transition Temperature.

[0052] The test results are shown in the table below: As can be seen from the table above, after modification (with the addition of low-phenyl silicone rubber), the glass transition temperature of the rubber material is significantly reduced, meaning that the low-temperature resistance of the rubber material is significantly enhanced. This indicates that low-phenyl silicone rubber can significantly improve the low-temperature resistance of methyl vinyl fumed silica.

[0053] (2) To verify the combined performance (including elongation at break and conductivity) of the conductive rubber layer and conductive fiber cloth prepared by the above materials, the following experiment was designed: 1. 20% low-phenyl silicone rubber, 5% aluminum-plated silica gel and 1% compatibilizer (multifunctional vinyl silicone oil) were added to methyl vinyl fumed silica gel. After mixing evenly, the mixture was rolled into sheets to obtain a modified rubber raw rubber layer; 2. Aluminum was plated on the surfaces of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminum-plated polyurethane fiber filaments and aluminum-plated polyamide fiber filaments. The aluminum-plated polyurethane fiber filaments and aluminum-plated polyamide fiber filaments were then woven into a conductive fiber cloth; wherein the conductive fiber cloth contained 35% (mass content) aluminum-plated polyurethane fiber filaments and 65% aluminum-plated polyamide fiber filaments, and the thickness of the conductive fiber cloth was [missing information]. 0.1mm, and the tensile elongation at break of the conductive fiber cloth is 300%; 3. Soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the conductive fiber cloth with the modified rubber raw rubber layer, specifically stacking in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain a composite; then put the composite into a vulcanizing machine for vulcanization treatment to obtain a conductive rubber-conductive fiber cloth composite, the overall thickness of the conductive rubber-conductive fiber cloth composite is 1mm (the thickness of the composite after stacking is controlled by the mold, and the excess modified rubber raw rubber layer will be extruded, thereby controlling the final thickness of the conductive rubber-conductive fiber cloth composite); wherein, the vulcanization temperature is 160℃, the vulcanization time is 30 minutes, and the vulcanization pressure is 15Mpa.

[0054] The elongation at break and sheet resistance (i.e., sheet resistance) of the conductive rubber-conductive fiber cloth composite were tested separately. The test standards for each index are as follows: Elongation at break: Tested in accordance with GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber.

[0055] Sheet resistance: Sheet resistance is tested using a four-probe tester (specifically, the probe of the four-probe tester is brought into contact with the surface of the conductive rubber-conductive fiber cloth composite to read the sheet resistance data; the measurement is repeated multiple times, generally at least three times, to obtain multiple sets of data, and then the average value is taken).

[0056] The test results are shown in the table below: As can be seen from the table above, the elongation at break of the conductive rubber-conductive fiber cloth composite is over 150%, indicating that it has good deformation properties; at the same time, the sheet resistance of the conductive rubber-conductive fiber cloth composite is 20Ω / sq, and its conductivity meets the relevant requirements.

[0057] In another embodiment, in step S1 above, the rubber masterbatch is hydrogenated nitrile butadiene rubber (specifically, it can be hydrogenated nitrile butadiene rubber with low acrylonitrile content), the low-temperature resistant modifier includes dioctyl adipate (DOA) and hydrogenated nitrile butadiene liquid (specifically, it can be a large-molecule liquid hydrogenated nitrile butadiene), and the conductive material includes aluminum-coated silica. Both dioctyl adipate and hydrogenated nitrile butadiene liquid are plasticizers. Both can improve the low-temperature resistance of hydrogenated nitrile butadiene rubber, and the hydrogenated nitrile butadiene liquid can also increase the crosslinking density of the rubber, thereby improving the structural strength of the rubber material; the aluminum-coated silica enables the rubber material to be conductive. The mass of dioctyl adipate is 1.5% to 2.5% of the mass of hydrogenated nitrile butadiene rubber, specifically 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, etc., or any combination of the above percentages; the mass of hydrogenated nitrile butadiene liquid is 0.5% to 1.5% of the mass of hydrogenated nitrile butadiene rubber, specifically 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., or any combination of the above percentages; the mass of aluminum-coated silica is 4% to 6% of the mass of hydrogenated nitrile butadiene rubber, specifically 4%, 4.5%, 5%, 5.5%, 6%, etc., or any combination of the above percentages.

[0058] Meanwhile, in the above step S1, the raw materials for preparing the modified rubber raw rubber layer further include a reinforcing agent, an activator, an anti-aging agent, a promoter, and a second cross-linking agent. The reinforcing agent includes one or more of carbon black and silica; the activator includes one or more of zinc oxide and stearic acid; the anti-aging agent includes one or more of antioxidant anti-aging agent D, anti-ozone anti-aging agent 4010NA, and paraffin wax; the promoter includes triallyl isocyanurate (TAIC); the second cross-linking agent includes dicumyl peroxide (DCP). The reinforcing agent can improve the mechanical strength of the rubber material; the activator and the promoter can promote the cross-linking reaction and improve the mechanical strength of the rubber material; the anti-aging agent can improve the anti-aging performance of the rubber material; the second cross-linking agent can promote the subsequent vulcanization reaction and improve the mechanical strength of the rubber material. Among them, the mass of the reinforcing agent is 30% - 40% of the mass of hydrogenated nitrile rubber, specifically it can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, etc., and can also be any combination range of the above percentages; the mass of the activator is 2.5% - 6.5% of the mass of hydrogenated nitrile rubber, specifically it can be 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, etc., and can also be any combination range of the above percentages; the mass of the anti-aging agent is 1% - 2% of the mass of hydrogenated nitrile rubber, specifically it can be 1%, 1.5%, 2%, etc., and can also be any combination range of the above percentages; the mass of the promoter is 0.5% - 1.5% of the mass of hydrogenated nitrile rubber, specifically it can be 0.5%, 1%, 1.5%, etc., and can also be any combination range of the above percentages; the mass of the second cross-linking agent is 3% - 5% of the mass of hydrogenated nitrile rubber, specifically it can be 3%, 3.5%, 4%, 4.5%, etc., and can also be any combination range of the above percentages.

[0059] Specifically, the preparation steps of the modified rubber raw rubber layer can be as follows: Add 1.5% - 2.5% of dioctyl adipate, 0.5% - 1.5% of hydrogenated nitrile liquid, 4% - 6% of aluminum-coated fumed silica, 30% - 40% of the reinforcing agent, 2.5% - 6.5% of the activator, and 1% - 2% of the anti-aging agent to hydrogenated nitrile rubber, heat and mix in a mixer for a period of time (for example, mix at 190°C), then add 0.5% - 1.5% of the promoter and 3% - 5% of the second cross-linking agent, and mix in an open mill for a period of time (for example, mix at room temperature for 20 minutes) to obtain a mixture (it should be noted that the promoter and the second cross-linking agent cannot be heated and mixed in the mixer, as they will decompose at high temperatures and cause the cross-linking reaction to occur prematurely); then roll the mixture to make the mixture form a sheet structure, thus obtaining the modified rubber raw rubber layer.

[0060] (1) In order to verify the effect of dioctyl adipate and hydrogenated nitrile liquid on the low-temperature resistance modification of hydrogenated nitrile rubber, the following experiment was designed: 1. 2% dioctyl adipate, 1% hydrogenated nitrile liquid and 5% aluminum-coated silica were added to hydrogenated nitrile rubber, mixed evenly and rolled into sheets, and then vulcanized (vulcanization temperature was 180℃, vulcanization time was 20 minutes and vulcanization pressure was 15 MPa) to obtain a conductive rubber layer.

[0061] 2. Add 5% aluminum-coated silica to hydrogenated nitrile rubber, mix evenly, roll into sheet, and then vulcanize (vulcanization temperature is 180℃, vulcanization time is 20 minutes, vulcanization pressure is 15 MPa) to obtain the second rubber layer.

[0062] The thickness of both the conductive rubber layer and the second rubber layer is 2 mm.

[0063] The glass transition temperatures of the conductive rubber layer and the second rubber layer were tested separately, using the same testing standards as described above.

[0064] The test results are shown in the table below: As can be seen from the table above, after modification (addition of dioctyl adipate and hydrogenated nitrile butadiene rubber liquid), the glass transition temperature of the rubber material is significantly reduced, that is, the low-temperature resistance of the rubber material is significantly enhanced. This indicates that both dioctyl adipate and hydrogenated nitrile butadiene rubber liquid can improve the low-temperature resistance of hydrogenated nitrile butadiene rubber.

[0065] (2) To verify the combined performance (including elongation at break and conductivity) of the conductive rubber layer and conductive fiber cloth made from the above materials, the following experiment was designed: 1. 2% dioctyl adipate, 1% hydrogenated nitrile butadiene rubber liquid, and 5% aluminum-coated silica were added to hydrogenated nitrile butadiene rubber, mixed evenly, and then rolled into sheets to obtain a modified rubber raw rubber layer; 2. Aluminum was coated on the surfaces of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminum-coated polyurethane fiber filaments and aluminum-coated polyamide fiber filaments, which were then woven into a conductive fiber cloth; wherein the conductive fiber cloth contained 50% (by mass) aluminum-coated polyurethane fiber filaments and The conductive fiber cloth consists of 50% aluminized polyamide fibers, with a thickness of 0.1 mm and a tensile elongation of 350%. The conductive fiber cloth is then soaked in isocyanate adhesive for 20 minutes. It is then layered with a modified rubber raw rubber layer, specifically in the order of modified rubber raw rubber layer - conductive fiber cloth - modified rubber raw rubber layer, to obtain a composite. This composite is then placed in a vulcanizing machine for vulcanization to obtain a conductive rubber-conductive fiber cloth composite with an overall thickness of 1 mm. The vulcanization temperature is 180℃, the vulcanization time is 20 minutes, and the vulcanization pressure is 15 MPa.

[0066] The tensile elongation at break and sheet resistance (i.e., sheet resistance) of the conductive rubber-conductive fiber cloth composite were tested separately, and the testing standards for each indicator were the same as those mentioned above.

[0067] The test results are shown in the table below: As can be seen from the table above, the elongation at break of the conductive rubber-conductive fiber cloth composite is over 150%, indicating that it has good deformation properties; at the same time, the sheet resistance of the conductive rubber-conductive fiber cloth composite is 15Ω / sq, and its conductivity meets the relevant requirements.

[0068] As shown in Figure 1, in one embodiment, in step S3 above, after the intermediate is vulcanized, a primer layer 4 and a wear-resistant coating 5 are sequentially applied to at least one side of the surface of the intermediate. The wear-resistant coating 5 improves the wear resistance of the aircraft sealing structure 100, and the primer layer 4 improves the adhesion of the wear-resistant coating 5, preventing it from detaching (if the wear-resistant coating 5 is directly applied to the conductive rubber layer 2, the conductive fiber cloth 3, or the carbon fiber skeleton 1, the wear-resistant coating 5 may detach due to insufficient adhesion to the conductive rubber layer 2 / conductive fiber cloth 3 / carbon fiber skeleton 1). Preferably, the primer layer 4 and the wear-resistant coating 5 are disposed on the surfaces of opposite sides of the intermediate body, so that both sides of the aircraft sealing structure 100 have the primer layer 4 and the wear-resistant coating 5 (when conductive rubber layer 2 and conductive fiber cloth 3 are formed on the surfaces of opposite sides of the carbon fiber skeleton 1, as shown in FIG1, the primer layer 4 and the wear-resistant coating 5 are disposed on the surfaces of the conductive rubber layer 2 on opposite sides; or, as shown in FIG3, the primer layer 4 and the wear-resistant coating 5 are disposed on the surfaces of the conductive fiber cloth 3 on opposite sides. When conductive rubber layer 2 and conductive fiber cloth 3 are formed on one side of the surface of the carbon fiber skeleton 1, as shown in FIG2, the primer layer 4 and the wear-resistant coating 5 are disposed on the surface of the conductive rubber layer 2 and the surface of the carbon fiber skeleton 1; or, as shown in FIG4, the primer layer 4 and the wear-resistant coating 5 are disposed on the surface of the conductive fiber cloth 3 and the surface of the carbon fiber skeleton 1). The primer layer 4 and the wear-resistant coating 5 can be formed by spraying. The material of the primer layer 4 can be an epoxy resin-based material, and the wear-resistant coating 5 can be a material based on boron nitride, silicon carbide, etc. The thickness of the primer layer 4 can be 10~25 micrometers, and the thickness of the wear-resistant coating layer 5 can be 20~60 micrometers.

[0069] Specifically, during manufacturing, the vulcanized intermediate body can be trimmed and sanded first, then a primer layer 4 can be sprayed onto the surface of the intermediate body. After the primer layer 4 dries and cures, a wear-resistant coating layer 5 can be sprayed on. It should be noted that when the primer layer 4 and the wear-resistant coating layer 5 are applied to the surface of the aircraft sealing structure 100, electromagnetic waves can penetrate the primer layer 4 and the wear-resistant coating layer 5 to reach the conductive rubber layer 2 / conductive fiber cloth 3. Therefore, electromagnetic waves can still smoothly transition on the surface of the aircraft sealing structure 100, thereby ensuring the continuity of electromagnetic waves traveling on the wing surface. At the same time, in order to reduce the obstruction of electromagnetic wave penetration by the primer layer 4 and the wear-resistant coating layer 5, the thickness of the primer layer 4 and the wear-resistant coating layer 5 is relatively thin, and the primer layer 4 and the wear-resistant coating layer 5 can be made of materials with a low dielectric constant.

[0070] This invention also provides an aircraft sealing structure 100, which is manufactured using the aircraft sealing structure preparation method described above; the aircraft sealing structure 100 includes a carbon fiber skeleton 1 and a conductive rubber layer 2 and a conductive fiber cloth 3 disposed on at least one side surface of the carbon fiber skeleton 1.

[0071] Example 1 (1) Preparation of carbon fiber skeleton: The epoxy resin was stirred evenly and then pressed by a roller press to form a film with a thickness of 0.1 mm; then the film was laminated with both sides of the carbon fiber fabric by double-sided pressing (the carbon fiber in the carbon fiber fabric is T700 series and the thickness of the carbon fiber fabric is 0.15 mm) to obtain a carbon fiber prepreg with a thickness of 0.2 mm.

[0072] Seven layers of carbon fiber prepreg were stacked and then vacuum-treated to densify the carbon fiber prepregs, resulting in a carbon fiber composite. During the vacuum treatment, a vacuum was applied after stacking 2-3 layers of carbon fiber prepreg each time, with a pressure of 0.085 MPa and a duration of 15 minutes for each vacuum treatment.

[0073] The carbon fiber composite was placed in an autoclave for curing to obtain a carbon fiber skeleton with a thickness of 1.5 mm. The curing temperature of the carbon fiber composite was 180℃, the curing time was 4 hours, and the curing pressure was 0.4 MPa.

[0074] (2) Preparation of modified rubber raw rubber layer: 20% low phenyl silicone rubber, 5% aluminum-plated silicone and 1% compatibilizer (multifunctional vinyl silicone oil) are added to methyl vinyl fumed silica gel. After mixing evenly, the mixture is rolled into sheet-like modified rubber raw rubber layer.

[0075] (3) Preparation of conductive fiber cloth: Aluminum is plated on the surface of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments. The aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments are woven into conductive fiber cloth; wherein the conductive fiber cloth contains 35% (mass content) aluminized polyurethane fiber filaments and 65% aluminized polyamide fiber filaments, and the thickness of the conductive fiber cloth is 0.1 mm.

[0076] (4) Soak the carbon fiber skeleton in epoxy resin adhesive for 20 minutes, soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the modified rubber raw rubber layer and the conductive fiber cloth on both sides of the carbon fiber skeleton respectively. Specifically, each side of the carbon fiber skeleton is stacked in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain an intermediate body; then put the intermediate body into a vulcanizing machine for vulcanization treatment to obtain sealing structure sample 1. The overall thickness of sealing structure sample 1 is 2mm (the thickness of the intermediate body after stacking is controlled by the mold, and the excess modified rubber raw rubber layer will be squeezed out, thereby controlling the thickness of the final sealing structure sample); the vulcanization temperature is 160℃, the vulcanization time is 30 minutes, and the vulcanization pressure is 15Mpa.

[0077] Example 2 (1) Preparation of carbon fiber skeleton: The epoxy resin was stirred evenly and then pressed by a roller press to form a film with a thickness of 0.1 mm; then the film was laminated with both sides of the carbon fiber fabric by double-sided pressing (the carbon fiber in the carbon fiber fabric is T700 series and the thickness of the carbon fiber fabric is 0.15 mm) to obtain a carbon fiber prepreg with a thickness of 0.2 mm.

[0078] Seven layers of carbon fiber prepreg were stacked and then vacuum-treated to densify the carbon fiber prepregs, resulting in a carbon fiber composite. During the vacuum treatment, a vacuum was applied after stacking 2-3 layers of carbon fiber prepreg each time, with a pressure of 0.085 MPa and a duration of 15 minutes for each vacuum treatment.

[0079] The carbon fiber composite was placed in an autoclave for curing to obtain a carbon fiber skeleton with a thickness of 1.5 mm. The curing temperature of the carbon fiber composite was 180℃, the curing time was 4 hours, and the curing pressure was 0.4 MPa.

[0080] (2) Preparation of modified rubber raw rubber layer: 20% low phenyl silicone rubber, 5% aluminum-plated silicone, 1% compatibilizer (multifunctional vinyl silicone oil) and 1.5% bis-25 crosslinking agent are added to methyl vinyl fumed silica gel. After mixing evenly, the mixture is rolled into a sheet-like modified rubber raw rubber layer (i.e., compared with Example 1, Example 2 has added more bis-25 crosslinking agent).

[0081] (3) Preparation of conductive fiber cloth: Aluminum is plated on the surface of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments. The aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments are woven into conductive fiber cloth; wherein the conductive fiber cloth contains 35% (mass content) aluminized polyurethane fiber filaments and 65% aluminized polyamide fiber filaments, and the thickness of the conductive fiber cloth is 0.1 mm.

[0082] (4) Soak the carbon fiber skeleton in epoxy resin adhesive for 20 minutes, soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the modified rubber raw rubber layer and the conductive fiber cloth on both sides of the carbon fiber skeleton respectively. Specifically, each side of the carbon fiber skeleton is stacked in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain an intermediate body. Then, put the intermediate body into a vulcanizing machine for vulcanization treatment to obtain sealing structure sample 2. The overall thickness of sealing structure sample 2 is 2 mm. The vulcanization temperature is 160℃, the vulcanization time is 30 minutes, and the vulcanization pressure is 15 MPa.

[0083] Example 3 (1) Preparation of carbon fiber skeleton: The epoxy resin was stirred evenly and then pressed by a roller press to form a film with a thickness of 0.1 mm. Then, the film was laminated with both sides of the carbon fiber fabric by double-sided pressing (the carbon fiber in the carbon fiber fabric is T700 series and the thickness of the carbon fiber fabric is 0.15 mm) to obtain a carbon fiber prepreg with a thickness of 0.2 mm.

[0084] Seven layers of carbon fiber prepreg were stacked and then vacuum-treated to densify the carbon fiber prepregs, resulting in a carbon fiber composite. During the vacuum treatment, a vacuum was applied after stacking 2-3 layers of carbon fiber prepreg each time, with a pressure of 0.085 MPa and a duration of 15 minutes for each vacuum treatment.

[0085] The carbon fiber composite was placed in an autoclave for curing to obtain a carbon fiber skeleton with a thickness of 1.5 mm. The curing temperature of the carbon fiber composite was 180℃, the curing time was 4 hours, and the curing pressure was 0.4 MPa.

[0086] (2) Preparation of modified rubber raw rubber layer: 2% dioctyl adipate, 1% hydrogenated nitrile liquid and 5% aluminum-coated silica are added to hydrogenated nitrile rubber, mixed evenly and then rolled into sheet-like modified rubber raw rubber layer.

[0087] (3) Preparation of conductive fiber cloth: Aluminum is plated on the surface of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments. The aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments are woven into conductive fiber cloth; wherein the conductive fiber cloth contains 30% (mass content) aluminized polyurethane fiber filaments and 70% aluminized polyamide fiber filaments, and the thickness of the conductive fiber cloth is 0.1 mm.

[0088] (4) Soak the carbon fiber skeleton in epoxy resin adhesive for 20 minutes, soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the modified rubber raw rubber layer and conductive fiber cloth on both sides of the carbon fiber skeleton respectively. Specifically, each side of the carbon fiber skeleton is stacked in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain an intermediate body. Then, put the intermediate body into a vulcanizing machine for vulcanization treatment to obtain the sealing structure sample 3. The overall thickness of the sealing structure sample 3 is 2 mm. The vulcanization temperature is 180℃, the vulcanization time is 20 minutes, and the vulcanization pressure is 15 MPa.

[0089] Example 4 (1) Preparation of carbon fiber skeleton: The epoxy resin was stirred evenly and then pressed by a roller press to form a film with a thickness of 0.1 mm. Then, the film was laminated with both sides of the carbon fiber fabric by double-sided pressing (the carbon fiber in the carbon fiber fabric is T700 series and the thickness of the carbon fiber fabric is 0.15 mm) to obtain a carbon fiber prepreg with a thickness of 0.2 mm.

[0090] Seven layers of carbon fiber prepreg were stacked and then vacuum-treated to densify the carbon fiber prepregs, resulting in a carbon fiber composite. During the vacuum treatment, a vacuum was applied after stacking 2-3 layers of carbon fiber prepreg each time, with a pressure of 0.085 MPa and a duration of 15 minutes for each vacuum treatment.

[0091] The carbon fiber composite was placed in an autoclave for curing to obtain a carbon fiber skeleton with a thickness of 1.5 mm. The curing temperature of the carbon fiber composite was 180℃, the curing time was 4 hours, and the curing pressure was 0.4 MPa.

[0092] (2) Preparation of modified rubber raw rubber layer: 2% dioctyl adipate, 1% hydrogenated nitrile butadiene liquid, 5% aluminum-coated silica, 30% reinforcing agent (silica), 5% activator (zinc oxide) and 1% antioxidant (antioxidant D) are added to hydrogenated nitrile butadiene rubber. The mixture is heated to 190°C in a mixer and then 1% accelerator (triallyl isocyanurate) and 3% crosslinking agent (diisopropylbenzene peroxide) are added. The mixture is mixed at room temperature in a two-roll mill for 20 minutes to obtain a mixture. The mixture is then rolled to form a sheet structure, which is the modified rubber raw rubber layer (i.e., compared with Example 3, Example 4 has added more reinforcing agent, activator, antioxidant, accelerator and crosslinking agent).

[0093] (3) Preparation of conductive fiber cloth: Aluminum is plated on the surface of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments. The aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments are woven into conductive fiber cloth; wherein the conductive fiber cloth contains 30% (mass content) aluminized polyurethane fiber filaments and 70% aluminized polyamide fiber filaments, and the thickness of the conductive fiber cloth is 0.1 mm.

[0094] (4) Soak the carbon fiber skeleton in epoxy resin adhesive for 20 minutes, soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the modified rubber raw rubber layer and conductive fiber cloth on both sides of the carbon fiber skeleton respectively. Specifically, each side of the carbon fiber skeleton is stacked in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain an intermediate body. Then, put the intermediate body into a vulcanizing machine for vulcanization treatment to obtain the sealing structure sample 4. The overall thickness of the sealing structure sample 4 is 2 mm. The vulcanization temperature is 180℃, the vulcanization time is 20 minutes, and the vulcanization pressure is 15 MPa.

[0095] The tensile strength of sealed structure samples 1-4 was tested, and the test standards for each index are as follows: Tensile strength: Tested according to GB / T 3354-1999 Test method for tensile properties of oriented fiber reinforced plastics.

[0096] The test results are shown in the table below: As can be seen from the table above, all four sealing structure samples 1-4 have good tensile strength, and their structural strength meets the requirements.

[0097] Meanwhile, sealed structure samples 1-4 were subjected to repeated bending tests (bending angle ±60°) at temperatures of -30°C, -40°C, and 25°C, respectively, until the samples broke / fractured. The number of bends for each sample was recorded (the more bends, the higher the structural strength and the better the fatigue resistance). The test results are shown in the table below: As can be seen from the table above, under temperature conditions of -30℃, -40℃ and 25℃, the sealing structure samples 1-4 can all achieve a high number of bending cycles, indicating that the aircraft sealing structure prepared by the method of the present invention has good structural strength, bending resistance and fatigue resistance, regardless of whether it is in a low temperature environment or a normal temperature environment.

[0098] Example 5 (1) Preparation of carbon fiber skeleton: The epoxy resin was stirred evenly and then pressed by a roller press to form a film with a thickness of 0.1 mm; then the film was laminated with both sides of the carbon fiber fabric by double-sided pressing (the carbon fiber in the carbon fiber fabric is T700 series and the thickness of the carbon fiber fabric is 0.15 mm) to obtain a carbon fiber prepreg with a thickness of 0.2 mm.

[0099] Seven layers of carbon fiber prepreg were stacked and then vacuum-treated to densify the carbon fiber prepregs, resulting in a carbon fiber composite. During the vacuum treatment, a vacuum was applied after stacking 2-3 layers of carbon fiber prepreg each time, with a pressure of 0.085 MPa and a duration of 15 minutes for each vacuum treatment.

[0100] The carbon fiber composite was placed in an autoclave for curing to obtain a carbon fiber skeleton with a thickness of 1.5 mm. The curing temperature of the carbon fiber composite was 180℃, the curing time was 4 hours, and the curing pressure was 0.4 MPa.

[0101] (2) Preparation of modified rubber raw rubber layer: 2% dioctyl adipate, 1% hydrogenated nitrile liquid and 5% aluminum-coated silica are added to hydrogenated nitrile rubber, mixed evenly and then rolled into sheet-like modified rubber raw rubber layer.

[0102] (3) Preparation of conductive fiber cloth: Aluminum is plated on the surface of polyurethane fiber filaments and polyamide fiber filaments to obtain aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments. The aluminized polyurethane fiber filaments and aluminized polyamide fiber filaments are woven into conductive fiber cloth; wherein the conductive fiber cloth contains 30% (mass content) aluminized polyurethane fiber filaments and 70% aluminized polyamide fiber filaments, and the thickness of the conductive fiber cloth is 0.1 mm.

[0103] (4) Soak the carbon fiber skeleton in epoxy resin adhesive for 20 minutes, soak the conductive fiber cloth in isocyanate adhesive for 20 minutes, and then stack the modified rubber raw rubber layer and the conductive fiber cloth on both sides of the carbon fiber skeleton respectively. Specifically, each side of the carbon fiber skeleton is stacked in the order of modified rubber raw rubber layer-conductive fiber cloth-modified rubber raw rubber layer to obtain an intermediate body. Then, put the intermediate body into a vulcanizing machine for vulcanization treatment. The overall thickness of the intermediate body after vulcanization treatment is 2 mm. The vulcanization temperature is 180℃, the vulcanization time is 20 minutes, and the vulcanization pressure is 15 MPa.

[0104] (5) After the intermediate is vulcanized, a 10-micron primer layer (epoxy resin primer layer) and a 20-micron wear-resistant coating layer (silicon carbide wear-resistant coating layer) are sprayed on both sides of the intermediate to obtain sealing structure sample 5 (that is, sealing structure sample 5 is based on sealing structure sample 3 with an additional primer layer and wear-resistant coating layer). The size of sealing structure sample 5 is 300mm*100mm*2mm.

[0105] The abrasion resistance of the sealing structure sample 5 was tested according to the method of ASTM D4060 abrasion resistance test standard (CS-10 wheel, 1000g load, 1000 cycles). The mass loss of the sealing structure sample 5 was less than 2g, which shows that it has good abrasion resistance.

[0106] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an aircraft sealing structure, characterized in that, Includes the following steps: S1: Prepare a carbon fiber skeleton, a modified rubber raw rubber layer, and a conductive fiber cloth; wherein the raw materials for preparing the modified rubber raw rubber layer include rubber masterbatch and conductive materials; S2: Apply a first adhesive to at least one surface of the carbon fiber skeleton, and apply a second adhesive to at least one surface of the conductive fiber cloth; stack the modified rubber raw rubber layer and the conductive fiber cloth on at least one surface of the carbon fiber skeleton, such that the modified rubber raw rubber layer is located on opposite sides of the conductive fiber cloth, or the modified rubber raw rubber layer is located between the carbon fiber skeleton and the conductive fiber cloth. An intermediate body is obtained between the conductive fiber cloths; wherein the carbon fiber skeleton is pre-bonded to the modified rubber raw rubber layer by the first adhesive, and the conductive fiber cloth is pre-bonded to the modified rubber raw rubber layer by the second adhesive; S3: the intermediate body is vulcanized to obtain the aircraft sealing structure, wherein the modified rubber raw rubber layer in the intermediate body forms a conductive rubber layer after vulcanization; wherein the vulcanization temperature of the intermediate body is 150℃~190℃, the vulcanization time is 10 minutes~60 minutes, and the vulcanization pressure is 15MPa~20MPa.

2. The method for preparing the aircraft sealing structure as described in claim 1, characterized in that, In step S1 above, the raw materials for preparing the modified rubber raw rubber layer also include a low-temperature resistant modifying material; the rubber masterbatch is methyl vinyl fumed silica gel, the low-temperature resistant modifying material includes low-phenyl silicone rubber, and the conductive material includes aluminum-plated fumed silica gel; wherein, the mass of the low-phenyl silicone rubber is 15% to 25% of the mass of the methyl vinyl fumed silica gel, and the mass of the aluminum-plated fumed silica gel is 4% to 6% of the mass of the methyl vinyl fumed silica gel.

3. The method for preparing the aircraft sealing structure as described in claim 2, characterized in that, In step S1 above, the raw materials for preparing the modified rubber raw rubber layer also include a compatibilizer and a first crosslinking agent; wherein the mass of the compatibilizer is 0.5% to 1.5% of the mass of the methyl vinyl fumed silica gel, and the mass of the first crosslinking agent is 1.5% to 2.0% of the mass of the methyl vinyl fumed silica gel.

4. The method for preparing the aircraft sealing structure as described in claim 1, characterized in that, In step S1 above, the raw materials for preparing the modified rubber raw rubber layer also include a low-temperature resistant modifying material; the rubber masterbatch is hydrogenated nitrile butadiene rubber, the low-temperature resistant modifying material includes dioctyl adipate and hydrogenated nitrile butadiene liquid, and the conductive material includes aluminum-plated fumed silica; wherein, the mass of dioctyl adipate is 1.5%~2.5% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the hydrogenated nitrile butadiene liquid is 0.5%~1.5% of the mass of the hydrogenated nitrile butadiene rubber, and the mass of aluminum-plated fumed silica is 4%~6% of the mass of the hydrogenated nitrile butadiene rubber.

5. The method for preparing the aircraft sealing structure as described in claim 4, characterized in that, In step S1 above, the raw materials for preparing the modified rubber raw rubber layer further include a reinforcing agent, an activator, an antioxidant, an accelerator, and a second crosslinking agent; wherein the mass of the reinforcing agent is 30% to 40% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the activator is 2.5% to 6.5% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the antioxidant is 1% to 2% of the mass of the hydrogenated nitrile butadiene rubber, the mass of the accelerator is 0.5% to 1.5% of the mass of the hydrogenated nitrile butadiene rubber, and the mass of the second crosslinking agent is 3% to 5% of the mass of the hydrogenated nitrile butadiene rubber.

6. The method for preparing the aircraft sealing structure as described in claim 1, characterized in that, In step S1 above, the preparation steps of the carbon fiber skeleton include: (1) pressing epoxy resin or bismaleimide resin to form a film, and placing the film on both sides of the carbon fiber fabric to obtain carbon fiber prepreg; (2) stacking multiple layers of the carbon fiber prepreg and vacuuming the multiple layers of the carbon fiber prepreg to obtain a carbon fiber composite; (3) placing the carbon fiber composite in a hot autoclave for curing to obtain the carbon fiber skeleton; wherein, the curing temperature of the carbon fiber composite is 150℃~185℃, the curing time is 3 hours~7 hours, and the curing pressure is 0.3MPa~0.6MPa.

7. The method for preparing the aircraft sealing structure as described in claim 1, characterized in that, In step S1 above, the preparation step of the conductive fiber cloth includes: setting a conductive material on the surface of the fiber filament to obtain conductive fiber filament, and then weaving the conductive fiber filament into the conductive fiber cloth; or, setting a conductive material on the surface of the fiber cloth to obtain the conductive fiber cloth.

8. The method for preparing the aircraft sealing structure as described in claim 1, characterized in that, In step S2 above, the first adhesive is an epoxy resin adhesive, and the second adhesive is an isocyanate adhesive; the first adhesive is disposed on one side of the carbon fiber skeleton, and the modified rubber raw rubber layer and the conductive fiber cloth are superimposed on the surface of the carbon fiber skeleton on the side where the first adhesive is disposed; or, the first adhesive is disposed on the surfaces of opposite sides of the carbon fiber skeleton, and the modified rubber raw rubber layer and the conductive fiber cloth are superimposed on both sides of the carbon fiber skeleton respectively.

9. The method for preparing the aircraft sealing structure as described in any one of claims 1-8, characterized in that, In step S3 above, after the intermediate is vulcanized, a primer layer and a wear-resistant coating are sequentially applied to at least one side of the surface of the intermediate.

10. An aircraft sealing structure, characterized in that, The aircraft sealing structure is manufactured using the preparation method of any one of claims 1-9; the aircraft sealing structure includes a carbon fiber skeleton and a conductive rubber layer and a conductive fiber cloth disposed on at least one surface of the carbon fiber skeleton.

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