Phenolic gasket and manufacturing method thereof

Abstract

The invention relates to the technical field of airplane fuel tank sealing, in particular to a phenolic aldehyde gasket applied to an airplane fuel tank covering cap structure connecting piece and a manufacturing method of the phenolic aldehyde gasket, the phenolic aldehyde gasket comprises a phenolic aldehyde layer and a protective coating, the phenolic aldehyde layer and the protective coating are tightly bonded, and the protective coating comprises a polytetrafluoroethylene layer and / or a polyurethane layer. The polytetrafluoroethylene layer can provide excellent wear resistance and solvent resistance, and the polyurethane layer can enhance moisture resistance, mildew resistance and electrical isolation functions. The polytetrafluoroethylene layer and / or the polyurethane layer and the phenolic resin layer are tightly bonded to form the novel phenolic aldehyde gasket with a composite structure, and multiple advantages of a protective coating can be combined to provide more comprehensive protection for the phenolic aldehyde gasket, so that the performance of the phenolic aldehyde gasket is remarkably improved, and strict requirements of modern air transportation on material performance are met.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft fuel tank sealing, and in particular to a phenolic gasket applied to an aircraft fuel tank cover structural connector and a manufacturing method thereof. Background Art

[0002] With the continuous development of the aviation transportation industry, higher and higher requirements are placed on the durability and safety of various components used in aircraft. As we all know, the fuel system of an aircraft is an important part of the aircraft. It is responsible for storing and transporting fuel and providing power for the aircraft's engine. As a key component in the structural connector of the aircraft fuel tank maintenance cover, the stability of the performance and quality of phenolic gaskets will directly affect the operational safety of the fuel system, so the requirements for their protective performance are becoming more and more stringent.

[0003] At present, phenolic gaskets need to be immersed in aviation fuel for a long time during use, which makes them susceptible to chemical corrosion, leading to material degradation, thereby reducing the sealing performance of the aircraft fuel tank and increasing the risk of fuel leakage. This situation is particularly serious under high temperature and high pressure environments, and may even affect flight safety. Moreover, phenolic gaskets need to deal with the frequent opening and closing of maintenance covers during use, which may cause surface wear and further affect their sealing effect. In addition, the performance of existing phenolic gaskets in terms of high temperature resistance, wear resistance, pressure resistance, moisture resistance, mildew resistance, and electrical isolation function is also relatively limited, and cannot meet the higher requirements of modern air transportation for material performance. Summary of the invention

[0004] In view of this, the present invention proposes a phenolic gasket used in an aircraft fuel tank cover structural connector and a manufacturing method thereof, aiming to solve the problem that existing phenolic gaskets cannot meet the higher requirements of modern aviation transportation on material properties.

[0005] The present invention provides a phenolic gasket used for an aircraft fuel tank cover structural connector, comprising a phenolic resin layer and a protective coating, wherein the phenolic resin layer and the protective coating are tightly bonded, and the protective coating comprises a polytetrafluoroethylene layer and / or a polyurethane layer.

[0006] Furthermore, the phenolic gasket also includes an epoxy resin layer, one end of the epoxy resin layer is tightly bonded to the phenolic resin layer, and the other end of the epoxy resin layer is tightly bonded to the protective coating.

[0007] Furthermore, the thickness of the epoxy resin layer is 30 to 50 microns.

[0008] Furthermore, the polytetrafluoroethylene layer and the epoxy resin layer are sequentially arranged on the upper surface of the phenolic resin layer from top to bottom, the polyurethane layer, the polytetrafluoroethylene layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer, the polytetrafluoroethylene layer and the polyurethane layer are sequentially arranged on the right side of the phenolic resin layer from left to right.

[0009] Furthermore, the polytetrafluoroethylene layer and the epoxy resin layer are sequentially arranged on the upper surface of the phenolic resin layer from top to bottom, the polyurethane layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer and the polyurethane layer are sequentially arranged on the right side of the phenolic resin layer from left to right.

[0010] Furthermore, the polytetrafluoroethylene layer is disposed on the upper surface of the phenolic resin layer, the polyurethane layer and the epoxy resin layer are disposed sequentially from left to right on the left side of the phenolic resin layer, and the epoxy resin layer and the polyurethane layer are disposed sequentially from left to right on the right side of the phenolic resin layer.

[0011] Furthermore, the thickness of the polytetrafluoroethylene layer is 30 to 50 microns, and the thickness of the polyurethane layer is 30 to 50 microns.

[0012] Furthermore, the polyurethane layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer and the polyurethane layer are sequentially arranged on the right side of the phenolic resin layer from left to right.

[0013] Furthermore, the polytetrafluoroethylene layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer and the polytetrafluoroethylene layer are sequentially arranged on the right side of the phenolic resin layer from left to right.

[0014] Furthermore, the thickness of the phenolic resin layer is 0.5 mm, and the width of the phenolic resin layer is 5 mm.

[0015] The present invention also proposes a method for manufacturing the phenolic gasket used for the aircraft fuel tank cover structural connector as described above, the manufacturing method comprising the following steps:

[0016] S1, using a shot blasting process and a sand blasting process to treat the surface to be coated of the phenolic resin layer, so that the roughness of the surface to be coated is 30 to 50 microns and the flatness is less than or equal to 2 mm;

[0017] S2. If it is confirmed that polytetrafluoroethylene needs to be coated, polytetrafluoroethylene is coated on the surface to be coated by a spraying process or a dipping process to form a polytetrafluoroethylene layer; wherein the coating thickness of the polytetrafluoroethylene layer is 30 to 50 microns;

[0018] S3. If it is confirmed that polyurethane needs to be coated, the polyurethane is coated on the surface to be coated by a spraying process to form a polyurethane layer; wherein the thickness of the polyurethane layer is 30 to 50 microns;

[0019] S4, curing the applied coating.

[0020] Furthermore, after S1, the step further includes:

[0021] S11. Use a spraying process to coat epoxy resin on the surface to be coated to form an epoxy resin layer; wherein the coating thickness of the epoxy resin layer is 30 to 50 microns.

[0022] Further, the S4 includes: performing three curing treatments on the applied coating, the curing temperature of the three curing treatments is 5-35°C, and the curing time of each coating is 24 hours.

[0023] Compared with the prior art, the beneficial effects of the present invention are: a phenolic gasket used for an aircraft fuel tank cover structural connector and a method for making the same, comprising a phenolic resin layer and a protective coating, wherein the phenolic resin layer and the protective coating are tightly bonded, and the protective coating comprises a polytetrafluoroethylene layer and / or a polyurethane layer. The polytetrafluoroethylene layer can provide excellent wear resistance and solvent resistance, while the polyurethane layer can enhance moisture resistance, anti-mildew and electrical isolation functions. Tightly bonding the polytetrafluoroethylene layer and / or the polyurethane layer to the phenolic resin layer to form a new phenolic gasket with a composite structure can combine the multiple advantages of the protective coating to provide more comprehensive protection for the phenolic gasket, thereby significantly improving its performance and meeting the strict requirements of modern aviation transportation on material properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0025] Figure 1 A schematic diagram of the structure of a phenolic gasket applied to a structural connector of an aircraft fuel tank cover provided by an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A cross-sectional view of the AA surface of a phenolic gasket used in a structural connector of an aircraft fuel tank cover;

[0027] Figure 3 for Figure 2 Schematic diagram of the structure of the local A in the middle;

[0028] Figure 4 A schematic flow chart of a method for manufacturing a phenolic gasket used in a structural connector of an aircraft fuel tank cover provided in an embodiment of the present invention.

[0029] Description of Figure Numbers:

[0030] 10-phenolic resin layer, 20-polytetrafluoroethylene layer, 30-polyurethane layer, 40-epoxy resin layer. DETAILED DESCRIPTION

[0031] The scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] It should be noted that polytetrafluoroethylene (PTFE) is a high-performance fluoropolymer that has excellent tolerance to almost all chemicals and can resist corrosive substances such as acids, alkalis and solvents. Polytetrafluoroethylene has a wide operating temperature range and can usually be used between -200°C and 260°C, which is suitable for high temperature environments. In addition, it also has an extremely low coefficient of friction and is often used as a coating for industrial equipment. The phenolic gasket used in the aircraft fuel tank cover structural connector provided in an embodiment of the present invention is a polytetrafluoroethylene varnish, which is a weather-resistant fluororesin paint cured by fluororesin and non-yellowing isocyanate.

[0035] Polyurethane (PU) is a multifunctional polymer with excellent elasticity and flexibility, and is suitable for use in situations where deformation is required. At the same time, its wear resistance makes it suitable for use in high-wear environments. In addition, polyurethane also has good moisture resistance and mildew resistance, can effectively resist moisture intrusion, and is suitable for use in humid environments. The phenolic gasket used in the aircraft fuel tank cover structural connector provided in the embodiment of the present invention is PU8100 acrylic polyurethane varnish, which is a two-component low-viscosity transparent varnish.

[0036] Epoxy resin (EP) is a thermosetting resin that can form strong bonds with a variety of materials and is suitable for use in chemical environments. The cured epoxy resin has good heat resistance and high mechanical strength, and is suitable for high temperature and structural applications. The phenolic gasket used in the aircraft fuel tank cover structural connector provided in the embodiment of the present invention uses ED1400 epoxy sealing primer, which is a two-component low-viscosity epoxy coating.

[0037] The protective coating is mainly processed using a spraying process and an impregnation process so as to form a close bonding relationship with the phenolic resin layer 10. Among them, the spraying process is a method of evenly spraying the coating onto the target surface through a spray gun or a spray device. This process has the characteristics of strong uniformity, wide adaptability and high efficiency. It can complete large-area coating in a short time and is suitable for industrial production. The thickness of the spraying is controllable, and different performance requirements can be met by adjusting the spraying speed and nozzle settings. The impregnation process is to completely immerse the object to be treated in the coating so that a coating is formed on its surface. This process can achieve deep penetration, ensure that the coating evenly covers the object, and provide better adhesion and protection effects.

[0038] Please refer to Figure 1-3 As shown, the present invention proposes a phenolic gasket used for an aircraft fuel tank cover structural connector, comprising a phenolic resin layer 10 and a protective coating, wherein the phenolic resin layer 10 and the protective coating are tightly bonded, and the protective coating comprises a polytetrafluoroethylene layer 20 and / or a polyurethane layer 30.

[0039] Specifically, in order to adapt to different types of aircraft fuel tank structures on the market, aircraft fuel tank cover structure connectors have various shapes. In order to adapt to various shapes of aircraft fuel tank cover structure connectors, it is necessary to design phenolic gaskets in various shapes. The more common phenolic gaskets on the market are generally in the shape of a circular ring, an elliptical ring ( Figure 1 The phenolic gasket described in the invention is an elliptical ring) or a runway ring (a runway ring refers to a circle or an ellipse around the center line of the runway), etc. Installing the phenolic gasket on the matching aircraft fuel tank cap structural connector can effectively enhance the tightness and stability between the aircraft fuel tank cap maintenance cover and the aircraft fuel tank pressure ring.

[0040] Specifically, the traditional wear-resistant phenolic gasket is a high-performance wear-resistant material layer made of phenolic resin, which is mainly used in aircraft fuel tank cover structural connectors. The phenolic gasket used for aircraft fuel tank cover structural connectors provided in the embodiment of the present invention is a traditional wear-resistant phenolic gasket with a protective coating added. Because the working environment of the phenolic gasket needs to be immersed in aviation fuel for a long time, and must cope with challenges such as high humidity, moisture, mildew, mechanical wear, and solvent erosion. Therefore, the added protective coating must not only have the characteristics of moisture resistance, humidity resistance, and mildew resistance, but also must ensure wear resistance, solvent resistance, aviation fuel (jet kerosene) resistance and other properties, and have a reinforcement effect and good electrical isolation function. The specific requirements are as follows:

[0041] 1. Wear resistance: Under long-term friction conditions, the protective coating must have high wear resistance to ensure the service life of the phenolic gasket.

[0042] 2. Moisture, humidity and mildew resistance: The working environment of phenolic gaskets involves high humidity and humid conditions. The protective coating needs to have excellent moisture and mildew resistance to prevent performance degradation.

[0043] 3. Solvent resistance: The protective coating must have solvent resistance to ensure that it will not be dissolved or stratified when immersed in aviation kerosene.

[0044] 4. Reinforcement and electrical isolation: The protective coating needs to have a reinforcement effect, enhance the overall structural strength of the phenolic gasket, and provide effective electrical isolation.

[0045] In order to meet the above requirements, the protective coating materials are selected from polytetrafluoroethylene and polyurethane. Polytetrafluoroethylene can provide excellent wear resistance and solvent resistance, while polyurethane can enhance moisture resistance, anti-fungus and electrical isolation functions. Single-layer protective coatings or composite protective coatings made of these two materials can give full play to the advantages of their own materials and provide more comprehensive protection for phenolic gaskets.

[0046] Compared with the prior art, the phenolic gasket used for the aircraft fuel tank cover structure connector provided in the embodiment of the present invention includes a phenolic resin layer 10 and a protective coating, wherein the protective coating includes a polytetrafluoroethylene layer 20 and / or a polyurethane layer 30. The polytetrafluoroethylene layer 20 can provide excellent wear resistance and solvent resistance, while the polyurethane layer 30 can enhance moisture resistance, anti-mildew and electrical isolation functions. The polytetrafluoroethylene layer 20 and / or the polyurethane layer 30 are tightly bonded to the phenolic resin layer 10 to form a new phenolic gasket with a composite structure, which can combine the multiple advantages of the protective coating to provide more comprehensive protection for the phenolic gasket, thereby significantly improving its performance, meeting the strict requirements of modern aviation transportation on material performance, and further improving the flight safety level of the aircraft.

[0047] In some embodiments of the present application, the phenolic gasket further includes an epoxy resin layer 40, one end of the epoxy resin layer 40 is tightly bonded to the phenolic resin layer 10, and the other end of the epoxy resin layer 40 is tightly bonded to the protective coating.

[0048] Specifically, epoxy resin (or epoxy resin primer) is an adhesive. Using the epoxy resin layer 40 as the bottom coating can improve the adhesion between the protective coating and the phenolic resin layer 10, and enhance the durability of the protective coating. The polytetrafluoroethylene layer 20 as the middle layer can provide wear resistance and solvent resistance protection for the phenolic gasket. The polyurethane layer 30 as the outer layer can further enhance the moisture resistance, mildew resistance and electrical isolation performance of the phenolic gasket.

[0049] In some embodiments of the present application, the epoxy resin layer 40 has a thickness of 30 to 50 micrometers.

[0050] Specifically, the thickness of the epoxy resin layer 40 may vary according to the shape characteristics of different aircraft fuel tank cover structural connectors. However, the coating thickness must be within a range of 30 to 50 microns to avoid the phenomenon that the aircraft fuel tank cover structural connector cannot be properly installed due to the thickness of the final phenolic gasket product being too thick.

[0051] It should be noted that the phenolic gasket used for the aircraft fuel tank cap structural connector provided in this embodiment is installed on the surface of the aircraft fuel tank cap maintenance cover, and an installation adhesive layer is provided on the installation contact surface between the two. In order not to affect the bonding effect of the installation adhesive layer, the installation adhesive surface (lower surface) of the phenolic gasket is not added with a protective coating (no protective coating treatment), and the protective coating is only added to at least one of the upper surface, left side surface and right side surface of the phenolic gasket.

[0052] The following are five different embodiments of phenolic gaskets used in aircraft fuel tank cover structural connectors provided by the present invention, corresponding to different phenolic gasket protective coating design schemes to meet different installation environments and performance requirements. Each embodiment has undergone rigorous quality inspection and adaptability testing to ensure excellent sealing and durability in practical applications. Of course, in the actual application process, other implementation plans can also be selected according to specific application requirements and installation environments, such as using protective coatings with different setting orders, adjusting the thickness of the protective coating, etc., to meet the ever-changing technical requirements and safety standards, and no further examples will be given here.

[0053] In some embodiments of the present application, the polytetrafluoroethylene layer 20 and the epoxy resin layer 40 are sequentially arranged on the upper surface of the phenolic resin layer 10 from top to bottom, the polyurethane layer 30, the polytetrafluoroethylene layer 20 and the epoxy resin layer 40 are sequentially arranged on the left side of the phenolic resin layer 10 from left to right, and the epoxy resin layer 40, the polytetrafluoroethylene layer 20 and the polyurethane layer 30 are sequentially arranged on the right side of the phenolic resin layer 10 from left to right. Figure 1 The structure diagram of the phenolic gasket applied to the aircraft fuel tank cover structural connector provided by this embodiment is shown in FIG.

[0054] Specifically, the phenolic gasket does not have a protective coating on the mounting bonding surface (lower surface) corresponding to the maintenance cover. The contact surface (upper surface) of the phenolic gasket and other connectors, such as a conductive gasket or a pressure ring, has a protective coating, which is a composite coating of an epoxy resin layer 40 + a polytetrafluoroethylene layer 20. The inner and outer ring cross-sections of the phenolic gasket also have a protective coating, which is a composite coating of an epoxy resin layer 40 + a polytetrafluoroethylene layer 20 + a polyurethane layer 30.

[0055] In some embodiments of the present application, the thickness of the polytetrafluoroethylene layer 20 is 30 to 50 microns, and the thickness of the polyurethane layer 30 is 30 to 50 microns.

[0056] Specifically, the thickness of the polytetrafluoroethylene layer 20 and the polyurethane layer 30 can be different according to the shape characteristics of different aircraft fuel tank cover structural connectors. However, the coating thickness must be within a range of 30 to 50 microns to avoid the phenomenon that the aircraft fuel tank cover structural connector cannot be properly installed due to the thickness of the final phenolic gasket product being too thick.

[0057] In some embodiments of the present application, the polytetrafluoroethylene layer 20 and the epoxy resin layer 40 are sequentially arranged on the upper surface of the phenolic resin layer 10 from top to bottom, the polyurethane layer 30 and the epoxy resin layer 40 are sequentially arranged on the left side of the phenolic resin layer 10 from left to right, and the epoxy resin layer 40 and the polyurethane layer 30 are sequentially arranged on the right side of the phenolic resin layer 10 from left to right.

[0058] Specifically, the phenolic gasket does not have a protective coating on the mounting bonding surface (lower surface) corresponding to the maintenance cover. The contact surface (upper surface) of the phenolic gasket and other connectors, such as a conductive gasket or a pressure ring, has a protective coating, which is a composite coating of an epoxy resin layer 40 + a polytetrafluoroethylene layer 20. The inner and outer ring cross-sections of the phenolic gasket also have a protective coating, which is a composite coating of an epoxy resin layer 40 + a polyurethane layer 30.

[0059] In some embodiments of the present application, the polytetrafluoroethylene layer 20 is disposed on the upper surface of the phenolic resin layer 10, the polyurethane layer 30 and the epoxy resin layer 40 are disposed on the left side of the phenolic resin layer 10 in sequence from left to right, and the epoxy resin layer 40 and the polyurethane layer 30 are disposed on the right side of the phenolic resin layer 10 in sequence from left to right.

[0060] Specifically, the phenolic gasket does not have a protective coating on the mounting bonding surface (lower surface) corresponding to the maintenance cover. The contact surface (upper surface) of the phenolic gasket and other connectors, such as a conductive gasket or a pressure ring, has a protective coating, which is a polytetrafluoroethylene layer 20. The inner and outer ring cross-sections of the phenolic gasket also have a protective coating, which is a composite coating of an epoxy resin layer 40 + a polyurethane layer 30.

[0061] In some embodiments of the present application, the polyurethane layer 30 and the epoxy resin layer 40 are sequentially arranged on the left side of the phenolic resin layer 10 from left to right, and the epoxy resin layer 40 and the polyurethane layer 30 are sequentially arranged on the right side of the phenolic resin layer 10 from left to right.

[0062] Specifically, the phenolic gasket has no protective coating on its mounting bonding surface (lower surface) corresponding to the maintenance cover. The contact surface (upper surface) between the phenolic gasket and other connectors, such as a conductive gasket or a pressure ring, has no protective coating. The inner and outer ring cross-sections of the phenolic gasket have a protective coating, which is a composite coating of an epoxy resin layer 40 + a polyurethane layer 30.

[0063] In some embodiments of the present application, the polytetrafluoroethylene layer 20 and the epoxy resin layer 40 are sequentially arranged on the left side of the phenolic resin layer 10 from left to right, and the epoxy resin layer 40 and the polytetrafluoroethylene layer 20 are sequentially arranged on the right side of the phenolic resin layer 10 from left to right.

[0064] Specifically, the phenolic gasket has no protective coating on its mounting bonding surface (lower surface) corresponding to the maintenance cover. The contact surface (upper surface) between the phenolic gasket and other connectors, such as a conductive gasket or a pressure ring, has no protective coating. The inner and outer ring cross-sections of the phenolic gasket have a protective coating, which is a composite coating of an epoxy resin layer 40 + a polytetrafluoroethylene layer 20.

[0065] In some embodiments of the present application, the thickness of the phenolic resin layer 10 is 0.5 mm, and the width of the phenolic resin layer 10 is 5 mm.

[0066] Specifically, the phenolic resin layer 10 has a thickness of 0.5 mm and a width of 5 mm. The roughness of the coated front side is 30 to 50 microns. The surface is required to be clean and free of oil stains, looseness, cracks, peeling, adherence of particles, etc., and the side is required to be free of burrs.

[0067] The following is an embodiment of the method for making a phenolic gasket applied to an aircraft fuel tank cap structural connector provided by the present invention. The embodiment of the method for making a phenolic gasket applied to an aircraft fuel tank cap structural connector belongs to the same concept as the above-mentioned embodiment of the phenolic gasket applied to an aircraft fuel tank cap structural connector. For details not described in detail in the embodiment of the method for making a phenolic gasket applied to an aircraft fuel tank cap structural connector, reference can be made to the above-mentioned embodiment of the phenolic gasket applied to an aircraft fuel tank cap structural connector.

[0068] Please refer to Figure 4 As shown, it is a schematic flow chart of a method for manufacturing a phenolic gasket applied to a structural connector of an aircraft fuel tank cover provided by an embodiment of the present invention.

[0069] The present invention also proposes a method for manufacturing the phenolic gasket used for the aircraft fuel tank cover structural connector as described above, the manufacturing method comprising the following steps:

[0070] S1, using a shot blasting process and a sand blasting process to perform surface treatment on the surface to be coated of the phenolic resin layer 10, so that the roughness of the surface to be coated is 30 to 50 microns and the flatness is less than or equal to 2 mm;

[0071] S2. If it is confirmed that polytetrafluoroethylene needs to be coated, polytetrafluoroethylene is coated on the surface to be coated by a spraying process or a dipping process to form a polytetrafluoroethylene layer 20; wherein the coating thickness of the polytetrafluoroethylene layer 20 is 30 to 50 microns;

[0072] S3, if it is confirmed that polyurethane coating is required, then the polyurethane is coated on the surface to be coated by a spraying process to form a polyurethane layer 30; wherein the thickness of the polyurethane layer 30 is 30 to 50 microns;

[0073] S4, curing the applied coating.

[0074] It should be noted that there is no particular order between step S2 and step S3, and both can be implemented simultaneously, at the same time, or repeatedly. In actual application, the order and number of implementations can be selected according to specific design requirements.

[0075] Specifically, the shot blasting process is to achieve surface treatment by spraying steel shot or other granular materials at high speed onto the surface to be treated through a high-speed rotating shot blasting machine. Its main uses include removing surface dirt and oxides, enhancing surface strength, improving coating adhesion, and adjusting surface finish. The shot blasting process is highly efficient and can evenly treat workpieces of complex shapes, making it suitable for large-scale production.

[0076] Sandblasting is a process in which sand or other abrasives are sprayed at high pressure through a nozzle onto the surface to be processed. It is mainly used to clean, roughen and trim the surface. Its main uses include removing oxides, rust and old coatings on the surface, increasing surface roughness to improve coating adhesion, and removing burrs generated during processing. Sandblasting can adjust the surface effect according to different abrasives and spraying pressures. It has a relatively low cost and a wide range of applications.

[0077] In some embodiments of the present application, the step S1 further includes:

[0078] S11, coating the surface to be coated with epoxy resin using a spraying process to form an epoxy resin layer 40; wherein the coating thickness of the epoxy resin layer 40 is 30 to 50 microns.

[0079] In some embodiments of the present application, S4 includes: performing three curing treatments on the applied coating, the curing temperature of the three curing treatments is 5-35° C., and the curing time of each coating is 24 hours.

[0080] The following details the specific steps of the method for making a phenolic gasket used in a structural connector of an aircraft fuel tank cover:

[0081] 1. Surface treatment: Clean and roughen the surface of the traditional wear-resistant phenolic gasket to ensure the adhesion of the coating. The surface treatment equipment is a sandblasting machine or other roughening equipment.

[0082] 2. Primer spraying: Use epoxy resin primer to spray the bottom layer to ensure even coverage.

[0083] 3. Intermediate layer coating: Use spraying or dipping process to coat PTFE and control the thickness and uniformity of the intermediate coating.

[0084] 4. External coating: The polyurethane coating is applied by spraying process to ensure the integrity and adhesion of the external coating. Among them, the spraying equipment is suitable for epoxy resin, polytetrafluoroethylene and polyurethane materials.

[0085] 5. Curing: Curing the applied coating under appropriate temperature and humidity conditions to ensure the physical properties of the coating. The curing equipment is a curing oven with temperature and humidity control functions.

[0086] For the phenolic gaskets manufactured using this production method, quality inspection and environmental adaptability tests are also required, including:

[0087] Quality testing includes:

[0088] 1. Coating thickness detection: Use a film thickness meter to perform online detection of the thickness of the protective coating and epoxy resin layer 40 to ensure that the thickness of each layer meets the design standard.

[0089] 2. Adhesion test: The cross-hatch method is used to test the adhesion between the protective coating and the epoxy resin layer 40 and the phenolic resin layer 10 (substrate).

[0090] 3. Wear resistance test: Use an abrasion tester to perform a wear resistance test on the polytetrafluoroethylene layer 20 to ensure the durability of the polytetrafluoroethylene layer 20.

[0091] Environmental adaptability test:

[0092] 1. Moisture resistance test: The phenolic gaskets are subjected to constant humidity and heat tests under high humidity conditions to ensure their moisture resistance.

[0093] 2. Mildew resistance test: The phenolic gaskets produced are subjected to mildew tests according to relevant standards to verify the mildew resistance.

[0094] 3. Solvent resistance test: The phenolic gaskets were immersed in kerosene to evaluate the solvent resistance of the protective coating.

[0095] The test results show that the phenolic gaskets manufactured using this production method significantly improve the environmental adaptability and durability of traditional phenolic gaskets. Through excellent wear resistance, solvent resistance and electrical isolation properties, they ensure the stable and safe operation of the aircraft fuel system, meet the strict requirements of modern air transportation on material properties, further improve the flight safety level of the aircraft, and provide more reliable protection for the safety of pilots and passengers.

[0096] The method for manufacturing a phenolic gasket applied to an aircraft fuel tank cover structural connector provided by an embodiment of the present invention has the same concept as the embodiment of the phenolic gasket applied to an aircraft fuel tank cover structural connector described above, and therefore has at least all the beneficial effects brought about by the embodiment of the phenolic gasket applied to an aircraft fuel tank cover structural connector described above, and thus will not be described in detail here.

[0097] It should be noted that the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0098] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A phenolic gasket used in a structural connector of an aircraft fuel tank cover, characterized in that: The invention comprises a phenolic resin layer and a protective coating layer, wherein the phenolic resin layer and the protective coating layer are tightly bonded, and the protective coating layer comprises a polytetrafluoroethylene layer and / or a polyurethane layer.

2. The phenolic gasket used for aircraft fuel tank cover structural connector according to claim 1, characterized in that: The phenolic gasket further comprises an epoxy resin layer, one end of the epoxy resin layer is tightly bonded to the phenolic resin layer, and the other end of the epoxy resin layer is tightly bonded to the protective coating layer.

3. The phenolic gasket used for the aircraft fuel tank cover structural connector according to claim 2, characterized in that: The thickness of the epoxy resin layer is 30 to 50 microns.

4. The phenolic gasket used for the aircraft fuel tank cover structural connector according to claim 2, characterized in that: The polytetrafluoroethylene layer and the epoxy resin layer are arranged in sequence from top to bottom on the upper surface of the phenolic resin layer, the polyurethane layer, the polytetrafluoroethylene layer and the epoxy resin layer are arranged in sequence from left to right on the left side of the phenolic resin layer, and the epoxy resin layer, the polytetrafluoroethylene layer and the polyurethane layer are arranged in sequence from left to right on the right side of the phenolic resin layer; or The polytetrafluoroethylene layer and the epoxy resin layer are arranged in sequence from top to bottom on the upper surface of the phenolic resin layer, the polyurethane layer and the epoxy resin layer are arranged in sequence from left to right on the left side of the phenolic resin layer, and the epoxy resin layer and the polyurethane layer are arranged in sequence from left to right on the right side of the phenolic resin layer; or The polytetrafluoroethylene layer is arranged on the upper surface of the phenolic resin layer, the polyurethane layer and the epoxy resin layer are arranged in sequence from left to right on the left side of the phenolic resin layer, and the epoxy resin layer and the polyurethane layer are arranged in sequence from left to right on the right side of the phenolic resin layer.

5. The phenolic gasket used for aircraft fuel tank cover structural connector according to claim 4, characterized in that: The thickness of the polytetrafluoroethylene layer is 30 to 50 microns, and the thickness of the polyurethane layer is 30 to 50 microns.

6. The phenolic gasket used for the aircraft fuel tank cover structural connector according to claim 2, characterized in that: The polyurethane layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer and the polyurethane layer are sequentially arranged on the right side of the phenolic resin layer from left to right; or The polytetrafluoroethylene layer and the epoxy resin layer are sequentially arranged on the left side of the phenolic resin layer from left to right, and the epoxy resin layer and the polytetrafluoroethylene layer are sequentially arranged on the right side of the phenolic resin layer from left to right.

7. The phenolic gasket used for aircraft fuel tank cover structural connector according to claim 1, characterized in that: The thickness of the phenolic resin layer is 0.5 mm, and the width of the phenolic resin layer is 5 mm.

8. A method for manufacturing a phenolic gasket used for a structural connector of an aircraft fuel tank cover as claimed in any one of claims 1 to 7, characterized in that: The production method comprises the following steps: S1, using a shot blasting process and a sand blasting process to treat the surface to be coated of the phenolic resin layer, so that the roughness of the surface to be coated is 30 to 50 microns and the flatness is less than or equal to 2 mm; S2. If it is confirmed that polytetrafluoroethylene needs to be coated, polytetrafluoroethylene is coated on the surface to be coated by a spraying process or a dipping process to form a polytetrafluoroethylene layer; wherein the coating thickness of the polytetrafluoroethylene layer is 30 to 50 microns; S3. If it is confirmed that polyurethane needs to be coated, the polyurethane is coated on the surface to be coated by a spraying process to form a polyurethane layer; wherein the thickness of the polyurethane layer is 30 to 50 microns; S4, curing the applied coating.

9. The method for manufacturing a phenolic gasket used for a structural connector of an aircraft fuel tank cover according to claim 8, characterized in that: The S1 also includes: S11. Use a spraying process to coat epoxy resin on the surface to be coated to form an epoxy resin layer; wherein the coating thickness of the epoxy resin layer is 30 to 50 microns.

10. The method for manufacturing a phenolic gasket used for a structural connector of an aircraft fuel tank cover according to claim 8, characterized in that: The step S4 includes: performing three curing treatments on the applied coating, wherein the curing temperature of the three curing treatments is 5 to 35° C., and the curing time of each coating is 24 hours.

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