Integrated board with wave absorbing performance and forming process method thereof

Abstract

The invention discloses an integrated board with wave absorbing performance and a forming process method thereof.The integrated board comprises a carbon fiber skeleton, a skeleton partition frame is formed in the carbon fiber skeleton, a polyurethane foam board is arranged in the skeleton partition frame, a steel plate and a stealth board are arranged on the outer side of the carbon fiber skeleton, and the steel plate is arranged between the carbon fiber skeleton and the stealth board; a carbon fiber inner skin is arranged on the inner side of the carbon fiber skeleton; the forming process method comprises the following steps: preparing the invisible plate; the preparation method comprises the following steps: preparing a mold, sequentially laying demolding cloth, a stealth plate, a steel plate and a carbon fiber skeleton in the mold, placing a polyurethane foam plate in a skeleton bulkhead, laying carbon fiber cloth on the polyurethane foam plate, laying the demolding cloth on the polyurethane foam plate, laying a flow guide net, packaging a vacuum bag film, introducing a resin glue solution under vacuum negative pressure, curing, demolding, and polishing the appearance, so as to obtain the stealth plate. The integrated board with the wave absorbing performance is obtained. According to the invention, expensive wave-absorbing paint is not needed, and the prepared integrated board has ultrahigh strength and good wave-absorbing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of cabin panels, and more particularly to an integrated panel with wave-absorbing properties and a forming method thereof. Background Art

[0002] In military applications, the stealth performance of shelters is crucial, as they need to minimize the risk of being detected by enemy radar on the battlefield and improve their survivability. Traditional shelter panels are not stealthy to radar detection and cannot meet the high stealth requirements of modern military.

[0003] In order to achieve a stealth effect, the existing technology improves the product's absorbing performance by directly spraying absorbing paint on the exposed surface outside the cabin. However, absorbing paint is usually expensive, the raw material cost cycle is too long, and the paint's absorbing performance is affected by the workplace, workers' operating techniques, and proportions, which can lead to instability. In addition, the existing cabin structure also has the problem of low strength. Summary of the Invention

[0004] In view of this, one of the objects of the present invention is to provide a molding process method for an integrated panel with absorbing performance. The process method provided by the present invention does not require the use of expensive absorbing coatings. The prepared stealth panel can be directly set on the outside of the cabin. It not only has absorbing performance but also can serve as a structural layer to improve the overall structural performance. By changing the cabin panel structure, the exposed layer outside the cabin meets the performance requirements to reduce the high cost of absorbing coatings, and the prepared integrated panel has high strength.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A molding process for an integrated panel with wave-absorbing properties, the integrated panel comprising a carbon fiber skeleton, a skeleton bulkhead formed within the carbon fiber skeleton, a polyurethane foam panel disposed within the skeleton bulkhead, a steel plate and a stealth panel disposed on the outer side of the carbon fiber skeleton, the steel plate disposed between the carbon fiber skeleton and the stealth panel, and a carbon fiber inner skin disposed on the inner side of the carbon fiber skeleton;

[0007] The molding process comprises the following steps:

[0008] S1. Preparation of single-layer absorbing plate

[0009] Apply adhesive on the resistor film, then lay the resistor film coated with adhesive on the PMI foam, and solidify it to obtain a single-layer absorbing board;

[0010] S2. Performing a performance test on the single-layer absorbing panels, performing a numbering process, and then laser engraving the numbered single-layer absorbing panels;

[0011] S3, repeating steps S1-S2 to prepare multiple single-layer absorbing panels, stacking the multiple single-layer absorbing panels one above the other, and bonding and curing them with an adhesive to obtain a multi-layer absorbing panel;

[0012] S4, cutting and punching the obtained multi-layer absorbing plate;

[0013] S5. Fixing the inner skin and the outer skin to the inner side and the outer side of the multi-layer absorbing plate respectively;

[0014] S6, obtaining the stealth plate after cutting, modifying and inspecting;

[0015] S7. Prepare a mold, lay the demoulding cloth, the stealth plate, the steel plate, and the carbon fiber skeleton in the mold in sequence, place a polyurethane foam board in the skeleton frame of the carbon fiber skeleton, and then lay the carbon fiber cloth used to form the carbon fiber inner skin on the polyurethane foam board, lay the demoulding cloth on the polyurethane foam board, and then lay the guide net, encapsulate the vacuum bag film, and introduce the resin glue under vacuum negative pressure. After curing, demoulding, and polishing the appearance, an integrated board with wave-absorbing performance is obtained.

[0016] Furthermore, in step S1, the adhesive is obtained by mixing an epoxy resin and a curing agent, and the mixing ratio of the epoxy resin to the curing agent is 1:1-1.5;

[0017] After the resistor film is laid on the PMI foam, it is placed on a press within 30 minutes for room temperature pressurization and curing; the curing time is 20-30 hours.

[0018] Furthermore, in step S2, the performance test includes testing the sheet resistance of three points on the left, middle and right sides of the single-layer absorbing plate using a sheet resistance tester to evaluate the resistance uniformity of the single-layer absorbing plate.

[0019] Furthermore, in step S3, curing is specifically performed by placing the stacked multiple single-layer absorbing panels on a press and curing them under pressure at room temperature for 20-30 hours.

[0020] Furthermore, in step S4, the cutting is specifically performed by milling with an engraving machine, and the processed multi-layer absorbing plate has a length of 800-1200 mm, a width of 400-600 mm, and a thickness of 20-40 mm; the punching is specifically performed by using a punching template drill, the hole diameter is 1.5-3 mm, and the hole spacing is 20-40 mm.

[0021] Furthermore, in step S5, the outer skin is formed by vacuum bagging quartz fiber;

[0022] The inner skin is obtained by vacuum bagging carbon fibers;

[0023] Lay the outer skin, the punched multi-layer absorbing plate and the inner skin in the mold frame. Before laying, apply epoxy resin between the layers to ensure that the resin is sufficient and uniform everywhere. Use quartz fiber cloth for edge and corner wrapping, and use vacuum bag pressing to form the inner skin, outer skin and the multi-layer absorbing plate into one piece.

[0024] Furthermore, step S7 also includes pre-laying the stealth panel, carbon fiber skeleton and polyurethane foam panel in the mold.

[0025] A second object of the present invention is to provide an integrated board with wave-absorbing properties obtained by any of the above-mentioned molding process methods.

[0026] Another object of the present invention is to provide a shelter comprising the integrated panel described above.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The molding process provided by the present invention is to obtain a single-layer absorbing plate by applying an adhesive to a resistive film and then pressing and curing it with PMI foam. Then, multiple single-layer absorbing plates are stacked in sequence, bonded and cured, and further cut and punched, and then vacuum-bag-assisted molding is performed with the inner and outer skins. The prepared stealth plate can be directly set on the outside of the cabin body, not only having absorbing properties but also serving as a structural layer to improve the overall structural performance. By changing the cabin plate structure, the exposed layer outside the cabin can meet the performance requirements, thereby reducing the high cost of absorbing coatings.

[0029] A layer of ultra-strength steel plate of corresponding thickness is placed between the stealth panel and the carbon fiber frame, which can ensure that the ultra-strength requirements are met while absorbing waves.

[0030] In the present invention, the ultra-strength integrated board is formed in a mold through a vacuum-assisted molding process, and the integrated board prepared has improved flatness and density of the inner surface of the cabin board, thereby improving the overall strength of the cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of the structural composition of the stealth plate in the present invention.

[0033] Figure 2 It is a structural schematic diagram of the integrated board in the present invention.

[0034] Description of reference numerals:

[0035] 1. Stealth panel; 2. Carbon fiber frame; 3. Frame bulkhead; 4. Polyurethane foam; 5. Carbon fiber inner skin; 6. Steel plate. DETAILED DESCRIPTION

[0036] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0038] The present invention will be explained and described in detail below with reference to the accompanying drawings.

[0039] This embodiment specifically discloses a molding process method of an integrated board with wave absorbing performance, such as Figure 2 As shown, the integrated panel includes a carbon fiber skeleton 2, a skeleton bulkhead 3 is formed in the carbon fiber skeleton 2, a polyurethane foam board 4 is provided in the skeleton bulkhead 3, a steel plate 6 and a stealth board 1 are provided on the outside of the carbon fiber skeleton 2, the steel plate 6 is provided between the carbon fiber skeleton 2 and the stealth board 1, and a carbon fiber inner skin 5 is provided on the inside of the carbon fiber skeleton 2;

[0040] The molding process specifically includes the following steps:

[0041] S1. Preparation of single-layer absorbing plate

[0042] Apply adhesive to the resistor film, then lay the adhesive-coated resistor film on the PMI foam. After curing and forming, a single-layer absorbing board, i.e., a single board, is obtained. Each single board is composed of a PMI foam layer and a resistor film layer with adhesive cured on it. The PMI foam layer is the foam layer, and the resistor film layer is the absorbing layer.

[0043] Optionally, the adhesive is obtained by mixing an epoxy resin and a curing agent, wherein the mixing ratio of the epoxy resin to the curing agent is 1:1-1.5, wherein the epoxy resin is specifically epoxy resin E51; and the adhesive after being evenly mixed should not be wavy or delaminated.

[0044] Among them, PMI foam, or polymethacrylimide foam, is a lightweight, closed-cell rigid foam plastic. Based on a copolymer of methacrylic acid (MAA) and methacrylonitrile (MAN), it exhibits excellent mechanical properties, heat distortion temperature, and chemical stability, making it an ideal core material for high-performance sandwich composites.

[0045] In this embodiment, the PMI foam board serves as a lightweight, high-strength core material, the resistive film provides the wave absorption function (i.e., serves as the absorbing layer), and the epoxy resin and curing agent serve as the adhesive. The resistive film can have a specific square resistance, such as 50-200Ω / square. The resistive film can be made of a copper alloy (with trace amounts of nickel, chromium, and other elements added), a conductive polymer (such as polyaniline), or a carbon-based composite material. To improve adhesion, the PMI foam can be pre-treated with plasma, such as by introducing hydroxyl or carbonyl groups on the surface to enhance adhesion.

[0046] When applying the adhesive on the resistor film, an automatic scraper can be used to ensure uniform adhesive thickness. After the resistor film and PMI foam are laid flat and aligned, they can be pressed with a roller press to remove bubbles and avoid defects such as wrinkles and bubbles.

[0047] After the resistive film is laid onto the PMI foam, it must be placed on a roller press within 30 minutes for room-temperature pressurization and curing. Curing takes 20-30 hours, preferably 24 hours, to ensure complete curing of the adhesive. In some other embodiments, elevated temperature curing may also be used, depending on the type of adhesive.

[0048] Optionally, in some embodiments, in order to increase the absorption of low-frequency electromagnetic waves by the single board, a small amount of magnetic nanoparticles such as Fe3O4@SiO2 can be added to the adhesive, so that the prepared single board is more conducive to the absorption of low-frequency electromagnetic waves.

[0049] Specifically, Fe3O4@SiO2 magnetic nanoparticles possess unique magnetic properties. Under the influence of low-frequency electromagnetic waves, the magnetic domains within them rotate and their magnetization intensity changes, generating hysteresis losses. Simultaneously, the movement of electrons within the magnetic particles also generates eddy current losses due to factors such as scattering. These magnetic loss mechanisms effectively convert the energy of low-frequency electromagnetic waves into other forms of energy, such as heat, thereby enhancing their absorption.

[0050] Furthermore, interfaces exist between Fe3O4@SiO2 nanoparticles. Under the influence of the electric field of low-frequency electromagnetic waves, charge accumulates at the interface due to the different dielectric constants and electrical conductivity of the Fe3O4@SiO2, forming interfacial polarization. This interfacial polarization leads to loss of electric field energy, thereby increasing the absorption of low-frequency electromagnetic waves. Furthermore, the small size of the nanoparticles results in a relatively large interfacial area, making the interfacial polarization effect more significant, which is beneficial for improving low-frequency electromagnetic wave absorption performance.

[0051] After a single-layer absorbing plate is prepared, the next step can be performed.

[0052] S2. Testing the performance of the single-layer absorbing plate and numbering it, and then laser engraving the numbered single-layer absorbing plate to engrave an absorbing pattern;

[0053] Specifically, the performance test includes testing the square resistance of the single-layer absorbing board at three points, namely the left side, the middle and the right side, using a square resistance tester to evaluate the resistance uniformity and the absorbing performance of the single-layer absorbing board. Of course, in some other embodiments, its mechanical properties can also be tested. For single boards that fail the test, they are isolated and the reasons, such as uneven glue coating, insufficient curing, etc., can be analyzed for subsequent adjustments.

[0054] In addition, for different square resistance values, different laser parameters such as power, speed, frequency, etc. need to be selected during subsequent laser engraving to ensure the engraving effect; wherein, optionally, the absorbing pattern can be one or more of a rectangular lattice pattern, a circular lattice pattern, or a hexagonal lattice pattern.

[0055] In this embodiment, the square resistance of the three points on the left, middle and right is tested with a square resistance tester and recorded according to the number (the square resistance value and other performance parameters such as thickness are recorded to facilitate stacking as needed during subsequent bonding); the numbered single boards to be engraved are placed in the laser engraving area, the height between the laser head and the single board surface is controlled, and different programs are selected for laser engraving patterns for single boards with different square resistances; the engraved single boards are dusted and blown, and then they are placed in order on shelves with fixed numbers for use.

[0056] S3, repeating steps S1-S2 to prepare multiple single-layer absorbing panels, stacking the multiple single-layer absorbing panels one above the other, and bonding and curing them with an adhesive to obtain a multi-layer absorbing panel;

[0057] That is, according to the above steps S1 and S2, multiple single boards can be prepared. Of course, each single board can be set to a different thickness as needed. The thickness of the PMI foam in each single board can be different, and the thickness of the resistor film can also be set in a gradient.

[0058] Optionally, during curing, the stacked single-layer absorbing panels are placed on a press and cured under pressure at room temperature for 20-30 hours, preferably 24 hours, to ensure that the multi-layer absorbing panels are firmly bonded. During bonding, it is also necessary to avoid the generation of bubbles between the layers.

[0059] Specific, combined Figure 1 As shown, in this embodiment, a total of nine layers of single boards are bonded and cured to form a multi-layer absorbing board. In other embodiments, the number of layers can be adjusted based on the required thickness and performance, and is not specifically limited here. From the outside inward, the thickness of the absorbing layer in each single board can be gradually reduced, such as the outermost absorbing layer being 0.8-1.0 mm thick, gradually decreasing to approximately 0.05 mm at the innermost layer. This gradual change in interlayer impedance achieves broadband absorption, thereby enhancing its absorbing effect. When electromagnetic waves are emitted from the outside into the multi-layer absorbing board, the outer layer's resistive film is thinner and has a larger square resistance. Its surface impedance is relatively high, closer to the wave impedance of free space, facilitating the entry of electromagnetic waves. As the electromagnetic waves propagate into the absorbing board, the inner layer's resistive film gradually becomes thinner and its square resistance gradually increases. This gradually changes the internal impedance of the absorbing board, matching the characteristic impedance change of the electromagnetic wave as it propagates within the board. This allows the electromagnetic wave to penetrate deeper into the board, reducing reflection between layers.

[0060] Furthermore, from the outside to the inside, the thickness of the foam layer in the first layer of veneer is 2.5-3mm, the thickness of the foam layer in the second layer is 3.5-4.0mm, the thickness of the foam layer in the third layer is 2.5-3mm, the thickness of the foam layer in the fourth layer is 3.5-4.0mm, the thickness of the foam layer in the fifth layer is 3.0-3.5mm, the thickness of the foam layer in the sixth layer is 4.5-5.0mm; the thickness of the foam layer in the seventh layer is 1.5-2.0mm; the thickness of the foam layer in the eighth layer is 0.5-1.0mm, and the thickness of the foam layer in the ninth layer is 5-8mm.

[0061] In this embodiment, the combination of foam layers and absorbing layers of varying thickness enables the multi-layer absorbing panel to achieve superior absorbing performance across multiple frequency bands. The foam layer possesses specific electromagnetic properties (its internal void structure scatters electromagnetic waves, and the void walls and the air within the voids form interfaces between different media. Electromagnetic waves can be reflected, refracted, and scattered at these interfaces, complicating the propagation path and consuming the wave energy). Varying thickness influences the propagation and reflection of electromagnetic waves within the foam layer. Working synergistically with the absorbing layer, the foam layer can reflect, scatter, and absorb electromagnetic waves of varying frequencies multiple times, thereby broadening the absorbing frequency band, improving the absorption efficiency of electromagnetic waves of various frequencies, and enhancing the overall absorbing performance of the absorbing panel.

[0062] Optionally, in some other embodiments, parameters such as the number and thickness of the single panels may be adjusted according to the absorbing performance and the required thickness of the multi-layer absorbing panel as a whole.

[0063] In addition, it should be noted that when bonding the single panels in sequence, the amount of adhesive must be controlled to ensure that the thickness of the adhesive between each layer is less than 1 mm, preferably 0.3-0.8 mm. When the adhesive thickness is within this range, sufficient adhesion can be formed between the single-layer absorbing panels to ensure that the multi-layer absorbing panels can be firmly combined together to withstand the influence of various external forces and environmental factors during use without easily delaminating or falling off. At the same time, excessive adhesive thickness usually changes the overall electromagnetic properties of the absorbing panel, affecting the absorbing effect. By controlling the thickness between 0.3-0.8 mm, the negative impact of the adhesive on the absorbing performance can be reduced to a lower level. This thickness setting not only facilitates the uniform application of adhesive during construction, but also better controls the gap when assembling the multi-layer absorbing panels, avoiding excessive adhesive overflow or uneven surface of the absorbing panel due to uneven thickness, which affects the overall performance and appearance.

[0064] S4, cutting and punching the obtained multi-layer absorbing plate;

[0065] In this embodiment, the cutting process is performed using a milling machine. The resulting multi-layer absorbing panel has a length of 800-1200 mm, a width of 400-600 mm, and a thickness of 20-40 mm. The punching process is performed using a template drill, with holes having a diameter of 1.5-3 mm and a spacing of 20-40 mm. Using precise cutting tools ensures that the cut dimensions meet design requirements. Punching the multi-layer absorbing panel improves the subsequent bonding strength between the panel and the inner and outer skins.

[0066] S5. Fixing the inner skin and the outer skin to the inner side and the outer side of the multi-layer absorbing plate respectively;

[0067] In this embodiment, the outer skin is obtained by vacuum bagging quartz fiber;

[0068] The inner skin is obtained by vacuum bagging carbon fibers;

[0069] Lay the outer skin, the punched multi-layer absorbing plate, and the inner skin in the mold frame. Before laying, apply epoxy resin between the layers to ensure that the resin is sufficient and uniform everywhere. Use quartz fiber cloth to wrap the edges and corners to ensure that the edges are neat and beautiful. Use vacuum bag pressing to form the inner skin, outer skin and the multi-layer absorbing plate into one piece.

[0070] Similarly, during molding, the temperature can be controlled at 40°C for 3 hours, then raised to 70°C for 8 hours for curing. The lower temperature allows adhesives such as resins to begin to cure slowly. During this stage, the resin molecules begin to cross-link, but the reaction rate is relatively slow. This allows the adhesive enough time to fully penetrate and diffuse between the inner and outer skins and the multi-layer absorbing panels, filling tiny gaps and pores, which helps improve the bonding effect. At this temperature, it can also help release internal stress that may be generated during the molding process. Furthermore, raising the temperature to 70°C can accelerate the cross-linking reaction of the resin, forming a strong chemical bond between the inner and outer skins and the multi-layer absorbing panels, improving the bonding strength and structural stability.

[0071] In addition, in this embodiment, quartz fiber material is used as the outer skin to facilitate the electromagnetic waves to enter the interior of the absorbing plate and be absorbed; the inner skin is made of carbon fiber material, so that the electromagnetic waves entering the innermost side can be reflected again into the multi-layer absorbing plate to be absorbed and converted.

[0072] S6. After cutting, modifying and inspecting, the stealth plate is obtained.

[0073] Finally, the stealth plate processed in step S5 is cut out and modified, and the stealth plate is obtained after passing the inspection.

[0074] The stealth panel prepared by the present invention can be directly set on the outside of the cabin. It not only has wave-absorbing performance but also can serve as a structural layer to improve the overall structural performance. By changing the cabin panel structure, the exposed layer outside the cabin can meet the performance requirements to reduce the high cost of wave-absorbing coatings.

[0075] S7. Prepare the mold, lay the demoulding cloth, stealth plate, steel plate, and carbon fiber skeleton in the mold in sequence, place the polyurethane foam board in the skeleton frame of the carbon fiber skeleton, and then lay the carbon fiber cloth used to form the carbon fiber inner skin on the polyurethane foam board, lay the demoulding cloth on the polyurethane foam board, and then lay the guide net, encapsulate the vacuum bag film, and introduce the resin glue under vacuum negative pressure. After curing, demoulding, and polishing the appearance, an integrated board with wave-absorbing performance is obtained.

[0076] Laying release cloth on both the top and bottom can facilitate demoulding and prevent the plate from sticking to the vacuum bag film. Steel plates can be made of ultra-strong steel plates with a certain thickness.

[0077] Optionally, before the actual laying, pre-laying processing is also included, that is, after the mold is prepared, the stealth panel, carbon fiber skeleton and polyurethane foam panel are pre-laid in the mold. Specifically, the stealth panel is first pre-laid in the mold, and then the carbon fiber skeleton is pre-laid on the stealth panel, and then the polyurethane foam panel is adapted in the partition frame of the carbon fiber skeleton. The polyurethane foam panel is marked and numbered, and the stealth panel is also numbered and marked, and then placed in the assembly area.

[0078] Pre-laying allows for preliminary adjustments to the positions and angles of the panels, providing a reference for subsequent assembly. This helps identify any compatibility issues between the stealth panels, the frame, the polyurethane foam panels, and the mold, improving the efficiency and accuracy of the final layup.

[0079] Identifying and numbering the polyurethane foam boards and the like will help to quickly find the corresponding polyurethane foam boards and stealth boards during subsequent assembly.

[0080] After the pre-laying process is completed, the inside of the mold needs to be cleaned again to ensure that the mold surface is clean. Specifically, you can use dust-free cloth, compressed air, etc. to clean the mold surface to ensure that there are no impurities remaining on the mold surface.

[0081] After cleaning is completed, the release cloth, stealth plate, steel plate, carbon fiber frame, etc. can be laid in the mold in turn, and subsequent steps such as placing polyurethane foam board, release cloth and guide net can be carried out at the same time.

[0082] Among them, the guide net can provide a channel for the flow of resin glue, ensuring that the glue can be evenly distributed in various parts of the integrated board to achieve full infiltration.

[0083] Optionally, before officially introducing the resin adhesive, the vacuum bag is also tested for airtightness. This involves pre-evacuating the bag film after sealing it. Connect a vacuum pump and evacuate the sealed mold. The mold's airtightness is then checked by observing the vacuum gauge or using a vacuum leak detector. Ensuring mold tightness is crucial for a smooth resin introduction process. Leakage can prevent the resin adhesive from evenly soaking into the material, impacting the quality of the final integrated board.

[0084] While ensuring the mold is airtight, vacuum pressure is used to introduce resin glue into the mold, allowing it to fully penetrate every part of the mold and firmly bond the various layers together to form a single unit. During curing, the mold can be placed directly in a baking chamber at 80°C for four hours to ensure the internal glue is fully cured, resulting in the final integrated board with excellent wave-absorbing properties and exceptional strength.

[0085] Optionally, after polishing the appearance, it is usually possible to perform performance and function tests. For example, the prepared integrated board can be inspected through a series of test methods such as electromagnetic performance testing and mechanical performance testing to verify whether the prepared integrated board meets the design and use requirements. Only qualified ones can be used for subsequent cabin panels to ensure product quality.

[0086] The integrated board prepared by the present invention places a layer of ultra-strength steel plate of corresponding thickness between the stealth plate and the carbon fiber skeleton, which can ensure that the ultra-strength requirements are met while absorbing waves;

[0087] External electromagnetic wave signals are continuously reflected and weakened by the stealth panel. In order to prevent the projected signals from affecting the wave absorption performance, a layer of carbon fiber inner skin is laid on the innermost layer of the carbon fiber skeleton. The signal is reflected and refracted again through the carbon fiber layer. The reflected and refracted signals can be continuously weakened in the polyurethane foam board.

[0088] In addition, the use of carbon fiber skeleton can increase the strength and rigidity of the board itself. In the presence of ultra-high-strength steel plate, it can avoid damage to the polyurethane foam board due to strong external impact, which will cause loss of strength and rigidity. On the other hand, the carbon fiber profile is made of carbon fiber, and the impact of the signal on the carbon fiber profile surface can be reflected and refracted, and the polyurethane foam board also weakens the signal.

[0089] That is, the present invention improves the flatness and density of the inner surface of the cabin board by using a vacuum-assisted molding process in a mold to prepare the ultra-strength integrated board, thereby improving the structural strength of the ultra-strength integrated board and reducing the high cost of absorbing coatings.

[0090] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0091] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0092] In the description of this specification, the reference terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any at least one embodiment or example. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0093] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and simple improvements made to the essential contents of the present invention should be included in the scope of protection of the present invention.

Claims

1. A forming process for an integrated board with wave-absorbing performance, characterized in that: The integrated panel includes a carbon fiber skeleton, a skeleton bulkhead is formed in the carbon fiber skeleton, a polyurethane foam board is arranged in the skeleton bulkhead, a steel plate and a stealth plate are arranged on the outside of the carbon fiber skeleton, the steel plate is arranged between the carbon fiber skeleton and the stealth plate, and a carbon fiber inner skin is arranged on the inside of the carbon fiber skeleton; The molding process comprises the following steps: S1. Preparation of single-layer absorbing plate Apply adhesive on the resistor film, then lay the resistor film coated with adhesive on the PMI foam, and solidify it to obtain a single-layer absorbing board; S2. Performing a performance test on the single-layer absorbing panels, performing a numbering process, and then laser engraving the numbered single-layer absorbing panels; S3, repeating steps S1-S2 to prepare multiple single-layer absorbing panels, stacking the multiple single-layer absorbing panels one above the other, and bonding and curing them with an adhesive to obtain a multi-layer absorbing panel; S4, cutting and punching the obtained multi-layer absorbing plate; S5. Fixing the inner skin and the outer skin to the inner side and the outer side of the multi-layer absorbing plate respectively; S6, obtaining the stealth plate after cutting, modifying and inspecting; S7. Prepare a mold, lay the demoulding cloth, the stealth plate, the steel plate, and the carbon fiber skeleton in the mold in sequence, place a polyurethane foam board in the skeleton frame of the carbon fiber skeleton, and then lay the carbon fiber cloth used to form the carbon fiber inner skin on the polyurethane foam board, lay the demoulding cloth on the polyurethane foam board, and then lay the guide net, encapsulate the vacuum bag film, and introduce the resin glue under vacuum negative pressure. After curing, demoulding, and polishing the appearance, an integrated board with wave-absorbing performance is obtained.

2. The molding process according to claim 1, characterized in that: In step S1, the adhesive is obtained by mixing an epoxy resin and a curing agent, and the mixing ratio of the epoxy resin to the curing agent is 1:1-1.5; After the resistor film is laid on the PMI foam, it is placed on a press within 30 minutes for room temperature pressurization and curing; the curing time is 20-30 hours.

3. The molding process according to claim 1, characterized in that: In step S2, the performance test includes testing the sheet resistance of the single-layer absorbing plate at three points, namely, the left side, the middle, and the right side, using a sheet resistance tester to evaluate the resistance uniformity of the single-layer absorbing plate.

4. The molding process according to claim 1, characterized in that: In step S3, curing is specifically to place the stacked multiple single-layer absorbing panels on a press and perform press curing at room temperature for 20-30 hours.

5. The molding process according to claim 1, characterized in that: In step S4, the cutting is specifically performed by milling with an engraving machine, and the processed multi-layer absorbing plate has a length of 800-1200 mm, a width of 400-600 mm, and a thickness of 20-40 mm; the punching is specifically performed by using a punching template drill, and the hole diameter is 1.5-3 mm and the hole spacing is 20-40 mm.

6. The molding process according to claim 1, characterized in that: In step S5, the outer skin is formed by vacuum bagging quartz fiber; The inner skin is obtained by vacuum bagging carbon fibers; Lay the outer skin, the punched multi-layer absorbing plate and the inner skin in the mold frame. Before laying, apply epoxy resin between the layers to ensure that the resin is sufficient and uniform everywhere. Use quartz fiber cloth for edge and corner wrapping, and use vacuum bag pressing to form the inner skin, outer skin and the multi-layer absorbing plate into one piece.

7. The molding process according to claim 1, characterized in that: Step S7 also includes pre-laying the stealth panel, carbon fiber skeleton and polyurethane foam panel in the mold.

8. An integrated board with wave-absorbing properties obtained by the molding process according to any one of claims 1 to 7.

9. A shelter, characterized in that: Including the integrated board described in claim 8.

Images