Preparation method of infrared broadband radar flexible camouflage carbon felt car cover

Abstract

The present application belongs to the field of multi-spectrum camouflage technology, and particularly relates to a preparation method of a flexible camouflage carbon felt vehicle cover for infrared broadband radar, comprising the following steps: S1, raw material pretreatment: sequentially performing cleaning pretreatment, carbon ball stirring pretreatment and saturated sodium chloride solution spraying process treatment on the carbon fiber felt; S2, cutting: cutting the framework net and the carbon fiber felt after the step S1 treatment; S3, infrared camouflage treatment; S4, electromagnetic shielding treatment; S5, cutting and binding the carbon fiber felt after the electromagnetic shielding treatment into a net; and performing edge covering treatment on the carbon fiber felt after the binding into a net and the framework net after the step S2 cutting. After the cleaning, carbon ball stirring pretreatment and saturated sodium chloride solution spraying process treatment, the carbon fiber felt has extremely fine nanoscale grooves on the surface of a single fiber.

Description

Technical Field

[0001] This invention belongs to the field of multi-spectral camouflage technology, specifically relating to a method for preparing a flexible camouflage carbon felt car cover for infrared broadband radar. Background Technology

[0002] With the increasing complexity of the international strategic landscape and the application of high-precision weapons in modern warfare, the demand for anti-reconnaissance and camouflage capabilities of mobile, temporary, and secure meeting venues has surged globally. The improved capabilities of multi-spectral detection methods (synthetic aperture radar, visible / far-infrared imagers, and hyperspectral imaging detectors) such as satellites, high-altitude reconnaissance aircraft, and drones have brought reconnaissance accuracy down to the centimeter level. Imaging reconnaissance satellites, through panoramic high-resolution imaging of the battlefield and the monitoring, tracking, and identification of key targets, can quickly and accurately grasp the dynamics and real-time situation of ground targets, providing strong information support for precision strikes. Therefore, it is urgent to reduce the detectability of mobile secure meeting vehicles to achieve comprehensive camouflage in high-precision reconnaissance environments. For mobile meeting vehicle targets, effectively and efficiently evading satellite reconnaissance, reducing the probability of detection, and resisting close-range electromagnetic attacks are core factors in ensuring the self-protection capabilities and wartime survivability of key mobile targets.

[0003] Currently, the base materials of most widely used flexible camouflage products in my country are composite materials made of synthetic compounds such as polyester, polyamide, or polyester woven fabrics mixed with metal fibers. These materials possess efficient camouflage functions in a single frequency band, such as visible light camouflage, infrared camouflage, or radar camouflage. However, there are still some gaps in multi-spectral compatibility and performance consistency, making it difficult to simultaneously meet the actual requirements for camouflage functions in multiple frequency bands such as near-infrared, thermal infrared, and radar. They also lack electromagnetic shielding functions, making it difficult to protect against short-range electromagnetic interference. Due to the poor environmental adaptability of their base materials, their performance stability and service life will be severely reduced when used in harsh environments such as coastal areas, deserts, and plateaus, making it difficult to meet future usage requirements. Furthermore, existing camouflage materials are not suitable for the shape structure and surface paint color scheme of mobile secure conference vehicles.

[0004] Therefore, there is an urgent need for camouflage covers for mobile secure conference vehicles that do not affect the vehicle's operation while providing excellent multi-spectral camouflage capabilities. These covers should be lightweight, have good wind resistance, provide camouflage against infrared and multi-band radar detection, be easy to install and remove, and possess excellent environmental adaptability. Currently, there are no mature design schemes, manufacturing processes, or detailed processing techniques for this type of vehicle cover in China, leaving this field a market gap. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a flexible camouflage carbon felt car cover for infrared broadband radar. The prepared camouflage carbon felt car cover has functions of covering and preventing infrared reconnaissance camouflage, preventing multi-band radar reconnaissance camouflage, and protecting against electromagnetic attacks. It also has the characteristics of good wind resistance, low density, and strong environmental adaptability.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing an infrared broadband radar flexible camouflage carbon felt car cover includes the following steps:

[0008] S1. Raw material pretreatment: The carbon fiber felt is subjected to cleaning pretreatment, carbon ball stirring pretreatment, and saturated sodium chloride solution spraying process in sequence.

[0009] S2. Cutting: Cut the skeleton mesh and the carbon fiber felt processed in step S1.

[0010] S3. Infrared camouflage treatment: Apply infrared camouflage treatment to the upper surface of the carbon fiber felt after cutting in step S2.

[0011] S4. Electromagnetic shielding treatment: Electromagnetic shielding treatment is applied to the lower surface of the carbon fiber felt after infrared camouflage treatment in step S3.

[0012] S5. Cut the carbon fiber felt that has undergone electromagnetic shielding treatment into patterns and bind it into a net; then bind the carbon fiber felt that has been bound into a net with the skeleton net that was cut in step S2.

[0013] In step S1, the cleaning pretreatment refers to: first, treating the carbon fiber felt with heat and drying for 1 to 2 hours; then, removing impurities from the surface of the carbon fiber felt by solvent cleaning; and finally, drying treatment.

[0014] In step S1, the carbon ball stirring pretreatment refers to adding distilled water, carbon fiber felt and high-purity carbon balls into a magnetic stirring container and stirring at a slow speed of 300-600 rpm for 5-10 hours. Through the collision and friction between the carbon balls and the carbon fiber felt, micropore defects are formed on the surface of the carbon fiber felt.

[0015] In step S1, the saturated sodium chloride solution spraying process refers to: uniformly spraying saturated sodium chloride solution onto the upper and lower surfaces of the carbon fiber felt, keeping it horizontally dry at room temperature, placing it in a cool, dark place for a period of time, and then rinsing it with deionized water.

[0016] The surface layer of the carbon fiber felt is prepared at a concentration of 2-3 g / m 2 After uniformly spraying a saturated sodium chloride solution at a controlled spray density and allowing it to dry horizontally at room temperature for 5–10 minutes, apply a coating of 2–3 g / m² to the lower surface of the carbon fiber. 2Apply a saturated sodium chloride solution evenly with the appropriate spray density. After drying horizontally at room temperature for 5-10 minutes, place it in a cool, dark place (ambient humidity > 20%) for 144-240 hours. Rinse 3-5 times with deionized water and store in a dry, cool place until ready for use.

[0017] In step S3: the infrared camouflage coating is dispersed for 10-20 minutes, and then the infrared camouflage coating is sprayed onto the surface of the carbon fiber felt; after the spraying is completed, the carbon fiber felt is placed horizontally in a clean and ventilated place, and after the coating surface dries, it is folded and stored in a dry and ventilated place to complete the infrared camouflage treatment process on the surface of the carbon fiber felt.

[0018] In step S4: the carbon nanotube conductive coating is dispersed for 5 to 10 minutes, and then the conductive coating is sprayed onto the lower surface of the carbon fiber felt; after the spraying is completed, the carbon fiber felt is placed horizontally in a clean and ventilated place. After the coating surface dries, it can be folded and stored in a dry and ventilated place to complete the electromagnetic shielding treatment process of the lower surface of the carbon fiber felt.

[0019] Step S4 is performed sequentially 24 hours after step S3 is completed.

[0020] In step S5, the cutting of flowers refers to: placing the spliced ​​carbon fiber felt on a flower cutting machine; laying the carbon fiber felt flat, with 20 to 30 layers on each sheet, ensuring the edges are neat and the vertical error is no more than 5mm; and after stacking the carbon fiber felt, placing it neatly and parallel on the flower cutting machine corresponding to the flower pattern for cutting.

[0021] The process of binding the net involves: laying the carbon fiber felt flat on the workbench, then laying the skeleton net flat on the carbon fiber felt and adjusting it to be even and flat; using binding thread for binding, the binding structure is diamond-shaped, the binding density is controlled at 25 to 35 knots per square meter, the knot type is self-tightening, each knot is tied 3 to 5 times, the direction of the thread is forward and backward, and it is tied tightly, leaving a knot length of 20mm to 30mm.

[0022] In step S5, the edge binding refers to: aligning the carbon fiber felt and the skeleton mesh on both sides, and completely wrapping them inside the edge binding strip along with the edge ropes. The stitches should be even, without any skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton mesh should be re-stitched 3-5 times, with the repeated stitches completely covering the length. The connecting loop ropes should not be missing, and the stitches should be flat and secure.

[0023] The length and spacing of the connecting rings must be within the tolerance range. The length of the connecting ring rope is 200mm ± 20mm, and the spacing of the connecting ring ropes is 200mm ± 20mm.

[0024] Make cuts of about 15-25mm depth at intervals of 150-250mm on the strip of fabric to facilitate the production of the rope;

[0025] When binding the edges, the edge rope joints should be sewn at the center of any side length, and sewing at the four corners is not allowed.

[0026] Compared with the prior art, the beneficial effects of this invention are:

[0027] 1. A novel method for preparing flexible camouflage carbon felt car covers for infrared / broadband radar is proposed for the first time, which solves the problem of anti-reconnaissance of mobile conference vehicles. The prepared flexible camouflage carbon felt car covers for infrared / broadband radar can have comprehensive camouflage functions.

[0028] 2. The key innovation of the selection of raw material components and preparation method of the new infrared / broadband radar flexible camouflage carbon felt car cover is the use of carbon fiber felt, skeleton mesh and functional coating as raw materials, and the surface pretreatment, layout and cutting, upper and lower surface spraying, cutting, binding into net and edge binding processes to prepare an infrared / broadband radar flexible camouflage carbon felt car cover that can be used for camouflage of mobile confidential conference vehicles.

[0029] 3. Preparation process and parameters of novel infrared / broadband radar flexible camouflage carbon felt car cover. Key innovations include the overall structural design, carbon fiber felt surface modification, functional coating spraying, and other process flow and parameters.

[0030] Currently, there are no mature flexible camouflage carbon felt car covers for infrared / broadband radar that can be used for multi-band comprehensive protection of mobile secure conference vehicles. Through the design and application of novel protective materials, a series of comprehensive protective camouflage products for mobile conference vehicles can be developed, covering camouflage against infrared reconnaissance, camouflage against multi-band radar reconnaissance, and electromagnetic interference protection. Based on the present invention, the flexible camouflage carbon felt car cover for infrared / broadband radar has a surface density reduced to 200 g / m² compared to existing camouflage materials. 2 With a thickness of less than 1cm, it significantly improves environmental adaptability while meeting camouflage performance requirements, has a service life of no less than 2 years, and ensures stable and reliable camouflage protection for a long time, thus providing a guarantee for improving the safety factor of the mobile conference vehicle.

[0031] It mainly addresses the following shortcomings of existing technologies:

[0032] 1. Currently, there is no high-performance, lightweight, quick-release flexible camouflage material for infrared / broadband radar. The scarcity of lightweight, high-performance materials limits the research and development and production of camouflage covers for mobile secure conference vehicles.

[0033] 2. Traditional camouflage materials do not have electromagnetic shielding capabilities. Camouflage materials that also have protection against near-infrared, thermal infrared, and radar waves are heavy (usually composed of multiple layers, weighing 500-1000 grams per square meter) and occupy a large amount of vehicle interior space (the volume of a traditional 25-square-meter camouflage net is about 0.5 cubic meters), which causes inconvenience to the operation of mobile confidential conference vehicles and the installation and removal of camouflage covers.

[0034] 3. Traditional camouflage materials typically require the use of metallic components to achieve broadband radar camouflage and electromagnetic shielding. However, these materials oxidize during long-term outdoor use, resulting in a significant decrease in performance.

[0035] 4. Traditional carbon fiber felt surface treatment processes mostly use strong oxidizing agents such as strong acids and alkalis, which not only pose safety hazards during production but also seriously pollute the environment with wastewater and waste materials. This invention achieves functional modification of the entire carbon fiber felt and key surface areas solely through the use of non-toxic and harmless raw materials such as high-purity carbon balls and sodium chloride. After cleaning, carbon ball stirring pretreatment, and saturated sodium chloride solution spraying, the surface of each individual fiber of the carbon fiber felt exhibits extremely fine nanoscale grooves. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the rolled infrared / broadband radar flexible camouflage carbon felt car cover product of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the infrared / broadband radar flexible camouflage carbon felt car cover of the present invention;

[0038] Figure 3 This is a top view of the carbon fiber felt / skeleton mesh structure of the present invention;

[0039] Figure 4 This is a structural morphology diagram of the carbon fiber felt of the present invention;

[0040] Figure 5 This is a microscopic morphology diagram of the carbon fiber felt of the present invention;

[0041] Figure 6 This is a detailed surface view of a single fiber of the original carbon fiber felt of this invention;

[0042] Figure 7 This is a detailed image of the surface of a single fiber of carbon fiber felt after the present invention has undergone cleaning, carbon ball stirring pretreatment, and saturated sodium chloride solution spraying process.

[0043] Figure 8 This is a schematic diagram of the microstructure of the carbon nanotube conductive coating of the present invention;

[0044] Figure 9 This is a sample reflectance test curve from Embodiment 1 of the present invention;

[0045] Figure 10 This is the sample reflectance test curve in Embodiment 2 of the present invention;

[0046] Figure 11 This is the sample reflectance test curve in Embodiment 3 of the present invention. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0048] like Figure 1-8 As shown, a method for preparing an infrared broadband radar flexible camouflage carbon felt car cover includes the following steps:

[0049] Selection of main raw materials:

[0050] ① Fiber felt:

[0051] Carbon fiber filament diameter: 15–30 μm

[0052] Impurity content: <10ppm

[0053] Density: Three levels are set according to radar wave / infrared camouflage requirements: Level A 0.07g / cm³ 3 Grade B 0.08g / cm 3 Grade C and Grade A: 0.09g / cm³ 3 Performance levels increase progressively from A to C.

[0054] ② Infrared camouflage treatment on the upper surface of carbon fiber felt: Infrared camouflage coating

[0055] Composition: Polyurethane resin, fluorocarbon resin, and dimethyl silicone resin coatings containing low emissivity fillers such as MgO, FeO, and ZnO.

[0056] ③ Electromagnetic shielding treatment at the bottom of carbon fiber felt: carbon nanotube conductive coating

[0057] Composition: Polyurethane and epoxy resin coatings containing pure carbon-based conductive fillers such as graphene, mexene, and highly conductive graphite.

[0058] Sheet resistance after paint drying: <0.1Ω / sq

[0059] ④ Skeleton mesh:

[0060] Main component: Nylon yarn

[0061] Wire type: Warp (840D / 3), Weft (840D / 3)

[0062] Aperture: (50±10)mm × (50±10)mm

[0063] ⑤ Carbon balls:

[0064] Carbon content: >99.9%

[0065] Carbon sphere diameter: 3–5 μm

[0066] Main preparation process

[0067] S1. Raw material pretreatment:

[0068] (1) Cleaning and pretreatment of raw materials (carbon fiber felt). This mainly involves removing residual activators and adsorbed water from the powder surface during the preparation process to reduce the adverse effects of impurities on material properties in the later stages of the reaction. In this invention, impurities on the surface of raw materials are removed by heating (120℃~160℃) for 1~2 hours and cleaning with solvents (ethanol, acetone), followed by drying.

[0069] (2) Functionalize the surface of carbon fiber felt to improve the adhesion of subsequent functional coatings. Add distilled water, carbon fiber felt, and high-purity carbon balls in a mass ratio of 10L:100g:200g to a magnetically stirred container. Stir slowly at 300-600 rpm for 5-10 hours, ensuring the carbon fiber felt and carbon balls rotate in the distilled water. Through collision and friction between the carbon balls and carbon fiber felt, microporous defects are formed on the surface of the carbon fiber felt. After the reaction, remove the carbon fiber felt and rinse it 3-5 times with deionized water. Finally, dry it in a 50℃ oven for 12-16 hours and store it in a dry, cool place until use. Filter the remaining carbon balls from the remaining solution; if the quality meets the parameter requirements, reuse the solution.

[0070] (3) After the previous step is completed, the carbon fiber felt is in the same surface functionalization pretreatment state. The focus of this process is to treat the upper and lower surfaces of the carbon fiber felt. A precision spray control system is used to apply 2-3 g / m² spray to the upper surface of the carbon fiber felt. 2 After uniformly spraying a saturated sodium chloride solution at a controlled spray density and allowing it to dry horizontally at room temperature for 5–10 minutes, apply a coating of 2–3 g / m² to the lower surface of the carbon fiber. 2 The spray density is adjusted, and a saturated sodium chloride solution is sprayed evenly. After drying horizontally at room temperature for 5-10 minutes, it is placed in a cool, dark place (ambient humidity > 20%) for 144-240 hours. Then, it is rinsed 3-5 times with deionized water and stored in a dry, cool place until use. This process achieves further functional modification of the upper and lower surfaces of the carbon fiber felt. Unlike traditional strong oxidants such as nitric acid, which struggle to control the surface modification effect and cause a decline in carbon fiber felt performance, this process creates a continuous groove microstructure on the surface. During subsequent coating application to the upper and lower surfaces of the carbon fiber felt, the coating components can penetrate into the grooves and gaps, resulting in a significant mechanical interlocking effect with the carbon fiber surface after curing. This significantly improves the interfacial strength and effectively enhances the adhesion of the cured coating.

[0071] Figure 7 The image clearly shows the surface details of individual carbon fiber felt fibers after cleaning, carbon ball stirring pretreatment, and saturated sodium chloride solution spraying: extremely fine nanoscale grooves appear on the fiber surface; and Figure 6The image shows the surface details of a single fiber of the original carbon fiber felt: the fiber surface is flat and smooth.

[0072] S2. Cutting: Cut the skeleton mesh and the carbon fiber felt processed in step S1.

[0073] (1) Cut carbon fiber felt. According to the layout size, the thickness of carbon fiber felt should be controlled at 5-8mm. The edge of the fabric should be neat and free of burrs.

[0074] (2) The mesh size of the skeleton mesh must be accurate. The number of meshes must be calculated accurately when cutting. The size of each skeleton mesh hole is (50±10)mm×(50±10)mm.

[0075] S3. Infrared camouflage treatment: Apply infrared camouflage treatment to the upper surface of the carbon fiber felt after cutting in step S2.

[0076] (1) Disperse the infrared camouflage coating at a speed of 100 rpm for 10 to 20 minutes, and apply the infrared camouflage coating to the upper surface of the carbon fiber felt using the following spraying process.

[0077]

[0078] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 4 hours. After the coating surface is dry, fold it and store it in a dry and ventilated place for 96 hours to complete the infrared camouflage treatment process on the upper surface of the carbon fiber felt.

[0079] S4. Electromagnetic shielding treatment: Electromagnetic shielding treatment is applied to the lower surface of the carbon fiber felt after infrared camouflage treatment in step S2.

[0080] (1) Disperse the carbon nanotube conductive coating at a speed of 100 rpm for 5 to 10 minutes, and spray the conductive coating onto the lower surface of the carbon fiber felt using the following spraying process.

[0081]

[0082] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 2 hours. After the coating surface is dry, it can be folded and stored in a dry and ventilated place for 48 hours to complete the electromagnetic shielding treatment process on the lower surface of the carbon fiber felt.

[0083] Note: Step 4 should be performed 24 hours after step 3 is completed. The order of steps 3 and 4 cannot be reversed.

[0084] S5. Cut the carbon fiber felt that has undergone electromagnetic shielding treatment into patterns and bind it into a net; then bind the carbon fiber felt that has been bound into a net with the skeleton net that was cut in step S2.

[0085] Cutting flowers: (1) First, cut the flower notch size according to the design drawing requirements, with a notch size of R(15~20)mm, and place the spliced ​​carbon fiber felt on the flower cutting machine. (2) Lay the carbon fiber felt flat, with 20~30 layers per sheet. The edges of the fabric should be neat, and the vertical error should not exceed 5mm. If any unqualified or substandard carbon fiber felt is found, it should not be cut or punched. After stacking the carbon fiber felt, place it neatly and parallel on the flower cutting machine corresponding to the flower pattern, ready for cutting. (3) Flower cutting machine settings: cutting stroke: 180mm, pressure 0.15-0.3MPa.

[0086] Binding into a net: (1) Laying flat: First, lay the carbon fiber felt flat on the workbench, then lay the skeleton net flat on the carbon fiber felt, and adjust it to be even and flat. (2) Binding: Use binding thread to bind, the binding structure is diamond-shaped, the binding density is controlled at 25 to 35 knots per square meter, the knot type is self-tightening, one knot is tied 3 to 5 times, the direction of the winding thread is forward and backward, tie it tightly, and leave the knot head 20mm to 30mm long.

[0087] Binding: (1) Carbon fiber felt and skeleton mesh, the two layers are aligned top and bottom, and the edge ropes are completely wrapped inside the binding strip. The stitches are even and there are no skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton mesh is re-stitched 3-5 times. The length of the repeated stitches is completely covered. The connecting loop rope is not missing. The stitches are flat and firm. (2) The length and spacing of the connecting loops are within the tolerance range. The length of the connecting loop rope is 200mm±20mm and the spacing of the connecting loop ropes is 200mm±20mm.

[0088] (3) Make cuts of about 15 to 25 mm depth at intervals of 150 to 250 mm on the strip of cloth to facilitate the release of the rope.

[0089] (4) When binding the edges, the edge rope joints should be sewn at the center of any side length on the four sides, and sewing at the four corners is not allowed.

[0090] It also includes finished product inspection and packaging: unfold the sewn camouflage carbon felt car cover horizontally, remove debris, trim the threads, roll it up, and pack it into a packaging bag to complete the entire camouflage car cover preparation process.

[0091] To further illustrate, the following examples are provided:

[0092] Example 1:

[0093] 1. Raw material pretreatment

[0094] (1) The raw materials (Grade B carbon fiber felt) are pretreated by cleaning. This mainly removes the surfactants and adsorbed water remaining on the surface of the powder during the preparation process, so as to reduce the adverse effects of impurities on the material properties in the later stage of the reaction. In this invention, the raw materials are dried at 120°C for 2 hours, then ultrasonically cleaned with acetone and ethanol, and finally filtered and dried at room temperature.

[0095] (2) Functionalize the surface of carbon fiber felt to improve the adhesion of subsequent functional coatings. Add distilled water, carbon fiber felt, and high-purity carbon balls in a mass fraction ratio of 10L:100g:200g to a magnetically stirred container and stir slowly at 600 rpm for 5 hours to ensure that the carbon fiber felt and carbon balls rotate in the distilled water. After the reaction is complete, remove the carbon fiber felt and rinse it 5 times with deionized water. Finally, dry it in a 50℃ oven for 16 hours and store it in a dry and cool place for later use. Filter the remaining carbon balls from the remaining solution and reuse them after the quality is judged to meet the parameter requirements.

[0096] (3) After the previous step is completed, the carbon fiber felt is in the same surface functionalization pretreatment state. The focus of this process is to treat the upper and lower surfaces of the carbon fiber felt. A precision spray control system is used to apply a 2.5g / m² spray to the upper surface of the carbon fiber felt. 2 The spraying density was adjusted, and a saturated sodium chloride solution was sprayed evenly. After drying horizontally at room temperature for 8 minutes, a coating layer of 2.5 g / m was applied to the lower surface of the carbon fiber. 2 The carbon fiber felt is sprayed with a saturated sodium chloride solution at a uniform spray density. After drying horizontally at room temperature for 8 minutes, it is placed in a cool, dark place (ambient humidity > 20%) for 196 hours. Then, it is rinsed four times with deionized water and stored in a dry, cool place until use. This process achieves key functional modifications to the upper and lower surfaces of the carbon fiber felt.

[0097] 2. Cutting composite carbon felt and skeleton mesh

[0098] (1) Cut the composite carbon felt. According to the layout size, the thickness of the carbon fiber felt should be controlled at 8mm. The edge of the fabric should be neat and burr-free.

[0099] (2) The mesh size of the skeleton mesh must be accurate. When cutting, the number of meshes must be calculated accurately. The size of each skeleton mesh hole is 50mm×50mm.

[0100] 3. Infrared camouflage treatment on the upper surface of carbon fiber felt

[0101] (1) Disperse the infrared coating at a speed of 100 rpm for 10 minutes, and apply the infrared camouflage coating to the upper surface of the carbon fiber felt using the following spraying process.

[0102]

[0103] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 4 hours. After the coating surface is dry, fold it and store it in a dry and ventilated place for 96 hours to complete the infrared camouflage treatment process on the upper surface of the carbon fiber felt.

[0104] 4. Electromagnetic shielding treatment on the lower surface of carbon fiber felt

[0105] (1) Disperse the carbon nanotube conductive coating at a speed of 100 rpm for 5 minutes, and apply the electromagnetic shielding coating to the lower surface of the carbon fiber felt using the following spraying process.

[0106]

[0107] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 2 hours. After the coating surface is dry, it can be folded and stored in a dry and ventilated place for 48 hours to complete the electromagnetic shielding treatment process on the lower surface of the carbon fiber felt.

[0108] Note: Step 4 should be performed 24 hours after step 3 is completed. The order of steps 3 and 4 cannot be reversed.

[0109] 5 cut flowers

[0110] (1) First, cut the flower notch size according to the design drawing requirements of R15mm, and place the spliced ​​carbon fiber felt on the flower cutting machine.

[0111] (2) Lay the carbon fiber felt flat, with 25 layers per sheet. The edges of the fabric should be neat and the vertical error should not exceed 5mm. Any unqualified or substandard carbon fiber felt should not be cut or punched. After stacking the carbon fiber felt, place it neatly and parallel on the flower cutting machine of the corresponding pattern as required, ready for cutting.

[0112] (3) Flower cutting machine setting data

[0113] Flower cutting stroke: 200mm, pressure: 0.20MPa.

[0114] 6. Tie into a net

[0115] (1) Lay flat

[0116] First, lay the carbon fiber felt flat on the workbench, then lay the skeleton mesh flat on the carbon fiber felt, and adjust it to be even and flat.

[0117] (2) Binding

[0118] Use binding thread for binding. The binding structure is diamond-shaped. The binding density is controlled at 25 knots per square meter. The knot type is self-tightening. Each knot is tied 5 times. The direction of the thread wrapping is forward and backward. Tighten the knot completely and leave a 25mm length at the end.

[0119] 7. Edge binding

[0120] (1) Carbon fiber felt and skeleton net, the two layers are aligned top and bottom, and the edge ropes are completely wrapped inside the binding strip. The stitches are even and there are no skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton net is sewn three times. The length of the repeated stitches is completely covered. The connecting loop rope is not missing. The stitches are flat and firm.

[0121] (2) The length and spacing of the connecting rings must be within the tolerance range. The length of the connecting ring rope is 200mm and the spacing of the connecting ring ropes is 200mm.

[0122] (3) Make cuts of about 25mm depth at intervals of 150mm on the strip of cloth to facilitate the release of the rope.

[0123] (4) When binding the edges, the edge rope joints should be sewn at the center of any side length on the four sides, and sewing at the four corners is not allowed.

[0124] 8. Finished Product Inspection and Packaging

[0125] Unfold the sewn camouflage carbon felt car cover horizontally, remove debris and trim loose threads, roll it up, and pack it into a bag to complete the entire camouflage car cover preparation process.

[0126] The sample prepared in Example 1 can significantly reduce the difference in infrared energy between the target and the background, improve the consistency of the infrared characteristics of the vehicle and the background, and the average thermal radiation temperature difference with the typical background is no more than 4°C.

[0127] like Figure 9 As shown, the product has excellent radar stealth performance.

[0128] Example 2:

[0129] 1. Raw material pretreatment

[0130] (1) The raw materials (Grade A carbon fiber felt) are pretreated by cleaning. This mainly removes the surfactants and adsorbed water remaining on the surface of the powder during the preparation process, so as to reduce the adverse effects of impurities on the material properties in the later stage of the reaction. In this invention, the raw materials are dried at 140°C for 1.5 hours, then ultrasonically cleaned with acetone and ethanol, and finally filtered and dried at room temperature.

[0131] (2) Functionalize the surface of carbon fiber felt to improve the adhesion of subsequent functional coatings. Add distilled water, carbon fiber felt, and high-purity carbon balls in a mass fraction ratio of 10L:100g:200g to a magnetically stirred container and stir slowly at 300 rpm for 10 hours to ensure that the carbon fiber felt and carbon balls rotate in the distilled water. After the reaction is complete, remove the carbon fiber felt and rinse it three times with deionized water. Finally, dry it in a 50℃ oven for 12 hours and store it in a dry and cool place for later use. Filter the remaining carbon balls from the remaining solution and reuse them after the quality is judged to meet the parameter requirements.

[0132] (3) After the previous step is completed, the carbon fiber felt is in the same surface functionalization pretreatment state. The focus of this process is to treat the upper and lower surfaces of the carbon fiber felt. A precision spray control system is used to apply 2g / m² spray to the upper surface of the carbon fiber felt. 2After uniformly spraying a saturated sodium chloride solution at a certain spray density and allowing it to dry horizontally at room temperature for 5 minutes, apply a layer of 2 g / m² onto the lower surface of the carbon fiber. 2 The carbon fiber felt is sprayed with a saturated sodium chloride solution at a uniform spray density. After drying horizontally at room temperature for 5 minutes, it is placed in a cool, dark place (ambient humidity > 20%) for 144 hours. Then, it is rinsed three times with deionized water and stored in a dry, cool place until use. This process achieves key functional modifications to the upper and lower surfaces of the carbon fiber felt.

[0133] 2. Cutting composite carbon felt and skeleton mesh

[0134] (1) Cut the composite carbon felt. According to the layout size, the thickness of the carbon fiber felt should be controlled at 6mm. The edge of the fabric should be neat and burr-free.

[0135] (2) The mesh size of the skeleton mesh must be accurate. The number of meshes must be calculated accurately when cutting. The size of each skeleton mesh hole is 60mm×60mm.

[0136] 3. Infrared camouflage treatment on the upper surface of carbon fiber felt

[0137] (1) Disperse the infrared coating at a speed of 100 rpm for 15 minutes, and apply the infrared camouflage coating to the upper surface of the carbon fiber felt using the following spraying process.

[0138]

[0139] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 4 hours. After the coating surface is dry, fold it and store it in a dry and ventilated place for 96 hours to complete the infrared camouflage treatment process on the upper surface of the carbon fiber felt.

[0140] 4. Electromagnetic shielding treatment on the lower surface of carbon fiber felt

[0141] (1) Disperse the carbon nanotube conductive coating at a speed of 100 rpm for 8 minutes, and apply the electromagnetic shielding coating to the lower surface of the carbon fiber felt using the following spraying process.

[0142]

[0143] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 2 hours. After the coating surface is dry, it can be folded and stored in a dry and ventilated place for 48 hours to complete the electromagnetic shielding treatment process on the lower surface of the carbon fiber felt.

[0144] Note: Step 4 should be performed 24 hours after step 3 is completed. The order of steps 3 and 4 cannot be reversed.

[0145] 5 cut flowers

[0146] (1) First, cut the flower notch size according to the design drawing requirements of R18mm, and place the spliced ​​carbon fiber felt on the flower cutting machine.

[0147] (2) Lay the carbon fiber felt flat, with 30 layers per sheet. The edges of the fabric should be neat and the vertical error should not exceed 5mm. If any unqualified or substandard carbon fiber felt is found, it should not be cut or punched. After stacking the carbon fiber felt, place it neatly and parallel on the flower cutting machine of the corresponding pattern as required, ready for cutting.

[0148] (3) Flower cutting machine setting data

[0149] Flower cutting stroke: 180mm, pressure: 0.15MPa.

[0150] 6. Tie into a net

[0151] (1) Lay flat

[0152] First, lay the carbon fiber felt flat on the workbench, then lay the skeleton mesh flat on the carbon fiber felt, and adjust it to be even and flat.

[0153] (2) Binding

[0154] Use binding thread for binding. The binding structure is diamond-shaped. The binding density is controlled at 30 knots per square meter. The knot type is self-tightening. Each knot is tied 4 times. The direction of the thread wrapping is forward and backward. Tighten the knot completely and leave a 20mm length at the end.

[0155] 7. Edge binding

[0156] (1) Carbon fiber felt and skeleton net, the two layers are aligned top and bottom, and the edge ropes are completely wrapped inside the binding strip. The stitches are even and there are no skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton net is sewn with 5 stitches. The length of the repeated stitches is completely covered. The connecting loop rope is not missing. The stitches are flat and firm.

[0157] (2) The length and spacing of the connecting rings must be within the tolerance range. The length of the connecting ring rope is 220mm and the spacing of the connecting ring ropes is 220mm.

[0158] (3) Make cuts of about 15mm depth at intervals of 250mm on the strip of cloth to facilitate the release of the rope.

[0159] (4) When binding the edges, the edge rope joints should be sewn at the center of any side length on the four sides, and sewing at the four corners is not allowed.

[0160] 8. Finished Product Inspection and Packaging

[0161] Unfold the sewn camouflage carbon felt car cover horizontally, remove debris and trim loose threads, roll it up, and pack it into a bag to complete the entire camouflage car cover preparation process.

[0162] The sample prepared in Example 2 can significantly reduce the difference in infrared energy between the target and the background, improve the consistency of the infrared characteristics of the vehicle and the background, and the average thermal radiation temperature difference with the typical background is no more than 4°C.

[0163] like Figure 10 As shown, the product has excellent radar stealth performance.

[0164] Example 3:

[0165] 1. Raw material pretreatment

[0166] (1) The raw materials (Grade C carbon fiber felt) are pretreated by cleaning. This mainly removes the surfactants and adsorbed water remaining on the surface of the powder during the preparation process, so as to reduce the adverse effects of impurities on the material properties in the later stage of the reaction. In this invention, the raw materials are dried at 160°C for 1.0 hour, then ultrasonically cleaned with acetone and ethanol, and filtered and dried at room temperature.

[0167] (2) Functionalize the surface of carbon fiber felt to improve the adhesion of subsequent functional coatings. Add distilled water, carbon fiber felt, and high-purity carbon balls in a mass fraction ratio of 10L:100g:200g to a magnetically stirred container and stir slowly at 400 rpm for 8 hours to ensure that the carbon fiber felt and carbon balls rotate in the distilled water. After the reaction is complete, remove the carbon fiber felt and rinse it 4 times with deionized water. Finally, dry it in a 50℃ oven for 14 hours and store it in a dry and cool place for later use. Filter the remaining carbon balls from the remaining solution and reuse them after the quality is judged to meet the parameter requirements.

[0168] (3) After the previous step is completed, the carbon fiber felt is in the same surface functionalization pretreatment state. The focus of this process is to treat the upper and lower surfaces of the carbon fiber felt. A precision spray control system is used to apply 3g / m² spray to the upper surface of the carbon fiber felt. 2 After uniformly spraying a saturated sodium chloride solution at a certain spray density and allowing it to dry horizontally at room temperature for 10 minutes, apply a coating to the lower surface of the carbon fiber at a density of 3 g / m². 2 The coating density is adjusted, and a saturated sodium chloride solution is sprayed evenly. After drying horizontally at room temperature for 10 minutes, it is placed in a cool, dark place (ambient humidity > 20%) for 240 hours. Then, it is rinsed five times with deionized water and stored in a dry, cool place until use. This process achieves key functional modifications to the upper and lower surfaces of the carbon fiber felt.

[0169] 2. Cutting composite carbon felt and skeleton mesh

[0170] (1) Cut the composite carbon felt. According to the layout size, the thickness of the carbon fiber felt should be controlled at 5mm. The edge of the fabric should be neat and burr-free.

[0171] (2) The mesh size of the skeleton mesh must be accurate. The number of meshes must be calculated accurately when cutting. The size of each skeleton mesh hole is 40mm×40mm.

[0172] 3. Infrared camouflage treatment on the upper surface of carbon fiber felt

[0173] (1) Disperse the infrared coating at a speed of 100 rpm for 20 minutes, and apply the infrared camouflage coating to the upper surface of the carbon fiber felt using the following spraying process.

[0174]

[0175] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 4 hours. After the coating surface is dry, fold it and store it in a dry and ventilated place for 96 hours to complete the infrared camouflage treatment process on the upper surface of the carbon fiber felt.

[0176] 4. Electromagnetic shielding treatment on the lower surface of carbon fiber felt

[0177] (1) Disperse the carbon nanotube conductive coating at a speed of 100 rpm for 10 minutes, and apply the electromagnetic shielding coating to the lower surface of the carbon fiber felt using the following spraying process.

[0178]

[0179] (2) After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place for 2 hours. After the coating surface is dry, it can be folded and stored in a dry and ventilated place for 48 hours to complete the electromagnetic shielding treatment process on the lower surface of the carbon fiber felt.

[0180] Note: Step 4 should be performed 24 hours after step 3 is completed. The order of steps 3 and 4 cannot be reversed.

[0181] 5 cut flowers

[0182] (1) First, cut the flower notch size according to the design drawing requirements of R20mm, and place the spliced ​​carbon fiber felt on the flower cutting machine.

[0183] (2) Lay the carbon fiber felt flat, with 20 layers per sheet. The edges of the fabric should be neat and the vertical error should not exceed 5mm. If any unqualified or substandard carbon fiber felt is found, it should not be cut or punched. After stacking the carbon fiber felt, place it neatly and parallel on the flower cutting machine of the corresponding pattern as required, ready for cutting.

[0184] (3) Flower cutting machine setting data

[0185] Flower cutting stroke: 180mm, pressure: 0.30MPa.

[0186] 6. Tie into a net

[0187] (1) Lay flat

[0188] First, lay the carbon fiber felt flat on the workbench, then lay the skeleton mesh flat on the carbon fiber felt, and adjust it to be even and flat.

[0189] (2) Binding

[0190] Use binding thread for binding. The binding structure is diamond-shaped. The binding density is controlled at 35 knots per square meter. The knot type is self-tightening. Each knot is tied 3 times. The direction of the thread wrapping is forward and backward. Tighten the knot completely and leave a 30mm length at the end.

[0191] 7. Edge binding

[0192] (1) Carbon fiber felt and skeleton net, the two layers are aligned top and bottom, and the edge ropes are completely wrapped inside the binding strip. The stitches are even and there are no skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton net is sewn with 4 stitches. The length of the repeated stitches is completely covered. The connecting loop rope is not missing. The stitches are flat and firm.

[0193] (2) The length and spacing of the connecting rings must be within the tolerance range. The length of the connecting ring rope is 180mm and the spacing of the connecting ring ropes is 180mm.

[0194] (3) Make cuts of about 20mm depth at intervals of 200mm on the strip of cloth to facilitate the release of the rope.

[0195] (4) When binding the edges, the edge rope joints should be sewn at the center of any side length on the four sides, and sewing at the four corners is not allowed.

[0196] 8. Finished Product Inspection and Packaging

[0197] Unfold the sewn camouflage carbon felt car cover horizontally, remove debris and trim loose threads, roll it up, and pack it into a bag to complete the entire camouflage car cover preparation process.

[0198] The sample prepared in Example 3 can significantly reduce the difference in infrared energy between the target and the background, improve the consistency of the infrared characteristics of the vehicle and the background, and the average thermal radiation temperature difference with the typical background is no more than 4°C.

[0199] like Figure 11 As shown, the product has excellent radar stealth performance.

[0200] The above description only illustrates preferred embodiments of the present invention, but the present invention is not limited to the above embodiments.

Claims

1. A method for preparing an infrared broadband radar flexible camouflage carbon felt car cover, characterized in that, Includes the following steps: S1. Raw material pretreatment: The carbon fiber felt is subjected to cleaning pretreatment, carbon ball stirring pretreatment, and saturated sodium chloride solution spraying process in sequence. In step S1, the carbon ball stirring pretreatment refers to: adding distilled water, carbon fiber felt and high-purity carbon balls into a magnetic stirring container, and stirring at a slow speed of 300~600 rpm for 5~10 hours. Through the collision and friction between the carbon balls and the carbon fiber felt, micropore defects are formed on the surface of the carbon fiber felt. In step S1, the saturated sodium chloride solution spraying process refers to: uniformly spraying saturated sodium chloride solution onto the upper and lower surfaces of the carbon fiber felt, keeping it horizontally dry at room temperature, placing it in a cool, dark place for a period of time, and then rinsing it with deionized water. This process forms a continuous groove microstructure on the surface of the carbon fiber felt. During the subsequent coating process on the upper and lower surfaces of the carbon fiber felt, the coating components penetrate into the groove gaps, which can improve the interface strength and improve the coating adhesion. S2. Cutting: Cut the skeleton mesh and the carbon fiber felt processed in step S1. S3. Infrared camouflage treatment: Apply infrared camouflage treatment to the upper surface of the carbon fiber felt after cutting in step S2. S4. Electromagnetic shielding treatment: Electromagnetic shielding treatment is applied to the lower surface of the carbon fiber felt after infrared camouflage treatment in step S3. S5. Cut the carbon fiber felt that has undergone electromagnetic shielding treatment into patterns and bind it into a net; then bind the carbon fiber felt that has been bound into a net with the skeleton net that was cut in step S2.

2. The method for preparing an infrared broadband radar flexible camouflage carbon felt car cover according to claim 1, characterized in that, In step S1, the cleaning pretreatment refers to: first, treating the carbon fiber felt with heat and drying for 1 to 2 hours; then, removing impurities from the surface of the carbon fiber felt by solvent cleaning; and finally, drying.

3. The method for preparing an infrared broadband radar flexible camouflage carbon felt car cover according to claim 1, characterized in that, The surface layer of the carbon fiber felt is prepared at a concentration of 2~3 g / m 2 After uniformly spraying a saturated sodium chloride solution at a controlled spray density and allowing it to dry horizontally at room temperature for 5-10 minutes, apply a layer of 2-3 g / m² to the lower surface of the carbon fiber. 2 Apply a saturated sodium chloride solution evenly to the specified spray density. Allow it to dry horizontally at room temperature for 5-10 minutes. Then, place it in a cool, dark place for 144-240 hours. Rinse it 3-5 times with deionized water and store it in a dry, cool place until ready for use.

4. The method for preparing an infrared broadband radar flexible camouflage carbon felt car cover according to claim 1, characterized in that, In step S3: the infrared camouflage coating is dispersed for 10-20 minutes, and then the infrared camouflage coating is sprayed onto the surface of the carbon fiber felt. After the spraying is completed, place the carbon fiber felt horizontally in a clean and ventilated place. After the coating surface dries, fold it and store it in a dry and ventilated place to complete the infrared camouflage treatment process on the upper surface of the carbon fiber felt.

5. The method for preparing an infrared broadband radar flexible camouflage carbon felt car cover according to claim 1, characterized in that, In step S4: the carbon nanotube conductive coating is dispersed for 5-10 minutes, and then the conductive coating is sprayed onto the lower surface of the carbon fiber felt. After spraying, place the carbon fiber felt horizontally in a clean and ventilated place. After the coating surface dries, fold it and store it in a dry and ventilated place to complete the electromagnetic shielding treatment process on the lower surface of the carbon fiber felt.

6. A method for preparing an infrared broadband radar flexible camouflage carbon felt vehicle cover according to any one of claims 1, 4, and 5, characterized in that, Step S4 is performed sequentially 24 hours after step S3 is completed.

7. The method for preparing an infrared broadband radar flexible camouflage carbon felt vehicle cover according to claim 1, characterized in that, In step S5, the cutting of flowers refers to: placing the spliced ​​carbon fiber felt on a flower cutting machine; laying the carbon fiber felt flat, with 20 to 30 layers on each sheet, ensuring the edges are neat and the vertical error is no more than 5mm; and after stacking the carbon fiber felt, placing it neatly and parallel on the flower cutting machine corresponding to the flower pattern for cutting. The process of binding the net involves: laying the carbon fiber felt flat on the workbench, then laying the skeleton net flat on the carbon fiber felt and adjusting it to be even and flat; using binding thread for binding, the binding structure is diamond-shaped, the binding density is controlled at 25 to 35 knots per square meter, the knot type is self-tightening, each knot is tied 3 to 5 times, the direction of the thread is forward and backward, and it is tied tightly, leaving a knot length of 20mm to 30mm.

8. The method for preparing an infrared broadband radar flexible camouflage carbon felt car cover according to claim 1, characterized in that, In step S5, the edge binding refers to: aligning the carbon fiber felt and the skeleton mesh on both sides, and completely wrapping them inside the edge binding strip along with the edge ropes. The stitches should be even, without any skipped stitches or broken threads. The seam between the connecting loop rope and the skeleton mesh should be re-stitched 3-5 times, with the repeated stitches completely covering the length. The connecting loop ropes should not be missing, and the stitches should be flat and secure. The length and spacing of the connecting rings must be within the tolerance range. The length of the connecting ring rope is 200mm ± 20mm, and the spacing of the connecting ring ropes is 200mm ± 20mm. Make cuts of approximately 15-25mm depth at intervals of 150-250mm on the fabric strip to facilitate the production of the rope; When binding the edges, the edge cord joints should be sewn at the center of any side length, and sewing at the four corners is not allowed.

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