A multi-band compatible stealth system

Abstract

The application relates to the technical field of camouflage and stealth equipment, and discloses a multi-waveband compatible stealth system. The stealth system comprises, from the bottom layer to the surface layer, a honeycomb wave-absorbing layer, a fireproof layer, a sponge layer, a photonic crystal layer and a visible light coating which are stacked together in sequence; the fireproof layer is coated on the upper surface of the honeycomb wave-absorbing layer; the sponge layer is attached to the fireproof layer in an equal area by using a heat sealing process; the photonic crystal layer comprises a base cloth and a photonic crystal coating layer plated on the surface of the base cloth, and the base cloth is attached to the sponge layer in an equal area by using a heat sealing process; and the visible light coating is coated on the surface of the photonic crystal coating layer. The low-emissivity and high-transmittance characteristics of the photonic crystal material are used to realize the infrared-radar-laser compatible stealth camouflage function, light high-strength sponge material is loaded to suppress the target heat source part features and enhance the infrared stealth function, and in the premise of not using the low-emissivity metal material, the adverse influence of the metal material on color matching can be effectively avoided, and the visible light compatibility can be realized.

Description

Technical Field

[0001] This invention belongs to the field of camouflage and stealth equipment technology, and in particular relates to a multi-band compatible stealth system. Background Technology

[0002] With the development of target recognition technology, the operating bands of target recognition equipment now cover multiple bands, including visible light, infrared, laser, and radar. Therefore, camouflage and stealth technology also needs to address the challenge of multi-band compatible stealth.

[0003] The fundamental principle of achieving target camouflage is to make the camouflaged target blend in with its surroundings. According to the Holtzmann formula, W = ε·T 4 It is known that controlling the infrared characteristics of a target can be achieved by changing ε (emissivity) or T (apparent temperature). Existing technologies often use a large amount of low-emissivity metallic materials to achieve infrared-compatible stealth, that is, to suppress the target's significant thermal radiation characteristics by reducing the emissivity ε. However, metallic materials will cause a sharp decline in radar stealth performance, making it difficult to achieve compatibility between infrared and radar stealth performance, or the compatibility effect is poor.

[0004] For example, existing technologies provide a visible-infrared compatible stealth technology that utilizes low-emissivity metallic materials combined with resin and coloring pigments to achieve visible-infrared and thermal-infrared compatible stealth performance. However, the metallic materials compromise radar stealth effectiveness. Existing technologies also provide a visible-near-infrared and radar-compatible camouflage net, which uses a low-emissivity metal to construct a low-emissivity surface, coats this surface with a visible-light coating to achieve visible-infrared stealth, and uses a camouflage net with a patterned design to achieve radar-compatible stealth performance. All of these existing technologies suffer from poor infrared and radar compatibility. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-band compatible stealth system that utilizes the low emissivity and high transmittance characteristics of photonic crystal materials to achieve infrared-radar-laser compatible stealth camouflage functions. At the same time, it loads lightweight, high-strength sponge materials to suppress the characteristics of target heat source parts and enhance the infrared stealth function. Furthermore, without using metal materials with low emissivity, it can effectively avoid the adverse effects of metal materials on color matching, thereby achieving visible light compatibility.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a multi-band compatible stealth system, which consists of a honeycomb absorbing layer, a flame-retardant layer, a sponge layer, a photonic crystal layer, and a visible light coating layer stacked sequentially from the bottom layer to the surface.

[0008] As one possible implementation, a flame-retardant layer is coated on the upper surface of the honeycomb absorbing layer; a sponge layer is bonded to the flame-retardant layer with an equal area using a heat-sealing process; the photonic crystal layer includes a base fabric and a photonic crystal coating electroplated on the surface of the base fabric, the base fabric being bonded to the sponge layer with an equal area using a heat-sealing process; and a visible light coating is coated on the surface of the photonic crystal coating.

[0009] As one possible implementation, the density of the cellular absorbing layer is ≤40kg / m². 3 The compressive strength is ≥1MPa, the operating temperature is -40℃~50℃, the honeycomb porosity is ≥80%, the thickness is 30mm~50mm, and the pore size is 0.8mm~2.3mm.

[0010] As one possible implementation, the thickness of the flame-retardant layer is 80μm to 100μm, the drying temperature is 80℃ to 100℃, and the drying time is 3 to 5 minutes.

[0011] As one possible implementation, the pore size of the sponge layer is 40-50 PPI, the porosity is ≥70%, and the density is ≤20 kg / m³. 2 The thickness is 3mm to 5mm.

[0012] As one possible approach, the sponge layer can be pretreated to quickly achieve internal and external thermal equilibrium as follows:

[0013] The sponge layer is immersed in a saturated lithium chloride solution for a preset soaking time;

[0014] Dry the sponge layer containing a saturated lithium chloride solution at a preset drying temperature and time, so that the free water in the sponge layer evaporates and the lithium chloride is retained to form crystalline hydrates.

[0015] As one possible approach, the sponge layer can be pretreated to quickly achieve internal and external thermal equilibrium as follows:

[0016] The sponge layer is immersed in a dispersion containing phase change microcapsules for a preset soaking time; the phase change temperature of the phase change microcapsules is 60℃~100℃.

[0017] The sponge layer containing the phase change microcapsules is dried at a preset drying temperature and time to evaporate the free water in the sponge layer while retaining the phase change microcapsules in the pore structure of the sponge layer.

[0018] As one possible implementation, the photonic crystal layer comprises a first photonic crystal layer and a second photonic crystal layer sequentially from the direction closest to the visible light coating to the direction furthest from the visible light coating; wherein, the first photonic crystal layer is composed of ZnS stacked on MgF₂. 2The thickness of the first photonic crystal layer is 0.064 mm, 0.082 mm, or 0.092 mm; the second photonic crystal layer consists of ZnS and Ge stacked sequentially on MgF₂. 2 The thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm, respectively.

[0019] As one possible implementation, the photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.64 mm and a second photonic crystal layer with a thickness of 0.069 mm; or,

[0020] The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.069 mm; or,

[0021] The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.069 mm; or,

[0022] The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.64 mm and a second photonic crystal layer with a thickness of 0.226 mm; or,

[0023] The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.226 mm; or,

[0024] The photonic crystal layer includes a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.226 mm.

[0025] As one possible implementation method, the coating thickness of the visible light coating is 30μm to 50μm, the drying temperature is 80℃ to 100℃, and the drying time is 1min to 2min;

[0026] The coating formulation for the visible light coating is as follows: 50 parts by weight of solvent, 40 parts by weight of polyurethane resin, 3 parts by weight of dispersant, 5 parts by weight of perylene black pigment, 8 parts by weight of titanium dioxide pigment, 5 parts by weight of iron yellow pigment and 4 parts by weight of chrome green pigment are stirred and ground to prepare the visible light coating; the visible light coating obtained based on the coating is a low emissivity dark green coating.

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

[0028] 1. The low emissivity of photonic crystals falls within two windows: 3–5 μm and 8–14 μm. Furthermore, they exhibit high transmittance in other wavelength bands, thus having virtually no impact on laser and radar performance. The multi-band compatible stealth system provided by this invention, through the design of photonic crystal composition and structure, can achieve low reflection of 1.06 μm and 10.6 μm lasers, thereby shortening the enemy's guidance distance and providing sufficient reaction time to achieve laser stealth protection.

[0029] 2. The low emissivity of photonic crystals falls within two windows: 3–5 μm and 8–14 μm. Furthermore, they exhibit high transmittance in other wavebands, thus having virtually no impact on laser and radar performance. The multi-band compatible stealth system provided by this invention utilizes the high transmittance of radar waves to allow incident radar waves to pass through the surface with minimal alteration to their characteristics. This enables the underlying radar attenuation material (such as a honeycomb structure) to function, thereby controlling its echo radar characteristics and preventing the exposure of the camouflaged target's features.

[0030] 3. The multi-band compatible stealth system provided by this invention has high radar wave transmittance, which enables microwave equipment using this stealth system, such as radar systems and communication systems, to work normally in a camouflaged state, providing both offensive and defensive capabilities.

[0031] 4. The multi-band compatible stealth system provided by this invention uses crystalline hydrates or phase change microcapsules adsorbed in the sponge. When the temperature is too high (e.g., during the day, when the temperature of the camouflaged target is >60°C), it begins to lose water or undergo a phase change to consume heat, reducing the heat radiated outwards, thereby accelerating the achievement of internal and external thermal equilibrium. This allows the thermal image of the camouflaged target to become consistent with the background in a short time. At night, the temperature decreases and the air humidity increases. The crystalline hydrates can continue to adsorb water, and the phase change microcapsules can also release heat. Both of these processes are exothermic. The camouflaged target is mostly made of metal, which heats up and cools down quickly. When it begins to cool down, it often cools down faster than the surrounding environment (mainly the soil). At this time, a certain amount of thermal compensation is needed to reduce its cooling rate and maintain the consistency of the thermal radiation characteristics of the camouflaged target and the surrounding environment. Therefore, the structural design of this invention has a good temperature control effect and can enhance infrared stealth performance.

[0032] 5. The multi-band compatible stealth system provided by the present invention uses a low-emissivity, high-transmittance photonic crystal material to construct a low-emissivity surface. The photonic crystal material itself is colored and transparent, and has almost no effect on the visible light (high coverage / rate in the visible light band), so a dark green low-emissivity coating can be prepared. Attached Figure Description

[0033] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0034] Figure 1 A schematic diagram of a multi-band compatible stealth system structure provided in an embodiment of the present invention;

[0035] Figure 2 The image obtained by using an infrared thermal imager is an example of the stealth system prepared in Embodiment 3 of the present invention being applied to a certain device.

[0036] Figure 3 The image is obtained by using an infrared thermal imager to illustrate the application of the stealth system prepared in Comparative Example 1 of this invention to a certain device.

[0037] Figure 4 The image is obtained by using an infrared thermal imager to illustrate the application of the stealth system prepared in Comparative Example 2 of this invention to a certain device.

[0038] Figure Labels

[0039] 1-Honeycomb absorbing layer, 2-Flame retardant layer, 3-Sponge layer, 4-Photonic crystal layer, 5-Visible light coating. Detailed Implementation

[0040] To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0041] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0042] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0043] With the development of target recognition technology, the operating bands of equipment used for target identification now cover multiple bands, including visible light, infrared, laser, and radar. Therefore, camouflage and stealth also need to be compatible with multiple bands. The basic principle of achieving target camouflage and stealth is to make the camouflaged target blend in with its surrounding environment. Current technologies for achieving infrared-compatible stealth often use a large amount of low-emissivity metallic materials. However, metallic materials cause a sharp decline in radar stealth performance, making it difficult to achieve compatibility with radar stealth capabilities, or resulting in poor compatibility.

[0044] To address the aforementioned issues, this invention provides a multi-band compatible stealth system. It utilizes photonic crystal materials to construct a low emissivity and high transmittance characteristic to achieve infrared-radar-laser compatible stealth camouflage functionality. Simultaneously, it loads lightweight, high-strength sponge materials to suppress the characteristics of target heat source areas, enhancing the infrared stealth function. Furthermore, without employing low-emissivity metal materials, it effectively avoids the adverse effects of metal materials on color matching, thus achieving visible light compatibility.

[0045] See Figure 1 The present invention provides a multi-band compatible stealth system, which consists of a honeycomb absorbing layer 1, a flame retardant layer 2, a sponge layer 3, a photonic crystal layer 4, and a visible light coating layer 5, which are stacked together from bottom to top.

[0046] As one possible implementation, see Figure 1 Flame-retardant layer 2 is coated on the upper surface of honeycomb absorbing layer 1; sponge layer 3 is bonded to flame-retardant layer 2 with an equal area using a heat-sealing process; photonic crystal layer 4 includes a base fabric and a photonic crystal coating electroplated on the surface of the base fabric, and the base fabric is bonded to sponge layer 3 with an equal area using a heat-sealing process; visible light coating 5 is coated on the surface of photonic crystal coating.

[0047] The advantages of this invention are as follows: the honeycomb absorbing layer has the characteristics of high transmission and low reflection, which can absorb radar waves and reduce radar wave reflection, thus achieving a good radar stealth effect; the flame-retardant layer can protect the safety of the stealth target and is suitable for complex environments; the sponge layer, after treatment, can play a role in heat insulation, achieving an infrared stealth effect, while also reducing the reflectivity of radar waves; the photonic crystal layer is composed of a first photonic crystal layer and a second photonic crystal layer of different thicknesses, which can absorb lasers of different wavelengths, achieving a laser stealth effect; since this invention does not use metal materials, the visible light coating can achieve a deep green color consistent with the surrounding environment, achieving compatibility with visible light and further enhancing the stealth effect.

[0048] As one possible implementation, the density of the cellular absorbing layer is ≤40kg / m². 3 The compressive strength is ≥1MPa, and the operating temperature is -40℃~50℃, for example -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃, 50℃; the honeycomb porosity is ≥80%, the thickness is 30mm~50mm, for example 30mm, 35mm, 40mm, 45mm, 50mm; the pore size is 0.8mm~2.3mm, for example 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.3mm.

[0049] As an example, the honeycomb absorbing layer is a flexible material composed of aramid paper honeycomb, HYSFA series soft foam absorbing material, which is composed of carbon-based absorber, soft polyurethane foam material, waterborne polyurethane, curing agent and a small amount of additives.

[0050] In this invention, the honeycomb absorbing layer has the characteristics of high transmission and low reflection. The honeycomb porosity ≥80% helps radar waves to pass through, can absorb radar waves, reduce radar wave reflection, and achieve good radar stealth effect.

[0051] As one possible implementation, the thickness of the flame-retardant layer is 80μm to 100μm, for example, 80μm, 85μm, 90μm, 95μm, or 100μm; the drying temperature is 80℃ to 100℃, for example, 80℃, 85℃, 90℃, 95℃, or 100℃; and the drying time is 3 to 5 minutes, for example, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, or 5 minutes.

[0052] For example, the flame-retardant layer is formed by coating the upper surface of the honeycomb absorbing layer with a flame-retardant material, which is a blend of antimony oxide and bromide flame retardants or a nitrogen-phosphorus flame retardant. The flame-retardant layer has excellent flame-retardant effect, can protect the safety of stealth targets, and is suitable for complex environments.

[0053] As one possible implementation, the pore size of the sponge layer is 40 PPI to 50 PPI, for example, 40 PPI, 42 PPI, 44 PPI, 46 PPI, 48 PPI, or 50 PPI; the porosity is ≥70%, and the density is ≤20 kg / m³. 2 The thickness is 3mm to 5mm, for example, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0054] For example, the sponge layer can be made of sponge material with the grade HYSFA-XK04, and formed by heat sealing process and bonding it to the flame retardant layer with the same area.

[0055] As one possible approach, the sponge layer can be pretreated to quickly achieve internal and external thermal equilibrium as follows:

[0056] The sponge layer is immersed in a saturated lithium chloride solution for a preset soaking time;

[0057] As an example, the sponge layer is 4-5 mm thick, and the preset soaking time in the lithium chloride saturated solution is 1 hour;

[0058] The sponge layer containing a saturated lithium chloride solution is dried at a preset drying temperature and time to evaporate the free water in the sponge layer and retain the lithium chloride to form crystalline hydrates.

[0059] As an example, the preset drying temperature for drying the sponge layer adsorbed with lithium chloride saturated solution is 60°C, and the drying time is 2 hours.

[0060] The sponge layer is soaked in a saturated lithium chloride solution, which adsorbs the lithium chloride within the sponge. By controlling the drying temperature and time, the free water within the sponge evaporates, leaving the lithium chloride to form crystalline hydrates. At this point, the sponge layer not only provides insulation but also dissipates heat, resulting in excellent infrared stealth capabilities. The lithium chloride loses its water of crystallization (carrying away heat) at high temperatures and reabsorbs moisture at night to form crystalline hydrates, thus exhibiting good recyclability.

[0061] As another possible approach, the sponge layer can be pretreated to quickly achieve internal and external thermal equilibrium as follows:

[0062] The sponge layer is immersed in a dispersion containing phase change microcapsules for a preset soaking time; the phase change temperature of the phase change microcapsules is 60℃~100℃, for example, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 100℃.

[0063] As an example, the sponge layer is 4-5 mm thick, and the preset soaking time in the dispersion containing phase change microcapsules is 1 hour;

[0064] The sponge layer containing the phase change microcapsules is dried at a preset drying temperature and time to evaporate the free water in the sponge layer while retaining the phase change microcapsules in the pore structure of the sponge layer.

[0065] As an example, the preset drying temperature for drying the sponge layer of the dispersion adsorbed with phase change microcapsules is 60°C, and the drying time is 2 hours.

[0066] A sponge layer is immersed in a dispersion containing phase change microcapsules. After the sponge layer has fully absorbed (completely absorbed) the solution, it is dried, leaving the phase change microcapsules within the sponge's pore structure. At this point, the sponge layer serves both as insulation (i.e., increasing the difficulty of heat transfer) and as a means to dissipate conducted heat, resulting in excellent infrared stealth capabilities. The phase change microcapsules absorb heat at high temperatures and release heat upon cooling, exhibiting good circulation properties.

[0067] In this invention, the sponge layer, after being treated in two different ways, can both play a role in heat insulation, achieve infrared stealth, and reduce radar wave reflectivity.

[0068] As one possible implementation, the photonic crystal layer comprises a first photonic crystal layer and a second photonic crystal layer sequentially from the direction closest to the visible light coating to the direction furthest from the visible light coating; wherein, the first photonic crystal layer is composed of ZnS stacked on MgF₂. 2 The thickness of the first photonic crystal layer is 0.064 mm, 0.082 mm, or 0.092 mm; the second photonic crystal layer consists of ZnS and Ge stacked sequentially on MgF₂. 2 The thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm, respectively.

[0069] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.64 mm and a second photonic crystal layer with a thickness of 0.069 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.217, which produces a low reflection effect on 1.06 μm laser, and the laser reflectivity is 0.054.

[0070] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.069 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.284, which produces a low reflection effect on 1.06 μm laser, and the laser reflectivity is 0.054.

[0071] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.069 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.315, which produces a low reflection effect on 1.06 μm laser, and the laser reflectivity is 0.054.

[0072] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.64 mm and a second photonic crystal layer with a thickness of 0.226 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.217, which produces a low reflection effect on 10.6 μm laser, and the laser reflectivity is 0.008.

[0073] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.226 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.284, which produces a low reflection effect on 10.6 μm laser, and the laser reflectivity is 0.008.

[0074] As one possible implementation, the photonic crystal layer includes a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.226 mm; in this case, the infrared emissivity of the photonic crystal layer is 0.315, which produces a low reflection effect on 10.6 μm laser, and the laser reflectivity is 0.008.

[0075] The combination of different thicknesses of the first and second photonic crystal layers can achieve the absorption effect of lasers of different wavelengths and enable high-speed transmission of radar waves.

[0076] As one possible implementation, a visible light coating is applied to the surface of the photonic crystal coating using a coating process. The coating thickness is 30μm to 50μm, for example, 30μm, 35μm, 40μm, 45μm, or 50μm; the drying temperature is 80℃ to 100℃, for example, 80℃, 85℃, 90℃, 95℃, or 100℃; and the drying time is 1min to 2min, for example, 1.2min, 1.4min, 1.6min, 1.8min, or 2min.

[0077] The coating formulation for the visible light coating is as follows: 50 parts by weight of solvent, 40 parts by weight of polyurethane resin, 3 parts by weight of dispersant, 5 parts by weight of perylene black pigment, 8 parts by weight of titanium dioxide pigment, 5 parts by weight of iron yellow pigment and 4 parts by weight of chrome green pigment are stirred and ground to prepare the visible light coating; the visible light coating obtained based on the coating is a low emissivity dark green coating.

[0078] For example, a method for preparing a visible light coating includes:

[0079] S1. Take 50 parts solvent, 40 parts polyurethane resin, 3 parts dispersant, 5 parts perylene black pigment, 8 parts titanium dioxide pigment, 5 parts iron yellow pigment and 4 parts chrome green pigment by weight.

[0080] S2. Stir the above ingredients at 800 rpm until they are evenly mixed;

[0081] S3. Grind with a sand mill. The sand mill has a grinding media filling rate of 80%, the grinding media material is hard steel balls, the grinding media diameter is 1mm, the feed pressure is 1MPa, and the grinding is circulated until the fineness of the coating is ground to 40μm, then the grinding is stopped.

[0082] S4. Apply a visible light coating to the surface of the photonic crystal coating using a coating process. The coating thickness is 30μm to 50μm. The drying temperature is 80℃ to 100℃ and the drying time is 1min to 2min.

[0083] Traditional methods using low-emissivity metallic materials struggle to color-correct them, especially to achieve a deep green hue, because metallics have very high L-values ​​(above 70), while deep green has a lower L-value (generally around 35). Adding large amounts of metallic materials makes it difficult to lower the L-value. This invention, however, eliminates the need for metallic materials, allowing the visible light coating to achieve a deep green color that blends seamlessly with the surrounding environment, ensuring compatibility with visible light and further enhancing stealth capabilities.

[0084] To facilitate understanding of the technical solution of this application, further explanation will be provided below with reference to specific embodiments.

[0085] Example 1

[0086] Flame-retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and dried at 80°C for 5 minutes. A pre-treated sponge layer was then heat-sealed to the flame-retardant layer with an equal area; the sponge layer had a thickness of 4 mm and was of the HYSFA-XK04 brand. A first photonic crystal layer was electroplated onto the upper surface of the base fabric with a thickness of 0.064 mm. A second photonic crystal layer was applied onto the first photonic crystal layer with a thickness of 0.069 mm. The base fabric and sponge layer were then heat-sealed to achieve an equal area bond. A visible light coating was prepared and applied to the surface of the photonic crystal coating. The formulation and preparation method of the visible light coating have been described previously and will not be repeated here.

[0087] The stealth system prepared in this embodiment was used to conduct stealth tests, and the test results are shown in Table 1:

[0088] Table 1 shows the experimental data obtained using the stealth system prepared in Example 1.

[0089]

[0090]

[0091] As can be seen, this embodiment achieves a stealth effect compatible with visible light, laser, infrared, and radar.

[0092] Example 2

[0093] Flame-retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and dried at 80°C for 5 minutes. A pre-treated sponge layer was then heat-sealed to the flame-retardant layer with an equal area; the sponge layer had a thickness of 5 mm and was of the HYSFA-XK05 brand. A first photonic crystal layer was electroplated onto the upper surface of the base fabric with a thickness of 0.092 mm. A second photonic crystal layer was applied onto the first photonic crystal layer with a thickness of 0.069 mm. The base fabric and sponge layer were then heat-sealed to an equal area. A visible light coating was prepared and applied to the surface of the photonic crystal coating. The formulation and preparation method of the visible light coating have been described previously and will not be repeated here.

[0094] The stealth system prepared in this embodiment was used to conduct stealth tests, and the test results are shown in Table 2:

[0095] Table 2 shows the experimental data obtained using the stealth system prepared in Example 2.

[0096]

[0097] As can be seen, this embodiment also achieves a stealth effect compatible with visible light, laser, infrared, and radar.

[0098] Example 3

[0099] Flame-retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and dried at 80°C for 5 min. A pre-treated sponge layer was then heat-sealed to the flame-retardant layer with an equal area; the sponge layer had a thickness of 5 mm and was of the HYSFA-XK05 brand. A first photonic crystal layer was electroplated onto the upper surface of the base fabric with a thickness of 0.064 mm. A second photonic crystal layer was applied onto the first photonic crystal layer with a thickness of 0.069 mm. The base fabric and sponge layer were then heat-sealed to an equal area. A visible light coating was prepared and applied to the surface of the photonic crystal coating. The formulation and preparation method of the visible light coating have been described previously and will not be repeated here.

[0100] The stealth system prepared in this embodiment was used to conduct stealth tests, and the test results are shown in Table 3:

[0101] Table 3 shows the experimental data obtained using the stealth system prepared in Example 3.

[0102]

[0103] As can be seen, this embodiment also achieves a stealth effect compatible with visible light, laser, infrared, and radar.

[0104] See Figure 2 The image shown is an image obtained using an infrared thermal imager when the stealth system prepared in this embodiment is applied to a certain device. The image shows that the camouflaged area has thermal image features almost identical to the environment, and forms thermal image patches of varying brightness, resulting in good blending of the camouflaged target's thermal radiation characteristics with the background.

[0105] Comparative Example 1

[0106] Flame retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and the drying temperature was 80℃ for 5 min. The pretreated sponge layer was then bonded to the flame retardant layer with an equal area using a heat-sealing process. The sponge layer had a thickness of 4 mm and was of the HYSFA-XK04 grade. A visible light coating was prepared and applied to the surface of the sponge layer. The formulation and preparation method of the visible light coating have been described above and will not be repeated here.

[0107] The stealth system prepared in this embodiment was used to conduct stealth tests, and the test results are shown in Table 4:

[0108] Table 4 shows the experimental data obtained using the stealth system prepared in Comparative Example 1.

[0109]

[0110] Since no photonic crystal layer was added in this comparative example, its infrared reflectivity can only be high reflectivity, and it has no laser absorption effect.

[0111] See Figure 3 The stealth system prepared in this comparative example, compared with that in Example 3, shows that... Figure 3 The camouflaged areas exhibit thermal image features that closely match the background. However, due to the absence of a low-emissivity coating formed by photonic crystals, no patches of varying brightness are produced, thus lacking thermal image segmentation. This indicates that the low-emissivity features provided by photonic crystals can produce a significant segmentation effect in the target's thermal infrared image, creating infrared patches of varying brightness; darker patches correspond to lower infrared emissivity. In actual reconnaissance environments, large-area thermal images with uniform features (i.e., without thermal segmentation) do not match the actual background characteristics and have a higher probability of being detected.

[0112] Comparative Example 2

[0113] Flame-retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and the drying temperature was 80℃ for 5 min. A first photonic crystal layer was electroplated onto the upper surface of the base fabric, with a thickness of 0.064 mm. A second photonic crystal layer was applied onto the first photonic crystal layer, with a thickness of 0.069 mm. The base fabric and the honeycomb absorbing layer were bonded together with equal area using a heat-sealing process. A visible light coating was prepared and coated onto the surface of the photonic crystal coating. The formulation and preparation method of the visible light coating have been described above and will not be repeated here.

[0114] The stealth system prepared in this embodiment was used to conduct stealth tests, and the test results are shown in Table 5:

[0115] Table 5 shows the experimental data obtained using the stealth system prepared in Comparative Example 2.

[0116]

[0117] In this comparative example, no sponge layer was added, so the infrared stealth effect is worse than that of the stealth system with a sponge layer (i.e., the brightness is higher). However, due to the presence of the photonic crystal layer, patches of varying brightness can be seen on the surface of the equipment. This is the infrared image segmentation effect caused by the low emissivity of the photonic crystal.

[0118] See Figure 4 This is the stealth system prepared in this comparative example, compared with Example 3. Figure 4 The thermal image features of the camouflaged part are significantly brighter than the background, but it can be seen that it has thermal patches of varying brightness. The formation of the thermal patches is due to the use of a photonic crystal to obtain a low infrared emissivity coating. Its thermal image is significantly brighter than the background environment because there is no heat insulation and acceleration effect from the sponge material to achieve internal and external thermal balance. Therefore, the thermal radiation intensity of the camouflaged part is high, and its thermal image features are significantly brighter than the background.

[0119] Comparative Example 3

[0120] Flame-retardant material was applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, and the drying temperature was 80℃ for 5 min. The pretreated sponge layer was then heat-sealed to the flame-retardant layer with an equal area, the sponge layer having a thickness of 5 mm and a grade of HYSFA-XK05. A low-emissivity metal substrate was prepared and heat-sealed to the sponge layer with an equal area. A visible light coating was prepared and applied to the surface of the substrate. The formulation and preparation method of the visible light coating have been described above and will not be repeated here.

[0121] Stealth tests were conducted using the stealth system prepared in the comparative example, and the test results are shown in Table 6:

[0122] Table 6 shows the experimental data obtained using the stealth system prepared in Comparative Example 3.

[0123]

[0124] This comparative example uses a low-emissivity metallic material, which can have low emissivity characteristics, but it is not compatible with lasers and has low radar transmittance. The underlying radar wave attenuation material has virtually no effect, meaning it is not compatible with radar and is also not compatible with the dark green coating.

[0125] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, disclosure, and other materials. In this specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several of the functions listed in the specification. While certain measures are described in different embodiments, this does not mean that these measures cannot be combined to produce good results.

[0126] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the invention and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications fall within the scope of the invention and its equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A multi-band compatible stealth system, characterized in that, The stealth system consists of a honeycomb absorbing layer, a flame-retardant layer, a sponge layer, a photonic crystal layer, and a visible light coating layer, stacked sequentially from the bottom layer to the surface. The photonic crystal layer comprises a first photonic crystal layer and a second photonic crystal layer sequentially from the direction closest to the visible light coating to the direction furthest from the visible light coating; wherein, the first photonic crystal layer is composed of ZnS stacked on MgF₂. 2 The thickness of the first photonic crystal layer is 0.064 mm, 0.082 mm, or 0.092 mm; the second photonic crystal layer is composed of ZnS and Ge stacked sequentially on MgF₂. 2 The thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm, respectively. The visible light coating has a coating thickness of 30μm to 50μm, a drying temperature of 80℃ to 100℃, and a drying time of 1min to 2min. The visible light coating formulation is as follows: 50 parts by weight of solvent, 40 parts by weight of polyurethane resin, 3 parts by weight of dispersant, 5 parts by weight of perylene black pigment, 8 parts by weight of titanium dioxide pigment, 5 parts by weight of iron yellow pigment and 4 parts by weight of chrome green pigment are stirred and ground to prepare the visible light coating; the visible light coating obtained based on the coating is a low emissivity dark green coating.

2. The multi-band compatible stealth system according to claim 1, characterized in that, The flame-retardant layer is coated on the upper surface of the honeycomb absorbing layer; the sponge layer is bonded to the flame-retardant layer with an equal area using a heat-sealing process; the photonic crystal layer includes a base fabric and a photonic crystal coating electroplated on the surface of the base fabric, and the base fabric is bonded to the sponge layer with an equal area using a heat-sealing process; the visible light coating is coated on the surface of the photonic crystal coating.

3. The multi-band compatible stealth system according to claim 1, characterized in that, The density of the honeycomb absorbing layer is ≤40kg / m³ 3 The compressive strength is ≥1MPa, the operating temperature is -40℃~50℃, the honeycomb porosity is ≥80%, the thickness is 30mm~50mm, and the pore size is 0.8mm~2.3mm.

4. The multi-band compatible stealth system according to claim 1, characterized in that, The thickness of the flame-retardant layer is 80μm to 100μm, the drying temperature is 80℃ to 100℃, and the drying time is 3 to 5 minutes.

5. The multi-band compatible stealth system according to claim 1, characterized in that, The sponge layer has a pore size of 40 PPI to 50 PPI, a porosity of ≥70%, and a density of ≤20 kg / m³. 2 The thickness is 3mm to 5mm.

6. The multi-band compatible stealth system according to claim 1, characterized in that, The sponge layer is pretreated in the following way to quickly achieve internal and external thermal equilibrium: The sponge layer is immersed in a saturated lithium chloride solution for a preset soaking time; The sponge layer containing a saturated lithium chloride solution is dried at a preset drying temperature and time to evaporate the free water in the sponge layer and retain the lithium chloride to form crystalline hydrates.

7. The multi-band compatible stealth system according to claim 1, characterized in that, The sponge layer is pretreated in the following way to quickly achieve internal and external thermal equilibrium: The sponge layer is immersed in a dispersion containing phase change microcapsules for a preset soaking time; the phase change temperature of the phase change microcapsules is 60℃~100℃. The sponge layer containing the phase change microcapsules is dried at a preset drying temperature and time to evaporate the free water in the sponge layer while retaining the phase change microcapsules in the pore structure of the sponge layer.

8. The multi-band compatible stealth system according to claim 1, characterized in that, The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.064 mm and a second photonic crystal layer with a thickness of 0.069 mm; or, The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.069 mm; or, The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.069 mm; or, The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.064 mm and a second photonic crystal layer with a thickness of 0.226 mm; or, The photonic crystal layer comprises a first photonic crystal layer with a thickness of 0.082 mm and a second photonic crystal layer with a thickness of 0.226 mm; or, The photonic crystal layer includes a first photonic crystal layer with a thickness of 0.092 mm and a second photonic crystal layer with a thickness of 0.226 mm.

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