Multiband compatible stealth system

Abstract

The invention relates to the technical field of camouflage stealth equipment, and discloses a multiband compatible stealth system. The stealth system comprises a honeycomb wave-absorbing layer, a flame-retardant layer, a sponge layer, a photonic crystal layer and a visible light coating which are sequentially stacked together from the bottom layer to the surface layer. The flame-retardant layer is coated on the upper surface of the honeycomb wave-absorbing layer; the sponge layer is in equal-area fit with the flame-retardant layer by using a heat sealing process; the photonic crystal layer comprises base cloth and a photonic crystal coating electroplated on the surface of the base cloth, and the base cloth is attached to the sponge layer in an equal-area mode through a heat sealing technology; and the visible light coating is coated on the surface of the photonic crystal plating layer. The infrared-radar-laser compatible stealth camouflage function is achieved through the characteristics of low emissivity and high transmittance of the photonic crystal material, meanwhile, the light high-strength sponge material is loaded, the characteristics of a target heat source part are restrained, the infrared stealth function is enhanced, and in addition, on the premise that a low-emissivity metal material is not adopted, the infrared stealth function is achieved. The adverse effect of metal materials on color matching can be effectively avoided, and visible light compatibility is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of camouflage and stealth equipment, and in particular relates to a multi-band compatible stealth system. Background Art

[0002] With the development of target recognition technology, the working bands of target recognition equipment have covered multiple bands such as visible light, infrared, laser and radar. Therefore, camouflage stealth technology also needs to solve the problem of multi-band compatible stealth.

[0003] The basic principle of achieving target camouflage and invisibility is to make the target after camouflage and invisibility consistent with the surrounding environment. According to the Holtzmann formula W = ε·T 4 It can be seen that controlling the infrared characteristics of the target can be achieved by changing ε (emissivity) or T (apparent temperature). The existing technology often uses a large amount of metal materials with low emissivity when achieving infrared compatible stealth, that is, by reducing the emissivity ε to suppress the significant thermal radiation characteristics of the target, but metal 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, the prior art provides a visible light-infrared compatible stealth technology, which uses low-emissivity metal materials in combination with resins and coloring pigments to achieve visible light-thermal infrared compatible stealth performance. However, metal materials will destroy the radar stealth effect. The prior art also provides a visible light-near infrared-radar compatible camouflage net, which uses low-emissivity metal to construct a low-emissivity surface, and applies a visible light coating on the low-emissivity surface to achieve visible light-infrared stealth, and achieves radar compatible stealth performance through the camouflage net cut flower design. The above prior arts all have the problem of poor infrared and radar compatibility. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-band compatible stealth system, which realizes the infrared-radar-laser compatible stealth camouflage function through the low emissivity and high transmittance characteristics of photonic crystal materials, and at the same time loads lightweight and high-strength sponge materials to suppress the characteristics of the target heat source part 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 adjustment to achieve visible light compatibility.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a multi-band compatible stealth system. The stealth system comprises a honeycomb absorbing layer, a flame retardant layer, a sponge layer, a photonic crystal layer and a visible light coating layer stacked in sequence from the bottom layer to the surface layer.

[0008] As a possible implementation method, a flame retardant layer is coated on the upper surface of the honeycomb absorbing layer; the sponge layer is bonded to the flame retardant layer in an equal area by 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 in an equal area by a heat sealing process; and the visible light coating is coated on the surface of the photonic crystal coating.

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

[0010] As a possible implementation manner, the thickness of the flame retardant layer is 80 μm to 100 μm, the drying temperature is 80° C. to 100° C., and the drying time is 3 to 5 minutes.

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

[0012] As a possible implementation method, the sponge layer is pretreated in the following way to quickly reach internal and external thermal equilibrium:

[0013] Soaking the sponge layer in a saturated lithium chloride solution for a preset soaking time;

[0014] Drying the sponge layer adsorbed with the saturated lithium chloride solution according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the lithium chloride is retained to form a crystalline hydrate;

[0015] As a possible implementation method, the sponge layer is pretreated in the following way to quickly reach internal and external thermal equilibrium:

[0016] The sponge layer is immersed in a dispersion containing phase change microcapsules for a preset immersion time; the phase change temperature of the phase change microcapsules is 60° C. to 100° C.;

[0017] The sponge layer adsorbing the dispersion of phase change microcapsules is dried according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the phase change microcapsules are retained in the pore structure of the sponge layer.

[0018] As a possible implementation, the photonic crystal layer includes a first photonic crystal layer and a second photonic crystal layer in a direction from close to the visible light coating to far away from the visible light coating; wherein the first photonic crystal layer is composed of ZnS stacked on MgF 2The thickness of the first photonic crystal layer is 0.064 mm, 0.082 mm or 0.092 mm; the second photonic crystal layer is ZnS and Ge stacked on MgF 2 On the other hand, the thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm respectively.

[0019] As a 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; or,

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

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

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

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

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

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

[0026] The coating formula of the visible light coating is: 50 parts of solvent, 40 parts of polyurethane resin, 3 parts of dispersing aid, 5 parts of perylene black pigment, 8 parts of titanium dioxide pigment, 5 parts of iron yellow pigment and 4 parts of chrome green pigment are taken by mass and stirred and ground to prepare a coating for forming a 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 effects:

[0028] 1. The low emissivity performance of photonic crystals just includes two windows of 3-5μm and 8-14μm, and it has high transmittance in other bands, so it has almost no effect on laser and radar performance. The multi-band compatible stealth system provided by the present invention can produce low reflection effect for 1.06μm laser and 10.6μm laser through photonic crystal composition and structural design, thereby shortening the enemy's guidance distance and giving us sufficient reaction time to achieve the purpose of laser stealth protection.

[0029] 2. The low emissivity performance of photonic crystals just includes two windows of 3-5μm and 8-14μm, and it has high transmittance in other bands, so it has almost no effect on laser and radar performance. The multi-band compatible stealth system provided by the present invention can make the incident radar waves pass through the surface basically without changing the characteristics through the high transmittance of radar waves, so that the radar attenuation material (such as honeycomb structure) loaded in the lower layer can take effect to control its echo radar characteristics and avoid exposing the characteristics of the camouflaged target.

[0030] 3. The multi-band compatible stealth system provided by the present invention has high transmittance to radar waves, and can enable microwave equipment using the stealth system, such as radar systems, communication systems and other equipment, to work normally in a camouflaged state, with both offensive and defensive capabilities.

[0031] 4. The multi-band compatible stealth system provided by the present invention absorbs crystalline hydrates or phase-change microcapsules in the sponge, and when the temperature is too high (such as during the day, the temperature of the camouflaged target itself is greater than 60°C), it begins to lose water or undergo phase change to consume heat, reduce the heat radiated outward, and thus accelerate the effect of achieving internal and external thermal balance, so that the thermal image of the camouflaged target and the background tend to be consistent in a short time. At night, the temperature drops and the air humidity increases. The crystalline hydrate can continue to absorb water, and the phase-change microcapsules can also release heat. Both processes are exothermic processes. The camouflaged targets are mostly made of metal materials, which heat up and cool down quickly. When they start to cool down, they often cool down faster than the surrounding environment (mainly soil). At this time, a certain amount of thermal compensation is required to reduce its cooling speed, and always maintain the consistency of the thermal radiation characteristics of the camouflaged target and the surrounding environment. Therefore, the structural design of the present invention has a good temperature control effect and can enhance the infrared stealth performance.

[0032] 5. The multi-band compatible stealth system provided by the present invention uses a low-emissivity and 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 surface visible light (high covering power / rate in the visible light band), so the preparation of a dark green low-emissivity coating can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

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

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

[0036] Figure 3 The stealth system prepared in Comparative Example 1 of the present invention is applied to a certain device and an image is obtained by imaging with an infrared thermal imager;

[0037] Figure 4 This is an image obtained by using an infrared thermal imager when the stealth system prepared in Comparative Example 2 of the present invention is applied to a certain device.

[0038] Reference numerals

[0039] 1-honeycomb absorbing layer, 2-flame retardant layer, 3-sponge layer, 4-photonic crystal layer, 5-visible light coating. DETAILED DESCRIPTION

[0040] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

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

[0042] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers 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 mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0043] With the development of target recognition technology, the working bands of equipment used to identify targets have covered multiple bands such as 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 target after camouflage and stealth consistent with the surrounding environment. The existing technology often uses a large amount of metal materials with low emissivity when achieving infrared compatible stealth, but metal materials will cause a sharp drop in radar stealth performance, making it difficult to achieve compatibility with radar stealth performance, or the compatibility effect is poor.

[0044] In order to solve the above problems, the present invention provides a multi-band compatible stealth system, which realizes the infrared-radar-laser compatible stealth camouflage function by constructing low-emissivity and high-transmittance characteristics through photonic crystal materials, and at the same time loads lightweight and high-strength sponge materials to suppress the characteristics of the target heat source part 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 adjustment to achieve visible light compatibility.

[0045] See also Figure 1 The present invention provides a multi-band compatible stealth system, which comprises a honeycomb absorbing layer 1, a flame retardant layer 2, a sponge layer 3, a photonic crystal layer 4 and a visible light coating 5 stacked in sequence from the bottom layer to the surface layer.

[0046] As a possible implementation, see Figure 1 The flame retardant layer 2 is coated on the upper surface of the honeycomb absorbing layer 1; the sponge layer 3 is bonded to the flame retardant layer 2 in an equal area by a heat-sealing process; the 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 the sponge layer 3 in an equal area by a heat-sealing process; the visible light coating 5 is coated on the surface of the photonic crystal coating.

[0047] The advantages of the present invention are that the honeycomb absorbing layer has the characteristics of high transmittance and low reflection, can absorb radar waves, reduce the reflection of radar waves, and achieve 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 can play a heat insulation role after being processed, achieve the effect of infrared stealth, and at the same time can also reduce 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, and can absorb lasers of different bands to achieve a laser stealth effect; since the present invention does not use metal materials, the visible light coating can achieve a dark green color consistent with the surrounding environment, achieve compatibility with visible light, and further enhance the stealth effect.

[0048] As a possible implementation method, the density of the honeycomb absorbing layer is ≤40kg / m 3 , compression strength ≥1MPa, operating temperature is -40℃~50℃, for example, -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃, 50℃; honeycomb porosity ≥80%, thickness is 30mm~50mm, for example, 30mm, 35mm, 40mm, 45mm, 50mm; 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 made of aramid paper honeycomb and HYSFA series soft foam absorbing material, which is a flexible material composed of carbon-based absorber, soft polyurethane foam material, water-based polyurethane, curing agent and a small amount of additives.

[0050] In the present invention, the honeycomb absorbing layer has the characteristics of high transmittance and low reflection, and the honeycomb porosity ≥ 80% is conducive to the passage of radar waves, can absorb radar waves, reduce the reflection of radar waves, and achieve a good radar stealth effect.

[0051] As a possible implementation method, the thickness of the flame retardant layer is 80μm to 100μm, for example, 80μm, 85μm, 90μm, 95μm, 100μm; the drying temperature is 80℃ to 100℃, for example, 80℃, 85℃, 90℃, 95℃, 100℃; the drying time is 3 to 5 minutes, for example, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, 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, and the flame retardant material is a flame retardant blended with antimony oxide and bromine or a nitrogen-phosphorus flame retardant. The flame retardant layer has a good flame retardant effect, can protect the safety of stealth targets, and is suitable for complex environments.

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

[0054] For example, the sponge layer can be made of a sponge material with a brand name of HYSFA-XK04, and can be formed by bonding the sponge layer with the flame retardant layer in an equal area by using a heat-sealing process.

[0055] As a possible implementation method, the sponge layer is pretreated in the following way to quickly reach internal and external thermal equilibrium:

[0056] Soaking the sponge layer in a saturated lithium chloride solution for a preset soaking time;

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

[0058] The sponge layer adsorbed with the saturated lithium chloride solution is dried according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the lithium chloride is retained to form a crystalline hydrate.

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

[0060] The sponge layer is soaked in a saturated lithium chloride solution to absorb lithium chloride in the sponge. The free water in the sponge is evaporated by controlling the drying temperature and time, leaving lithium chloride to form a crystalline hydrate. At this time, the sponge layer can not only insulate but also dissipate heat, and has a good infrared stealth effect. Lithium chloride loses its crystal water (taking away heat) at high temperature of the equipment, and re-absorbs moisture at night to form a crystalline hydrate, so it has good circulation.

[0061] As another possible implementation method, the sponge layer is pretreated in the following manner to enable it to quickly reach internal and external thermal equilibrium:

[0062] Soaking the sponge layer in a dispersion containing phase change microcapsules for a preset soaking time; the phase change temperature of the phase change microcapsules is 60°C to 100°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 100°C;

[0063] As an example, the sponge layer has a thickness of 4 to 5 mm, and the preset soaking time in the dispersion containing the phase change microcapsules is 1 hour;

[0064] The sponge layer adsorbing the dispersion of phase change microcapsules is dried according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the phase change microcapsules are retained in the pore structure of the sponge layer.

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

[0066] The sponge layer is soaked with a dispersion containing phase change microcapsules. After the sponge layer fully absorbs (completely absorbs) the solution, the sponge layer is dried, and the phase change microcapsules remain in the sponge pore structure. At this time, the sponge layer can both insulate heat (that is, increase the difficulty of heat transfer) and consume the heat conducted, and has a good infrared stealth effect. Phase change microcapsules absorb heat at high temperatures and release heat when the temperature drops, and have good circulation.

[0067] In the present invention, after being processed in two different ways, the sponge layer can play a heat-insulating role and achieve the effect of infrared stealth, and at the same time can also reduce the reflectivity of radar waves.

[0068] As a possible implementation, the photonic crystal layer includes a first photonic crystal layer and a second photonic crystal layer in a direction from close to the visible light coating to far away from the visible light coating; wherein the first photonic crystal layer is composed of ZnS stacked on MgF 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 ZnS and Ge stacked on MgF 2 On the other hand, the thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm respectively.

[0069] As a 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; at this time, the infrared emissivity corresponding to 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 a 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; at this time, the infrared emissivity corresponding to 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 a 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; at this time, the infrared emissivity corresponding to 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 a 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; at this time, the infrared emissivity corresponding to 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 a 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; at this time, the infrared emissivity corresponding to 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 a 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; at this time, the infrared emissivity corresponding to 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 photonic crystal layer and the second photonic crystal layer can achieve the absorption effect of lasers with different wavelengths and realize the high-speed passage of radar waves.

[0076] As a possible implementation method, a coating process is used to coat a visible light coating on the surface of the photonic crystal coating, and the coating thickness of the visible light coating is 30 μm to 50 μm, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm; the drying temperature is 80° C. to 100° C., for example, 80° C., 85° C., 90° C., 95° C., 100° C.; the drying time is 1 min to 2 min, for example, 1.2 min, 1.4 min, 1.6 min, 1.8 min, 2 min;

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

[0078] Exemplarily, the method for preparing the visible light coating includes:

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

[0080] S2. The above raw materials were stirred at a speed of 800rmp until uniformly mixed;

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

[0082] S4. Apply a visible light coating on the surface of the photonic crystal coating using a coating process, with a coating thickness of 30 μm to 50 μm, a drying temperature of 80° C. to 100° C., and a drying time of 1 min to 2 min.

[0083] The traditional method of using metal materials with low emissivity is difficult to adjust the color of metal materials, especially to adjust them to dark green, because metals have very high L values ​​(up to 70 or more), and the L value of dark green is relatively low (generally around 35). Adding a large amount of metal materials will make it difficult to reduce the L value. However, the present invention does not require the use of metal materials, so the visible light coating can achieve a dark green color consistent with the surrounding environment, achieve compatibility with visible light, and further enhance the stealth effect.

[0084] To facilitate understanding of the technical solution of the present application, further description is given below in conjunction with specific embodiments.

[0085] Example 1

[0086] The flame retardant material is applied to the upper surface of the honeycomb absorbing layer by a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; the pretreated sponge layer is bonded to the flame retardant layer in equal areas by a heat sealing process, the sponge layer is 4 mm thick, and the brand is HYSFA-XK04; the first photonic crystal layer is electroplated on the upper surface of the base fabric, the first photonic crystal layer is 0.064 mm thick, and the second photonic crystal layer is applied on the first photonic crystal layer, the second photonic crystal layer is 0.069 mm thick; the base fabric and the sponge layer are bonded in equal areas by a heat sealing process; a visible light coating is prepared and coated on the surface of the photonic crystal coating, the formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0087] The stealth test was carried out using the stealth system prepared in this embodiment, and the test results are shown in Table 1:

[0088] Table 1 Test data obtained using the stealth system prepared in Example 1

[0089]

[0090]

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

[0092] Example 2

[0093] The flame retardant material is applied to the upper surface of the honeycomb absorbing layer by a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; the pretreated sponge layer is bonded to the flame retardant layer in equal areas by a heat sealing process, the sponge layer is 5 mm thick, and the brand is HYSFA-XK05; the first photonic crystal layer is electroplated on the upper surface of the base fabric, the first photonic crystal layer is 0.092 mm thick, and the second photonic crystal layer is applied on the first photonic crystal layer, the second photonic crystal layer is 0.069 mm thick; the base fabric and the sponge layer are bonded in equal areas by a heat sealing process; a visible light coating is prepared and coated on the surface of the photonic crystal coating, the formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0094] The stealth test was carried out using the stealth system prepared in this embodiment. The test results are shown in Table 2:

[0095] Table 2 Test data obtained using the stealth system prepared in Example 2

[0096]

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

[0098] Example 3

[0099] The flame retardant material is applied to the upper surface of the honeycomb absorbing layer by a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; the pretreated sponge layer is bonded to the flame retardant layer in equal areas by a heat sealing process, the sponge layer is 5 mm thick, and the brand is HYSFA-XK05; the first photonic crystal layer is electroplated on the upper surface of the base fabric, the first photonic crystal layer is 0.064 mm thick, and the second photonic crystal layer is applied on the first photonic crystal layer, the second photonic crystal layer is 0.069 mm thick; the base fabric and the sponge layer are bonded in equal areas by a heat sealing process; a visible light coating is prepared and coated on the surface of the photonic crystal coating, the formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0100] The stealth test was carried out using the stealth system prepared in this embodiment. The test results are shown in Table 3:

[0101] Table 3 Test data obtained using the stealth system prepared in Example 3

[0102]

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

[0104] See also Figure 2 , which is an image obtained by using an infrared thermal imager to image a device using the stealth system prepared in this embodiment. It can be seen from the figure that the camouflaged part has a thermal image feature that is almost consistent with the environment, and forms thermal image patches with different brightness, so that the thermal radiation feature of the camouflaged target is well integrated with the background.

[0105] Comparative Example 1

[0106] The flame retardant material is applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; the pretreated sponge layer is bonded to the flame retardant layer in an equal area using a heat sealing process, the sponge layer is 4 mm thick, and the brand is HYSFA-XK04; a visible light coating is prepared and coated on the surface of the sponge layer. The formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0107] The stealth test was carried out using the stealth system prepared in this embodiment. The test results are shown in Table 4:

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

[0109]

[0110] In this comparative example, no photonic crystal layer is added, so its infrared reflectivity can only be high reflectivity and has no laser absorption effect.

[0111] See also Figure 3 , is the stealth system prepared in this comparative example, compared with Example 3, it is found that Figure 3 The camouflaged part has thermal image features that are consistent with the background, but because there is no low-emissivity coating formed by photonic crystals, no patches of varying brightness are produced, and there is no thermal image segmentation effect. This shows that the low-emissivity feature brought by photonic crystals can produce a significant segmentation effect on the target thermal infrared image, that is, infrared patches of varying brightness; the darker the patch, the lower the infrared emissivity. In actual reconnaissance environments, thermal images with consistent features over a large area (i.e., no thermal segmentation effect) do not conform to the actual background features and are more likely to be discovered.

[0112] Comparative Example 2

[0113] A flame retardant material is applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; a first photonic crystal layer is electroplated on the upper surface of the base fabric, with a thickness of 0.064 mm, and a second photonic crystal layer is applied on the first photonic crystal layer, with a thickness of 0.069 mm; a heat sealing process is used to bond the base fabric and the honeycomb absorbing layer to equal areas; a visible light coating is prepared and coated on the surface of the photonic crystal coating, and the formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0114] The stealth test was carried out using the stealth system prepared in this embodiment. The test results are shown in Table 5:

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

[0116]

[0117] In this comparative example, no sponge layer is added, so the visible 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 light and dark can be seen on the surface of the equipment. This is the infrared image segmentation effect brought about by the low emissivity of the photonic crystal.

[0118] See also Figure 4 , is the stealth system prepared in this comparative example, compared with Example 3, Figure 4 The thermal image features of the camouflaged parts are obviously brighter than the background, but it can be seen that it has hot patches of varying brightness. The formation of the hot patches is due to the use of photonic crystals to obtain a low infrared emissivity coating; its thermal image is obviously brighter than the background environment because there is no sponge material to provide insulation and accelerate the internal and external thermal balance, so the camouflaged parts have high thermal radiation intensity and their thermal image features are obviously brighter than the background.

[0119] Comparative Example 3

[0120] The flame retardant material is applied to the upper surface of the honeycomb absorbing layer using a coating process, with a coating thickness of 80 μm, a drying temperature of 80°C, and a drying time of 5 minutes; the pretreated sponge layer is bonded to the flame retardant layer in equal areas using a heat sealing process, the sponge layer thickness is 5 mm, and the brand is HYSFA-XK05; a metal low-emissivity substrate is prepared, and the substrate and the sponge layer are bonded in equal areas using a heat sealing process; a visible light coating is prepared and coated on the surface of the substrate. The formula and preparation method of the visible light coating have been described above and will not be repeated here.

[0121] The stealth test was carried out using the stealth system prepared in the comparative example. The test results are shown in Table 6:

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

[0123]

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

[0125] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0126] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A multi-band compatible stealth system, characterized in that: The stealth system comprises a honeycomb wave-absorbing layer, a flame-retardant layer, a sponge layer, a photonic crystal layer and a visible light coating layer stacked in sequence from the bottom layer to the surface layer.

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 in equal area by 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 in equal area by 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 / m 3 , compression strength ≥1MPa, operating temperature is -40℃~50℃, honeycomb porosity ≥80%, thickness is 30mm~50mm, 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 80 μm to 100 μm, the drying temperature is 80° C. to 100° C., and the drying time is 3 to 5 minutes.

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

6. The multi-band compatible stealth system according to claim 1, characterized in that: The sponge layer is pre-treated as follows to quickly achieve internal and external thermal equilibrium: Soaking the sponge layer in a saturated lithium chloride solution for a preset soaking time; The sponge layer adsorbed with the saturated lithium chloride solution is dried according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the lithium chloride is retained to form a crystalline hydrate.

7. The multi-band compatible stealth system according to claim 1, characterized in that: The sponge layer is pre-treated as follows to quickly achieve internal and external thermal equilibrium: The sponge layer is immersed in a dispersion containing phase change microcapsules for a preset immersion time; the phase change temperature of the phase change microcapsules is 60° C. to 100° C.; The sponge layer adsorbing the dispersion of phase change microcapsules is dried according to a preset drying temperature and drying time, so that the free water in the sponge layer evaporates and the phase change microcapsules are retained 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 includes a first photonic crystal layer and a second photonic crystal layer in a direction from close to the visible light coating to far away from the visible light coating; wherein the first photonic crystal layer is composed of ZnS stacked on MgF 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 ZnS and Ge stacked in sequence on MgF 2 On the other hand, the thickness of the second photonic crystal layer is 0.069 mm or 0.226 mm respectively.

9. The multi-band compatible stealth system according to claim 8, characterized in that: 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; or, 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; 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 0.069 mm; or, 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; or, 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; 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.

10. The multi-band compatible stealth system according to claim 1, characterized in that: The coating thickness of the visible light coating is 30 μm to 50 μm, the drying temperature is 80° C. to 100° C., and the drying time is 1 min to 2 min; The coating formula of the visible light coating is as follows: 50 parts by mass of solvent, 40 parts by mass of polyurethane resin, 3 parts by mass of dispersing aid, 5 parts by mass of perylene black pigment, 8 parts by mass of titanium white pigment, 5 parts by mass of iron yellow pigment and 4 parts by mass of chrome green pigment are stirred and ground to prepare a coating for the visible light coating; The visible light coating obtained based on the coating material is a low-emissivity dark green coating.

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