Resin truss structure reinforced foam wave-absorbing material and preparation method thereof

Abstract

The application provides a resin truss structure reinforced foam wave-absorbing material and a preparation method thereof. The wave-absorbing material comprises a glass steel panel, a wave-absorbing foam core material, a wave-absorbing resin column and a carbon fiber bottom plate. The upper layer is the glass steel panel, the lower layer is the carbon fiber bottom plate, the middle layer is provided with the wave-absorbing foam core material, and the wave-absorbing resin column in the form of a space truss structure is distributed in the wave-absorbing foam core material. The wave-absorbing resin column in the form of a space truss structure is formed by vacuum introduction and solidification. The size parameters and the space distribution parameters of the wave-absorbing resin column in the space truss structure are electromagnetically designed. The wave-absorbing foam core material is reinforced in the interlayer strength and the compression resistance, the foam sandwich wave-absorbing material is thinned and the low-frequency and wide-frequency wave-absorbing compatibility is realized. The technical problem that the existing structure type wave-absorbing material cannot effectively absorb low, medium and high frequency electromagnetic waves under the condition of limited thickness is solved. The manufacturing process of the application is simple, easy to control and suitable for large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wave-absorbing materials, in particular to a resin truss structure reinforced foam wave-absorbing material and a preparation method thereof. BACKGROUND

[0002] Structural wave-absorbing materials are multifunctional composite materials developed on the basis of advanced composite materials, which can not only bear load but also absorb waves. According to their structural forms, they can be divided into three types: laminated type, honeycomb sandwich type and foam sandwich type. The foam sandwich wave-absorbing material, as a typical lightweight structural material, is composed of a wave-absorbing foam core, a wave-transparent panel and a reflective bottom plate. The wave-transparent panel and the reflective bottom plate are adhered to the upper and lower surfaces of the wave-absorbing foam core, respectively, to form a whole. In order to obtain a wider frequency band of wave-absorbing performance, the existing technical means is to design the wave-absorbing foam core into a structure in which multiple single-layer wave-absorbing foam layers are stacked and adhered. However, with the increase in the number of single-layer wave-absorbing foam layers, the interlayer adhesion strength of the foam sandwich wave-absorbing material is low due to the cohesive force of the foam, which increases the risk of interlayer debonding in engineering applications and affects the use reliability of the foam sandwich wave-absorbing material. In order to enhance the interlayer strength of the foam sandwich composite material, the existing technology, such as a structural wave-absorbing composite material and a preparation method thereof provided in patent CN116423936, is to open slots on the upper and lower surfaces of the foam core and open through holes at the intersection of the surface slots in the thickness direction, and then introduce resin into the slots and holes through a vacuum introduction process. After the resin is cured, resin columns are formed in the thickness direction of the foam core, thereby enhancing the foam sandwich composite material.

[0003] As described above, the technical means of resin column reinforcement can solve the problems of weak interlayer adhesion strength and poor flat compression strength of the sandwich structure in which multiple single-layer wave-absorbing foam layers are stacked and adhered. However, the existing technology of designing the wave-absorbing foam core into a structure in which multiple single-layer wave-absorbing foam layers are stacked still cannot effectively solve the problem of wide-frequency radar wave absorption when the material thickness is limited, especially when the middle and high frequency wave absorption is difficult to consider the effective absorption of low frequency electromagnetic waves. SUMMARY

[0004] The main purpose of the present application is to provide a resin truss structure reinforced foam wave-absorbing material and a preparation method thereof, which can solve the technical problem that the existing foam sandwich wave-absorbing material cannot effectively absorb low, medium and high frequency waves when the thickness is limited, and can enhance the interlayer strength and compression resistance of the foam sandwich wave-absorbing material.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is: a resin truss structure reinforced foam wave-absorbing material, comprising a glass steel panel, a wave-absorbing foam core material, a wave-absorbing resin column and a carbon fiber bottom plate, wherein the upper layer is the glass steel panel, the lower layer is the carbon fiber bottom plate, the middle layer is provided with the wave-absorbing foam core material, and the wave-absorbing resin column in the form of a space truss structure is distributed in the wave-absorbing foam core material.

[0006] In the preferred scheme, the wave-absorbing foam core material is composed of 2-10 single foam layers which are compounded and stacked together, and the total thickness is 10-100 mm, and the single foam layer is any one of polymethacrylimide foam, polyurethane foam and epoxy resin foam.

[0007] In the preferred scheme, the wave-absorbing resin column is formed by uniformly mixing resin and absorbent and then curing, the resin is any one of vinyl resin, unsaturated resin and epoxy resin, and the absorbent is any one or a composite of multiple of short-cut carbon fiber, carbon black and graphene, and the addition amount of the absorbent is 0.05-3% of the total mass of the resin and the absorbent.

[0008] In the preferred scheme, the wave-absorbing resin column is in a space truss structure, the wave-absorbing resin column penetrates the wave-absorbing foam core material along three orthogonal directions at three orthogonal intersections, and the three planes include the planes in which the upper surface or the lower surface of the wave-absorbing foam core material is located; the wave-absorbing resin column obliquely penetrates the wave-absorbing foam core material to form a regular quadrangular pyramid structure, the oblique intersection starts at the orthogonal intersection of the wave-absorbing resin column on the upper surface of the wave-absorbing foam core material, that is, the top of the regular quadrangular pyramid structure, and the oblique intersection ends at the four orthogonal intersections of the wave-absorbing resin column on the lower surface of the wave-absorbing foam core material, that is, the four vertices of the square bottom surface of the regular quadrangular pyramid structure, thereby forming the space truss structure of the wave-absorbing resin column.

[0009] In the preferred scheme, the glass steel panel has a thickness of 0.2-1 mm and is composed of a fiber fabric reinforced resin composite material, the fiber fabric is any one of glass fiber fabric, quartz fiber fabric and aramid fiber fabric, and the resin is any one of epoxy resin and cyanate ester resin.

[0010] In the preferred scheme, the carbon fiber bottom plate has a thickness of 0.2-1 mm and is composed of a carbon fiber fabric reinforced resin composite material, and the resin is epoxy resin.

[0011] In the preferred scheme, the method comprises the following steps:

[0012] S1, orthogonal grooves are formed on the upper and lower surfaces of the wave-absorbing foam core material, and through holes are formed on the intersection of the orthogonal grooves on the upper and lower surfaces along the thickness direction, and oblique intersection is formed on the four orthogonal intersections of the orthogonal grooves on the lower surface of the wave-absorbing foam core material, and the holes in the wave-absorbing foam core material are in the form of a regular quadrangular prism structure, thereby obtaining the wave-absorbing foam core material with grooves and holes.

[0013] S2, adding an appropriate amount of absorbent and curing agent into the resin, stirring uniformly to obtain a wave-absorbing resin;

[0014] S3, sequentially laying the wave-absorbing foam core material with grooves and holes, a release cloth, a flow guide net on a flat mold, laying a resin pipe and a vacuum pipe, then sealing them with a vacuum bag film, injecting the wave-absorbing resin into the grooves and holes of the wave-absorbing foam core material by using a resin vacuum introduction process, keeping the vacuum state to complete the pre-curing of the wave-absorbing resin column, then performing post-curing after heating, and demolding after reducing to room temperature, to obtain a wave-absorbing foam core material reinforced by a resin truss structure;

[0015] S4, sequentially laying a carbon fiber bottom plate, the wave-absorbing foam core material reinforced by the resin truss structure and a glass steel panel on a flat mold, coating an epoxy resin adhesive between the layers to form a blank, and performing mold pressing to obtain the wave-absorbing foam sandwich material reinforced by the resin truss structure.

[0016] In the preferred solution, the groove width is 1-5 mm, the groove depth is 1-5 mm, the hole diameter is 1-5 mm, and the groove-hole spacing is 16-75 mm.

[0017] In the preferred solution, the viscosity of the wave-absorbing resin is controlled to be 150-800 mPa·s.

[0018] The resin truss structure reinforced wave-absorbing foam material and the preparation method thereof have the following beneficial effects: (1) the wave-absorbing resin used in the vacuum introduction process to reinforce the foam sandwich material is improved in design, and the size parameters of the wave-absorbing resin column formed by the vacuum introduction curing and the spatial distribution parameters in the wave-absorbing foam core material are electromagnetically designed, so that the foam sandwich wave-absorbing material is thinned and compatible with low-frequency and wide-frequency wave-absorbing while the interlayer strength of the wave-absorbing foam core material is enhanced; (2) the manufacturing process is simple and easy to control, and is suitable for large-scale production; (3) the spatial truss structure reinforced wave-absorbing foam material can adapt to the bending moment and shear force distribution in the structure, so that the foam wave-absorbing material has stronger structural stability and compression resistance, and the interlayer bonding strength of the foam sandwich wave-absorbing material is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0019] The application will be further described below in combination with the drawings and examples:

[0020] Figure 1 is a front view of an embodiment of the resin truss structure reinforced wave-absorbing foam material of the application;

[0021] Figure 2 is a top view of an embodiment of the resin truss structure reinforced wave-absorbing foam material of the application;

[0022] Figure 3This is a diagram of the spatial truss cell structure of the resin truss structure reinforced foam absorbing material of the present invention;

[0023] Figure 4 This is a front view of the space truss cell of the resin column of the resin truss structure reinforced foam absorbing material of the present invention;

[0024] Figure 5 This is a top view of the space truss cell of the resin column of the resin truss structure reinforced foam absorbing material of the present invention;

[0025] Figure 6 This is a comparison chart of the flat plate reflectivity curves of the foam absorbing material in Example 1 and Comparative Example 1 of the present invention.

[0026] In the diagram: 1. Fiberglass panel; 2. Microwave-absorbing foam core material; 3. Microwave-absorbing resin column; 4. Carbon fiber base plate. Detailed Implementation

[0027] like Figures 1-6 As shown, a resin truss structure reinforced foam absorbing material includes a fiberglass panel 1, a foam absorbing core 2, resin absorbing columns 3, and a carbon fiber base plate 4. The upper layer is the fiberglass panel 1, the lower layer is the carbon fiber base plate 4, and the middle layer is the foam absorbing core 2. The resin absorbing columns 3, which are in the form of a spatial truss structure, are distributed in the foam absorbing core 2. Electromagnetic optimization design was performed on the dimensional parameters of the vacuum-cured absorbing resin columns 3 and their spatial distribution parameters in the absorbing foam core material. This resulted in a regular periodic arrangement of the absorbing resin columns 3, which are embedded in the upper and lower surfaces of the absorbing foam core material 2 at 90° intervals. This periodic absorbing structural unit has a size smaller than the working wavelength and belongs to the category of absorbing superstructure. The periodic superstructure composed of the absorbing resin columns 3 and the absorbing foam core material 2 ensures that the constituent units generate corresponding absorption peaks. At the same time, the coupling effect between the units allows multiple absorption peaks to be superimposed. Meanwhile, the capacitive coupling effect caused by the standing wave between the unit layers causes the absorption peaks to shift to lower frequencies. This can solve the technical problem that existing structural absorbing materials cannot effectively absorb low, medium and high frequencies under thickness-limited conditions. Furthermore, the absorbing resin columns 3 in the form of a spatial truss structure enhance the structural stability of the foam absorbing material.

[0028] In the preferred embodiment, the microwave absorbing foam core material 2 is composed of 2-10 composite foam layers with a total thickness of 10-100 mm. The single foam layer can be any one of polymethacrylimide foam, polyurethane foam, or epoxy resin foam. Polymethacrylimide foam, polyurethane foam, and epoxy resin foam are all commercially available mature products with mature manufacturing processes, stable performance, and a wide variety of types. They can be selected according to the microwave absorption performance requirements. When the top and bottom single foam layers are ordinary blank foam, the microwave absorption performance is even better.

[0029] In the preferred embodiment, the wave-absorbing resin column 3 is formed by mixing resin and absorbent uniformly and then curing, the resin is any one of vinyl resin, unsaturated resin, and epoxy resin, the absorbent is any one or a combination of multiple of short-cut carbon fiber, carbon black, and graphene, and the amount of the absorbent added is 0.05-3% of the total mass of the resin and the absorbent. The resin used for the vacuum infusion process to enhance the foam sandwich material is improved by adding a light carbon-based absorbent to adjust the electromagnetic parameters of the resin to become a resin with wave-absorbing function.

[0030] In the preferred embodiment, the wave-absorbing resin column 3 has a space truss structure, and the wave-absorbing resin column 3 penetrates the wave-absorbing foam core 2 along three orthogonal directions at the three orthogonal intersections of the three planes, the three planes including the planes where the upper surface or the lower surface of the wave-absorbing foam core 2 is located; the wave-absorbing resin column 3 obliquely penetrates the wave-absorbing foam core 2 to form a regular quadrangular pyramid structure, the oblique starting point is the orthogonal intersection of the wave-absorbing resin column 3 on the upper surface of the wave-absorbing foam core 2, and the oblique ending points are located at the four orthogonal intersections of the wave-absorbing resin column 3 on the lower surface of the wave-absorbing foam core 2, forming a space truss structure of the wave-absorbing resin column.

[0031] The space truss structure of the wave-absorbing resin column 3 can enhance the structural stability and compression resistance of the wave-absorbing foam material, and can also enhance the interlayer bonding strength of the wave-absorbing material.

[0032] In the preferred embodiment, the glass steel panel 1 has a thickness of 0.2-1mm and is composed of a fiber fabric reinforced resin composite material, the fiber fabric is any one of glass fiber fabric, quartz fiber fabric, and aramid fiber fabric, and the resin is any one of epoxy resin and cyanate ester resin.

[0033] In the preferred embodiment, the carbon fiber bottom plate 4 has a thickness of 0.2-1mm and is composed of a carbon fiber fabric reinforced resin composite material, and the resin is epoxy resin.

[0034] In the preferred embodiment, the following steps are included:

[0035] S1, orthogonal grooves are opened on the upper and lower surfaces of the wave-absorbing foam core 2, and through holes are opened along the thickness direction at the intersections of the orthogonal grooves on the upper and lower surfaces, and oblique grooves are opened upward at the four orthogonal intersections of the orthogonal grooves on the lower surface of the wave-absorbing foam core 2, converging at one orthogonal intersection of the orthogonal grooves on the upper surface and opening four through holes, so that the oblique grooves inside the wave-absorbing foam core 2 form a regular quadrangular prism structure, obtaining the wave-absorbing foam core 2 with grooves and holes;

[0036] S2, an appropriate amount of absorbent and curing agent is added to the resin and stirred uniformly to obtain the wave-absorbing resin;

[0037] S3, sequentially lay the slotted and holed wave-absorbing foam core material 2, release cloth, flow guide net on the flat mold, lay resin pipe and vacuum pipe, then seal them with vacuum bag film, inject wave-absorbing resin into the slots and holes of the wave-absorbing foam core material by resin vacuum introduction process, keep vacuum state to complete pre-curing of the wave-absorbing resin column 3, after pre-curing, heat for post-curing, demold after cooling to room temperature, to obtain the resin truss structure reinforced wave-absorbing foam core material;

[0038] S4, sequentially lay the carbon fiber bottom plate 4, the resin truss structure reinforced wave-absorbing foam core material and the glass steel panel 1 on the flat mold, coat epoxy resin adhesive between layers to form a blank, and mold the blank to obtain the resin truss structure reinforced foam sandwich wave-absorbing material.

[0039] In the preferred embodiment, the slot width is 1-5 mm, the slot depth is 1-5 mm, the hole diameter is 1-5 mm, and the slot-hole spacing is 16-75 mm.

[0040] In the preferred embodiment, the viscosity of the wave-absorbing resin is controlled at 150-800 mPa·s.

[0041] Example 1

[0042] S1, select a polymethacrylimide wave-absorbing foam flat core material composed of four single foam layers compounded and bonded, the single foam layers on the upper and lower surfaces are blank foam layers, the total thickness is 25 mm, the orthogonal slots are opened on the upper and lower surfaces, the through holes are opened at the intersections of the orthogonal slots in the thickness direction, the four orthogonal intersections of the orthogonal slots on the lower surface are connected to the upper surface in a diagonal manner, and four through holes are opened at the intersection of the diagonal intersection on the upper surface, and a through hole is opened at the intersection of the diagonal intersection on the upper surface, so that the diagonal holes in the wave-absorbing foam core material form a regular quadrangular prism structure, the slot width is 3 mm, the slot depth is 3 mm, the hole diameter is 3 mm, and the slot-hole spacing is 75 mm, to obtain a slotted and holed wave-absorbing foam flat core material;

[0043] S2, add 0.8% of chopped carbon fiber absorbent and an appropriate amount of curing agent to the epoxy resin, stir uniformly, to obtain a wave-absorbing resin with a viscosity of 600 mPa·s;

[0044] S3, sequentially lay the slotted and holed wave-absorbing foam core material, release cloth, flow guide net on the flat mold, lay resin pipe and vacuum pipe, then seal them with vacuum bag film, inject wave-absorbing resin into the slots and holes of the wave-absorbing foam core material by resin vacuum introduction process, keep vacuum state to complete pre-curing of the wave-absorbing resin, after pre-curing, heat for post-curing, demold after cooling to room temperature, to obtain the resin truss structure reinforced wave-absorbing foam core material;

[0045] S4, lay the carbon fiber bottom plate with a thickness of 0.5 mm, the wave-absorbing foam core material reinforced by the resin truss structure, and the quartz fiber fabric reinforced epoxy resin glass steel panel with a thickness of 0.5 mm on the flat mold in sequence, coat the epoxy resin adhesive between the layers, and the coating adhesive amount is 250 g / m 2 , form a blank, and perform mold pressing forming on the blank to obtain the resin truss structure reinforced foam sandwich wave-absorbing material.

[0046] It is tested that the flat reflectivity curve of the prepared resin truss structure reinforced foam wave-absorbing material is as shown in Figure 6 .

[0047] Comparative Example 1

[0048] In comparison with Example 1, in the prior art, in the S1 step, no diagonal through holes are formed in the wave-absorbing foam core material, and in the S2 step, no chopped carbon fiber absorbent is added to the epoxy resin, and the remaining conditions and steps are consistent with those of Example 1, to obtain the foam sandwich wave-absorbing material with interlayer mechanical reinforcement.

[0049] It is tested that the flat reflectivity curve of the prepared foam sandwich wave-absorbing material with interlayer mechanical reinforcement is as shown in Figure 6 .

[0050] The test data of the comparative example and Example 1 are compared and listed in Table 1.

[0051] Table 1: Comparison of test data of Example 1 and Comparative Example 1

[0052]

[0053]

[0054] Example 2

[0055] S1, select a polyurethane wave-absorbing foam flat core material composed of five single foam layers, with a total thickness of 35 mm, form orthogonal distribution grooves on the upper and lower surfaces, and form through holes in the thickness direction at the intersection of the orthogonal grooves, form four through holes at the intersection of the orthogonal grooves on the lower surface of the wave-absorbing foam core material, and form four through holes at the intersection of the orthogonal grooves on the upper surface, so that the diagonal channels in the wave-absorbing foam core material form a regular quadrangular prism structure, the groove width is 2 mm, the groove depth is 2 mm, the hole diameter is 2 mm, and the groove-hole spacing is 30 mm, to obtain the grooved and holed wave-absorbing foam flat core material;

[0056] S2, add 0.5% of graphene absorbent and an appropriate amount of curing agent to the vinyl resin, stir uniformly, and obtain a wave-absorbing resin with a viscosity of 300 mPa·s;

[0057] S3, laying the slotted and holed polyurethane wave-absorbing foam flat core material, release cloth, flow guide net on the flat mold in turn, laying resin pipe and vacuum pipe, then sealing with vacuum bag film, injecting wave-absorbing resin into the slots and holes of the wave-absorbing foam core material by resin vacuum introduction process, keeping vacuum state to complete wave-absorbing resin pre-curing, pre-curing is completed, then heating for post-curing, demolding after reducing to room temperature, obtaining the resin truss structure reinforced wave-absorbing foam core material;

[0058] S4, laying the carbon fiber bottom plate with a thickness of 0.3mm, the resin truss structure reinforced wave-absorbing foam core material and the aramid fiber fabric reinforced cyanate ester resin glass steel panel with a thickness of 0.3mm on the flat mold in turn, coating epoxy resin adhesive between layers, the coating adhesive amount is 250g / m 2 , forming a blank, and molding the blank to obtain the resin truss structure reinforced foam sandwich wave-absorbing material.

[0059] The test data of the resin truss structure reinforced foam wave-absorbing material prepared is shown in Table 2.

[0060] Table 2 Test data of the resin truss structure reinforced foam wave-absorbing material prepared in Example 2

[0061]

[0062]

[0063] From the test data of Example 1 using the technology of the present application and Comparative Example 1 using the prior art, it can be seen that under the premise of the same panel, bottom plate, wave-absorbing foam core material, interlayer adhesive, the structural stability and low-frequency broadband wave-absorbing performance of the resin truss structure reinforced foam wave-absorbing material prepared by the present application are significantly better than those of the interlayer mechanically reinforced foam sandwich wave-absorbing material prepared by the prior art.

[0064] The above examples are only preferred technical solutions of the present application, and should not be regarded as limiting the present application, the protection scope of the present application should be the technical solutions recited in the claims, including the equivalent replacement solutions of the technical features recited in the claims as the protection scope. That is, the equivalent replacement improvement within this range is also within the protection scope of the present application.

Claims

1. A resin truss structure reinforced foam wave-absorbing material, characterized by: The application relates to a wave-absorbing resin column reinforced wave-absorbing foam core material, which comprises a glass fiber reinforced plastic panel (1), a wave-absorbing foam core material (2), a wave-absorbing resin column (3) and a carbon fiber bottom plate (4). The upper layer is the glass fiber reinforced plastic panel (1), the lower layer is the carbon fiber bottom plate (4), the middle layer is provided with the wave-absorbing foam core material (2), the wave-absorbing resin column (3) in a space truss structure form is distributed in the wave-absorbing foam core material (2), the wave-absorbing resin column (3) is obliquely intersected in the wave-absorbing foam core material (2) to form a regular quadrangular pyramid structure, the oblique intersection starting point is the orthogonal intersection of the wave-absorbing resin column (3) on the upper surface of the wave-absorbing foam core material (2), and the oblique intersection ending points are respectively located at the four orthogonal intersections of the wave-absorbing resin column (3) on the lower surface of the wave-absorbing foam core material (2), so that the space truss structure of the wave-absorbing resin column (3) is formed. The wave-absorbing resin column (3) is formed by mixing resin and absorbent uniformly and then solidifying, the absorbent is a composite of any one or more of short carbon fibers, carbon black and graphene, and the absorbent addition amount is 0.05-3% of the total mass of the resin and the absorbent.

2. The resin truss structure reinforced wave-absorbing foam material according to claim 1, characterized in that: The wave-absorbing foam core material (2) is composed of 2-10 single foam layers which are compounded and stacked, and the total thickness is 10-100 mm, and the single foam layer is any one of polymethacrylimide foam, polyurethane foam and epoxy resin foam.

3. The resin truss structure reinforced wave-absorbing foam material according to claim 1, characterized in that: The resin is any one of vinyl resin, unsaturated resin and epoxy resin.

4. The resin truss structure reinforced wave-absorbing foam material according to claim 1, characterized in that: The space truss structure of the wave-absorbing resin column (3), the wave-absorbing resin column (3) is respectively penetrated into the wave-absorbing foam core material (2) along three orthogonal directions at the three-plane orthogonal intersections, and the three planes include the planes where the upper surface or the lower surface of the wave-absorbing foam core material (2) is located.

5. The resin truss structure reinforced wave-absorbing foam material according to claim 1, characterized in that: The glass fiber reinforced plastic panel (1) has a thickness of 0.2-1 mm and is composed of fiber fabric reinforced resin composite material, the fiber fabric is any one of glass fiber fabric, quartz fiber fabric and aramid fiber fabric, and the resin is any one of epoxy resin and cyanate ester resin.

6. The resin truss structure reinforced wave-absorbing foam material according to claim 1, characterized in that the carbon fiber is The bottom plate (4) has a thickness of 0.2-1 mm and is composed of carbon fiber fabric reinforced resin composite material, and the resin is epoxy resin.

7. A method for preparing a resin truss structure reinforced foam microwave absorbing material according to any one of claims 1-6, characterized in that: The application further discloses a wave-absorbing resin column reinforced wave-absorbing foam core material manufacturing method, which comprises the following steps: S1, orthogonal distribution grooves are formed on the upper and lower surfaces of the wave-absorbing foam core material (2), and through holes are formed on the thickness direction of the orthogonal groove intersections on the upper and lower surfaces respectively, the four orthogonal intersections of the orthogonal grooves on the lower surface of the wave-absorbing foam core material (2) are obliquely intersected upwards, the oblique intersection ending points are respectively located at the four orthogonal intersections of the wave-absorbing resin column (3) on the lower surface of the wave-absorbing foam core material (2), the oblique intersection starting point is the orthogonal intersection of the wave-absorbing resin column (3) on the upper surface of the wave-absorbing foam core material (2), and the oblique intersection ending points are respectively located at the four orthogonal intersections of the wave-absorbing resin column (3) on the lower surface of the wave-absorbing foam core material (2), so that the oblique intersection holes in the wave-absorbing foam core material (2) form a regular quadrangular prism structure, and the wave-absorbing foam core material (2) with grooves and holes is obtained; S2, a proper amount of absorbent and curing agent is added into the resin and stirred uniformly to obtain the wave-absorbing resin; S3, the wave-absorbing foam core material with grooves and holes, a release cloth, a flow guide net are sequentially laid on a flat plate mold, a resin pipe and a vacuum pipe are laid, then the flat plate mold is sealed by a vacuum bag film, the wave-absorbing resin is injected into the grooves and holes of the wave-absorbing foam core material (2) by using a resin vacuum introduction process, the wave-absorbing resin column (3) is pre-solidified by keeping the vacuum state, the pre-solidification is completed, then post-solidification is carried out by heating, the flat plate mold is demoulded after the temperature is reduced to room temperature, and the wave-absorbing foam core material with the resin truss structure reinforcement is obtained. ​ S4, sequentially laying carbon fiber bottom plate (4), resin truss structure reinforced wave-absorbing foam core material and glass steel panel (1) on the flat mold, coating epoxy resin adhesive between layers to form a blank, and performing mold pressing forming on the blank to obtain a resin truss structure reinforced foam sandwich wave-absorbing material.

8. The method for preparing a resin truss structure reinforced foam microwave absorbing material according to claim 7, characterized in that: The slot width is 1-5 mm, the slot depth is 1-5 mm, the hole diameter is 1-5 mm, and the slot-hole spacing is 16-75 mm.

9. The method for preparing a resin truss structure reinforced foam microwave absorbing material according to claim 7, characterized in that: The wave-absorbing resin viscosity is controlled at 150-800 mPa·s.

Images