Composite fiber wave-absorbing paper, wave-absorbing honeycomb structure material and preparation method thereof

Abstract

The application provides a kind of composite fiber wave-absorbing paper, wave-absorbing honeycomb structure material and preparation method thereof.The composite fiber wave-absorbing paper includes aramid paper and fiber felt, fiber felt is arranged on at least one surface of aramid paper, and fiber felt includes one or both of glass fiber and conductive fiber.In the application, glass fiber and / or conductive fiber as wave-absorbing agent are made into wave-absorbing felt and arranged on the surface of aramid paper to form a wave-absorbing layer, so that the content of wave-absorbing agent in the composite fiber wave-absorbing paper of the application is greatly increased, and the wave-absorbing effect is also obviously improved.In addition, the fibers are combined together in advance by fiber felt, and there is no need for additional impregnation or shower coating of wave-absorbing material, only need to be made into honeycomb structure, so as to avoid the problems of coating falling off and powder falling caused by existing impregnation or shower coating, and ensure the structural stability of the formed wave-absorbing honeycomb.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wave-absorbing materials, in particular to a composite fiber wave-absorbing paper, a wave-absorbing honeycomb structure material and a preparation method thereof. BACKGROUND

[0002] The wave-absorbing honeycomb structure material has been widely used in wave-absorbing structural parts due to its advantages of wave-absorbing, structure bearing, low density, high temperature resistance and good machinability. The existing wave-absorbing honeycomb preparation process mainly uses a hexagonal cell aramid paper honeycomb as a structural core material, and a wave-absorbing coating with electromagnetic wave loss capability is formed on the side wall of the honeycomb cell by impregnation or spray coating process to achieve electromagnetic wave attenuation. However, there are still many problems in the preparation process and performance: 1. The wave-absorbing coating mainly includes wave-absorbing agent particles, resin adhesive and additives, and the wave-absorbing agent particles cannot be added too much, otherwise it will easily cause the coating to crack; 2. The coating cannot be too thick, otherwise the coating will fall off and the powder will fall off during long-term use, which will seriously affect the wave-absorbing performance; 3. The introduction of the coating will inevitably cause a significant increase in the density of the honeycomb, increasing the fuel consumption of the stealth aircraft; 4. The method of impregnation or spray coating to form the wave-absorbing coating is time-consuming and inevitably causes environmental pollution; 5. The wave-absorbing performance is poor in designability, and most of the wave-absorbing performance is improved by gradient impregnation, but the controllability of different gradient impregnation heights is poor, and the performance repeatability decreases sharply with the increase of the gradient. Therefore, the wave-absorbing honeycomb structure material produced by the traditional impregnation process is increasingly difficult to meet the high-specification requirements of aviation equipment in performance and application, and finding new wave-absorbing agents based on the honeycomb structure and its structural design form and preparation method is the current research direction of the wave-absorbing honeycomb. SUMMARY

[0003] The main purpose of the present application is to provide a composite fiber wave-absorbing paper, a wave-absorbing honeycomb structure material and a preparation method thereof, so as to solve the problems of poor wave-absorbing performance and insufficient structural stability of the wave-absorbing honeycomb structure material in the prior art.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a composite fiber wave-absorbing paper is provided, which comprises aramid paper and fiber felt, the fiber felt is arranged on at least one surface of the aramid paper, and the fiber felt comprises one or both of glass fiber and conductive fiber.

[0005] Further, along the first direction of the paper surface of the aramid paper, N fiber felts are arranged on the surface of the aramid paper in sequence, and along the arrangement direction of the fiber felts, the mass ratio of the glass fiber to the conductive fiber in the fiber felts increases in sequence, preferably N = 2-10, preferably the N fiber felts cover the entire surface of the aramid paper, preferably the same fiber felts are symmetrically arranged on the two surfaces of the aramid paper, preferably the length of the fiber felt along the arrangement direction of the fiber felt is 4-30 mm, and preferably the aramid paper and the fiber felt are adhesively fixed.

[0006] Further, the content of the fiber in the fiber felt is 85-95%, preferably the mass ratio of the glass fiber to the conductive fiber in the fiber felt is 1:0.01-0.25, preferably the glass fiber includes one or both of E glass fiber and C glass fiber, and the conductive fiber includes one or more of graphene fiber, carbon fiber and silicon carbide fiber.

[0007] According to another aspect of the present application, a wave-absorbing honeycomb structure material is provided, and the honeycomb framework of the wave-absorbing honeycomb structure material is prepared from any one of the composite fiber wave-absorbing papers described above.

[0008] Further, the cells of the honeycomb framework extend along the first direction of the aramid paper, preferably the cross section of the cells of the honeycomb framework is a hexagon, the side length of the hexagon is 1.83-5.5 mm, and preferably the glue layer for bonding the composite fiber wave-absorbing paper in the honeycomb framework is a conductive carbon glue layer.

[0009] Further, the wave-absorbing honeycomb structure material further includes a resin wrapping layer, and the resin wrapping layer is arranged on the exposed surface of the honeycomb framework, preferably the resin wrapping layer contains phenolic resin.

[0010] According to still another aspect of the present application, a preparation method of a wave-absorbing honeycomb structure material is provided, and the preparation method includes the following steps: step S1, mixing fibers and water to obtain a fiber dispersion liquid, the fibers including glass fiber and / or conductive fiber; step S2, preparing a fiber felt by using the fiber dispersion liquid; step S3, arranging the fiber felt on at least one surface of an aramid paper to obtain a composite fiber wave-absorbing paper; and step S4, preparing the wave-absorbing honeycomb structure material by using the composite fiber wave-absorbing paper.

[0011] Further, the mass concentration ratio of the glass fibers and the conductive fibers in the N fiber dispersions prepared in step S1 is sequentially increased, and N fiber mats are prepared by dehydrating, cementing and drying the N fiber dispersions respectively in step S2, preferably the cementing agent used in the cementing comprises one or more of polyvinyl alcohol, styrene-acrylic emulsion and acrylic resin, preferably N = 2-10; step S3 comprises: on at least one surface of the aramid paper, the N fiber mats are pasted on the surface of the aramid paper along the first direction according to the trend that the mass concentration ratio of the glass fibers and the conductive fibers is sequentially increased, preferably the same fiber mat is symmetrically pasted on both surfaces of the aramid paper, to obtain a composite fiber wave-absorbing paper, preferably the N fiber mats cover the surface of the aramid paper, and preferably the length of the fiber mat along the arrangement direction of the fiber mat is 4-30 mm.

[0012] Further, in the fiber dispersion, the mass concentration ratio of the glass fibers and the conductive fibers is 1:0.01-0.25, preferably the length of the glass fibers and the conductive fibers is 2-12 mm, preferably the glass fibers comprise one or both of E glass fibers and C glass fibers, the conductive fibers comprise one or more of graphene fibers, carbon fibers and silicon carbide fibers, preferably the fiber dispersion further comprises a dispersing agent, preferably the mass content of the dispersing agent in the fiber dispersion is 0.02-0.3%, and the dispersing agent comprises one or both of hydroxyethyl cellulose and sodium carboxymethyl cellulose.

[0013] Further, step S4 comprises: step S41, gluing on part of the surface of the composite fiber wave-absorbing paper, and hot pressing and stretching and setting after sequentially laminating a plurality of composite fiber wave-absorbing papers, to obtain a honeycomb framework, preferably the glue used for gluing is conductive carbon glue, and preferably the hot pressing temperature is 100-200°C; step S42, sequentially dipping and curing the honeycomb framework, to obtain a wave-absorbing honeycomb structure material, preferably the glue solution used for dipping comprises phenolic resin, preferably the dipping treatment time is 10-30 min, preferably the curing treatment time is 1-2 h, and the temperature is 80-150°C, preferably the cell cross section of the honeycomb framework is hexagonal, and the cell side length is 1.83-5.5 mm.

[0014] The glass fiber and / or conductive fiber as the wave-absorbing agent are made into a wave-absorbing felt and arranged on the aramid paper to form a wave-absorbing layer. Compared with the prior art, the content of the wave-absorbing agent in the composite fiber wave-absorbing paper is greatly increased due to the low content of other components for bonding in the wave-absorbing felt, and the wave-absorbing effect is also obviously improved. In addition, the fibers are combined together in advance by the fiber felt, the structure of the fiber felt ensures that the fibers have high structural stability, and the prior composite of the fiber felt and the aramid paper in the form of the fiber felt belongs to two-dimensional composite, so it is more conducive to improving the stability of the composite. At the same time, when the composite fiber wave-absorbing paper is used to make a wave-absorbing honeycomb structure material, it is not necessary to additionally dip or spray the wave-absorbing material, but only needs to be made into a honeycomb structure, so the problems of coating peeling and powder falling caused by the prior dip or spray of the wave-absorbing material are avoided, and the structural stability of the formed wave-absorbing honeycomb is ensured. Moreover, the proportion of various fibers in the fiber felt and the arrangement mode of the fiber felt on the aramid paper are simple and controllable, so the composite fiber wave-absorbing paper of the application has good absorption effect on electromagnetic waves in a large frequency range, and can meet the wave-absorbing demand of various application scenarios. In summary, the composite fiber wave-absorbing paper is formed by arranging the wave-absorbing felt on the aramid paper, and the problems of insufficient content of the wave-absorbing agent and easy coating peeling and powder falling in the prior art are solved. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in their entirety. The embodiments illustrated in the drawings are illustrative of the present application and are not intended to limit the present application in any manner. In the drawings:

[0016] Figure 1 A structural schematic diagram of a wave-absorbing honeycomb structure material prepared according to an embodiment of the application is shown;

[0017] Figure 2 A top view of a wave-absorbing honeycomb structure material prepared according to an embodiment of the application is shown;

[0018] Figure 3 An enlarged view of A of a wave-absorbing honeycomb structure material prepared according to an embodiment of the application is shown; and

[0019] Figure 4 A structural schematic diagram of a composite fiber wave-absorbing paper prepared according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0020] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0022] As described in the background section of this application, the impregnation or coating processes used in existing microwave absorbing honeycomb fabrication processes can lead to insufficient microwave absorbing agent content in the absorbing layer and problems such as coating peeling and powder shedding. To solve the above problems, this application provides a composite fiber microwave absorbing paper, a microwave absorbing honeycomb structure material, and a method for preparing the same.

[0023] In a typical embodiment of this application, a composite fiber absorbing paper is provided, such as... Figure 4 As shown, the composite fiber absorbing paper includes aramid paper 10 and fiber felt 20. The fiber felt 20 is disposed on at least one surface of the aramid paper 10, and the fiber felt 20 includes one or both of glass fiber and conductive fiber.

[0024] This application uses glass fibers and / or conductive fibers as microwave absorbing agents to form a microwave absorbing mat, which is then deposited on the surface of aramid paper 10 to form a microwave absorbing layer. Compared to existing technologies, the microwave absorbing mat contains extremely low levels of other components used for bonding besides the microwave absorbing fibers, resulting in a significantly increased microwave absorbing agent content in the composite fiber microwave absorbing paper of this application, thereby significantly improving the microwave absorption effect. Furthermore, the fibers are pre-bonded by the fiber mat 20, whose structure ensures high structural stability. The pre-composite nature of the fiber mat 20 with the aramid paper 10 constitutes a two-dimensional composite, further enhancing the stability of the composite. Moreover, when using this composite fiber microwave absorbing paper to fabricate a microwave absorbing honeycomb structure material, it is not necessary to additionally impregnate or coat the microwave absorbing material; simply fabricating it into a honeycomb structure is sufficient. This avoids the coating peeling and powdering problems caused by existing impregnation or coating methods, ensuring the structural stability of the formed microwave absorbing honeycomb. Meanwhile, since the proportions of various fibers in the fiber felt 20 and the arrangement of the fiber felt 20 on the surface of the aramid paper 10 are simple and controllable, the composite fiber absorbing paper of this application has a good absorption effect on electromagnetic waves over a wide frequency range, which can meet the absorption requirements of various application scenarios. In summary, by setting the absorbing felt on the surface of the aramid paper 10 to form a composite fiber absorbing paper, the problems of insufficient absorbing agent content and easy coating peeling and powdering in the prior art are solved.

[0025] The arrangement of the fiber felt 20 on the surface of the aramid paper 10 in this application can be specifically designed according to different actual applications. In order to achieve a more ideal absorption effect for electromagnetic waves in a wider frequency range, this application adopts a gradient design for the fiber felt 20. In some embodiments, such as Figure 4As shown, preferably along the first direction of the paper surface of aramid paper 10, N fiber mats 20 are arranged on the surface of aramid paper 10 in turn, and along the arrangement direction of fiber mat 20, the mass ratio of glass fiber to conductive fiber in fiber mat 20 increases in turn. Compared with the prior art, the fiber mat 20 of the present application is easier to realize the above-mentioned gradual change of fiber content design, thereby improving the wave absorption frequency range of the composite fiber wave absorption paper 01. Preferably, N = 2-10, preferably N fiber mats 20 cover the entire surface of the aramid paper 10, preferably the same fiber mat 20 is symmetrically arranged on the two surfaces of the aramid paper 10, and preferably the length of the fiber mat 20 along the arrangement direction of the fiber mat 20 is 4-30 mm. Experiments show that the above-mentioned preferred design scheme can better improve the wave absorption frequency band width and wave absorption effect of the composite fiber wave absorption paper of the present application, and the fiber mat 20 with a width of 4-30 mm has better impedance performance, further improving the overall response of the material to incident electromagnetic waves.

[0026] In order to simplify the composite method of aramid paper 10 and fiber mat 20, the above-mentioned aramid paper 10 and fiber mat 20 are preferably bonded and fixed, and the adhesive used for bonding can be epoxy resin adhesive. In order to more flexibly adjust the wave absorption frequency range and wave absorption effect of the composite fiber wave absorption paper in actual application, the content of fibers in the fiber mat 20 is preferably 85-95%, and the mass ratio of glass fiber to conductive fiber is preferably 1:0.01-0.25, and the mass ratio of glass fiber to conductive fiber in the above-mentioned N fiber mats 20 can vary within the above-mentioned range. The glass fiber and conductive fiber used in the present application can be selected from the corresponding fibers commonly used in the present wave absorption. In order to improve the composite stability of the two and the structural stability of the formed fiber mat 20, the glass fiber preferably includes one or both of E glass fiber and C glass fiber, and the conductive fiber preferably includes one or more of graphene fiber, carbon fiber and silicon carbide fiber. In addition to the above-mentioned fibers, the above-mentioned fiber mat 20 is similar to the conventional fiber mat 20 in the prior art, and also contains adhesive for bonding fibers. The specific type of adhesive can adopt the type commonly used in fiber mat 20, which will not be described here.

[0027] In another typical embodiment of the present application, as shown in Figure 1 and Figure 2 a wave absorption honeycomb structure material is provided, and the honeycomb framework of the wave absorption honeycomb structure material is prepared from any one of the above-mentioned composite fiber wave absorption paper 01.

[0028] As described above, the composite fiber wave absorption paper 01 of the present application has the advantages of not easy to fall off, wide wave absorption frequency and high wave absorption efficiency. Using it as the honeycomb framework of the wave absorption honeycomb structure material can greatly improve the wave absorption effect and structural stability of the wave absorption honeycomb structure material, and further make it play a prominent role in many application scenarios. Among them, Figure 1In the uppermost wave-absorbing honeycomb structure material, each inclined surface and plane in the groove and each plane of the uppermost layer are provided with the fiber felt 20. Similarly, the inner surface of the hexagonal cell in the wave-absorbing honeycomb material is also provided with the fiber felt 20. The arrangement is shown in the top view Figure 2 as shown, Figure 2 In the wave-absorbing honeycomb structure material, the dashed line is the fold of the honeycomb, and the solid line intersecting the dashed line is the boundary line of each fiber felt 20. From Figure 2 It can be seen that the direction in which each fiber felt 20 extends is perpendicular to the direction in which the honeycomb cell of the wave-absorbing honeycomb structure material extends.

[0029] The structure of the wave-absorbing honeycomb structure material of the present application can be designed by those skilled in the art according to the actual application scene. In order to make the wave-absorbing honeycomb structure material have better wave-absorbing performance, it is preferred that the cell of the honeycomb framework extends in the first direction of the aramid paper 10, thereby facilitating the use of the gradually changing fiber felt 20 to achieve targeted and efficient absorption of electromagnetic waves of each frequency. It is preferred that the cross section of the cell of the honeycomb framework is hexagonal, and the side length of the hexagon is 1.83-5.5 mm.

[0030] In the present application, the glue for bonding the composite fiber wave-absorbing paper 01 can be selected from the commonly used glue in the art. In order to make the composite fiber wave-absorbing papers 01 not only more closely bonded together, but also electrically connected to each other, thereby further improving the wave-absorbing effect, for example, Figure 3 as shown, it is preferred that the glue layer for bonding the composite fiber wave-absorbing paper 01 in the honeycomb framework is a conductive carbon glue layer 02, specifically, for example, a carbon-containing epoxy resin glue.

[0031] In order to make the wave-absorbing honeycomb structure material have better structural stability, it is preferred that the wave-absorbing honeycomb structure material further comprises a resin wrapping layer, which is arranged on the exposed surface of the honeycomb framework. By arranging the resin wrapping layer, the resin framework is protected, the mechanical properties of the whole wave-absorbing honeycomb structure material are improved, and the loss of wave-absorbing fibers and structural damage caused by the contact of the composite fiber wave-absorbing paper 01 with the outside world are alleviated. Considering the wrapping effect and production cost, it is preferred that the resin wrapping layer contains phenolic resin.

[0032] In another typical embodiment of the present application, a preparation method of a wave-absorbing honeycomb structure material is provided, which can be referred to Figures 1 to 4 The preparation method comprises the following steps: step S1, mixing fibers and water to obtain a fiber dispersion liquid, the fibers comprising glass fibers and / or conductive fibers; step S2, preparing the fiber felt 20 by using the fiber dispersion liquid; step S3, arranging the fiber felt 20 on at least one surface of the aramid paper 10 to obtain the composite fiber wave-absorbing paper 01; and step S4, preparing the wave-absorbing honeycomb structure material by using the composite fiber wave-absorbing paper 01.

[0033] The wave-absorbing fibers are prepared into a fiber mat 20, and the fiber mat 20 is arranged on the surface of the aramid paper 10 to form a wave-absorbing layer. Compared with the method of arranging a wave-absorbing layer by impregnating a wave-absorbing agent in the prior art, the preparation method of the present application is simpler and more environmentally friendly. In addition, due to the extremely low content of other components used for bonding in the wave-absorbing mat in addition to the wave-absorbing fibers, the content of the wave-absorbing agent in the composite fiber wave-absorbing paper 01 is greatly increased, thereby significantly improving the wave-absorbing effect. In addition, by previously combining the fibers together through the fiber mat 20, the structure of the fiber mat 20 ensures that the fibers therein have high structural stability. Then, when the composite fiber wave-absorbing paper 01 is used to make a wave-absorbing honeycomb structure material, it is not necessary to additionally impregnate or coat the wave-absorbing material, but only needs to be made into a honeycomb structure, thereby avoiding the problems of coating falling off and powder falling caused by impregnation or coating in the prior art, and ensuring the structural stability of the formed wave-absorbing honeycomb. Moreover, since the proportion of various fibers in the fiber mat 20 and the arrangement method of the fiber mat 20 on the surface of the aramid paper 10 are simple and controllable, the composite fiber wave-absorbing paper 01 of the present application has good absorption effect on electromagnetic waves in a relatively large frequency range, and can meet the wave-absorbing needs of various application scenarios.

[0034] In some embodiments, the mass concentration ratio of the N kinds of fiber dispersions prepared in step S1 is sequentially increased, and N fiber mats 20 are prepared by dehydrating, cementing and drying the N kinds of fiber dispersions respectively in step S2, preferably the cementing agent used for cementing includes one or more of polyvinyl alcohol, styrene-acrylic emulsion and acrylic resin, and preferably N = 2-10; step S3 includes: on at least one surface of the aramid paper 10, the N fiber mats 20 are pasted on the surface of the aramid paper 10 in a trend of sequentially increasing the mass concentration ratio of the glass fibers and the conductive fibers in the first direction, preferably the same fiber mat 20 is symmetrically pasted on both surfaces of the aramid paper 10, to obtain the composite fiber wave-absorbing paper 01. By adjusting the fiber concentration in the fiber dispersion, the mass ratio of the glass fibers and the conductive fibers in the fiber mat 20 can be well controlled, and by pasting the plurality of fiber mats 20 on the surface of the aramid paper 10 in a trend of sequentially increasing the mass concentration ratio of the glass fibers and the conductive fibers, the fiber mat 20 with multiple mass ratios of fibers can be regularly distributed in the wave-absorbing honeycomb structure material, thereby having good absorption effect on electromagnetic waves in a relatively large frequency range, and improving the use range and effect of the wave-absorbing honeycomb structure material. In order to improve the utilization rate of the aramid paper 10 and the fiber mat 20, preferably the N fiber mats 20 cover the entire surface of the aramid paper 10, and preferably the length of the fiber mat 20 along the arrangement direction of the fiber mat 20 is 4-30 mm.

[0035] In order to make the wave-absorbing honeycomb structure material have better wave-absorbing effect, the mass concentration ratio of glass fiber and conductive fiber in the fiber dispersion liquid is preferably 1:0.01-0.25. The glass fiber and conductive fiber used in the present application can be selected from the corresponding fibers commonly used for wave absorption at present. In order to improve the stability of the combination of the two and the structural stability of the fiber mat 20 formed, the length of the glass fiber and the conductive fiber is preferably 2-12 mm. The glass fiber preferably includes one or both of E glass fiber and C glass fiber, and the conductive fiber includes one or more of graphene fiber, carbon fiber and silicon carbide fiber.

[0036] In the formation of the fiber dispersion liquid, in order to improve the dispersion uniformity of the fibers to optimize the dispersion uniformity of the fibers in the fiber mat 20 formed, the fiber dispersion liquid preferably further includes a dispersant. The mass content of the dispersant in the fiber dispersion liquid is preferably 0.02-0.3%, and the dispersant includes one or both of hydroxyethyl cellulose and sodium carboxymethyl cellulose. By adding the dispersant, the distribution of the wave-absorbing fibers in the dispersion liquid can be made more uniform, thereby avoiding the aggregation of the same fibers in the wave-absorbing mat, which leads to a decrease in wave-absorbing effect.

[0037] In some embodiments, the above step S4 includes: step S41, gluing on part of the surface of the composite fiber wave-absorbing paper 01, and hot pressing and stretching and setting after sequentially laminating a plurality of composite fiber wave-absorbing papers 01 to obtain a honeycomb framework; and step S42, sequentially dipping and curing the honeycomb framework to obtain a wave-absorbing honeycomb structure material. The gluing position in step S41 corresponds to the side wall parallel to the first direction of the cell. Figure 1 and Figure 2 As shown in Figure 1 , taking the uppermost wave-absorbing honeycomb structure material in Figure 2 as an example, the fiber mat 20 is arranged on each inclined surface and plane in the groove and each plane of the uppermost layer. Similarly, the inner surface of the hexagonal cell in the wave-absorbing honeycomb material is also provided with the fiber mat 20. The arrangement is as shown in the top view Figure 2 , wherein the dashed line is the crease of the honeycomb, and the solid line intersecting the dashed line is the boundary line of each fiber mat 20

[0038] The gluing method of the present application can use conventional methods in the art, preferably the glue used for gluing is conductive carbon glue, so that the composite fiber wave-absorbing paper 01 can be more closely bonded together, and an electrical connection can be formed between them. The temperature of the hot pressing is preferably 100-200°C to increase the bonding strength between adjacent composite fiber aramid paper 10. The honeycomb framework is sequentially impregnated with glue and cured, which can be wrapped to further improve the structural stability and performance of the wave-absorbing honeycomb structure material. In addition, the glue solution used for impregnation preferably includes phenolic resin, the impregnation time is preferably 10-30 min, the curing time is preferably 1-2 h, and the temperature is 80-150°C. The cell cross section of the honeycomb framework is preferably hexagonal, and the cell side length is 1.83-5.5 mm. The above-mentioned numerical ranges of other processes and structures can further improve the wave-absorbing effect and structural stability of the wave-absorbing honeycomb structure material, and further improve its overall performance.

[0039] According to the conventional method of making a honeycomb structure, the gluing position of step S41 corresponds to one side wall of the finally formed cell.

[0040] The beneficial effects of the present application are further illustrated by the following examples and comparative examples.

[0041] Example 1

[0042] 1. Add 3mm short carbon fibers (Japan Toray T700) and short glass fibers (Chongqing International Composite WCS2505-110) in a mass ratio of 0.03:1 to water containing a dispersant, hydroxyethyl cellulose, to disperse the fibers uniformly and stably in water to obtain a mixed fiber dispersion with a fiber concentration of 0.03wt%.

[0043] 2. Pour the mixed fiber dispersion obtained above into a paper sheet former, stir and disperse at a speed of 60rpm, then vacuum dehydrate, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber sheet formed on the forming net to a support plate for drying to obtain fiber mat 1.

[0044] 3. Change the mass ratio of added short carbon fibers and short glass fibers to 0.05:1 and 0.13:1 respectively; other preparation process conditions remain unchanged, repeat the above preparation steps to obtain fiber mats 2 and 3. The mass fraction of short carbon fibers and short glass fibers in fiber mats 1, 2 and 3 is shown in Table 1.

[0045] Table 1 Composition of fiber mat for Example 1

[0046] Fiber mat 1 Fiber mat 2 Fiber mat 3 Chopped carbon fiber content / wt% 2.65％ 4.35％ 10.57％ Chopped glass fiber content / wt% 88.50％ 86.96％ 81.30％

[0047] 4. Cut fiber felt 1 into 13mm wide strips, fiber felt 2 into 8mm wide strips, and fiber felt 3 into 6mm wide strips. Then, sequentially glue fiber felts 1, 2, and 3 onto one side of the aramid paper using epoxy resin adhesive (EAW2703 from Nanjing Yuyue Materials Technology Co., Ltd.) along the first direction. Next, glue fiber felt strips 1, 2, and 3 of the same width onto the other side of the aramid paper at corresponding positions and heights. Finally, perform a hot-pressing process (temperature: 120℃, time: 1h) to obtain the desired result. Figure 2 The composite fiber absorbing paper shown.

[0048] 5. Apply carbon-containing epoxy resin adhesive (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) to the above-mentioned carbon fiber gradient absorbing aramid paper with an adhesive application width of 2.75mm and an interval width of 8.25mm, wherein the adhesive is arranged in the first direction. Then, align the aramid paper and glue them together, and hot-press them at 120℃. Stretch the glued carbon fiber gradient absorbing aramid paper to form a standard hexagonal honeycomb grid and shape it. Then, immerse it in phenolic resin adhesive (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for impregnation treatment. Finally, cure the entire assembly in an oven at 80℃ for 2 hours. The cured product is as follows. Figure 3 The diagram shows a three-layer absorbing honeycomb structure material with a height of 27 mm along the hole direction and a hole grid side length of 2.75 mm.

[0049] Example 2

[0050] 1. Add 6mm long short carbon fiber (Toray T700 from Japan) and short glass fiber (WCS2505-110 from Chongqing International Composite Materials) to water containing dispersant hydroxyethyl cellulose at a mass ratio of 0.01:1 to dissolve the fibers and uniformly and stably disperse them in the water to obtain a mixed fiber dispersion with a fiber concentration of 0.05wt%.

[0051] 2. Pour the above-obtained mixed fiber dispersion into a paper forming machine, stir and disperse it at a speed of 60 rpm, dehydrate it under vacuum, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber blades formed on the forming wire to a support plate to dry, thus obtaining mixed fiber felt 1.

[0052] 3. The mass ratio of chopped carbon fiber and chopped glass fiber added was changed to 0.03:1, 0.05:1, and 0.09:1, respectively; other preparation process conditions remained unchanged, and the above preparation steps were repeated to obtain mixed fiber mats 2, 3, and 4. The mass fractions of chopped carbon fiber and chopped glass fiber in fiber mats 1, 2, 3, and 4 are shown in Table 2.

[0053] Table 2. Composition of fiber felt used in Example 2

[0054] Fiber mat 1 Fiber mat 2 Fiber mat 3 Fiber mat 4 Chopped carbon fiber content / wt% 0.90％ 2.65％ 4.35％ 7.56％ Chopped glass fiber content / wt% 90.09％ 88.50％ 86.96％ 84.03％

[0055] 4、Cut the mixed fiber mat 1 into a fiber mat strip with a width of 13 mm, cut the fiber mat 2 into a fiber mat strip with a width of 10 mm, cut the fiber mat 3 into a fiber mat strip with a width of 10 mm, cut the fiber mat 4 into a fiber mat strip with a width of 7 mm, and then sequentially adhere the mixed fiber mat strips 1, 2, 3, and 4 to one side of the aramid paper along the first direction using epoxy resin glue (Nanjing Yuyue Material Technology Co., Ltd. EAW2703), and then adhere the same width of fiber mat strips 1, 2, 3, and 4 to the other side of the aramid paper at the corresponding position and height, and then perform hot pressing (temperature: 120℃, time: 1h) treatment to obtain a composite fiber wave-absorbing paper.

[0056] 5、The above-mentioned carbon fiber gradually changing wave-absorbing aramid paper is coated with carbon-containing epoxy resin glue (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) with a glue coating width of 2.75 mm and a spacing width of 8.25 mm, wherein the glue arrangement direction is the first direction. Then the aramid papers are aligned and glued together, and hot pressing is performed at 120℃. The carbon fiber gradually changing wave-absorbing aramid paper adhered together is stretched to form standard hexagonal honeycomb cells and is shaped. Then it is immersed in a phenolic resin glue solution (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for glue dipping treatment. Finally, the whole is cured in an oven, and the curing temperature and time are 80℃ and 2h. After curing, a 4-layer wave-absorbing honeycomb structure material with a height of 40mm along the hole direction and a cell side length of 2.75mm is obtained.

[0057] Example 3

[0058] 1、The length of 3mm chopped carbon fiber (Japan Toray T700) and chopped glass fiber (Chongqing International Composite WCS2505-110) are added to water containing dispersant hydroxyethyl cellulose in a mass ratio of 0.03:1, so that the fibers are defibrated and uniformly and stably dispersed in water to obtain a mixed fiber dispersion with a fiber concentration of 0.03wt%;

[0059] 2、Pour the above-mentioned mixed fiber dispersion into a paper sheet former, stir and disperse at a speed of 60rpm, then vacuum dewater, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber sheet formed on the forming net to the support plate for drying to obtain mixed fiber mat 1.

[0060] 3、The mass ratio of the added chopped carbon fiber and chopped glass fiber is changed to 0.07:1, 0.09:1, 0.13:1, 0.15:1, and 0.20:1, respectively; other preparation process conditions remain unchanged, and the above-mentioned preparation steps are repeated to obtain mixed fiber mats 2, 3, 4, 5, and 6. The mass fraction of chopped carbon fiber and chopped glass fiber in fiber mats 1, 2, 3, 4, 5, and 6 is shown in Table 3.

[0061] Table 3 Ingredient table of fiber mat of Example 3

[0062]

[0063]

[0064] 4、Cut the mixed fiber mats 1, 2, 3, 4, 5 and 6 into fiber mat strips with a width of 5 mm respectively, and then sequentially adhere the mixed fiber mat strips 1, 2, 3, 4, 5 and 6 to one side of the aramid paper along the first direction using epoxy resin adhesive (Nanjing Yuyu Material Technology Co., Ltd. EAW2703), and then adhere the same width of fiber mat strips 1, 2, 3, 4, 5 and 6 to the other side of the aramid paper at the corresponding position and height, and then perform hot pressing (temperature: 120℃, time: 1h) treatment to obtain a composite fiber wave-absorbing paper.

[0065] 5、The above composite fiber wave-absorbing paper is coated with carbon-containing epoxy resin adhesive (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) with a glue coating width of 3.67 mm and an interval width of 8.25 mm, wherein the arrangement direction of the glue is the first direction. Then the aramid paper is aligned and glued together, and hot pressing is performed at 120℃. The composite fiber wave-absorbing paper adhered together is stretched to form a standard hexagonal honeycomb cell and is shaped. Then it is immersed in a phenolic resin adhesive solution (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for glue dipping treatment. Finally, the whole is cured in an oven, and the curing temperature and time are: 80℃, 2h. After curing, a 6-layer wave-absorbing honeycomb structure material with a height of 30mm along the hole direction and a cell side length of 3.67mm is obtained.

[0066] Example 4

[0067] 1、The length of 6mm short-cut graphene fibers (Hangzhou Gaoene Technology Co., Ltd. GX-GO-2) and short-cut glass fibers are added to water containing a dispersant, hydroxyethyl cellulose, in a mass ratio of 0.1:1, so that the fibers are defibrated and uniformly and stably dispersed in the water to obtain a mixed fiber dispersion liquid with a fiber concentration of 0.1wt%;

[0068] 2、Pour the above obtained mixed fiber dispersion liquid into a paper sheet former, stir and disperse at a speed of 60rpm, then vacuum dewater, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber sheet formed on the forming net to a support plate for drying to obtain a mixed fiber mat 1.

[0069] 3、The mass ratio of the added short-cut graphene fibers and short-cut glass fibers is changed to 0.15:1 and 0.25:1, respectively; other preparation process conditions remain unchanged, and the above preparation steps are repeated to obtain mixed fiber mats 2 and 3. The mass fractions of the short-cut graphene fibers and short-cut glass fibers in the fiber mats 1, 2 and 3 are shown in Table 4.

[0070] Table 4 Ingredient table of fiber mat for Example 4

[0071] Fiber mat 1 Fiber mat 2 Fiber mat 3 Chopped carbon fiber content / wt% 8.33％ 12.00％ 18.52％ Chopped glass fiber content / wt% 83.33％ 80.00％ 74.07％

[0072] 4、The mixed fiber mats 1, 2 and 3 are cut into fiber mat strips with widths of 15 mm, 8 mm and 8 mm, respectively, and then the mixed fiber mats 1, 2 and 3 are sequentially adhered to one side of the aramid paper along the first direction using epoxy resin adhesive (Nanjing Yuyu Material Technology Co., Ltd. EAW2703). Then, the same width of the fiber mat strips 1, 2 and 3 are adhered to the other side of the aramid paper at corresponding positions and heights. Then, hot pressing (temperature: 120°C, time: 1h) treatment is performed to obtain a graphene fiber gradient absorbing aramid paper.

[0073] 5、The above graphene fiber gradient absorbing aramid paper is coated with carbon-containing epoxy resin adhesive (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) with a width of 2.75 mm and a spacing width of 8.25 mm, wherein the arrangement direction of the adhesive is the first direction. Then, the aramid papers are aligned and glued together, and hot pressing is performed at 120°C. The graphene fiber gradient absorbing aramid papers adhered together are stretched to form standard hexagonal honeycomb cells and are shaped. Then, the adhesive treatment is performed by immersing the graphene fiber gradient absorbing aramid papers in a phenolic resin adhesive solution (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes. Finally, the whole is cured in an oven, and the curing temperature and time are 80°C and 2h, respectively. After curing, a 3-layer absorbing honeycomb structure material with a height of 31 mm along the hole direction and a cell side length of 2.75 mm is obtained.

[0074] Example 5

[0075] 1、The short-cut carbon fibers (Toray T700, Japan) and short-cut glass fibers (Chongqing International Composite WCS2505-110) with a length of 6 mm are added to water containing a dispersant hydroxyethyl cellulose at a mass ratio of 0.07:1 to make the fibers disperse and uniformly and stably disperse in water to obtain a mixed fiber dispersion with a fiber concentration of 0.1wt%. The short-cut carbon fiber content in the fiber mat 1 is 5.98wt%, and the short-cut glass fiber content is 85.47wt%.

[0076] 2、The above obtained mixed fiber dispersion is poured into a paper sheet former, stirred and dispersed at a speed of 60 rpm, then vacuum dewatered, then sprayed with polyvinyl alcohol adhesive, and finally the wet fiber sheet formed on the forming net is transferred to a support plate for drying to obtain the fiber mat 1.

[0077] 3Cut the mixed fiber mat 1 into a fiber mat strip with a width of 40 mm, and then use epoxy resin glue (Nanjing Yuyue Material Technology Co., Ltd. EAW2703) to paste it on one side of the aramid paper along the first direction. Then paste the same width of fiber mat 1 on the other side of the aramid paper at the corresponding position and height, and then perform hot pressing (temperature: 120℃, time: 1h) treatment to obtain a carbon fiber wave-absorbing aramid paper.

[0078] 4The above carbon fiber wave-absorbing aramid paper is coated with carbon-containing epoxy resin glue (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) with a width of 2.75 mm and a spacing width of 8.25 mm, wherein the arrangement direction of the glue is the first direction. Then align the aramid paper and glue it together, and perform hot pressing at 120℃. The carbon fiber wave-absorbing aramid paper glued together is stretched to form a standard hexagonal honeycomb cell and is shaped. Then immerse it in a phenolic resin glue solution (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for glue dipping treatment. Finally, the whole is cured in an oven, and the curing temperature and time are: 80℃, 2h. After curing, a single-layer wave-absorbing honeycomb structure material with a height of 40mm along the hole direction and a cell side length of 2.75mm is obtained.

[0079] Example 6

[0080] 1, Cut the length of 3mm short carbon fiber (Japan Toray T700) and short glass fiber (Chongqing International Composite WCS2505-110) into a ratio of 0.03:1 by mass fraction into water containing dispersant hydroxyethyl cellulose, so that the fibers are defibrated and uniformly and stably dispersed in water, to obtain a mixed fiber dispersion with a fiber concentration of 0.03wt%;

[0081] 2, Pour the mixed fiber dispersion obtained above into a paper sheet former, stir and disperse at a speed of 60rpm, then vacuum dewater, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber sheet formed on the forming net to the support plate for drying to obtain a mixed fiber mat 1.

[0082] 3, The mass ratio of the added short carbon fiber and short glass fiber is changed to 0.07:1, 0.09:1, 0.13:1, 0.15:1, and 0.20:1, respectively; other preparation process conditions remain unchanged, and the above preparation steps are repeated to obtain mixed fiber mats 2, 3, 4, 5 and 6.

[0083] 4. Cut the mixed fiber felts 1, 2, 3, 4, 5 and 6 into fiber felts with widths of 5mm, 5mm, 5mm, 5mm, 5mm and 5mm respectively. Then, in sequence, attach the mixed fiber felts 5, 4, 3, 1, 2 and 6 to one side of the aramid paper using epoxy resin adhesive (EAW2703 from Nanjing Yuyue Materials Technology Co., Ltd.) along the first direction. Then, attach fiber felt strips 5, 4, 3, 1, 2 and 6 of the same width to the other side of the aramid paper at the corresponding positions and heights. After that, perform hot pressing (temperature: 120℃, time: 1h) to obtain composite fiber absorbing paper. The mass fractions of chopped carbon fiber and chopped glass fiber in fiber felts 1-6 are shown in Table 5.

[0084] Table 5. Composition of the fiber felt used in Example 5

[0085]

[0086] 5. Apply conductive carbon adhesive (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) to the above-mentioned composite fiber absorbing paper with an adhesive application width of 3.67 mm and an interval width of 8.25 mm, wherein the adhesive is arranged in the first direction. Then, align the aramid paper and glue them together, and perform hot pressing at 120℃. Stretch the glued composite fiber absorbing paper to form a standard hexagonal honeycomb grid and shape it. Then, immerse it in phenolic resin adhesive (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for impregnation treatment. Finally, cure the entire structure in an oven at 80℃ for 2 hours. After curing, a 6-layer absorbing honeycomb structure material with a height of 30 mm along the hole direction and a grid side length of 3.67 mm is obtained.

[0087] Example 7

[0088] The difference from Example 1 is that the short-cut carbon fibers in Example 1 are replaced with short-cut graphene fibers of equal mass (Hangzhou Gaoxi Technology Co., Ltd. GX-GO-2).

[0089] Example 8

[0090] The difference from Example 1 is that the chopped carbon fibers in Example 1 are replaced with silicon carbide fibers of equal mass (Hunan Boxiang New Materials Co., Ltd.).

[0091] Example 9

[0092] 1. Add 6mm long short carbon fiber (Toray T700 from Japan) and short glass fiber (WCS2505-110 from Chongqing International Composite Materials) to water containing dispersant hydroxyethyl cellulose at a mass ratio of 0.01:1 to dissolve the fibers and uniformly and stably disperse them in the water to obtain a mixed fiber dispersion with a fiber concentration of 0.03wt%.

[0093] 2. Pour the above-obtained mixed fiber dispersion into a paper forming machine, stir and disperse it at a speed of 60 rpm, dehydrate it under vacuum, then spray polyvinyl alcohol adhesive, and finally transfer the wet fiber blades formed on the forming wire to a support plate to dry, thus obtaining mixed fiber felt 1.

[0094] 3. The mass ratio of chopped carbon fiber to chopped glass fiber was changed to 0.03:1, 0.05:1, 0.06:1, 0.07:1, 0.09:1, 0.13:1, 0.15:1, 0.17:1, and 0.2:1, respectively; other preparation process conditions remained unchanged, and the above preparation steps were repeated to obtain mixed fiber mats 2, 3, 4, 5, 6, 7, 8, 9, and 10. The mass fractions of chopped carbon fiber and chopped glass fiber in fiber mats 1-10 are shown in Table 6.

[0095] Table 6. Composition of fiber felt used in Example 6

[0096]

[0097] 4. Cut the mixed fiber felts 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 into 5mm wide fiber felt strips. Then, in sequence, glue the mixed fiber felt strips 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 to one side of the aramid paper along the first direction using epoxy resin adhesive (EAW2703 from Nanjing Yuyue Materials Technology Co., Ltd.). Then, glue fiber felt strips 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 of the same width to the other side of the aramid paper at the corresponding positions and heights. Finally, perform hot pressing (temperature: 120℃, time: 1h) to obtain composite fiber absorbing paper.

[0098] 5. Apply carbon-containing epoxy resin adhesive (Shenzhen Jinxin Technology Co., Ltd. GJC-WF050D) to the above-mentioned composite fiber absorbing paper with an adhesive application width of 3.67 mm and an interval width of 8.25 mm, wherein the adhesive is arranged in the first direction. Then, align the aramid paper and glue them together, and hot press at 120℃ to stretch the glued composite fiber absorbing paper to form a standard hexagonal honeycomb grid and shape it. Then, immerse it in phenolic resin adhesive (Nantong Sumitomo Co., Ltd. XT-10) for 20 minutes for impregnation treatment. Finally, cure the whole thing in an oven at 80℃ for 2 hours. After curing, a 10-layer absorbing honeycomb structure material with a height of 50 mm along the hole direction and a grid side length of 3.67 mm is obtained.

[0099] Comparative Example 1

[0100] Gradient absorbing honeycomb prepared by impregnation method: bare honeycomb density: 48 kg / m 3 The densities of the wall-mounted microwave absorbing agents containing microwave absorbing powder and carbon black after impregnation at different heights were 32 kg / m³.3 , 60 kg / m 3 , 78 kg / m 3 , the height is 15 mm, 8 mm and 8 mm respectively: the content of carbon powder in the wave-absorbing agent is 15 wt%.

[0101] Comparative Example 2

[0102] The uniform density wave-absorbing honeycomb prepared by the curtain coating method: the density of the bare honeycomb is 48 kg / m 3 ; the density of the wall-hanging wave-absorbing agent containing carbon black after the curtain coating is 32 kg / m 3 ; the content of carbon powder in the wave-absorbing agent is 15 wt%. For the direction along the cell, the curtain coating method can only prepare the wave-absorbing honeycomb with uniform density, and cannot prepare the wave-absorbing honeycomb with gradual change.

[0103] The wave-absorbing honeycomb structure material prepared in the examples and the wave-absorbing honeycomb in the comparative examples are cut into standard square samples with a size of 300 mm*300 mm along the cell direction, the reflectivity in the microwave frequency range of 1-18 GHz is tested according to the method of GJB 2038A-2011, and the results are shown in Table 7.

[0104] Table 7

[0105]

[0106] From the above description, it can be seen that the above-mentioned examples of the present application achieve the following technical effects:

[0107] The glass fibers and / or conductive fibers as the wave-absorbing agent are made into a wave-absorbing felt and arranged on the surface of aramid paper to form a wave-absorbing layer. Compared with the prior art, the content of the wave-absorbing agent in the composite fiber wave-absorbing paper of the present application is greatly increased due to the extremely low content of other components used for bonding in the wave-absorbing felt, and thus the wave-absorbing effect is also obviously improved. In addition, the fibers are combined together in advance by the fiber felt, and the structure of the fiber felt ensures that the fibers therein have high structural stability, and the prior composite of the fiber felt in the form of the fiber felt and the aramid paper belongs to two-dimensional composite, and thus it is more conducive to improving the stability of the composite. At the same time, when the composite fiber wave-absorbing paper is used to make a wave-absorbing honeycomb structure material, it is not necessary to additionally dip or spray the wave-absorbing material, but only needs to be made into a honeycomb structure, and thus the problems of coating peeling and powder falling caused by the prior dip or spray setting of the wave-absorbing material are avoided, and the structural stability of the formed wave-absorbing honeycomb is ensured. Moreover, since the proportion of various fibers in the fiber felt and the arrangement mode of the fiber felt on the surface of the aramid paper are simple and controllable, the composite fiber wave-absorbing paper of the present application has good absorption effect on electromagnetic waves in a relatively large frequency range, and can meet the wave-absorbing requirements of various application scenarios. In summary, by arranging the wave-absorbing felt on the surface of the aramid paper to form the composite fiber wave-absorbing paper, the problems of insufficient content of the wave-absorbing agent and easy coating peeling and powder falling in the prior art are solved.

[0108] The preferred embodiments of the present application have been described above, but the present application is not limited to the above, and various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite fiber wave-absorbing paper, characterized by, The composite fiber wave-absorbing paper comprises aramid paper (10) and fiber felt (20), the fiber felt (20) is arranged on at least one surface of the aramid paper (10), and the fiber felt (20) comprises one or both of glass fiber and conductive fiber; N fiber felts (20) are sequentially arranged on the surface of the aramid paper (10) along the first direction of the paper surface of the aramid paper (10), N=2-10, and the mass ratio of the glass fiber to the conductive fiber in the fiber felt (20) increases sequentially along the arrangement direction of the fiber felt (20), and the aramid paper (10) and the fiber felt (20) are adhesively fixed.

2. The composite fiber wave-absorbing paper according to claim 1, wherein, The N fiber felts (20) cover the entire surface of the aramid paper (10), the same fiber felt (20) is symmetrically arranged on the two surfaces of the aramid paper (10), and the length of the fiber felt (20) along the arrangement direction of the fiber felt (20) is 4-30 mm.

3. The composite fiber wave-absorbing paper according to claim 2, characterized in that, The content of the fiber in the fiber felt (20) is 85-95%.

4. The composite fiber wave-absorbing paper according to claim 3, characterized in that, The mass ratio of the glass fiber to the conductive fiber in the fiber felt (20) is 1:0.01-0.

25.

5. The composite fiber wave-absorbing paper according to claim 3, wherein, The glass fiber comprises one or both of E glass fiber and C glass fiber, and the conductive fiber comprises one or more of graphene fiber, carbon fiber and silicon carbide fiber.

6. A wave-absorbing honeycomb structural material, characterized by comprising: The honeycomb framework of the wave-absorbing honeycomb structure material is prepared from the composite fiber wave-absorbing paper (01) according to any one of claims 1 to 5.

7. The wave-absorbing honeycomb structure material according to claim 6, characterized by, The cells of the honeycomb framework extend along the first direction of the aramid paper (10).

8. The wave-absorbing honeycomb structure material according to claim 7, wherein The cross section of the cell of the honeycomb framework is a hexagon, and the side length of the hexagon is 1.83-5.5 mm.

9. The wave-absorbing honeycomb structure material according to claim 7, wherein The glue layer for bonding the composite fiber wave-absorbing paper (01) in the honeycomb framework is a conductive carbon glue layer (02).

10. The wave-absorbing honeycomb structure material according to claim 6, wherein The wave-absorbing honeycomb structure material further comprises a resin wrapping layer arranged on the exposed surface of the honeycomb framework.

11. The wave-absorbing honeycomb structure material according to claim 10, wherein The resin wrapping layer comprises phenolic resin.

12. A method for preparing a microwave absorbing honeycomb structure material, characterized in that, The preparation method comprises: Step S1, mixing fibers and water to obtain a fiber dispersion liquid, the fibers comprising glass fiber and / or conductive fiber; Step S2, preparing a fiber felt (20) by using the fiber dispersion liquid; Step S3, arranging the fiber felt (20) on at least one surface of aramid paper (10) to obtain a composite fiber wave-absorbing paper (01); Step S4, preparing the wave-absorbing honeycomb structure material by using the composite fiber wave-absorbing paper (01); In the step S1, N fiber dispersion liquids with sequentially increasing mass concentration ratios of the glass fiber to the conductive fiber are prepared, and in the step S2, N fiber felts (20) are prepared by respectively dehydrating, bonding and drying the N fiber dispersion liquids, and N=2-10; The step S3 comprises: N fiber mats (20) are pasted on the surface of the aramid paper (10) in a first direction on at least one surface of the aramid paper (10) in a trend of increasing mass concentration ratio of the glass fiber and the conductive fiber in turn, and the N fiber mats (20) cover the surface of the aramid paper (10).

13. The method of claim 12, wherein, The adhesive used for cementing comprises one or more of polyvinyl alcohol, styrene-acrylic emulsion and acrylic resin; Symmetrical fiber mats (20) are pasted on both surfaces of the aramid paper (10) to obtain the composite fiber wave-absorbing paper (01), and the length of the fiber mat (20) in the arrangement direction of the fiber mat (20) is 4-30 mm.

14. The method of claim 12, wherein, The mass concentration ratio of the glass fiber and the conductive fiber in the fiber dispersion liquid is 1:0.01-0.

25.

15. The method of claim 14, wherein, The length of the glass fiber and the conductive fiber is 2-12 mm.

16. The method of claim 14, wherein, The glass fiber comprises one or both of E glass fiber and C glass fiber, and the conductive fiber comprises one or more of graphene fiber, carbon fiber and silicon carbide fiber.

17. The method of claim 14, wherein, The fiber dispersion liquid further comprises a dispersant.

18. The method of claim 17, wherein, The mass content of the dispersant in the fiber dispersion liquid is 0.02-0.3%, and the dispersant comprises one or both of hydroxyethyl cellulose and sodium carboxymethyl cellulose.

19. The method of claim 13, wherein, The step S4 comprises: Step S41, gluing on part of the surface of the composite fiber wave-absorbing paper (01), and then hot pressing and stretching to obtain a honeycomb framework; Step S42, impregnating and curing the honeycomb framework to obtain the wave-absorbing honeycomb structure material.

20. The preparation method of claim 19, wherein, The glue used for gluing is conductive carbon glue, and the temperature of the hot pressing is 100-200 DEG C.

21. The preparation method of claim 19, wherein, The glue solution used for impregnating comprises phenolic resin, the impregnating treatment time is 10-30 min, and the curing treatment time is 1-2 h at a temperature of 80-150 DEG C.

22. The preparation method of claim 19, wherein, The cell cross section of the honeycomb framework is hexagonal, and the cell side length is 1.83-5.5 mm.

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