A high-strength absorbing paper and its preparation method and application

Abstract

The present invention relates to high-strength absorbing paper, its preparation method, and application. The method comprises: uniformly dispersing glass fiber and water to obtain a slurry; shaping the obtained slurry into glass fiber paper to obtain shaped glass fiber paper; mixing absorbent powder with water and stirring evenly to obtain a mixed liquid; pouring the obtained mixed liquid onto the shaped glass fiber paper and filtering it so that the absorbent powder is distributed within the glass fiber paper to obtain absorbent composite glass fiber paper; sizing the obtained absorbent composite glass fiber paper and composite it with a PET non-woven fabric, and then drying it to obtain the high-strength absorbing paper. During the preparation process, the distribution of the absorbent powder is adjusted by the pore distribution of the glass fiber paper, thereby regulating absorbing properties such as impedance matching and reflection loss. The preparation method is simple and low-cost, and the resulting absorbing paper is resistant to harsh environments and can absorb electromagnetic waves.

Description

Technical Field

[0001] The present invention relates to the technical field of glass fiber materials, and in particular to a high-strength absorbing paper and a preparation method and application thereof. Background Art

[0002] Absorbing materials are key materials in defense and civilian applications, including military stealth, microwave communications, and electromagnetic radiation protection. Based on the molding process, they can be divided into coated and structured absorbing materials. Coated absorbing materials are formed by mixing absorbers such as metal powder, alloy powder, carbon powder, ceramic powder, ferrite, conductive polymer, or modified powder, composite powder, with a binder and then coating the mixture on the target surface to form an absorbing coating. However, coated absorbing materials suffer from a series of issues, such as limited functionality, poor thermal stability, and easy shedding. These issues prevent them from meeting design requirements for both absorbing performance and appearance, limiting their widespread use in weaponry and civilian production. Film-coated absorbing materials can adapt to various shapes and scenarios, but current film-coated absorbing materials are complex to prepare, have low mechanical strength, and are difficult to disperse during the preparation process. Currently, film preparation is limited to laboratory research and cannot be applied in production. Summary of the Invention

[0003] In view of this, the main purpose of the present invention is to provide a high-strength absorbing paper and its preparation method and application. The technical problem to be solved is to cleverly use the filtering and interception principle to evenly and gradiently distribute the absorbing agent, which not only has the advantages of controllable impedance matching and adjustable absorbing performance, but also has the advantages of high strength.

[0004] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions. The present invention proposes a method for preparing high-strength absorbing paper, comprising the following steps:

[0005] S1: evenly dispersing glass fiber and water to obtain slurry;

[0006] S2: forming the slurry obtained in step S1 into glass fiber paper to obtain formed glass fiber paper;

[0007] S3: mixing the absorbent powder with water and stirring evenly to obtain a mixed solution;

[0008] S4: pouring the mixed solution obtained in step S3 onto the formed glass fiber paper obtained in step 2) and filtering it to distribute the absorbent powder inside the glass fiber paper to obtain the absorbent composite glass fiber paper;

[0009] S5: The absorbent composite glass fiber paper obtained in step S4 is sizing and compounded with a PET non-woven fabric, and then dried to obtain the high-strength absorbing paper.

[0010] Preferably, in the aforementioned method for preparing high-strength absorbing paper, in step S1, the mass ratio of the glass fiber to water is (1-80):10000; the fiber is selected from at least one of glass fiber, quartz fiber, ceramic fiber and organic fiber, and its wire diameter is ≤20μm.

[0011] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S1, the fibers are selected from at least two of glass fibers, quartz fibers, ceramic fibers and organic fibers, and the fiber diameters thereof are ≤20 μm.

[0012] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S1, the diameters of at least two fibers are the same or different.

[0013] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S2, a drying step is further included after the glass fiber paper forming step, and the drying temperature is 80-120°C.

[0014] Preferably, in the aforementioned method for preparing high-strength absorbing paper, step S2 further includes the steps of compounding, pressing and drying at least two formed fiberglass papers after the fiberglass paper forming step; the pressing load is 5-80N; and the drying temperature is 80-120°C.

[0015] Preferably, in the aforementioned method for preparing high-strength absorbing paper, in step S3, the absorber powder is a conductive or magnetic powder or fiber, which is selected from at least one of graphite powder, graphene, MoS2, MXene, ferrite, iron powder, cobalt powder and nickel powder.

[0016] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S3, the concentration of the absorber in the mixed solution is 0.001-30 g / L; and the mass ratio of the glass fiber to the absorber is 1:50-200:1.

[0017] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S5, the glue used for sizing is a thermosetting or thermoplastic polymer with a temperature resistance higher than 150°C; the non-woven fabric is 15-40g / m 2 PET non-woven fabric.

[0018] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S5, the sizing method includes one of spraying, filtration, soaking and filtration.

[0019] Preferably, in the above-mentioned method for preparing high-strength absorbing paper, in step S5, the amount of sizing applied is 2wt%-15wt%.

[0020] The objectives of the present invention and the technical problems solved therein can be further achieved by the following technical measures: The present invention provides a method for preparing high-strength absorbing paper, wherein the high-strength absorbing paper is a single-layer or multi-layer gradient paper having a thickness of 0.20 mm to 0.70 mm, a burst strength greater than or equal to 300 kPa, and an average reflection loss value of less than -10 dB between 2 and 18 GHz.

[0021] Preferably, in the aforementioned high-strength absorbing paper, the high-strength absorbing paper is prepared by the above method.

[0022] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures: The present invention proposes an isolation stealth material, which uses the aforementioned high-strength absorbing paper.

[0023] By means of the above technical solution, the high-strength absorbing paper provided by the present invention and its preparation method and application have at least the following advantages:

[0024] The high-strength absorbing paper of the present invention is constructed by adjusting the fiber diameter to form an absorbing paper with a gradient distribution of pore size. The filtering and interception mechanism is used to naturally distribute absorbent powders of different shapes and particle sizes in a gradient state. The absorbing paper is then prepared through processes such as adhesive curing to ensure that the absorbing paper is resistant to harsh environments, has adjustable pore size, and has excellent absorbing performance.

[0025] The high-strength absorbing paper of the present invention utilizes the filtering and interception principle to skillfully distribute the absorbing agent uniformly and in a gradient, thereby achieving controllability of the impedance matching and reflection loss of the membrane material.

[0026] The preparation method of the high-strength absorbing paper of the present invention is simple and low-cost, and the prepared absorbing paper has the performance of being resistant to harsh environments and capable of absorbing electromagnetic waves.

[0027] The high-strength absorbing paper of the present invention has a thickness of 0.20 mm to 0.70 mm, a bursting strength of greater than or equal to 300 kPa, and an average reflection loss value of less than -10 dB between 2 GHz and 18 GHz.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart for preparing the high-strength absorbing paper of the present invention;

[0030] Figure 2 This is a photo of the high-strength absorbing paper prepared in Example 1 of the present invention;

[0031] Figure 3 This is a cross-sectional SEM image of the high-strength absorbing paper prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0032] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following describes in detail, in conjunction with preferred embodiments, a high-strength absorbing paper, its preparation method, and its application, including its specific implementation, structure, features, and effectiveness. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0033] Unless otherwise specified, the materials and reagents mentioned below are all commercially available products familiar to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, technical or scientific terms used should have the same meanings as those of ordinary skill in the art. Where specific experimental procedures or conditions are not specified below, the procedures or conditions described in the literature in this field can be followed.

[0034] like Figure 1 As shown, some embodiments of the present invention provide a method for preparing high-strength absorbing paper, comprising the following steps:

[0035] 1) Glass fibers and water are placed in a dissociation mixer and uniformly dispersed to form a slurry. Specifically, the glass fibers may have the same diameter, or may be the same or different types of fibers with different diameters. The glass fibers have a diameter of 0.05-30 μm. If the diameter is greater than 30 μm, the fibers are too thick to intercept the absorbent. If the diameter is less than 0.05 μm, the glass fiber paper has poor air permeability, resulting in poor dispersion and aggregation of the absorbent powder. The fibers are selected from at least one of glass fibers, quartz fibers, ceramic fibers, and organic fibers, and may be of various sizes. Furthermore, the fibers may be selected from at least two of the following: glass fibers, quartz fibers, ceramic fibers, and organic fibers. The mass ratio of the glass fibers to water is (1-80):10,000. If the mass ratio is less than 1:10,000, the concentration is too low to form a continuous glass fiber paper. If the mass ratio is greater than 8:1000, the concentration is too high, resulting in glass fiber accumulation.

[0036] 2) The slurry obtained in step S1 is subjected to glass fiber paper forming to obtain formed glass fiber paper; the glass fiber paper forming can be formed on a straight wire, inclined wire or laboratory sheet papermaking machine, for example, it can be carried out on a wet forming papermaking machine. After the glass fiber paper forming step, a drying step is also included, or after the glass fiber paper forming step, at least two formed glass fiber papers are compounded, pressed and dried. The drying temperature is set to 80-120°C. If the temperature is lower than 80°C, the temperature is too low, resulting in an increase in drying time; if the temperature is higher than 120°C, the temperature is too high, resulting in a waste of energy. The load of the pressing can be set to 5-80N. When the load is greater than 80N, the pressure is too high, which can easily lead to damage of the glass fiber; when the load is less than 5N, the pressure is too low, and the water cannot be effectively squeezed out.

[0037] 3) Mixing and stirring the absorber powder with water to obtain a mixed solution, which is then set aside. The absorber powder can be a conductive or magnetic powder or fiber, including but not limited to graphite powder, graphene, MoS2, MXene, ferrite, iron powder, cobalt powder, nickel powder, or a mixture thereof. The absorber concentration in the mixed solution is 0.001-30 g / L, and the concentration is adjusted according to the density of the absorber. When the concentration is less than 0.001 g / L, the filtration interception time will be increased; when the concentration is greater than 30 g / L, the absorber will not be uniformly dispersed. Considering that the absorber includes not only high-density metal powder but also low-density single-layer graphene, the mass ratio of the glass fiber to the absorber can be set to 1:50 to 200:1. If the mass ratio is less than 1:50, the material impedance mismatch will occur, preventing electromagnetic waves from entering the material. If the ratio is greater than 200:1, the electromagnetic waves will not be absorbed by the material. To this end, the mass ratio of the glass fiber to the absorber is preferably 1:10-100:1. This optimization can achieve material impedance matching, so that electromagnetic waves can enter the material and are lost through the absorber distributed inside the material, thereby achieving a better absorbing effect.

[0038] 4) placing the formed glass fiber paper obtained in step 2) in a filtration funnel, extracting liquid from the mixed liquid obtained in step 4) according to the size of the filtration device, and filtering to distribute the absorbent powder inside the glass fiber paper, thereby obtaining an absorbent composite glass fiber paper; and intercepting cobalt trioxide and the like inside the glass fiber paper by filtration. In this way, the pore size can be controlled by utilizing different coarse and fine fiber ratios in the glass fiber paper, intercepting different absorbents and achieving a uniform or gradient distribution of the absorbent powder.

[0039] 5) The absorbent composite glass fiber paper obtained in step 4) is compounded with the non-woven fabric and sizing is performed, and then a drying treatment is performed at 100°C-180°C to obtain the high-strength absorbing paper. The reason for selecting the drying temperature of 100°C-180°C is mainly due to the properties of the adhesive. Considering the curing temperature, the glue used in the sizing is a thermosetting or thermoplastic polymer with a temperature resistance requirement higher than 150°C; for example, the glue can be a water-soluble resin adhesive, etc. The non-woven fabric is 20-40g / m 2 PET nonwoven fabric. If the weight is less than 20g / m 2 If the non-woven fabric is too thin, it will be easily deformed during the preparation process, resulting in uneven wrinkles on the paper; if the weight is greater than 40g / m 2 If the non-woven fabric is too thick and has poor air permeability, it will be difficult to form the paper. The sizing method includes spraying, filtration, or soaking and filtration. The sizing amount is controlled between 2wt% and 15wt% by controlling the adhesive concentration and sizing time. If the sizing amount is less than 2wt%, the adhesive is too little, resulting in low strength of the absorbing paper. If the sizing amount is greater than 15wt%, the sizing amount is too high, resulting in high hardness and poor workability.

[0040] It should be noted here that the high-strength absorbing paper refers to absorbing paper with a bursting strength greater than or equal to 300 kPa.

[0041] Some embodiments of the present invention further provide a high-strength absorbing paper having a thickness ranging from 0.20 mm to 0.70 mm, a bursting strength greater than or equal to 300 kPa, and an average reflection loss value between 2 and 18 GHz less than -10 dB; the high-strength absorbing paper is produced by the above method.

[0042] Some embodiments of the present invention also provide an isolation stealth material using the aforementioned high-strength absorbing paper. This isolation stealth material can be used for concealing buildings and vehicles in the military, as well as for protecting buildings or electronic equipment from electromagnetic interference in the civilian sector. To improve service life and meet tooling requirements, the high-strength absorbing paper has a thickness between 0.20 mm and 0.70 mm, a burst strength greater than or equal to 300 kPa, and an average reflection loss value of less than -10 dB between 2 and 18 GHz.

[0043] The present invention is further described below with reference to specific embodiments.

[0044] Example 1

[0045] This embodiment provides a method for preparing high-strength absorbing paper, comprising the following steps:

[0046] 1) Mix 3 g of 2 μm alkali-free glass fiber with 6 L of water and disperse evenly to obtain a slurry;

[0047] 2) forming the slurry obtained in step 1) on a sheet-making machine to obtain formed glass fiber paper; pressing the obtained formed glass fiber paper at 20N, and then drying it in a drying oven at 100°C for 2 minutes to obtain glass fiber paper;

[0048] 3) Mix 0.1 g of graphite powder (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) with 1.1 L of water, stir well, and obtain a mixed solution for later use;

[0049] 4) placing the glass fiber paper obtained in step 2) into a suction filtration funnel; taking out 200 ml of the mixed solution obtained in step 3) and pouring it into a 500 ml suction filtration funnel, filtering it to evenly distribute the absorbent powder inside the glass fiber paper, thereby obtaining an absorbent composite glass fiber paper;

[0050] 5) The absorbent composite glass fiber paper obtained in step 4) was mixed with 20g / m 2 The high-strength absorbing paper is obtained by compounding the PET non-woven fabric and impregnating it with a water-soluble resin adhesive, and then drying it at 150° C. for 30 minutes.

[0051] Take a picture of the high-strength absorbing paper mentioned above. Figure 2 As shown. Figure 2 It can be seen that glass fibers of different thicknesses create pores of different sizes. From top to bottom, the pores are distributed in a gradient from large to small. It is precisely this glass fiber paper with different pore sizes that intercepts the absorber powder inside. As the pore size distribution of the glass fiber paper increases, the absorber powder presents a gradient distribution of interception content from top to bottom.

[0052] Example 2

[0053] This embodiment provides a method for preparing high-strength absorbing paper, comprising the following steps:

[0054] 1) Mix 3 g of 3 μm-diameter alkali-free glass fiber and 1 g of 1 μm-diameter alkali-free glass fiber with 8 L of water and disperse them evenly to obtain a slurry;

[0055] 2) forming the slurry obtained in step 1) on a sheet-making machine to obtain formed glass fiber paper; pressing the obtained formed glass fiber paper at 20N, and then drying it in a drying oven at 100°C for 2 minutes to obtain glass fiber paper;

[0056] 3) Mix 0.05 g of MXene (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) with 2.1 L of water and stir to obtain a mixed solution for later use;

[0057] 4) placing the glass fiber paper obtained in step 2) into a suction filtration funnel; taking out 200 ml of the mixed solution obtained in step 3) and pouring it into a 500 ml suction filtration funnel, filtering it to distribute the absorbent powder inside the glass fiber paper, thereby obtaining an absorbent composite glass fiber paper;

[0058] 5) The absorbent composite glass fiber paper obtained in step 4) was mixed with 20g / m 2 The high-strength absorbing paper is obtained by compounding the PET non-woven fabric and impregnating it with a water-soluble resin adhesive, and then drying it at 150° C. for 30 minutes.

[0059] Example 3

[0060] This embodiment provides a method for preparing high-strength absorbing paper, comprising the following steps:

[0061] 1) 2 g of 5 μm-diameter alkali-free glass fiber was mixed with 4 L of water and dispersed evenly to obtain a first slurry, and then the first slurry was formed on a sheet-making machine to obtain a first formed glass fiber paper;

[0062] 2) 2 g of alkali-free glass fiber with a fiber diameter of 2 μm was mixed with 4 L of water and dispersed evenly to obtain a second slurry, and then the obtained second slurry was formed on a sheet paper machine to obtain a second formed glass fiber paper;

[0063] 3) Compounding the first shaped glass fiber paper obtained in step 1) with the second shaped glass fiber paper obtained in step 2), pressing the composite at 20 N, and then drying the composite in a drying oven at 100° C. for 2 minutes to obtain a double-layer gradient shaped glass fiber paper;

[0064] 4) Mix 0.1 g of MXene (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) with 1.1 L of water and stir to obtain a mixed solution for later use;

[0065] 5) placing the double-layer gradient-formed glass fiber paper obtained in step 3) into a suction filtration funnel; taking out 200 mL of the mixed solution obtained in step 4) and pouring it into a 500 mL suction filtration funnel, and filtering it to distribute the absorbent powder inside the double-layer gradient-formed glass fiber paper, thereby obtaining an absorbent composite glass fiber paper;

[0066] 6) The absorbent composite glass fiber paper obtained in step 5) was mixed with 20g / m 2 The PET non-woven fabric is composited and impregnated with a water-soluble resin adhesive, and then dried at 150° C. for 30 minutes to obtain the high-strength absorbing paper. Figure 3 .Depend on Figure 3From the cross-sectional microscopic morphology of the layered gradient glass fiber paper, we can see that the upper glass fiber builds a sparse structure with a larger pore size, while the lower glass fiber builds a dense structure with a smaller pore size. The overall pore size changes from top to bottom. In this way, after intercepting the absorber, the absorber presents a gradient distribution inside the glass fiber paper, which is conducive to the entry and loss of electromagnetic waves.

[0067] Example 4

[0068] This embodiment differs from Example 1 in that, in step 4), 0.3 g of graphite powder (particle size 0.5 μm) and 0.8 g of cobalt trioxide powder (particle size 0.3 μm) were mixed and stirred with 1.1 L of water to prepare a mixed solution. The remaining steps and parameters were the same as in Example 1.

[0069] Example 5

[0070] This embodiment differs from Example 1 in that, in step 4), 1 g of graphite powder (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) are mixed and stirred with 2.2 L of water to form a mixed solution. The remaining steps and parameters are the same as in Example 1.

[0071] Example 6

[0072] This example differs from Example 5 in that, in step 4), 0.05 g of MXene (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) were mixed with 2.1 L of water and stirred to form a mixed solution, which was then set aside. The remaining steps and parameters were the same as in Example 5.

[0073] Example 7

[0074] The difference between this embodiment and embodiment 3 is that in step 5), 0.1 g of graphite powder (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) are mixed with 1.1 L of water and stirred to prepare a mixed solution for later use. The remaining steps and parameters are the same as those in embodiment 3.

[0075] Example 8

[0076] The difference between this embodiment and embodiment 3 is that in step 5), 0.1 g of graphite powder (particle size 0.5 μm) and 1 g of cobalt trioxide powder (particle size 0.3 μm) are mixed with 2.2 L of water and stirred to prepare a mixed solution for later use. The remaining steps and parameters are the same as those in embodiment 3.

[0077] Example 9

[0078] The difference between this embodiment and embodiment 1 is that in step 1) of this embodiment, 3 g of alumina fibers with a diameter of 2 μm are mixed with 6 L of water and dispersed evenly to obtain a slurry. The remaining steps and parameters are the same as those of embodiment 1.

[0079] Comparative Example 1

[0080] 1) Mix 5 g of 32 μm alkali-free glass fiber with 8 L of water and disperse evenly to obtain a slurry;

[0081] 2) forming the slurry obtained in step 1) on a sheet-making machine, pressing the obtained formed paper at 20N, and then drying it in a drying oven at 100°C for 2 minutes to obtain glass fiber paper;

[0082] 3) Mix 0.05 g of MXene (particle size 0.5 μm), 1 g of cobalt trioxide powder (particle size 0.3 μm) with 2.1 L of water and stir to obtain a mixed solution for later use;

[0083] 4) The glass fiber paper obtained in step 2) was placed in a suction filtration funnel; 200 ml of the mixed solution obtained in step 3) was taken out and poured into a 500 ml suction filtration funnel and filtered to distribute the absorber powder inside the glass fiber paper, thereby obtaining an absorber composite glass fiber paper. It can be clearly seen that the obtained absorber composite glass fiber paper cannot intercept MXene, resulting in the absorber and glass fiber paper being unable to form a composite material.

[0084] The high-strength absorbing papers prepared in Examples 1-9 were tested for thickness, burst resistance, and average return loss. The test results are shown in Table 1. The thickness was tested according to GB / T451; the burst resistance was tested according to GB / T454; and the average return loss was measured using a vector network analyzer.

[0085] Table 1. Summary of properties of high-strength absorbing paper of Examples 1-9

[0086]

[0087] From the data in Table 1, it can be seen that the high-strength absorbing paper of Examples 1-9 of the present invention has a thickness of 0.50 mm to 0.63 mm, a burst strength of 347 kPa to 383 kPa, and an average reflection loss value of -23 dB to -11 dB between 2 and 18 GHz.

[0088] Comparing Example 1 with Example 4, it can be seen that changing the ratio of the absorber will affect the average reflection loss between 2 and 18 GHz. This is because the ratio of the absorber controls the impedance matching. The better the impedance matching, the easier it is for electromagnetic waves to enter the interior of the glass fiber paper and be lost.

[0089] Comparing Example 1 with Example 5, it can be seen that reducing the concentration of the absorber mixture slightly reduces the absorbing performance. This is because the concentration of the absorber decreases, and the amount of absorber intercepted when passing through the interior of the glass fiber paper decreases.

[0090] Comparing Example 6 with Example 5 and Example 3 with Example 7, it can be seen that changing the type of absorber will change the average reflection loss between 2 and 18 GHz. This is because different absorbers have different dielectric and magnetic properties, resulting in different electrical and magnetic losses and thus different absorbing performance.

[0091] Comparing Example 5 with Example 8, it can be seen that when glass fiber papers with different structures intercept the same absorbent mixture, the performance of the double-layer absorbing paper is better than that of the single-layer absorbing paper.

[0092] Comparing Example 9 with Example 1, it can be seen that the fiber type can affect the comprehensive performance of the absorbing paper.

[0093] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] The numerical ranges described in the present invention include all values ​​within the range, and include range values ​​formed by any two values ​​within the range. Different numerical values ​​of the same indicator appearing in all embodiments of the present invention can be arbitrarily combined to form a range value.

[0095] The technical features in the claims and / or the specification of the present invention may be combined, and the manner of combination is not limited to the combination obtained by reference in the claims. The technical solutions obtained by combining the technical features in the claims and / or the specification are also within the scope of protection of the present invention.

[0096] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiment based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing high-strength absorbing paper, characterized in that: The following steps are involved: S1: uniformly dispersing glass fibers and water to obtain a slurry; the fibers are selected from glass fibers of different diameters, and the diameter of the fibers is ≤20 μm; S2: forming the slurry obtained in step S1 into glass fiber paper to obtain formed glass fiber paper; S3: mixing the absorbent powder with water and stirring evenly to obtain a mixed solution; the mass ratio of the glass fiber to the absorbent is 3:1.1 to 200:1; S4: pouring the mixed solution obtained in step S3 onto the formed glass fiber paper obtained in step 2) and filtering the mixed solution to distribute the absorbent powder inside the glass fiber paper to obtain the absorbent composite glass fiber paper; S5: The absorbent composite glass fiber paper obtained in step S4 is sizing and compounded with a PET non-woven fabric, and then dried to obtain the high-strength absorbing paper.

2. The method for preparing high-strength absorbing paper according to claim 1, wherein: In step S1, the mass ratio of the glass fiber to water is (1-80):10000; the fibers are selected from glass fibers of different wire diameters, and the wire diameter is ≤20 μm.

3. The method for preparing high-strength absorbing paper according to claim 1, wherein: In step S2, after the glass fiber paper forming step, the step of drying the formed glass fiber paper is also included, and the drying temperature is 80-120°C.

4. The method for preparing high-strength absorbing paper according to claim 1, wherein: In step S2, after the glass fiber paper forming step, the method further comprises the steps of compounding, pressing and drying at least two formed glass fiber papers; the pressing load is 5-80N; and the drying temperature is 80-120°C.

5. The method for preparing high-strength absorbing paper according to claim 1, wherein: In step S3, the absorber powder is a conductive or magnetic powder or fiber, which is selected from at least one of graphite powder, graphene, MoS2, MXene, ferrite, iron powder, cobalt powder and nickel powder; the concentration of the absorber in the mixed solution is 0.001-30 g / L.

6. The method for preparing high-strength absorbing paper according to claim 5, wherein: In step S3, the absorber powder is selected from at least one of graphite powder, graphene, MoS2, MXene, ferrite, iron powder, cobalt powder and nickel powder.

7. The method for preparing high-strength absorbing paper according to claim 1, wherein: In step S5, the glue used in the sizing is a thermosetting or thermoplastic polymer with a temperature resistance higher than 150°C; the non-woven fabric is 15-40g / m 2 PET non-woven fabric; the sizing method includes one of spraying, soaking and filtration; the sizing amount is 2wt%-15wt%.

8. A high-strength absorbing paper, characterized in that: The high-strength absorbing paper is a single-layer or multi-layer gradient with a thickness of 0.20 mm to 0.70 mm, a bursting strength greater than or equal to 300 kPa, and an average reflection loss value between 2-18 GHz less than -10 dB; the high-strength absorbing paper is prepared by the method according to any one of claims 1 to 7.

9. An isolating stealth material, characterized in that: The isolation stealth material is the high-strength absorbing paper described in claim 8.

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