Sound insulation structure and preparation method thereof

Abstract

The invention relates to a sound insulation structure and a preparation method thereof, and the sound insulation structure comprises a sound absorption layer and at least one sound insulation layer; the sound insulation layer is coated on at least one surface of the sound absorption layer; the sound absorption layer comprises a void material frame and acoustic nano-particles and aerogel distributed in the void material frame, the distribution density of the acoustic nano-particles gradually decreases in the direction perpendicular to the sound insulation layer, and the aerogel is uniformly dispersed; the acoustic nanoparticles are selected from iron oxide and / or zinc oxide. The sound insulation structure has the beneficial effects that the prepared sound insulation structure has an excellent sound insulation effect, the sound insulation performance of the sound insulation structure is improved by more than one time compared with that of a common material, and the sound insulation structure can be widely applied to sound insulation scenes of building areas or other fields with high sound insulation requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and in particular to a sound insulation structure and a preparation method thereof. Background Art

[0002] Sound insulation refers to materials used to reduce the transmission of sound or absorb sound energy. Sound insulation is an important consideration in fields such as architecture, engineering design, and vehicle manufacturing to control noise pollution and improve environmental comfort.

[0003] At present, the sound insulation materials on the market are generally made of fiber materials and sound insulation structures. The sound insulation materials are generally made of concrete, gypsum board and other materials. The composite production process is complicated, and the materials are thick and heavy. At the same time, the sound insulation effect of the materials is average, which is difficult to meet the application scenarios with high sound insulation requirements and restrictions on material thickness. Therefore, the sound insulation effect of existing sound insulation materials needs to be improved, and their production, transportation and use costs are high. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a sound insulation structure and a preparation method thereof, which solves the technical problems that the sound insulation effect of the existing sound insulation materials needs to be improved, the material manufacturing process is complicated and the cost is high.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides a sound insulation structure, comprising a sound absorbing layer and at least one sound insulation layer; the sound insulation layer is coated on at least one surface of the sound absorbing layer; the sound absorbing layer comprises a void material frame and acoustic nanoparticles and aerogel distributed therein, and the distribution density of the acoustic nanoparticles decreases along a direction perpendicular to the sound insulation layer, and the aerogel is uniformly dispersed; the acoustic nanoparticles are iron oxide and / or zinc oxide.

[0009] Among them, the average hardness and average density of the sound insulation layer are greater than those of the sound absorption layer, so as to play a sound insulation role, and at the same time can support the overall material and ensure the overall strength of the sound insulation structure.

[0010] As a preferred embodiment of the present invention, in the sound insulation structure, when there is one sound insulation layer, the sound insulation layer is arranged on the surface of the sound absorbing layer on the side with a higher density of acoustic nanoparticles; when there are two or more sound insulation layers, at least one sound insulation layer is arranged on the surface of the sound absorbing layer on the side with a higher density of acoustic nanoparticles.

[0011] As a preferred embodiment of the present invention, in the sound insulation structure, the void material frame is a shaped layered fiber material; the volume percentage of aerogel and layered fiber material is 20-50%; the mass percentage of acoustic nanoparticles and layered fiber material is 1.25-2.5‰; and the thickness of the sound absorbing layer is 10-25mm.

[0012] The volume of the layered fiber material is calculated according to its dimensions (length, width, height) after being shaped in a mold.

[0013] As a preferred embodiment of the present invention, in the sound insulation structure, the fiber material is selected from one or a combination of two or more of ceramic fiber, glass fiber and polypropylene fiber; the aerogel is selected from one or a combination of two or more of silica aerogel, polyurethane aerogel and polystyrene aerogel.

[0014] As a preferred embodiment of the present invention, in the sound insulation structure, the sound insulation layer comprises cured waterborne polyurethane and acoustic nanoparticles uniformly dispersed therein; wherein the mass ratio of the waterborne polyurethane to the acoustic nanoparticles is 6-10:1; and the thickness of the sound insulation layer is 1-2 mm.

[0015] As a preferred embodiment of the present invention, in the sound insulation structure, the particle size of the acoustic nanoparticles is 20-100 μm, and the particle size of the acoustic nanoparticles is the same. Acoustic nanoparticles with the same particle size can establish a better density gradient during the distribution process.

[0016] In a second aspect, an embodiment of the present invention provides a method for preparing the sound insulation structure according to the first aspect, comprising the following steps:

[0017] S1. Dispersing the fibers uniformly in water to obtain fiber slurry, placing the fiber slurry into a mold, draining it, and then drying it into a fiber blanket;

[0018] S2, evenly mix the solvent and the aerogel raw material, then add the cross-linking agent and stir evenly, adjust the pH to neutral, add the acoustic nanoparticles, disperse evenly, and prepare an impregnation solution; wherein the pH adjusting reagent is a weak acid or a weak base, such as acetic acid solution, carbonic acid solution, citric acid solution, etc., and the weak base reagent is ammonia water, sodium bicarbonate solution, sodium carbonate solution, etc. In the cross-linking of aerogels, the use of weak acids or weak bases can provide a milder and more controllable reaction environment, which helps to form a more uniform and stable network structure, which can improve the mechanical properties of the final product.

[0019] The fiber blanket is kept in a horizontal state, and the fiber blanket is evenly impregnated with the impregnation solution from top to bottom. The impregnation solution inside the impregnated fiber blanket is aged and dried to obtain a sound absorbing layer;

[0020] S3, preparing a sound insulation layer coating liquid, pouring the coating liquid evenly on the upper surface of the sound absorption layer, scraping the liquid surface, curing and drying, to obtain the sound insulation structure.

[0021] As a preferred embodiment of the present invention, in the method for preparing the sound insulation structure, in S1,

[0022] Before the fibers are evenly dispersed in water, a dispersant is added to the water at a mass of 5-10‰ of the fiber dry weight;

[0023] The drained fibers are dried at 100-150°C.

[0024] As a preferred embodiment of the present invention, in the method for preparing the sound insulation structure, in S2,

[0025] The volume ratio of solvent to aerogel raw material is 1-5:1;

[0026] The cross-linking agent is a silicate or a phosphate, and the mass of the cross-linking agent is equal to that of the aerogel raw material;

[0027] After adding the acoustic nanoparticles, the dispersion process is as follows: stirring at 60-70 r / min for 15-20 min, and then ultrasonic dispersion for 20-25 min;

[0028] The impregnated solution inside the fiber blanket is aged at 40-80° C. for 6-8 hours.

[0029] As a preferred embodiment of the present invention, in the method for preparing the sound insulation structure, in S3,

[0030] The sound insulation layer coating liquid is prepared by uniformly mixing waterborne polyurethane and acoustic nanoparticles, and then adding a curing agent and a defoaming agent, and mixing to obtain a coating liquid;

[0031] The curing agent is sodium polyacrylate, which accounts for 5-10% of the mass of the aerogel raw material;

[0032] The defoaming agent is liquid lithium silicate, which accounts for 1-2% of the volume of the aerogel raw material;

[0033] The curing and drying steps are as follows: curing at room temperature for 10-20 hours, and then drying at 100-150°C for 5-6 hours.

[0034] (III) Beneficial effects

[0035] The beneficial effects of the present invention are as follows: a sound insulation structure and a preparation method thereof of the present invention, because the acoustic nanoparticles with a decreasing density from the outside to the inside are distributed in the void material frame of the sound absorbing layer, a gradient absorption effect is formed on the noise; the void material frame is evenly dispersed with aerogel, and the porosity of the aerogel can be as high as 99.8%. The low density enables the aerogel to absorb more sound energy without reflecting too much sound, and cooperates with the gradient distributed acoustic nanoparticles to effectively absorb the sound of a wider frequency band, and the sound absorption effect is excellent. At the same time, the aerogel can achieve the effect of lightweight sound insulation. A sound insulation layer is arranged on one side of the sound absorbing layer, and the sound absorbing layer is attached to the sound insulation layer, and the sound insulation and sound absorption effects are played at the same time. Compared with the prior art, the sound insulation structure prepared by the present invention has excellent sound insulation effect, and its sound insulation performance is improved by more than 1 times compared with ordinary porous materials, and can be widely used in sound insulation scenes in building areas or other fields with high sound insulation requirements; the sound absorbing layer is a porous material, which has the characteristics of lightness and thinness while enhancing the sound absorption effect, and the application scene is flexible and has great development potential. In addition, the preparation process of the sound insulation structure is simple, which is conducive to mass production and saves production costs.

[0036] When there is only one sound insulation layer, the sound insulation layer is arranged on the surface of the side of the sound absorbing layer with a larger density of acoustic nanoparticles, which has a better sound insulation effect than that arranged on the side with a smaller density of acoustic nanoparticles.

[0037] The void material framework of the sound absorbing layer is a shaped layered fiber material, which is conducive to the adsorption of acoustic nanoparticles thereon and forms a gradient distribution density.

[0038] The mass volume percentage of aerogel and layered fiber material is 1-2%, the mass volume percentage of acoustic nanoparticles and layered fiber material is 1.25-2.5‰, and the thickness of the sound absorbing layer is 10-25mm. This can save raw materials to the greatest extent, ensure sound insulation effect, and the sound insulation structure is light and thin.

[0039] The sound insulation layer includes cured waterborne polyurethane and acoustic nanoparticles uniformly dispersed therein, the mass ratio of waterborne polyurethane to acoustic nanoparticles is 6-10:1, the thickness of the sound insulation layer is 1-2 mm, and the cured waterborne polyurethane forms a dense sound insulation layer, which overcomes the disadvantage of soft fibers of the sound absorbing layer. At the same time, the acoustic nanoparticles mixed therein play a sound absorbing role together with the acoustic nanoparticles in the sound absorbing layer, thereby enhancing the overall sound absorption effect.

[0040] The sum of the thickness of the sound-absorbing layer and the sound-insulating layer can be as low as 11-12 mm, which is light and thin and suitable for application scenarios where the thickness of sound insulation materials is restricted.

[0041] The acoustic nanoparticles are iron oxide and / or zinc oxide, the particle size of the acoustic nanoparticles is 20-100 μm, and the particle size of the acoustic nanoparticles is consistent. The sound insulation structure finally prepared has the best sound insulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is an overall schematic diagram of the sound insulation structure prepared in Example 1 of the present invention;

[0043] Figure 2 for Figure 1 Schematic diagram of the interior of the sound-absorbing layer of the middle sound insulation structure;

[0044] Figure 3 This is a schematic diagram of the interior of the sound absorbing layer of the sound insulation structure prepared in Comparative Example 1 of the present invention;

[0045] Figure 4 A line graph showing the sound insulation effect test of the sound insulation structures prepared in Examples 1, 2 and 3 of the present invention;

[0046] Figure 5 A line graph showing the sound insulation effect test of the sound insulation structures prepared in Examples 2 and 4 of the present invention;

[0047] Figure 6 It is a line graph of the sound insulation effect test of the sound insulation structure prepared in Example 2 of the present invention and Comparative Example 1.

[0048] [Description of Reference Numerals]

[0049] 1: sound absorbing layer; 11: fiber; 12: acoustic nanoparticles; 13: aerogel; 2: sound insulating layer. DETAILED DESCRIPTION

[0050] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0051] A sound insulation structure and a preparation method thereof proposed in an embodiment of the present invention solve the technical problems that the sound insulation effect of existing sound insulation materials needs to be improved, and the material manufacturing process is complicated and costly; wherein, the sound insulation structure forms a gradient absorption effect on noise due to the acoustic nanoparticles with a decreasing density from the outside to the inside distributed in the void material frame of the sound absorbing layer; the void material frame is evenly dispersed with aerogel, and the porosity of the aerogel can be as high as 99.8%. The low density enables the aerogel to absorb more sound energy without reflecting too much sound, and cooperates with the gradient distributed acoustic nanoparticles to effectively absorb sound in a wider frequency band, and the sound absorption effect is excellent. At the same time, the aerogel can achieve the effect of lightweight sound insulation. A sound insulation layer is set on one side of the sound absorbing layer, and the sound absorbing layer is attached to the sound insulation layer, and the sound insulation and sound absorption functions are played at the same time. Compared with the prior art, the sound insulation structure prepared by the present invention has excellent sound insulation effect, and its sound insulation performance is more than 1 times that of ordinary materials, and can be widely used in sound insulation scenes in building areas or other fields with high sound insulation requirements; the sound absorption layer is a void material, which enhances the sound absorption effect and has the characteristics of being light and thin, with flexible application scenarios and huge development potential. In addition, the preparation process of the sound insulation structure is simple, which is conducive to mass production and saves production costs.

[0052] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0053] Example 1

[0054] This embodiment provides a method for preparing a sound insulation structure. Figure 1 and Figure 2 , specifically including the following steps:

[0055] (1) Fiber forming: ceramic fiber 11, water, and cellulose are fed into a mixer and stirred at 1000 r / min for 15 min to prepare a fiber slurry for use, wherein the amount of water is sufficient to completely immerse the ceramic fiber, and the amount of cellulose accounts for 5‰ of the fiber dry weight;

[0056] (2) Pour the fiber slurry into a square mold that can filter water, and after all the water is filtered out, move the wet-formed fibers horizontally to an oven and dry them at 80°C to form a fiber blanket;

[0057] (3) preparing an impregnation solution: mixing water and a silica aerogel precursor (aerogel raw material) solution at a volume ratio (water-to-gel ratio) of 4:1, adding lithium silicate (cross-linking agent) in an amount equal to the amount of the silica aerogel precursor solution, stirring evenly, adding a small amount of acid to adjust the pH to neutral, adding iron oxide acoustic nanoparticles 12 with a particle size of 100 μm, and the mass volume percentage of iron oxide in the dimensional material is 1.25‰, stirring at 60 r / min, stirring for 15 min, and ultrasonically dispersing for 20 min to prepare an impregnation solution;

[0058] (4) Place a layer of guide net on the top and bottom of the fiber blanket, and then place a layer of perforated steel plate on the top and bottom for support, fix it with a clamp, pour the impregnation solution prepared in (3) from the top until the fiber blanket is fully soaked, take it out and put it in an oven, age the impregnation solution inside the fiber blanket at 80°C for 6h (i.e., the gel temperature is 80°C), and then dry it to obtain a sound absorbing layer 1 with a thickness of 10mm and distributed with silica aerogel 13; wherein the total volume of the impregnation solution is the same as the total volume of the fiber blanket to ensure complete soaking;

[0059] (5) preparing an acoustic coating liquid: placing waterborne polyurethane and iron oxide acoustic nanoparticles with a particle size of 100 μm in a magnetic stirrer at a mass ratio of 10:1 and stirring for 5 min, then adding a sodium polyacrylate curing agent, wherein the mass ratio of the curing agent to the waterborne polyurethane is 0.05%; then adding a defoaming agent accounting for 1% of the volume of the waterborne polyurethane, stirring evenly, and preparing an acoustic coating liquid;

[0060] (6) Take out the fiberboard prepared in (4), pour the acoustic coating liquid in (5) evenly on the upper surface, scrape the surface liquid with a scraper, and place it at room temperature for curing for 10-20 hours to form a 2 mm thick sound insulation layer 2 on the upper surface of the sound absorption layer, and then put it into an oven and dry it at 80°C for 5 hours to finally obtain a sound insulation structure.

[0061] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0062] Example 2

[0063] This embodiment provides a method for preparing a sound insulation structure. The difference between this embodiment and embodiment 1 is that in step (4), the impregnation solution inside the fiber blanket after impregnation is aged at 60° C. for 8 h; the remaining steps are the same.

[0064] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0065] Example 3

[0066] This embodiment provides a method for preparing a sound insulation structure. The difference between this embodiment and embodiment 1 is that in step (4), the impregnation solution inside the fiber blanket after impregnation is aged at 40° C. for 8 h; the remaining steps are the same.

[0067] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0068] Example 4

[0069] This embodiment provides a method for preparing a sound insulation structure. The difference between this embodiment and Embodiment 2 is that the water-to-binder ratio in step (3) is 6:1; and the remaining steps are the same.

[0070] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0071] Comparative Example 1

[0072] This comparative example provides a method for preparing a sound insulation structure. The difference between this comparative example and Example 2 is that in step (1), the iron oxide acoustic nanoparticles with a particle size of 100 μm in step (3) are added in advance when preparing the fiber slurry, so that the nanoparticles are evenly distributed in the fiber blanket. Figure 3 ;

[0073] Correspondingly, the step of adding nanoparticles in step (3) is omitted; the remaining steps are the same.

[0074] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0075] Comparative Example 2

[0076] This comparative example provides a method for preparing a sound insulation structure. The difference between this comparative example and Example 2 is that the iron oxide acoustic nanoparticles with a particle size of 100 μm in step (3) are replaced by a mixture of iron oxide acoustic nanoparticles with a particle size of 100 μm and iron oxide acoustic nanoparticles with a particle size of 50 μm, each accounting for half; the remaining steps are the same.

[0077] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0078] Comparative Example 3

[0079] This comparative example provides a method for preparing a sound insulation structure. The difference between this comparative example and Example 2 is that the iron oxide acoustic nanoparticles with a particle size of 100 μm in step (3) are replaced by a mixture of iron oxide acoustic nanoparticles with particle sizes of 100 μm, 50 μm, and 20 μm, each accounting for 1 / 3 of the amount; the remaining steps are the same.

[0080] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0081] Comparative Example 4

[0082] This comparative example provides a method for preparing a sound insulation structure. The difference between this comparative example and Example 2 is that in step (3), iron oxide acoustic nanoparticles with a particle size of 100 μm are not placed, but are replaced with an equal mass of silica aerogel precursor solution; the remaining steps are the same.

[0083] The sound insulation effect of the prepared sound insulation structure was tested by the transfer function method, as shown in Table 1.

[0084] Table 1 Sound insulation test results

[0085] Example Average sound insulation / dB Maximum sound isolation / dB Comparative Example Average sound insulation / dB Example 1 38.23 49.68 Comparative Example 1 18.72 Example 2 24.39 32.94 Comparative Example 2 20.19 Example 3 22.37 36.26 Comparative Example 3 19.69 Example 4 21.79 30.99 Comparative Example 4 18.64

[0086] Based on the above embodiments, comparative examples and test results, the analysis is as follows:

[0087] Example 1 is the best example. The sound insulation structure prepared by it is 38.23dB and the maximum sound insulation volume is 49.68dB. It is also light and thin, has good sound insulation effect, and is easy to transport and install.

[0088] Comparing Example 2 and Example 3 with Example 1, it can be seen that the best aging temperature for the aerogel impregnation solution in step (4) is 80°C. As the aging temperature decreases, the sound insulation effect of the prepared sound insulation structure decreases.

[0089] Comparing Example 4 with Example 1, it can be seen that the water-cement ratio in step (3) is 4:1, and the sound insulation effect of the prepared sound insulation structure is the best. Increasing the water-cement ratio (i.e. increasing the amount of water used) will reduce the sound insulation effect of the sound insulation structure; on the contrary, reducing the water-cement ratio (i.e. reducing the amount of water used) will improve the sound insulation effect of the sound insulation structure, but with the increase in the weight and cost of the sound insulation structure, considering the weight and cost, the water-cement ratio is 4:1, which is more cost-effective. Of course, if there is a higher sound insulation demand, it can be considered to reduce the amount of water or increase the amount of gel raw material on the basis of a water-cement ratio of 4:1. Similarly, if the sound insulation demand is relatively low, it can be considered to increase the amount of water or reduce the amount of gel raw material on the basis of a water-cement ratio of 4:1 to reduce costs.

[0090] Comparison of Example 2 with Comparative Example 1 shows that the sound insulation structure of acoustic nanoparticles with decreasing density in the sound absorbing layer has better sound insulation effect than the sound insulation structure of acoustic nanoparticles with uniform distribution in the sound absorbing layer.

[0091] Comparison of Example 2 with Comparative Examples 2 and 3 shows that when the particle size of the acoustic nanoparticles in the sound absorbing layer is one, the sound insulation effect is better than when two or more particle sizes of acoustic nanoparticles are mixed, that is, when the particle size of the acoustic nanoparticles is one and the particle size is larger (100 μm).

[0092] Comparison between Comparative Examples 2, 3 and 4 shows that without the effect of acoustic nanoparticles, the sound insulation effect is further weakened.

[0093] It should be noted that, compared with setting the sound insulation layer on one side of the sound absorption layer under the same conditions, setting the sound insulation layer on both sides of the sound absorption layer can improve the sound insulation effect to a certain extent, but the corresponding production cost is increased and the process flow is relatively complicated. Increasing the thickness of the sound insulation layer can also effectively improve the sound insulation effect.

[0094] When there is only one sound insulation layer, the sound insulation layer is arranged on the surface of the side of the sound absorbing layer where the density of acoustic nanoparticles is larger, and the density of acoustic nanoparticles distributed in the sound insulation layer is higher than the density of acoustic nanoparticles in the adjacent sound absorbing layer, so that the acoustic nanoparticles in the sound insulation layer and the acoustic nanoparticles in the sound absorbing layer form a continuous density gradient, and the sound insulation effect is better.

[0095] In step (4) of the embodiment, a layer of guide net is placed on the top and bottom of the fiber blanket, and then a layer of perforated steel plate is placed on the top and bottom for support to prevent the fiber blanket from deformation. The impregnation solution prepared in step (3) is poured from above. When the impregnation solution impregnates the fiber blanket from top to bottom, the acoustic nanoparticles are insoluble in the aerogel raw material. The method of pouring the solution from above allows the acoustic nanoparticles to gradually gather on the fibers, and in this process, the aerogel solution can evenly infiltrate the fiber blanket. This preparation method can form a density gradient distribution of the acoustic nanoparticles along the thickness direction of the fiber blanket.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sound insulation structure, characterized in that: comprising a sound absorbing layer and at least one sound insulating layer; The sound insulation layer is coated on at least one surface of the sound absorption layer; The sound absorbing layer includes a void material frame and acoustic nanoparticles and aerogels distributed therein, wherein the distribution density of the acoustic nanoparticles decreases along a direction perpendicular to the sound insulation layer, and the aerogels are evenly dispersed; The acoustic nanoparticles are iron oxide and / or zinc oxide.

2. The sound insulation structure according to claim 1, characterized in that: When there is one sound insulation layer, the sound insulation layer is arranged on the surface of the side of the sound absorbing layer where the density of acoustic nanoparticles is greater; When there are two or more sound insulation layers, at least one sound insulation layer is disposed on the surface of the sound absorbing layer on the side where the acoustic nanoparticles distribution density is higher.

3. The sound insulation structure according to claim 1, characterized in that: The void material frame is a fiber material that is shaped into a layer; The volume percentage of aerogel and layered fiber material is 20-50%; The mass percentage of acoustic nanoparticles to layered fiber material is 1.25-2.5‰; The thickness of the sound absorbing layer is 10-25mm.

4. The sound insulation structure according to claim 3, characterized in that: The fiber material is selected from one or a combination of two or more of ceramic fiber, glass fiber and polypropylene fiber; The aerogel is selected from one or a combination of two or more of silica aerogel, polyurethane aerogel and polystyrene aerogel.

5. The sound insulation structure according to claim 1, characterized in that: The sound insulation layer comprises cured waterborne polyurethane and acoustic nanoparticles uniformly dispersed therein; Wherein, the mass ratio of waterborne polyurethane to acoustic nanoparticles is 6-10:1; The thickness of the sound insulation layer is 1-2mm.

6. The sound insulation structure according to claim 1 or 5, characterized in that: The particle size of the acoustic nanoparticles is 20-100 μm, and the particle sizes of the acoustic nanoparticles are the same.

7. A method for preparing the sound insulation structure according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Dispersing the fibers uniformly in water to obtain fiber slurry, placing the fiber slurry into a mold, draining it, and then drying it into a fiber blanket; S2, evenly mix the solvent and the aerogel raw material, then add the cross-linking agent and stir evenly, adjust the pH to neutral, add the acoustic nanoparticles, disperse evenly, and prepare an impregnation solution; The fiber blanket is kept in a horizontal state, and the fiber blanket is evenly impregnated with the impregnation solution from top to bottom. The impregnation solution inside the impregnated fiber blanket is aged and dried to obtain a sound absorbing layer; S3, preparing a sound insulation layer coating liquid, pouring the coating liquid evenly on the upper surface of the sound absorption layer, scraping the liquid surface, curing and drying, to obtain the sound insulation structure.

8. The method for preparing a sound insulation structure according to claim 7, characterized in that: In S1, Before the fibers are evenly dispersed in water, a dispersant is added to the water at a mass of 5-10‰ of the fiber dry weight; The drained fibers are dried at 100-150°C.

9. The method for preparing a sound insulation structure according to claim 7, characterized in that: In S2, The volume ratio of solvent to aerogel raw material is 1-5:1; The cross-linking agent is a silicate or a phosphate, and the mass of the cross-linking agent is equal to that of the aerogel raw material; After adding the acoustic nanoparticles, the dispersion process is as follows: stirring at 60-70 r / min for 15-20 min, and then ultrasonic dispersion for 20-25 min; The impregnated solution inside the fiber blanket is aged at 40-80° C. for 6-8 hours.

10. The method for preparing a sound insulation structure according to claim 7, characterized in that: In S3, The sound insulation layer coating liquid is prepared by uniformly mixing waterborne polyurethane and acoustic nanoparticles, and then adding a curing agent and a defoaming agent, and mixing to obtain a coating liquid; The curing agent is sodium polyacrylate, which accounts for 5-10% of the mass of the aerogel raw material; The defoaming agent is liquid lithium silicate, which accounts for 1-2% of the volume of the aerogel raw material; The curing and drying steps are as follows: curing at room temperature for 10-20 hours, and then drying at 100-150° C. for 5-6 hours.

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