Sound-absorbing block material, preparation method thereof, and sound-generating device

Abstract

The present invention relates to a sound-absorbing block material and a preparation method and a sound-generating device thereof, wherein the sound-absorbing block material comprises at least two sound-absorbing layers and at least three breathable layers, wherein the breathable layers and the sound-absorbing layers are alternately stacked in sequence to form a multilayer structure, wherein the outermost layer of the sound-absorbing block material is the breathable layer, and the adjacent sound-absorbing layers and the breathable layers are bonded and fixed by a bonding or hot-melt process; wherein the sound-absorbing layer is made by mixing a sound-absorbing material powder, an adhesive and a thickener in a mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively; and the breathable layer is made of a porous breathable material. Compared with the related art, the sound-absorbing block material of the present invention effectively solves the problem that the block material is closed inside and does not exchange gas with air, avoids the risk of possible breakage of the sound-absorbing block material, and effectively improves the service life and sound absorption performance of the sound-absorbing block material.

Description

Technical Field

[0001] The present invention relates to the technical field of sound-generating devices, and in particular to a sound-absorbing block material, a preparation method thereof, and a sound-generating device. Background Art

[0002] In the field of acoustics, in order to improve the audio quality on various mobile terminals, a common practice is to fill the back cavity of the sound-emitting device with sound-absorbing materials to reduce the resonance frequency and achieve a physically larger back cavity volume.

[0003] Related technology: The sound-absorbing material commonly used in small cavities is mainly a molecular sieve with a nano-scale microporous structure. The molecular sieve is often formed into particles of a certain size in the process, and then filled in the back cavity of the sound-generating device to play a sound-absorbing role.

[0004] However, the sound-absorbing particles will lose powder and break when they collide with each other. At the same time, static electricity occurs when the particles are filled, making filling difficult. Another related solution is to mold the zeolite into blocks, which does not require a complex granulation process. This type of solution is simple to process and can reduce the risk of breakage caused by collisions between particles. However, the block is large in size, the strength decreases, and as the thickness increases, the air permeability of the block becomes poor. The sound-absorbing powder inside the block cannot play a sound-absorbing role, reducing the overall sound absorption efficiency of the block. When the block is used in the back cavity of the speaker device, the block is in direct contact with the hard inner wall of the cavity, and the block collides and rubs against the inner wall, causing it to break and lose powder easily.

[0005] Therefore, it is necessary to provide a new sound-absorbing block material to solve the above problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a sound-absorbing block material with good sound-absorbing performance and simple application, a preparation method thereof, and a sound-generating device.

[0007] In order to solve the above technical problems, the present invention provides a sound-absorbing block material, the sound-absorbing block material comprises at least two sound-absorbing layers and at least three air-permeable layers, the air-permeable layers and the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, the outermost layer of the sound-absorbing block material is the air-permeable layer, and the adjacent sound-absorbing layers and the air-permeable layers are bonded and fixed by a gluing or hot-melt process; wherein,

[0008] The sound absorbing layer is made by mixing sound absorbing material powder, adhesive and thickener in a mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively;

[0009] The air-permeable layer is made of porous air-permeable material.

[0010] Preferably, the thickness of the air permeable layer is in the range of 0.1-2 mm, and the thickness of the sound absorbing layer is in the range of 0.1-5 mm.

[0011] Preferably, the thickness of the sound absorbing layer is in the range of 0.1-2 mm.

[0012] Preferably, the air-permeable layer is softened by heat through a hot-melt process and then bonded to the sound-absorbing layer, and the hot-melt temperature is 100-200°C.

[0013] Preferably, the air permeable layer is coated with adhesive and then bonded to the sound absorbing layer, and the adhesive is at least one of polyacrylate, epoxy resin, polyurethane and silicone adhesives.

[0014] Preferably, the sound absorbing material powder is a zeolite material, the zeolite material is at least one of MFI, MEL, and FER, and the particle size of the zeolite material is less than 10 μm.

[0015] Preferably, the adhesive is at least one of polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethylvinyl acetate.

[0016] Preferably, the thickener is at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol.

[0017] Preferably, the porous breathable material is at least one of melamine foam, polyurethane foam, EVA foam and EPDM foam having an open-pore structure.

[0018] Preferably, the porous breathable material is made of interwoven fiber filaments having an interconnected structure, and the fiber filaments are at least one of cotton fiber, polyester fiber, polyethylene fiber, and polyacrylonitrile fiber.

[0019] The present invention also provides a method for preparing the sound-absorbing block material as described above, the method comprising the following steps:

[0020] The sound absorbing material powder, adhesive, thickener and water are mixed in a mass ratio of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts respectively to prepare a sound absorbing material slurry;

[0021] The sound absorbing material slurry is prepared into a sound absorbing layer by a low temperature drying process;

[0022] The prepared at least three layers of breathable layers and at least two layers of the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, so that the outermost layer after stacking is the breathable layer, and the adjacent breathable layers and the sound-absorbing layers are bonded and fixed by a gluing or hot-melt process to prepare the sound-absorbing block material.

[0023] The present invention also provides a sound-generating device, comprising a shell having a receiving space, and a sound-generating unit received in the receiving space, wherein the sound-generating unit and the shell are arranged to form a rear cavity, wherein the rear cavity is filled with the sound-absorbing block material as described above.

[0024] Preferably, the air permeable layer of the outermost layer of the sound-absorbing block material is in contact with the inner wall of the rear cavity, and the sound-absorbing block material is squeezed and fixed in the rear cavity through the inner wall of the shell.

[0025] Compared with the related art, the sound-absorbing block material provided by the present invention includes a sound-absorbing layer and a breathable layer, the sound-absorbing block material includes at least two sound-absorbing layers and at least three breathable layers, the breathable layers and the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, the outermost layer of the sound-absorbing block material is the breathable layer, and the adjacent sound-absorbing layers and the breathable layers are bonded and fixed by gluing or hot-melt processes; wherein the sound-absorbing layer is made by mixing sound-absorbing material powder, adhesive and thickener according to the mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively; the breathable layer is made of a porous breathable material. The sound-absorbing layer is distributed inside and on the surface of the sound-absorbing block material, and there can be at least one breathable layer inside at the same time, which effectively solves the problem that the interior of the sound-absorbing block material is closed and does not exchange with the air. The breathable layer and the sound-absorbing layer are bonded together by gluing or hot-melt bonding, which improves the overall strength of the sound-absorbing block material and effectively avoids the risk of possible breakage of the sound-absorbing block material. When the sound-absorbing block material is filled into the cavity of the sound-emitting device, the surface breathable layer also provides an air exchange layer and a protective layer for the sound-absorbing block material, which effectively improves the service life and sound absorption performance of the sound-absorbing block material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0027] Figure 1 A schematic diagram of the structure of a sound-absorbing block material provided by an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a sound-absorbing block material having multiple air-permeable layers in the middle provided by an embodiment of the present invention;

[0029] Figure 3 A schematic structural diagram of a comparative example sound-absorbing block material provided in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the structure of a sound-generating device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1 As shown, an embodiment of the present invention provides a sound-absorbing block material 100, wherein the sound-absorbing block material 100 comprises at least two sound-absorbing layers 1 and at least three air-permeable layers 2, wherein: Figure 1 The sound-absorbing block material 100 shown comprises two sound-absorbing layers 1 and three air-permeable layers 2, wherein the air-permeable layers 2 and the sound-absorbing layers 1 are alternately stacked in sequence to form a multi-layer structure, wherein the outermost layer of the sound-absorbing block material 100 is the air-permeable layer 2, and the adjacent sound-absorbing layers 1 and the air-permeable layers 2 are bonded and fixed by a gluing or hot-melt process;

[0033] The sound-absorbing layer 1 is made of a mixture of sound-absorbing material powder, adhesive and thickener in a mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively. The sound-absorbing layer 1 plays a role in adsorbing and desorbing air, can effectively reduce the resonant frequency of the sound-generating device, play a role in sound absorption, and is a functional unit of the sound-absorbing block 100; wherein,

[0034] The air-permeable layer 2 is made of a porous air-permeable material, and plays a role in air permeability and sound absorption. The air-permeable layer 2 is soft and elastic, and can enhance the stability of the sound-absorbing block material 100 and prevent the sound-absorbing block material 100 from breaking.

[0035] The air permeable layer 2 covering the outside of the sound absorbing block 100 can also prevent the sound absorbing block 100 from colliding with other components of the sound-generating device and causing powder to fall off.

[0036] For further information, please refer to Figure 2 As shown, it shows that the sound-absorbing block material 100 has two air-permeable layers 2 in the middle, and the whole includes four air-permeable layers 2. The air-permeable layer 2 in the middle of the sound-absorbing block material 100 increases the contact area between the sound-absorbing powder particles inside the sound-absorbing block material 100 and the air, enhances the gas exchange of the sound-absorbing block material 100, and improves the sound absorption performance of the sound-absorbing block material 100. The porous structure of the air-permeable layer 2 itself also has a certain sound absorption effect, which can further improve the acoustic performance of the sound-absorbing block material 100.

[0037] In order to minimize the space occupied by the cavity in the sound-generating device and ensure that the sound-absorbing block 100 has good acoustic performance, the thickness of the air-permeable layer 2 is in the range of 0.1-2 mm, and the thickness of the sound-absorbing layer 1 is in the range of 0.1-5 mm. Figure 2The multi-layer structure shown can adjust the number of layers and specific thickness of the sound-absorbing block material 100 according to the actual performance of a specific sound-emitting device. Preferably, when the number of air-permeable layers 2 inside the sound-absorbing block material 100 is sufficient, the thickness range of the sound-absorbing layer 1 is further reduced to 0.1-2 mm.

[0038] Preferably, the air permeable layer 2 is softened by heat through a hot-melt process and then bonded to the sound-absorbing layer 1 , and the hot-melt temperature is 100-200° C.

[0039] Preferably, the air permeable layer 2 is coated with adhesive and then bonded to the sound absorbing layer 1 , and the adhesive is at least one of polyacrylate, epoxy resin, polyurethane and silicone adhesives.

[0040] Preferably, the sound absorbing material powder is a zeolite material, the zeolite material is at least one of MFI, MEL, and FER, and the particle size of the zeolite material is less than 10 μm.

[0041] Preferably, the adhesive is at least one of polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethylvinyl acetate.

[0042] Preferably, the thickener is at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol.

[0043] Preferably, the porous breathable material is at least one of melamine foam, polyurethane foam, EVA foam and EPDM foam having an open-pore structure.

[0044] Preferably, the porous breathable material is made of interwoven fiber filaments with an interconnected structure, and the fiber filaments are at least one of cotton fiber, polyester fiber, polyethylene fiber, and polyacrylonitrile fiber.

[0045] The embodiment of the present invention further provides a method for preparing the sound-absorbing block material 100 as described in the above embodiment, and the preparation method comprises the following steps:

[0046] The sound absorbing material powder, adhesive, thickener and water are mixed in a mass ratio of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts respectively to prepare a sound absorbing material slurry;

[0047] The sound absorbing material slurry is prepared into a sound absorbing layer 1 by a low temperature drying process;

[0048] At least three prepared breathable layers 2 and at least two prepared sound-absorbing layers 1 are alternately stacked in sequence to form a multi-layer structure, so that the outermost layer after stacking is the breathable layer 2, and the adjacent breathable layers 2 and the sound-absorbing layers 1 are bonded and fixed by a gluing or hot-melt process to prepare the sound-absorbing block material 100.

[0049] Exemplarily, based on the method for preparing the sound-absorbing block material 100 provided in the embodiment of the present invention, with reference to the materials in the above embodiment, the present invention provides the following two available preparation processes:

[0050] Method 1: 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate and 100 parts of water are mixed evenly to obtain a sound-absorbing material slurry, and molded into a certain thickness. A sound-absorbing layer 1 with a thickness of 2 mm is obtained through a low-temperature drying process. The sound-absorbing layer 1 and 0.2 mm melamine foam are stacked into a slurry as shown in the following figure. Figure 1 The structure shown is heated to 160° C. to melt and soften to form a breathable layer 2, which is then adhered to the sound-absorbing layer 1 to prepare the sound-absorbing block material 100.

[0051] Method 2: 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate and 100 parts of water are mixed evenly to obtain a sound-absorbing material slurry, and molded into a certain thickness. A sound-absorbing layer 1 with a thickness of 2 mm is obtained by a low-temperature drying process. The sound-absorbing layer 1 and the breathable layer 2 composed of a 0.1 mm cotton fiber layer are stacked as follows: Figure 2 The structure shown is added with acrylic adhesive to make the sound absorbing layer 1 and the air permeable layer 2 adhere and fix to obtain the sound absorbing block material 100.

[0052] The embodiment of the present invention further provides a sound generating device 300, such as Figure 4 As shown, the sound-generating device 300 includes a housing 4 having a receiving space, and a sound-generating unit 3 received in the receiving space, wherein the sound-generating unit 3 and the housing 4 are arranged to form a rear cavity 5, wherein the rear cavity 5 is filled with the sound-absorbing block material ( Figure 4 China-Israel Figure 1 The sound absorbing block 100 shown is taken as an example).

[0053] Preferably, the outermost air permeable layer 2 of the sound absorbing block material 100 is in contact with the inner wall of the rear cavity 5 , and the sound absorbing block material 100 is squeezed and fixed in the rear cavity 5 by the inner wall of the shell 4 .

[0054] In the embodiment of the present invention, the acoustic performance test and drop test are performed on the above-mentioned sound-generating device 300 and the sound-absorbing block material 100 of different structures prepared from different raw materials. The test cavity is 1cc, and the sound-absorbing block material 100 is filled in the rear cavity 5 of the sound-generating device 300, and the test is performed by 50 times of 1m height machine free drop test. Among them, the sound-absorbing block material 100 prepared by the above-mentioned preparation method 1 is placed in a cavity with a thickness of 4.5mm. When the sound-generating device 300 is assembled, the sound-absorbing block material 100 is fixed in the rear cavity 5 by the pressing effect of the shell 4; the sound-absorbing block material 100 prepared by the above-mentioned preparation method 2 is placed in a cavity with a thickness of 3.2mm.

[0055] At the same time, the present invention also provides a comparative example of a sound-absorbing block material 200, the preparation method of which is as follows:

[0056] The sound-absorbing material slurry is uniformly mixed with 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate and 100 parts of water in a mass ratio, and molded into a certain thickness. A sound-absorbing layer 1 with a thickness of 4 mm is obtained through a low-temperature drying process. The sound-absorbing layer 1 and 0.2 mm of melamine foam are stacked into Figure 3 The structure shown is heated to 160° C. to melt and soften the air-permeable layer 2, so that it adheres to the sound-absorbing layer 1 to obtain a sound-absorbing block 200, and the sound-absorbing block 200 is placed in a cavity with a thickness of 4.2 mm.

[0057] The test results are shown in Table 1 below.

[0058] Table 1 Acoustic and drop test results of sound-absorbing blocks

[0059]

[0060] It can be seen that different air permeability and sound absorption effects can be achieved by combining different numbers of air permeable layers and sound absorbing layers. Figure 2 The acoustic performance of the sound-absorbing block prepared by method 1 is better than that of method 2 ( Figure 1 ), because there are two air permeable layers inside the block, the block has better air permeability, the sound-absorbing powder can fully exert its performance, and the performance is better; compared with the comparative example ( Figure 3 ), the sound-absorbing blocks prepared by different methods in the embodiments of the present invention are superior to the comparative examples in terms of performance and strength, and the multilayer sound-absorbing blocks provided by the present invention have a simple preparation process and low cost.

[0061] Compared with the related art, the sound-absorbing block material provided by the present invention includes a sound-absorbing layer and a breathable layer, the sound-absorbing block material includes at least two sound-absorbing layers and at least three breathable layers, the breathable layers and the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, the outermost layer of the sound-absorbing block material is the breathable layer, and the adjacent sound-absorbing layers and the breathable layers are bonded and fixed by gluing or hot-melt processes; wherein the sound-absorbing layer is made by mixing sound-absorbing material powder, adhesive and thickener according to the mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively; the breathable layer is made of a porous breathable material. The sound-absorbing layer is distributed inside and on the surface of the sound-absorbing block material, and there can be at least one breathable layer inside at the same time, which effectively solves the problem that the interior of the sound-absorbing block material is closed and does not exchange with the air. The breathable layer and the sound-absorbing layer are bonded together by gluing or hot-melt bonding, which improves the overall strength of the sound-absorbing block material and effectively avoids the risk of possible breakage of the sound-absorbing block material. When the sound-absorbing block material is filled into the cavity of the sound-emitting device, the surface breathable layer also provides an air exchange layer and a protective layer for the sound-absorbing block material, which effectively improves the service life and sound absorption performance of the sound-absorbing block material.

[0062] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A sound-absorbing block, characterized in that: The sound-absorbing block material comprises at least two sound-absorbing layers and at least three air-permeable layers, wherein the air-permeable layers and the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, wherein the outermost layer of the sound-absorbing block material is the air-permeable layer, and the adjacent sound-absorbing layers and the air-permeable layers are bonded and fixed by means of gluing or hot-melt processes; wherein, The sound absorbing layer is made by mixing sound absorbing material powder, adhesive and thickener in a mass ratio of 100 parts, 1-10 parts and 1-10 parts respectively; The air-permeable layer is made of porous air-permeable material.

2. The sound-absorbing block according to claim 1, characterized in that: The thickness of the air permeable layer is in the range of 0.1-2 mm, and the thickness of the sound absorbing layer is in the range of 0.1-5 mm.

3. The sound absorbing block according to claim 2, characterized in that: The thickness of the sound absorbing layer is in the range of 0.1-2 mm.

4. The sound absorbing block according to claim 1, characterized in that: The air permeable layer is softened by heat through a hot-melt process and then bonded to the sound-absorbing layer, and the hot-melt temperature is 100-200°C.

5. The sound absorbing block according to claim 1, characterized in that: The air permeable layer is coated with adhesive and then bonded to the sound absorbing layer. The adhesive is at least one of polyacrylate, epoxy resin, polyurethane and silicone adhesives.

6. The sound absorbing block according to claim 1, characterized in that: The sound absorbing material powder is a zeolite material, the zeolite material is at least one of MFI, MEL and FER, and the particle size of the zeolite material is less than 10 μm.

7. The sound absorbing block according to claim 1, characterized in that: The adhesive is at least one of polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethyl vinyl acetate.

8. The sound absorbing block according to claim 1, characterized in that: The thickener is at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol.

9. The sound absorbing block according to claim 4, characterized in that: The porous breathable material is at least one of melamine foam, polyurethane foam, EVA foam and EPDM foam with an open-pore structure.

10. The sound absorbing block according to claim 5, characterized in that: The porous breathable material is made of interwoven fiber filaments with an interconnected structure, and the fiber filaments are at least one of cotton fiber, polyester fiber, polyethylene fiber, and polyacrylonitrile fiber.

11. A method for preparing a sound-absorbing block according to any one of claims 1 to 10, characterized in that: The preparation method comprises the following steps: The sound absorbing material powder, adhesive, thickener and water are mixed in a mass ratio of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts respectively to prepare a sound absorbing material slurry; The sound absorbing material slurry is prepared into a sound absorbing layer by a low temperature drying process; The prepared at least three layers of breathable layers and at least two layers of the sound-absorbing layers are alternately stacked in sequence to form a multi-layer structure, so that the outermost layer after stacking is the breathable layer, and the adjacent breathable layers and the sound-absorbing layers are bonded and fixed by a gluing or hot-melt process to prepare the sound-absorbing block material.

12. A sound-generating device, characterized in that: The sound-generating device comprises a shell having a receiving space, and a sound-generating unit received in the receiving space, wherein the sound-generating unit and the shell are arranged to form a rear cavity, wherein the rear cavity is filled with the sound-absorbing block material according to any one of claims 1 to 10.

13. The sound generating device according to claim 12, characterized in that: The air permeable layer of the outermost layer of the sound-absorbing block material contacts the inner wall of the rear cavity, and the sound-absorbing block material is pressed and fixed in the rear cavity through the inner wall of the shell.

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