Sound-absorbing block and preparation method therefor, and sound production device
By designing a multi-layered sound-absorbing block, the problems of easy powder shedding and poor air permeability of sound-absorbing materials are solved, achieving efficient sound absorption and long-life sound absorption effects, and simplifying the process.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- AAC MICROTECH (CHANGZHOU) CO LTD
- Filing Date
- 2025-01-22
- Publication Date
- 2026-07-30
AI Technical Summary
Existing sound-absorbing materials are prone to powdering and breakage in sound-generating devices, and the blocks have poor air permeability, resulting in low sound absorption efficiency and short service life.
The sound-absorbing block adopts a multi-layer structure, including at least two sound-absorbing layers and at least three breathable layers. The breathable layers and sound-absorbing layers are stacked alternately and fixed by adhesive or hot-melt process. The sound-absorbing layer is made of a mixture of sound-absorbing material powder, adhesive and thickener, and the breathable layer is made of porous material.
It improves sound absorption performance and service life, avoids breakage of sound-absorbing blocks, enhances air exchange capacity, simplifies the process, and reduces costs.
Smart Images
Figure CN2025074058_30072026_PF_FP_ABST
Abstract
Description
Sound-absorbing blocks and their preparation methods, sound-generating devices Technical Field
[0001] This invention relates to the field of sound-generating device technology, and more particularly to a sound-absorbing block material, its preparation method, and a sound-generating device. Background Technology
[0002] In the field of acoustics, to improve the audio quality of various mobile terminals, a common practice is to fill the rear cavity of the sound-generating device with sound-absorbing material to reduce the resonant frequency and achieve a physically larger rear cavity volume. Technical issues
[0003] The sound-absorbing materials commonly used in small cavities are molecular sieves with nanoscale microporous structures. In terms of process, molecular sieves are often formed into particles of a certain size and then filled into the rear cavity of the sound-generating device to play a sound-absorbing role.
[0004] However, sound-absorbing particles can shed powder and break when they collide with each other. Furthermore, static electricity during particle filling makes packing difficult. Another related solution is to mold zeolite into blocks, eliminating the need for complex granulation processes. This method is simple and reduces the risk of breakage from particle collisions. However, the blocks are larger, resulting in reduced strength. As the thickness increases, the blocks become less permeable, preventing the sound-absorbing powder inside from effectively absorbing sound and reducing the overall sound absorption efficiency. When these blocks are used in the rear cavity of a loudspeaker, they come into direct contact with the hard inner wall of the cavity, leading to collisions and friction that easily cause breakage and powder shedding.
[0005] Therefore, it is necessary to provide a new sound-absorbing block material to solve the above problems. Technical solutions
[0006] The technical problem to be solved by the present invention is to provide a sound-absorbing block material with good sound absorption performance and easy application, as well as its preparation method and sound-generating device.
[0007] To solve the above-mentioned technical problems, the present invention provides a sound-absorbing block material, which includes at least two sound-absorbing layers and at least three breathable layers. The breathable layers and the sound-absorbing layers are stacked alternately to form a multi-layer structure. The outermost layer of the sound-absorbing block material is the breathable layer, and adjacent sound-absorbing layers and breathable layers are bonded and fixed together by adhesive bonding or hot-melt bonding processes.
[0008] The sound-absorbing layer is made by mixing sound-absorbing material powder, adhesive and thickener in mass ratios of 100 parts, 1-10 parts and 1-10 parts respectively.
[0009] The breathable layer is made of a porous breathable material.
[0010] Preferably, the thickness of the breathable 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 breathable layer is bonded to the sound-absorbing layer after being softened by heat through a hot-melt process, with the hot-melt temperature being 100-200℃.
[0013] Preferably, the breathable layer is bonded to the sound-absorbing layer after being coated with adhesive, 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, and 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 selected from polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethyl ethylene acetate salt.
[0016] Preferably, the thickener is at least one of sodium alginate, sodium carboxymethyl cellulose, and polyvinyl alcohol.
[0017] Preferably, the porous breathable material is at least one of melamine foam, polyurethane foam, EVA foam, and EPDM foam with an open-pore structure.
[0018] Preferably, the porous breathable material is made of interwoven fiber filaments with an interconnected structure, wherein 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] A sound-absorbing material slurry was prepared by mixing sound-absorbing material powder, adhesive, thickener and water in mass ratios of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts, respectively.
[0021] The sound-absorbing material slurry is prepared into a sound-absorbing layer by a low-temperature drying process.
[0022] At least three breathable layers and at least two sound-absorbing layers are stacked alternately to form a multi-layer structure, such that the outermost layer after stacking is a breathable layer. Adjacent breathable layers and sound-absorbing layers are bonded and fixed together by adhesive bonding or hot-melt process to prepare the sound-absorbing block.
[0023] The present invention also provides a sound-generating device, the sound-generating device comprising a housing having a receiving space and a sound-generating unit housed within the receiving space, the sound-generating unit and the housing forming a rear cavity, wherein the rear cavity is filled with the sound-absorbing block material as described above.
[0024] Preferably, the outermost breathable layer of the sound-absorbing block is in contact with the inner wall of the rear cavity, and the sound-absorbing block is pressed and fixed in the rear cavity by the inner wall of the housing. Beneficial effects
[0025] Compared with related technologies, 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 stacked alternately to form a multi-layer structure. The outermost layer of the sound-absorbing block material is the breathable layer. Adjacent sound-absorbing layers and breathable layers are bonded and fixed together by adhesive or hot-melt processes. 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 breathable layer is made of porous breathable material. The sound-absorbing layer is distributed inside and on the surface of the sound-absorbing block. At least one breathable layer can exist inside at the same time, which effectively solves the problem of the sound-absorbing block being closed and not exchanging gas with the air. The breathable layer and the sound-absorbing layer are bonded together by adhesive or hot melt bonding, which improves the overall cavity of the sound-absorbing block and effectively avoids the risk of breakage of the sound-absorbing block. When the sound-absorbing block is filled into the cavity of the sound-generating device, the surface breathable layer also provides an air exchange layer and a protective layer for the sound-absorbing block, which effectively improves the service life and sound absorption performance of the sound-absorbing block. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. 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 effort, wherein:
[0027] Figure 1 is a structural schematic diagram of the sound-absorbing block provided in an embodiment of the present invention;
[0028] Figure 2 is a schematic diagram of the structure of the sound-absorbing block material with multiple breathable layers in the middle provided in an embodiment of the present invention;
[0029] Figure 3 is a structural schematic diagram of the sound-absorbing block provided in the embodiment of the present invention;
[0030] Figure 4 is a schematic diagram of the structure of the sound-generating device provided in an embodiment of the present invention. Embodiments of the present invention
[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] Please refer to Figure 1. This embodiment of the invention provides a sound-absorbing block 100, which includes at least two sound-absorbing layers 1 and at least three breathable layers 2. The sound-absorbing block 100 shown in Figure 1 includes two sound-absorbing layers 1 and three breathable layers 2. The breathable layers 2 and the sound-absorbing layers 1 are stacked alternately to form a multi-layer structure. The outermost layer of the sound-absorbing block 100 is the breathable layer 2. Adjacent sound-absorbing layers 1 and breathable layers 2 are bonded and fixed together by adhesive bonding or hot-melt bonding processes.
[0033] The sound-absorbing layer 1 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 sound-absorbing layer 1 functions to adsorb and desorb air, effectively reducing the resonant frequency of the sound-generating device and exerting its sound-absorbing effect; it is the functional unit of the sound-absorbing block 100.
[0034] The breathable layer 2 is made of porous breathable material. The breathable layer 2 plays the role of breathability and sound absorption. The breathable layer 2 is soft and elastic, which can enhance the stability of the sound-absorbing block 100 and prevent the sound-absorbing block 100 from breaking.
[0035] The breathable layer 2 covering the outside of the sound-absorbing block 100 can also prevent the sound-absorbing block 100 from colliding with other parts of the sound-generating device, which would cause powder to fall off.
[0036] Furthermore, please refer to Figure 2, which shows the structure of the sound-absorbing block 100, which has two breathable layers 2 in the middle and comprises four breathable layers 2 in total. The breathable layers 2 in the middle of the sound-absorbing block 100 increase the contact area between the sound-absorbing powder particles inside the sound-absorbing block 100 and the air, enhancing the gas exchange of the sound-absorbing block 100 and improving its sound absorption performance. The porous structure of the breathable layers 2 themselves also has a certain sound absorption effect, which can further improve the acoustic performance of the sound-absorbing block 100.
[0037] To minimize the space occupied by the cavity in the sound-generating device while ensuring good acoustic performance of the sound-absorbing block 100, the thickness of the breathable layer 2 ranges from 0.1 to 2 mm, and the thickness of the sound-absorbing layer 1 ranges from 0.1 to 5 mm. As shown in Figure 2, the multi-layer structure allows for adjustments to the number of layers and the specific thickness of the sound-absorbing block 100 to suit the actual performance of the specific sound-generating device. Preferably, when the number of breathable layers 2 inside the sound-absorbing block 100 is sufficiently large, the thickness range of the sound-absorbing layer 1 can be further reduced to 0.1-2 mm.
[0038] Preferably, the breathable layer 2 is bonded to the sound-absorbing layer 1 after being softened by heat through a hot-melt process, with the hot-melt temperature being 100-200℃.
[0039] Preferably, the breathable layer 2 is bonded to the sound-absorbing layer 1 after being coated with adhesive, 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, and 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 selected from polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethyl ethylene acetate salt.
[0042] Preferably, the thickener is at least one of sodium alginate, sodium carboxymethyl cellulose, and polyvinyl alcohol.
[0043] Preferably, the porous breathable material is at least one of melamine foam, polyurethane foam, EVA foam, and EPDM foam with an open-pore structure.
[0044] Preferably, the porous breathable material is made of interwoven fiber filaments with an interconnected structure, wherein the fiber filaments are at least one of cotton fiber, polyester fiber, polyethylene fiber, and polyacrylonitrile fiber.
[0045] This invention also provides a method for preparing the sound-absorbing block 100 as described in the above embodiments, the method comprising the following steps:
[0046] A sound-absorbing material slurry was prepared by mixing sound-absorbing material powder, adhesive, thickener and water in mass ratios of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts, respectively.
[0047] The sound-absorbing material slurry is prepared into a sound-absorbing layer 1 by a low-temperature drying process;
[0048] At least three breathable layers 2 and at least two sound-absorbing layers 1 are stacked alternately to form a multi-layer structure, such that the outermost layer after stacking is a breathable layer 2. The adjacent breathable layers 2 and sound-absorbing layers 1 are bonded and fixed by adhesive bonding or hot melting process to prepare the sound-absorbing block 100.
[0049] For example, based on the method for preparing the sound-absorbing block 100 provided in the embodiments of the present invention, and referring to the materials in the above embodiments, the present invention provides the following two available preparation processes:
[0050] Method 1: Mix 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate, and 100 parts of water in a uniform mass ratio to obtain a sound-absorbing material slurry. Mold the slurry to a certain thickness and dry it at low temperature to obtain a sound-absorbing layer 1 with a thickness of 2 mm. Stack the sound-absorbing layer 1 with 0.2 mm melamine foam to form the structure shown in Figure 1. Add the slurry to a 160°C hot melt softening process to form a breathable layer 2, which is then adhered to the sound-absorbing layer 1 to prepare the sound-absorbing block 100.
[0051] Method 2: Mix 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate, and 100 parts of water in a uniform mass ratio to obtain a sound-absorbing material slurry. Mold the slurry to a certain thickness and dry it at low temperature to obtain a sound-absorbing layer 1 with a thickness of 2 mm. Stack the sound-absorbing layer 1 with a 0.1 mm cotton fiber layer to form the structure shown in Figure 2. Add acrylic adhesive to bond and fix the sound-absorbing layer 1 and the breathable layer 2 to obtain the sound-absorbing block 100.
[0052] This invention also provides a sound-generating device 300, as shown in FIG4. The sound-generating device 300 includes a housing 4 having a receiving space and a sound-generating unit 3 received in the receiving space. The sound-generating unit 3 and the housing 4 surround to form a rear cavity 5, wherein the rear cavity 5 is filled with the sound-absorbing block material as described above (the sound-absorbing block material 100 shown in FIG1 is used as an example in FIG4).
[0053] Preferably, the outermost breathable layer 2 of the sound-absorbing block 100 is in contact with the inner wall of the rear cavity 5, and the sound-absorbing block 100 is pressed and fixed in the rear cavity 5 by the inner wall of the housing 4.
[0054] This invention presents acoustic performance tests and drop tests on the aforementioned sound-generating device 300 and sound-absorbing blocks 100 with different structures prepared from different raw materials. The test chamber is 1cc, and the sound-absorbing blocks 100 are filled in the rear cavity 5 of the sound-generating device 400. The devices undergo 50 free-fall drops from a height of 1m. Specifically, the sound-absorbing blocks 100 prepared using method one are placed in a cavity with a thickness of 4.5mm. During the assembly of the sound-generating device 400, the sound-absorbing blocks 100 are fixed in the rear cavity 5 by the pressing action of the shell 4. The sound-absorbing blocks 100 prepared using method two are placed in a cavity with a thickness of 3.2mm.
[0055] Meanwhile, the present invention also provides a comparative sound-absorbing block 200, the preparation method of which is as follows:
[0056] A sound-absorbing material slurry is prepared by mixing 100 parts of sound-absorbing material powder, 10 parts of polyacrylate adhesive, 2 parts of sodium alginate, and 100 parts of water in a uniform mass ratio. The slurry is then molded to a certain thickness and dried at low temperature to obtain a 4mm thick sound-absorbing layer 1. The sound-absorbing layer 1 and 0.2mm of melamine foam are stacked together to form the structure shown in Figure 3. The slurry is then added to a 160℃ hot-melt softened breathable layer 2 to adhere it to the sound-absorbing layer 1, resulting in a sound-absorbing block 200. The sound-absorbing block 200 is then placed into a cavity with a thickness of 4.2mm.
[0057] The test results are shown in Table 1 below.
[0058] Table 1. Acoustic and drop test results of sound-absorbing blocks
[0059] Sample performance ΔF0 / Hz drop test method 1 182 no change method 2 198 no change Comparative example 154 fracture
[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. Among them, the acoustic performance of the sound-absorbing block prepared by method two (Figure 2) is better than that of method one (Figure 1) because there are two air permeable layers inside the block, which makes the block more breathable and allows the sound-absorbing powder to perform better. Compared with the comparative example (Figure 3), the sound-absorbing blocks prepared by different methods in the embodiments of the present invention are better than the comparative example in terms of performance and strength. Moreover, the multi-layer sound-absorbing block provided by the present invention has a simple preparation process and low cost.
[0061] Compared with related technologies, 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 stacked alternately to form a multi-layer structure. The outermost layer of the sound-absorbing block material is the breathable layer. Adjacent sound-absorbing layers and breathable layers are bonded and fixed together by adhesive or hot-melt processes. 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 breathable layer is made of porous breathable material. The sound-absorbing layer is distributed inside and on the surface of the sound-absorbing block. At least one breathable layer can exist inside at the same time, which effectively solves the problem of the sound-absorbing block being closed and not exchanging gas with the air. The breathable layer and the sound-absorbing layer are bonded together by adhesive or hot melt bonding, which improves the overall cavity of the sound-absorbing block and effectively avoids the risk of breakage of the sound-absorbing block. When the sound-absorbing block is filled into the cavity of the sound-generating device, the surface breathable layer also provides an air exchange layer and a protective layer for the sound-absorbing block, which effectively improves the service life and sound absorption performance of the sound-absorbing block.
[0062] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.
Claims
1. A sound-absorbing block material, characterized in that, The sound-absorbing block material comprises at least two sound-absorbing layers and at least three breathable layers. The breathable layers and the sound-absorbing layers are stacked alternately to form a multi-layer structure. The outermost layer of the sound-absorbing block material is the breathable layer. Adjacent sound-absorbing layers and breathable layers are bonded and fixed together by adhesive bonding or hot-melt bonding processes. The sound-absorbing layer is made by mixing sound-absorbing material powder, adhesive and thickener in mass ratios of 100 parts, 1-10 parts and 1-10 parts respectively. The breathable layer is made of a porous breathable material.
2. The sound-absorbing block material according to claim 1, characterized in that, The thickness of the breathable layer ranges from 0.1 to 2 mm, and the thickness of the sound-absorbing layer ranges from 0.1 to 5 mm.
3. The sound-absorbing block material according to claim 2, characterized in that, The thickness of the sound-absorbing layer ranges from 0.1 to 2 mm.
4. The sound-absorbing block material according to claim 1, characterized in that, The breathable layer is softened by heat through a hot-melt process and then bonded to the sound-absorbing layer at a temperature of 100-200℃.
5. The sound-absorbing block material according to claim 1, characterized in that, The breathable layer is bonded to the sound-absorbing layer after being coated with adhesive. The adhesive is at least one of polyacrylate, epoxy resin, polyurethane, and silicone adhesives.
6. The sound-absorbing block material according to claim 1, characterized in that, The sound-absorbing material powder is a zeolite material, which 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 material according to claim 1, characterized in that, The adhesive is at least one of polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethyl ethylene acetate salt.
8. The sound-absorbing block material 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 material 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 material 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 material as described in any one of claims 1-10, characterized in that, The preparation method includes the following steps: A sound-absorbing material slurry was prepared by mixing sound-absorbing material powder, adhesive, thickener and water in mass ratios of 100 parts, 1-10 parts, 1-10 parts and 80-200 parts, respectively. The sound-absorbing material slurry is prepared into a sound-absorbing layer by a low-temperature drying process. At least three breathable layers and at least two sound-absorbing layers are stacked alternately to form a multi-layer structure, such that the outermost layer after stacking is a breathable layer. Adjacent breathable layers and sound-absorbing layers are bonded and fixed together by adhesive bonding or hot-melt process to prepare the sound-absorbing block.
12. A sound-generating device, characterized in that, The sound-generating device includes a housing with a receiving space and a sound-generating unit housed within the receiving space. The sound-generating unit and the housing enclose a rear cavity, wherein the rear cavity is filled with a sound-absorbing block material as described in any one of claims 1-10.
13. The sound-generating device according to claim 12, characterized in that, The outermost breathable layer of the sound-absorbing block is in contact with the inner wall of the rear cavity, and the sound-absorbing block is pressed and fixed in the rear cavity by the inner wall of the housing.