Acoustic composite material block and electronic equipment

Abstract

The utility model relates to the technical field of acoustic materials, in particular to an acoustic composite material block and electronic equipment. The acoustic composite material block comprises a porous sound-absorbing structure and a fiber layer wrapping the outer surface of the porous sound-absorbing structure, the fiber layer is of a three-dimensional network structure, the porous sound-absorbing structure is provided with a first-level pore channel and a second-level pore channel, the first-level pore channel is communicated with the second-level pore channel, and the first-level pore channel is communicated with the second-level pore channel. And the first-stage pore channels and the second-stage pore channels are respectively communicated with the grids of the three-dimensional network structure. According to the acoustic composite material block and the electronic equipment provided by the embodiment of the invention, the possibility of powder falling of the sound absorbing material in the long-term use process is reduced, and the low-frequency acoustic effect is improved.

Description

Technical Field

[0001] This disclosure relates to the field of acoustic materials technology, and more particularly to an acoustic composite material block and an electronic device. Background Technology

[0002] With the development of multimedia devices, miniature loudspeakers have been widely used. However, due to space limitations, the increasingly smaller resonant cavities of these loudspeakers lead to higher resonant frequencies and lower low-frequency sound pressure sensitivity, making it difficult to improve their performance in the low-frequency range. Currently, the main approach to improving the low-frequency performance of miniature loudspeakers is to fill the loudspeaker cavity with sound-absorbing materials.

[0003] However, the sound-absorbing materials in the relevant technologies are not strong enough, and there is a significant risk of shedding and powdering during long-term use. This can easily contaminate the speaker cavity, affecting the normal sound output of the speaker, and may also damage other components of the speaker, reducing its service life. Utility Model Content

[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides an acoustic composite material block and an electronic device that reduces the possibility of sound-absorbing material shedding powder during long-term use and improves low-frequency acoustic performance.

[0005] According to a first aspect of this disclosure, an acoustic composite material block is provided, comprising: a porous sound-absorbing structure and a fiber layer wrapped around the outer surface of the porous sound-absorbing structure, the fiber layer having a three-dimensional mesh structure, the porous sound-absorbing structure having a first-level channel and a second-level channel, the first-level channel communicating with the second-level channel, and the first-level channel and the second-level channel also communicating with the mesh of the three-dimensional mesh structure.

[0006] According to a second aspect of this disclosure, an electronic device is provided, the electronic device having a speaker cavity filled with an acoustic composite material block of the first aspect of this disclosure.

[0007] In one or more technical solutions provided in this disclosure, the acoustic composite material block includes a porous sound-absorbing structure and a fiber layer wrapped around the outer surface of the porous sound-absorbing structure. Therefore, the fiber layer provides a protective layer for the porous sound-absorbing structure, preventing damage from external physical impacts, wear, and scratches, thus extending its service life. Simultaneously, the fiber layer has a three-dimensional mesh structure, which, wrapped around the outer surface of the porous sound-absorbing structure, provides excellent support and reinforcement. Even if the acoustic composite material block is subjected to external forces such as compression, collision, or vibration, the three-dimensional mesh structure can disperse these forces, preventing excessive compression or damage to the pores in the porous sound-absorbing structure. This reduces the possibility of sound-absorbing material shedding or powdering during long-term use.

[0008] Based on this, the porous sound-absorbing structure of this embodiment has first-level channels and second-level channels, which are connected to each other. The first-level channels and second-level channels are also connected to the mesh of the three-dimensional network structure. Therefore, the porous sound-absorbing structure in the acoustic composite block, with its first-level and second-level channels, combined with the three-dimensional network structure of the fiber layer, greatly enriches the pore size and pore size distribution. The different channels and mesh provide more adsorption sites for air molecules, allowing for sufficient adsorption and desorption, increasing the resonant frequency shift and improving the low-frequency acoustic effect. Attached Figure Description

[0009] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0010] Figure 1 This is a schematic cross-sectional view of the acoustic composite material block provided in an embodiment of this disclosure;

[0011] Figure 2 This is a scanning electron microscope image of an acoustic composite material block according to an embodiment of this disclosure;

[0012] Figure 3 This is a scanning electron microscope image of an acoustic composite material block that is a comparative example of this disclosure.

[0013] Figure label:

[0014] 110 - Porous sound-absorbing structure, 120 - Fiber layer. Detailed Implementation

[0015] To make the technical problems, technical solutions, and beneficial effects to be solved by this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0016] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise expressly and specifically defined. "Several" means one or more, unless otherwise expressly and specifically defined.

[0018] In the description of this disclosure, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0019] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0020] As electronic products such as mobile phones, tablets, and laptops become increasingly thinner and lighter, the resonant cavities of their speaker system components are also shrinking. It is well known that smaller speaker resonant cavities lead to higher resonant frequencies and lower low-frequency sound pressure sensitivity, while consumers' demands for audio quality in these products are constantly increasing. To resolve this contradiction, sound-absorbing particles made of porous powder material are filled into the rear acoustic cavity of the speaker module. The special physical channel structure within the porous material allows for rapid adsorption and desorption of gas within the rear acoustic cavity, virtually enlarging the resonant space of the speaker's rear acoustic cavity. This effectively lowers the speaker's resonant frequency and improves low-frequency sensitivity. The filling volume of the sound-absorbing particles accounts for 70% to 90% of the total volume of the rear cavity, and these particles are fluid within the rear acoustic cavity.

[0021] However, under large amplitude operating conditions, the sound-absorbing particles in the rear acoustic cavity of the loudspeaker vibrate violently, and the sound-absorbing particles rub and collide violently with each other or with the cavity wall, causing the sound-absorbing particles to break. The powder generated by the breakage of the sound-absorbing particles enters the interior of the loudspeaker unit, causing pollution and leading to problems such as failure of its acoustic performance.

[0022] To address the aforementioned problems, this disclosure provides an acoustic composite material block and an electronic device that reduces the possibility of sound-absorbing material shedding powder during long-term use and improves low-frequency acoustic performance. The electronic device may include at least one of a smartphone, tablet, laptop, and smartwatch.

[0023] Figure 1 A cross-sectional structural schematic diagram of the acoustic composite material block provided in an embodiment of this disclosure is shown. For example... Figure 1 As shown, the acoustic composite material block of this embodiment includes a porous sound-absorbing structure 110 and a fiber layer 120 wrapped around the outer surface of the porous sound-absorbing structure 110. The fiber layer 120 has a three-dimensional mesh structure.

[0024] In practical applications, the fiber layer 120 provides a protective layer for the porous sound-absorbing structure 110, preventing damage from external physical impacts, wear, and scratches, thus extending its service life. Simultaneously, the fiber layer 120 has a three-dimensional mesh structure that wraps around the outer surface of the porous sound-absorbing structure 110, providing excellent support and reinforcement. Even if the acoustic composite material block is subjected to external forces such as compression, collision, or vibration, the three-dimensional mesh structure can disperse these forces, preventing excessive compression or damage to the pores in the porous sound-absorbing structure 110. This reduces the possibility of sound-absorbing material shedding or powdering during long-term use.

[0025] It is understood that the fibers in the fiber layer 120 include at least one of bonding fibers, supporting fibers, wave-transparent fibers, and heat-shrinkable fibers.

[0026] The aforementioned bonding fibers may include at least one of polyvinyl alcohol fibers, polyethylene fibers, polyethylene fiber pulp, polypropylene fibers, acrylic fiber pulp, polyester fibers, and polyester fiber pulp.

[0027] The supporting fiber may include at least one of glass fiber cotton, aramid pulp, polyethylene terephthalate precipitated fiber and poly(p-phenylene benzodioxazole) fiber.

[0028] For microwave-transparent fibers, they may include at least one of poly(p-phenylenebenzodioxazole) fiber, quartz fiber, aramid 1313, silica fiber, aramid 1414, aramid pulp, aramid precipitated fiber, polyimide fiber, and boron nitride microwave-transparent fiber.

[0029] For heat-shrinkable fibers, they may include at least one of polyphenylene sulfide fibers, nylon fibers, polyethylene fibers, polypropylene fibers, and polyester fibers.

[0030] For example, the aforementioned heat-shrinkable fiber exhibits a dry heat shrinkage rate of 30% to 50% within a temperature range of 90℃ to 180℃, a breaking elongation ≥30%, and a breaking strength ≥2cN / dtex. Within this temperature range, the length of the heat-shrinkable fiber is significantly reduced. Therefore, when the fiber layer contains heat-shrinkable fibers, it allows the fiber layer to more tightly encapsulate the porous sound-absorbing structure after heating, thus more firmly fixing the fiber layer and the porous sound-absorbing structure together. Within this range of breaking elongation and breaking strength, the acoustic composite block can withstand a certain amount of tensile force when subjected to external forces, exhibiting good flexibility and extensibility, and can be stretched to a certain extent without easily breaking.

[0031] For example, the porous sound-absorbing structure 110 described above has a first-level channel and a second-level channel, the first-level channel and the second-level channel are connected, and the first-level channel and the second-level channel are also connected to the mesh of the three-dimensional mesh structure respectively.

[0032] In practical applications, the porous sound-absorbing structure 110 in the acoustic composite block has first-level and second-level channels, plus the three-dimensional network structure of the fiber layer, which greatly enriches the pore size and pore size distribution. Different channels and grids provide more adsorption sites for air molecules, allowing air molecules to be fully adsorbed and desorbed, increasing the resonant frequency shift value and improving the low-frequency acoustic effect.

[0033] In one feasible embodiment, in the porous sound-absorbing structure of this disclosure, the first-level channels account for 8% to 10% of the volume of the porous sound-absorbing structure, and the second-level channels account for 15% to 20% of the volume. Therefore, a reasonable volume ratio allows the porous sound-absorbing structure to maintain good sound absorption performance while possessing sufficient structural strength. The ratio of the first-level and second-level channels is carefully designed so that the pore distribution within the material of the porous sound-absorbing structure is neither too dense, leading to fragility, nor too sparse, affecting the sound absorption effect. Simultaneously, a suitable pore volume ratio can reduce the risk of channel collapse during use. If the pore volume is too large, the material of the porous sound-absorbing structure is prone to deformation or even collapse under external forces, thereby affecting the sound absorption performance and the service life of the porous sound-absorbing structure. Therefore, by controlling the volume ratio of the first-level and second-level channels, the stress distribution within the material can be made more uniform, reducing the possibility of channel collapse.

[0034] In one possible implementation, the porous sound-absorbing structure of this disclosure includes fibers and sound-absorbing particles bonded together, with first-order channels formed between the fibers and the sound-absorbing particles, as well as between the particles themselves.

[0035] It is understood that the fibers in the aforementioned porous sound-absorbing structure include supporting fibers, bonding fibers, and wave-transparent fibers. The specific types of supporting fibers, bonding fibers, and wave-transparent fibers in the porous sound-absorbing structure are the same as those in the aforementioned fiber layer, and will not be elaborated here.

[0036] In practical applications, the supporting fibers in the aforementioned porous sound-absorbing structure primarily provide structural support for the sound-absorbing particles, ensuring that the acoustic composite block possesses sufficient mechanical strength during use and can maintain its shape and integrity. The bonding fibers in the porous sound-absorbing structure are responsible for effectively binding the various components together, forming a unified structure and preventing component separation during use. The wave-transmitting fibers help ensure that sound waves can pass smoothly through the porous sound-absorbing structure, significantly influencing its performance in acoustic environments.

[0037] Building upon this foundation, the porous sound-absorbing structure comprises fibers and sound-absorbing particles interwoven at the microscopic level, forming first-order channels. The fibers act as a framework, supporting the sound-absorbing particles while simultaneously creating gaps between them; these gaps are a crucial component of the first-order channels. Simultaneously, the sound-absorbing particles themselves naturally form pores between each other. These pores, along with the pores between the fibers and the sound-absorbing particles, collectively constitute the first-order channels. The presence of these first-order channels significantly increases the specific surface area of ​​the porous sound-absorbing structure, meaning it possesses more adsorption sites and can adsorb more gas molecules. These gas molecules vibrate under the influence of sound waves, increasing their interaction with the sound waves and thus enhancing the sound absorption effect.

[0038] For example, the first-level channels in this embodiment include first micrometer-level channels and first millimeter-level channels. The pore size of the first micrometer-level channels is 0.08 μm to 30 μm, and the pore size of the first millimeter-level channels is 0.08 mm to 2 mm. Preferably, the pore size of the first micrometer-level channels is 0.1 μm to 25 μm, and the pore size of the first millimeter-level channels is 0.1 mm to 1.8 mm. It should be understood that the pore sizes of the first micrometer-level channels and the first millimeter-level channels can be adjusted by controlling the fiber length and the particle size of the sound-absorbing particles.

[0039] The aforementioned first-level channels simultaneously include micrometer-scale and millimeter-scale channels. This multi-scale pore size distribution enables the material to achieve synergistic sound absorption across different frequency ranges, broadening the sound absorption frequency range of the porous sound-absorbing structure. For example, micrometer-scale channels primarily function for high-frequency sound waves. High-frequency sound waves have short wavelengths, and when they enter these tiny channels, they are rapidly attenuated due to reflection and scattering from the pore walls, as well as friction with air molecules within the channels. Millimeter-scale channels, on the other hand, focus on absorbing low-frequency sound waves. Low-frequency sound waves have longer wavelengths and require greater space for effective energy attenuation. These relatively larger channels provide sufficient space for low-frequency sound waves to resonate and reflect within the channels. Therefore, the simultaneous presence of micrometer-scale and millimeter-scale channels allows the porous sound-absorbing structure to function effectively across a wider frequency range, thus meeting the sound absorption requirements of different acoustic environments.

[0040] In one example, in the first-stage channels of this disclosure embodiment, the volume ratio of the first micrometer-level channel to the first millimeter-level channel is (36-40):(58-63). This volume range allows the acoustic composite material block to exert its sound absorption effect over a wider frequency range. If the proportion of micrometer-level channels is too high, it may lead to insufficient absorption of low-frequency sound waves; conversely, if the proportion of millimeter-level channels is too high, it may affect the processing effect of high-frequency sound waves. This volume ratio range ensures that the material has good sound absorption performance in the frequency range from hundreds of hertz to thousands of hertz and even higher, meeting the absorption needs of different frequencies of sound in various application scenarios.

[0041] In one possible implementation, the sound-absorbing particles of this disclosure comprise a porous material having pores that form secondary channels. It should be understood that the sound-absorbing particles comprise at least one of zeolite molecular sieves, activated silica, activated carbon, calcium carbonate, calcium silicate, alumina, hydrogels, and aerogels.

[0042] The aforementioned zeolite molecular sieves may include at least one of the following: MFI structured molecular sieves, FER structured molecular sieves, CHA structured molecular sieves, MEL structured molecular sieves, TON structured molecular sieves, and MTT structured molecular sieves.

[0043] In practical applications, at least one of the above-mentioned zeolite molecular sieves, activated silica, activated carbon, calcium carbonate, calcium silicate, alumina, hydrogel and aerogel with pores can be directly purchased as sound-absorbing particles. The secondary channels formed by the pores can further increase the specific surface area of ​​the porous sound-absorbing structure, which can adsorb more gas molecules and improve the acoustic effect.

[0044] For example, the aforementioned second-level channels include nanoscale channels, second micrometer-scale channels, and second millimeter-scale channels. The pore size of the nanoscale channels is 0.2 nm to 100 nm, the pore size of the second micrometer-scale channels is 0.1 μm to 80 μm, and the pore size of the second millimeter-scale channels is 0.08 mm to 2 mm. Preferably, the pore size of the nanoscale channels is 0.5 nm to 90 nm, the pore size of the second micrometer-scale channels is 0.2 μm to 75 μm, and the pore size of the second millimeter-scale channels is 0.1 mm to 0.18 mm. The coexistence of these three different scales of channels forms a full-frequency sound absorption coverage from ultra-high frequencies to low frequencies. Sound waves of different frequencies can find suitable sound absorption mechanisms in their corresponding channels, working synergistically to enable the acoustic composite material block to exhibit excellent sound absorption performance over an extremely wide frequency range.

[0045] It is understood that at least one of the following—zeolite molecular sieves, activated silica, activated carbon, calcium carbonate, calcium silicate, alumina, hydrogels, and aerogels—that meet the above-mentioned nanoscale, second micrometer-scale, and second millimeter-scale pore sizes can be directly purchased as sound-absorbing particles for use in the embodiments of this disclosure.

[0046] In one example, the volume ratio of the nano-sized channels, the second micrometer-sized channels, and the second millimeter-sized channels in the aforementioned second-level channels is (18–30):(25–33):(37–57). This synergistic effect of the three volume ratios allows the acoustic composite material block to achieve efficient sound absorption in the corresponding channels across the entire frequency range, from ultra-high frequencies to low frequencies, precisely balancing the sound absorption effect of different frequency sound waves. This enables the acoustic composite material block to exhibit excellent sound absorption performance in complex and varied acoustic environments.

[0047] For example, the thickness of the fiber layer in this embodiment is 0.1 mm to 0.2 mm. A fiber layer thickness of 0.1 mm to 0.2 mm ensures that there is enough fiber to increase the contact area between the sound waves and the porous sound-absorbing structure, while avoiding excessive thickness that would make it difficult for the sound waves to penetrate the porous sound-absorbing structure.

[0048] The shape of the acoustic composite material block in this embodiment can be set according to the cavity structure of the loudspeaker. The shape of the acoustic composite material block includes a cylinder, cuboid, cube, or irregular shape. Therefore, the acoustic composite material block in this embodiment can be directly filled into the loudspeaker, and the large amount of air adsorption and desorption virtually enlarges the rear cavity of the loudspeaker, thereby improving the low-frequency acoustic effect.

[0049] In practical applications, the preparation method of the acoustic composite material block according to this disclosure includes: First, at least one of the supporting fibers, bonding fibers, wave-transparent fibers, and heat-shrinkable fibers can be transferred to a carding machine, water can be injected, and the mixture can be carded and dispersed for 20 to 50 minutes to obtain a functional fiber dispersion. Then, the dispersion is formed by wet papermaking to obtain a fiber layer. Next, the supporting fibers, bonding fibers, wave-transparent fibers, and sound-absorbing particles are mixed to obtain a porous sound-absorbing composite material. Then, the fiber layer is folded or otherwise made into a packaging bag, and the porous sound-absorbing composite material is filled into the packaging bag made of the fiber layer using a small filling machine for sealing. Heat treatment is performed under negative pressure to bond the fiber layer with the porous sound-absorbing composite material, resulting in an acoustic composite material block with a porous sound-absorbing structure encapsulated by a fiber layer.

[0050] This disclosure also provides an electronic device having a speaker cavity filled with an acoustic composite material block according to this disclosure. The electronic device may include at least one of a smartphone, tablet, laptop, and smartwatch.

[0051] To further illustrate the acoustic composite material block of this disclosure, this disclosure also provides a method for manufacturing the above-mentioned acoustic composite material block with fiber layers.

[0052] Example

[0053] This disclosure provides an acoustic composite material block, the preparation method of which includes the following steps:

[0054] The first step involves weighing out 0.45g of acrylic pulp fiber and polyvinyl alcohol fiber, 0.49g of basalt fiber and volcanic rock fiber, 0.60g of PET precipitated fiber and glass fiber cotton fiber, and 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzodioxazole) fiber). Then, weigh out 15.1g of ZSM-5 molecular sieve sound-absorbing particles. The average particle size of the ZSM-5 molecular sieve is 200μm, including nano-sized pores with a pore size of 2nm, micro-sized pores with a pore size of 10μm, and millimeter-sized pores with a pore size of 0.09mm. The particles are then mechanically stirred until homogeneous to obtain a porous sound-absorbing composite material.

[0055] The second step involves weighing 0.48g of acrylic pulp fiber and polyvinyl alcohol fiber, 0.63g of PET precipitated fiber and glass fiber cotton fiber, 1.80g of aramid fiber and PBO fiber (poly(p-phenylene benzodioxazole) fiber), and 1.2g of polyphenylene sulfide fiber. All the weighed fibers are transferred to a carding machine, water is injected, and the fibers are carded and dispersed for 20 minutes. The fibers are then wet-formed to obtain a fiber layer.

[0056] The third step involves the mold fixture, with a thickness of 1.2 mm and a circular diameter of 1.2 cm. 0.048 g of the porous sound-absorbing composite material is weighed into a folded fiber-layered packaging bag and then transferred to the mold fixture. This mold fixture has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5 MPa to -0.01 MPa, the heat treatment temperature is 90℃, and the treatment time is 30 seconds. After the mold fixture is opened, the acoustic composite material block automatically detaches from the mold cavity, resulting in a porous sound-absorbing structure wrapped with a fiber layer. After heat treatment, the nano-scale, micro-scale, and millimeter-scale pores of the ZSM-5 molecular sieve form the first-level channels. The second-level channels are formed between the fibers and the ZSM-5 molecular sieve, as well as between the particles of the ZSM-5 molecular sieve. Figure 2 A scanning electron microscope image of an acoustic composite material block according to an embodiment of the present disclosure is shown.

[0057] Comparative Example

[0058] This disclosure provides a comparative example of an acoustic composite material block, the preparation method of which includes the following steps:

[0059] The first step involves weighing out 0.45g of acrylic pulp fiber and polyvinyl alcohol fiber, 0.49g of basalt fiber and volcanic rock fiber, 0.60g of PET precipitated fiber and glass fiber cotton fiber, and 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzodioxazole) fiber). Then, weigh out 15.1g of ZSM-5 molecular sieve sound-absorbing particles. The average particle size of the ZSM-5 molecular sieve is 200μm, including nano-sized pores with a pore size of 2nm, micro-sized pores with a pore size of 10μm, and millimeter-sized pores with a pore size of 0.09mm. The particles are then mechanically stirred until homogeneous to obtain a porous sound-absorbing composite material.

[0060] The second step involves the mold fixture, with a thickness of 1.2 mm and a circular diameter of 1.2 cm. 0.048 g of the porous sound-absorbing composite material is weighed into a folded fiber-layered packaging bag and then transferred to the mold fixture. This mold fixture has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5 MPa to -0.01 MPa, the heat treatment temperature is 90℃, and the treatment time is 30 seconds. After the mold fixture is opened, the acoustic composite material block can automatically detach from the mold cavity, resulting in a porous sound-absorbing structure. After heat treatment, the nano-scale, micro-scale, and millimeter-scale pores of the ZSM-5 molecular sieve form the first-level channels. The second-level channels are formed between the fibers and the ZSM-5 molecular sieve, as well as between the particles of the ZSM-5 molecular sieve. Figure 3 A scanning electron microscope image of an acoustic composite material block, which is a comparative example of this disclosure, is shown.

[0061] In this disclosure, the acoustic reinforcement material blocks prepared in the embodiments and comparative examples were tested according to part 7.4 of the group standard "Porous Sound Absorbing Particles for Miniature Loudspeakers" (standard number: T / CECA 78-2022) to determine the resonant frequency shift value Δf0 of the sheet-like acoustic composite material blocks.

[0062] Then calculate the acoustic efficiency per unit mass of sheet acoustic reinforcement material using the formula shown below:

[0063] Acoustic efficiency = Δf0 / (dry mass of the ball), unit: Hz / mg

[0064] Finally, the sample performance of this example is expressed as a percentage of the acoustic efficiency of the example or comparative sample:

[0065] Sample acoustic efficiency percentage = (sample acoustic efficiency / acoustic efficiency of the dry mass of the spheres)%. The results are shown in Table 1.

[0066] Table 1: Performance Test Data of Acoustic Composite Material Blocks

[0067]

[0068] Data from the examples and comparative examples, and Figure 2 and Figure 3 As can be seen, the acoustic composite material block of this embodiment uses functional fibers with different structures (different diameters and aspect ratios), and the mixing and bonding of fibers with porous sound-absorbing particles and the density of the outer fiber layer constitute a rich porous network structure. This makes it very easy for the drawn-in air to be drawn into the interior of the sound-absorbing composite material block, where it is repeatedly collided, reflected, and rubbed by the pores, achieving the effect of virtually enlarging the cavity. The acoustic composite material block of the comparative example does not use a fiber layer for coating. The porous sound-absorbing particles and fibers are directly dry-mixed and then molded and heat-treated. Because there is no buffering effect of the functional fiber layer, the porous sound-absorbing particles inside are flattened and crushed, and relative position slippage occurs. This causes the porous sound-absorbing particles to easily accumulate together, and the fibers are squeezed together, resulting in uneven pore size distribution. In addition, the crushing of porous particles causes the failure of nanoscale pores and the destruction of other pore sizes, resulting in a decrease in its sound absorption performance. Furthermore, the powder shedding leads to poor acoustic performance durability.

[0069] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0070] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0071] Additionally, as used herein, the “or” used in a list of items beginning with “at least one” indicates a separate list, such that a list of, for example, “at least one of A, B, or C” means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word “exemplary” does not imply that the described example is preferred or better than other examples.

[0072] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0073] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0074] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0075] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. An acoustic composite material block, characterized in that, It includes a porous sound-absorbing structure and a fiber layer wrapped around the outer surface of the porous sound-absorbing structure. The fiber layer has a three-dimensional mesh structure. The porous sound-absorbing structure has a first-level channel and a second-level channel. The first-level channel and the second-level channel are connected. The first-level channel and the second-level channel are also connected to the mesh of the three-dimensional mesh structure.

2. The acoustic composite material block according to claim 1, characterized in that, In the porous sound-absorbing structure, the first-level pores account for 8% to 10% of the volume of the porous sound-absorbing structure, and the second-level pores account for 15% to 20% of the volume of the porous sound-absorbing structure.

3. The acoustic composite material block according to claim 1, characterized in that, The porous sound-absorbing structure includes fibers and sound-absorbing particles bonded together, with first-order channels formed between the fibers and the sound-absorbing particles, as well as between the particles themselves.

4. The acoustic composite material block according to claim 3, characterized in that, The first-level channel includes a first micrometer-level channel and a first millimeter-level channel. The diameter of the first micrometer-level channel is 0.08μm to 30μm, and the diameter of the first millimeter-level channel is 0.08mm to 2mm.

5. The acoustic composite material block according to claim 4, characterized in that, In the first-level channel, the volume ratio of the first micrometer-level channel to the first millimeter-level channel is (36-40):(58-63).

6. The acoustic composite material block according to claim 3, characterized in that, The sound-absorbing particles comprise a porous material, wherein the pores in the porous material form secondary channels.

7. The acoustic composite material block according to claim 6, characterized in that, The second-level channels include nanoscale channels, second micrometer-level channels, and second millimeter-level channels. The pore size of the nanoscale channels is 0.2 nm to 100 nm, the pore size of the second micrometer-level channels is 0.1 μm to 80 μm, and the pore size of the second millimeter-level channels is 0.08 mm to 0.2 mm.

8. The acoustic composite material block according to claim 7, characterized in that, In the second-level channel, the volume ratio of the nano-scale channel, the second micrometer-scale channel, and the second millimeter-scale channel is (18-30):(25-33):(37-57).

9. The acoustic composite material block according to any one of claims 1 to 7, characterized in that, The thickness of the fiber layer is 0.1 mm to 0.2 mm.

10. An electronic device, characterized in that, The electronic device has a speaker cavity filled with an acoustic composite material block according to any one of claims 1 to 9.

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