Acoustic material block, preparation method and electronic equipment

Abstract

The invention relates to the technical field of acoustic materials, and particularly provides an acoustic material block, a preparation method and electronic equipment. The acoustic material block comprises a first reticular fiber layer, a second reticular fiber layer and a sound absorption layer bonded between the first reticular fiber layer and the second reticular fiber layer, the sound absorption layer comprises a porous grid structure, and the porous grid structure comprises loose fiber cotton, a porous material and an inorganic material which are uniformly interwoven together. The preparation method is used for preparing the acoustic material block, and the electronic equipment comprises the acoustic material block. According to the acoustic material block, the preparation method and the electronic equipment provided by the invention, the possibility of powder falling of the material of the sound absorption layer is reduced, and the stability of the acoustic material in the use process is ensured.

Description

Technical Field

[0001] The present disclosure relates to the technical field of acoustic materials, and in particular to an acoustic material block, a preparation method thereof, and an electronic device. Background Art

[0002] With the development of multimedia devices, micro speakers are widely used, but due to space limitations, it is difficult to improve their performance in the low-frequency range. Currently, the low-frequency performance of micro speakers is mainly improved by filling the speaker cavity with sound-absorbing materials.

[0003] However, the sound-absorbing materials in the related technology are not strong enough, and there is a great risk of falling off and powdering during long-term use. They can easily contaminate the speaker cavity and affect the normal sound effect of the speaker. They may also cause damage to other parts of the speaker and reduce its service life. Summary of the invention

[0004] The present disclosure is proposed in view of the above problems. The present disclosure provides an acoustic material block and a preparation method thereof and an electronic device, which reduce the possibility of the material of the sound absorbing layer falling off and ensure the stability of the acoustic material during use.

[0005] According to a first aspect of the present disclosure, there is provided an acoustic material block, comprising:

[0006] a first mesh fiber layer and a second mesh fiber layer;

[0007] The sound absorbing layer is bonded between the first mesh fiber layer and the second mesh fiber layer, and the sound absorbing layer has a porous grid structure, and the porous grid structure includes fiber loose cotton, porous materials and inorganic materials uniformly interwoven together.

[0008] According to a second aspect of the present disclosure, there is provided a method for preparing an acoustic material block, comprising: providing a first mesh fiber layer and a second mesh fiber layer;

[0009] Mixing fiber loose cotton, porous material, inorganic material, resin and water to obtain sound absorbing layer slurry;

[0010] The sound absorbing layer slurry is formed between the first mesh fiber layer and the second mesh fiber layer to obtain an acoustic material block.

[0011] According to a third aspect of the present disclosure, an electronic device is provided, comprising the acoustic material block according to the first aspect of the present disclosure.

[0012] In one or more technical solutions provided in the embodiments of the present disclosure, the acoustic material block includes a first mesh fiber layer, a second mesh fiber layer, and a sound-absorbing layer bonded between the first mesh fiber layer and the second mesh fiber layer, which is equivalent to using the mesh fiber layer to cover the upper and lower surfaces of the sound-absorbing layer. Therefore, the possibility of clogging the vents and other components due to the powdering of the sound-absorbing layer is reduced, and the stability of the acoustic material during use is ensured. At the same time, the upper and lower covering structures can also improve the mechanical strength of the acoustic material block, provide external support and protection for the sound-absorbing layer, prevent the sound-absorbing layer from being deformed or damaged by external forces during use, and extend its service life.

[0013] On this basis, the sound-absorbing layer of the embodiment of the present disclosure includes a porous grid structure, and the porous grid structure includes fiber loose cotton, porous materials and inorganic materials that are uniformly interwoven together. Therefore, three different types of materials are uniformly interwoven together to form a porous grid structure, so that the materials support and restrain each other. At the same time, since the fiber loose cotton has a strong resistance to carbonization temperature, it can be used as a reinforcement for the sound-absorbing layer to a certain extent, playing a role similar to a "skeleton", connecting the porous material and the inorganic material, improving the strength of the sound-absorbing layer, and further avoiding the sound-absorbing layer from falling powder. Moreover, compared with the sound-absorbing layer composed of a single material, the sound-absorbing layer of this porous grid structure has better structural stability. During long-term use, it can resist the influence of external force impact, vibration and other factors, maintain the stability of its sound absorption performance, and reduce the possibility of a decrease in the sound absorption effect due to structural deformation or damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0015] Figure 1 A schematic diagram of the structure of an acoustic material block provided in an embodiment of the present disclosure;

[0016] Figure 2 The present invention is a flow chart of the preparation of the acoustic material block according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present disclosure more obvious, the exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described here.

[0018] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0020] In the description of the present disclosure, it is necessary to understand that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present disclosure.

[0021] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0022] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present disclosure should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0023] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0024] Mobile phones, tablets, laptops and other electronic products are becoming thinner and lighter, so the resonant cavity of the speaker system components they use is also getting smaller. As we all know, the smaller and smaller resonant cavity of the speaker leads to higher resonant frequency and lower low-frequency sound pressure sensitivity, while consumers have higher and higher requirements for the audio quality of electronic products such as mobile phones, tablets, and laptops. In order to resolve the contradiction between the two, acoustic enhancement materials came into being. It is a conventional method to improve the audio quality of small-cavity speakers to prepare porous powder materials that can efficiently adsorb and release air molecules into sound-absorbing particles with an average particle size of 200μm to 800μm through molding technology, and fill them in the speaker cavity. However, this method also has certain shortcomings.

[0025] For example: First, the existing technology usually fills the sound-absorbing particles into the speaker cavity by filling, but the filling process is relatively difficult. In particular, the resonance cavity space of some miniature speakers is very small, and its space height is in the range of hundreds of microns. It is almost impossible to quantitatively fill sound-absorbing particles in such a narrow resonance cavity. However, the narrow resonance cavity often has the greatest impact on low frequencies, and it is also the structure that most needs to be filled with sound-absorbing materials. Secondly, during the operation of the speaker, traditional sound-absorbing particles vibrate at a high frequency in the cavity and collide with the inner wall of the cavity, causing the sound-absorbing particles to break and break into powder, damaging the speaker unit. Moreover, in the current filling process, the sound-absorbing particles can only fill about 80% of the volume of the back cavity of the speaker module, and the back cavity space cannot be fully utilized.

[0026] Therefore, the use of porous powder materials that can efficiently absorb and release air molecules to prepare acoustic materials has gradually emerged to improve the audio quality of small cavity speakers. However, there is still a high risk of shedding and powdering during long-term use, which can easily contaminate the speaker cavity and affect the normal sound effect of the speaker. It may also damage other parts of the speaker and reduce its service life.

[0027] In view of the above problems, the embodiments of the present disclosure provide an acoustic material block and a preparation method thereof and an electronic device, which reduce the possibility of the material of the sound absorbing layer falling off and ensure the stability of the acoustic material during use. The electronic device may include at least one of a smart phone, a tablet computer, a laptop computer and a smart watch.

[0028] Figure 1 FIG. 2 shows a schematic diagram of the structure of an acoustic material block provided by an embodiment of the present disclosure. Figure 1 As shown, the acoustic material block according to the embodiment of the present disclosure includes a first mesh fiber layer 110 , a second mesh fiber layer 120 , and a sound absorbing layer 130 bonded between the first mesh fiber layer 110 and the second mesh fiber layer 120 .

[0029] In practical applications, the embodiment of the present disclosure is equivalent to using a mesh fiber layer to cover the upper and lower surfaces of the sound-absorbing layer. Therefore, the possibility of the sound-absorbing layer material falling off and blocking the vents and other components is reduced, ensuring the stability of the acoustic material during use. At the same time, the upper and lower covering structures can also improve the mechanical strength of the acoustic material block, provide external support and protection for the sound-absorbing layer, prevent the sound-absorbing layer from being deformed or damaged by external forces during use, and extend its service life.

[0030] Exemplarily, the sound absorbing layer 130 has a porous grid structure, and the porous grid structure includes fiber loose cotton, porous materials and inorganic materials uniformly interwoven together.

[0031] Therefore, the three different types of materials are evenly interwoven to form a porous grid structure, so that the materials support and restrain each other. At the same time, because the fiber loose cotton itself has a strong resistance to carbonization temperature, it can be used as a reinforcement of the sound-absorbing layer to a certain extent, playing a role similar to a "skeleton", connecting the porous material and the inorganic material, improving the strength of the sound-absorbing layer, and further avoiding the sound-absorbing layer from falling powder. Moreover, compared with the sound-absorbing layer composed of a single material, this sound-absorbing layer with a porous grid structure has better structural stability. During long-term use, it can resist the influence of external impact, vibration and other factors, maintain the stability of its sound-absorbing performance, and reduce the possibility of a decrease in sound absorption effect due to structural deformation or damage.

[0032] On this basis, inorganic materials can be used as binders to better bond the fiber loose cotton and porous materials together, so that the sound-absorbing layer is not easy to fall off. At the same time, as part of the porous network structure, inorganic materials can increase the hardness of the sound-absorbing layer, making it more solid and less likely to deform.

[0033] In one achievable manner, the fiber wool of the embodiment of the present disclosure may include at least one of silica, alumina and zirconium oxide. For example, the fiber wool may be a mixture of silica and alumina, or a mixture of silica, alumina and zirconium oxide. The components such as silica and alumina in the fiber wool have a porous structure or special physical properties, which can effectively absorb the energy of sound waves. The porous structure allows the sound waves to be reflected and rubbed multiple times inside the fiber wool, thereby converting the sound energy into heat energy to achieve a sound absorption effect.

[0034] When the fiber bulk includes silica and alumina, the mass ratio of silica to alumina is 1:(1.1-1.9), and the total mass of alumina and silica accounts for more than 98% of the mass of the fiber bulk. Therefore, the fiber bulk with a high silica-alumina ratio has a high hydrophobicity, which can prevent moisture from accumulating in the sound-absorbing material to a certain extent, and avoid the sound absorption performance being affected by moisture. At the same time, high hydrophobicity can also improve the water resistance and durability of the sound-absorbing material, so that it can maintain good performance even in a humid environment.

[0035] The softening point of the fiber wool of the embodiment of the present disclosure is greater than 800° C. Therefore, the interwoven fiber wool, porous material and inorganic material can maintain a stable structure in a high temperature environment and are not easily softened and deformed, thereby enhancing the stability of the sound absorbing layer and extending the service life of the acoustic material block.

[0036] In one feasible manner, the diameter of the above-mentioned fiber loose cotton is 0.1μm to 3μm. Therefore, when such fiber loose cotton with a smaller diameter is interwoven with porous materials and inorganic materials, it will not cause blockage to the pores of porous materials and inorganic materials. While ensuring that it can enter the pores to enhance the sound absorption effect, it can also maintain the connectivity of the material pores. In this way, air and other media can still flow in the pores, so that sound waves can be smoothly propagated and absorbed inside the material, and the air permeability and sound absorption efficiency of the sound-absorbing material will not be affected by pore blockage. At the same time, a smaller diameter can increase the specific surface area of ​​the sound-absorbing layer, so that when air and other media pass through the sound-absorbing layer, the contact area with the sound-absorbing layer is larger, and it is easier to propagate and absorb inside the sound-absorbing layer, thereby improving the low-frequency acoustic performance.

[0037] In one example, the porous material of the embodiment of the present disclosure includes at least one of zeolite molecular sieve, activated silica, activated carbon, calcium carbonate, calcium silicate, aluminum oxide, hydrogel, and aerogel. It should be understood that the porous material can be in the form of powder.

[0038] For the above-mentioned zeolite molecular sieve, it can include at least one of MFI structure molecular sieve, FER structure molecular sieve, CHA structure molecular sieve, MEL structure molecular sieve, TON structure molecular sieve and MTT structure molecular sieve. It should be understood that no matter the zeolite molecular sieve is MFI structure molecular sieve, FER structure molecular sieve, CHA structure molecular sieve, MEL structure molecular sieve, TON structure molecular sieve or MTT structure molecular sieve, the zeolite molecular sieve can include micropores with a pore size of 0.3nm to 0.7nm and mesopores with a pore size of 10nm to 30nm.

[0039] The dual-aperture structure of micropores and mesopores can adjust the air flow inside the sound-absorbing layer. In the sound absorption process, the flow of air has an important influence on the propagation and absorption of sound waves. The combination of micropores and mesopores is like a complex pipe network, in which air can flow along different paths, making the propagation path of sound waves inside the sound-absorbing material more diverse, increasing the chance of sound waves contacting the sound-absorbing material, and thus improving the sound absorption efficiency.

[0040] The MFI structure molecular sieve may include a ZSM-5 molecular sieve.

[0041] In one example, the average particle size of the porous material is 0.1 μm to 10 μm. It can be seen that if the particle size of the porous material is set within this range, the porous material can have a higher specific surface area, and more surfaces can provide more adsorption sites and energy dissipation areas, thereby enhancing the sound absorption performance.

[0042] In an optional manner, the inorganic material of the embodiment of the present disclosure includes a first inorganic material and a second inorganic material, and the melting point of the first inorganic material is lower than the melting point of the second inorganic material. Therefore, in the process of sintering and the like, when the temperature rises to near the melting point of the first inorganic material, the first inorganic material will melt first, so that the first inorganic material can better fill the gap between the fiber loose cotton and the porous material in the sound absorbing layer, playing a role of bonding and fixing. The second inorganic material, due to its higher melting point, can still maintain its solid form at this temperature, providing structural support for the sound absorbing layer and ensuring that the entire material will not be excessively deformed during processing.

[0043] On this basis, the second inorganic material has a higher melting point, which enables it to maintain good mechanical properties at both room temperature and higher temperature. As the main supporting structure of the sound-absorbing layer, it can effectively improve the compressive strength and flexural strength of the sound-absorbing layer. The bonding effect of the first inorganic material during the processing can further enhance the bonding force between the materials, so that when the sound-absorbing layer is subjected to external force, the internal materials are not easy to separate, thereby improving the overall mechanical strength of the sound-absorbing layer and extending its service life.

[0044] Exemplarily, the first inorganic material includes at least one of aluminum hydroxide, glass material, silica sol, alumina sol, and water glass, and the second inorganic material includes at least one of silicon micropowder, kaolin, and attapulgite.

[0045] In one achievable manner, the thickness of the acoustic material block of the embodiment of the present disclosure is 0.5 mm to 2 mm, and the specific surface area of ​​the acoustic material block is greater than 300 m 2 Therefore, a larger specific surface area can make the acoustic material block have a larger contact area with the air, thereby providing more opportunities for the reflection and scattering of sound waves, so that the acoustic material block can absorb the sound wave energy more effectively.

[0046] In an achievable manner, the surface density of the first mesh fiber layer and the second mesh fiber layer of the embodiment of the present disclosure is 4 g / m 2 ~12g / m 2 , thickness of 10μm to 100μm, and tensile strength greater than 3kN / m. Among them, the surface density affects the density of the fiber layer. When the surface density is within this range, the fiber layer will not be too sparse to allow sound waves to easily penetrate, nor too dense to prevent sound waves from entering the sound-absorbing layer. Moreover, the mesh fiber layer with a tensile strength greater than 3kN / m provides good mechanical protection for the sound-absorbing layer, ensuring that the sound-absorbing layer remains intact in complex use environments, thereby maintaining its sound-absorbing performance.

[0047] The embodiment of the present disclosure provides a method for preparing an acoustic material block, which can be used to prepare the acoustic material block of the embodiment of the present disclosure. Figure 2 The preparation flow chart of the acoustic material block of the embodiment of the present disclosure is shown as follows: Figure 2 As shown, the method for preparing the acoustic material block of the embodiment of the present disclosure includes:

[0048] Step 201: providing a first mesh fiber layer and a second mesh fiber layer.

[0049] For example, first, the fiber loose cotton, the bonding fiber and the wave-transmitting fiber can be dispersed to obtain a fiber dispersion liquid. Then, the fiber dispersion liquid is wet-formed into a first mesh fiber layer and a second mesh fiber layer. It should be understood that the first mesh fiber layer and the second mesh fiber layer are the same.

[0050] For example, loose fiber, bonding fiber and wave-transmitting fiber can be dispersed in water with defoamer and hydrophilic agent, and then wet-formed to obtain a quantitative 10g / m 2The fiber layer is placed in an oven at 100°C for drying until it is completely dried to obtain a mesh fiber layer. The above operation is repeated to prepare multiple mesh fiber layers, so that two of the mesh fiber layers can be selected as the first mesh fiber layer and the second mesh fiber layer. It should be understood that the first mesh fiber layer and the second mesh fiber layer can be at least one of a fiber web, a fiber paper and a fiber felt.

[0051] It is understandable that the above-mentioned fiber loose cotton is the same as the fiber loose cotton in the sound absorbing layer, and will not be described in detail here.

[0052] As for the bonding fiber, it can include at least one of polyvinyl alcohol fiber, polyethylene fiber, polyethylene fiber pulp, polypropylene fiber, acrylic fiber pulp, polyester fiber and polyester fiber pulp. Among them, the polyvinyl alcohol fiber includes water-soluble polyvinyl alcohol fiber and water-insoluble polyvinyl alcohol fiber. The polyester fiber includes at least one of a skin-core structure polyester fiber, a hollow structure polyester fiber, a core-shell structure polyester fiber and a bonding type polyester fiber.

[0053] The wave-transmitting fiber may include at least one of poly(p-phenylene benzobisoxazole) fiber, quartz fiber, aramid 1313, silica fiber, aramid 1414, aramid pulp, aramid fiber, polyimide fiber, and boron nitride wave-transmitting fiber. It should be understood that the wave-transmitting fiber of the embodiment of the present disclosure is light in weight, can transmit electromagnetic waves, and hardly changes the properties of the electromagnetic waves.

[0054] Step 202: Mix fiber loose cotton, porous material, inorganic material, resin and water to obtain sound absorbing layer slurry.

[0055] Exemplarily, the resin is dispersed in water, stirred evenly, and then the porous material, the first inorganic material and the second inorganic material are slowly added, stirred evenly, and then fiber loose cotton is added, stirred and dispersed for 30 minutes to obtain a sound absorbing layer slurry.

[0056] In one example, the preparation process of the above-mentioned fiber loose cotton is: one or more of aluminum oxide, silicon dioxide, zirconium oxide, etc. are mixed, and then beaten so that one fiber loose cotton can be branched or cut into multiple fiber loose cottons. Among them, the beating degree is 14° to 51°. When the beating degree is within a suitable range, the fiber can play a reinforcing role without clogging the pores. For example, fibers with a moderate beating degree can support the structure of the sound-absorbing layer like a bracket, and at the same time will not hinder the propagation and absorption of sound waves in the pores.

[0057] The above-mentioned resin may include at least one of acrylate resin, epoxy resin and polyurethane resin, or may include at least one of water-based resin, solvent-based resin and UV light-curable resin.

[0058] In one achievable method, the mass ratio of the above-mentioned fiber bulk cotton, porous material, inorganic material, resin and water is (3-7): (42-55): (6-10): (18-26): (12-25). By balancing the functions of each material through a reasonable ratio, the sound-absorbing layer can have advantages in many aspects such as good sound absorption performance, structural stability and processing convenience.

[0059] Step 203: forming a sound absorbing layer slurry between the first mesh fiber layer and the second mesh fiber layer to obtain an acoustic material block.

[0060] For example, the sound absorbing layer slurry may be formed between the first mesh fiber layer and the second mesh fiber layer to obtain a prefabricated acoustic material block, and then the prefabricated acoustic material block may be dried, carbonized and sintered to obtain the acoustic material block.

[0061] For example, the sound-absorbing layer slurry can be applied to the first mesh fiber layer by knife coating, and then covered with the second mesh fiber layer, placed in a mold, fully dried, and demolded to obtain a prefabricated acoustic material block, the drying temperature is 90°C to 200°C, and the drying time is 10min to 30min. Then, the prefabricated acoustic material block is transferred to a muffle furnace for carbonization and sintering, so that the sound-absorbing layer slurry is formed between the first mesh fiber layer and the second mesh fiber layer, and an acoustic material block is obtained, the carbonization and sintering temperature is 400°C to 600°C, and the carbonization and sintering time is 15min to 60min.

[0062] The bonding fibers contained in the first mesh fiber layer and the second mesh fiber layer can play a role in bonding into a net / paper / felt during the fiber forming process, and will melt, carbonize and decompose during the subsequent carbonization and sintering of the acoustic material block. The fiber loose cotton contained in the first mesh fiber layer and the second mesh fiber layer has a small diameter, and the net / paper / felt formed is relatively dense, which can ensure that the coated sound-absorbing layer slurry does not leak. The wave-transmitting fibers in the first mesh fiber layer and the second mesh fiber layer are materials that can transmit electromagnetic waves and hardly change the properties (including energy) of the electromagnetic waves, so that the generated acoustic signals are well adsorbed and desorbed by the sound-absorbing material block, which has the effect of enhancing the low-frequency acoustic performance.

[0063] On this basis, resin is added to the above-mentioned sound-absorbing layer slurry. When the sound-absorbing layer slurry is coated on the first mesh fiber layer and covered with the second mesh fiber layer and dried, it can play a bonding role and tightly bond the sound-absorbing layer slurry and the two mesh fiber layers. Moreover, after carbonization and sintering, the resin binder is carbonized and decomposed, and the through holes left behind can supplement the specific surface area of ​​the sound-absorbing material block. During the carbonization and decomposition process, many tiny channels and pores are formed in the space originally occupied by the resin. The through holes increase the contact area between the material and the outside world, providing more places for the absorption of sound waves. The through holes can also supplement the opening of closed pores formed by porous materials, so that air can flow better inside the material. In this way, when sound waves cause the vibration of air molecules, the air molecules can diffuse inside the material through these connected pores, increasing the contact area of ​​air adsorption and improving the low-frequency acoustic performance.

[0064] In addition, inorganic materials are added to the above-mentioned sound-absorbing layer slurry. The inorganic materials can be used as binders to better bond the fiber loose cotton and the porous material together, and the sound-absorbing layer is not easy to fall off and powder. At the same time, as part of the porous network structure, the inorganic material can increase the hardness of the sound-absorbing layer, making the sound-absorbing layer more solid and not easy to deform. Moreover, in the sintering and other process links, when the temperature of the first inorganic material and the second inorganic material in the inorganic material rises to near the melting point of the first inorganic material, the first inorganic material will melt first, so that the first inorganic material can better fill the gap between the fiber loose cotton and the porous material in the sound-absorbing layer, playing a role of bonding and fixing. Due to its high melting point, the second inorganic material can still maintain its solid form at this temperature, providing structural support for the sound-absorbing layer and ensuring that the entire material will not be excessively deformed during processing.

[0065] The present disclosure also provides an electronic device, which includes the acoustic material block of the present disclosure. The electronic device may include at least one of a smart phone, a tablet computer, a laptop computer, and a smart watch.

[0066] The acoustic material block, preparation method and electronic device of the disclosed embodiment have simple processes, and the acoustic material block can be directly cut and packaged into a micro speaker or directly prepared into a suitable size and packaged into a micro speaker without being prepared into particles for canning. At the same time, the upper and lower surfaces of the sound absorbing layer are coated with a mesh fiber layer, which reduces the possibility of the material of the sound absorbing layer falling off, and ensures the stability of the acoustic material during use.

[0067] In order to verify the effect of the acoustic material block provided by the embodiment of the present disclosure, the embodiment of the present disclosure is demonstrated by comparing the embodiment with a comparative example.

[0068] Embodiment 1

[0069] The first embodiment of the present disclosure provides an acoustic material block, and the preparation method thereof comprises the following steps:

[0070] The first step is to prepare the first mesh fiber layer and the second mesh fiber layer: first, 240g of glass fiber loose wool with a beating degree of 14°, 160g of PVA fiber, and 1kg of poly(p-phenylene benzobisoxazole) fiber are dispersed in water with a defoamer and a hydrophilic agent added thereto for dispersion, and then wet-formed to obtain a quantitative 10g / m 2 The fiber felt is placed in an oven at 100°C for drying until it is completely dry to obtain a first mesh fiber layer. The steps are then repeated to obtain a second mesh fiber layer.

[0071] The second step is to prepare the slurry for the sound-absorbing layer: take 290g of water-dispersed 430g of water-based polyurethane resin, stir evenly, then slowly add 1kg of MFI zeolite molecular sieve with a particle size of 200nm~300nm, 60g of low-melting point glass ceramic powder with a particle size of 3μm~9μm and 80g of silicon micropowder with a particle size of 600nm~900nm, stir evenly, then add loose cotton with a beating degree of 14° and resistance to 1200℃, stir and disperse for 30 minutes to obtain the slurry for the sound-absorbing layer.

[0072] The third step is to prepare an acoustic material block: the sound-absorbing layer slurry prepared in the second step is applied to the first mesh fiber layer prepared in the first step by blade coating, and then covered with the second mesh fiber layer, placed in a mold, dried at 180°C for 30 minutes to make it fully dry, then demolded, transferred to a muffle furnace, and carbonized and sintered at 400°C for 20 minutes to obtain a sound-absorbing material block.

[0073] Embodiment 2

[0074] The second embodiment of the present disclosure provides an acoustic material block, and the preparation method thereof comprises the following steps:

[0075] The first step is to prepare the first mesh fiber layer and the second mesh fiber layer: first, 310g of glass fiber loose wool with a beating degree of 23°, 230g of PVA fiber, 500g of poly(p-phenylene benzobisoxazole) fiber, and 500g of basalt fiber are dispersed in water with a defoamer and a hydrophilic agent added thereto for dispersion, and then wet-formed to obtain a 14g / m 2 The fiber felt is placed in an oven at 100°C for drying until it is completely dry to obtain a first mesh fiber layer. The steps are then repeated to obtain a second mesh fiber layer.

[0076] The second step is to prepare the slurry for the sound-absorbing layer: take 450g of water-dispersed 430g of an aqueous polyurethane resin with a solid content of 29%, stir evenly, then slowly add 1kg of an MFI zeolite molecular sieve with a particle size of 200nm to 500nm, 120g of a low-melting-point glass ceramic powder with a particle size of 3μm to 9μm and 60g of a silicon micropowder with a particle size of 600nm to 900nm, stir evenly, then add loose cotton with a beating degree of 23° and resistance to 1250°C, stir and disperse for 30 minutes to obtain the slurry for the sound-absorbing layer.

[0077] The third step is to prepare an acoustic material block: the sound-absorbing layer slurry prepared in the second step is applied to the first mesh fiber layer prepared in the first step by scraping, and then covered with the second mesh fiber layer, placed in a mold, dried at 180°C for 30 minutes to make it fully dry, then demolded, transferred to a muffle furnace, and carbonized and sintered at 600°C for 30 minutes to obtain a sound-absorbing material block.

[0078] Embodiment 3

[0079] Embodiment 3 of the present disclosure provides an acoustic material block, and a preparation method thereof comprises the following steps:

[0080] The first step is to prepare the first mesh fiber layer and the second mesh fiber layer: first, 280g of glass fiber loose wool with a beating degree of 18°, 120g of PVA fiber, and 1kg of poly(p-phenylene benzobisoxazole) fiber are dispersed in water with a defoamer and a hydrophilic agent added thereto for dispersion, and then wet-formed to obtain a quantitative 10g / m 2 The fiber felt is placed in an oven at 100°C for drying until it is completely dry to obtain a first mesh fiber layer. The steps are then repeated to obtain a second mesh fiber layer.

[0081] The second step is to prepare the slurry for the sound-absorbing layer: take 290g of water-dispersed 430g of water-based polyurethane resin, stir evenly, then slowly add 1kg of MFI zeolite molecular sieve with a particle size of 200nm~300nm, 60g of low-melting point glass ceramic powder with a particle size of 3μm~5μm and 80g of silicon micropowder with a particle size of 700nm~800nm, stir evenly, then add loose cotton with a beating degree of 18° and resistance to 1200℃, stir and disperse for 30 minutes to obtain the slurry for the sound-absorbing layer.

[0082] The third step is to prepare an acoustic material block: the sound-absorbing layer slurry prepared in the second step is applied to the first mesh fiber layer prepared in the first step by blade coating, and then covered with the second mesh fiber layer, placed in a mold, dried at 150°C for 20 minutes to make it fully dry, then demolded, transferred to a muffle furnace, and carbonized and sintered at 500°C for 18 minutes to obtain a sound-absorbing material block.

[0083] Comparative Example 1

[0084] In the second step of preparing the slurry for the sound-absorbing layer, no fiber loose cotton with a beating degree of 14° and resistance to 1200° C. is added, and the rest is consistent with the preparation method in Example 1.

[0085] Comparative Example 2

[0086] Preparation of acoustic material block: Take 290g water-dispersed 430g water-based polyurethane resin, stir evenly, slowly add 1kg MFI zeolite molecular sieve with a particle size of 200nm-300nm, 60g low melting point glass ceramic powder with a particle size of 3μm-9μm and 80g silicon micropowder with a particle size of 600nm-900nm, stir evenly, then add loose cotton with a beating degree of 14° and resistance to 1200℃, stir and disperse for 30min to obtain sound-absorbing layer slurry. Put the sound-absorbing layer slurry into a mold, dry it at 180℃ for 30min to make it fully dry, then demold it, transfer it to a muffle furnace, and carbonize and sinter it at 400℃ for 20min to obtain a sound-absorbing material block.

[0087] Comparative Example 3

[0088] Comparative Example 3 of the present disclosure provides an acoustic material block, and the preparation method thereof comprises the following steps:

[0089] The first step is to provide two layers of breathable non-woven fabric (purchased from Shanghai Xinqi Material Technology Co., Ltd. filament PP filter non-woven fabric), weight 25g / m 2 , melting range 105℃~120℃, breathable.

[0090] The second step is to prepare the slurry for the sound-absorbing layer: take 290g of water-dispersed 430g of water-based polyurethane resin, stir evenly, then slowly add 1kg of MFI zeolite molecular sieve with a particle size of 200nm~300nm, 60g of low-melting point glass ceramic powder with a particle size of 3μm~9μm and 80g of silicon micropowder with a particle size of 600nm~900nm, stir evenly, then add loose cotton with a beating degree of 14° and resistance to 1200℃, stir and disperse for 30 minutes to obtain the slurry for the sound-absorbing layer.

[0091] The third step is to prepare an acoustic material block: the sound-absorbing layer slurry prepared in the second step is applied to the breathable non-woven fabric provided in the first step by blade coating, and then covered with a layer of breathable non-woven fabric, placed in a mold, dried at 180°C for 30 minutes to make it fully dry, then demolded, transferred to a muffle furnace, and carbonized and sintered at 400°C for 20 minutes to obtain a sound-absorbing material block.

[0092] Comparative Example 4

[0093] Comparative Example 4 of the present disclosure provides an acoustic material block, and the preparation method thereof comprises the following steps:

[0094] The first step is to prepare the first mesh fiber layer and the second mesh fiber layer: first, 240g of glass fiber loose wool with a beating degree of 14°, 160g of PVA fiber, and 1kg of poly(p-phenylene benzobisoxazole) fiber are dispersed in water with a defoamer and a hydrophilic agent added thereto for dispersion, and then wet-formed to obtain a quantitative 10g / m 2 The fiber felt is placed in an oven at 100°C for drying until it is completely dry to obtain a first mesh fiber layer. The steps are then repeated to obtain a second mesh fiber layer.

[0095] The second step is to prepare the slurry for the sound-absorbing layer: take 290g of water-dispersed 430g of water-based polyurethane resin, stir evenly, then slowly add 1kg of MFI zeolite molecular sieve with a particle size of 200nm~300nm, 60g of low-melting point glass ceramic powder with a particle size of 3μm~9μm and 80g of silicon micropowder with a particle size of 600nm~900nm, stir evenly, then add loose cotton with a beating degree of 14° and resistance to 1200℃, stir and disperse for 30 minutes to obtain the slurry for the sound-absorbing layer.

[0096] The third step is to prepare an acoustic material block: the sound-absorbing layer slurry prepared in the second step is applied to the first mesh fiber layer prepared in the first step by blade coating, and then covered with the second mesh fiber layer, placed in a mold, dried at 180° C. for 30 minutes to fully dry it, and then demolded to obtain a sound-absorbing material block.

[0097] The acoustic material blocks prepared in Examples 1 to 2 of the present invention and Comparative Examples 1 to 4 and conventional sound-absorbing particle products in the art were tested for acoustic performance. The specific test method for acoustic performance can refer to the "Measurement of Electrical Impedance" method shown in paragraphs 0049 to 0054 of Chinese Patent CN105049997A. The test conditions of the test tool are 0.2cc rear cavity space and 100% volume filling. The test results are shown in Table 1 below:

[0098] Table 1: Acoustic material block performance test data table

[0099]

[0100] It can be seen from the above table that compared with the acoustic material blocks prepared in Comparative Examples 1 to 4, the acoustic material blocks prepared in the embodiment of the present disclosure do not contain the fiber loose cotton of the embodiment of the present disclosure in Comparative Example 1, do not contain the mesh fiber layer of the embodiment of the present disclosure in Comparative Example 2, do not contain the mesh fiber layer of the embodiment of the present disclosure in Comparative Example 3, which is replaced by a conventional non-woven fabric layer, and do not perform the carbonization sintering step in Comparative Example 4. Finally, the acoustic material block prepared in the embodiment of the present disclosure has a lower resonant frequency, better acoustic efficiency durability, better low-frequency acoustic performance, and no shedding or powdering phenomenon. It can be seen that the acoustic material block in the embodiment of the present disclosure, under the joint action of fiber loose cotton, the first mesh fiber layer, the second mesh fiber layer, and the carbonization sintering process, can make the acoustic material block not only not easy to shed or fall off, but also have better acoustic performance.

[0101] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "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 mean that the example described is preferred or better than other examples.

[0102] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0103] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0104] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present 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 the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0105] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An acoustic material block, characterized in that: include: a first mesh fiber layer and a second mesh fiber layer; The sound absorbing layer is bonded between the first mesh fiber layer and the second mesh fiber layer, wherein the sound absorbing layer comprises a porous grid structure, and the porous grid structure comprises fiber loose cotton, porous materials and inorganic materials uniformly interwoven together.

2. The acoustic material block according to claim 1, characterized in that The fiber bulk includes at least one of silicon dioxide, aluminum oxide and zirconium oxide; When the fiber bulk includes silica and alumina, the mass ratio of the silica to the alumina is 1:(1.1-1.9), the total mass of the alumina and the silica accounts for more than 98% of the mass of the fiber bulk, and the softening point of the fiber bulk is more than 800°C.

3. The acoustic material block according to claim 2, characterized in that The diameter of the fiber loose cotton is 0.1 μm to 3 μm.

4. The acoustic material block according to claim 1, characterized in that The porous material includes at least one of zeolite molecular sieve, activated silicon dioxide, activated carbon, calcium carbonate, calcium silicate, aluminum oxide, hydrogel, and aerogel.

5. The acoustic material block according to claim 1, characterized in that The inorganic material comprises a first inorganic material and a second inorganic material, wherein the melting point of the first inorganic material is lower than the melting point of the second inorganic material; The first inorganic material includes at least one of aluminum hydroxide, glass material, silica sol, alumina sol, and water glass, and the second inorganic material includes at least one of silicon micropowder, kaolin, and attapulgite.

6. The acoustic material block according to any one of claims 1 to 5, characterized in that: The thickness of the acoustic material block is 0.5 mm to 2 mm, and the specific surface area of ​​the acoustic material block is greater than 300 m 2 / g.

7. The acoustic material block according to any one of claims 1 to 5, characterized in that: The surface density of the first mesh fiber layer and the second mesh fiber layer is 4 g / m 2 ~12g / m 2 , thickness is 10μm~100μm, and tensile strength is greater than 3kN / m.

8. A method for preparing an acoustic material block according to any one of claims 1 to 7, characterized in that: include: providing a first mesh fiber layer and a second mesh fiber layer; Mixing fiber loose cotton, porous material, inorganic material, resin and water to obtain sound absorbing layer slurry; The sound absorbing layer slurry is formed between the first mesh fiber layer and the second mesh fiber layer to obtain an acoustic material block.

9. The method for preparing the acoustic material block according to claim 8, characterized in that: The mass ratio of the fiber bulk cotton, porous material, inorganic material, resin and water is (3-7): (42-55): (6-10): (18-26): (12-25).

10. The method for preparing an acoustic material block according to claim 8, characterized in that: The method of providing a first mesh fiber layer and a second mesh fiber layer comprises: Dispersing the fiber loose cotton, the bonding fiber and the wave-transmitting fiber to obtain a fiber dispersion; The fiber dispersion is wet-formed into a first web-like fiber layer and a second web-like fiber layer.

11. The method for preparing an acoustic material block according to claim 10, characterized in that: In the fiber dispersion, the mass ratio of the fiber bulk, the bonding fiber and the wave-transmitting fiber is (12-20): (8-15): (50-65).

12. The method for preparing an acoustic material block according to claim 8, characterized in that: The sound absorbing layer slurry is formed between the first mesh fiber layer and the second mesh fiber layer to obtain an acoustic material block, comprising: forming the sound absorbing layer slurry between the first mesh fiber layer and the second mesh fiber layer to obtain a prefabricated acoustic material block; The prefabricated acoustic material block is dried, carbonized and sintered to obtain an acoustic material block.

13. The method for preparing an acoustic material block according to claim 12, characterized in that: The drying temperature is 90°C to 200°C, and the drying time is 10min to 30min; the carbonization sintering temperature is 400°C to 600°C, and the carbonization sintering time is 15min to 60min.

14. An electronic device, characterized in that: The electronic device comprises the acoustic material block according to any one of claims 1 to 8.

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