Acoustic composite material block, preparation method and electronic equipment

Abstract

The invention relates to the technical field of acoustic materials, and particularly provides an acoustic composite material block, a preparation method and electronic equipment. The preparation method of the acoustic composite material block comprises the following steps: carrying out wet molding on functional fibers to form a functional fiber paper base, wrapping a porous sound-absorbing composite material with the functional fiber paper base to obtain a prefabricated acoustic composite material block, and carrying out heat treatment on the prefabricated acoustic composite material block under a negative pressure condition to obtain the acoustic composite material block. The functional fiber paper base is bonded with the porous sound-absorbing composite material, and the acoustic composite material block is obtained. The acoustic composite material block, the preparation method and the electronic equipment provided by the invention are used for avoiding the possibility of powder falling in the cutting process of the acoustic composite material block.

Description

Technical Field

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

[0002] With the development of multimedia devices, micro speakers have been widely used. However, due to space limitations, the resonance cavity of the speaker is getting smaller and smaller, resulting in higher resonance frequency and lower low-frequency sound pressure sensitivity, making it difficult to improve its 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 size of the sound-absorbing material prepared in the related art is relatively large, and it needs to be cut when filling the speaker cavity. During the cutting process, the particles in the sound-absorbing material are easily chopped into small powders, and there is a problem of the sound-absorbing material falling off or falling off, which affects the acoustic performance. Summary of the invention

[0004] The present disclosure is proposed in view of the above problems. The present disclosure provides an acoustic composite material block and a preparation method and an electronic device, which can prepare the acoustic composite material block into a required size without cutting the acoustic composite material block, thereby avoiding the possibility of powder falling during the cutting process.

[0005] According to one aspect of the present disclosure, there is provided a method for preparing an acoustic composite material block, comprising:

[0006] Wet-forming the functional fibers into a functional fiber paper base;

[0007] Using the functional fiber paper substrate to wrap the porous sound-absorbing composite material to obtain a prefabricated acoustic composite material block;

[0008] The prefabricated acoustic composite material block is heat treated under negative pressure conditions so that the functional fiber paper base is bonded to the porous sound-absorbing composite material to obtain an acoustic composite material block.

[0009] According to a second aspect of the present disclosure, an acoustic composite material block is provided, comprising: the acoustic composite material block comprises a porous sound-absorbing composite material and a functional fiber layer wrapped around the outer surface of the porous sound-absorbing composite material, the porous sound-absorbing composite material is bonded to the functional fiber layer, and the functional fiber layer has a three-dimensional network structure.

[0010] According to a third aspect of the present disclosure, an electronic device is provided, comprising the acoustic composite material block according to the second aspect of the present disclosure.

[0011] In one or more technical solutions provided in the embodiments of the present disclosure, first, the functional fiber is wet-formed into a functional fiber paper base, and the porous sound-absorbing composite material is wrapped with the functional fiber paper base to obtain a prefabricated acoustic composite material block. Then, under negative pressure conditions, the prefabricated acoustic composite material block is heat-treated so that the functional fiber paper base is bonded to the porous sound-absorbing composite material to obtain an acoustic composite material block. Therefore, the functional fiber paper base can provide a protective layer for the porous sound-absorbing composite material to prevent the porous sound-absorbing composite material from being damaged by external physical impact, wear and scratches, thereby extending the service life of the porous sound-absorbing composite material. At the same time, the wrapping of the functional fiber paper base can prevent the porous sound-absorbing composite material from falling off, which helps to maintain the stable sound absorption performance of the acoustic composite material block.

[0012] On this basis, the embodiment of the present disclosure bonds the functional fiber paper base to the porous sound-absorbing composite material through negative pressure heat treatment. In a negative pressure environment, the air is extracted, and the gap between the functional fiber paper base and the porous sound-absorbing composite material is fully reduced. During the heat treatment process, the two can be closely fitted, which promotes the movement and interaction of the functional fibers and the surface molecules of the porous sound-absorbing composite material, so that the two can be better combined at the molecular level to form a stable bond, thereby eliminating the need to use more adhesive, avoiding the blockage of the sound-absorbing particle pores by excessive adhesive, and reducing the loss of acoustic performance.

[0013] In addition, since the embodiment of the present disclosure utilizes a functional fiber paper substrate to wrap a porous sound-absorbing composite material to prepare an acoustic composite material block, the functional fiber paper substrate can be made into a suitable size according to the actual size of the speaker cavity, thereby obtaining an acoustic composite material block of a desired size, without the need to cut the acoustic composite material block, thereby avoiding the problem of powder loss and particle shedding during the cutting process. 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 The present invention is a flow chart of preparing an acoustic composite material block according to an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of the cross-sectional structure of an acoustic composite material block provided in an embodiment of the present disclosure. 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, sound-absorbing particles made of porous powder materials are filled into the rear sound cavity of the speaker module, and the special physical channel structure inside the porous material is used to quickly adsorb and desorb the gas in the rear sound cavity, so as to achieve the effect of virtual enlargement of the resonant space of the rear sound cavity of the speaker, thereby effectively reducing the resonant frequency of the speaker and improving the 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 the sound-absorbing particles are flowable inside the rear sound cavity.

[0025] However, when the speaker is working under large amplitude conditions, the sound-absorbing particles vibrate violently in the rear sound cavity, and the sound-absorbing particles or the sound-absorbing particles and the cavity wall rub and collide violently, causing the sound-absorbing particles to break. The powder generated by the breakage of the sound-absorbing particles enters the interior of the speaker unit and causes pollution, resulting in the failure of its acoustic performance.

[0026] Therefore, the related art solves this technical problem by preparing a sound-absorbing block. For example, the sound-absorbing material particles are bonded together with bonding fibers, a binder or other components to obtain a sound-absorbing block, which is then cut into the required size and filled into the cavity of the speaker. However, when the material block is cut, the particles of the sound-absorbing material are easily chopped into small powders, and there is still the problem of powdering and falling off of the sound-absorbing material, which affects the acoustic performance.

[0027] In view of the above problems, the embodiments of the present disclosure provide an acoustic composite material block, a preparation method and an electronic device, which can prepare the acoustic composite material block into a required size without cutting the acoustic composite material block, thus avoiding the possibility of powder falling during cutting and ensuring 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] The embodiment of the present disclosure provides a method for preparing an acoustic material block, which can be used to prepare the acoustic composite material block of the embodiment of the present disclosure. Figure 1 The preparation flow chart of the acoustic composite material block according to the embodiment of the present disclosure is shown as follows: Figure 1 As shown, the method for preparing the acoustic composite material block of the embodiment of the present disclosure includes:

[0029] Step 101: wet-forming the functional fibers into a functional fiber paper base.

[0030] For example, first, a variety of functional fibers can be transferred to a combing machine, and clean water is injected, and the fibers are combed and dispersed for 20 to 50 minutes to obtain a functional fiber dispersion. Then, the functional fiber paper base is formed by wet papermaking. By first dispersing the functional fibers into a functional fiber dispersion and then papermaking, various functional fibers can be evenly distributed on the obtained functional fiber paper base, making the various properties of the paper base more stable.

[0031] Step 102: Wrap the porous sound-absorbing composite material with a functional fiber paper matrix to obtain a prefabricated acoustic composite material block.

[0032] For example, the above-mentioned functional fiber paper matrix can be used to wrap the porous sound-absorbing composite material, so that the porous sound-absorbing composite material is filled in the functional fiber paper matrix to obtain a prefabricated acoustic composite material block.

[0033] Therefore, the functional fiber paper base can provide a protective layer for the porous sound-absorbing composite material to prevent damage to the porous sound-absorbing composite material caused by external physical impact, wear and scratch, and extend the service life of the porous sound-absorbing composite material. At the same time, the wrapping of the functional fiber paper base can prevent the porous sound-absorbing composite material from falling off, which helps to maintain the stability of the sound absorption performance of the porous sound-absorbing composite material.

[0034] In one example, the embodiment of the present disclosure uses a functional fiber paper substrate to wrap a porous sound-absorbing composite material to obtain a prefabricated acoustic composite material block, which specifically includes: first, making a packaging bag with the functional fiber paper substrate. Second, placing the porous sound-absorbing composite material in the packaging bag, so that the functional fiber paper substrate wraps the porous sound-absorbing composite material to obtain a prefabricated acoustic composite material block.

[0035] In practical applications, the functional fiber paper base can be first folded into a packaging bag by folding or other feasible methods, and then the porous sound-absorbing composite material can be filled into the packaging bag made of the functional fiber paper base by a small filling machine to obtain a prefabricated acoustic composite material block.

[0036] In one example, the embodiment of the present disclosure uses a functional fiber paper base to wrap a porous sound-absorbing composite material. Before obtaining a prefabricated acoustic composite material block, the preparation method also includes: mixing a first supporting fiber, a first bonding fiber, a first wave-transmitting fiber and sound-absorbing particles to obtain a porous sound-absorbing composite material.

[0037] The first supporting fibers may include at least one of glass fiber wool, aramid pulp, polyethylene terephthalate fibrids and poly(p-phenylene benzobisoxazole) fibers.

[0038] The first bonding fiber may include at least one of polyvinyl alcohol fiber, polyethylene fiber, polyethylene fiber pulp, polypropylene fiber, acrylic fiber pulp, polyester fiber and polyester fiber pulp. 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 polyester fiber, a hollow polyester fiber, a core-shell polyester fiber and a bonding polyester fiber.

[0039] The first 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 change the properties of the electromagnetic waves.

[0040] The first supporting fibers mentioned above mainly provide structural support for the sound-absorbing particles, ensuring that the acoustic composite material block has a certain mechanical strength during use, can maintain its shape and integrity, and the pores formed between the first supporting fibers and the porous sound-absorbing material have a positive effect on the absorption and desorption of sound in a narrow cavity and air permeability. The first bonding fibers are responsible for effectively bonding the various components together to form a whole composite material to avoid the separation of components during use. The first wave-transmitting fibers help ensure that sound waves can pass through the material more smoothly, which has an important impact on the performance of the material in an acoustic environment.

[0041] The sound absorbing particles may include at least one of zeolite molecular sieve, activated silicon dioxide, activated carbon, calcium carbonate, calcium silicate, aluminum oxide, hydrogel and aerogel.

[0042] 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.

[0043] 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.

[0044] The MFI structure molecular sieve may include a ZSM-5 molecular sieve.

[0045] 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.

[0046] In one achievable manner, in the porous sound-absorbing composite material of the embodiment of the present disclosure, the mass ratio of the first supporting fiber, the first bonding fiber, the first wave-transmitting fiber and the sound-absorbing particles is (5-50): (5-50): (5-50): (50-95). Among them, the mass ratio of the sum of the mass of the first supporting fiber, the first bonding fiber and the first wave-transmitting fiber to the sound-absorbing particles is (5-50): (50-95). By rationally configuring the mass ratio of each component, the best sound-absorbing effect of the material can be achieved, the structural and performance stability can be ensured, and the needs of different application scenarios can be met.

[0047] Step 103: Under negative pressure conditions, heat-treating the prefabricated acoustic composite material block so that the functional fiber paper base and the porous sound-absorbing composite material are bonded to obtain an acoustic composite material block.

[0048] Exemplarily, first, the prefabricated acoustic composite material block is placed in a tooling that simulates a micro-speaker cavity, and the mold tooling has negative pressure suction and heat treatment molding functions, and the negative pressure range is -0.5MPa to -0.01MPa. Under negative pressure conditions, the prefabricated acoustic composite material block is heat treated at a temperature of 85°C to 135°C and a heat treatment time of 10s to 50s, so that the functional fiber paper base is bonded to the porous sound-absorbing composite material to obtain an acoustic composite material block.

[0049] The disclosed embodiment bonds the functional fiber paper base to the porous sound-absorbing composite material through negative pressure heat treatment. In a negative pressure environment, air is extracted, and the gap between the functional fiber paper base and the porous sound-absorbing composite material is sufficiently reduced. During the heat treatment process, the two can be closely fitted, which promotes the movement and interaction of the functional fiber and the surface molecules of the porous sound-absorbing composite material, so that the two can be better combined at the molecular level to form a stable bond, thereby eliminating the need to use more adhesive, avoiding the blockage of the sound-absorbing particle pores by excessive adhesive, and reducing the loss of acoustic performance.

[0050] On this basis, since the embodiment of the present disclosure utilizes a functional fiber paper substrate to wrap a porous sound-absorbing composite material to prepare an acoustic composite material block, the functional fiber paper substrate can be made into a suitable size according to the actual size of the speaker cavity, thereby obtaining an acoustic composite material block of a desired size, without the need to cut the acoustic composite material block, thereby avoiding the problem of powder loss and particle shedding during the cutting process.

[0051] In one achievable manner, the functional fiber of the embodiment of the present disclosure includes a second bonding fiber, a second supporting fiber, a second wave-transmitting fiber and a heat-shrinkable fiber, wherein the mass ratio of the second bonding fiber, the second supporting fiber, the second wave-transmitting fiber and the heat-shrinkable fiber is (12-18): (8-13): (30-35): (16-25).

[0052] The second bonding fiber may include at least one of polyvinyl alcohol fiber, polyethylene fiber, polyethylene fiber pulp, polypropylene fiber, acrylic fiber pulp, polyester fiber and polyester fiber pulp.

[0053] As for the second supporting fiber, it may include at least one of glass fiber wool, aramid pulp, polyethylene terephthalate fibrid and poly(p-phenylene benzobisoxazole) fiber.

[0054] The second 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.

[0055] As for the heat shrinkable fiber, it may include at least one of polyphenylene sulfide fiber, nylon fiber, polyethylene fiber, polypropylene fiber and polyester fiber.

[0056] Exemplarily, the heat shrinkage rate of the heat shrinkable fiber in the temperature range of 90°C to 180°C is 30% to 50%, the elongation at break is ≥30%, and the breaking strength is ≥2cN / dtex. In this temperature range, the length of the heat shrinkable fiber will be greatly shortened, so that the functional fiber paper base can wrap the porous sound-absorbing material more tightly after being heated, and the functional fiber paper base and the porous sound-absorbing material can be fixed together more tightly. Within the range of elongation at break and breaking strength, when the acoustic composite material block encounters external force, it can withstand a certain tensile external force, has good flexibility and extensibility, and can be stretched to a certain extent without being easily broken.

[0057] In one achievable manner, the surface density of the functional fiber paper base of the embodiment of the present disclosure is 20 m 2 ~200g / m 2 , the tensile strength of the functional fiber paper base is ≥3MPa, and the porosity of the functional fiber paper base is ≥90%. It should be understood that the surface density refers to the mass of paper per unit area, and the porosity refers to the ratio of the pore volume to the total volume in the material.

[0058] The disclosed embodiment controls the surface density to 20m 2 ~200g / m 2 , which can make the paper base have better flexibility and ensure that the functional fiber paper base is thinner, so it can better adapt to smaller speaker cavities. Controlling the tensile strength of the functional fiber paper base to ≥3MPa can ensure that the functional fiber paper base will not break easily during use, thereby maintaining the structural integrity and functionality of the acoustic composite material. Controlling the above porosity to ≥90% can make the pores absorb air and other sound propagation media with a larger surface area, thereby improving the sound absorption effect.

[0059] In an optional manner, the volume density of the acoustic composite material block of the embodiment of the present disclosure is 0.4 g / cm 3 ~0.65g / cm 3 It should be understood that bulk density refers to the mass of a material per unit volume. Within this bulk density range, the acoustic composite material block is neither too loose (bulk density is too low) resulting in a loose structure and difficulty in maintaining stable acoustic performance and physical form, nor too dense (bulk density is too high) resulting in significant hindrance to the propagation and absorption of sound waves therein, affecting the acoustic functions such as sound absorption, thereby improving the acoustic performance.

[0060] The present disclosure also provides an acoustic composite material block. Figure 2 FIG. 2 shows a schematic cross-sectional structure diagram of an acoustic composite material block provided by an embodiment of the present disclosure. Figure 2 As shown, the acoustic composite material block of the embodiment of the present disclosure includes a porous sound-absorbing composite material 210 and a functional fiber layer 220 wrapped on the outer surface of the porous sound-absorbing composite material 210, and the porous sound-absorbing composite material 210 is bonded to the functional fiber layer 220, and the functional fiber layer 220 has a three-dimensional mesh structure. Therefore, the functional fiber paper base can provide a protective layer for the porous sound-absorbing composite material to prevent the porous sound-absorbing composite material from being damaged by external physical impact, wear and scratches, thereby extending the service life of the porous sound-absorbing composite material. At the same time, the functional fiber paper base can play a certain sealing role, preventing dust, moisture and other impurities from entering the pores of the porous sound-absorbing composite material, which helps to maintain the stability of the sound absorption performance of the porous sound-absorbing composite material and avoid reducing the sound absorption effect due to pore blockage.

[0061] The present disclosure also provides an electronic device, which includes the acoustic composite 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.

[0062] The acoustic composite material block, preparation method and electronic device of the embodiments of the present disclosure have simple processes and utilize a functional fiber paper substrate to wrap a porous sound-absorbing composite material to prepare the acoustic composite material block. Therefore, the functional fiber paper substrate can be made into a suitable size according to the actual size of the speaker cavity, so that an acoustic composite material block of a desired size can be obtained. There is no need to cut the acoustic composite material block, thus avoiding the problem of powder loss and particle shedding during the cutting process.

[0063] In order to verify the effect of the acoustic composite 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.

[0064] Embodiment 1

[0065] The first embodiment of the present disclosure provides an acoustic composite material block, and the preparation method thereof comprises the following steps:

[0066] The first step is to prepare a porous sound-absorbing composite material: weigh 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weigh 15.1g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 2nm and mesopores with a pore size of 40nm, and mix them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0067] The second step is to prepare the functional fiber paper base: weigh 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 benzobisoxazole) fiber), and 1.2g of polyphenylene sulfide fiber. Transfer all the weighed fibers to the combing machine, inject clean water, and comb and disperse for 20 minutes to obtain a functional fiber dispersion. The functional fiber paper base is prepared by wet sheeting. The surface density of the functional fiber paper base is 25g / m 2 .

[0068] The third step is to prepare the acoustic composite material block: the size of the mold tooling: the thickness is 1.2mm and the circular diameter is 1.2cm. Weigh 0.048g of the porous sound-absorbing composite material into a folded packaging bag of a functional fiber paper base, and then transfer it to the mold tooling. This mold tooling has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5MPa to -0.01MPa, the heat treatment temperature is 90℃, the treatment time is 30s, and the mold tooling is opened. The sound-absorbing composite material block can automatically fall off the mold cavity. The body density of the sound-absorbing composite material block is about 0.4g / cm 3 .

[0069] Embodiment 2

[0070] The first embodiment of the present disclosure provides an acoustic composite material block, and the preparation method thereof comprises the following steps:

[0071] The first step is to prepare a porous sound-absorbing composite material: weigh 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weigh 15.1g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 3nm and mesopores with a pore size of 30nm, and mix them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0072] The second step is to prepare the functional fiber paper base: weigh 0.48g of acrylic pulp fiber and polyvinyl alcohol fiber, 0.63g of PET precipitated fiber and glass fiber cotton fiber, 0.90g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and 1.2g of polyphenylene sulfide fiber. Transfer all the weighed fibers to the combing machine, inject clean water, and comb and disperse for 20 minutes to obtain a functional fiber dispersion. The functional fiber paper base is prepared by wet sheeting. The surface density of the functional fiber paper base is 25g / m 2 .

[0073] The third step is to prepare the acoustic composite material block: mold tooling size: thickness is 1.2mm, circular diameter is 1.2cm. Weigh 0.068g of porous sound-absorbing composite material into a folded packaging bag of functional fiber paper base, and then transfer it to the mold tooling. This mold tooling has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5MPa to -0.01MPa, the heat treatment temperature is 110℃, the treatment time is 10s, and the mold tooling is opened. The sound-absorbing composite material block can automatically fall off the mold cavity. The body density of the sound-absorbing composite material block is about 0.5g / cm 3 .

[0074] Embodiment 3

[0075] The first embodiment of the present disclosure provides an acoustic composite material block, and the preparation method thereof comprises the following steps:

[0076] The first step is to prepare a porous sound-absorbing composite material: weigh 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weigh 18g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 2nm and mesopores with a pore size of 40nm, and mix them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0077] The second step is to prepare the functional fiber paper base: weigh 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 benzobisoxazole) fiber), and 1.2g of polyphenylene sulfide fiber. Transfer all the weighed fibers to the combing machine, inject clean water, and comb and disperse for 20 minutes to obtain a functional fiber dispersion. The functional fiber paper base is prepared by wet sheeting. The surface density of the functional fiber paper base is 25g / m 2 .

[0078] The third step is to prepare the acoustic composite material block: mold tooling size: thickness 1.0mm, circular diameter 1.0cm. Weigh 0.078g of porous sound-absorbing composite material into a folded packaging bag of functional fiber paper base, and then transfer it to the mold tooling. This mold tooling has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5MPa to -0.01MPa, the heat treatment temperature is 135℃, the treatment time is 50s, and the mold tooling is opened. The sound-absorbing composite material block can automatically fall off the mold cavity. The body density of the sound-absorbing composite material block is about 0.65g / cm 3 .

[0079] Comparative Example 1

[0080] Comparative Example 1 of the present disclosure provides an acoustic composite material block, and the preparation method thereof comprises the following steps:

[0081] The first step is to prepare a porous sound-absorbing composite material: weigh 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weigh 15.1g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 2nm and mesopores with a pore size of 40nm, and mix them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0082] The second step is to provide PES hot melt adhesive mesh purchased from Shanghai Xianxia Products, with a gram weight of 25g / m 2 , melting range 105℃~120℃, breathable.

[0083] The third step is to prepare an acoustic composite material block: use the above hot melt adhesive mesh to cover the porous sound-absorbing composite material, and perform heat treatment to prepare a composite material block.

[0084] Comparative Example 2

[0085] Comparative Example 2 of the present disclosure provides an acoustic composite material block, and the preparation method thereof comprises the following steps:

[0086] The first step is to prepare a porous sound-absorbing composite material: weigh 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weigh 15.1g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 2nm and mesopores with a pore size of 40nm, and mix them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0087] The second step is to provide filament PP filter non-woven fabric purchased from Shanghai Xinqi Material Technology Co., Ltd., with a gram weight of 25g / m 2 , melting range 105℃~120℃, breathable.

[0088] The third step is to prepare an acoustic composite material block: using the above non-woven fabric to cover and process to prepare a composite material block.

[0089] Comparative Example 3

[0090] The first step: preparing a porous sound-absorbing composite material: weighing 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, 2.32g of aramid fiber and PBO fiber (poly(p-phenylene benzobisoxazole) fiber), and then weighing 15.1g of sound-absorbing particle ZSM-5 molecular sieve, the average particle size of ZSM-5 molecular sieve is 200μm, including micropores with a pore size of 2nm and mesopores with a pore size of 40nm, and mixing them evenly through mechanical stirring to obtain a porous sound-absorbing composite material.

[0091] Step 2: The size of the mold tooling is 1.2mm thick and 1.2cm in diameter. Weigh 0.048g of the porous sound-absorbing composite material into the mold tooling. The mold tooling has negative pressure suction and heat treatment molding functions. The negative pressure range is -0.5MPa to -0.01MPa, the heat treatment temperature is 90℃, and the treatment time is 30s. The mold tooling is opened, and the porous sound-absorbing composite material block can automatically fall off the mold cavity.

[0092] For the acoustic composite material blocks prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 3, the resonance frequency offset value Δf0 of the sheet acoustic enhancement material was tested respectively in accordance with Section 7.4 of the group standard "Porous Sound-Absorbing Particles for Micro Speakers" (Standard No.: T / CECA 78-2022).

[0093] The acoustic efficiency of the sheet acoustic enhancement material per unit mass is calculated according to the following formula:

[0094] Acoustic efficiency = Δf0 / (absolute dry mass of the ball), unit: Hz / mg;

[0095] Finally, the sample performance of this example is expressed as the percentage of acoustic efficiency of the example or comparative example sample:

[0096] Sample acoustic efficiency percentage = (sample acoustic efficiency / acoustic efficiency of the absolute dry mass of the ball)%. The results are shown in Table 1:

[0097] Table 1: Acoustic Enhanced Composite Material Performance Test Data

[0098]

[0099] It can be seen from the above table that the acoustic composite material block prepared in the embodiment of the present disclosure is compared with the acoustic composite material blocks prepared in comparative examples 1 to 3. In comparative example 1, a hot melt adhesive mesh is used to replace the functional fiber paper base of the embodiment of the present disclosure, and in comparative example 2, a non-woven fabric is used to replace the functional fiber paper base of the embodiment of the present disclosure, and comparative example 3 does not contain the functional fiber paper base of the embodiment of the present disclosure. Finally, the acoustic efficiency percentage of the sample of the acoustic composite material block prepared in the embodiment of the present disclosure is higher, and there is no shedding or powdering in the 100-time drop test at a height of 1m, and the acoustic efficiency is more durable. It can be seen that the acoustic composite material block in the embodiment of the present disclosure uses a functional fiber paper base to wrap a porous sound-absorbing composite material to prepare an acoustic composite material block. Under the joint action of the functional fiber paper base and the porous sound-absorbing composite material, the acoustic composite material block is not only not easy to shed powder and fall off, but also has better acoustic performance.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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. A method for preparing an acoustic composite material block, characterized in that: include: Wet-forming the functional fibers into a functional fiber paper base; Using the functional fiber paper substrate to wrap the porous sound-absorbing composite material to obtain a prefabricated acoustic composite material block; The prefabricated acoustic composite material block is heat treated under negative pressure conditions so that the functional fiber paper base is bonded to the porous sound-absorbing composite material to obtain an acoustic composite material block.

2. The method for preparing an acoustic composite material block according to claim 1, characterized in that: Before wrapping the porous sound-absorbing composite material with the functional fiber paper substrate, the method further comprises: The first supporting fibers, the first bonding fibers, the first wave-transmitting fibers and the sound-absorbing particles are mixed to obtain a porous sound-absorbing composite material.

3. The method for preparing an acoustic composite material block according to claim 2, characterized in that: The mass ratio of the first supporting fibers, the first bonding fibers, the first wave-transmitting fibers and the sound-absorbing particles is (5-50): (5-50): (5-50): (50-95).

4. The method for preparing an acoustic composite material block according to claim 3, characterized in that: The first supporting fiber comprises at least one of glass fiber wool, aramid pulp, polyethylene terephthalate fibrid and poly(p-phenylene benzobisoxazole) fiber; The first bonding fiber comprises at least one of polyvinyl alcohol fiber, polyethylene fiber, polyethylene fiber pulp, polypropylene fiber, acrylic fiber pulp, polyester fiber and polyester fiber pulp; The first wave-transmitting fiber comprises at least one of poly(p-phenylene benzobisoxazole) fiber, quartz fiber, aramid 1313, silica fiber, aramid 1414, aramid pulp, aramid fibrid, polyimide fiber and boron nitride wave-transmitting fiber; The sound-absorbing particles include at least one of zeolite molecular sieve, activated silicon dioxide, activated carbon, calcium carbonate, calcium silicate, aluminum oxide, hydrogel and aerogel.

5. The method for preparing an acoustic composite material block according to claim 1, characterized in that: The method of wrapping the porous sound-absorbing composite material with the functional fiber paper substrate to obtain a prefabricated acoustic composite material block comprises: Making the functional fiber paper base into a packaging bag; The porous sound-absorbing composite material is placed in the packaging bag so that the functional fiber paper base wraps the porous sound-absorbing composite material to obtain a prefabricated acoustic composite material block.

6. The method for preparing an acoustic composite material block according to claim 1, characterized in that: The process conditions of the heat treatment include: the heat treatment temperature is 85° C. to 135° C., and the heat treatment time is 10s to 50s.

7. The method for preparing an acoustic composite material block according to any one of claims 1 to 6, characterized in that: The surface density of the functional fiber paper base is 20m 2 ~200g / m 2 The tensile strength of the functional fiber paper base is ≥3MPa, and the porosity of the functional fiber paper base is ≥90%.

8. The method for preparing an acoustic composite material block according to any one of claims 1 to 6, characterized in that: The bulk density of the acoustic composite material block is equal to 0.4 g / cm 3 ~0.65g / cm 3 .

9. The method for preparing an acoustic composite material block according to any one of claims 1 to 6, characterized in that: The functional fiber includes a second bonding fiber, a second supporting fiber, a second wave-transmitting fiber and a heat-shrinkable fiber, and the mass ratio of the second bonding fiber, the second supporting fiber, the second wave-transmitting fiber and the heat-shrinkable fiber is (12-18): (8-13): (30-35): (16-25).

10. The method for preparing an acoustic composite material block according to claim 9, characterized in that: The second bonding fiber comprises at least one of polyvinyl alcohol fiber, polyethylene fiber, polyethylene fiber pulp, polypropylene fiber, acrylic fiber pulp, polyester fiber and polyester fiber pulp; The second supporting fiber comprises at least one of glass fiber wool, aramid pulp, polyethylene terephthalate fibrid and poly(p-phenylene benzobisoxazole) fiber; The second wave-transmitting fiber comprises at least one of poly(p-phenylene benzobisoxazole) fiber, quartz fiber, aramid 1313, silica fiber, aramid 1414, aramid pulp, aramid fibrid, polyimide fiber and boron nitride wave-transmitting fiber; The heat shrinkable fiber includes at least one of polyphenylene sulfide fiber, nylon fiber, polyethylene fiber, polypropylene fiber and polyester fiber.

11. The method for preparing an acoustic composite material block according to claim 10, characterized in that: The heat shrinkable fiber has a dry heat shrinkage rate of 30% to 50% in a temperature range of 90° C. to 180° C., a breaking elongation of ≥30%, and a breaking strength of ≥2 cN / dtex.

12. An acoustic composite material block, prepared according to the method for preparing an acoustic composite material block according to any one of claims 1 to 11, characterized in that: The acoustic composite material block comprises a porous sound-absorbing composite material and a functional fiber layer wrapped on the outer surface of the porous sound-absorbing composite material, the porous sound-absorbing composite material is bonded to the functional fiber layer, and the functional fiber layer has a three-dimensional mesh structure.

13. An electronic device, characterized in that: The electronic device comprises the acoustic composite material block of claim 12.

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