Sound-absorbing material block, preparation method thereof, and speaker box using the sound-absorbing material block

Abstract

The present invention provides a sound-absorbing material block, the sound-absorbing material block comprising porous sound-absorbing particles, an organic support material, a binder and a thickener, the porous sound-absorbing particles are adhered to the organic support material through the binder, and the particle size of the porous sound-absorbing particles is 10-100 μm. The present invention also provides a method for preparing a sound-absorbing material block and a speaker box using the sound-absorbing material block. The sound-absorbing material block and the preparation method thereof provided by the present invention and the speaker box using the sound-absorbing material block not only give full play to the high-performance characteristics of small-size sound-absorbing particles, but also meet the development trend of miniaturization of speaker boxes; by combining the porous sound-absorbing particles with the organic support material, the stability of the sound-absorbing material block in the back cavity of the speaker box is improved, and the reduction of acoustic performance caused by particle vibration is effectively avoided.

Description

[Technical field]

[0001] The invention relates to the technical field of sound absorbing materials, and in particular to a sound absorbing material block and a preparation direction thereof, and a speaker box using the sound absorbing material block. [Background technology]

[0002] With the continuous development of smart mobile terminals such as mobile phones, thinness has become a trend. Therefore, the space occupied by the back cavity of audio speakers has been further reduced. Generally speaking, the reduction of the back cavity of the speaker will significantly reduce the response of the low frequency band, resulting in poor sound quality. In order to solve this contradiction, the back cavity is usually filled with sound-absorbing materials that can absorb sound, virtually increasing the volume of the back cavity and achieving the purpose of improving sound quality.

[0003] In the related art, there are two commonly used forms of sound-absorbing materials. The first is granular sound-absorbing materials, which have the characteristic that the smaller the particle size, the higher the sound absorption performance; however, it is difficult for granular sound-absorbing materials to fill the back cavity during filling. When the speaker box is working, the vibration of the gas in the back cavity causes the particles to vibrate. The smaller the particle size, the more significant the vibration, the worse the hearing, and there is even a risk of diffusing through the mesh to the inside of the speaker unit and damaging the speaker unit. The second is block sound-absorbing materials, such as sound-absorbing materials with foam as the skeleton, which still have the disadvantages of sound-absorbing powder agglomeration, poor air permeability, high sound resistance, and low sound absorption performance.

[0004] Therefore, it is necessary to provide a new sound absorbing material block and a preparation method thereof and a speaker box using the sound absorbing material block to solve the above technical problems. [Summary of the invention]

[0005] The purpose of the present invention is to overcome the above-mentioned technical problems and provide a sound-absorbing material block and a preparation method thereof and a speaker box using the sound-absorbing material block. The sound-absorbing material block gives full play to the characteristics of small-diameter sound-absorbing particles with high sound absorption performance, effectively improves the stability of the sound-absorbing material block in the back cavity, avoids the change of acoustic performance caused by particle vibration, and effectively prevents the sound-absorbing material block from entering the speaker unit and damaging the acoustic performance of the speaker box.

[0006] To achieve the above object, the present invention provides a sound-absorbing material block, which includes porous sound-absorbing particles, an organic support material, a binder and a thickener. The porous sound-absorbing particles are adhered to the organic support material through the binder, and the particle size of the porous sound-absorbing particles is 10-100 μm.

[0007] Preferably, the porous sound-absorbing particles are composed of porous particles with a particle size of less than 10 μm, and the porous particles include zeolite and activated carbon.

[0008] Preferably, the zeolite has at least one structure of MFI, MEL and FER.

[0009] Preferably, the organic support material has a two-dimensional structure, the organic support material comprises one of PE, PP, PVC and PET films, and the thickness of the organic support material is 10-100 μm.

[0010] Preferably, the organic scaffold material has a three-dimensional structure, and the organic scaffold material includes one of melamine foam, polyurethane foam and polyethylene foam.

[0011] Preferably, the density of the organic scaffold material is 1-10 mg / cm3, the organic scaffold material comprises a plurality of through holes, the porosity of the organic scaffold material is greater than 50%, and the average pore size of the through holes is 50-300 μm.

[0012] Preferably, the binder comprises at least one of polyacrylate, polystyrene acrylate, polystyrene acetate and polyethyl vinyl acetate, and the sound absorbing material block comprises 2-10 wt % of the binder.

[0013] Preferably, the thickener comprises at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol, and the sound absorbing material block comprises 0.5-2 wt % of the thickener.

[0014] The present invention also provides a method for preparing the above-mentioned sound-absorbing material block, which comprises the following steps:

[0015] After sintering or bonding the porous particles, an extrusion spheronization process or a spray granulation process is used to prepare the porous sound-absorbing particles with a particle size of 10-100 μm;

[0016] Mixing the porous sound-absorbing particles with the binder and the thickener to form a slurry;

[0017] The organic support material is immersed in the slurry and left to stand for 5-20 minutes before drying to obtain the sound absorbing material block.

[0018] The present invention also provides a speaker box, which includes a shell having a receiving space and a speaker unit received in the receiving space, wherein the speaker unit and the shell are arranged to form a rear cavity, and the rear cavity is filled with the above-mentioned sound absorbing material block.

[0019] Compared with the related art, the sound-absorbing material block provided by the present invention comprises porous sound-absorbing particles, an organic support material, a binder and a thickener, wherein the porous sound-absorbing particles are adhered to the organic support material by the binder, and the particle size of the porous sound-absorbing particles is 10-100 μm, which not only gives full play to the high-performance characteristics of small-size sound-absorbing particles, but also meets the development trend of miniaturization of speaker boxes; by combining it with the organic support material, the stability of the sound-absorbing material block in the back cavity of the speaker box is improved, the reduction of acoustic performance caused by particle vibration is effectively avoided, and the sound-absorbing material block is prevented from entering the speaker unit; and the sound-absorbing material block provided by the present invention can be applied to back cavities of different shapes, eliminating the step of filling the granular sound-absorbing material into the back cavity of the speaker box, and simplifying the assembly process of the speaker box.

Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0021] Figure 1 A flowchart of a method for preparing a sound-absorbing material block provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the speaker box structure provided by the present invention. [Specific implementation method]

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The invention relates to a sound absorbing material block, which comprises porous sound absorbing particles, an organic support material, a binder and a thickener. The porous sound absorbing particles are adhered to the organic support material through the binder, and the particle size of the porous sound absorbing particles is 10-100 μm.

[0025] The porous sound-absorbing particles are composed of a plurality of porous particles with a particle size of less than 10 μm, and the porous particles include zeolite and activated carbon; specifically, the zeolite includes at least one structure of MFI, MEL and FER. It is worth mentioning that different zeolite structures only have slightly different pore structures, and both pure phase zeolite and mixed phase zeolite have good sound absorption effects, and the specific structure of zeolite does not affect the technical effect of the present invention.

[0026] The organic scaffold material has a two-dimensional structure. Accordingly, the organic scaffold material can be selected from one of PE, PP, PVC, and PET films. In order to make the organic scaffold material play a better role in supporting the skeleton, the thickness of the selected organic scaffold material is between 10-100 μm. Of course, it is worth mentioning that in order to make the organic scaffold material better and more evenly carry the porous sound-absorbing particles, an organic scaffold material with a three-dimensional structure can also be selected. Specifically, it can be selected from one of melamine foam, polyurethane foam, and polyethylene foam. Compared with the aforementioned two-dimensional structure, the organic scaffold material with a three-dimensional structure can not only bond the porous sound-absorbing particles on the surface, but also the pore structure inside it can adsorb the porous sound-absorbing particles, further improving the sound absorption capacity of the sound-absorbing material block. The density of the organic scaffold material selected in the present invention is 1-10 mg / cm3. It can be understood that the organic scaffold material includes a plurality of through holes, and the porosity of the organic scaffold material is greater than 50%; in order to make the organic scaffold material better bond the porous sound-absorbing particles, the average pore size of the through holes in the organic scaffold material is set to 50-300 μm.

[0027] The binder includes at least one of polyacrylate, polystyrene acrylate, polystyrene acetate, and polyethyl vinyl acetate salt. In order to allow the porous sound-absorbing particles to be firmly adsorbed on the organic support material and avoid affecting the acoustic performance of the speaker box due to the vibration and shedding of the particles, the sound-absorbing material block includes 2-10wt% of the binder by mass.

[0028] The thickener includes at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol. Specifically, the sound absorbing material block includes 0.5-2 wt % of the thickener.

[0029] The present invention also provides a method for preparing the above-mentioned sound-absorbing material block, the specific process is combined with Figure 1 Provide explanation.

[0030] Step 1: After sintering or bonding the porous particles, an extrusion spheronization process or a spray granulation process is used to prepare porous sound-absorbing particles with a particle size of 10-100 μm;

[0031] Step 2: Mix the porous sound-absorbing particles with a binder and a thickener to form a slurry;

[0032] Step 3: Immerse the organic support material in the above slurry, and after standing for 5-20 minutes, dry the organic support material and the slurry to obtain a sound-absorbing material block.

[0033] In step 3, the drying step is carried out in an oven, and the drying temperature is set at about 100 degrees Celsius.

[0034] The following will explain the implementation of the present invention in conjunction with specific examples.

[0035] Example 1

[0036] This embodiment provides a method for preparing a sound-absorbing material block, which comprises the following steps:

[0037] According to the mass ratio, 50 parts of zeolite, 45 parts of water and 5 parts of polystyrene acrylate were weighed and mixed evenly, and porous sound-absorbing particles were prepared by extrusion spheronization granulation process. Specifically, after granulation, porous sound-absorbing particles with a particle size of about 50-100 μm were sieved using a 150-300 mesh sieve.

[0038] Weigh 1 part of styrene acrylate, 0.2 part of sodium hydroxymethyl cellulose, 50 parts of deionized water, and 5 parts of 98wt% ethanol, mix and stir to obtain a mixed solution; weigh 50 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0039] A PET film with a thickness of 25 μm was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0040] Example 2

[0041] This embodiment provides a method for preparing a sound-absorbing material block, which comprises the following steps:

[0042] According to the mass ratio, 50 parts of zeolite, 45 parts of water and 5 parts of polystyrene acrylate were weighed and mixed evenly, and porous sound-absorbing particles were prepared by extrusion spheronization granulation process. Specifically, after granulation, porous sound-absorbing particles with a particle size of about 50-100 μm were sieved using a 150-300 mesh sieve.

[0043] Weigh 1 part of styrene acrylate, 0.2 part of sodium hydroxymethyl cellulose, 50 parts of deionized water, and 5 parts of 98wt% ethanol, mix and stir to obtain a mixed solution; weigh 40 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0044] Melamine foam with an average pore size of 100-200 μm and a density of 5 mg / cm3 was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0045] Example 3

[0046] This embodiment provides a method for preparing a sound-absorbing material block, which comprises the following steps:

[0047] According to the mass ratio, 50 parts of zeolite, 40 parts of water, 5 parts of polyacrylate and 5 parts of hydrogen peroxide were weighed and mixed evenly, and porous sound-absorbing particles were prepared by a spray granulation process. Specifically, after granulation, a 150-300 mesh sieve was used to screen out porous sound-absorbing particles with a particle size of about 50-100 μm.

[0048] Weigh 3 parts of polyacrylate, 0.1 parts of polyvinyl alcohol, 50 parts of deionized water, and 5 parts of 98 wt% ethanol, mix and stir to obtain a mixed solution; weigh 40 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0049] Melamine foam with an average pore size of 100-200 μm and a density of 5 mg / cm3 is immersed in the above slurry, left for 10 minutes, taken out, and placed in an oven at a temperature higher than 100 degrees Celsius for drying to obtain a sound-absorbing material block.

[0050] Example 4

[0051] This embodiment provides a method for preparing a sound-absorbing material block, which comprises the following steps:

[0052] According to the mass ratio, 50 parts of zeolite, 40 parts of water, 5 parts of styrene butadiene emulsion and 5 parts of hydrogen peroxide were weighed and mixed evenly, and porous sound-absorbing particles were prepared by extrusion spheronization granulation process. Specifically, after granulation, porous sound-absorbing particles with a particle size of about 50-100 μm were sieved using a 150-300 mesh sieve.

[0053] Weigh 2 parts of styrene butadiene emulsion, 0.2 parts of sodium hydroxymethyl cellulose, 50 parts of deionized water, and 5 parts of 98wt% ethanol, mix and stir to obtain a mixed solution; weigh 20 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0054] The polyurethane foam with an average pore size of 200-300 μm and a density of 3 mg / cm3 was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at a temperature of 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0055] Example 5

[0056] This embodiment provides a method for preparing a sound-absorbing material block, which comprises the following steps:

[0057] According to the mass ratio, 50 parts of activated carbon, 40 parts of water, 5 parts of polyacrylate and 5 parts of hydrogen peroxide were weighed and mixed evenly, and porous sound-absorbing particles were prepared by a spray granulation process. Specifically, after granulation, a 150-300 mesh sieve was used to sieve out porous sound-absorbing particles with a particle size of about 50-100 μm.

[0058] Weigh 1 part of polyacrylate, 0.1 part of polyvinyl alcohol, 50 parts of deionized water, and 5 parts of 98wt% ethanol, mix and stir to obtain a mixed solution; weigh 40 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0059] Melamine foam with an average pore size of 100-200 μm and a density of 7 mg / cm3 was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at a temperature of 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0060] In addition, in order to verify the effect of the technical solution of the present invention, two comparative examples are provided as follows.

[0061] Comparative Example 1

[0062] According to the mass ratio, 50 parts of zeolite, 45 parts of water and 5 parts of polystyrene acrylate were weighed and mixed evenly, and porous sound-absorbing particles were prepared by extrusion spheronization granulation process. Specifically, after granulation, porous sound-absorbing particles with a particle size of about 100-250 μm were sieved using a 60-150 mesh sieve.

[0063] Weigh 2 parts of styrene acrylate, 0.2 parts of sodium hydroxymethyl cellulose, 50 parts of deionized water, and 5 parts of 98 wt% ethanol, mix and stir to obtain a mixed solution; weigh 40 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0064] Melamine foam with an average pore size of 100-200 μm and a density of 5 mg / cm3 was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at a temperature of 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0065] Comparative Example 2

[0066] According to the mass ratio, 50 parts of zeolite, 45 parts of water and 5 parts of polystyrene acrylate were weighed and mixed evenly, and porous sound-absorbing particles were prepared by a spray granulation process. Specifically, after granulation, porous sound-absorbing particles with a particle size of about 50-100 μm were sieved using a 150-300 mesh sieve.

[0067] Weigh 4 parts of styrene acrylate, 0.2 parts of polyvinyl alcohol, 50 parts of deionized water, and 5 parts of 98wt% ethanol, mix and stir to obtain a mixed solution; weigh 40 parts of the porous sound-absorbing particles prepared above, add them to the mixed solution, continue stirring for 30 minutes, and evenly disperse the porous sound-absorbing particles in the mixed solution to form a slurry.

[0068] Melamine foam with an average pore size of 50-100 μm and a density of 10 mg / cm3 was immersed in the above slurry, left for 5 minutes, taken out, and placed in an oven at a temperature of 110 degrees Celsius for drying to obtain a sound-absorbing material block.

[0069] The acoustic performance tests were conducted on the sound absorbing material blocks prepared in Examples 1-5 and Comparative Examples 1-2 of the present invention, as well as conventional sound absorbing particle samples in the art, wherein the sample of Example 1 was tested by a multilayer film stacking test. The test conditions of the test fixture were 50% of the volume filling amount and 0.5 ml of the back cavity volume. The test results are shown in Table 1:

[0070] Table 1 Acoustic performance test results

[0071] sample Resonance frequency decreases ΔF0(Hz) Example 1 119 Example 2 126 Example 3 132 Example 4 114 Example 5 109 Comparative Example 1 32 Comparative Example 2 46 Conventional sound-absorbing particles 106

[0072] It can be seen from Table 1 that, under the condition of the same acoustic filling volume, the sound-absorbing material blocks prepared in Examples 1-5 of the present invention have significantly better acoustic performance than conventional sound-absorbing particles in the art, so that the speaker box filled with the sound-absorbing material blocks has better low-frequency performance. In addition, in the working state of the speaker box, the sound-absorbing material blocks provided by the present invention will not have changes in acoustic performance due to particle collision and movement, and the organic support material as a carrier can be adjusted according to the shape of the back cavity, so as to fill the back cavity to the maximum extent, so that the low-frequency effect of the speaker box is better. Furthermore, in the process of assembling the speaker box, the sound-absorbing material block can be easily placed in the back cavity, eliminating the steps of filling particles, etc., and improving the preparation efficiency of the speaker box.

[0073] The performance of Comparative Examples 1-2 is significantly lower than that of Examples 2-5 and conventional samples, because the diameter of the porous sound-absorbing particles does not match the pore size of the foam with a three-dimensional structure. During the preparation process, the porous sound-absorbing particles failed to completely enter the foam, but only formed a layer of sound-absorbing particles on the surface of the foam.

[0074] The surface area of ​​the two-dimensional sound-absorbing particle layer formed in Example 1 is larger than that of Example 1-2, and the performance is better.

[0075] The present invention also provides a speaker box 100, such as Figure 2 As shown, it includes a shell 1 with a receiving space and a speaker unit 2 received in the receiving space; the speaker unit 2 and the shell 1 are arranged to form a rear cavity 3, and the rear cavity 3 is filled with the above-mentioned sound-absorbing material block to increase the acoustic compliance of the air in the rear cavity, thereby improving the low-frequency acoustic performance of the speaker.

[0076] Compared with the related art, the sound-absorbing material block provided by the present invention comprises porous sound-absorbing particles, an organic support material, a binder and a thickener, wherein the porous sound-absorbing particles are adhered to the organic support material by the binder, and the particle size of the porous sound-absorbing particles is 10-100 μm, which not only gives full play to the high-performance characteristics of small-size sound-absorbing particles, but also meets the development trend of miniaturization of speaker boxes; by combining it with the organic support material, the stability of the sound-absorbing material block in the back cavity of the speaker box is improved, the reduction of acoustic performance caused by particle vibration is effectively avoided, and the sound-absorbing material block is prevented from entering the speaker unit; and the sound-absorbing material block provided by the present invention can be applied to back cavities of different shapes, eliminating the step of filling the granular sound-absorbing material into the back cavity of the speaker box, and simplifying the assembly process of the speaker box.

[0077] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A sound-absorbing material block, characterized in that: The sound-absorbing material block comprises porous sound-absorbing particles, an organic support material, a binder and a thickener, wherein the porous sound-absorbing particles are adhered to the organic support material through the binder, and the particle size of the porous sound-absorbing particles is 10-100 μm; the organic support material has a three-dimensional structure and comprises a plurality of through holes, the porosity of the organic support material is greater than 50%, and the average pore size of the through holes is 50-300 μm; the porous sound-absorbing particles are adsorbed onto the surface of the organic support material and into the through holes.

2. The sound absorbing material block according to claim 1, characterized in that: The porous sound-absorbing particles are composed of porous particles with a particle size of less than 10 μm, and the porous particles include zeolite and activated carbon.

3. The sound absorbing material block according to claim 2, characterized in that: The zeolite has at least one structure of MFI, MEL and FER.

4. The sound absorbing material block according to claim 1, characterized in that: The organic support material includes one of melamine foam, polyurethane foam and polyethylene foam.

5. The sound absorbing material block according to claim 4, characterized in that: The density of the organic scaffold material is 1-10 mg / cm3.

6. The sound absorbing material block according to claim 1, characterized in that: The binder comprises at least one of polyacrylate, polystyrene acrylate, polystyrene acetate and polyethyl vinyl acetate salt, and the sound absorbing material block comprises 2-10 wt % of the binder.

7. The sound absorbing material block according to claim 1, characterized in that: The thickener comprises at least one of sodium alginate, sodium hydroxymethyl cellulose and polyvinyl alcohol, and the sound absorbing material block comprises 0.5-2 wt % of the thickener.

8. A speaker box, comprising a shell having a receiving space, and a speaker unit received in the receiving space, wherein the speaker unit and the shell are arranged to form a rear cavity, wherein: The rear cavity is filled with the sound absorbing material block as claimed in claim 1.

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