Hearing protection earmuff material based on nano-pore structure and application of hearing protection earmuff material

Abstract

The invention relates to the technical field of hearing protection earmuffs, in particular to a hearing protection earmuff material based on a nano-pore structure and application of the hearing protection earmuff material. The nanometer bionic noise-reduction hearing protection earmuff can effectively reduce noise by 30-40 decibels, so that knocking sound entering ears does not exceed 110 decibels, the noise of a working environment is reduced to be lower than 80 decibels, and the national standard (continuous working for 8 hours under 85 decibels) for noise environment operation can be met; for the low-frequency wave band (63Hz) where noise reduction is most difficult, the maximum noise reduction effect of the nanometer bionic noise reduction hearing protection earmuff can reach 34.56 dB, and health and safety of operators can be fully guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of hearing protection earmuffs, and in particular to a hearing protection earmuff material based on a nanopore structure and an application thereof. Background Art

[0002] With the development of social economy and the acceleration of urbanization, noise pollution is becoming increasingly serious. Various types of noise, such as industrial noise, construction noise, traffic noise and life noise, not only damage the human auditory system, but also cause dysfunction of the central nervous system, cardiovascular system, digestive system and endocrine system, and even lead to mental disorders and impaired reproductive function. Among them, low-frequency noise (such as the "buzzing" sound produced by mechanical motors and mechanical vibrations) is particularly difficult to resist, and existing noise reduction technologies have limited effect on this.

[0003] Although low-frequency noise does not sound as harsh as high-frequency noise, it has greater energy, propagates farther, and is more hidden and lasting in its harm to the human body. Especially in industrial environments, low-frequency noise is often the main source of noise, and ordinary hearing protection earmuffs cannot effectively resist this type of noise. In order to solve the above problems, the most effective noise reduction technology at present is active noise reduction technology, which offsets external noise by emitting reverse sound waves. Although this technology has a good noise reduction effect on stable environmental noise, it cannot cope with scenes dominated by low frequencies and containing sudden noise. The noise reduction effect under low-frequency noise is generally less than 30 decibels. In addition, the existing active noise reduction is not full-band noise reduction, and it cannot effectively reduce noise in the mid- and high-frequency bands, which also limits the application scenarios of existing hearing protection earmuffs.

[0004] The instantaneous noise of a jet aircraft taking off can reach 140 decibels, which is enough to cause permanent damage to the human auditory system. Ship engine room mechanics and airport staff need to work in a high noise environment of 110 decibels for a long time. These are typical low-frequency dominated and sudden noise scenes. According to national standards, operators shall not work continuously for more than 15 minutes in a noise environment above 100 decibels, and the instantaneous noise in the working scene shall not exceed 115 decibels, otherwise it will cause irreversible hearing damage to the operator.

[0005] The national qualification standard for working in a noisy environment is 85 decibels for 8 hours continuously. The existing hearing protection earmuffs are not ideal in the above-mentioned low-frequency noise environment, do not meet the national working standards, and cannot provide adequate hearing protection for workers, causing them to be exposed to high-noise environments for a long time and face the risk of hearing damage. Improvement is urgently needed. Summary of the invention

[0006] In order to enhance the noise reduction effect of earmuffs in scenes dominated by low frequencies and containing sudden noises, while ensuring the noise reduction effect of earmuffs on mid- and high-frequency noises, the present application provides a hearing protection earmuff material based on a nanoporous structure and its application.

[0007] The hearing protection earmuff material based on nanoporous structure and its application provided in the present application adopt the following technical solutions:

[0008] In a first aspect, the present application provides a method for preparing a hearing protection earmuff material based on a nanoporous structure, using the following technical solution:

[0009] A method for preparing a hearing protection earmuff material based on a nano-void structure comprises the following steps:

[0010] S1, dispersing nano powder in liquid to form a mixed liquid;

[0011] S2, heating the mixed solution to 30-50° C., and dispersing by ultrasonic vibration to obtain a dispersion;

[0012] S3, placing the porous material in a vacuum box, soaking it in the dispersion, and evacuating the material until bubbles appear in the dispersion; then stopping the evacuation, and oscillating the material to expel the remaining gas in the porous material;

[0013] S4, taking out the porous material that absorbed the mixed solution in S3, and drying it at 50-80°C;

[0014] S5, repeating steps S3 and S4 for several times until the nano powder content in the porous material obtained after drying reaches 500-1000 mol / m 3 .

[0015] By adopting the above technical solution, through ultrasonic dispersion, step-by-step vacuum impregnation and repeated drying processes, it is ensured that the nanopowder forms a uniform and high-density pore structure inside the porous material, significantly improving the low-frequency sound absorption performance, thereby optimizing the noise reduction effect of the material.

[0016] Preferably, in S1, the nanopowder is any one of graphene oxide, carbon nanotubes, and boron nitride, and the content of the nanopowder in the mixed solution is 0.15-0.3 mol / L.

[0017] By adopting the above technical solution, the types and concentration range of nanopowders are limited, the dispersibility and loading amount are balanced, and material waste or performance saturation is avoided.

[0018] Preferably, in S1, the liquid is a mixed solution of pure water and alcohol, and the alcohol content is 5-30% vol.

[0019] By adopting the above technical solution, alcohol reduces the surface tension of the liquid and accelerates the wetting and dispersion of the nanoparticles. However, when the alcohol content is too high, the saturated vapor pressure of the solution increases, resulting in the solution starting to boil when the vacuum degree required for defoaming is not reached during vacuum defoaming, which is not conducive to the solution penetrating into the porous material. The present application limits the alcohol concentration to ensure the dispersion efficiency of the nanopowder while preventing the solution from boiling prematurely, thereby ensuring that the mixed liquid completely fills the pores of the porous material.

[0020] Preferably, in S3, the porous material is a polymer foam material, specifically any one of polyurethane sponge, melamine sponge, and polyester fiber.

[0021] By adopting the above technical solution, the polymer foam material has both flexibility and sound absorption performance.

[0022] Preferably, in S5, steps S3 and S4 are repeated 3-8 times.

[0023] By adopting the above technical solution, the study found that limiting the number of repeated immersion-drying to 3-8 times can ensure that the nanopowder loading meets the standard, maximize the sound absorption performance, and save production costs.

[0024] In a second aspect, the present application provides an application of a hearing protection earmuff material based on a nanoporous structure, using the following technical solution:

[0025] An application of a hearing protection earmuff material based on a nanoporous structure comprises the following steps:

[0026] A1. According to the shape of the earmuff shell, the porous material obtained in S5 is polished and shaped to obtain the earmuff liner;

[0027] A2. Grinding the cavity on the earmuff inner shell side;

[0028] A3, fixing the earmuff inner liner after grinding the cavity to the earmuff shell to obtain the protective earmuff.

[0029] By adopting the above technical solutions and through customized polishing and cavity design of the earmuff liner, the sound wave reflection path is optimized and the low-frequency noise reduction effect is improved.

[0030] Preferably, in A3, after polishing, the cavity is semi-ellipsoidal, and the distance from the deepest part of the cavity to the ear is not less than 2 cm.

[0031] By adopting the above technical solution, insufficient cavity depth will cause the resonance frequency to shift to the mid-to-high frequency bands, weakening the low-frequency sound absorption effect. The spacing design greater than or equal to 2 cm can buffer the energy of sudden explosive sounds and protect hearing safety.

[0032] Preferably, in A3, a sealing coating having flexibility and elasticity is applied between the earmuff shell and the earmuff liner to fix the earmuff liner and the earmuff shell.

[0033] By adopting the above technical solution, the sealing coating can enhance the structural stability and isolate the external noise leakage, while the flexible coating can maintain the sealing property as the earmuff deforms.

[0034] Preferably, the sealing coating is any one of silicone grease, fluoro grease and vaseline.

[0035] In summary, the beneficial effects of this application are as follows:

[0036] After studying how the human body protects its own auditory system, it was found that the cochlea and other auditory organs are protected by a series of transparent and flexible pore structures. These flexible pore structures can dissipate the energy of noise sound waves through vibration. The smaller and denser the pore structure, the better its protection against low-frequency noise.

[0037] Based on this principle, the present application starts from the perspective of bionics and imitates the hearing protection structure of transparent nanopores in the human auditory system. The nano-bionic noise-reducing hearing protection earmuffs designed in the present application can effectively reduce noise by 30-40 decibels, so that the blast sound entering the ear does not exceed 110 decibels, and the noise in the working environment is reduced to below 80 decibels, which can meet the national standards for working in a noisy environment (continuous work for 8 hours at 85 decibels); for the low-frequency band (63Hz) that is most difficult to reduce noise, the nano-bionic noise-reducing hearing protection earmuffs of the present application can achieve a maximum noise reduction effect of 34.56dB, which can fully guarantee the health and safety of operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 This is a physical picture of the nanoporous structure noise reduction material.

[0040] Figure 2 This is a physical picture of the polished earmuff liner.

[0041] Figure 3 This is a diagram of the composition of hearing protection earmuffs based on nanoporous structure. DETAILED DESCRIPTION

[0042] The following will be combined with the attached Figure 1-3, the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products, or devices.

[0044] raw material

[0045] Nano powder: any one of graphene oxide, carbon nanotubes, and boron nitride can be selected. The embodiment of the present application takes graphene oxide as an example.

[0046] Liquid: a mixed solution of pure water and alcohol, wherein the alcohol content is preferably 5-30% vol., and the alcohol content of 30% vol is used as an example in the embodiment of the present application.

[0047] Porous material: preferably a polymer foam material, specifically any one of polyurethane sponge, melamine sponge, and polyester fiber. The embodiment of the present application takes polyurethane sponge as an example.

[0048] Sealing coating: any one of silicone grease, fluoro grease, and vaseline. The embodiment of the present application takes silicone grease as an example.

[0049] Commercially available hearing protection earmuffs: Edifier W860NB active noise reduction earmuffs.

[0050] Example

[0051] Example 1

[0052] A method for preparing a hearing protection earmuff based on a nanoporous structure includes preparing a material and making the earmuff using the material, as follows:

[0053] S1. Take an appropriate amount of nano powder, add it to liquid, and stir to obtain a mixed solution, wherein the content of nano powder in the mixed solution is 0.2 mol / L.

[0054] S2. The mixed solution is heated to 40° C. and subjected to ultrasonic vibration for 3 h to ensure that the nanopowder in the solution is evenly dispersed, thereby obtaining a dispersion.

[0055] S3. Place the porous material in the dispersion solution immersed in a vacuum box, and evacuate the mixture until bubbles begin to appear; then stop evacuating the mixture, vibrate the vacuum box, and exhaust the gas in the porous material until no bubbles are generated.

[0056] S4. Take out the porous material that has fully absorbed the dispersion and dry it at a temperature of 60°C. If ordinary circulating air drying equipment is used for drying, the drying time is 24-36 hours. If microwave drying equipment is used for drying, the drying time is 0.5-10 hours. In Example 1 of the present application, drying with ordinary circulating air drying equipment is used as an example, and the drying time is 36 hours.

[0057] S5. Repeat steps S3 and S4 3-8 times until the nano powder content in the porous material reaches 500-1000 mol / m 3 The specific number of repetitions is adjusted according to the actual situation to obtain the actual object. Figure 1 .

[0058] S6, according to the shape of the earmuff shell, the porous material obtained in S5 is polished and formed to make the earmuff liner, as shown in the following figure: Figure 2 shown.

[0059] S7. Grind a cavity on the side of the earmuff inner shell close to the ear. After grinding, the cavity is semi-ellipsoidal, and the distance from the deepest part of the cavity to the ear is not less than 2 cm.

[0060] S8, applying a sealing coating between the earmuff shell and the earmuff liner, fixing the earmuff liner and the earmuff shell, and obtaining the hearing protection earmuff. The composition diagram of the finished hearing protection earmuff is as shown in FIG. Figure 3 shown.

[0061] Example 2

[0062] The difference between Example 2 and Example 1 is that in Example 2, in step S1, the liquid is pure water rather than a mixed solution of pure water and alcohol.

[0063] Comparative Example

[0064] Comparative Example 1

[0065] Comparative Example 1 uses commercially available hearing protection earmuffs.

[0066] Comparative Example 2

[0067] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the cavity polishing step is not provided, and the details are as follows:

[0068] A method for preparing a hearing protection earmuff based on a nanoporous structure includes preparing a material and making the earmuff using the material, as follows:

[0069] S1. Take an appropriate amount of nano powder, add it to liquid, and stir to obtain a mixed solution, wherein the content of nano powder in the mixed solution is 0.2 mol / L.

[0070] S2. The mixed solution is heated to 40° C. and subjected to ultrasonic vibration for 3 h to ensure that the nanopowder in the solution is evenly dispersed, thereby obtaining a dispersion.

[0071] S3. Place the porous material in the dispersion solution immersed in a vacuum box, and evacuate the mixture until bubbles begin to appear; then stop evacuating the mixture, vibrate the vacuum box, and exhaust the gas in the porous material until no bubbles are generated.

[0072] S4. Take out the porous material that has fully absorbed the dispersion and dry it at a temperature of 60°C. If ordinary circulating air drying equipment is used for drying, the drying time is 24-36 hours. If microwave drying equipment is used for drying, the drying time is 0.5-10 hours. In Example 1 of the present application, drying with ordinary circulating air drying equipment is used as an example, and the drying time is 36 hours.

[0073] S5. Repeat steps S3 and S4 3-8 times until the nano powder content in the porous material reaches 500-1000 mol / m 3 The specific number of repetitions is adjusted according to actual conditions.

[0074] S6. According to the shape of the earmuff shell, the porous material obtained in S5 is polished and formed to obtain the earmuff liner.

[0075] S7. Apply sealing paint between the earmuff shell and the earmuff liner, and fix the earmuff liner and the earmuff shell to obtain the hearing protection earmuff.

[0076] Performance testing

[0077] In order to further study the effects of various components and preparation parameters on performance, the present application further conducted the following experiments.

[0078] Noise reduction test

[0079]

[0080] The wear resistance test data of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1, wherein the average values ​​are all arithmetic mean values.

[0081] Table 1 Noise reduction performance test data table

[0082]

[0083] From the analysis of Table 1, it can be seen that the average noise reduction value of Example 1 in the full frequency band (63-8kHz) can reach 32.9dB; at low frequency (63-1kHz), the noise reduction value can reach 28.7dB; at medium and high frequency (315-8kHz), the noise reduction value can reach 36.7dB, all of which are higher than the noise reduction standard of ordinary noise reduction earmuffs. The existing ordinary active noise reduction requirement at low frequency (63-1kHz) is not less than 20 decibels. The hearing protection earmuffs made of nanoporous structure materials can effectively reduce low frequency noise without using any active noise reduction electronic components, and achieve the effect of active noise reduction. Comparing Example 1 with Comparative Example 2, after the cavity is dug out, the noise reduction value is significantly improved.

[0084] Comparing Example 1 with Example 2, the average noise reduction value of each frequency band of the two embodiments is 32.89dB, indicating that there is no significant difference in the overall noise reduction performance of the two processes, but the two have their own advantages in different frequency bands. Example 1 performs more prominently in the low frequency band, especially the noise reduction value at low frequencies such as 63Hz and 125Hz is significantly better than that of Example 2. This is due to the high efficiency of alcohol as a dispersion medium, which makes the nanopowder more evenly distributed, thus performing better in low-frequency steady-state noise scenarios and more suitable for the actual needs of factories.

[0085] Example 2 performs relatively well in the mid-to-high frequency bands, which may be due to the denser internal pore structure of the material under the pure water process, which can more effectively scatter and absorb mid-to-high frequency transient noise.

[0086] Sensitization test

[0087]

[0088]

[0089] The results of the sensitization test of Example 1 are shown in Table 2.

[0090] Table 2 Sensitization test data table

[0091]

[0092]

[0093] It can be seen from Table 2 that the nano-bionic noise reduction hearing protection earmuff material prepared in the present application is non-allergenic and can be used in various wearable protective equipment.

[0094] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a hearing protection earmuff material based on a nanoporous structure, characterized in that: The following steps are involved: S1, dispersing nano powder in liquid to form a mixed liquid; S2, heating the mixed solution to 30-50° C., and dispersing by ultrasonic vibration to obtain a dispersion; S3, placing the porous material in a vacuum box, soaking it in the dispersion, and evacuating the dispersion until bubbles appear; then stopping the evacuation, and oscillating to expel the remaining gas in the porous material; S4, taking out the porous material that absorbed the mixed solution in S3, and drying it at 50-80°C; S5, repeating steps S3 and S4 for several times until the nano powder content in the porous material obtained after drying reaches 500-1000 mol / m 3 .

2. The method for preparing a hearing protection earmuff material based on a nanoporous structure according to claim 1, characterized in that: In S1, the nano powder is any one of graphene oxide, carbon nanotubes, and boron nitride, and the content of the nano powder in the mixed solution is 0.15-0.3 mol / L.

3. The method for preparing a hearing protection earmuff material based on a nanoporous structure according to claim 1, characterized in that: In S1, the liquid is a mixed solution of pure water and alcohol, and the alcohol content is 5-30% vol.

4. The method for preparing a hearing protection earmuff material based on a nanoporous structure according to claim 1, characterized in that: In S3, the porous material is a polymer foam material, specifically any one of polyurethane sponge, melamine sponge, and polyester fiber.

5. The method for preparing a hearing protection earmuff material based on a nanoporous structure according to claim 1, characterized in that: In S5, steps S3 and S4 are repeated 3-8 times.

6. An application of a hearing protection earmuff material based on a nanoporous structure, characterized in that: The method for preparing hearing protection earmuffs specifically comprises the following steps: A1. According to the shape of the earmuff shell, the porous material obtained in S5 is polished and shaped to obtain the earmuff liner; A2. Grinding the cavity on the earmuff inner shell side; A3, fixing the earmuff inner liner after grinding the cavity to the earmuff shell to obtain the protective earmuff.

7. The use of a hearing protection earmuff material based on a nanoporous structure according to claim 6, characterized in that: In A3, after polishing, the cavity is semi-ellipsoidal, and the distance from the deepest part of the cavity to the ear is not less than 2 cm.

8. The use of a hearing protection earmuff material based on a nanoporous structure according to claim 6, characterized in that: In A3, a sealing coating having flexibility and elasticity is applied between the earmuff shell and the earmuff liner to fix the earmuff liner and the earmuff shell.

9. The use of a hearing protection earmuff material based on a nanoporous structure according to claim 8, characterized in that: The sealing coating is any one of silicone grease, fluoro grease and vaseline.

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