Sound-absorbing metal plate as well as preparation method and application thereof

Abstract

The invention relates to the technical field of functional materials, in particular to a sound-absorbing metal plate and a preparation method and application thereof. According to the sound-absorbing metal plate provided by the invention, the metal panel, the functional inner core and the back plate are adopted, and the core is that the sound-absorbing structure of the functional inner core is utilized, so that the noise reduction coefficient is more than 0.95. Specifically, according to the sound-absorbing metal plate provided by the invention, ethylene-vinyl acetate and polyethylene glycol terephthalate are adopted as basic resin, and the pore structure of the functional inner core is controlled by utilizing the synergistic effect of the foaming agent and the cross-linking agent, so that the pore structure is more beneficial to efficient absorption and reduction of sound reflection. According to the sound-absorbing metal plate, the functional inner core is further arranged between the metal face plate and the back plate, the sound-absorbing function and the structural stability of the functional inner core are further enhanced, and the sound-absorbing metal plate provided by the invention achieves the optimal performance. The sound-absorbing metal plate provided by the invention has the advantages of favorable flame retardancy, favorable safety, decoration and beautification functions and favorable overall effect.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, and in particular to a sound-absorbing metal plate, its preparation method, and its application. Background Technology

[0002] Sound-absorbing metal panels, as the core component of metal sound barriers, are widely used in industrial equipment, high-speed railways, and rail transportation. A sound-absorbing metal panel typically consists of three parts: a metal panel (such as an aluminum or galvanized steel plate), a cavity, and a back panel. The metal panel generally features structures such as round holes, micro-perforations, or louvers, while the cavity is filled with sound-absorbing materials such as rock wool or glass wool. Some sound-absorbing metal panels can achieve sound attenuation through air resonance using specific micro-perforated structures, eliminating the need for filling the cavity.

[0003] Currently, the noise reduction coefficient of commercially available sound-absorbing metal panels is generally above 0.7, while some high-performance sound-absorbing metal panels have a noise reduction coefficient above 0.85. For example, micro-perforated aluminum panels can achieve a sound absorption performance with a noise reduction coefficient of 1.0, and composite sound-absorbing metal panels (such as perforated sound-absorbing panels or louvered sound-absorbing panels) have a noise reduction coefficient of 0.84 to 0.95.

[0004] In summary, how to obtain a sound-absorbing metal plate with a better noise reduction coefficient without using a micro-perforated structure is a common problem faced by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a sound-absorbing metal plate, its preparation method and application. The sound-absorbing metal plate provided by the present invention has a noise reduction coefficient of more than 0.95 and its sound absorption performance is significantly improved.

[0006] This invention provides a sound-absorbing metal plate, comprising a functional core and metal panels and a back panel respectively covering both sides of the functional core; the functional core comprises the following components in parts by weight: 20-40 parts ethylene-vinyl acetate, 60-80 parts polyethylene terephthalate, 0.5-3.2 parts foaming agent, 2.8-4.5 parts sodium dodecyl sulfate, 0.1-0.5 parts crosslinking agent, 6-8 parts lubricant, and 6-12 parts flame retardant; the pore structure of the functional core includes a semi-through-hole structure, a through-hole structure, and a closed-hole structure; the semi-through-hole structure accounts for not less than 70% of the volume of the pore structure; the inner diameter of the pore structure of the functional core is 10-40 nanometers.

[0007] Preferably, the surface of the metal panel is provided with a circular hole; the diameter of the circular hole is 12~35 nanometers.

[0008] Preferably, the thickness of the functional core is 3 cm or more.

[0009] Preferably, the foaming agent comprises a sulfonyl hydrazine foaming agent and a nitrosyl foaming agent; the sulfonyl hydrazine foaming agent comprises one or more of p-toluenesulfonyl hydrazine and 4,4'-oxobisbenzenesulfonyl hydrazine; the nitrosyl foaming agent comprises N,N'-dinitrospentamethylenetetramine; and the mass ratio of the sulfonyl hydrazine foaming agent to the nitrosyl foaming agent is 1~1.5:1.

[0010] Preferably, the crosslinking agent includes one or more of organic peroxide crosslinking agents, acid anhydride crosslinking agents, and isocyanurate crosslinking agents; the organic peroxide crosslinking agent includes one or more of dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-ditert-butylperoxide; the acid anhydride crosslinking agent is phthalic anhydride; and the isocyanurate crosslinking agent is triallyl isocyanurate.

[0011] Preferably, the lubricant comprises one or more of stearic acid and calcium stearate.

[0012] Preferably, the semi-through hole structure occupies 70-86% of the volume of the hole structure; the closed hole structure occupies no more than 5% of the volume of the hole structure.

[0013] The present invention also provides a method for preparing the sound-absorbing metal plate described above, comprising the following steps: (1) Ethylene-vinyl acetate, polyethylene terephthalate, foaming agent, sodium dodecyl sulfate, crosslinking agent, lubricant and flame retardant are mixed and molded to obtain a functional inner core; (2) A metal panel or back plate is glued to both sides of the functional core to obtain the sound-absorbing metal plate.

[0014] Preferably, the compression molding includes a first stage and a second stage performed sequentially; the temperature of the first stage is 150~180 degrees Celsius, and the holding time is 5~20 minutes; the temperature of the second stage is 200~240 degrees Celsius, and the holding time is 10~20 minutes; the pressure of the compression molding is 5~20 MPa.

[0015] The present invention also provides the application of the sound-absorbing metal plate described in the above-described scheme or the sound-absorbing metal plate prepared by the above-described scheme in the fields of industrial noise reduction, transportation, or construction.

[0016] This invention provides a sound-absorbing metal panel. The sound-absorbing metal panel of this invention, by employing a metal panel, a functional core, and a back panel, achieves a noise reduction coefficient of over 0.95 by utilizing the sound-absorbing structure of the functional core. Specifically, the sound-absorbing metal panel of this invention uses ethylene-vinyl acetate and polyethylene terephthalate as base resins, and utilizes the synergistic effect of foaming agents and crosslinking agents to control the pore structure of the functional core, making its pore structure more conducive to efficient absorption and reducing sound reflection. Furthermore, this invention places the functional core in the middle of the metal panel and back panel, further enhancing the sound absorption function and structural stability of the functional core, enabling the sound-absorbing metal panel of this invention to achieve optimal performance. The sound-absorbing metal panel of this invention has good flame retardant properties, good safety, decorative and aesthetic functions, and a good overall effect.

[0017] This invention also provides a method for preparing the sound-absorbing metal plate described above. The preparation method provided by this invention has simple steps, is easy to operate, uses readily available raw materials, and has the potential for industrial-scale application.

[0018] This invention also provides applications of the sound-absorbing metal plate described in the above-described scheme or the sound-absorbing metal plate prepared by the above-described scheme in industrial noise reduction, transportation, or construction fields. The sound-absorbing metal plate provided by this invention has good sound absorption performance, a noise reduction coefficient of over 0.95, and is easy to install and has a long service life, making it suitable for sound absorption and noise reduction in industrial, transportation, or construction fields. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the sound-absorbing metal plate provided by the present invention; Attached diagram labels: 1 for metal panel, 2 for functional core, 3 for back panel, 4 for hole structure. Detailed Implementation

[0021] This invention provides a sound-absorbing metal plate, comprising a functional core and metal panels and a back panel respectively covering both sides of the functional core; the functional core comprises the following components in parts by weight: 20-40 parts ethylene-vinyl acetate, 60-80 parts polyethylene terephthalate, 0.5-3.2 parts foaming agent, 2.8-4.5 parts sodium dodecyl sulfate, 0.1-0.5 parts crosslinking agent, 6-8 parts lubricant, and 6-12 parts flame retardant; the pore structure of the functional core includes a semi-through-hole structure, a through-hole structure, and a closed-hole structure; the semi-through-hole structure accounts for not less than 70% of the volume of the pore structure; the inner diameter of the pore structure of the functional core is 10-40 nanometers.

[0022] The sound-absorbing metal plate provided by this invention includes a metal panel; the surface of the metal panel preferably has circular holes; the diameter of the circular holes is preferably 12-35 nanometers; the metal panel is preferably an aluminum plate or a galvanized steel plate. This invention uses circular holes of the above-mentioned size, allowing the metal panel and the functional core to better fit together, resulting in better sound absorption performance.

[0023] The sound-absorbing metal plate provided by the present invention includes a back plate; the back plate is preferably an aluminum plate or a galvanized steel plate.

[0024] The sound-absorbing metal plate provided by this invention includes a functional inner core; the thickness of the functional inner core is preferably 3 cm or more, more preferably 5-30 cm. The use of a functional inner core of the above dimensions in this invention helps to better utilize the structure of the functional inner core and ensures better sound absorption performance.

[0025] In this invention, the functional core preferably comprises the following components in parts by weight: 25-35 parts ethylene-vinyl acetate, 65-75 parts polyethylene terephthalate, 1-2.5 parts foaming agent, 3-4 parts sodium dodecyl sulfate, 0.3-0.4 parts crosslinking agent, 7 parts lubricant, and 8-10 parts flame retardant.

[0026] In this invention, the foaming agent preferably includes sulfonyl hydrazine foaming agents and nitrosyl foaming agents; the sulfonyl hydrazine foaming agent preferably includes one or more of p-toluenesulfonyl hydrazine and 4,4'-oxobisbenzenesulfonyl hydrazine; the nitrosyl foaming agent preferably includes N,N'-dinitrospentamethylenetetramine; the mass ratio of the sulfonyl hydrazine foaming agent to the nitrosyl foaming agent is preferably 1~1.5:1, more preferably 1.2:1.

[0027] In this invention, the crosslinking agent preferably includes one or more of organic peroxide crosslinking agents, acid anhydride crosslinking agents, and isocyanurate crosslinking agents; the organic peroxide crosslinking agent preferably includes one or more of dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-ditert-butylperoxide; the acid anhydride crosslinking agent is preferably phthalic anhydride; and the isocyanurate crosslinking agent is preferably triallyl isocyanurate. By employing the above-mentioned foaming agent and crosslinking agent, this invention enables the functional core to obtain a sufficient pore structure, especially a semi-through-pore structure, while ensuring the strength and toughness of the functional core, maintaining its pore structure without significant deformation, ensuring the stability of the pore structure, and providing effective support for the metal panel and backplate.

[0028] In this invention, the lubricant preferably includes one or more of stearic acid and calcium stearate. By adding a lubricant, this invention ensures the uniformity of the mixing of all components and improves the uniformity of the pore structure of the functional core.

[0029] In this invention, the flame retardant preferably includes one or more of magnesium hydroxide and aluminum hydroxide. By adding a flame retardant, this invention improves the flame-retardant performance of the functional core, ensuring its safety during use.

[0030] In this invention, the volume ratio of the semi-through hole structure to the hole structure is preferably 70-86%, more preferably 75-80%; the volume ratio of the closed hole structure to the hole structure is preferably not higher than 5%, more preferably 1-3%.

[0031] In this invention, the inner diameter of the hole structure of the functional core is preferably 12-35 nanometers.

[0032] In this invention, the porosity of the functional core is preferably 75-85%, more preferably 81-83%.

[0033] The structure of the sound-absorbing metal plate provided by this invention is as follows: Figure 1 As shown, the sound-absorbing metal plate of this invention includes a functional inner core and metal face plates and back plates covering both sides of the functional inner core. The functional inner core contains a rich porous structure, mainly semi-through-hole structures. These pores are densely packed and irregularly shaped, with pore sizes concentrated in the range of 10-40 nanometers, forming a good sound-absorbing structure. The functional inner core, together with the metal face plates and back plates, forms a sound-absorbing metal plate with excellent sound absorption performance.

[0034] The present invention also provides a method for preparing the sound-absorbing metal plate described above, comprising the following steps: (1) Ethylene-vinyl acetate, polyethylene terephthalate, foaming agent, sodium dodecyl sulfate, crosslinking agent, lubricant and flame retardant are mixed and molded to obtain a functional inner core; (2) A metal panel or back plate is glued to both sides of the functional core to obtain the sound-absorbing metal plate.

[0035] This invention involves mixing ethylene-vinyl acetate, polyethylene terephthalate, a foaming agent, sodium dodecyl sulfate, a crosslinking agent, a lubricant, and a flame retardant, and then molding them to obtain a functional inner core. In this invention, the mixing is preferably performed by stirring; the stirring speed is preferably 400-600 rpm, more preferably 450-500 rpm; and the mixing time is preferably 20-40 minutes, more preferably 25-35 minutes.

[0036] In this invention, the compression molding preferably includes a first stage and a second stage performed sequentially; the temperature of the first stage is preferably 150-180 degrees Celsius, more preferably 165-179 degrees Celsius, and the holding time is preferably 5-20 minutes, more preferably 10-15 minutes; the temperature of the second stage is preferably 200-240 degrees Celsius, more preferably 220-230 degrees Celsius, and the holding time is preferably 10-20 minutes, more preferably 15-18 minutes; the compression molding pressure is preferably 5-20 MPa, more preferably 10-15 MPa. This invention, through compression molding under the above conditions, helps to obtain the target hole structure in the functional core.

[0037] In this invention, the post-molding process preferably includes demolding, product trimming, and cleaning. Through these post-processing steps, the present invention removes impurities from the surface of the functional core, ensuring its proper functioning.

[0038] After obtaining the functional core, the present invention bonds a metal panel or a back plate to both sides of the functional core to obtain the sound-absorbing metal plate. In the present invention, the bonding preferably includes the following steps: applying adhesive to the surface of the metal panel or back plate, and then pressing the metal panel and back plate to the functional core.

[0039] In this invention, the coating is preferably applied by roller coating or spray coating; the thickness of the coating is preferably no more than 1 mm, and more preferably 0.4 to 0.8 mm.

[0040] This invention does not have special requirements regarding the type of adhesive used for bonding, as long as it can stably connect the functional core to the metal panel and back plate. In a specific embodiment of this invention, isocyanate (PU) adhesive is used to bond the interface between the metal panel and the functional core, as well as the interface between the back plate and the functional core.

[0041] In this invention, the pressing pressure is preferably 5~10 kg / m 2 More preferably 7~8 kg / m 2 The pressure holding time is preferably 15-60 minutes, more preferably 25-45 minutes, and even more preferably 35 minutes. Through the above-described bonding operation, this invention ensures the overall structural stability of the sound-absorbing metal plate and guarantees the effective cooperation between the metal panel and the functional core in terms of sound absorption.

[0042] The present invention also provides the application of the sound-absorbing metal plate described in the above-described scheme or the sound-absorbing metal plate prepared by the above-described scheme in the fields of industrial noise reduction, transportation, or construction.

[0043] The sound-absorbing metal plate provided by this invention has good sound absorption performance, with a noise reduction coefficient of over 0.95. It is also easy to install, has a long service life, and is suitable for sound absorption and noise reduction in industrial, transportation, or building fields. It is both aesthetically pleasing and practical.

[0044] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 18 nanometers in diameter on its surface; the back plate is a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 70% of the volume of the hole structure and the closed hole structure accounting for 5% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed between 12 and 35 nanometers, and the thickness of the functional core is 5 centimeters.

[0046] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 20 kg of ethylene-vinyl acetate, 80 kg of polyethylene terephthalate, 0.5 kg of foaming agent (p-toluenesulfonyl hydrazine and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.2:1), 4.5 kg of sodium dodecyl sulfate, 0.1 kg of dicumyl peroxide, 6 kg of stearic acid and 6 kg of magnesium hydroxide at 400 rpm for 40 minutes. First, keep warm at 150 degrees Celsius for 20 minutes, and then keep warm at 200 degrees Celsius for 20 minutes. The pressure of molding is controlled at 15 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0047] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.4 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 5 kg / m². 2 The pressure was maintained for 35 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0048] Example 2 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 20 nanometers in diameter on its surface; the back plate is a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 75% of the volume of the hole structure and the closed hole structure accounting for 4% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed in the range of 12~40 nanometers; the thickness of the functional core is 30 centimeters.

[0049] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 40 kg of ethylene-vinyl acetate, 60 kg of polyethylene terephthalate, 3.2 kg of foaming agent (4,4'-oxobis(benzenesulfonyl hydrazine) and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.5:1), 4.5 kg of sodium dodecyl sulfate, 0.5 kg of phthalic anhydride, 8 kg of calcium stearate and 12 kg of aluminum hydroxide at 600 rpm for 20 minutes. First, keep warm at 150 degrees Celsius for 20 minutes, and then keep warm at 200 degrees Celsius for 10 minutes. The pressure of molding is controlled at 10 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0050] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.8 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 10 kg / m². 2 The pressure was maintained for 45 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0051] Example 3 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 35 nanometers in diameter on its surface; the back plate is an aluminum plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 80% of the volume of the hole structure and the closed hole structure accounting for 3% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed in the range of 10~40 nanometers; the thickness of the functional core is 15 centimeters.

[0052] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 30 kg of ethylene-vinyl acetate, 70 kg of polyethylene terephthalate, 2.5 kg of foaming agent (1:1 mass ratio of p-toluenesulfonyl hydrazine and N,N'-dinitrospentamethylenetetramine), 3.5 kg of sodium dodecyl sulfate, 0.3 kg of triallyl isocyanurate, 7.5 kg of calcium stearate and 8 kg of magnesium hydroxide at 450 rpm for 25 minutes. First, keep warm at 165 degrees Celsius for 15 minutes, and then keep warm at 220 degrees Celsius for 15 minutes. The molding pressure is controlled at 15 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0053] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 1 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 7 kg / m². 2 The pressure is maintained for 60 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0054] Example 4 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is an aluminum plate with circular holes of 35 nanometers in diameter on its surface; the back plate is a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 86% of the volume of the hole structure and the closed hole structure accounting for 1% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed in the range of 10~35 nanometers; the thickness of the functional core is 3 centimeters.

[0055] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 35 kg of ethylene-vinyl acetate, 65 kg of polyethylene terephthalate, 1.5 kg of foaming agent (4,4'-oxobis(benzenesulfonyl hydrazine) and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.1:1), 2.8 kg of sodium dodecyl sulfate, 0.2 kg of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 6.5 kg of stearic acid and 11 kg of aluminum hydroxide at 500 rpm for 40 minutes. First, keep warm at 155 degrees Celsius for 15 minutes, and then keep warm at 230 degrees Celsius for 18 minutes. The molding pressure is controlled at 10 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0056] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.5 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 8 kg / m². 2 The pressure is maintained for 25 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0057] Example 5 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 12 nanometers in diameter on its surface; the back plate is an aluminum plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 74% of the volume of the hole structure and the closed hole structure accounting for 2% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed between 12 and 25 nanometers; the thickness of the functional core is 25 centimeters.

[0058] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 35 kg of ethylene-vinyl acetate, 75 kg of polyethylene terephthalate, 2 kg of foaming agent (p-toluenesulfonyl hydrazine and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.4:1), 3 kg of sodium dodecyl sulfate, 0.1~0.5 kg of triallyl isocyanurate, 8 kg of calcium stearate and 12 kg of magnesium hydroxide at 500 rpm for 35 minutes. First, keep warm at 165°C for 15 minutes, and then keep warm at 220°C for 15 minutes. The pressure of molding is controlled at 10 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0059] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.8 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 7 kg / m². 2 The pressure was maintained for 35 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0060] Example 6 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is an aluminum plate with circular holes of 20 nanometers in diameter on its surface; the back plate is a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 81% of the volume of the hole structure and the closed hole structure accounting for 3% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed between 15 and 28 nanometers; the thickness of the functional core is 20 centimeters.

[0061] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 30 kg of ethylene-vinyl acetate, 70 kg of polyethylene terephthalate, 2.2 kg of foaming agent (p-toluenesulfonyl hydrazine and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.2:1), 3.5 kg of sodium dodecyl sulfate, 0.1 kg of 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 7.5 kg of stearic acid and 12 kg of magnesium hydroxide at 500 rpm for 35 minutes. First, keep warm at 168 degrees Celsius for 15 minutes, and then keep warm at 230 degrees Celsius for 18 minutes. The molding pressure is controlled at 15 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0062] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.7 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 10 kg / m². 2 The pressure is maintained for 15 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0063] Example 7 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 24 nanometers in diameter on its surface; the back plate is an aluminum plate or a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 72% of the volume of the hole structure and the closed hole structure accounting for 3% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed in the range of 12~37 nanometers; the thickness of the functional core is 8 centimeters.

[0064] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 20 kg of ethylene-vinyl acetate, 80 kg of polyethylene terephthalate, 3.2 kg of foaming agent (4,4'-oxobis(benzenesulfonyl hydrazine) and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.2:1), 4.5 kg of sodium dodecyl sulfate, 0.4 kg of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 6.5 kg of calcium stearate and 9 kg of magnesium hydroxide at 450 rpm for 25 minutes. First, keep warm at 180 degrees Celsius for 20 minutes, and then keep warm at 240 degrees Celsius for 15 minutes. The molding pressure is controlled at 12 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0065] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.8 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 8 kg / m². 2 The pressure was maintained for 35 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0066] Example 8 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is an aluminum plate with circular holes of 30 nanometers in diameter on its surface; the back plate is an aluminum plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 75% of the volume of the hole structure and the closed hole structure accounting for 2% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed in the range of 15~35 nanometers; the thickness of the functional core is 12 centimeters.

[0067] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 37 kg of ethylene-vinyl acetate, 63 kg of polyethylene terephthalate, 3.2 kg of foaming agent (4,4'-oxobis(benzenesulfonyl hydrazine) and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.2:1), 4.5 kg of sodium dodecyl sulfate, 0.5 kg of dicumyl peroxide, 8 kg of calcium stearate and 10 kg of magnesium hydroxide at 500 rpm for 35 minutes. First, keep warm at 170 degrees Celsius for 15 minutes, and then keep warm at 230 degrees Celsius for 15 minutes. The molding pressure is controlled at 17 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0068] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.8 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 7 kg / m². 2 The pressure was maintained for 45 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0069] Example 9 This embodiment prepares a sound-absorbing metal plate, including a functional core, a metal panel covering one side of the functional core, and a back plate covering the other side of the functional core; the metal panel is a galvanized steel plate with circular holes of 18 nanometers in diameter on its surface; the back plate is a galvanized steel plate; the hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure, with the semi-through hole structure accounting for 84% of the volume of the hole structure and the closed hole structure accounting for 1% of the volume of the hole structure; the inner diameter of the hole structure of the functional core is distributed between 16 and 38 nanometers; the thickness of the functional core is 23 centimeters.

[0070] The specific steps for preparing the sound-absorbing metal plate in this embodiment are as follows: (1) Mix 20 kg of ethylene-vinyl acetate, 80 kg of polyethylene terephthalate, 2 kg of foaming agent (4,4'-oxobis(benzenesulfonyl hydrazine) and N,N'-dinitrospentamethylenetetramine in a mass ratio of 1.2:1), 3 kg of sodium dodecyl sulfate, 0.5 kg of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 8 kg of calcium stearate and 9 kg of magnesium hydroxide at 500 rpm for 35 minutes. First, keep warm at 180 degrees Celsius for 10 minutes, and then keep warm at 240 degrees Celsius for 20 minutes. The molding pressure is controlled at 15 MPa throughout the process. Demold, trim and clean the product to obtain the functional core.

[0071] (2) Apply isocyanate adhesive to the surfaces of the metal panel and back panel using a roller, with a thickness of 0.9 mm for both. Then, press the metal panel and back panel to the functional core at a pressure of 8 kg / m². 2 The pressure was maintained for 35 minutes to obtain the sound-absorbing metal plate of this embodiment.

[0072] Comparative Example 1 The preparation method of this comparative example is the same as that of Example 1, except that ethylene-vinyl acetate is replaced with an equal amount of polyethylene terephthalate.

[0073] Comparative Example 2 The preparation method of this comparative example is the same as that of Example 1, except that polyethylene terephthalate is replaced with an equal amount of ethylene-vinyl acetate.

[0074] Comparative Example 3 The preparation method of this comparative example is the same as that of Example 1, except that no crosslinking agent is added.

[0075] Comparative Example 4 The preparation method of this comparative example is the same as that of Example 1, except that no foaming agent was added.

[0076] Comparative Example 5 The preparation method of this comparative example is the same as that of Example 1, except that the 20-minute incubation at 150 degrees Celsius is omitted, and the incubation at 200 degrees Celsius is directly performed for 20 minutes.

[0077] Test Example 1 The sound absorption performance of the sound-absorbing metal plates prepared in Examples 1-9 and Comparative Examples 1-5 was tested using the reverberation chamber method. The test method was in accordance with GB / T 20247 standard. The sound absorption coefficients at four frequencies of 250Hz, 500Hz, 1000Hz and 2000Hz were measured, and the arithmetic mean was taken as the noise reduction coefficient. The results are shown in Table 1.

[0078] Table 1 Performance tests of Examples 1-9 and Comparative Examples 1-5

[0079] As shown in Table 1, the sound-absorbing metal plate provided by this invention has a noise reduction coefficient of over 0.95, which is significantly better than that of comparative examples 1-5. Therefore, this invention successfully prepares a high-performance sound-absorbing metal plate by using a combination of specific resins, foaming agents, and crosslinking agents, along with specific process parameters, providing a new option for sound absorption and noise reduction in industrial and transportation sectors.

[0080] The embodiments of the present invention have been described above; however, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A sound-absorbing metal plate, characterized in that, It includes a functional core and metal panels and a back plate respectively covering both sides of the functional core; The functional core comprises the following components in parts by weight: 20-40 parts ethylene-vinyl acetate, 60-80 parts polyethylene terephthalate, 0.5-3.2 parts foaming agent, 2.8-4.5 parts sodium dodecyl sulfate, 0.1-0.5 parts crosslinking agent, 6-8 parts lubricant, and 6-12 parts flame retardant; The hole structure of the functional core includes a semi-through hole structure, a through hole structure, and a closed hole structure. The semi-through hole structure accounts for no less than 70% of the volume of the hole structure; The inner diameter of the pore structure of the functional core is 10~40 nanometers.

2. The sound-absorbing metal plate according to claim 1, characterized in that, The surface of the metal panel is provided with circular holes; The diameter of the circular hole is 12-35 nanometers.

3. The sound-absorbing metal plate according to claim 1, characterized in that, The thickness of the functional core is more than 3 centimeters.

4. The sound-absorbing metal plate according to claim 1, characterized in that, The foaming agent includes sulfonyl hydrazine foaming agents and nitrosyl foaming agents; The sulfonyl hydrazine foaming agent includes one or more of p-toluenesulfonyl hydrazine and 4,4'-oxobisbenzenesulfonyl hydrazine; The nitrosyl-based foaming agent includes N,N'-dinitrospentamethylenetetramine; The mass ratio of the sulfonyl hydrazine foaming agent to the nitrosyl foaming agent is 1~1.5:

1.

5. The sound-absorbing metal plate according to claim 1 or 4, characterized in that, The crosslinking agent includes one or more of organic peroxide crosslinking agents, acid anhydride crosslinking agents, and isocyanurate crosslinking agents; The organic peroxide crosslinking agent includes one or more of dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-ditert-butylperoxyhexane. The acid anhydride crosslinking agent is phthalic anhydride; The isocyanurate crosslinking agent is triallyl isocyanurate.

6. The sound-absorbing metal plate according to claim 1, characterized in that, The lubricant includes one or more of stearic acid and calcium stearate.

7. The sound-absorbing metal plate according to claim 1, characterized in that, The semi-through hole structure accounts for 70-86% of the volume of the hole structure; The closed-hole structure occupies no more than 5% of the volume of the hole structure.

8. A method for preparing the sound-absorbing metal plate according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Ethylene-vinyl acetate, polyethylene terephthalate, foaming agent, sodium dodecyl sulfate, crosslinking agent, lubricant and flame retardant are mixed and molded to obtain a functional inner core; (2) A metal panel or back plate is glued to both sides of the functional core to obtain the sound-absorbing metal plate.

9. The preparation method according to claim 8, characterized in that, The compression molding process includes a first stage and a second stage performed sequentially. The temperature of the first stage is 150~180 degrees Celsius, and the holding time is 5~20 minutes; The temperature in the second stage is 200-240 degrees Celsius, and the holding time is 10-20 minutes; The pressure for compression molding is 5~20MPa.

10. The application of the sound-absorbing metal plate according to any one of claims 1 to 7 or the sound-absorbing metal plate obtained by the preparation method according to any one of claims 8 to 9 in the fields of industrial noise reduction, transportation, or construction.

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