Low-frequency high-sound-absorption-efficiency sound-absorption cotton for electric vehicles and manufacturing method thereof

Abstract

The application relates to low-frequency high-sound-absorption-efficiency sound-absorption cotton for electric vehicles and a manufacturing method thereof. The sound-absorption cotton comprises, from top to bottom, a non-woven fabric, a film layer and a sound-absorption layer; the material of the film layer is PE, and the total thickness of the non-woven fabric and the film layer is 0.1-0.3 mm. The manufacturing method comprises the following steps: S1, manufacturing the sound-absorption layer; S2, laying and forming; and S3, composite forming. Compared with the prior art, the application has high sound-absorption efficiency for low-frequency noise of electric vehicles, simple preparation mode, saves a large number of complex processes and reduces production cost.

Description

Technical Field

[0001] This invention belongs to the field of sound-absorbing cotton technology, and in particular relates to a low-frequency, high-sound-absorbing cotton for electric vehicles and its manufacturing method. Background Technology

[0002] With the increasing emphasis on environmental protection, electric vehicles are receiving more and more attention. Compared to traditional cars, electric vehicles are more environmentally friendly, energy-efficient, and cleaner. Compared to the engine noise of traditional cars, the noise of electric vehicles comes from the motor, tires, and wind noise. Electric vehicles use an electric drive system to propel the vehicle, and compared to the internal combustion engine of traditional cars, the noise of the electric drive system is much lower. While high-frequency noise attenuates rapidly with distance or obstacles, low-frequency noise does not attenuate easily and reaches our ear bones directly, causing continuous disturbance. Prolonged exposure to low-frequency noise can easily lead to nervous tension, rapid heart rate, high blood pressure, irritability, and even, in severe cases, neurasthenia, insomnia, and headaches.

[0003] The PET sound-absorbing cotton commonly used in electric vehicles has low sound absorption efficiency at low frequencies, with the commonly used 450g / m³... 2 Taking PET sound-absorbing cotton as an example, the target line with higher requirements is as follows: for example, the sound-absorbing cotton used by Audi has a measured sound absorption efficiency of 0.20, 0.30, 0.40, 0.50 and 0.60 in the range of 400-1000HZ, which is not high. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a low-frequency, high-sound-absorbing cotton for electric vehicles and its manufacturing method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] The first aspect of the present invention provides a low-frequency high sound absorption cotton for electric vehicles, characterized in that it comprises a non-woven fabric, a coating layer, and a sound absorption layer arranged sequentially from top to bottom;

[0007] The coating layer is made of PE, and the total thickness of the nonwoven fabric and the coating layer is 0.1-0.3 mm.

[0008] In a preferred embodiment of the present invention, the total thickness of the nonwoven fabric and the coating layer is 0.2 mm.

[0009] Furthermore, the nonwoven fabric is made of one or more of PP, PET, PA, HDPE, and PVC.

[0010] In a preferred embodiment of the present invention, the nonwoven fabric is made of PP.

[0011] Furthermore, the sound-absorbing layer is made of one or more of PET, LPET, PP, PA, and PLA.

[0012] In a preferred embodiment of the present invention, the sound-absorbing layer is made of PET.

[0013] Furthermore, the basis weight of the nonwoven fabric is 50-100 g / m². 2 .

[0014] In a preferred embodiment of the present invention, the nonwoven fabric has a basis weight of 80 g / m². 2 .

[0015] Furthermore, the basis weight of the coating layer is 20-50 g / m³. 2 .

[0016] In a preferred embodiment of the present invention, the basis weight of the coating layer is 30 g / m². 2 .

[0017] Furthermore, the basis weight of the sound-absorbing layer is 300-1000 g / m². 2 .

[0018] In a preferred embodiment of the present invention, the basis weight of the sound-absorbing layer is 450-600 g / m². 2 .

[0019] A second aspect of this invention provides a method for manufacturing low-frequency, high-sound-absorbing cotton for electric vehicles, comprising the following steps:

[0020] S1: Making the sound-absorbing layer: Open and mix low-melting-point PET fiber, ultra-fine PET fiber and acrylic fiber in proportion, and then comb them to obtain the sound-absorbing layer;

[0021] S2: Laying and shaping: The sound-absorbing layer after S1 is combed is laid into a mesh, and then PE powder is sprinkled on the PP non-woven fabric with PE coating and the PE coating side is laid with the sound-absorbing layer facing the sound-absorbing layer to obtain the sound-absorbing cotton to be composited.

[0022] S3: Composite molding: The sound-absorbing cotton to be composited in S2 is transported to the drying room for heating and molding.

[0023] Furthermore, in S1, the weight ratio of PET low melting point fiber, ultrafine PET fiber and acrylic fiber is (20-25):(50-60):(20-25).

[0024] Furthermore, in S2, the amount of PE powder sprinkled is 12-20 g / m². 2 .

[0025] In a preferred embodiment of the present invention, in step S2, the amount of PE powder sprinkled is 16 g / m².2 .

[0026] Furthermore, in S3, the temperature of the drying chamber is set to 200-300℃.

[0027] In a preferred embodiment of the present invention, the temperature of the drying chamber is set to 250°C in step S3.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The sound-absorbing cotton of the present invention has a multi-layer composite structure and does not use glue for bonding (it uses PE powder and high temperature molding), which can reduce the emission performance of vehicle odor, VOC and other substances.

[0030] (2) The sound-absorbing cotton of the present invention has the advantages of being lightweight and has high sound absorption efficiency for low-frequency noise of electric vehicles.

[0031] (3) The sound-absorbing cotton of the present invention uses a coating layer and non-woven fabric, which also has a certain amount of sound insulation, and can effectively reduce noise.

[0032] (4) The sound-absorbing cotton of the present invention is simple to prepare, saves a lot of complicated processes, and reduces production costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the sound-absorbing cotton of the present invention in Example 1.

[0034] Figure 2 This is a schematic diagram of the method for manufacturing the sound-absorbing cotton of the present invention in Example 3.

[0035] Figure 3 This is a schematic diagram of the sound absorption test results of the Alpha Cabin sound-absorbing cotton of the present invention in Example 1.

[0036] Figure 4 This is a schematic diagram of the sound absorption test results of the Alpha Cabin sound-absorbing cotton of the present invention in Example 2.

[0037] Figure 5 This is a schematic diagram showing the sound absorption test results of Alpha Cabin sound-absorbing cotton in Comparative Examples 1 and 2 of Example 1.

[0038] Numbering on the map:

[0039] 1-Non-woven fabric, 2-Laminated coating layer, 3-Sound-absorbing layer. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0041] Unless otherwise specified in this technical solution, the component model, material name, connection structure, control method, and other features are considered to be common technical features disclosed in the prior art.

[0042] In the description of this invention, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a bolted connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] To achieve high sound absorption efficiency for low-frequency noise while maintaining a simple and low-cost manufacturing process, this invention provides a sound-absorbing cotton with high low-frequency sound absorption efficiency for electric vehicles. The structure of this cotton is described in [link to invention]. Figure 1 As shown, it includes a non-woven fabric 1, a coating layer 2, and a sound-absorbing layer 3 arranged sequentially from top to bottom;

[0045] The coating layer 2 is made of PE, and the total thickness of the nonwoven fabric 1 and the coating layer 2 is 0.1-0.3 mm.

[0046] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the nonwoven fabric 1 is made of one or more of PP, PET, PA, HDPE, and PVC.

[0047] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the sound-absorbing layer 3 is made of one or more of PET, LPET, PP, PA, and PLA.

[0048] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the basis weight of the nonwoven fabric 1 is 50-100 g / m². 2.

[0049] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the basis weight of the coating layer 2 is 20-50 g / m². 2 .

[0050] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the weight of the sound-absorbing layer 3 is 300-1000 g / m². 2 .

[0051] This invention also provides a method for manufacturing low-frequency, high-sound-absorbing cotton for electric vehicles, the flowchart of which is shown below. Figure 2 As shown, it includes the following steps:

[0052] S1: Making the sound-absorbing layer: Open and mix low-melting-point PET fiber, ultra-fine PET fiber and acrylic fiber in proportion, and then comb them to obtain the sound-absorbing layer;

[0053] S2: Laying and shaping: The sound-absorbing layer after S1 is combed is laid into a mesh, and then PE powder is sprinkled on the PP non-woven fabric with PE coating and the PE coating side is laid with the sound-absorbing layer facing the sound-absorbing layer to obtain the sound-absorbing cotton to be composited.

[0054] S3: Composite molding: The sound-absorbing cotton to be composited in S2 is transported to the drying room for heating and molding.

[0055] For some specific implementation methods, please refer to [link / reference]. Figure 2 As shown, in S1, the weight ratio of PET low melting point fiber, ultrafine PET fiber and acrylic fiber is (20-25):(50-60):(20-25).

[0056] For some specific implementation methods, please refer to [link / reference]. Figure 2 As shown, in S2, the amount of PE powder sprinkled is 12-20 g / m². 2 .

[0057] For some specific implementation methods, please refer to [link / reference]. Figure 2 As shown, in S3, the temperature of the drying chamber is set to 200-300℃.

[0058] Each of the above implementation methods can be implemented individually, or in any combination of two or more.

[0059] The above implementation methods will be described in more detail below with reference to specific embodiments.

[0060] Example 1

[0061] This embodiment provides a low-frequency, high-sound-absorbing cotton for electric vehicles; its structure can be found in [reference needed]. Figure 1As shown, it includes a non-woven fabric 1, a coating layer 2, and a sound-absorbing layer 3 arranged sequentially from top to bottom;

[0062] The coating layer is made of PE (grade: D8008), and the total thickness of the nonwoven fabric and the coating layer is 0.2 mm. The sound-absorbing layer 3 has a thickness of 18.8 mm. The nonwoven fabric is made of PP (grade: PP-H1304), and the sound-absorbing layer is made of PET (composed of PET low-melting-point fiber (grade: 4080), ultrafine PET fiber (grade: WKDL-HEI), and acrylic fiber (grade: WKDL-QL) in a weight ratio of 20:60:20). The nonwoven fabric has a basis weight of 80 g / m². 2 The basis weight of the coating layer is 30 g / m³. 2 The weight of the sound-absorbing layer is 450 g / m². 2 .

[0063] Example 2

[0064] This embodiment provides a low-frequency, high-sound-absorbing cotton for electric vehicles; its structure can be found in [reference needed]. Figure 1 As shown, it includes a non-woven fabric 1, a coating layer 2, and a sound-absorbing layer 3 arranged sequentially from top to bottom;

[0065] The coating layer is made of PE, and the total thickness of the nonwoven fabric and the coating layer is 0.2 mm. The sound-absorbing layer 3 has a thickness of 18.8 mm. The nonwoven fabric is made of PP, and the sound-absorbing layer is made of PET (composed of PET low-melting-point fiber, ultrafine PET fiber, and acrylic fiber in a weight ratio of 25:50:25). The nonwoven fabric has a basis weight of 80 g / m². 2 The basis weight of the coating layer is 30 g / m³. 2 The weight of the sound-absorbing layer is 600 g / m². 2 .

[0066] Example 3

[0067] This embodiment provides a method for preparing low-frequency, high-sound-absorbing cotton for electric vehicles according to Example 1. For detailed steps, please refer to [link to example]. Figure 2 As shown, it includes:

[0068] S1: Making the sound-absorbing layer: PET low melting point fiber, ultrafine PET fiber and acrylic fiber are put into the opening machine in a weight ratio of 20:60:20 for opening and mixing evenly. Then, they are sent to the carding machine for carding to obtain the sound-absorbing layer.

[0069] S2: Laying and Shaping: The sound-absorbing layer after S1 is conveyed through the conveyor curtain to the mesh laying curtain for laying. Then, PE powder is sprinkled on the PP non-woven fabric with PE coating (the amount of PE powder sprinkled is 16g / m). 2And lay the PE coating side facing the sound-absorbing layer to obtain the sound-absorbing cotton to be laminated;

[0070] S3: Composite molding: The sound-absorbing cotton to be composited in S2 is transported to a drying room and heated at 250℃ to form the composite.

[0071] Example 4

[0072] This embodiment provides a method for preparing low-frequency, high-sound-absorbing cotton for electric vehicles according to Example 2. For detailed steps, please refer to [link to example]. Figure 2 As shown, it includes:

[0073] S1: Making the sound-absorbing layer: PET low melting point fiber, ultrafine PET fiber and acrylic fiber are put into the opening machine in a weight ratio of 25:50:25 for opening and mixing evenly. Then, they are sent to the carding machine for carding to obtain the sound-absorbing layer.

[0074] S2: Laying and Shaping: The sound-absorbing layer after S1 is combed is conveyed to the mesh laying curtain via a conveyor curtain for mesh laying. Then, PE powder is sprinkled onto the PP non-woven fabric with PE coating using a powder spreading device (the amount of PE powder sprinkled is 16g / m). 2 And lay the PE coating side facing the sound-absorbing layer to obtain the sound-absorbing cotton to be laminated;

[0075] S3: Composite molding: The sound-absorbing cotton to be composited in S2 is transported to a drying room and heated at 250℃ to form the composite.

[0076] Comparative Example 1

[0077] The comparative sample was 450g / m 2 The PET sound-absorbing layer is made by feeding low-melting-point PET fibers and ultra-fine PET fibers into an opening machine in a certain proportion, mixing them evenly, and mixing them evenly in a weight ratio of 20:80. The mixture is then passed through a carding machine and a web-laying machine to obtain the sound-absorbing layer.

[0078] Comparative Example 2

[0079] Compared with Comparative Example 1, it is mostly the same, except for 450g / m 2 The PET sound-absorbing layer was changed to 483g / m 2 .

[0080] Alpha Cabin sound absorption tests were conducted on Examples 1, 2, Comparative Example 1, and Comparative Example 2. The test results are shown in the table below, and the test graphs are shown in the figure below. Figures 2 to 5 As shown.

[0081] Test instrument: Alpha Cabin small mixing chamber; Test conditions: 1.0*1.2m flat plate sample, 18~25℃, humidity>50%; Test method: ISO 354:2003;

[0082] 400Hz 500Hz 630Hz 800Hz 1000Hz Example 1 0.31 0.69 0.79 1.04 1.09 Example 2 0.56 0.95 1.16 1.07 1.02 Comparative Example 1 0.20 0.30 0.40 0.50 0.60 Comparative Example 2 0.30 0.40 0.50 0.60 0.70

[0083] Based on the above analysis, Example 1, compared with Comparative Example 1 and Comparative Example 2, has a concentration of 450 g / m³. 2 The sound absorption efficiency of PET sound-absorbing cotton at 400-1000HZ was improved to 0.31, 0.69, 0.79, 1.04, and 1.09, respectively. In Example 2, the sound absorption efficiency was 600g / m³. 2 The sound absorption efficiency of PET sound-absorbing cotton at 400-1000HZ was increased to 0.56, 0.95, 1.16, 1.07, and 1.02, respectively. Both Examples 1 and 2 met the sound absorption requirements.

[0084] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A low-frequency, high-sound-absorbing cotton for electric vehicles, characterized in that, It includes a non-woven fabric (1), a coating layer (2), and a sound-absorbing layer (3) arranged from top to bottom. The material of the coating layer (2) is PE, and the total thickness of the nonwoven fabric (1) and the coating layer (2) is 0.1-0.3mm; The nonwoven fabric (1) is made of PP; The sound-absorbing layer (3) is made of a mixture of PET low-melting-point fiber, ultrafine PET fiber and acrylic fiber, with a weight ratio of (20-25):(50-60):(20-25). The nonwoven fabric (1) has a basis weight of 50-100 g / m². 2 ; The basis weight of the coating layer (2) is 20-50 g / m³. 2 ; The weight of the sound-absorbing layer (3) is 300-1000 g / m³. 2 .

2. A method for manufacturing low-frequency, high-sound-absorbing cotton for electric vehicles as described in claim 1, characterized in that, Includes the following steps: S1: Making the sound-absorbing layer: Open and mix low-melting-point PET fibers, ultra-fine PET fibers and acrylic fibers evenly, and then comb them to obtain the sound-absorbing layer; S2: Laying and shaping: The sound-absorbing layer after S1 is combed is laid into a mesh, and then PE powder is sprinkled on the PP non-woven fabric with PE coating and the PE coating side is laid with the sound-absorbing layer facing the sound-absorbing layer to obtain the sound-absorbing cotton to be composited. S3: Composite molding: The sound-absorbing cotton to be composited in S2 is transported to the drying room for heating and molding.

3. In the method for manufacturing low-frequency, high-sound-absorbing cotton for electric vehicles according to claim 2, in step S2, the amount of PE powder sprinkled is 12-20 g / m². 2 .

4. In the method for manufacturing low-frequency high-sound-absorbing cotton for electric vehicles according to claim 2, in step S3, the temperature of the drying chamber is set to 200-300℃.

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