Preparation method of sound-absorbing and sound-insulating composite material laminated plate

Abstract

The invention relates to the technical field of composite material structure design, in particular to a sound-absorbing and sound-insulating composite material laminated plate and a preparation method thereof.The laminated plate comprises a base body, reinforcement bodies and a sandwich material, the reinforcement bodies and the sandwich material are wrapped with the base body, and the reinforcement bodies and the sandwich material are sequentially and alternately arranged; the matrix is prepared by mixing epoxy resin, a curing agent and a diluent; the reinforcement body is carbon fiber or glass fiber, and the weaving direction of the carbon fiber or glass fiber is unidirectional, plain or twill; and the sandwich material is plant fiber with a hollow structure. When the laminated plate is manufactured, vacuum pressure is adjusted by controlling a vacuum valve through a vacuum bag press forming process, so that the sound insulation effect is adjusted. The laminated plate has high surface area and porosity, the sound absorption effect of the laminated plate is improved, and the laminated plate has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material structure design, and particularly to a sound-absorbing and sound-insulating composite laminate and a preparation method thereof. Background Art

[0002] Sound insulation boards are important materials for reducing noise and play an important role in various occasions where noise needs to be reduced. Traditional sound insulation materials are mostly heavy, which limits their application scope. A lot of work has been done at home and abroad in the research of lightweight sound insulation materials. For example, Xin Fengxian et al. theoretically studied the sound insulation performance of lightweight metal sandwich panels, showing that the sandwich-structured plates have good sound insulation performance. Yu Laiming et al. studied the influence of the arrangement form of reinforcing materials on the sound insulation performance of composite materials. Yang Tianbing et al. studied the sound insulation performance of honeycomb fabric-reinforced polyvinyl chloride composites.

[0003] The research published by Tu Zheng et al., "Sound insulation performance of laminates based on glass fiber-reinforced sound insulation composites", used common pine pressed plates as the base material and glass fiber-reinforced polyvinyl chloride sound insulation materials as the core layer to design and prepare several laminated sound insulation composites with laminated structures. The sound insulation performance of the prepared samples was tested and analyzed using a two-channel acoustic analyzer. The results showed that the sound insulation amount of the prepared 2-cm-thick laminated sound insulation board was greater than 30 dB. However, the laminate of pine pressed plates and glass fiber-reinforced polyvinyl chloride sound insulation materials can meet the sound insulation performance requirements of general occasions to a certain extent, but the combination of pine pressed plates and glass fiber-reinforced polyvinyl chloride sound insulation materials has relatively weak sound absorption ability.

[0004] In addition, due to factors such as the matrix material, fiber content, and lay-up method used in current glass fiber laminates, there are extremely large differences in their strength data. Therefore, on the basis of considering the sound absorption and sound insulation performance of the laminate, it is also necessary to fully consider the bending strength and impact strength of the product. Summary of the Invention

[0005] In view of the problems existing in the sound-absorbing and sound-insulating composite laminate provided by the prior art, the present invention proposes a sound-absorbing and sound-insulating composite laminate and a preparation method thereof.

[0006] A sound-absorbing and sound-insulating composite laminate includes a matrix, a reinforcement, and a core material. The matrix wraps around the reinforcement and the core material, and the reinforcement and the core material are alternately arranged in sequence, where: The matrix is made by mixing epoxy resin, a curing agent, and a diluent; The reinforcement is carbon fiber or glass fiber, and the weaving direction of the carbon fiber or glass fiber is unidirectional, plain, or twill; Among them, the plant fiber of the sandwich material is selected from sisal scraps generated during machining, weaving, and production processes, and the optimal range of the single root length is 0 - 3 cm. This way of utilizing waste sisal scraps not only realizes the recycling of resources, reduces production costs, but also provides unique acoustic and mechanical properties for the sound-absorbing and sound-insulating composite laminate.

[0007] Preferably, the mass ratio of epoxy resin, curing agent, and diluent in the matrix is 100:10 - 30:10 - 20.

[0008] Preferably, the mass ratio of the reinforcement: sandwich material: matrix is 1:1:1 - 2.

[0009] A preparation method of a sound-absorbing and sound-insulating composite laminate is prepared by a vacuum bag molding process and is implemented according to the following steps: 1) Mold preparation: Place a hard silicone plate in the mold to ensure the flatness of the laminate. 2) Material laying: Lay the matrix, reinforcement, and sandwich material and place them in the mold. Among them, the laying angles of the reinforcements in adjacent layers adopt any one of 0° / 0°, 0° / ±90°, 0° / ±45°, or ±45° / ±90°, and the sisal fibers are randomly and evenly laid as the sandwich layer. 3) Vacuum bag installation: Put the vacuum bag outside the mold and seal it. 4) Vacuum pumping: Use a pressure reducing valve to control the vacuum pressure, pump the vacuum, and make the vacuum pressure reach 0.55 - 0.75 atmospheres. 5) Curing: Under the vacuum pressure, put the mold into a curing furnace and heat it according to a predetermined temperature curve. The curing temperature is 100°C - 120°C, and the curing time is 90 - 120 minutes. 6) Post-treatment: After curing, cool the mold and the laminate to room temperature, remove the vacuum bag and the mold, and check that the laminate meets the design requirements.

[0010] The positive progress effects obtained by the present invention: 1) Using a mixture composed of epoxy resin, curing agent, diluent, etc. in a certain proportion as the matrix, and carbon fiber or glass fiber as the reinforcement, and adding plant fibers with a hollow structure as the sandwich material can make the laminate have good interfacial properties and bonding strength, increase the strength of the laminate, and is beneficial to improving the performance of the composite material. 2) By controlling the vacuum pressure of the pumped mixture to control the porosity of the sandwich material in the laminate, it helps to improve the sound-absorbing and sound-insulating effect of the laminate. 3) Plant fiber, as a natural material, is widely found in plant stems and roots. Plant fiber is composed of many slender fiber bundles, which have a hollow structure inside and a high surface area and porosity, which helps to improve the sound absorption effect of laminates and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of the application. The examples and their descriptions are used to explain the present application and do not constitute improper limitations on the present application. Figure 1 Schematic diagram of the laminate lay-up format. DETAILED DESCRIPTION

[0012] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0013] Example 1: A sound-absorbing and sound-insulating composite laminate, comprising a matrix, a reinforcement and a core material, wherein the matrix is ​​wrapped around the reinforcement and the core material. The matrix is ​​made of epoxy resin, curing agent and diluent mixed in a mass ratio of 100:10:10; the reinforcement is carbon fiber, the weaving direction of the carbon fiber or glass fiber is unidirectional, and it is cut into 20×20 cm squares, a total of three portions; the core material is sisal fiber, and the sisal fiber is the scraps generated during sisal machining, weaving and production, and has a hollow structure. The length of a single plant fiber ranges from 0 to 3 cm. The sisal fiber is weighed according to a mass ratio of carbon fiber to sisal fiber of 1:1, and the sisal fiber is divided into two portions. The mass ratio of the reinforcement: core material: matrix is ​​1:1:2. In the mold, carbon fiber cloth, sisal fiber, carbon fiber cloth and sisal fiber are laid in order from bottom to top; the carbon fiber cloth is laid at 0° / 0°, and the sisal fiber is laid randomly and evenly, see Figure 1 .

[0014] Place a hard silicone sheet on top of the mold and seal it with a vacuum bag to ensure the laminate is flat; The preparation method of the matrix is ​​as follows: epoxy resin, curing agent and diluent are mixed in proportion, stirred evenly, placed in a vacuum oven to draw vacuum and heated at 40°C for 20 minutes to reduce the air content in the mixture; The pressure was adjusted to 0.55 vacuum pressure using a vacuum valve, and the mixture was pumped into the mold using a vacuum pump until the reinforcement and the core material were completely immersed, and then cured in a drying environment at 120°C for 90 minutes.

[0015] The sound-absorbing and sound-insulating composite laminate prepared by the above process has a bending strength of about 100 MPa and an impact strength of about 60 kJ / m² for the product. This may be because the randomly oriented short sisal fibers enhance the damping coefficient of the composite material and interlock with the fabric, forming a firm fiber-matrix interface bond and improving the mechanical properties.

[0016] Example 2: Adjust the vacuum valve pressure to 0.65 vacuum pressure and implement according to the above steps to obtain Example 2.

[0017] Example 3: Adjust the vacuum valve pressure to 0.75 vacuum pressure and implement according to the above steps to obtain Example 3.

[0018] Comparative Example 1: Adjust the vacuum valve pressure to 1.0 vacuum pressure and implement according to the above steps to obtain Comparative Example 1.

[0019] Comparative Example 2: Adjust the vacuum valve pressure to 0.45 vacuum pressure and implement according to the above steps to obtain Comparative Example 1.

[0020] The laminate prepared by the present invention was tested with lightweight materials, and the specific test results are as follows in the table: Test method: For the composite laminates prepared in Examples 1-3, their performance was tested. Before the test, the samples were pre-placed under standard experimental conditions of a temperature of 23 ± 2 °C and a relative humidity of 50 ± 5% for at least 24 hours; the performance characterization of the composite laminates was tested according to the specified standards.

[0021] Sound-absorbing and sound-insulating test: Tested according to the GB / T 18696.2-2002 standard, and the results are as follows: As can be seen from Table 1, the composite laminate prepared by the present invention has good sound-absorbing and sound-insulating effects and has good application prospects.

[0022] Comparative Example 3: Recorded in the paper "Preparation and Properties of Carbon Fiber Hybrid Sisal Fiber Reinforced Polypropylene Composites" published by Yang Jinghao et al., its bending strength is 51 MPa, the impact strength is 60 kJ / m² for the impact strength, and the bending strength is 51 MPa.

[0023] Comparative Example 4: As recorded in the paper "Investigation of mechanical and thermal behavior of sisal fiber reinforced polymer biocomposites" published by S.S. Rana et al., the impact strength of the sisal fiber reinforced epoxy resin biocomposite with a length of 5 mm is 6.20 KJ / M2, and the flexural strength is 49.35 MPa. The reason is that no carbon fiber is added to this product, resulting in poor strength.

[0024] Comparative Example 5: As recorded in the paper "Decay resistance, thermal degradation, tensile and flexural properties of sisal carbon hybrid composites" published by Tufan et al., the impact strength of the combination of sisal fiber and carbon fiber used by them is only 45.33 MPa. The estimated length of the short sisal fiber used is 10 - 60, mainly concentrated between 15 - 35.

[0025] It can be seen from Comparative Examples 3 - 5 that the strength performance of the composite laminate prepared by the present invention is good.

Claims

1. A sound-absorbing and sound-insulating composite laminate, characterized in that It includes a matrix, a reinforcement and a core material, the matrix is ​​wrapped outside the reinforcement and the core material, and the reinforcement and the core material are arranged alternately in sequence, wherein: The matrix is ​​made by mixing epoxy resin, curing agent and diluent; The reinforcement is carbon fiber or glass fiber, and the weaving direction of the carbon fiber or glass fiber is unidirectional, plain or twill; The sandwich material is sisal fiber, and the length of a single sisal fiber is in the range of 0-3 cm.

2. A sound-absorbing and sound-insulating composite laminate according to claim 1, characterized in that The mass ratio of epoxy resin, curing agent and diluent in the matrix is ​​100:10~30:10~20.

3. A sound-absorbing and sound-insulating composite laminate according to claim 1, characterized in that The mass ratio of reinforcement: core material: matrix is ​​1:1:1~2.

4. A method for preparing a sound-absorbing and sound-insulating composite laminate, which is prepared by a vacuum bagging process and is implemented in the following steps: Mold preparation: Place a hard silicone sheet in the mold to ensure the flatness of the laminate; Material laying: Lay out the matrix, reinforcement and core materials and put them into the mold. The laying angle of the reinforcements of two adjacent layers is any one of 0° / 0°, 0° / ±90°, 0° / ±45°, or ±45° / ±90°, and the sisal fiber as the core layer is randomly and evenly laid; Vacuum bag installation: put the vacuum bag on the outside of the mold and seal it; Vacuuming: Use a pressure reducing valve to control the vacuum pressure and draw the vacuum to make the vacuum pressure reach 0.55~0.75 atmospheres; Curing: Under vacuum pressure, place the mold in a curing furnace and heat it according to a predetermined temperature curve. The curing temperature is 100°C~120°C and the curing time is 90~120 minutes. 6) Post-processing: After curing is completed, cool the mold and laminate to room temperature, remove the vacuum bag and mold, and check that the laminate meets the design requirements.

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