Composite material structure

Abstract

A composite material structure according to the present invention comprises a sound-absorbing material and a fiber-reinforced resin.　Additionally, the sound-absorbing material is wrapped in oil-repellent wrapping paper, and the fiber-reinforced resin adheres closely to the wrapping paper and covers the entirety of the sound-absorbing material wrapped in the wrapping paper, whereby adhesion between the fiber-reinforced resin and the sound-absorbing material can be prevented and a composite material structure enabling 100% reuse of the sound-absorbing material can be provided.

Description

[Technical Field]

[0001] The present invention relates to a composite material structure, and more particularly to a composite material structure suitable for use as a sound-silencing panel for a vehicle. [Background technology]

[0002] Electric vehicles produce less noise from their motors than vehicles with conventional engines, and the noise inside an electric vehicle is dominated by wind noise and road noise while driving, so there is a greater demand for measures to prevent noise generated from sources other than the motor.

[0003] Patent Document 1 discloses a composite material structure that can be used for automobile panel materials, etc., in which high-density permeation-suppressing layers are provided on both sides of a nonwoven fabric to prevent the matrix resin of a fiber-reinforced resin from penetrating into the nonwoven fabric. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-214141 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the product described in Patent Document 1, a portion of the nonwoven fabric is heated and compressed to form a permeation suppression layer, which reduces the sound absorption properties of this portion. In addition, since the permeation suppression layer is adhered to the matrix resin of the fiber-reinforced resin, it is difficult to separate the nonwoven fabric from the fiber-reinforced resin when recycling the composite material structure, and the recyclability of the nonwoven fabric is low.

[0006] The present invention was made in consideration of the problems associated with the prior art, and its purpose is to provide a composite material structure that has excellent sound absorption properties and allows 100% reuse of the sound-absorbing material. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above-mentioned objective, the inventor discovered that the above-mentioned objective could be achieved by wrapping the sound-absorbing material in oil-repellent wrapping paper to prevent adhesion between the matrix resin of the fiber-reinforced resin and the sound-absorbing material, and thus completed the present invention.

[0008] That is, the composite material structure of the present invention comprises a sound-absorbing material and a fiber-reinforced resin. The sound-absorbing material is wrapped in oil-repellent wrapping paper, and the fiber-reinforced resin is in close contact with the entire surface of the wrapping paper that is wrapped around the sound-absorbing material, covering the sound-absorbing material. [Effects of the Invention]

[0009] According to the present invention, the sound-absorbing material is wrapped in oil-repellent wrapping paper to prevent adhesion between the matrix resin of the fiber-reinforced resin and the sound-absorbing material, thereby providing a composite material structure in which the sound-absorbing material is 100% recyclable. [Brief explanation of the drawings]

[0010] [Figure 1] 1A to 1C are diagrams illustrating the state of forming a composite material structure. [Figure 2] FIG. 1 is a cross-sectional view showing an example of a composite material structure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The composite material structure of the present invention will now be described in detail. The composite material structure of the present invention comprises a sound-absorbing material and a fiber-reinforced resin. The fiber-reinforced resin maintains the shape of the composite material structure. The sound-absorbing material is entirely covered with the fiber-reinforced resin, and vibrates finely in response to sound (vibration energy) incident on the composite material structure, converting the vibrational energy of the sound into thermal energy to absorb the sound.

[0012] The composite material structure can be produced simultaneously with the production of the fiber reinforced resin, rather than by combining the fiber reinforced resin and the sound absorbing material, which are each produced separately.

[0013] Generally, the fiber-reinforced resin is produced by impregnating a fiber sheet such as a woven or nonwoven fabric with a matrix resin in a mold and then curing or solidifying the matrix resin. As shown in Figure 1, the sound-absorbing material is covered on both sides with the fiber sheets, which are then impregnated with the matrix resin, allowing a composite material structure to be produced simultaneously with the production of the fiber-reinforced resin.

[0014] However, if the sound-absorbing material is simply covered with the fiber sheet, the matrix resin impregnated in the fiber sheet will penetrate the fiber sheet and reach the sound-absorbing material, bonding the sound-absorbing material and the fiber-reinforced resin together, making separation difficult and reducing the recyclability of the sound-absorbing material.In addition, the matrix resin will penetrate into the sound-absorbing material and solidify, inhibiting vibration of the sound-absorbing material and reducing sound-absorbing performance.

[0015] In the composite material structure of the present invention, as shown in Figure 2, the sound-absorbing material is wrapped in oil-repellent wrapping paper. This prevents the wrapping paper from repelling the matrix resin and bonding between the fiber-reinforced resin and the sound-absorbing material, thereby preventing a decrease in the recyclability of the sound-absorbing material and a decrease in its sound-absorbing performance. This allows for a reduction in the amount of sound-absorbing material and matrix resin used, making the product lighter and less expensive. Note that "wrapped in wrapping paper" means that the sound-absorbing material does not come into contact with the matrix resin. It is acceptable for there to be small gaps, such as where the wrapping paper overlaps, and for a small amount of matrix resin to enter these gaps between the wrapping paper.

[0016] Furthermore, because the sound-absorbing material is impregnated with the matrix resin while covered with a fiber sheet, the fiber-reinforced resin adheres to the entire surface of the wrapping paper encasing the sound-absorbing material, preventing the sound-absorbing material from shifting inside the composite material structure. Therefore, there is no space between the sound-absorbing material and the wrapping paper, or between the wrapping paper and the fiber-reinforced resin, and sound that enters the composite material structure is absorbed by the sound-absorbing material and does not pass through, resulting in excellent sound absorption performance.

[0017] The wrapping paper can be one that has oil repellency to repel and prevent penetration of the matrix resin during molding of the composite material structure, and has heat resistance to the extent that it does not change even when it comes into contact with the matrix resin during molding of the composite material structure.

[0018] The heat resistance of the wrapping paper is preferably 150°C or higher, more preferably 200 to 300°C.

[0019] The wrapping paper may be, for example, a paper base coated with an oil-repellent material. Because the base material of the wrapping paper is paper, even if the matrix resin gets into wrinkles or gaps in the wrapping paper and causes the wrapping paper and fiber-reinforced resin to stick together, the sound-absorbing material can be easily removed by tearing the wrapping paper, and the torn wrapping paper can be incinerated.

[0020] Examples of the oil repellent material include fluororesin, silicone resin, polypropylene, polyethylene, polyacetal, etc. Among these, fluororesin and silicone resin are preferred because of their excellent oil repellency and heat resistance.

[0021] As the sound absorbing material, porous sound absorbing materials such as a fiber aggregate having pores between the fibers or a sponge, as well as diaphragm sound absorbing materials and resonance type sound absorbing materials can be used. Among these, a sound absorbing material made of a fiber assembly is preferably used because it has excellent sound absorbing properties and is lightweight.

[0022] Examples of the fibers forming the fiber sheet of the fiber-reinforced resin include carbon fibers and glass fibers.

[0023] As the matrix resin of the fiber-reinforced resin, thermosetting resins such as epoxy resins and phenolic resins, as well as thermoplastic resins such as polyethylene, polypropylene, and polystyrene, can be used. Among these, epoxy resins are preferably used because the monomer has low viscosity, which allows it to easily penetrate between fibers in fiber sheets such as woven fabrics and nonwoven fabrics, and they also have high heat resistance.

[0024] The composite material structure of the present invention can be molded not only into a plate shape but also into a hat shape or other shape depending on the area of ​​use, and since it absorbs incident sound, it can be used in vehicle undercovers and door trims, etc., to absorb sound that enters the vehicle interior and reduce noise. [Explanation of symbols]

[0025] 1 Composite resin material structure 2. Sound-absorbing material 3 wrapping paper 4 Fiber-reinforced resin 5 Fiber sheet 6. Matrix Resin 7. Mold

Claims

1. A composite material structure comprising a sound-absorbing material and a fiber-reinforced resin, The sound-absorbing material is wrapped in oil-repellent wrapping paper, A composite material structure characterized in that the fiber reinforced resin covers the sound absorbing material by adhering to the entire surface of the wrapping paper that encases the sound absorbing material.

2. 2. The composite material structure according to claim 1, wherein the core material is a fiber aggregate.

3. 2. The composite material structure according to claim 1, wherein the matrix resin of the fiber reinforced resin is an epoxy resin.

4. 2. The composite material structure according to claim 1, wherein the wrapping paper contains a fluororesin.

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