A structure wave-absorbing heat-dissipating flexible composite material and a preparation method thereof

Abstract

This invention discloses a flexible composite material for absorbing electromagnetic waves and its preparation method. The method includes the following steps: (1) providing a short fiber fabric, which includes a fabric body and fibers connected to the fabric body; (2) processing the short fiber fabric so that the surface of the fibers in the short fiber fabric is coated with a first metal layer, which is a nickel layer, a nickel-copper layer, or a copper layer; (3) coating the surface of the first metal layer with a second metal layer, which is a black nickel layer or a gunmetal nickel layer, and the fibers and the first metal layer and the second metal layer sequentially coated on the surface of the fibers form metal hairs to obtain a semi-finished product; (4) providing a substrate layer, on which a graphite film is stacked; (5) compositing one side of the semi-finished product with the graphite film, and embedding the metal hairs on the side close to the graphite film into the graphite film to obtain a flexible composite material for absorbing electromagnetic waves. This flexible composite material for absorbing electromagnetic waves can both dissipate heat quickly and absorb electromagnetic waves, and its preparation process is simple and low in cost.

Description

Technical Field

[0001] This invention relates to the technical field of heat dissipation and microwave absorption material preparation, and in particular to a flexible composite material for structural microwave absorption and heat dissipation and its preparation method. Background Technology

[0002] With the increasing integration of electronic devices, electromagnetic interference between devices has become a major factor affecting the normal operation of equipment and operators. Simultaneously, high integration also leads to higher power consumption and concentrated heat. If internal heat is not dissipated in time, the equipment will malfunction, affecting efficiency. Currently, electromagnetically sensitive electronic components are typically covered with absorbing sheets to reduce electromagnetic interference (noise) and ensure normal operation. The sources of electromagnetic interference include electromagnetic waves from other electronic components or reflected electromagnetic waves from the sensitive components. Generally, the thicker the absorbing sheet, the better its absorption effect, reducing electromagnetic interference. However, thicker absorbing sheets hinder heat dissipation, potentially exacerbating the risk of overheating.

[0003] Therefore, it is necessary to develop a flexible composite material for structural wave absorption and heat dissipation to address the aforementioned technical deficiencies. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a flexible composite material with structural wave absorption and heat dissipation, comprising the following steps:

[0005] (1) Provide a short fiber fabric, the short fiber fabric comprising a fabric body and fibers connected to the fabric body;

[0006] (2) The short fiber fabric is processed such that the surface of the fibers in the short fiber fabric is covered with a first metal layer, wherein the first metal layer is a nickel layer, a nickel-copper layer or a copper layer.

[0007] (3) A second metal layer is coated on the surface of the first metal layer, the second metal layer being a black nickel layer or a gunmetal nickel layer, and the fiber and the first metal layer and the second metal layer sequentially coated on the surface of the fiber form metal hairs to obtain a semi-finished product;

[0008] (4) A substrate layer is provided, wherein a graphite film is stacked on the surface of the substrate layer;

[0009] (5) The semi-finished product is laminated with one side facing the graphite film, and the metal hair on the side close to the graphite film is embedded in the graphite film to obtain a flexible composite material with wave absorption and heat dissipation structure.

[0010] Compared with existing technologies, the preparation method of the structural wave-absorbing and heat-dissipating flexible composite material of the present invention cleverly utilizes the short-fiber structure on the fabric. First, a first metal layer is formed on its surface, then a second metal layer is formed on the surface of the first metal layer, and finally, it is composited with a graphite film to obtain the structural wave-absorbing and heat-dissipating flexible composite material. That is, several metal fibers resembling loose fibers are formed circumferentially on the fabric body. Both the first and second metal layers have good heat dissipation effects, thus giving the metal fibers excellent heat dissipation capabilities. The heat from the heat source is rapidly dispersed through the graphite film and then rapidly radiated away through the metal fibers, effectively improving the heat dissipation effect. Simultaneously, the metal fibers on the side away from the graphite film, due to the gaps between them, form a black hole effect, which can absorb electromagnetic waves. Therefore, the structural wave-absorbing and heat-dissipating flexible composite material of the present invention can both dissipate heat quickly and absorb electromagnetic waves, and the preparation process is simple and low-cost.

[0011] In some embodiments, in step (1), the length of the fibers in the short fiber fabric is controlled to be 1-20 μm.

[0012] In some embodiments, in step (1), the fibers on the side of the short fiber fabric closest to the graphite film are short fibers, and the length of the short fibers is controlled to be 1-5 μm;

[0013] The fibers on the side of the short fiber fabric furthest from the graphite film are long fibers, and the length of the long fibers is controlled to be 5-20 μm.

[0014] In some embodiments, the length of the short hair is controlled to be 1-4 μm; the length of the long hair is controlled to be 8-20 μm.

[0015] In some embodiments, in step (1), the short fiber fabric is selected from at least one of polyester fabric, fiberglass fabric, nylon fabric, aramid fabric, and ceramic fiber fabric.

[0016] In some embodiments, in step (2), the first metal layer is formed by chemical plating, electroplating or vacuum plating.

[0017] In some embodiments, after the second metal layer is formed, it is immersed in a color paste to coat the surface of the second metal layer with a coating. The fiber and the first metal layer, the second metal layer and the coating that are sequentially coated on the surface of the fiber form the metal hair.

[0018] Accordingly, the present invention also provides a flexible composite material for absorbing electromagnetic waves and dissipating heat, which is prepared by the above-mentioned method for preparing the flexible composite material for absorbing electromagnetic waves and dissipating heat. This flexible composite material can both dissipate heat quickly and absorb electromagnetic waves. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the structure of the flexible composite material for absorbing and dissipating heat according to the present invention.

[0020] Figure 2 for Figure 1 The enlarged view of point A in the wave-absorbing and heat-dissipating flexible composite material shown.

[0021] Figure 3 This is a process flow diagram for preparing the flexible composite material for absorbing microwave radiation of the present invention.

[0022] Symbol Explanation

[0023] The fabric body 10, fiber 20, long fibers 21, short fibers 23, first metal layer 30, second metal layer 40, coating 50, graphite film 60, substrate layer 70, and metal fibers 100 are included. Detailed Implementation

[0024] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0025] Please refer to Figures 1-2 The flexible composite material for absorbing and dissipating heat according to the present invention includes a woven fabric body 10 and fibers 20 connected to the woven fabric body 10. The surface of the fibers 20 is sequentially covered with a first metal layer 30, a second metal layer 40 and a coating 50. The fibers 20 and the first metal layer 30, the second metal layer 40 and the coating 50 covering the surface of the fibers 20 form metal hairs 100. One side of the woven fabric body 10 is composited with a graphite film 60, and the metal hairs 100 on this side are embedded in the graphite film 60. The other side of the graphite film 60 is provided with a substrate layer 70, which is used to protect the graphite film 60 and can also be used to connect with the outside world.

[0026] Please refer to Figure 3 This invention provides a process flow diagram for the preparation of a flexible composite material with wave-absorbing and heat-dissipating properties. Figure 3 It can be seen that the preparation method includes the following steps:

[0027] (S1) Provide a short fiber fabric, the short fiber fabric including a fabric body 10 and fibers 20 connected to the fabric body 10;

[0028] (S2) The short fiber fabric is processed so that the surface of the fiber 20 of the short fiber fabric is covered with a first metal layer 30, wherein the first metal layer 30 is a nickel layer, a nickel-copper layer or a copper layer.

[0029] (S3) A second metal layer 40 is coated on the surface of the first metal layer 30. The second metal layer 40 is a black nickel layer or a gunmetal nickel layer. The fiber 20 and the first metal layer 30 and the second metal layer 40 coated on the surface of the fiber 20 form a metal wool 100 to obtain a semi-finished product.

[0030] (S4) A substrate layer 70 is provided, wherein a graphite film 60 is stacked on the surface of the substrate layer 70;

[0031] (S5) Composite one side of the semi-finished product with the graphite film 60, and embed the metal hair 100 on the side close to the graphite film 60 into the graphite film to obtain a flexible composite material with structural wave absorption and heat dissipation.

[0032] In the above technical solution, the preparation method of the structural wave-absorbing and heat-dissipating flexible composite material of the present invention cleverly utilizes the short-hair structure on the short-fiber fabric. First, a first metal layer is formed on its surface, then a second metal layer is formed on the surface of the first metal layer, and then it is composited with a graphite film to obtain the structural wave-absorbing and heat-dissipating flexible composite material. That is, several metal hairs resembling pine needles are formed circumferentially on the fabric body. Both the first and second metal layers have good heat dissipation effects, thus giving the metal hairs excellent heat dissipation performance. The heat from the heating element is rapidly dispersed through the graphite film and then rapidly radiated away through the metal hairs, effectively improving the heat dissipation effect. Simultaneously, the metal hairs on the side away from the graphite film, due to the gaps between them, form a black hole effect, which can absorb electromagnetic waves. Therefore, the structural wave-absorbing and heat-dissipating flexible composite material of the present invention can both dissipate heat quickly and absorb electromagnetic waves, and the preparation process is simple and low-cost.

[0033] In some embodiments, the fiber length of the short fiber fabric is controlled to be 1-20 μm, such as 1-5 μm, 5-15 μm, 5-20 μm, or 8-20 μm. For example, the fiber length of the short fiber fabric is controlled to be 1 μm, 3 μm, 5 μm, 7 μm, 10 μm, 15 μm, 17 μm, or 20 μm. Further, the fibers on the side of the short fiber fabric closest to the graphite film (defined as short fibers 23, such as...) are treated by shearing. Figure 3 As shown), this makes the fiber length on this side shorter than the fiber length on the side farther from the graphite film (defined as long fibers 21, such as...). Figure 3 As shown, the fiber length of short hair 23 is controlled to be 1-5μm, preferably 1-4μm, which is more conducive to heat transfer and improves heat dissipation efficiency; the fiber length of long hair 23 is controlled to be 5-20μm, preferably 8-20μm, which is more conducive to absorbing electromagnetic waves.

[0034] In some embodiments, the short fiber fabric is selected from at least one of polyester fabric, fiberglass fabric, nylon fabric, aramid fabric, ceramic fiber fabric, and polyester fiber fabric. As an example, the short fiber fabric is polyester fiber fabric or fiberglass fabric, but is not limited thereto.

[0035] In some embodiments, the first metal layer is formed by chemical plating, electroplating, or vacuum plating. That is, for example, short-fiber fabric is placed in a nickel-containing plating solution, and a first metal layer is formed on the surface of the fibers of the short-fiber fabric by chemical plating, which not only improves the fiber's uprightness but also enhances heat transfer. Furthermore, a black nickel layer or gunmetal nickel layer is formed on the surface of the first metal layer by electroplating or chemical plating, which has excellent corrosion resistance, protects the first metal layer, and also has a matting effect, which is beneficial for promoting electromagnetic wave absorption. For example, a product with a first metal layer already formed is placed in a plating solution that can form black nickel, and a second metal layer is formed on the surface of the first metal layer by electroplating. Surface treatment technologies such as electroplating, chemical plating, and vacuum plating are common technical solutions in this field and will not be described further here.

[0036] It should be understood that graphite films have good heat dissipation properties. To protect the graphite film, a substrate layer is provided. The substrate layer can be made of heat-dissipating materials, such as, but not limited to, cloth substrates, plastic substrates, metal substrates, glass substrates, ceramic substrates, etc. For example, the substrate layer is a cloth substrate, but it is not limited to this.

[0037] In some embodiments, to further improve the microwave absorption performance of the material, the second metal layer is immersed in a color paste after formation to obtain a coating. The color paste is blue, green, yellow, or black. As an example, the second metal layer is immersed in a green color paste to obtain a coating. The components of the green color paste are commonly used color paste materials, and therefore will not be described further.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a flexible composite material with structural wave absorption and heat dissipation, characterized in that, Including the following steps: (1) A short fiber fabric is provided, the short fiber fabric comprising a fabric body and fibers connected to the fabric body; (2) The short fiber fabric is processed such that the surface of the fibers in the short fiber fabric is coated with a first metal layer, wherein the first metal layer is a nickel layer, a nickel-chromium layer, a nickel-copper layer or a copper layer; (3) A second metal layer is coated on the surface of the first metal layer, wherein the second metal layer is a nickel layer, a black nickel layer or a gunmetal nickel layer, and the fiber and the first metal layer and the second metal layer sequentially coated on the surface of the fiber form metal hairs to obtain a semi-finished product; (4) A substrate layer is provided, wherein a graphite film is stacked on the surface of the substrate layer; (5) The semi-finished product is laminated with one side facing the graphite film, and the metal hair on the side close to the graphite film is embedded in the graphite film to obtain a flexible composite material with wave absorption and heat dissipation structure.

2. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 1, characterized in that, In step (1), the length of the fibers in the short fiber fabric is controlled to be 1-20 μm.

3. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 2, characterized in that, In step (1), the fibers on the side of the short fiber fabric closest to the graphite film are short fibers, and the length of the short fibers is controlled to be 1-5 μm; The fibers on the side of the short fiber fabric furthest from the graphite film are long fibers, and the length of the long fibers is controlled to be 5-20 μm.

4. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 3, characterized in that, The length of the short hairs is controlled to be 1-4 μm; the length of the long hairs is controlled to be 8-20 μm.

5. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 1, characterized in that, In step (1), the short fiber fabric is selected from at least one of polyester fabric, glass fiber fabric, nylon fabric, aramid fabric, and ceramic fiber fabric.

6. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 1, characterized in that, In step (2), the first metal layer is formed by chemical plating, electroplating or vacuum plating.

7. The method for preparing the flexible composite material for absorbing and dissipating heat according to claim 1, characterized in that, After the second metal layer is formed, it is immersed in color paste to coat the surface of the second metal layer with a coating. The fiber and the first metal layer, the second metal layer and the coating that are sequentially coated on the surface of the fiber form the metal hair.

8. A flexible composite material for absorbing and dissipating heat, characterized in that, The flexible composite material for absorbing and dissipating heat according to any one of claims 1-7 is prepared.

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