Electrode system for preparing composite material

Abstract

The utility model relates to the technical field of composite material preparation equipment, in particular to an electrode system for preparing a composite material, which comprises a mold, an electrode plate arranged in the mold, and a semi-conductive layer covered on the surface of the electrode plate, the semi-conductive layer is specifically attached to the side, close to the composite material, of the electrode plate, the effect of eliminating the defects of unsmoothness and tiny protrusions on the surface of the electrode is achieved, the space electric field gradient of the surface of the electrode can be reduced, space charges are prevented from moving from the electrode plate to the composite material, injection of charges in the composite material and formation of electric branches are inhibited, and the service life of the electrode plate is prolonged. According to the invention, a semi-conductive layer and an electrode plate are combined to form an electrode system capable of improving the breakdown field intensity, and in the early stage of composite material curing, it is ensured that the whole system is not broken down, and at the same time, higher voltage can be applied to two ends of a sample to promote oriented arrangement of filler in a composite material matrix.

Description

Technical Field

[0001] This utility model relates to the field of composite material preparation equipment technology, and in particular to an electrode system for composite material preparation. Background Technology

[0002] Polymers possess a comprehensive set of excellent properties, including excellent chemical inertness, plasticity, low shrinkage, and electrical insulation, making them widely used in power system insulation. However, most polymers inherently have poor thermal conductivity, failing to meet the ever-increasing heat dissipation demands and hindering equipment development. Currently, a widely accepted method to improve the thermal conductivity of polymers is to fill them with highly thermally conductive fillers. When the filler content is low, the fillers exist in an island-like manner, resulting in a still low thermal conductivity composite material. Therefore, to obtain polymer-based composites with high thermal conductivity, filler content as high as 60%-70% is often required. However, when the filler content is high, the mechanical properties of the composite material decrease significantly. Thus, the preparation of high thermal conductivity composite materials with low filler content has become a research hotspot in the field of composite material preparation. Studies have found that applying an electric field during the composite material preparation process polarizes the fillers in the matrix material, causing local orientation and global alignment of the fillers to construct efficient thermal conduction channels. Therefore, the external electric field-induced method has become a new method for preparing insulating composite materials with high thermal conductivity at low filler content.

[0003] However, during the preparation process, the copper electrode is exposed to a high-temperature environment, which makes it prone to oxidation. Copper oxide is generated locally or entirely on the electrode surface, resulting in inconsistency between the conductor conductivity and relative permittivity of the electrode surface. This leads to electric field distortion and an increase in the spatial electric field gradient on the electrode surface, which is not conducive to the preparation of oriented composite materials with the same degree of orientation. Furthermore, in the early stage of composite material curing, many matrix-curing agent systems contain a large number of low molecular weight compounds with polar or strongly polar functional groups at the beginning of curing. Their electrical properties, such as insulation resistance, dielectric constant, and dielectric loss, are very poor. Therefore, applying a high-intensity electric field in the early stage of curing can lead to the breakdown of the entire system, affecting the preparation of composite materials. Utility Model Content

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0005] In view of the technical problem in the above-mentioned prior art that a high electric field strength can cause the entire system to break down during the preparation of composite materials, this utility model is proposed.

[0006] The purpose of this invention is to provide an electrode system for the preparation of composite materials.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an electrode system for the preparation of composite materials, comprising a mold, an electrode plate disposed inside the mold, and a semi-conductive layer covering the surface of the electrode plate.

[0008] As a preferred embodiment of the electrode system of this invention for the preparation of composite materials, the conductivity and relative permittivity of the semiconducting layer are between those of the electrode plate and the composite material to be prepared.

[0009] As a preferred embodiment of the electrode system for preparing composite materials according to this utility model, the semiconductive layer is covered on the surface of the electrode plate by thermosetting.

[0010] As a preferred embodiment of the electrode system of this invention for the preparation of composite materials, the thickness of the semiconductive layer is 0.1 mm.

[0011] As a preferred embodiment of the electrode system for preparing composite materials according to this invention, the semiconductive layer is composed of a matrix and micro / nano conductive fillers.

[0012] As a preferred embodiment of the electrode system of this invention for the preparation of composite materials, the matrix is ​​an ethylene-vinyl acetate copolymer.

[0013] In a preferred embodiment of the electrode system for preparing composite materials according to this invention, the conductive filler is carbon black.

[0014] As a preferred embodiment of the electrode system for the preparation of composite materials according to this utility model, there are two electrode plates, and the two electrode plates are arranged opposite each other on both sides inside the mold.

[0015] In a preferred embodiment of the electrode system for preparing composite materials according to this utility model, the electrode plate is a copper plate.

[0016] As a preferred embodiment of the electrode system for preparing composite materials according to this utility model, the mold is an integrally molded structure of polytetrafluoroethylene.

[0017] The beneficial effects of the electrode system for composite material preparation of this utility model are as follows: The semiconductive layer is specifically attached to the side of the electrode plate close to the composite material, which not only eliminates the roughness and minor protrusion defects on the electrode surface, but also reduces the spatial electric field gradient on the electrode surface, inhibits the movement of space charge from the electrode plate to the composite material, inhibits the injection of charge and the formation of electrical trees in the composite material, and reduces the spatial electric field gradient on the electrode surface. The combination of the semiconductive layer and the electrode plate forms an electrode system that can improve the breakdown field strength. In the early stage of composite material curing, while ensuring that the entire system is not broken down, a higher voltage can be applied to both ends of the sample to promote the orientation and alignment of fillers in the composite material matrix. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] Figure 2 This is a global electric field distribution diagram used to simulate the electrode system for preparing oriented composite materials in existing technologies using the finite element method.

[0021] Figure 3 This is a global electric field distribution diagram used to simulate the electrode system for composite material preparation in this invention using the finite element method.

[0022] Figure 4 This is an electric field diagram on the surface of the electrode plate used to simulate the electrode system for preparing oriented composite materials in existing technologies using the finite element method.

[0023] Figure 5 The electric field diagram on the surface of the electrode plate is used to simulate the electrode system for the preparation of composite materials in this invention using the finite element method. Detailed Implementation

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0027] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides an electrode system for the preparation of composite materials, comprising:

[0028] Mold 100;

[0029] Electrode plate 200, which is disposed inside mold 100;

[0030] A semiconductive layer 300 is applied to the surface of the electrode plate 200.

[0031] The semiconductive layer 300 is specifically attached to the side of the electrode plate 200 near the composite material 400. It not only eliminates the roughness and minor protrusions on the electrode surface, but also reduces the spatial electric field gradient on the electrode surface, inhibits the movement of space charge from the electrode plate 200 to the composite material 400, and inhibits the injection of charge and the formation of electrical trees in the composite material 400. The combination of the semiconductive layer 300 and the electrode plate 200 forms an electrode system that can improve the breakdown field strength. In the early stage of curing of the composite material 400, while ensuring that the entire system is not broken down, a higher voltage can be applied to both ends of the sample to promote the orientation and alignment of the filler in the matrix of the composite material 400.

[0032] Example 2, refer to Figure 1 This is the second embodiment of the present invention. Unlike the previous embodiment, the conductivity and relative permittivity of the semiconductive layer 300 are between those of the electrode plate 200 and the composite material 400 to be prepared.

[0033] Furthermore, the semiconductive layer 300 is thermally cured and covered on the surface of the electrode plate 200; the thickness of the semiconductive layer 300 is 0.1 mm; the semiconductive layer 300 is composed of a matrix and micro / nano conductive fillers; the matrix is ​​ethylene-vinyl acetate copolymer; the conductive filler is carbon black.

[0034] The specific attachment process of the semiconductive layer 300 is as follows: ethylene-vinyl acetate copolymer and carbon black are mixed, and then the mixed material together with the electrode plate 200 is placed in a curing device for curing, so that a 0.1 mm semiconductive layer 300 is attached to the surface of the electrode plate 200. Specifically, the mixed material of ethylene-vinyl acetate copolymer and carbon black is placed on one side of the electrode plate 200, so that a semiconductive layer 300 is attached to one side of the electrode plate 200. In use, the side of the electrode plate 200 with the semiconductive layer 300 attached is in contact with the composite material 400 to be prepared.

[0035] Example 3, referring to Figure 1 This is the third embodiment of the present invention. Unlike the previous embodiment, there are two electrode plates 200, and the two electrode plates 200 are arranged opposite each other on both sides inside the mold 100.

[0036] Furthermore, electrode plate 200 is a copper plate.

[0037] Furthermore, mold 100 is a one-piece molded structure of polytetrafluoroethylene.

[0038] Mold 100 is made of polytetrafluoroethylene, which is heat resistant and does not easily stick to epoxy resin.

[0039] like Figure 2-5 As shown, simulation of the entire system using the finite element method reveals that without the semiconductive layer 300, the electric field strength increases from 0 to a peak value from the sample surface to a depth of 0.004 mm within the sample, with a spatial electric field gradient of 2050 kV / mm². However, with the addition of the semiconductive layer 300, the electric field strength increases from 0 to a peak value from the sample surface to a depth of 0.065 mm within the sample, with a spatial electric field gradient of 126.2 kV / mm². Therefore, it can be concluded that adding a semiconductive layer 300 to the surface of the electrode plate 200... Subsequently, the increase in field strength slows down, and the spatial electric field gradient is reduced to 6% of its original value. As a result, the electric field force on the electrons excited from the electrode plate 200 is greatly reduced, and their energy is lower, thus reducing the probability of electron avalanche formation. In summary, the addition of the semiconductive layer 300 can not only effectively suppress the movement of charge from the copper plate to the sample from the source, but also slow down the change of the electric field on the sample surface, greatly reducing the energy of the charge and avoiding the formation of electron avalanche. This ensures that the overall system is not broken down when a high electric field is applied to prepare the orientation composite material 400.

[0040] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of this utility model. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structural equivalents but also equivalent structures. Without departing from the scope of this invention, other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments. Therefore, this invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0041] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the present invention as currently considered, or those features that are not relevant to implementing the present invention) may be omitted.

[0042] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An electrode system for preparing composite materials, characterized in that: include, Mold (100); Electrode plate (200), the electrode plate (200) is disposed inside the mold (100); A semiconductive layer (300) is provided, which covers the surface of the electrode plate (200).

2. The electrode system for preparing composite materials as described in claim 1, characterized in that: The conductivity and relative permittivity of the semiconductive layer (300) are between those of the electrode plate (200) and the composite material (400) to be prepared.

3. The electrode system for preparing composite materials as described in claim 2, characterized in that: The semiconductive layer (300) is thermally cured and covered on the surface of the electrode plate (200).

4. The electrode system for composite material preparation as described in claim 3, characterized in that: The thickness of the semiconductive layer (300) is 0.1 mm.

5. The electrode system for composite material preparation as described in claim 4, characterized in that: There are two electrode plates (200), and the two electrode plates (200) are arranged opposite each other on both sides inside the mold (100).

6. The electrode system for composite material preparation as described in claim 5, characterized in that: The electrode plate (200) is a copper plate.

7. The electrode system for preparing composite materials as described in claim 6, characterized in that: The mold (100) is a one-piece molded structure of polytetrafluoroethylene.

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