CN107471629A - A kind of continuous fiber reinforced composite materials electromagnetic armouring structure 3D printing manufacture method - Google Patents

Abstract

A kind of continuous fiber reinforced composite materials electromagnetic armouring structure 3D printing manufacture method, first establish shielding construction threedimensional model, then conductive fiber path is designed, 3D conductive fibers path is corrected again, then shielding construction printing path is generated, finally carry out 3D printing and prepare shielding construction, shielding construction produced by the present invention both has higher shield effectiveness, possess relatively low density again, also there is the designability of capability of electromagnetic shielding and mechanical property, can be according to the capability of electromagnetic shielding for needing the shielding construction of application scenario, the continuous fiber composite material used simultaneously has good mechanical performance.

Description

A continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method

technical field

The invention relates to the technical field of 3D printing of continuous fiber reinforced composite materials, in particular to a 3D printing manufacturing method of a continuous fiber reinforced composite material electromagnetic shielding structure.

Background technique

With the rapid development of electronic communication technology in modern society, the number of equipment using electromagnetic wave communication has increased dramatically, and the energy density of electromagnetic waves in the surrounding environment has increased year by year. Electromagnetic radiation will affect human daily life and physical health within a certain range, and will also interfere and infringe The normal operation of other electronic equipment reduces the reliability and stability of the equipment. Electromagnetic waves existing inside electronic communication equipment can also interfere with each other, causing the equipment itself to fail to work properly.

Electromagnetic shielding is one of the most basic and effective technical measures to solve the above problems. Electromagnetic shielding can weaken the field strength caused by certain sources in a certain area of space. Usually, some electromagnetic shielding bodies are installed outside the protected equipment, which will attenuate electromagnetic waves. Traditional electromagnetic shielding bodies are mostly made of metal and its alloy sheets, sheets, thin nets, thin strips and other materials, which are covered on the parts that need to be protected or placed outside the parts. However, this type of material has high density, large overall mass, and high cost. Metal materials are easily oxidized and corroded by water vapor and oxygen in the air, which accelerates the wear rate of the shield, shortens the service life, and further increases the manufacturing cost. In addition, this kind of shield also has the disadvantages of poor processability, difficulty in adjusting shielding performance, poor absorbing performance, inconvenient use, and even easy to cause internal short circuit of precision instruments and equipment, which seriously limits the application of metal materials in the field of electromagnetic shielding. The preparation process of existing electromagnetic shielding composite materials is relatively complex and cumbersome, with many preparation steps, strict requirements on various operation steps, many types of materials required to prepare structures that meet shielding requirements, and high production costs. At the same time, the existing composite material preparation process cannot realize the rapid manufacture of a specific complex shielding structure, the production cycle is long, and the mechanical properties of the obtained composite material cannot meet the needs of various applications.

Continuous fiber composites have excellent properties such as high specific strength, high specific modulus, high temperature resistance, and low corrosion resistance. They have been widely used in various industries including aerospace, national defense, ships, construction, electronics, energy, and transportation. All industries have gradually become an indispensable material in human life. The resin-based composite material using conductive fiber as the reinforcing phase can produce an electromagnetic shielding body with excellent performance, which overcomes the shortcomings of low electrical conductivity of general composite materials, improves the shielding effect, and has the characteristics of excellent mechanical properties of composite materials. . At present, no relevant literature has been published.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method, the manufactured shielding structure not only has high shielding effectiveness (shielding effectiveness, SE), but also has a relatively high The low density also has the designability of electromagnetic shielding performance and mechanical properties, and the electromagnetic shielding performance of the shielding structure can be adjusted according to the needs of the application. At the same time, the continuous fiber composite material used has good mechanical properties.

To achieve the above object, the present invention adopts the following technical solutions:

A continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method, comprising the following steps:

1) Establish a three-dimensional model of the shielding structure: draw a three-dimensional model of the shielding structure of the continuous fiber composite material in the computer-aided design software CAD according to actual needs and combined with the actual shape of the required shielding parts;

2) Design conductive fiber path: According to the requirements of absorption attenuation (SEa), reflection loss (reflection attenuation, SEr) and overall shielding effectiveness (shielding effectiveness, SE) of the shielding structure, design and plan the conductive fiber inside the shielding structure In order to ensure the consistency of the fiber orientation of each layer inside the shielding structure, the "rectangular" fiber filling method is selected, and the angle θ between the fiber direction and the electric field strength direction E is changed to meet the requirements of the overall shielding effectiveness. The smaller the θ, the higher the shielding effectiveness; then use the computer-aided engineering software CAE to carry out preliminary simulation verification on the design results to ensure the use effect of the shielding structure;

3) Correction of 3D conductive fiber path: Due to the requirements of continuous fiber composite materials, the original sample needs to be printed in one stroke, and continuous and uninterrupted material extrusion printing should be carried out. Continuous printing should be performed within each layer and between layers. There should be no interruption of printing and no emptying of the nozzle, so as to create a shielding structure with uniform performance, and modify and plan the conductive fiber path in step 2) without affecting the shielding performance;

4) Generate shielding structure printing path: Import the 3D model established in step 1) into the computer-aided manufacturing software CAM, and select the scanning distance, layer thickness, The 3D printing process parameters of the printing speed, and the printing command file of the shielding structure is generated;

5) Prepare the shielding structure by 3D printing: connect the fused deposition modeling (FDM) composite 3D printer to the electronic computer, and import the printing order file obtained in step 4) into the CAM software; select the one that meets the conductivity requirements The thermoplastic organic polymer material is used as the matrix, and the appropriate conductive fiber is selected according to the requirements for shielding performance in step 2). After setting and adjusting the overall working conditions of the 3D printer, the additive manufacturing of the shielding structure is carried out, and finally the obtained shielding parts required.

The computer-aided design software CAD in the described step 1) includes Solidworks, 3D Studio Max, Unigraphics NX or CATIA.

The computer-aided engineering CAE software in the described step 2) includes COMSOL or CST MICROWAVE STUDIO.

The computer-aided manufacturing software CAM in the step 4) includes ReplicatorG, Skeinforge, Slic3r or Cura engine.

The thermoplastic organic polymer material in the step 5) includes polylactic acid (PLA), acrylonitrile-butadiene-styrene copolymer (ABS), polyetheretherketone (PEEK) or polyetherimide (PEI) And a composite thermoplastic organic polymer material with conductivity and magnetic substances mixed with graphene, conductive short fibers, and ferric oxide (Fe ₃ O ₄ ), the conductive fibers include carbon fibers, nickel-plated carbon fibers, plated Copper carbon fiber or copper wire.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1) Thermoplastic resin material is used as the matrix, and continuous fibers with good conductivity such as carbon fiber, metal-plated carbon fiber, and copper wire are used as reinforcements to form a continuous conductive path, which not only improves the conductivity of the shielding structure, but also ensures that the shielding mechanism has Excellent shielding effect, and reduce the density of the material;

2) It can achieve high-performance electromagnetic shielding effect under the condition of lower carbon fiber content;

3) The continuous fiber-reinforced resin-based composite material has excellent mechanical properties, so the shielding structure of the present invention also has a strong mechanical load-bearing capacity, and can be used as a structural part of electronic equipment, thereby realizing the manufacture of functional-structure integrated equipment and devices;

4) Utilizing the advantages of 3D printing manufacturing, it is possible to realize the rapid manufacture of shielding structures with specific and complex shapes;

5) Controllable design and manufacture of electromagnetic shielding effectiveness and mechanical properties can be achieved by changing the scanning distance of 3D printing, the thickness of a single layer, the type of conductive continuous fiber, the fiber metal coating material, and the thermoplastic resin matrix, and achieve the controllable structure of functional structure integration integrated design and manufacture.

Description of drawings

Fig. 1 is a schematic diagram of a three-dimensional model of an original sample in an embodiment of the present invention.

Fig. 2 is a schematic diagram of single-layer path distribution of conductive fibers with a shielding structure in an embodiment of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

A continuous fiber reinforced composite electromagnetic shielding structure 3D printing manufacturing method, comprising the following steps:

1) Establish a three-dimensional model of the shielding structure: Referring to Figure 1, according to the requirements for preparing the electromagnetic wave shielding performance test piece and the convenience of further preparation of the test piece, use the computer-aided design software CAD Solidworks to establish a 3D original sample of 45×45×5 Model, export the model as a file in stl format;

2) Design conductive fiber path: According to the requirements of absorption attenuation (SEa), reflection loss (reflection attenuation, SEr) and overall shielding effectiveness (shielding effectiveness, SE) of the shielding structure, design and plan the conductive fiber inside the shielding structure Referring to Figure 2, in order to ensure the consistency of the fiber orientation of each layer inside the shielding structure, the "rectangular" fiber filling method is selected, and the overall shielding effectiveness is satisfied by changing the angle θ between the fiber direction and the direction E of the electric field intensity It is required that the smaller the included angle θ is, the higher the shielding effectiveness is; in this example, in order to achieve a higher shielding effectiveness, θ=0 ^° is used, and then the design results are initially simulated and verified using the CSTMICROWAVE STUDIO of the computer-aided engineering software CAE to ensure the shielding The effect of using the structure;

3) Correction of 3D conductive fiber path: Due to the requirements of continuous fiber composite materials, the original sample needs to be printed in one stroke, and continuous and uninterrupted material extrusion printing should be carried out. Each layer and between layers should be printed continuously. There should be intermittent printing and idling of the nozzle, so as to create a shielding structure with uniform performance. Therefore, the conductive fiber path in step 2) needs to be reasonably modified and planned without affecting the shielding performance; refer to Figure 2. Design a "rectangular" printing path, and at the same time ensure that the direction of the fiber and the direction of the electric field strength E are 0 ^° . In order to meet the conditions for a single printing to be completed, if the printing of this layer starts from point A, and the printing of this layer ends at point B, Then the printing starting point of the next layer should be the printing end point B of this layer;

4) Generate shielding structure printing path: Import the stl 3D model established in step 1) into ReplicatorG of the computer-aided manufacturing software CAM, and according to the modified conductive fiber path in step 3), at the same time determine the fiber filling scanning distance of this 3D printing as 3D printing process parameters of 1.2mm, layer thickness of 0.5mm, and printing speed of 100mm/min, combined with computer-aided manufacturing software CAM slice software Skeinforge to generate the print command file of the shielding structure;

5) 3D printing to prepare the shielding structure: connect the fused deposition manufacturing (fused deposited manufacture, FDM) composite 3D printer to the computer, and import the printing order file obtained in step 4) into the CAM software; select polylactic acid (PLA) As the matrix, carbon fiber is selected as the conductive reinforcing fiber according to the shielding performance requirements in step 2), the overall working conditions of the 3D printer are set and adjusted, the additive manufacturing of the shielding structure is started, and finally the required shielding parts are obtained.

The shielding structure prepared in this example has been tested, and its shielding effectiveness is in the X-band (8.2-12.4GHz), with an average value of 60dB, while the fiber volume fraction is only 6.3%, and the mass fraction is 8.9%.

The present invention uses thermoplastic resin material as a matrix, and continuous fibers with good conductivity such as carbon fiber, metal-plated carbon fiber, and copper wire as a reinforcement to form a continuous conductive path, which not only improves the conductivity of the shielding structure, but also ensures that the shielding mechanism It has excellent shielding effect and reduces the density of the material. At the same time, high-performance electromagnetic shielding effect is achieved under the condition of low carbon fiber content. The continuous fiber-reinforced resin-based composite material has high mechanical properties, so the shielding structure of the present invention can also achieve a certain mechanical load-bearing function, and can be used as a structural part of an electronic device, thereby realizing the manufacture of functional-structure integrated equipment and devices. Utilizing the advantages of the 3D printing manufacturing process, the rapid manufacture of shielding structures with specific and complex shapes can be realized.

Claims (5)

1. A continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method is characterized in that, comprising the following steps: 1) Establish a three-dimensional model of the shielding structure: draw a three-dimensional model of the shielding structure of the continuous fiber composite material in the computer-aided design software CAD according to actual needs and combined with the actual shape of the required shielding parts; 2) Design conductive fiber path: According to the requirements of absorption attenuation (SEa), reflection loss (reflection attenuation, SEr) and overall shielding effectiveness (shielding effectiveness, SE) of the shielding structure, design and plan the conductive fiber inside the shielding structure In order to ensure the consistency of the fiber orientation of each layer inside the shielding structure, the "rectangular" fiber filling method is selected, and the angle θ between the fiber direction and the electric field strength direction E is changed to meet the requirements of the overall shielding effectiveness. The smaller the θ, the higher the shielding effectiveness; then use the computer-aided engineering software CAE to carry out preliminary simulation verification on the design results to ensure the use effect of the shielding structure; 3) Correction of 3D conductive fiber path: Due to the requirements of continuous fiber composite materials, the original sample needs to be printed in one stroke, and continuous and uninterrupted material extrusion printing should be carried out. Continuous printing should be performed within each layer and between layers. There should be no interruption of printing and no emptying of the nozzle, so as to create a shielding structure with uniform performance, and modify and plan the conductive fiber path in step 2) without affecting the shielding performance; 4) Generate shielding structure printing path: Import the 3D model established in step 1) into the computer-aided manufacturing software CAM, and select the scanning distance, layer thickness, The 3D printing process parameters of the printing speed, and the printing command file of the shielding structure is generated; 5) Prepare the shielding structure by 3D printing: connect the fused deposition modeling (FDM) composite 3D printer to the electronic computer, and import the printing order file obtained in step 4) into the CAM software; select the one that meets the conductivity requirements The thermoplastic organic polymer material is used as the matrix, and the appropriate conductive fiber is selected according to the requirements for shielding performance in step 2). After setting and adjusting the overall working conditions of the 3D printer, the additive manufacturing of the shielding structure is carried out, and finally the obtained shielding parts required. 2. A kind of continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method according to claim 1, is characterized in that: in described step 1), computer-aided design software CAD comprises Solidworks, 3D Studio Max, Unigraphics NX or CATIA. 3. A continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method according to claim 1, characterized in that: in the step 2), the computer-aided engineering CAE software includes COMSOL or CST MICROWAVESTUDIO. 4. A continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method according to claim 1, characterized in that: in the step 4), the computer-aided manufacturing software CAM includes ReplicatorG, Skeinforge, Slic3r or Cura engine. 5. A kind of continuous fiber reinforced composite material electromagnetic shielding structure 3D printing manufacturing method according to claim 1, is characterized in that: in described step 5), thermoplastic organic polymer material comprises polylactic acid (PLA), acrylonitrile- Butadiene-styrene copolymer (ABS), polyetheretherketone (PEEK) or polyetherimide (PEI) and mixed with graphene, conductive short fibers, iron tetraoxide (Fe ₃ O ₄ ) Composite thermoplastic organic polymer material with conductivity and magnetic substances, the conductive fibers include carbon fibers, nickel-plated carbon fibers, copper-plated carbon fibers or copper wires.