Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for producing graphite base composite material for electromagnetic shield

A composite material and graphite-based technology, applied in the direction of magnetic/electric field shielding, electrical components, etc., can solve problems such as complex processes, achieve simple preparation processes, improve electromagnetic shielding performance, and overcome difficulties in uniform distribution to the graphite matrix.

Inactive Publication Date: 2006-02-01
TSINGHUA UNIV
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This manufacturing method is more complex

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for producing graphite base composite material for electromagnetic shield
  • Method for producing graphite base composite material for electromagnetic shield
  • Method for producing graphite base composite material for electromagnetic shield

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) expandable graphite and ferrocene crystal powder with a mass ratio of 1.25: 1 are uniformly mixed by mechanical physics;

[0027] (2) Put the mixture into an atmosphere at 1000°C, and the expandable graphite will expand rapidly to obtain expanded graphite worms with magnetic particles attached;

[0028] (3) Press the obtained expanded graphite worms into a disc with a diameter of 16 mm and a thickness of about 1 mm in a mold.

[0029] The microscopic morphology of the prepared expanded graphite worms attached with magnetic particles is as follows: figure 1 As shown, it can be seen that the magnetic particles have been uniformly mixed into the worms of expanded graphite; the microscopic morphology of the disc sample manufactured by this method is as follows figure 2 Shown; The hysteresis loop of the disc sample is tested with a vibrating magnetometer (VSM, Lake Shore 7307), and the results are as follows image 3 As shown, it can be seen from the figure that the s...

Embodiment 2

[0031] (1) expandable graphite and ferrocene crystal powder with a mass ratio of 5: 1 are uniformly mixed by mechanical physics;

[0032] (2) Put the mixture into an atmosphere at 700°C, and the expandable graphite will expand rapidly to obtain expanded graphite worms with magnetic particles attached;

[0033] (3) Press the obtained expanded graphite worms into a disc with a diameter of 16 mm and a thickness of about 1 mm in a mold.

[0034] The electrical conductivity of the sample was tested by the van der Pauw method in the four-point probe method, and its volume resistivity was 1.39×10 -3 Ω·cm.

Embodiment 3

[0036] (1) expandable graphite and nickel hydroxide powder with a mass ratio of 2.5: 1 are mixed uniformly by mechanical physics;

[0037] (2) Put the mixture into an atmosphere at 1100°C, and the expandable graphite will expand rapidly to obtain expanded graphite worms with magnetic particles attached;

[0038] (3) Press the obtained expanded graphite worms into a disc with a diameter of 16 mm and a thickness of about 1 mm in a mold.

[0039] The electrical conductivity of the sample was tested by the van der Pauw method in the four-point probe method, and its volume resistivity was 0.962×10 -3 Ω cm, electromagnetic shielding performance see Figure 6 .

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
electrical resistivityaaaaaaaaaa
electrical resistivityaaaaaaaaaa
electrical resistivityaaaaaaaaaa
Login to View More

Abstract

The invention belongs to the technical area of the electromagnetic shielding material. First, the expandable graphite and the additive capable of generating the magnetic fine particles are mixed evenly by using the mechanical, physical method or the solution dissolving method. Then, in condition of temperature 700-1200 deg.C, making the graphite expand quickly so as to obtain the expanded graphitic worm with the magnetic fine particles. The expanded graphitic worm can be pressed in moulds to produce the products with needed shape. The invented technique is simple. The conductivity of the produced is better than the electric high molecular material. The magnetic performance is better than the plain flexible graphite. The electromagnetic shielding performance is improved markedly, especially, when the frequency is higher than 900 MHz.

Description

Technical field: [0001] The invention belongs to the technical field of electromagnetic shielding materials, and in particular relates to a preparation method of a graphite-based composite material used for electromagnetic shielding. Background technique: [0002] With the rapid development of the modern electronics industry and the sharp increase in the number of various commercial and household electronic products, electromagnetic wave interference has become a new public hazard. Especially with the development of miniaturization, integration, light weight and digitalization of electronic devices, various electronic devices are extremely vulnerable to external electromagnetic wave interference and cause malfunction, image disturbance, sound distortion, etc.; on the other hand, due to In consideration of reducing costs and facilitating large-scale industrial production, the housing material metal of electronic products has been replaced by a large number of plastics and sim...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H05K9/00C04B35/536
Inventor 康飞宇郑永平彭俊芳
Owner TSINGHUA UNIV