How to process high thermal conductivity natural graphite sheet?

High thermal conductivity graphite sheet is a new type of two-dimensional material for thermal conductivity and heat dissipation. Due to its excellent thermal shock resistance, low resistivity, high modulus, corrosion resistance, especially high thermal conductivity, low thermal expansion coefficient, and low density, it has attracted the attention of researchers at home and abroad in practical applications. It can be composite with materials such as metals, resins, ceramics, etc. to meet more design functions and needs. It is considered one of the most promising high-efficiency thermal management composite material reinforcements and an important material for electronic devices to break through the "heat dissipation" problem in the 5G era.

The main raw material for preparing thermal conductive natural graphite film is natural graphite flake, with a carbon content generally above 97%; The higher the carbon content, the higher the purity of the graphite film, the higher the degree of graphitization, and the higher the thermal conductivity of the graphite film. Natural graphite with a carbon content exceeding 99% is preferred as the raw material for production. The particle size of natural graphite is generally distributed between 20 and 80 mesh. If the particle size is too small, the expanded graphite after expansion will have a smaller diameter, which will be unfavorable for the final rolling into sheets; If the particle size is too large, the strength of the prepared graphite film product is too low, and the crystal structure is unstable. Most of the thermal conductive natural graphite film available on the market use expandable graphite as the raw material.

At present, the production process of expanded graphite is very mature in China. Qualified expanded graphite is transported to the hopper by a screw machine, and through processes such as expansion, cooling, separation, preloading, matte coating, edge cutting, cutting, and coiling, thermal conductive natural graphite film is obtained.

In the 5G era, with the increase in power consumption of electronic products and the upgrading of structural design, high thermal conductivity graphite films are gradually developing from traditional single-layer graphite films to composite graphite films, and the application of ultra thick graphite films is increasing; As the permeability of flexible displays increases, the bending resistance of graphite films becomes more important. The processing characteristics of PI film, such as easy graphitization and suitability for whole roll firing, are becoming increasingly important.