The graphite is made of natural flake graphite,after oxide intercalation, the thermal expansion, compression molding. Graphite sheet is one kind of flexible graphite,and it’s invented in 1963. after that,it’s widely used in The United Kingdom,German,Franch and Japan.
The natural flake graphite is rich in China,and it’s our advantage to do the research and development on the graphite sheet.
The production method of graphite sheet:
Graphite is belong to the hexagonal crystal system,and it has a laminated structure,the Interlayer bonding force is very weak,so we could insert some Molecules and atoms into the interlamination by oxidation,and intermetallic compounds is formed, meanwhile expanding the spacing of layers at this step.then heat to about 1000℃ instantly after water scrubbing the compounds,the compounds between the layers separate and by this way,graphite level was pulled,after these,the graphite particle expand dozens of time rapidly along the C direction,it looks like worm under the microscope,so it’s called vermicular graphite,and also called expanded graphite,it has a great compressibility and resilience.under the pressure of mechanical force,the expanded graphite is molded,it could be put into a mould to molded or roller compaction by roll crushing mill.then the flexible graphite sheet is finished,it could form a plate or coil.
The flexible graphite sheet has a good temperature tolerance, corrosion resistance, impermeability and compressibility.it widely used as Gasket and filler under the condition of high temperature and corrosive medium.the graphite sheet which has a high aeolotropism,is also used as heat insulation material and conductive material,because of the thermal conductivity and conductivity of X,Y direction much higher than the Z direction.