Flexible graphite foil (sheet) is made from high purity, high crystalline natural graphite flakes, which are processed into expanded graphite crystals by a special acid and thermal treatment. The expanded graphite crystals are then formed into foil through an extensive calendaring process without any resins and binders.
These products have the characteristics of high temperature resistance, corrosion resistance, anti-irradiation and good elasticity. Working temperature is -200~650 °C (in air) and up to 3000 °C (in non oxidizing media).
Flexible graphite sheet or roll is the main raw material for making all kinds of graphite tapes, reinforced graphite sheets, sealing and packing gaskets, etc.
Available Types and its Main Properties
|
Thickness (mm)
|
Width
(mm)
|
Length
(m)
|
Density
(g/cm3)
|
|
Roll
|
Sheet
|
|
0.15 - 1.6
|
0.15 - 3.0
|
50 - 1500
|
1 - 200
|
0.7 - 1.5
|
|
Properties
|
NFO-A
|
NFO-B
|
NFO-C
|
NFO-D
|
|
Carbon content
|
≥99%
|
≥99%
|
≥99%
|
≥98%
|
|
Sulphur content (PPM)
|
≤500
|
≤1000
|
≤1300
|
≤1500
|
|
Chloride content (PPM)
|
≤35
|
≤40
|
≤45
|
≤50
|
|
Tensile strength (MPa)
|
≥4.2
|
≥4.0
|
≥3.8
|
≥3.6
|
|
Compressive rate
|
35 - 55% (density: 1.0 g/cm3)
|
|
Resilient rate
|
≥10% (density: 1.0 g/cm3)
|
|
Ash content
|
≤1%
|
|
Tolerance of thickness (mm)
|
thickness <1mm±0.03, 1-1.5mm±0.05, >1.5mm±0.1
|
|
Tolerance of density (g/cm3)
|
±0.05
|
±0.05
|
±0.06
|
±0.07
|
|
Working temperature (°C)
|
-200 ^ 650 °C (in air)
-200 ^ 3000 °C (in non-oxidizing medium)
|
The above technical indexes, including trace elements contents, can be adjusted according to user's special requirements
Characteristics and Benefits
- Excellent thermal stability and reflectivity
- High chemical resistance and chemical stability. Resistant to fluids with pH range of 0-14 (except strong oxidizers such as nitric or sulphuric acid)
- High purity – eliminates potential fluid contamination, ideal material for nuclear applications
- Low coefficient of friction – highly self-lubricating materials
- Asbestos free – no associated health hazards
- Highly anisotropic - the electrical and thermal conductivity characteristics are very different to in the direction parallel to and perpendicular to flakes
- Low electrical resistivity
- High thermal conductivity
- Ideal materials for sealing due to flexibility and resilience to fit other materials
Applications
- Being widely used in kinetic and static sealing for machine, pipe pump and valve in power industry, oil industry, chemical industry, light industry as well as machinery industry. It is an ideal new type of sealing material which can replace traditional sealing material such as rubber or fluorated plastics and asbestos, etc
- Automotive gaskets
- Packing materials for chemical plants
- For furnace insulators (graphite foil is an excellent reflector and provides gas erosion protection for hot zones)
- High-purity furnace parts
- Spacers for making semiconductors
- Heat dissipation graphite sheet
