Flexible Graphite Sheet: Properties, Benefits and Industrial Applications

1.Temperature resistance: the widest temperature span in the sealing material

• In the air (oxidizing atmosphere): -200 ℃~450 ℃, long-term stable
• Steam medium: up to 650 ℃
• Inert/reducing/vacuum atmosphere: up to 3000 ℃
• Thermal shock resistance: no cracking, softening, or melting during rapid cooling and heating

2.Sealing and Mechanics: Soft but Capable of Sealing

Typical industrial grade parameters:

• Density: 1.0-1.3 g/cm ³ (sealing grade), thermal conductivity grade can reach 1.5-1.8 g/cm ³
• Tensile strength: Machine direction 4.0-7.0 MPa
• Compression ratio: 35-50%
• Rebound rate: 15-25%
• Creep relaxation: Low, the sealing force attenuation after long-term compression is much smaller than that of fiber pads
• Gas permeability: extremely low, can achieve<10 ⁻⁴ cm ³/s

3.Thermal conductivity: obvious anisotropy

• In-plane thermal conductivity (XY): 150-500 W/m · K (high conductivity natural grade 300-600, ultra-high conductivity film 1000-1500)
• Vertical thermal conductivity (Z): 4-6 W/m · K
• So it is a uniformly heated material that spreads heat horizontally and does not transfer heat vertically, not a thick thermal pad

4.Chemistry and Physics

• Acid, alkali, solvent, oil, steam, seawater
• PH 1-14 universal
• Non asbestos, halogen-free, and adhesive free
• Self lubricating, friction coefficient 0.08-0.15
• Conductivity: Low in-plane resistance, suitable for grounding/EMI assistance
• Radiation stability: nuclear grade, aerospace usable

1.Industrial sealing

• Pipeline flange gasket (petrochemical, refining, fertilizer, fine chemical)
• Valve stem packing, pump casing seal, heat exchanger gasket
• Graphite packing ring for spiral wound pad
• Tooth shaped/clamped metal composite gasket
• Cylinder mattress, exhaust manifold gasket, diesel engine cylinder head gasket

2.Electricity and Energy

• Power plant steam pipelines, boiler manholes, turbine flanges
• Low sulfur and high-purity seals for nuclear power (to avoid bolt stress corrosion)
• High temperature buffer/isolation plate for single crystal furnace and polycrystalline ingot furnace
• Bipolar plate substrates for flow batteries and hydrogen fuel cells

3.Electronic heat dissipation and thermal management

• 0.03-0.2mm ultra-thin thermal conductive graphite paper: for mobile phones, 5G modules IGBT,LED, Laptop is uniformly hot
• 0.1-0.2mm natural graphite foil: electric heating bed/tatami heating core with back attached uniform heating layer
• Semiconductor diffusion soldering/brazing: creating a "uniform heating+uniform pressure" interlayer
• Anti SiC reaction isolation layer between quartz crucible and graphite crucible

4.Metallurgy, kilns, aerospace

• Vacuum furnace door lining, heat treatment furnace uniform heating layer
• Rocket/Satellite Thermal Control and EMI Shielding
• High temperature mold demolding (self-lubricating+non stick)

5.Electricians and electrochemistry

• Cathode/current collector of electrolytic cell
• Supercapacitors, flexible current collectors for experimental cells
• Electric motor brushes, grounding plates, conductive pads

Flexible graphite sheet is not a "thin version of graphite", but a rare black thin sheet in industry that can be sealed, thermally conductive, and durable.
Thick sheets sell seals, thin sheets sell heat dissipation; Pure sheets are sold for their temperature resistance, while composite sheets are sold for their strength.
For customers, choosing flexible graphite sheets is not about "buying consumables", but about buying downtime, medium leakage, hot spot burning, and asbestos compliance risks together.