Expandable graphite powder
Expandable graphite powder is a functional graphite material engineered for fire protection, thermal insulation, and sealing applications, where controlled expansion and reliable performance are essential. Supplied in clearly defined grades, it allows customers to select and order quickly based on expansion ratio and particle size.
Product Description
Expandable graphite powder is produced by treating natural flake graphite with intercalation compounds, followed by controlled processing and drying. When exposed to high temperatures (typically above 150–300°C), the material rapidly expands in the direction perpendicular to the graphite layers, forming a low-density, worm-like char structure.
This expansion behavior is the core value of the product. In real applications, it acts as a physical barrier against heat, flame, and gas diffusion rather than relying on chemical flame retardants.
Core Functional Principle
When heated, expandable graphite powder:
Expands 100–300+ times its original volume
Forms an insulating, intumescent carbon layer
Blocks oxygen, heat transfer, and flame spread
This process is fast, predictable, and does not release halogenated gases, which is why expandable graphite is increasingly used in halogen-free fire protection systems.
Standard Specifications (Ordering-Friendly)
Expansion Ratio (Key Selection Factor)
Common expansion grades include:
150 ml/g – general fire-retardant applications
200 ml/g – balanced expansion and stability
250–300 ml/g – high-performance fire protection
Higher expansion ratios generally provide better insulation but may reduce mechanical strength in composites.
Particle Size Options
+50 mesh
+80 mesh
+100 mesh
-100 mesh / fine grades
Particle size selection depends on dispersion requirements and application thickness.
Typical Technical Parameters
| Property | Typical Range |
|---|---|
| Fixed Carbon | ≥ 95% |
| Expansion Temperature | 150–300°C |
| Expansion Volume | 150–300 ml/g |
| Moisture | ≤ 0.5% |
| Appearance | Black / dark gray powder |
Exact values depend on grade; COA provided with shipment.
Key Product Advantages
Effective Fire Retardancy
Expandable graphite powder delivers physical flame resistance by forming a protective char layer. Unlike traditional additives, it does not melt or drip under heat, improving fire safety performance in passive protection systems.
Halogen-Free and Environmentally Friendly
The material supports compliance with modern environmental and safety regulations. It is widely used as an alternative to brominated or chlorinated flame retardants.
Thermal and Chemical Stability
Expanded graphite remains stable at high temperatures and resists most acids and alkalis, making it suitable for harsh industrial environments.
Compatibility with Multiple Systems
Expandable graphite powder can be incorporated into:
Polymers and rubber
Intumescent coatings
Sealing and gasketing materials
Construction and insulation products
Typical Applications
Fire-Retardant Plastics and Rubber
Used in cables, pipes, profiles, and molded parts to improve fire resistance and smoke suppression.
Intumescent Coatings
Applied in fireproof coatings for steel structures, tunnels, and buildings to create an insulating layer during fire exposure.
Sealing and Gasket Materials
Used in fire-resistant gaskets, expansion joints, and sealing systems where high-temperature expansion is required.
Construction Materials
Added to boards, panels, and insulation systems to enhance passive fire protection.
Packaging and Supply Options
Expandable graphite powder is available in:
25 kg moisture-resistant bags
500 kg / 1,000 kg jumbo bags
Custom packaging upon request
Proper sealing is used to prevent moisture absorption during transport and storage.