Graphite Felt
Carbon Content: Over 99%.
Dimensions: Available in various customizable widths and thicknesses, generally 3mm, 5mm, 10mm, etc., sold by roll.
Temperature Resistance: Over 2000 degrees Celsius.
Usage: All soft felts can be easily cut with knives and scissors, allowing easy adjustment to the desired shape.
Graphite felt is a composite material with excellent thermal conductivity, sound insulation, and thermal insulation properties. It is made from a mixture of graphite fibers and a small amount of inorganic fibers, with a special coating on the surface of the graphite fibers that provides wear resistance and corrosion resistance. Graphite felt is elastic, foldable, and can be cut at will. It can be sewn with graphite yarn and is mainly used as insulation and thermal insulation material for single-crystal silicon smelting furnaces.
Types of Graphite Felt
As a leading graphite electrode supplier, AGRM has nearly 20 years of experience in customizing graphite products, ensuring product dimensions within drawing tolerances. Please contact our engineers for more personalized solutions if you have any requirements.
Hard Graphite Felt
It has higher rigidity and strength, commonly used in applications requiring high structural integrity, such as structural components of high-temperature furnaces.
- Undergoes high-temperature graphitization and is compounded with a small amount of binder.
- Improves working environment and operability.
- Can be treated with different surface coatings to meet various application needs.
- The smoke emission rate was significantly reduced compared to soft felt, extending its service life.
Soft Graphite Felt
Soft and easy to form, suitable for applications requiring flexibility and deformability, such as sealing materials and thermal pads.
- Flexible insulation material entirely made of carbon fibers.
- Suitable for high-temperature applications in inert or vacuum environments.
- Used as insulation in high-temperature industrial furnaces and can be tied and sewn with specially woven carbon ropes.
- Features controllable internal structure and conductivity.
- Suitable for energy storage applications like redox flow batteries.
- Insulation :
Soft felt > Hard felt
- Service Life :
Hard felt > Soft felt
- Thermal Conductivity :
Hard felt > Soft felt
1. Different Strength And Hardness
Hard graphite felt has higher strength and hardness, suitable for applications requiring higher pressure and rigidity, while soft graphite felt has lower strength and hardness.
2.Different Water Absorption and Softness
Soft graphite felt has better water absorption and softness, suitable for applications requiring better adsorption and softness, while hard graphite felt has poorer water absorption and softness.
Graphite Felt Specifications
Material | Graphite Rigid Felt(Pan-based) | Graphite Rigid Felt(Pan-based) | Graphite Rigid Felt(Rayon-based) | |
| Bulk Density | g/cm3 | 0.17 | 0.2 | 0.15-0.17 |
| Compressive Strength | MPa | 0.3 | 0.35 | 0.25 |
| Thermal Conductivity (@1000℃) | W/(m.k) | 0.35 | 0.43 | 0.2 |
| Ash | ppm | ≤200 | ≤200 | ≤200 |
| Maximum Operating Temperature | ℃ | 3000 | 3000 | 2400 |
| Maximum Size | mm | Sheet: 2800×2100×300; Cylinder: φ1800/φ1400×1800 | ||
| Surface Treatment | We can provide various processing methods for graphite rigid felt according to the needs of users, including applying hardened coatings, attaching graphite paper, pasting carbon cloth, and attaching C/C plates. | |||
| Grade | TSF1-01 | TSF3-01 | |
| Material | Graphite Soft Felt(Pan-based) | Graphite Soft Felt(Rayon-based) | |
| Bulk Density | g/cm³ | 0.13 | 0.1 |
| Thermal Conductivity (@1000℃) | W/(m.k) | 0.24 | 0.15 |
| Ash | ppm | ≤500 | ≤200 |
| The Maximum Operating Temperature | ℃ | 3000 | 3000 |
| Maximum Size | mm | Width: 1600; Thickness: 5,10 | |
Graphite Felt Characteristics
- Flexible material, easy to cut and install
- Maximizes furnace performance and lifespan
- High purity, high heat resistance
- Low ash and sulfur content
- Minimizes energy consumption and cost
- Lower surface area and better oxidation resistance
- Low density, shrinkage, and thermal mass
- No outgassing
- High-quality material, soft to the touch
- 100% rayon-based fiber precursor
- Carbon content ≥ 99%
- Low gas generation and higher resistance to gas oxidation
Base Materials of Graphite Felt
PAN Graphite Felt
PAN graphite felt, also known as polyacrylonitrile, is designed for high-temperature insulation in vacuum and inert gas furnaces. Compared to rayon felt, PAN has larger fibers, a smaller surface area, and better oxidation resistance. The material undergoes heat treatment at temperatures up to 2200℃ (3992℉).
PAN is made from larger coarse fibers, resulting in a smaller surface area and better oxidation resistance. This flexible material is harder, and softer to the touch, but with excellent performance and lower cost. PAN graphite felt is the most widely used because it is easier to handle, performs well, and is more cost-effective compared to rayon graphite felt.
Rayon Graphite Felt
Rayon graphite felt is a premium material designed for high-temperature insulation in vacuum and inert gas furnaces and other applications. Compared to PAN graphite felt, rayon has higher carbon content and lower ash content. The material undergoes heat treatment at temperatures up to 2500℃ (4532℉).
Rayon felt is a premium soft insulation material made from 100% rayon fiber precursor. Compared to PAN, rayon undergoes high-temperature pre-baking, resulting in higher carbon content, lower ash content, and lower thermal conductivity. Use rayon graphite felt if lower ash content and thermal conductivity are required.
Graphite Felt Applications
- Thermal Insulation Material
Graphite felt has excellent high-temperature resistance and insulation properties. It can be used as a thermal insulation layer to prevent heat conduction or radiative heat transfer.
- Sealing Material
Due to its softness and plasticity, graphite felt can be used to make sealing gaskets or filler materials. It can provide effective sealing performance in high-pressure environments.
- Corrosion-resistant Material
Graphite felt has good corrosion resistance to various chemicals, making it suitable for anti-corrosion coatings, protective coverings, and acid-alkali-resistant equipment.
- Sound Insulation Material
Graphite felt provides good sound insulation effects, suitable for noise control and sound insulation applications. It can reduce the propagation and reflection of sound waves, lowering noise levels.
- Furnace insulation materials and components
- Insulation boards and heat sinks
- Welding pads
- Cathodes in flow battery applications
- Reaction surfaces for other electrochemical processes
- Glassblowing pads and plumbing pads
- Wicks in ultra-light furnaces
- Car exhaust liners
Manufacturing Process of Graphite Felt
- Mixing
Mix graphite powder and tar in a certain ratio to form a uniform mixture. Pay attention to the precision and mixing time, which vary for different graphite felt series.
- Compacting
Place the mixed material into a press and compact it with a certain pressure. Ensure even pressure distribution during compacting to avoid uneven hardness. Compacting thickness is a crucial parameter. Generally, to ensure the density of graphite felt, the compacting thickness should be greater than 50%.
- Drying
Dry the compacted graphite felt at room temperature for 24 hours to ensure complete drying.
- Baking
Place the dried graphite felt in a baking furnace for high-temperature baking. The temperature and time of baking play a decisive role in the performance and quality of the graphite felt. Generally, the baking temperature for graphite felt is 1100-3000℃, and the baking time ranges from several hours to several tens of hours.
- Post-processing
Perform post-processing such as drilling, cutting, and aluminum coating on the graphite felt as needed to form the desired product.
