Graphite Sheet

What is Graphite sheet?

Graphite sheet is a composite material, its main component is graphite, mainly used for thermal management. It has excellent thermal and electrical conductivity. Meanwhile it have outstanding flexibility and lightweight. Most graphite sheets are divided into natural graphite and synthetic graphite.

Type of Graphite sheets

There are so many different types of graphite sheets, and different categories for different field :

 Synthetic Graphite Sheet: made by elevated temperature graphitization process, it possesses highly pure and consistent quality. It makes synthetic graphite sheet especially suitable for electronic field, because reliable thermal conductivity and low impurity content is the most significant factor in this field.

 Reinforced Graphite Sheet: Those sheets add more materials such as stainless steel or metal mesh than the others to boost mechanical strength and compressive performance. Reinforced Graphite Sheet used in high mechanical stress environments in general, which need more flexibility and strength with sealing applications.

 Flexible Graphite Sheet: As the name suggests, flexible graphite sheet extremely flexible in order to adapt to various shapes and surfaces, to make it has highly effective in gaskets and seals. It’s widely used on irregular surfaces or gaps, because they can effectively ensure sealing and thermal management.

 Pyrolytic Graphite Sheet: It made by chemical vapor deposition (CVD), that means Pyrolytic Graphite Sheet possesses highly ordered structures and extremely thermal conductivity. Because of high thermal conductivity and purity,  it commonly used in premium applications, to display its excellent performance.

Pure Graphite Sheets: It made by pure graphite with free of any fillers or binders. Due to its unique properties, pure graphite sheets are used in applications with high purity, such as laboratories and sensitive electronics devices which need contaminants-free materials.

Graphite Foil Sheet: by processing Expanded graphite, to thinner and more flexible sheet, in general, used as high temperature gaskets or thermal barrier which fields with high requirements for elevated temperature.

Manufacturing process

There are two main methods to manufacture graphite, mechanical and chemical processes. It depends on required types and application needs:

Mechanical processing: by specific machine compress expanded graphite to form sheets of specific thickness and density. Mechanical processing is commonly used to produce flexible graphite sheets, to retain the natural layered structure of graphite, and keep flexibility.

Chemical Treatment: in this way, especially chemical vapor deposition (CVD), to produce Pyrolytic Graphite Sheet. In this process, carbon atoms will deposit layer by layer, to form a highly ordered structure. So it can provide excellent thermal conductivity and purity.

プロパティ

Physical Properties:

Morphology and structure: Graphite sheets possess layered structures, that means strong atomic bonds within layers and weaker interactions between layers. This structure make graphite possess flexibility, because each layers can slide, making the material to be shaped and conform to surfaces.

Thermal Conductivity: Graphite sheets have high thermal conductivity, in general, between 300 and 1500 W/mk, enabling efficient heat transfer. This property play a significant role in electronic applications where heat must be dissipated quickly.

Electrical conductivity: Owing to the free electrons in the graphite structure, make graphite sheets possess incredible electrical conductivity. In some special applications, like 熱伝導率 and electrical conductivity, this property is very alignment.

Processability: graphite sheets can be cut, shaped and laminated easily, and thickness can range from 0.05 to 1. m. This processability is needed in the electronics and automotive industries where precise assembly is required.

Chemical Property:

Thermal Stability: Graphite sheets can maintain structure integrity under high temperatures. Otherwise, in an oxygen-free environment, graphite sheets thermal stability can reach 400 degrees Celsius, making them very suitable for high temperature applications.

Chemical stability: graphite sheets are resistant to most chemicals, such as acids and bases. It can ensure graphite sheet durability in corrosive environments, moreover, extending their lifespan.

Other Chemical Properties: graphite sheet have low permeability to gases and liquids, it makes them effective in industrial applications as seals and gaskets.

アプリケーション

Owing to its unique properties, graphite sheets have a wide range of applications. There are six common applications:

Electronic products: graphite sheets are widely used in the smartphone’s , tablet’s and laptop’s thermal management. By efficiently conducting and dissipating heat, it can help and prevent devices overheating, thereby enhancing the performance and extending lifespan.

Automotive: in the contemporary vehicle, electric vehicles, graphite sheets are used for thermal management in battery packs and electronic modules. It can enhances battery performance and safety by effective thermal management. This is really important to development for electric and hybrid vehicles.

Aerospace: Graphite sheets provide thermal protection for spacecraft, satellites, and aircraft in the aerospace field. Due to its high thermal stability and lightweight characteristics, it really suits for critical aerospace components which have stringent requirements for high temperature resistance.

Industrial Machinery: Graphite sheets always used in high temperature and high pressure environments as gaskets and seals. In the particular field, where  durability and reliability play a important role. It commonly used for instance, chemical processing, power generation and other industrial machinery.

LED Lighting: in LED systems, they are used for heat dissipation, in order to help the machine to maintain optimal operating conditions and extended lifespan.

Medical Equipment: in medical equipment, which required precise thermal management, graphite sheets also irreplaceable. For example, imaging equipment and other sensitive temperature diagnostic devices. It can keep the temperature stable to ensure device reliability and performance.