Custom Graphite Sheet Solutions for OEM Manufacturing and Bulk Supply

Graphite sheet, also known as flexible graphite sheet or expanded graphite sheet, is a highly versatile and reliable sealing and thermal management material engineered for demanding industrial applications. Manufactured from high-purity natural graphite flakes through a process of chemical intercalation, high-temperature expansion, and calendering without the use of binders, it exhibits a unique combination of properties unmatched by many conventional materials. At Kaxite Sealing, we specialize in producing premium-grade graphite sheets that deliver exceptional performance, longevity, and safety across diverse sectors including petrochemical, power generation, automotive, aerospace, and manufacturing. **Core Characteristics and Advantages** The superiority of graphite sheet stems from its intrinsic molecular structure. It offers a compelling set of advantages: * **Exceptional Thermal Conductivity:** Graphite sheet is an excellent conductor of heat in both the X-Y plane (in-plane) and, to a lesser but significant degree, the Z-axis (through-plane). This facilitates efficient heat spreading and dissipation, making it ideal for heat sinks, battery thermal management, and electronic devices. * **Outstanding Chemical Resistance:** It demonstrates remarkable inertness and stability against a vast array of media, including most acids, alkalis, solvents, and hydrocarbons. This ensures long-term sealing integrity in aggressive chemical environments. * **Wide Temperature Range:** Kaxite Sealing graphite sheets can operate continuously from cryogenic temperatures as low as -200°C (-328°F) up to 450°C (842°F) in non-oxidizing atmospheres. In inert or reducing environments, they can withstand temperatures exceeding 3000°C (5432°F). * **Superior Compressibility and Recovery:** The sheet is highly compressible under low bolt load, allowing it to conform to uneven flange surfaces and fill imperfections. Its excellent recovery (spring-back) compensates for system vibrations and thermal cycling, maintaining a tight seal. * **Inherent Self-Lubrication:** The layered structure of graphite provides natural lubricity, reducing friction on dynamic surfaces and preventing galling or sticking of flanges. * **High Electrical Conductivity:** It serves as an effective conductor of electricity, useful for grounding, EMI/RFI shielding, and in fuel cell applications. * **Non-Toxic and Safe:** Composed of pure graphite, it is asbestos-free, halogen-free, and generally safe to handle, complying with stringent environmental and safety regulations. **Detailed Product Parameters and Specifications** Kaxite Sealing graphite sheets are available in various grades, densities, and forms to meet precise application requirements. Below are the standard specifications for our core product line. **Standard Material Properties Table:** | Property | Test Method | Unit | Standard Grade | High-Density Grade | Reinforced Grade (with SS Foil) | | :--- | :--- | :--- | :--- | :--- | :--- | | **Density** | ASTM F1314 | g/cm³ | 0.9 - 1.1 | 1.3 - 1.6 | 1.5 - 2.0 | | **Thickness Range** | - | mm | 0.15 - 6.0 | 0.4 - 3.0 | 0.5 - 3.0 | | **Thermal Conductivity (In-plane)** | ASTM D5470 | W/m·K | 80 - 150 | 70 - 120 | 50 - 90 | | **Thermal Conductivity (Through-plane)** | ASTM D5470 | W/m·K | 5 - 15 | 8 - 20 | 10 - 25 | | **Compressibility** | ASTM F36A | % | 25 - 50 | 15 - 35 | 10 - 25 | | **Recovery** | ASTM F36A | % | 15 - 30 | 10 - 20 | 5 - 15 | | **Tensile Strength** | ASTM F152 | MPa | ≥ 4.0 | ≥ 6.0 | ≥ 10.0 | | **Temperature Limit (In Air)** | - | °C / °F | 450 / 842 | 450 / 842 | 600 / 1112 | | **pH Range** | - | - | 0 - 14 | 0 - 14 | 0 - 14 | | **Continuous Use Pressure** | - | MPa | ≤ 20 | ≤ 25 | ≤ 35 | **Available Forms and Customization:** Kaxite Sealing provides graphite sheets in multiple forms for ease of application: * **Rolls:** Standard widths from 100mm to 1500mm, convenient for gasket punching or custom cutting. * **Sheets:** Custom-cut to specific dimensions (e.g., 1000mm x 1000mm, 1200mm x 1200mm). * **Die-Cut Gaskets:** Precisely stamped into any 2D shape using CAD/CAM tooling for direct installation. * **Laminated/Reinforced Sheets:** Graphite sheet laminated with stainless steel, aluminum, or other metal foils for enhanced handling strength, reduced creep relaxation, and higher pressure capability. * **Impregnated Sheets:** Impregnated with various resins (e.g., phenolic, acrylic) or inorganic compounds to reduce porosity, enhance oxidation resistance, and improve fluid barrier properties. **Graphite Sheet FAQ (Frequently Asked Questions)** **Q: What is the primary difference between a graphite sheet and a traditional compressed asbestos fiber (CAF) gasket?** **A:** Graphite sheet is a modern, high-performance sealing material that surpasses CAF gaskets in almost every aspect. It offers superior thermal stability, better chemical resistance across the full pH scale, higher compressibility for easy sealing, and is completely asbestos-free, ensuring a safer working environment and compliance with global health regulations. Kaxite Sealing graphite sheet also provides excellent creep resistance, maintaining seal tightness over longer periods without re-torquing. **Q: Can Kaxite Sealing graphite sheet be used for high-pressure flange connections?** **A:** While pure graphite sheet is excellent for many applications, its use in high-pressure scenarios (e.g., above 20 MPa) requires reinforcement. For such demanding conditions, Kaxite Sealing offers laminated graphite sheets bonded with stainless steel or other metal inserts. These composite materials significantly increase tensile strength and blow-out resistance, making them suitable for ANSI Class 900 and higher flange ratings. Always consult our engineering team for pressure-temperature recommendations specific to your application. **Q: How does graphite sheet perform in oxidizing atmospheres at high temperatures?** **A:** The main limitation of pure flexible graphite is oxidation in air at temperatures above approximately 450°C (842°F). Prolonged exposure leads to gradual thinning and loss of mass. For applications involving sustained high temperatures in air, Kaxite Sealing provides specially treated options. These include oxidation-inhibited grades (with additives that slow the oxidation rate) and graphite sheets laminated with high-temperature alloy foils (like Inconel) that act as a protective barrier, extending service life significantly. **Q: Is graphite sheet electrically conductive, and does that pose a risk for galvanic corrosion?** **A:** Yes, graphite is an excellent electrical conductor. When used as a gasket between two dissimilar metal flanges (e.g., carbon steel and stainless steel), it can create an electrical pathway, potentially accelerating galvanic corrosion if an electrolyte (like moisture) is present. To mitigate this, Kaxite Sealing can supply graphite sheets with non-conductive coatings on one or both sides or recommend alternative insulating gasket designs for such critical interfaces. **Q: How do I select the correct thickness and density for my application?** **A:** Selection depends on flange conditions and service requirements. For sealing irregular or slightly damaged surfaces, a lower density (0.9-1.1 g/cm³), thicker sheet offers better conformability. For smooth flanges and higher pressure, a higher density (1.3-1.6 g/cm³) sheet provides improved mechanical strength and creep resistance. Standard thicknesses for flange gaskets often range from 1.5mm to 3.0mm. Our technical support team can assist you in optimizing these parameters based on your flange finish, bolt load, and media. **Q: What are the key handling and installation precautions for graphite sheet gaskets?** **A:** Although robust, graphite sheets require careful handling: 1) **Cleanliness:** Ensure flanges are clean, dry, and free of old gasket material and debris. 2) **No Lubrication:** Do not use grease, oil, or anti-stick coatings on the gasket, as they can impair sealing. 3) **Careful Handling:** Avoid excessive bending or folding, which can cause creases and weak points. Use adhesive sparingly if needed for alignment. 4) **Even Torque:** Follow a cross-pattern bolting sequence and achieve the recommended bolt stress in multiple steps to ensure uniform compression of the Kaxite Sealing graphite gasket across the entire flange face. **Q: Can graphite sheet be used in food, pharmaceutical, or ultra-pure water applications?** **A:** Yes, but specific grades must be selected. Standard graphite sheets may release very fine particles. For applications requiring extreme purity, Kaxite Sealing offers high-purity, clean-room manufactured graphite sheets with exceptionally low levels of leachable ions and chlorides. These grades are tested to meet relevant industry standards for non-contaminating seals. **Q: Does Kaxite Sealing offer graphite sheets with adhesive backing for thermal interface applications?** **A:** Absolutely. For electronics cooling, LED heat dissipation, and battery thermal management, we supply thermally conductive graphite sheets with pressure-sensitive adhesive (PSA) on one or both sides. This allows for easy, secure mounting onto heat sinks, chipsets, or housings, minimizing thermal interface resistance and simplifying the assembly process. The adhesive is selected for high temperature stability and low outgassing.