English
Cork sheet, derived from the bark of the cork oak tree (Quercus suber), is a remarkable natural material renowned for its unique cellular structure. This structure grants it an exceptional combination of properties: it's lightweight, compressible, resilient, buoyant, impermeable to liquids and gases, and provides excellent thermal and acoustic insulation. As a sustainable and renewable resource—the bark regenerates every 9-12 years without harming the tree—cork has become a preferred material across numerous industries, from construction and automotive to aerospace and consumer goods.
Kaxite Seals specializes in providing premium-grade cork sheet products, engineered to meet the most demanding specifications. Our commitment to quality sourcing and precision manufacturing ensures that every sheet delivers consistent performance, durability, and environmental responsibility.
To select the right cork sheet for your application, understanding its technical parameters is crucial. Below is a detailed breakdown of the core specifications offered by Kaxite Seals.
| Parameter | Standard Range | Premium / High-Performance Range | Test Standard | Key Application Implication |
|---|---|---|---|---|
| Thickness | 0.5 mm - 6 mm | 6 mm - 50 mm (laminated) | ISO 7322 | Determines gasket compression, insulation depth, and vibration damping capability. |
| Density | 120 - 280 kg/m³ | 280 - 520 kg/m³ | ASTM D1622 | Higher density offers better mechanical strength and resistance to extrusion. |
| Tensile Strength | 0.8 - 1.2 MPa | 1.2 - 2.0 MPa | ASTM D1623 | Indicates resistance to tearing and pulling forces during handling and installation. |
| Compression Set (24h @ 70°C) | 25% - 40% | 15% - 25% | ASTM D395 | Lower percentage means better recovery and sealing longevity after compression. |
| Thermal Conductivity (k-value) | 0.040 - 0.045 W/(m·K) | 0.035 - 0.040 W/(m·K) | ISO 8301 | Excellent insulator; lower k-value signifies superior thermal insulation performance. |
| Max Continuous Service Temperature | 100°C (212°F) | 120°C (248°F) | - | Critical for engine, exhaust, or industrial applications to prevent degradation. |
| Water Absorption (24h immersion) | 15% - 25% by volume | 5% - 15% by volume | ASTM D570 | Lower absorption is vital for outdoor, marine, or high-humidity environments. |
| Flame Resistance | Class B (DIN 4102) | Class B1 / Low Flame Spread | DIN 4102 / UL 94 | Important for construction and transportation safety compliance. |
| Format | Standard Dimensions (Width x Length) | Thickness Tolerance | Cutting Options |
|---|---|---|---|
| Sheets / Rolls | 1000 mm x 1000 mm (39.4" x 39.4") 1250 mm x 2500 mm (49.2" x 98.4") Rolls: 1000 mm wide x 20 m long |
±0.2 mm (for <3mm) ±0.5 mm (for >3mm) |
Die-cut, kiss-cut, laser-cut, CNC router cut to precise shapes and gaskets. |
| Custom Blanks | As per customer drawing (max. 1500mm x 3000mm) | As per specification ±0.1mm achievable | Fully customizable for prototype or production runs. |
Q: What are the main advantages of using cork sheet over synthetic rubber or foam gaskets?
A: Cork sheet offers several distinct advantages. It is a 100% natural and renewable material, appealing to sustainable design goals. Its unique cellular structure provides natural compressibility and recovery, excellent vibration damping, and thermal/acoustic insulation in a single material. It is also resistant to many oils and fuels, which can degrade some synthetic rubbers. For static sealing applications with irregular surfaces, cork conforms exceptionally well, often outperforming harder synthetic materials.
Q: How do I choose the right density for my cork sheet application?
A: Density is a critical selector. For lightweight insulation, soundproofing panels, or bulletin boards, lower density (120-200 kg/m³) is ideal. For general-purpose gasketing in automotive oil pans, valve covers, or gearboxes, medium density (200-350 kg/m³) offers a good balance of compressibility and resistance. For high-pressure flange gaskets, heavy-duty machinery, or applications with high extrusion risk, specify high-density cork (350-520 kg/m³) from Kaxite Seals for maximum durability and minimal compression set.
Q: Can cork sheet be used in outdoor applications?
A: Yes, but with proper consideration. Natural cork is hydrophobic to a degree but will absorb moisture if constantly immersed. For outdoor use, such as expansion joints in construction, panel insulation, or marine decking, it is imperative to specify a cork sheet with a high-quality water-resistant binder and a lower water absorption rating. Kaxite Seals offers grades with water absorption below 10% by volume for such demanding environments. A protective finish or sealant can also be applied for extended longevity.
Q: What is the maximum temperature a cork gasket can withstand?
A: The maximum continuous service temperature for standard cork sheet with synthetic binders is typically 100-120°C (212-248°F). Short-term peaks can be slightly higher. Exceeding this temperature can cause the binder to degrade, leading to hardening, cracking, and loss of sealing force. For higher temperature applications, such as near exhaust systems, composite materials (like cork-and-rubber) or specialized high-temp binders are recommended. Always consult the technical data sheet for the specific grade.
Q: How is cork sheet manufactured, and what ensures its consistency?
A: At Kaxite Seals, the process begins with selecting and granulating cork bark. The granules are then carefully mixed with a binder in precise ratios. This mixture is spread into molds and subjected to controlled heat and pressure in a hydraulic press, curing the binder and forming solid sheets. Consistency is ensured through rigorous quality control: raw material inspection, precise control of granule size distribution, binder content, pressing temperature, pressure, and time. Every batch is tested for key parameters like density, tensile strength, and compression set.
Q: Is cork sheet resistant to chemicals, oils, and fuels?
A: Cork has good natural resistance to many common chemicals, including oils, greases, and fuels like gasoline and diesel. This makes it a traditional choice for automotive and industrial fluid systems. However, resistance is not universal. It is not recommended for use with strong acids, bases, solvents, or oxidizing agents. Always perform compatibility testing for your specific fluid media. Kaxite Seals can provide guidance and samples for testing based on your application's chemical environment.
Q: Can you supply custom-shaped gaskets and parts made from cork sheet?
A: Absolutely. A core service at Kaxite Seals is precision conversion. We can die-cut, kiss-cut, laser-cut, or CNC route cork sheet into any 2D shape with tight tolerances. This includes complex gaskets for engines, pumps, flanges, housings, and insulation pads for appliances or electronics. We work from your CAD drawings, samples, or specifications to deliver ready-to-install parts, reducing your production time and material waste.
Q: Why is cork considered an eco-friendly material?
A: Cork is one of the most sustainable materials available. Harvesting the bark does not harm the cork oak tree, which lives for 200-300 years and is harvested every 9-12 years. The process promotes carbon sequestration—cork forests are significant carbon sinks. The production of cork sheet typically uses less energy compared to synthetic alternatives. It is biodegradable and recyclable; off-cuts and end-of-life cork products can be re-granulated to make new composite materials, supporting a circular economy.
Kaxite Seals stands as a dedicated expert in engineered cork products. Our deep technical knowledge ensures you receive not just a material, but a solution tailored to your performance, environmental, and budgetary requirements. We control our supply chain from sustainable raw material sourcing to precision manufacturing and conversion, guaranteeing traceability and quality at every step. Our technical support team is available to help you select the optimal grade, thickness, and form for your specific application, ensuring reliability and longevity in your final product. We provide comprehensive material data sheets, samples for testing, and flexible supply options from standard sheets to custom-fabricated parts.
