SGL Carbon offers a broad range of SIGRAFLEX flexible graphite foil grades for different applications. They feature high reliability, even under extreme operating conditions. Thus, they are the first choice for sealing applications for long-term use at high temperatures.
Industrial manufacturing processes are becoming more and more complex, and more demanding on the materials used. In particular higher process temperatures, reductions in equipment downtimes, and increased product quality demand optimum material solutions. SIGRAFLEX foils made of expanded natural graphite support end users around the world in producing high quality products for safe processes.
Benefits and properties
- Long-term stability of compressibility and recovery over a wide temperature range
- Range of use from -269 °C (-452 °F) to approx. 3,000 °C (5,432 °F) depending on installation and operating conditions
- Low permeability to gases and liquids
- Absence of binders means no ageing or embrittlement
- High resistance to chemical media and radiation
Largest variety in the market
With our support, select exactly the product which most closely meets your requirements from the largest portfolio of flexible graphite foils and tapes in the world: For example, oxidation resistant, high-purity or industrial quality foils or grades that exhibit low friction characteristics.
Long-term stable mechanical behavior
All of our foils and foil tapes are distinguished by their long-term stability. This is a crucial benefit and stands in contrast to other materials exhibiting high flow characteristics which is detrimental to the long-term integrity of a joint seal. Even when surface stress reduces during operation, the sealing effect of SIGRAFLEX is largely maintained.
Processing of graphite foils and tapes
SIGRAFLEX flexible graphite foils and foil tapes have an outstanding workability and are particularly easy to cut, to press and to punch. They are processed into a wide range of products by using various methods.
Flexible graphite foil is found particularly in flat gaskets and as graphite outer layer for Kammprofile and corrugated gaskets, but also in high temperature processes as heating element, heat shield, release liner, protective liner and diffusion barrier.
Foil tapes are pressed to packing rings, wound into spiral wound gaskets, processed into foil yarns for braided packings or into corrugated tapes.
Application-specific suitability of our SIGRAFLEX flexible graphite foils
We offer the best flexible graphite foil for your individual application.
|Chemical and petrochemical||Spiral wound gaskets||●||●||●||●||●||●||●||●|
|Power generation||Spiral wound gaskets||●||●||●||●||●||●||●||●|
|Refining||Spiral wound gaskets||●||●||●||●||●||●|
|Automotive||Gaskets in exhaust system||●||●||●||●|
|Cylinder head gaskets||●||●||●||●||●|
SIGRAFLEX oxidation resistant flexible graphite foils
SIGRAFLEX flexible graphite foils and foil tapes made of expanded natural graphite are distinguished by their high temperature resistance. They are the first choice in sealing applications for long-term use at high temperatures.
Compared to other industrial graphite foils, our types SIGRAFLEX APX2, BP, AP, APX and E exhibit remarkable oxidation resistance. Their typical weight loss (in TGA test in air at 670 °C (1,238 °F) for four hours) is at 2% per hour and less, while conventional industry foils lose up to 40%.
When it comes to corrosion protection, SGL Carbon offers the widest-ranging portfolio on the market. With their low sulfur and halogen content, our foils fulfill user specifications and are genuine high performers in system protection.
Material data of our SIGRAFLEX oxidation resistant flexible graphite foils
|Thickness||mm||0.25 - 1.52||0.25 - 3.05||0.25 - 2.0||0.35 - 1.0||0.35 - 1.0|
|in||0.01 - 0.06||0.01 - 0.12||0.01 - 0.08||0.014 - 0.04||0.014 - 0.04|
|Purity||%||≥ 98||≥ 98||≥ 98||≥ 98||≥ 99|
|Ash content||%||≤ 2||≤ 2||≤ 2||≤ 2||≤ 1|
|Density||g/cm3||1.0 - 1.12||0.7 - 1.43||1.0 - 1.12||0.7 - 1.3||0.7 - 1.3|
|Sulfur content||ppm||< 300||< 300||< 300||< 300||< 300|
|Chloride content||ppm||≤ 25||≤ 50||≤ 50||≤ 25||≤ 10|
|Weight loss in air at 670°C/1238°F (TGA)1)||%/h||≤ 1||≤ 2||≤ 2||≤ 3||< 4|
SIGRAFLEX high-purity flexible graphite foils
SIGRAFLEX flexible graphite foils are manufactured without the use of adhesives and binders. We use high-purity natural graphite flakes as our base material. This minimizes contamination which significantly reduces the leakage rate, as well as the thermal and corrosion resistance of graphite gaskets and steel flanges.
Thanks to its very high-purity SIGRAFLEX foils make a significant contribution to protecting adjoining components from corrosion. This increases the operating reliability and the entire service life of equipment. Our products contribute significantly to cutting costs in static and dynamic sealing connections, piping, pumps, fittings, and vessels. Our high-purity foils are especially suited to extreme requirements, such as sensitive processes in power plants.
Material data of our high-purity SIGRAFLEX flexible graphite foils
|Thickness||mm||0.25 - 1.52||0.15 - 3.0||0.37||0.25 - 1.52|
|in||0.01 - 0.06||0.006 - 0.12||0.015||0.01 - 0.06|
|Purity||%||≥ 99.5||≥ 99.85||approx. 98||> 99|
|Ash content||%||≤ 0.5||≤ 0.15||approx. 2||< 1|
|Density||g/cm3||0.7 - 1.12||0.7 - 1.3||0.95||1.12|
|Sulfur content||ppm||< 300||< 300||< 300||< 300|
|Chloride content||ppm||≤ 50||≤ 10||≤ 20||≤ 10|
SIGRAFLEX industrial quality flexible graphite foils
Our SIGRAFLEX industrial quality foils boast outstanding sealing properties. They are compressible and easy to shape and fit well against the surface to be sealed, even on uneven surfaces, a clear advantage over other sealing materials.
Material data of our SIGRAFLEX flexible graphite foils in industrial quality
|Thickness||mm||0.35 - 3.0||0.25 - 3.0|
|in||0.014 - 0.12||0.01 - 0.12|
|Purity||%||≥ 98||≥ 98|
|Ash content||%||≤ 2||≤ 2|
|Density||g/cm3||0.7 - 1.3||0.7 - 1.4|
|Sulfur content||ppm||< 300||< 500|
|Chloride content||ppm||≤ 25||≤ 50|
Brochures, technical data and information sheets as well as approvals and test reports on our SIGRAFLEX products can be found in our Download Center.