50 years of SIGRAFLEX® -
Unrivalled Sealing

With SIGRAFLEX you know what you get.
Safety. Quality. Reliability.

The SIGRAFLEX story begins in 1972 with the inauguration of our first flexible graphite foil line in Meitingen, Germany, and the SIGRAFLEX brand registration. Since then, our brand and products have conquered the world wherever safety, quality and reliability of the sealing materials are required.

From then to now, our SIGRAFLEX flexible graphite materials, SIGRAFLEX carbon and graphite yarns and, most importantly, our SIGRAFLEX people, make the difference by delivering the ultimate solutions for sealing and high temperature applications.

When buying SIGRAFLEX, our customers and the end users know what they get.

Opening ceremony of the first SIGRAFLEX production plant in Meitingen, Germany, 1972

Join us on our journey through the last five decades and read about the SIGRAFLEX history.

We will be adding more details and stories about all the milestones on this page throughout the year.
So be sure to come back!

Milestones in the 50 years of SIGRAFLEX

From the start, SIGRAFLEX established itself as the quality leader in the market of flexible graphite products. With our two production sites located in Meitingen, Germany and Valencia/CA, USA we ensure supply safety for our customers all around the world. Our SIGRAFLEX people always strive to provide products meeting the highest standards of long-term stability, quality, and safety and are pleased to share their technology expertise.

Over the course of the last 50 years, many new and innovative SIGRAFLEX products have set benchmarks for high-end graphite sealing solutions – from SIGRAFLEX UNIVERSAL to SIGRAFLEX HOCHDRUCK, followed by SIGRAFLEX MF® and SIGRAFLEX APX2® up to the TA-Luft compliant PRO variants and our SIGRAFLEX APX2 yarn.

Then and still today, SIGRAFLEX stands for Unrivalled Sealing.

  • The early days: Development of a new unique graphite material

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  • Official opening of first SIGRAFLEX® production plant
  • Registration of SIGRAFLEX® brand
  • New sealing material for difficult operating conditions

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  • SIGRAFLEX® portfolio grows and gains in relevance
  • First large-scale foil order comes from Japan

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  • SIGRAFLEX® NORMAL: First graphite gasket sheet with metal reinforcement

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  • Polycarbon Inc. becomes part of SIGRI

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  • SIGRAFLEX® STANDARD: First anti-stick graphite gasket sheet
  • Foundation of the Valencia site
  • SIGRAFLEX® UNIVERSAL: Reinforced gasket sheet with anti-stick coating

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  • Commissioning new 1,000 mm (39.4”) wide plant in Meitingen, Germany

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  • Start of production of 60“ (1,524 mm) wide foil line in Valencia, USA
  • SIGRAFLEX® HOCHDRUCK: Graphite gasket sheet meets highest demands for sealabilty and mechanics

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  • "Northridge" earthquake stops production in Valencia, USA, only for a short time:
    operations resume after only one month of downtime
  • Commissioning of 1,500 mm (59.1“) wide foil line in Meitingen, Germany
  • Granting of SIGRAFLEX® HOCHDRUCK patent
  • SIGRAFLEX® MF®: Gasket sheet for minimum leakage, best anti-stick behavior and safety
  • SIGRAFLEX® APX2® foil: Best-in-class temperature and oxidation resistance
  • Inauguration of 2nd production line in Meitingen, Germany
  • Great SIGRAFLEX team effort enables restart of production in foil manufacturing facility in Meitingen, Germany, just three months after a fire
  • SIGRAFLEX® APX2® HOCHDRUCK: Gasket sheet for high temperature applications
  • SIGRAFLEX® APX2® yarn: Maximum protection from oxidation
  • SIGRAFLEX®: High purity – best protection from flange corrosion
  • Coming soon: newest SIGRAFLEX® product innovation


World novelty SIGRAFLEX® HOCHDRUCK: Adhesive-free graphite gasket sheet with flat stainless-steel reinforcement for highest demands on tightness and mechanics

As early as the 1980ies, the tanged, impregnated graphite gasket sheet SIGRAFLEX® UNIVERSAL had already established itself on the market - as a high-performance product for sealing pipelines and vessels in chemical, petrochemical and power plants, among others.

However, for applications requiring thinner gaskets, used e. g. in valves and pumps, the market at that time also asked for flat steel reinforced graphite sheets. These also have the advantage of being easier to process.

In 1991, SIGRI launched SIGRAFLEX ECONOMY, the first flat stainless-steel reinforced, bonded gasket sheet, which, like UNIVERSAL, is still state-of-the-art today and an important part of our portfolio.

In the next step, the SIGRAFLEX R&D team, led by Alfred Hirschvogel, worked on developing a layer bond between graphite and steel in which the adhesive does not lead to a reduction of the maximum permissible gasket stress.

Silvia Mechen in particular concentrated on this task and, after many test series, was finally able to announce success in 1993: The new unique SIGRAFLEX HOCHDRUCK technology was born!

It creates a high-strength adhesive-free layer bond of highly pure graphite and stainless-steel foils. HOCHDRUCK sheets are rated to 250 bar (3625 psi) and meet the most stringent leak-tightness demands. The flat gaskets are also extremely safe and reliable. HOCHDRUCK is still one of the top products in our portfolio and continues to deliver what its name promises.

Throughout the 1980s and 1990s, SIGRI's engineers not only worked to create new products with other unique features, but also to further develop existing products in order to offer customers even better performance and service.

A major step was taken with the successful development of a process for sheet printing. In addition, a color logic was defined specifically for this purpose: Each SIGRAFLEX sheet is printed with a different color and also the exact sheet type and can thus be clearly identified. This enables end customers to avoid the use of wrong materials and thus to better prevent accidents.

The 1990s saw changes not only in SIGRAFLEX products but also at SIGRI. Through numerous acquisitions and investments, the company had developed into a group of companies, the SIGRI Group, since 1967. At the beginning of 1989, Hoechst AG took over the group completely.

Hoechst strived for making the SIGRI business more global and gaining more market power. On February 6, 1992, a merger with the U.S. company Great Lakes Carbon Corp. took place: the birth of the newly founded company Sigri Great Lakes Carbon GmbH - SGL Carbon for short - was announced.


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