Thermiculite® 866 was designed for, and proven in, Solid Oxide Fuel Cell applications. The components of Thermiculite® 866 ensure that a seal is created and then maintained in service.
- Recognised as the material of choice to achieve high sealing efficiency by leading developers of SOFC
- Ensures that a seal is created and then the seal is maintained in service
- Extended lifetime performance
- No burn off of organic material at elevated temperature
- Sealing performance not reduced by thermal cycling
- Soft and compressible
- Easily cut into complex shapes and profiles
- Complex sealing arrangements are easily accommodated
- Currently operating in service units

ThermiculiteŽ 866 is a sealing material specifically designed as a compression seal for Solid Oxide Fuel Cells [SOFC]. It is proving to be very successful in a range of SOFC applications around the world.
ThermiculiteŽ 866 is a product utilising the ThermiculiteŽ technology, based upon the use of chemically exfoliated vermiculite, that has been developed by Flexitallic to produce a range of high performance, high temperature, patented, sealing materials for industrial sealing.
Vermiculite, a naturally occurring mineral is closely related to mica, a mineral noted for high temperature capability, high chemical resistance and an electrical insulation. Both mica and vermiculite occur naturally as flakes which consist of a stack of very many crystal plates where each crystal plate is nanometres thick. Those flakes of vermiculite, unlike those of mica, are able to be exfoliated so that the crystal plates separate from each other.
This exfoliation can be partly achieved by the application of heat, the result is then the well known form of vermiculite used in many everyday applications such as in gardening compost, as a thermal insulation material, as a packaging material and in fire prevention applications. However, the very thin crystal plates can be separated efficiently from each other by chemical means to produce a form which consists of just these very thin crystal plates.
The separated plates are highly flexible and have the most useful property of adhering to each other to produce a thin, flexible, film. If a second material is added to the chemically exfoliated vermiculite then the second material will be bound by the chemically exfoliated vermiculite without the need for the addition of a binder. This binding action of chemically exfoliated vermiculite means that when it is mixed with other, morphology compatible, materials that it is possible to make, by methods developed by Flexitallic, a very flexible sheet material. This sheet material, ThermiculiteŽ 866, is readily cut into gaskets of complex shapes.
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Thermiculite 866 performance figures Performance Of ThermiculiteŽ 866

The components of ThermiculiteŽ 866 ensure that a seal is created and then maintained in service. Consisting of highly aligned platelets of chemically exfoliated vermiculite binding other unique key ingredients ThermiculiteŽ 866 is very soft, resulting in a compressible and flexible material that is completely free of organic content.

Due to its unique chemical and physical properties, ThermiculiteŽ 866 is highly temperature resistant (1000°C) and, as there is no organic content, there is no burn off of volatile components at SOFC operational temperatures.

This ensures that during the lifetime of the fuel cell there is no increase in porosity and no additional leakage at elevated temperature. Figures 1 and 2 show that there is no difference in sealing performance at elevated temperature.

As there is no burn off of organic material at elevated temperature there is also no reduction in the gasket thickness at temperature and no resulting relaxation of the bolts.The seal is therefore stable during cycling between ambient and operational temperatures.

ThermiculiteŽ 866 provides excellent service performance. Figures 3 and 4 show stack results obtained by a customer and reproduced with their full permission.

For more information on Flexitallic SOFC, please contact us
The Flexitallic Group