Flexitallic Thermiculite® 866

This produces a dispersion of individual platelets which are separated from each other. These platelets are highly flexible and conform to the surfaces of other particlesto bind them together. This binding action allows a sheet material to be manufactured without any organic binding agents being present, thus Thermiculite® 866 consists just of thechemically exfoliated vermiculite and a second filler material.

The second filler material is a very familiar mineral, talc, also known as steatite or soapstone. Like mica and vermiculite, steatite is also a naturally occurring, high temperature stable, sheet silicate mineral but it is characterized in that it is very soft. The combination of the chemically exfoliated vermiculite with steatite results in a material that retains all the chemical and thermal durability but which is very soft and conformable.

The softness of the material and the platelet alignment result in a material which compresses under very low load to produce a compacted material that offers a very tortuous, passage stopping, path to any gas trying to permeate through it in the plane of the sheet or perpendicular to that plane. This means that the material has superb sealing characteristics combined with peerless thermal stability.

A gasket must first create a seal and must then maintain that seal for the required lifetime. Thermiculite® 866 is excellent in both of these respects. It is soft and highly conformable and therefore creation of both macro and micro sealing is readily achieved. Also, maintaining the seal is not a problem as it
contains no organic components that would result in relaxation or creep and, in a connection stressed by bolts, lead to loss of surface load on the gasket.

Until Thermiculite® 866 has been raised to 570oC or more for the first time it has poor water resistance so care should be taken to ensure that in areas where condensed water is likely to be present that no part of the gasket that is not compressed protrudes into the area where that water is likely to be present.