Page 6 - Design Criteria.qxd

® 7
Thermiculite ™
Exclusive to Flexitallic, Thermiculite sheet sealing materials are comprised of both chemically
and thermally exfoliated vermiculite reinforced with a metallic core. Vermiculite, a naturally
occurring mineral with a plate-like structure, demonstrates a much broader range of chemical
resistance than graphite but, more importantly, superior high temperature sealing characteris-
tics.
Graphite’s stress-loss due to oxidation effects has led to many examples of gasket fail-
ure. Independent testing indicated a temperature limit of 340°C (650°F) for continuous serv-
ice over 5 years. Thermiculite however is thermally stable and maintains its integrity even at
extreme temperatures, ensuring against thermal oxidation (see graph on page 8). Independent
testing at TTRL (Tightness, Testing, and Research Laboratory), Montreal illustrates
Thermiculite’s excellent sealing properties.
Thermiculite’s high temperature capabilities make it an ideal choice for use in tur-
bochargers and superchargers, diesel engine exhaust manifolds and oxidizing services in the
nitrogen fertilizer manufacturing process, steam service, and many more. In addition, users
with off-shore and seawater cooling applications will value Thermiculite’s resistance to gal-
vanic corrosion.
Thermiculite gaskets can be cut and installed using traditional methods: the modern
techniques of water jet and laser cutting are also applicable to Thermiculite.
Thermiculite benefits from a high technical specification which makes it suitable for use
even in demanding service conditions. A superb level of tightness is achieved even at 500°C
(930°F) and the product maintains its overall effectiveness up to at least 982°C (1800°F).
Thermiculite is not affected by oxidation.
Product Range
Thermiculite 815 - Reinforced with a tanged 316 stainless steel core. Thermiculite 815 con-
tains a low percentage of nitrile rubber binder. This rubber is cured using a sulfur-free curing
system.
Thermiculite 816 - Differs from Thermiculite 815 only in the type of rubber binder used. A
special grade of SBR is incorporated into Thermiculite 816 making it suitable for use in the
high temperature processes of photographic film manufacture where “film fogging” can occur
with other polymer types.
Welcome to the Next Generation of Sealing Technology