PTFE PolyTetraFluoroEthylene
PTFE
is the most chemical resistant plastic known. It offers useful mechanical
properties from cryogenic temperatures to over 500° F. Impact
strength is high, but tensile strength and wear resistance are low
compared to other engineering plastics. Coefficient of friction
is lower than almost any other material. "Slippery" surface
makes it difficult to make anything adhere. Use in corrosive or
high temperature applications.
PTFE
has become the material choice when looking for a unique combination
of properties to provide performance unmatched by any other polymer.
PTFE and PTFE with selected fillers offer the following exceptional
characteristics:
excellent
chemical resistance and exceeds that of all other thermoplastics
and elastomers. Thus the resistance to swelling is good in almost
all media
very wide service temperature range from -260°C to +260°C
PTFE still has some elasticity and therefore it can be used for
seals and constructional parts, for example, with liquefied gases.
Unsurpassed dielectric properties.The electrical insulating properties
are outstandingly good. They are almost independent of frequency,
temperature and weathering effects. High purity and inertness the
lowest coefficient of friction of any solid a broad range of mechanical
properties .Thermal expansion, like most plastics, is 10 times that
of metals. The thermal conductivity is low so that removal of heat
from bearings and from other moving seals can lead to problems The
material is not elastomeric but is hard like polyethylene.
For these reasons, elastomeric seals in assemblies cannot simply
be replaced by PTFE seals. With lip seals, provision must be made
for a constant additional contact pressure by use of springs or
by other means. PTFE is filled with graphite, glass fibers, bronze
and carbon to achieve special properties.
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