Polytetrafluoroethylene
In 1938,
polytetrafluoroethylene (PTFE) was discovered
unexpectedly when a cylinder in which the monomer
had been stored under pressure was cut open.
Pilot scale production commenced in the USA in
1943 and the material was commercially introduced
there and in the UK in 1948. Although PTFE is
classed as a thermoplastic, it is not processed
by conventional moulding or extrusion but by
sintering PTFE powder compacted to the required
shape under pressure. Applications generally
exploit one or more of its unusual combination of
properties; resistance to high temperatures,
resistance to low temperatures, low loss
dielectric properties over a wide frequency range,
chemical inertness and antistick properties.
The most well-known examples of its use include
non-stick cookware (non-stick Teflon coated
frying pans were introduced for Christmas 1961)
and plumbers' thread tape.
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