PTFE in 1938: Plunkett cylinder
The behaviour of PTFE is written as 1938’s “Plunkett cylinder,” fixed by 327. An advert’s adjective is not a melting point. “Room temperature” alone is not a figure. Scores compare PTFE with the rest of the atlas on strength, heat, fire behaviour, insulation, workability and circularity. They are editorial, not certificates.
PTFE is sold as grades, not as a single substance. Chemistry (C2F4)n, density ~2.2 g/cm³, heat band ~327 °C. This atlas treats PTFE as a system: mill route, coatings, tests and the cavity it sits in. Conductivity note: ~0.25 W/m·K. Insulation score 32/100 is relative to 32 entries — metals lose, VIPs and aerogels win.
Fire letter in editorial use: high OI but pyrolysis fumes. Do not equate A1 with “safe in a blaze” or E with “illegal”. Assemblies decide. Origin: DuPont 1938 Plunkett, United States. The process chapter follows feedstock → conversion → forming → finish → install. Uses span buildings to defence / safety. Pairings matter: silicone.
Circularity mark 24/100. Ask which scrap, which certificate, which year. Related atlas entries, a short glossary, and three threads that keep PTFE honest. The other high-temp elastomer/plastic in kitchens. The cheap olefin PTFE replaced in hostile chemistry. Lined steel vs glass-lined — different plants choose differently.
“Plunkett cylinder” for PTFE in 1938 carries 327. Praise without that figure is not a property.1938
Figures to keep
- Year of the condition
- 1938
- Property figure
- 327
- Material
- PTFE
- Use line
- Plunkett cylinder
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