Polyester in 1929: Carothers esters · 595

Polyester ((C10H8O4)n PET) is a family of grades whose density ~1.38 g/cm³, heat band ~250–260 °C, and fire letter melts and drips unless FR. Polyester is sold as grades, not as a single substance. Chemistry (C10H8O4)n PET, density ~1.38 g/cm³, heat band ~250–260 °C. This atlas treats Polyester as a system: mill route, coatings, tests and the cavity it sits in.

Conductivity note: low solid; fabrics trap air. Insulation score 50/100 is relative to 32 entries — metals lose, VIPs and aerogels win. Fire letter in editorial use: melts and drips unless FR. Do not equate A1 with “safe in a blaze” or E with “illegal”. Assemblies decide. Origin: Whinfield & Dickson 1941 / DuPont Dacron, United Kingdom / US. The process chapter follows feedstock → conversion → forming → finish → install.

Uses span buildings to defence / safety. Pairings matter: nylon. Circularity mark 34/100. Ask which scrap, which certificate, which year. Related atlas entries, a short glossary, and three threads that keep Polyester honest. The polyamide rival: tougher wet, different dye class. The blend that made drip-dry shirts.