polyethylene terephthalate (PET)
Polyethylene terephthalate (PET) is a synthetic thermoplastic from the polyester family that is used in many technical areas.
Inelectronics and computer technology, polyester is used as insulation for cables, as a dielectric in film and power capacitors, in magnetic tapes, printed circuit boards, as a protective layer for glass fibers and in membrane keyboards.
As a dielectric, polyester has a permittivity of 3.3 at 1 kHz, the dielectric strength is 580 V/µm, the on-resistance is `10^18` and the permissible operating temperature is between -50 °C and 100 °C. Film capacitors with metal foil and dielectric film have the marking"KT".
Another application of polyethylene terephthalate is as filament in 3D printers.