Polyester
Polyethylene terephthalate is a synthetic material that, for the wire and cable industry, is used extensively in the production of a high strength moisture resistant film used as a cable core wrap. Polyester film products are characterized by excellent physical properties, good chemical resistance, good electrical properties and a wide range of service temperatures from -60°C to 150°C. See Mylar. Polyester can also be extruded over a conductor to provide a robust, but inflexible insulating jacket.