from ptfe if ptfe is used in a bonding layer such that it is in an unfused condition in a tape ready for wrapping on a wire the thickness of such a layer should be about 0 2 0 4 mil in addition the thickness of the adhesives layers if they contain tfe copolymer should be minimized while the details of the fluoropolymer behavior in the presence of an intense high temperature electrical arc are not completely understood improved arc tracking of the claimed composites may well involve the well known ablative behavior of ptfe at elevated temperatures for that reason it may also be beneficial to incorporate additives into the fluoropolymer layers used to create an insulation system which are also ablative in nature such additives include minerals which outgas at the temperature of the arc such as carbonates which evolve carbon dioxide e g calcium or magnesium carbonate or minerals containing water of hydration other suitable additives would include polymers which like ptfe itself decompose without producing carbonaceous or other conductive by products on decomposition these additives may be incorporated into the fluoropolymer layers of the claimed composite preferably in those layers nearest the conductor to be insulated in order to avoid bonding of any fluoropolymer layers of the claimed composite to the conductor itself during tape wrapping it.