Heating filament with temperature controlled resistance comprises conductor wire with conducting polymer and spiral wire layers inside electrically insulating and heat conducting covering

摘要

The heating filament is made from a central conductor wire coated with a first layer of a polymer material with PTC effect, covered by a spiral wound or braided conducting wire, and an outer layer of an electrically insulating and heat conducting material, also a polymer. The PTC material has a density of between 0.05 and 3 kg/cu m.