Self-regulating heating article having electrodes directly connected to a PTC layer.

摘要

A self-regulating heating article (10) comprises a first elongate layer (11) formed by a crystalline polymeric composition of high crystallinity and conductive particles dispersed in the polymeric composition to exhibit a positive temperature coefficient of resistance. A pair of elongate electrodes (12, 131, which are adapted for connection to a mains supply, are secured one on each surface of the first layer to develop a potential in the direction of thickness of the first layer. The electrodes are arranged so that a creeping distance which is greater than the thickness of the first layer is established between the electrodes along peripheral edges thereof. The creeping distance prevents insulation breakdown and ensures safe, high wattage operation at mains voltages.