Electric heating cartridge for hair curler - comprises an insulating sleeve and a (semi)conductive heater, e.g. filled rubber or silicone

摘要

An electrical heating cartridge, esp. for hair waving rods or hair curlers, comprises a sleeve of insulating material, e.g., a ceramic or glass, and a heating element inside it, made of an electrically conductive plastics whose resistance has a positive temp. coefficient. The heating element may be a plastics moulding fitting the sleeve. The heating cartridge has a predetermined, desired, even temp. value over its entire surface. This value may be easily and reliably maintained.