US 4,061,898 · Granted 1977-12-06

Heat cap

A heat cap for reducing processing time of permanent waves for the hair includes a cap which fits over the head, and a thermostatically controlled electrical heating element inside the cap for applying a selected heat distribution pattern to thermally-activated permanent wave solutions applied to the hair. The heating element comprises an electrical resistance heating film, preferably a meander pattern of conductive metal foil supported by a flexible, high temperature-resistant, fibrous dielectric sheet, such as aramid paper. The conductor develops a selected heat distribution pattern to be developed within the cap which, in turn, produces a generally uniform rate of heat processing for the permanent wave. The cap opens and closes along a pair of splits in the temple regions of the cap. Fasteners, preferably cooperating sections of Velcro material, are located along opposite sides of each split and are used to releasably close selected overlapping portions of the cap adjacent each split so the cap will closely conform to the size and shape of the head and the permanent wave structure to apply heat uniformly to all rollers in the permanent wave.

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