Abstract: In the fabrication of a resistance heater for a carton for packaging a pizza, an aluminum metallized sheet is adhered to a paperboard panel, a generally U-shaped strip of arc-sprayed zinc is applied to three edge portions of the upwardly facing electrically conductive metal layer of the metallized sheet, the interconnecting portion of the U-shaped strip and the immediately underlying metal layer are severed, and the metal layer is severed along a line extending adjacent the same interconnecting portion to the side thereof enclosed by the U-shaped strip, so that each of the severed sections of the interconnecting portion serves as a terminal for a corresponding leg portion of the U-shaped strip comprising the electrodes for the intermediate region of the metallized sheet.

Abstract: A paperboard carton for packaging a pizza is provided with a substantially rigid, pizza-supporting electrical-resistance heater insert comprising a corrugated paperboard panel having laminated thereto a sheet of vacuum-metallized glassine. Arc-sprayed zinc bus bars extend over opposed edges of the metallized sheet and serve as electrodes for conducting electricity through the sheet as the resistor element. Electrical energy is supplied to the electrodes by a removable terminal clip that extends through an opening provided in a side wall of the carton and both electrically and mechanically engages suitably presented electrode terminals. An insulating sheet of coated paper extends over the metallized surface, the electrodes, and the bus bars, and serves as the immediate support surface for the pizza.