Abstract: The heating effect of a microwave susceptor can be improved by providing a pattern of microwave transparent areas in the susceptor. The transparent areas are preferably circles having a diameter of about 0.5 inch. The distance between adjacent circles is preferably about 0.5 inch. The susceptor may be used to brown and crispen the crust of frozen pizza heated in a microwave oven. The crust of the pizza is browner, especially at its central area, than the crust of pizza heated using a conventional susceptor.

Abstract: The heating effect of a microwave susceptor can be improved by providing a pattern of microwave transparent areas in the susceptor. The transparent areas are preferably circles having a diameter of about 0.5 inch. The distance between adjacent circles is preferably about 0.5 inch. The susceptor may be used to brown and crispen the crust of frozen pizza heated in a microwave oven. The crust of the pizza is browner, especially at its central area, than the crust of pizza heated using a conventional susceptor.

Abstract: A partially-shielded paperboard tray for heating food in a microwave oven is made from a unitary blank having two sections hingedly joined at a common edge. One section, which forms the bottom stratum of the tray, has a layer of aluminum foil for shielding food along the peripheral wall of the tray from microwave radiation, but the section also has a large aperture to allow the radiation to heat the center of food placed over the aperture. The other section of the blank, which forms the top stratum of the tray, is transparent to microwave radiation and provides an imperforate food-contact surface for retaining food in the tray.

Abstract: A paperboard container for heating products placed therein by microwave energy having a first compartment substantially shielded from microwave energy and a second compartment permeable by microwave energy. The first and second compartments each include a top panel and a bottom surface, where a single bottom panel serves as the bottom surface for both of the first and second compartments. The container further includes a plurality of side panels extending upwardly from the bottom panel and a plurality of side panels extending downwardly from the top panels. Both of the first and second compartments are formed from a unitary, single sheet of microwave permeable paperboard material, wherein the first compartment includes a layer of microwave shielding material laminated to the portion of the sheet of microwave permeable paperboard material which forms a majority of the enclosing surfaces of the first microwave shielded compartment.

Abstract: A microwave responsive heating device useful in microwave packaging for capturing microwave energy in a microwave oven and transmitting the energy to a surface of a food item in a concentrated form to grill, crisp, or brown the surface thereof. The heating device includes an antenna for collecting the microwave energy and a transmission device for transferring the collected energy from the antenna to a surface of a food item. Preferably, the heating device forms an integral portion of the interior of a food package to allow a food item to be stored and cooked therein. The antenna and the transmission device are made from electrically conductive materials and are shaped to, not only, capture and transmit microwave energy efficiently, but also to enhance the intensity of the microwave energy in a concentrated form.

Abstract: Microwave interactive coating compositions are disclosed which comprise finely divided carbon, a powdered inert solid and a binder. A preferred composition comprises finely divided carbon, finely divided microwave reactive metal, powdered inert material and a dielectric binder, preferably an acrylic latex. These compositions are capable of producing microwave reactive heaters comparable to those produced by vapor deposition of metals on a carrier film.

Abstract: A microwave interactive coating composition and microwave reactive paper and paperboard heaters comprising the coating composition are disclosed. The coating compositions which comprise finely divided carbon, a finely divided microwave reactive metallic component, a powdered inert solid and a binder are capable of producing microwave reactive heaters comparable to those produced by vapor deposition of metals on a carrier film.

Abstract: Microwave responsive heaters and packages for food products and the like containing the heaters are disclosed in which the heaters consist of a microwave reactive coating composition on a heat stable substrate which is pattern bonded to a surface to be heated by microwave radiation.