Abstract: A microwave moderator for partially attenuating and/or modifying microwave energy to achieve, for instance, more uniform cooking of comestible articles in microwave ovens. Packages, bags, and wraps are disclosed which comprise such microwave moderators and which enable microwave cooking of frozen foods at relatively high microwave oven power levels without requiring precooking, defrosting or oven power level changes. Such a moderator may comprise an array of alternately disposed or spaced areas of microwave reflective material, and complemental-shape, substantially microwave transparent zones. One species of such moderators is exemplified by a wrap which comprises a perforate sheet of microwave reflective material; for instance, aluminum foil.

Abstract: A dimensionally stable, temperature responsive microwave energy moderator. The moderator may comprise a sheet-like laminate having at least one lamina of microwave energy reflective material with at one aperture formed therein of such dimensions as to enable passage therethrough of a substantial portion of impinging microwave energy of a predetermined nominal frequency. At least one aperture-bridging microwave energy reflective member is provided together with means responsive to a predetermined temperature range to shift the aperture-bridging member from an inactive position to a position bridging the aperture, whereby to reduce the transmission of the microwave energy through the aperture. The moderator also has outer laminae of electrically insulative, microwave energy transmitting material with the microwave energy reflective lamina, the aperture-bridging means and the temperature responsive means located therebetween.

Abstract: A vessel, reflective to microwave electromagnetic energy, having at least one aperture to permit passage of said microwave energy to its contents and a shielding device, responsive to a preselected internal temperature of the vessel contents, to close said at least one aperture to prevent further passage of said microwave energy to the vessel contents.