Apertured microwave reactive package

Claim 1

A microwave food package assembly for achieving a desired balance of external surface and internal heating of food in a microwave oven, comprising (a) a food item having a density and external dimensions which would normally result in the surface of said food item becoming excessively heated before the interior of said food item is adequately and uniformly heated when subjected to unshielded microwave energy; (b) a sleeve having bottom, top, and opposed side walls and open ends, said sleeve being shaped to be placed in surrounding heat conducting relationship with respect to the top, bottom and sides of said food item such that the ends of said food items are exposed to direct impingement by microwave energy when said food item is heated in a microwave oven, said sleeve being formed of microwave transparent material; (c) a microwave interactive means for absorbing a portion of the microwave energy within the oven and converting the absorbed microwave energy into heat to raise the temperature of said microwave interactive means, said interactive means including a continuous layer of microwave interactive material which permits a limited portion of the microwave energy to be transmitted from outside the package assembly through said microwave interactive means into said food item, said microwave interactive material being coextensive with the entire inner surface of said sleeve and being positioned, because of the shape of said sleeve, adjacent the top, bottom and sides of said food item to cause the top, bottom and sides of said food item to be heated by said microwave interactive material, the degree of interactivity of said microwave interactive material being sufficiently great that the sum of the microwave energy reaching said food item by being transmitted through said microwave interactive material and through the open ends of said sleeve is inadequate to cause the interior of said food item to be adequately heated when the surface of said food item reaches the maximum level of desired surface heating; and (d) microwave apportioning means for creating a desired division between the microwave absorptivity of said microwave interactive material and the microwave absorptivity of said food item, said microwave apportioning means including a portion of said microwave interactive layer surrounding at least a pair of localized non-interactive microwave permeable areas through which microwave energy may pass into the interior of said food item, said areas being surrounded by uninterrupted edges of said continuous microwave interactive material with all diametrically opposed sections of said edge being sufficiently separated to preclude microwave interactivity between said diametrically opposed sections, said microwave apportioning means including at least a pair of apertures formed in the portions of said microwave interactive material which are co-extensive with said opposed side walls.