Abstract: An microwave container with synergistic active elements provides more uniform heating than prior art containers, and is more tolerant of variations in food product, load and heating conditions. The active elements (which are conductive and microwave opaque) include an annular ring in the base of the container, a band extending from the base of the side walls up the walls to a level approximately even with the anticipated fill level in the container, a lip extending from the bottom of the side walls onto the base, and at least one, preferably three cooperative active elements in the lid of the container. These containers can be used for thawing and cooking frozen, uncooked meats and other foods, with which prior art containers produced unsatisfactory results.

Abstract: The invention provides a peelable laminated structure suitable for use in a peelable seal joining a flexible closure element (23) to a container (20) or in foil/polymer laminates used for packaging and the like. The structure comprises a porous-anodizable metal substrate (11) and a porous anodic film (12) overlying and attached to a surface of the substrate. The porous anodic film (12) has a weakened stratum (19) positioned between an outer film part and an underlying structure including the metal substrate (11). The weakened stratum (19) is strong enough in use of said structure to prevent detachment of the outer film part from the underlying structure, except by deliberate peeling of the flexible closure element (23). The invention also relates to a process for producing the structure and to peelable containers and recyclable laminates incorporating the structure.

Abstract: Susceptors used for browning or crisping food prepared in microwave ovens and processes for the production of such susceptors. The susceptors are produced by laminating an anodizable metal (e.g. aluminum, tantalum, niobium, zirconium, titanium or tungsten) onto a suitable non-metallic substrate (e.g a heat resistant polyester film, a paperboard sheet or a glass, plastic or ceramic article) and anodizing the metal layer to form an anodic film covering a residual metal layer of suitable thinness to generate heat by resistance heating when irradiated by microwaves. The anodic film acts as a barrier to prevent the migration of any degradation products to the foodstuff undergoing the heating procedure. The susceptors can be used as wrappings for food items, as package inserts or as internal coatings on food containers and the like.

Abstract: A microwave tunnel oven receives a series of packages each comprising a container and a load in the container to be heated by microwave energy. The oven has a conveyor with a series of carriers each for receiving one of the packages and conveying it through the oven. The improvement comprises modifying the microwave field in the load during its irradiation in the oven in a manner to generate higher order modes of microwave energy in the load to enhance the uniformity of heating throughout the load. The structure for achieving the field modification is divided into two parts, one part being formed on the conveyor and the other part being formed either on the package or on a subsidiary conveyor that extends parallel to the main conveyor.

Abstract: A container for heating a substance, e.g. food, in a microwave oven has a bottom transparent to microwave energy. The container is supported on a stand that contains one or more electrically conductive plates (or apertures in an electrically conductive sheet) that generate at least one mode of microwave energy of higher order than the fundamental modes. The stand also serves to support the container above the higher order mode generating plates (or apertures) so that the undersurface of the substance is spaced from them by a uniform predetermined distance. The arrangement has the known features of "bottom heating", i.e. taking advantage of the natural heat flow in the substance, while achieving more uniform heating of the substance by virtue of the higher order mode or modes.

Abstract: A product comprises a shallow container and a load located therein for heating by microwave energy. This product is designed either to be used with, or itself to incorporate, a structure for generating or enhancing at least one mode of the microwave energy of an order higher than a fundamental mode that is determined by boundary conditions resulting from the lateral dimensions of either the container of the load or both. The invention resides in controlling the depth of the load in the container in such a manner that, upon irradiation of the product with the microwave energy, the power absorbed by the load from a higher order mode is at or near a maximum value, while preferably the power absorbed by the load from the fundamental mode is at or near a minimum value.

Abstract: A catalyst device comprises a porous catalytically active inorganic membrane, means for presenting a fluid reactant to a first surface of the membrane and means for recovering a fluid reaction product from the second surface of the membrane. The membrane is preferably an anodic aluminum oxide membrane with a deposit of catalytically active material present within the pores, preferably concentrated in the ends of the pores adjacent the second surface of the membrane.