Metallized microwave diffuser films

Claim 2

A microwave diffuser film for use during microwave heating of objects, comprising: (a) a first substrate that is substantially transparent to microwave energy, the substrate having a first surface for receiving a microwave energy field and at least one second surface across which microwave energy is transferred; and (b) microwave-interactive elements deposited on the first surface for interacting with microwave energy received thereon to produce a modified microwave energy field and to transfer said microwave energy field across said at least one second surface, said microwave-interactive elements comprising a plurality of discrete metallic elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a pattern so that the transferred microwave energy field is substantially uniform, the metallic elements separated by nonmetallic areas, said metallic elements substantially incapable of converting microwave energy to heat.

Claim 3

The microwave diffuser film of claim 1, wherein the metallic elements are vapor-deposited.

Claim 4

The microwave diffuser film of claim 2, wherein the metallic elements include metallic material selected from the group consisting of a single metal, a metal alloy, a metal oxide, a mixture of metal oxides, a dispersion of metals, and combinations of the foregoing metallic material.

Claim 5

The microwave diffuser film of claim 3, wherein the metallic material is selected from the group consisting of aluminum, iron, tin, tungsten, nickel, stainless steel, titanium, magnesium, copper, and chromium.

Claim 6

The microwave diffuser film of claim 1, wherein the first substrate is an electrical insulator comprising a polymeric material selected from the group consisting of polyolefins, polyesters, polyamides, polyimides, polysulfones, polyethers, ketones, cellophanes and combinations of the foregoing polymeric materials.

Claim 7

The microwave diffuser film of claim 1, further comprising a second substrate in contact with the microwave-interactive elements, the second substrate substantially transparent to microwave energy.

Claim 8

The microwave diffuser film of claim 6, wherein the second substrate is an electrical insulator comprising a polymeric material selected from the group consisting of polyolefins, polyesters, polyamides, polyimides, polysulfones, polyethers, ketones, cellophanes and combinations of the foregoing polymeric materials.

Claim 9

The microwave diffuser film of claim 1, wherein said metallic elements have an area ranging from about 1 mm 2 to about 625 mm 2 .

Claim 10

A microwave diffuser film for use during microwave heating of objects, comprising: (a) a first substrate that is substantially transparent to microwave energy, the substrate having a first surface for receiving a microwave energy field and at least one second surface across which microwave energy is transferred; and (b) microwave-interactive elements deposited on the first surface for interacting with microwave energy received thereon to produce a modified microwave energy field and to transfer said microwave energy field across said at least one second surface, said microwave-interactive elements comprising a plurality of discrete metallic elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a pattern so that the transferred microwave energy field is substantially uniform, the metallic elements separated by nonmetallic areas, said metallic elements substantially incapable of converting microwave energy to heat, wherein the metallic elements are arranged in a pinwheel pattern.

Claim 11

A microwave diffuser film for use during microwave heating of objects, comprising: (a) a first substrate that is substantially transparent to microwave energy, the substrate having a first surface for receiving a microwave energy field and at least one second surface across which microwave energy is transferred; and (b) microwave-interactive elements deposited on the first surface for interacting with microwave energy received thereon to produce a modified microwave energy field and to transfer said microwave energy field across said at least one second surface, said microwave-interactive elements comprising a plurality of discrete metallic elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a pattern so that the transferred microwave energy field is substantially uniform, the metallic elements separated by nonmetallic areas, said metallic elements substantially incapable of converting microwave energy to heat, wherein the metallic elements are arranged in a pinwheel pattern.

Claim 12

A microwave diffuser film for use in food packaging, comprising: (a) a flexible substrate having opposed first and second surfaces, said substrate being substantially transparent to microwave energy from a microwave energy source; (b) a plurality of first microwave-interactive elements deposited on the first surface of the substrate for spatially distributing microwave energy produced by the microwave energy source and received upon said first microwave-interactive elements, the first microwave-interactive elements arranged in a discontinuous pattern, said elements separated by first continuous, nonmicrowave-interactive areas; (c) a plurality of second microwave-interactive elements deposited on the second surface of the substrate for spatially distributing microwave energy received upon said elements, the second microwave-interactive elements arranged in a discontinuous pattern, said second microwave-interactive elements separated by second continuous, nonmicrowave-interactive areas, the first and second microwave-interactive elements of both surfaces substantially incapable of converting microwave energy into heat.

Claim 13

A microwave diffuser film for use in food packaging, comprising: (a) a flexible substrate having opposed first and second surfaces, said substrate being substantially transparent to microwave energy from a microwave energy source; (b) a plurality of first microwave-interactive elements deposited on the first surface of the substrate for spatially distributing microwave energy produced by the microwave energy source and received upon said first microwave-interactive elements, the first microwave-interactive elements arranged in a discontinuous pattern, said elements separated by first continuous, nonmicrowave-interactive areas; (c) a plurality of second microwave-interactive elements deposited on the second surface of the substrate for spatially distributing microwave energy received upon said elements, the second microwave-interactive elements arranged in a discontinuous pattern, said second microwave-interactive elements separated by second continuous, nonmicrowave-interactive areas, the first and second microwave-interactive elements of both surfaces substantially incapable of converting microwave energy into heat.

Claim 14

The microwave diffuser film of claim 10, wherein the first and second microwave-interactive elements include metal-containing material selected from the group consisting of a single metal, a metal alloy, a metal oxide, a mixture of metal oxides, a dispersion of metals, and combinations of the foregoing metal-containing material.

Claim 15

The microwave diffuser film of claim 11, wherein the microwave-interactive elements are vapor-deposited.

Claim 16

The microwave diffuser of claim 12, wherein the first microwave-interactive elements comprises a plurality of quadrilateral microwave reflective elements in a pattern, said pattern covering at least about 85% to about 95% of the surface area of the first surface of the substrate.

Claim 17

The microwave diffuser of claim 11, wherein the first and second microwave-interactive elements have a resistivity between about 0.05 and about 2.0 ohms per square.

Claim 18

The microwave diffuser of claim 10, wherein the plurality of second microwave-interactive elements deposited on the second surface of the substrate are in phased array relative to the first microwave-interactive elements deposited on the first surface of the substrate.

Claim 19

The microwave diffuser of claim 10, wherein the substrate is an electrical insulator comprising a polymer material selected from the group consisting of polyolefins, polyesters, polyamides, polyimides, polysulfones, polyethers, ketones, cellophanes, and combinations of the foregoing polymeric material.

Claim 20

The microwave diffuser film of claim 10, wherein said first and second microwave-interactive elements have an area ranging from about 1 mm 2 to about 625 mm 2 and said first and second nonmicrowave-interactive areas range from about 0.2 mm to about 2.0 mm.

Claim 21

A food package for microwave cooking of food contained therein, having a susceptor for converting microwave energy into heat; a diffuser for achieving uniformity of heating; wherein said susceptor and said diffuser are copackaged so that microwave energy passes through both and that the heat produced by the susceptor is capable of reaching the food; wherein the diffuser includes a substrate having a first surface for receiving microwave energy from a microwave source and a second surface across which microwave energy is transferred, the substrate having deposited on the first surface a plurality of microwave-interactive elements for spatially distributing microwave energy received thereon, said microwave-interactive elements substantially incapable of converting microwave energy into heat, said microwave-interactive elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a discontinuous pattern so that the transferred microwave energy field is substantially uniform, the microwave-interactive elements separated from each other by a continuous gap lacking said microwave-interactive elements.

Claim 22

A food package for microwave cooking of food contained therein, having a susceptor for converting microwave energy into heat; a diffuser for achieving uniformity of heating; wherein said susceptor and said diffuser are copackaged so that microwave energy passes through both and that the heat produced by the susceptor is capable of reaching the food; wherein the diffuser includes a substrate having a first surface for receiving microwave energy from a microwave source and a second surface across which microwave energy is transferred, the substrate having deposited on the first surface a plurality of microwave-interactive elements for spatially distributing microwave energy received thereon, said microwave-interactive elements substantially incapable of converting microwave energy into heat, said microwave-interactive elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a discontinuous pattern so that the transferred microwave energy field is substantially uniform, the microwave-interactive elements separated from each other by a continuous gap lacking said microwave-interactive elements.

Claim 23

The food package of claim 18, wherein the substrate of the diffuser is an electrical insulator comprising a polymeric material selected from the group consisting of polyolefins, polyesters, polyamides, polyimides, polysulfones, polyethers, ketones, cellophanes, and combinations of the foregoing polymeric material.

Claim 24

The food package of claim 18, wherein the microwave-interactive elements include metal-containing material selected from the group consisting of a single metal, a metal alloy, a metal oxide, a mixture of metal oxides, a dispersion of metals, and combinations of the foregoing metal-containing material.

Claim 25

The food package of claim 19, wherein the discontinuous pattern of microwave-interactive elements comprises a plurality of quadrilateral microwave-reflective elements covering at least about 85% to about 90% of the surface area of the first surface of the substrate.

Claim 26

The food package of claim 21, wherein the reflecting elements are vapor-deposited.

Claim 27

The food package of claim 18, wherein the continuous gap lacking said microwave-interactive elements includes at least one substantially rectangular-shaped gap.

Claim 28

The food package of claim 18, further comprising a second plurality of microwave-interactive elements for spatially distributing microwave energy, said second plurality of microwave-interactive elements deposited on the second surface of the substrate in a discontinuous pattern, the second plurality of microwave-interactive elements separated from each other by a continuous gap lacking said microwave-interactive elements, said second plurality of microwave-interactive elements substantially incapable of converting microwave energy into heat.

Claim 29

The food package of claim 24, wherein the plurality of elements deposited on said first and second substrate surfaces are in phased array relative to each other.

Claim 30

A microwave diffuser film for use in food packaging, comprising: (a) a flexible substrate having opposed first and second surfaces, said substrate being substantially transparent to microwave energy from a microwave energy source; (b) a plurality of first microwave-interactive elements deposited on the first surface of the substrate for spatially distributing microwave energy produced by the microwave energy source and received upon said first microwave-interactive elements, the first microwave-interactive elements arranged in a discontinuous pattern, said elements separated by first continuous, nonmicrowave-interactive areas; (c) a plurality of second microwave-interactive elements deposited on the second surface of the substrate for spatially distributing microwave energy received upon said elements, the second microwave-interactive elements arranged in a discontinuous pattern, said second microwave-interactive elements separated by second continuous, nonmicrowave-interactive areas, the first and second microwave-interactive elements of both surfaces substantially incapable of converting microwave energy into heat, wherein the first and second plurality of microwave-interactive elements are in a pinwheel configuration on a surface of the substrate, the surface selected from the group consisting of the first surface, the second surface and both first and second surfaces.

Claim 31

A microwave diffuser film for use in food packaging, comprising: (a) a flexible substrate having opposed first and second surfaces, said substrate being substantially transparent to microwave energy from a microwave energy source; (b) a plurality of first microwave-interactive elements deposited on the first surface of the substrate for spatially distributing microwave energy produced by the microwave energy source and received upon said first microwave-interactive elements, the first microwave-interactive elements arranged in a discontinuous pattern, said elements separated by first continuous, nonmicrowave-interactive areas; (c) a plurality of second microwave-interactive elements deposited on the second surface of the substrate for spatially distributing microwave energy received upon said elements, the second microwave-interactive elements arranged in a discontinuous pattern, said second microwave-interactive elements separated by second continuous, nonmicrowave-interactive areas, the first and second microwave-interactive elements of both surfaces substantially incapable of converting microwave energy into heat, wherein the first and second plurality of microwave-interactive elements are in a pinwheel configuration on a surface of the substrate, the surface selected from the group consisting of the first surface, the second surface and both first and second surfaces.

Claim 32

A food package for microwave cooking of food contained therein, having a susceptor for converting microwave energy into heat; a diffuser for achieving uniformity of heating; wherein said susceptor and said diffuser are copackaged so that microwave energy passes through both and that the heat produced by the susceptor is capable of reaching the food; the diffuser including a substrate having a first surface for receiving microwave energy from a microwave source and a second surface across which microwave energy is transferred, the substrate having deposited on the first surface a plurality of microwave-interactive elements for spatially distributing microwave energy received thereon, said microwave-interactive elements substantially incapable of converting microwave energy into heat, said microwave-interactive elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a discontinuous pattern so that the transferred microwave energy field is substantially uniform, the elements separated from each other by a continuous gap lacking said microwave-interactive elements, wherein the plurality of microwave-interactive elements are arranged in a pinwheel pattern.

Claim 33

A food package for microwave cooking of food contained therein, having a susceptor for converting microwave energy into heat; a diffuser for achieving uniformity of heating; wherein said susceptor and said diffuser are copackaged so that microwave energy passes through both and that the heat produced by the susceptor is capable of reaching the food; the diffuser including a substrate having a first surface for receiving microwave energy from a microwave source and a second surface across which microwave energy is transferred, the substrate having deposited on the first surface a plurality of microwave-interactive elements for spatially distributing microwave energy received thereon, said microwave-interactive elements substantially incapable of converting microwave energy into heat, said microwave-interactive elements having a sheet resistance in the range of 2.0 to 0.05 ohms per square arranged in a discontinuous pattern so that the transferred microwave energy field is substantially uniform, the elements separated from each other by a continuous gap lacking said microwave-interactive elements, wherein the plurality of microwave-interactive elements are arranged in a pinwheel pattern.