Microwave energy interactive heating sheet

• US 20070251943A1
• Filed: 05/10/2007
• Published: 11/01/2007
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: Graphic Packaging International LLC (Graphic Packaging International Incorporated)
• Original Assignee: Graphic Packaging International Incorporated
• Inventors: Middleton, Scott, Cole, Lorin, Wnek, Patrick, Robison, Richard
• Granted Patent: US 8,158,914 B2
• Time in Patent Office: Days
• US Class Current: 219/730
• CPC Class Codes: B65D 2581/3452 Packages having a plurality of microwave reactive layers, i.e. multiple or overlapping microwave reactive layers
• CPC Class Codes: B65D 2581/3494 Microwave susceptor B65D2581/3487 takes precedence
• CPC Class Codes: B65D 81/3446 specially adapted to be heated by microwaves
• CPC Class Codes: B65D 81/3461 Flexible containers, e.g. bags, pouches, envelopes
• CPC Class Codes: B65D 81/3893 formed with double walls, i.e. hollow

Abstract

A microwave energy interactive heating sheet includes at least two susceptor layers and a plurality of expandable insulating cells. At least some of the expandable insulating cells inflate when exposed to microwave energy.

Claims

1. A microwave energy interactive heating sheet comprising:

at least two susceptor layers; and

a plurality of expandable insulating cells.

2. The microwave energy interactive heating sheet of claim 1, wherein at least some of the expandable insulating cells inflate when the microwave energy interactive heating sheet is exposed to microwave energy.

3. The microwave energy interactive heating sheet of claim 1, wherein

prior to exposure to microwave energy, the microwave energy interactive heating sheet is substantially planar, and

after sufficient exposure to microwave energy, the microwave energy interactive heating sheet has a multi-dimensional, lofted shape.

4. The microwave energy interactive heating sheet of claim 1, wherein

the microwave energy interactive heating sheet includes a first surface intended to be contacted by a food item desired to be browned and/or crisped, and

at least one of the susceptor layers is proximate the first surface.

5. The microwave energy interactive heating sheet of claim 1, wherein

the at least two susceptor layers include a first susceptor layer and a second susceptor layer, and

the microwave energy interactive heating sheet further comprises, in a layered configuration:

a first polymer film layer,

the first susceptor layer,

a first moisture-containing layer,

a patterned adhesive layer,

a second moisture-containing layer,

the second susceptor layer, and

a second polymer film layer,

wherein the patterned adhesive layer defines the plurality of expandable insulating cells between the first moisture-containing layer and the second moisture-containing layer.

6. A microwave energy interactive heating sheet comprising:

a first ply of microwave energy interactive insulating material and a second ply of microwave energy interactive insulating material in a layered configuration,

wherein the first ply of microwave energy interactive insulating material includes

a layer of microwave energy interactive material that converts microwave energy to thermal energy,

a moisture-containing layer at least partially joined to the layer of microwave energy interactive material, and

a polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the polymer film layer.

7. The microwave energy interactive heating sheet of claim 6, wherein the first ply of microwave energy interactive insulating material and the second ply of microwave energy interactive insulating material are at least partially joined.

8. The microwave energy interactive heating sheet of claim 6, wherein the first ply of microwave energy interactive insulating material and the second ply of microwave energy interactive insulating material are at least partially joined along a respective peripheral edge of each the first ply and the second ply to define an interior space for receiving a food item.

9. The microwave energy interactive heating sheet of claim 6, having a surface intended to be in contact with a food item, wherein the layer of microwave energy interactive material that converts microwave energy to thermal energy is proximate the first surface.

10. The microwave energy interactive heating sheet of claim 6, in combination with a dimensionally stable construct, wherein

the dimensionally stable construct includes a first surface and a second surface opposite the first surface,

the first surface is intended to be in contact with a food item, and

the second surface is intended to be in contact with the microwave energy interactive heating sheet.

11. The microwave energy interactive heating sheet of claim 6, wherein the second ply of microwave energy interactive insulating material includes

a layer of microwave energy interactive material that converts microwave energy to thermal energy,

a moisture-containing layer at least partially joined to the layer of microwave energy interactive material, and

a polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the polymer film layer.

12. A microwave energy interactive heating sheet comprising:

at least two plies of a microwave energy interactive insulating material arranged in a superposed, layered configuration, wherein each ply of microwave energy interactive insulating material includes

a susceptor film comprising a microwave energy interactive material supported on a first polymer film layer,

a moisture-containing layer superposed with the microwave energy interactive material, and

a second polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the second polymer film layer,

wherein at least some of the expandable insulating cells inflate when the microwave energy interactive heating sheet is exposed to microwave energy.

13. The microwave energy interactive heating sheet of claim 12, wherein the plies are at least partially joined to one another.

14. The microwave energy interactive heating sheet of claim 12, wherein

the at least two plies of microwave energy interactive insulating material includes a first ply and a second ply, and

the first ply and the second ply are at least partially joined along respective peripheral edges of the first ply and the second ply to define a cavity for receiving a food item.

15. The microwave energy interactive heating sheet of claim 12, having a surface intended to be in contact with a food item, wherein the susceptor film layer in one of the plies is proximate the first surface.

16. The microwave energy interactive heating sheet of claim 12, in combination with a dimensionally stable construct, wherein

the dimensionally stable construct includes a first surface and a second surface opposite the first surface,

the first surface is intended to be in contact with a food item, and

the second surface is intended to be in contact with the microwave energy interactive heating sheet.

17. The microwave energy interactive heating sheet of claim 12, in combination with a food item and a dimensionally stable construct in a packaging arrangement, wherein

the microwave energy interactive heating sheet overlies the food item, and

the food item overlies the dimensionally stable construct.

18. The microwave energy interactive heating sheet of claim 17, wherein information about the food item is printed on the microwave energy interactive heating sheet.

19. The microwave energy interactive heating sheet of claim 17, wherein the microwave energy interactive heating sheet is in a folded configuration.

20. A package for a microwavable food item, the package comprising:

a pair of separably joined, opposed panels that at least partially define a cavity for receiving a food item, wherein, upon removal of the food item from the cavity, the panels can be reconfigured to collectively form a microwave energy interactive heating sheet including

at least two susceptor layers; and

at least one layer of expandable insulating cells.