Microwave energy interactive heating sheet

• US 8,158,914 B2
• Filed: 05/10/2007
• Issued: 04/17/2012
• 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: Wnek, Patrick H., Cole, Lorin R., Middleton, Scott W., Robison, Richard G.
• Primary Examiner(s): VAN, QUANG T
• Application Number:
  US11/801,646
• Publication Number:
  US 20070251943A1
• Time in Patent Office: 1,804 Days
• Field of Search: 219725-735, 219/759, 219/782, 426/107, 426/109, 426/118, 426/234, 426/241, 426/243, 99D/IG.14
• 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 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 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 are configured to inflate when the microwave energy interactive heating sheet is exposed to microwave energy.

2. The microwave energy interactive heating sheet of claim 1, wherein the at least two plies are at least partially joined to one another.

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

4. The microwave energy interactive heating sheet of claim 1, having a surface intended to be in contact with a food item, wherein the susceptor film of one of the plies is proximate the surface of the food item.

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

6. The microwave energy interactive heating sheet of claim 1, 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.

7. The combination of claim 6, wherein information about the food item is printed on the microwave energy interactive heating sheet.

8. The combination of claim 6, wherein the microwave energy interactive heating sheet is in a folded configuration.

9. The microwave energy interactive heating sheet of claim 1, in combination with a food item and a dimensionally stable construct in a packaging arrangement, wherein the microwave energy interactive heating sheet is disposed between the food item and the dimensionally stable construct.

10. The microwave energy interactive heating sheet of claim 1, in combination with a food item and a dimensionally stable construct in a packaging arrangement, wherein the microwave energy interactive heating sheet is at least partially joined to the dimensionally stable construct.

11. The microwave energy interactive heating sheet of claim 1, in combination with a food item, wherein

the food item has a periphery, and

the microwave energy interactive heating sheet has a peripheral margin that extends beyond the periphery of the food item.

12. The combination of claim 11, wherein

the periphery of the food item is desirably browned and/or crisped, and

upon sufficient exposure to microwave energy, the peripheral margin of the heating sheet lofts upwardly around at least a portion of the periphery of the food item.

16. The microwave energy interactive heating sheet of claim 1, 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.

17. The microwave energy interactive heating sheet of claim 16, wherein

in a first configuration, the food item is positioned within the cavity, and

in a second configuration, with the food item removed from the cavity, the first ply and second ply of microwave energy interactive insulating material are in a superposed relationship and the food item is positioned on the superposed first ply and second ply of microwave energy interactive insulating material.

13. A microwave energy interactive heating sheet comprising:

at least two plies of 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 microwave energy interactive material supported on a first polymer film,

a support layer joined to the microwave energy interactive material, the support layer comprising a material selected from the group consisting of paper, paperboard, and polymer film, and

a second polymer film joined to the support layer such that the support layer is positioned between the microwave energy interactive material and the second polymer film, the second polymer film being selectively joined to the support layer to define at least one closed cell between the support layer and the second polymer film layer, wherein the closed cell is operative for inflating in response to sufficient exposure to microwave energy.

14. The microwave energy interactive heating sheet of claim 13, wherein the at least two plies are separate from one another.

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

18. The microwave energy interactive heating sheet of claim 13, 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 for contacting a food item, and

the second surface is for contacting the microwave energy interactive heating sheet.

19. The microwave energy interactive heating sheet of claim 13, 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.

20. The combination of claim 19, wherein information about the food item is printed on the microwave energy interactive heating sheet.

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

22. The microwave energy interactive heating sheet of claim 13, in combination with a food item and a dimensionally stable construct in a packaging arrangement, wherein the microwave energy interactive heating sheet is disposed between the food item and the dimensionally stable construct.

23. The microwave energy interactive heating sheet of claim 13, in combination with a food item and a dimensionally stable construct in a packaging arrangement, wherein the microwave energy interactive heating sheet is at least partially joined to the dimensionally stable construct.

24. The microwave energy interactive heating sheet of claim 13, in combination with a food item, wherein

the food item has a periphery, and

the microwave energy interactive heating sheet has a peripheral margin that extends beyond the periphery of the food item.

25. The combination of claim 24, in combination with the food item, wherein

the periphery of the food item is desirably browned and/or crisped, and

upon sufficient exposure to microwave energy, the peripheral margin of the heating sheet is configured to loft upwardly around at least a portion of the periphery of the food item.