Fruit and meat pie microwave container and method

• US 4,626,641 A
• Filed: 12/04/1984
• Issued: 12/02/1986
• Est. Priority Date: 12/04/1984
• Status: Expired due to Term

• Current Assignee: Graphic Packaging International Incorporated
• Original Assignee: James River Corporation (KOCH Industries Incorporated)
• Inventors: Brown, Richard K.
• Primary Examiner(s): Leung, Philip H.
• Application Number:
  US06/678,216
• Time in Patent Office: 728 Days
• Field of Search: 219/10.55 E, 219/10.55 M, 219/10.55 F, 219/10.55 R, 219/387, 426/107, 426/113, 426/241, 426/243, 426/114, 426/124, 99/DIG. 14, 99/451
• US Class Current: 219/729
• CPC Class Codes: B65D 2581/3472 Aluminium or compounds thereof
• CPC Class Codes: B65D 2581/3489 Microwave reflector, i.e. microwave shield B65D2581/3487 takes precedence
• CPC Class Codes: B65D 2581/3494 Microwave susceptor B65D2581/3487 takes precedence
• CPC Class Codes: B65D 81/3453 Rigid containers, e.g. trays, bottles, boxes, cups
• CPC Class Codes: Y10S 99/14 Induction heating

Abstract

A container (2) including a paperboard carton (4) for uniformly heating and crisping the top crust of a large food product such as a pot pie having no side and bottom crusts in a microwave oven including a top panel (9) having crisping means (10) separated by a vertical distance of less than 2.7 centimeters from the top surface of the food product. The crisping means (10) consists of a microwave interactive layer for converting microwave energy received on the inner and outer surfaces of the layer into radiant heat for browning and crisping the top surface of the food product. Crisping means (10) also reflects heat radiated by the top surface of the food product back onto that surface for additional browning and crisping. Uniformity of heating is provided by partially shielding the food product during its exposure to microwave energy, thereby also preventing overheating, loss of mass and changes in texture.

Claims

1. A container for protection of a food product during shipment and for use in heating, crisping and browning the food product having a top surface in a microwave oven, comprising:

(a) an insert means for containing the food product, said insert means having a predetermined height; and

(b) a microwave transmissive outer carton means for containing and supporting said insert means, said outer carton means having a cooking means for browning and crisping the top surface of the food product through radiated heat energy that includes a layer of microwave interactive material affixed to an underside of a top wall of said outer carton, and said outer carton means defining a receiving space for the insert means of a second predetermined height that is greater than the height of said insert means, in a manner coordinated to the food product intended for use therein, for causing said layer of microwave interactive material to be vertically spaced above the top surface of the food product by a vertical distance which maximizes the browning and crisping effect of said cooking means without overcooking or scorching the top surface of the food product, said vertical distance being no greater than approximately 2.7 cm.

2. A container as defined in claim 1, wherein said insert means is formed, at least in part, from a paperboard blank including a layer of aluminum foil which has been laminated to one surface thereof for shielding the contents thereof from direct exposure to microwave energy.

3. A container as defined in claim 1, wherein said insert means is comprised of a paperboard blank laminated with a microwave interactive layer for absorbing microwave energy and converting a portion of that energy into heat, having been pressed into said insert.

4. A container as defined in claim 1, wherein said insert means includes

(a) microwave transparent tray means for containing said food product and for maintaining the top surface at a uniform distance away from said cooking means, and

(b) shielding means associated with said microwave transparent tray means for independently controlling the amount of microwave energy reaching said microwave transparent tray means.

5. A container as defined in claim 4, wherein said microwave transparent tray means is thermoformed plastic.

6. A container as defined in claim 4, wherein said shielding means is formed of paperboard and aluminum foil laminated to one surface of said paperboard.

7. A container as defined in claim 4, wherein said shielding means is formed from a unitary inner blank having plural panels hingedly interconnected along foldlines and a layer of aluminum laminated to one surface of said unitary inner blank.

8. A container as defined in claim 7, wherein said panels of said unitary inner blank include:

(a) a central panel, said layer of aluminum covering only a portion of one surface of said central panel;

(b) a pair of side panels hingedly connected to said central panel;

(c) a pair of end panels hingedly connected to said central panel; and

(d) two pairs of corner flaps, each pair of which is separately hingedly connected to opposite side edges of one of said end panels.

9. A container as defined in claim 8, wherein each said corner flap is hingedly connected by a pair of slightly divergent foldlines to cause a beveled corner to be formed upon erection of said inner blank and wherein a cut out opening is formed at each of the four corners of said central panel to form corner openings adjacent the bottom corners of said shielding means.

10. A container as defined in claim 8, wherein said portion of said central panel covered by said layer of aluminum is less than approximately 60% of the total area of said central panel.

11. A container as defined in claim 7 for a food product having a filling and a top crust, wherein said vertical distance the microwave interactive layer is vertically spaced from the food product is determined by the thickness of the top crust and by the amount the crust is expected to rise during exposure to microwave energy.

12. A container as defined in claim 11, where said microwave interactive layer is vertically spaced a maximum of 2.7 centimeters away from the top crust of the food product.

13. A container as defined in claim 1, wherein said outer carton means is formed from a unitary outer blank having plural panels hingedly interconnected along fold lines.

14. A container as defined in claim 13, wherein said unitary outer blank is formed of paperboard and said interactive layer is laminated to the inside surface of one of said panels.

15. A container as defined in claim 13, wherein said panels of said unitary outer blank include:

(a) a top panel;

(b) a pair of outer end panels hingedly connected to said top panel;

(c) first and second outer side panels hingedly connected to said top panel;

(d) bottom panel hingedly connected to said second outer side panel;

(e) a pair of inner end panels hingedly connected to said bottom panel; and

(f) an inner side panel hingedly connected to said bottom panel.

16. A method for microwave heating, crisping and browning of food having a doughy crust on the top surface thereof comprising the steps of:

(a) forming a package for containing the food having a microwave interactive layer capable of converting microwave energy into heat connected to the underside of a top wall of the package and positioning food therein in a manner that the interactive layer is spaced a vertical distance above the top surface of the food, said distance being based on a determination of the thickness of the dough crust constituting the top surface of the food and the amount the doughy crust can be expected to be displaced during cooking;

(b) inserting said package into a microwave oven so that the top surface is oriented towards the source of microwave energy;

(c) exposing said package to microwaves;

(d) removing the food from said package; and

(e) further exposing the food to microwaves to complete cooking of the food and the doughy crust.

17. A packaged food product for shipment and heating, crisping and browning in a microwave oven produced by the steps of:

(a) forming a package for containing the food having a microwave interactive layer capable of converting microwave energy into heat connected to the underside of a top wall of the package and positioning food therein in a manner that the interactive layer is spaced a vertical distance above the top surface of the food, said distance being based on a determination of the thickness of the dough crust constituting the top surface of the food and the amount the doughy crust can be expected to be displaced during cooking; and

(b) sealing the package.

18. Packaged food product for shipment and heating, crisping and browning in a microwave oven, comprising:

(a) an insert means containing a food product with a top surface of the food product being disposed at predetermined height relative to a bottom surface of the insert means; and

(b) a microwave transmissive outer carton means, said outer carton means having cooking means for browning and crisping the top surface of the food product through radiated heat energy that includes a layer of microwave interactive material affixed to an underside of a top wall of said outer carton, said outer carton means having an inner receiving space of a second predetermined height that is greater than said predetermined height of the top surface of the food product, said insert means containing said foot product being disposed in said inner receiving space with said layer of microwave interactive material being vertically spaced above said top surface of the food product by a vertical distance which maximizes the browning and crisping effect of said cooking means without overcooking or scorching the top surface of the food product, said vertical distance being no greater than approximately 2.7 cm.

19. Packaged food product for shipment and heating, crisping and browning in a microwave oven, comprising a food product, a microwave transmissive outer carton means having a cooking means for browning and crisping a surface of the food product through radiated heat energy that includes a layer of microwave interactive material affixed to an inner wall surface thereof, and support means supporting said food product within said outer carton means with a surface of the food product being disposed in an exposed facing relationship with respect to said microwave interactive layer wherein said surface is spaced from the microwave interactive layer by a distance which maximizes the browning and crisping effect of said cooking means without overcooking or scorching said surface of the food product, said distance being no greater than approximately 2.7 cm.