U.S. patent application number 12/580463 was filed with the patent office on 2010-03-04 for package for heating a food product.
Invention is credited to Michael D. Sweet.
Application Number | 20100051675 12/580463 |
Document ID | / |
Family ID | 39944200 |
Filed Date | 2010-03-04 |
United States Patent
Application |
20100051675 |
Kind Code |
A1 |
Sweet; Michael D. |
March 4, 2010 |
PACKAGE FOR HEATING A FOOD PRODUCT
Abstract
A package for holding a food product. The package comprises a
first central panel, an end panel foldably connected to the first
central panel, and a second central panel foldably connected to the
end panel. At least one first side panel is foldably connected to
the first central panel and comprises an opening. At least one
second side panel is foldably connected to the second central
panel. A retention flap is foldably connected to the second side
panel. The retention flap comprises a locking portion shaped to be
received in the opening and retain the first panel in a closed
position of the package.
Inventors: |
Sweet; Michael D.;
(Penacook, NH) |
Correspondence
Address: |
WOMBLE CARLYLE SANDRIDGE & RICE, PLLC
ATTN: PATENT DOCKETING, P.O. BOX 7037
ATLANTA
GA
30357-0037
US
|
Family ID: |
39944200 |
Appl. No.: |
12/580463 |
Filed: |
October 16, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/US2008/062192 |
May 1, 2008 |
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12580463 |
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60915142 |
May 1, 2007 |
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Current U.S.
Class: |
229/115 ;
206/551 |
Current CPC
Class: |
B65D 2581/3477 20130101;
B65D 2581/3472 20130101; B65D 2581/3474 20130101; B65D 81/3453
20130101; B65D 2581/3489 20130101; B65D 2205/02 20130101; B65D
2581/3498 20130101; B65D 5/2028 20130101; B65D 2585/366 20130101;
B65D 2581/3479 20130101; B65D 5/667 20130101 |
Class at
Publication: |
229/115 ;
206/551 |
International
Class: |
B65D 5/00 20060101
B65D005/00; A45C 11/20 20060101 A45C011/20 |
Claims
1. A package for holding a food product, the package comprising: a
first central panel; an end panel foldably connected to the first
central panel; a second central panel foldably connected to the end
panel; at least one first side panel foldably connected to the
first central panel, a least one second side panel foldably
connected to the second central panel, the at least one second side
panel comprising an opening; and a retention flap foldably
connected to the at least one first side panel, the retention flap
comprising a locking portion shaped to be received in the opening
to retain the first central panel in a closed position of the
package.
2. The package of claim 1 wherein the retention flap is foldably
connected to the at least one first side panel at an oblique fold
line.
3. The package of claim 2 wherein the locking portion is formed at
least in part by a notch extending between two portions of the
oblique fold line.
4. The package of claim 3 wherein the notch has an elongate portion
and two transverse end portions, the elongate portion being
generally parallel to the oblique fold line.
5. The package of claim 4 wherein the two portions of the oblique
fold line, the elongate portion, and the transverse end portions at
least partially form a top edge of the at least one first side
panel, and the transverse end portions extend past the oblique fold
line into the retention flap.
6. The package of claim 1 wherein the second side panel is foldably
connected to the first panel at an oblique fold line.
7. The package of claim 6 wherein the opening is elongate and
extends between portions of the oblique fold line.
8. The package of claim 1 wherein the locking portion is positioned
to extend laterally outward from a top edge of the first side
panel.
9. The package of claim 8 wherein the opening is positioned at a
location corresponding with a top edge of the second side
panel.
10. The package of claim 1 further comprising a microwave
interactive element attached to at least one of the first central
panel and the second central panel.
11. A blank for forming a package for holding a food product, the
blank comprising: a first central panel; an end panel foldably
connected to the first central panel; a second central panel
foldably connected to the end panel; a least one first side panel
foldably connected to the first central panel; at least one second
side panel foldably connected to the second central panel; a
retention flap foldably connected to the first side panel; and
retention features comprising a locking portion of the retention
flap and an opening in the second side panel, the locking portion
is shaped to be received in the opening and retain the first
central panel in a closed position of the package formed from the
blank.
12. The blank of claim 11 wherein the retention flap is foldably
connected to the first side panel at an oblique fold line.
13. The blank of claim 12 wherein the locking portion is formed at
least in part by a notch extending between two portions of the
oblique fold line.
14. The blank of claim 13 wherein the notch has an elongate portion
and two transverse end portions, the elongate portion being
generally parallel to the oblique fold line and the transverse end
portions extending past the oblique fold line into the retention
flap.
15. The blank of claim 11 wherein the second side panel is foldably
connected to the second central panel at an oblique fold line, and
the opening is elongate and extends between portions of the oblique
fold line.
16. The blank of claim 11 further comprising a microwave
interactive element attached to at least one of the first central
panel and the second central panel.
17. A method of forming a package from a blank, the method
comprising: obtaining a blank comprising a first central panel, an
end panel foldably attached to the first central panel, a second
central panel foldably attached to the end panel, at least two
first side panels foldably attached to the first central panel, at
least two second side panels foldably attached to the second
central panel, a retention flap foldably attached to at least one
of the first side panels, and retention features comprising a
locking portion of the retention flap and an opening in at least
one of the second side panels; upwardly folding the first side
panels relative to the first central panel to from a first tray;
upwardly folding the second side panels relative to the second
central panel to form a second tray; downwardly folding the
retention flap; folding the second tray over the first tray; and
securing the second tray in a closed position of the package by
actuating the retention features of the blank comprising inserting
the locking portion of the retention flap in the opening.
18. The method of claim 17 wherein the folding the second tray over
the first tray comprises positioning the end panel in an upright
position and placing the second side panels in an overlapping
relationship with the first side panels.
19. The method of claim 17 wherein downwardly folding the retention
flap comprises positioning the retention flap to be generally
parallel to the first central panel so that the locking portion
projects outward from the at least one first side panel.
20. The method of claim 19 wherein the locking portion of the
retention flap is positioned at a location corresponding with a top
edge of the at least one first side panel.
21. The method of claim 20 wherein the opening is positioned at a
location corresponding with a top edge of the at least one second
side panel.
22. The method of claim 17 wherein the first tray and the second
tray are generally triangular.
23. The method of claim 17 further comprising inserting a food
product in the package.
24. The method of claim 23 further comprising heating the package
to warm the food product.
25. A package for holding a food product, the package comprising: a
first tray comprising a first central panel and at least two first
side panels foldably connected to the first panel; a second tray
comprising a second central panel and at least two second side
panels foldably connected to the second central panel; an end panel
foldably connected to the first tray and the second tray; a
retention flap foldably attached to at least one of the first side
panels; and retention features comprising a locking portion of the
retention flap and an opening in one of the second side panels, the
locking portion is shaped to be received in the opening and retain
the second tray in a closed position.
26. The package of claim 25 wherein at least two first side panels
are respectively foldably connected to the first central panel at
oblique fold lines and the at least two second side panels are
respectively foldably connected to the second central panel at
oblique fold lines.
27. The package of claim 25 wherein the locking portion is
positioned at a location corresponding with a top edge in the at
least one of the first side panels and the opening is positioned at
a location corresponding with a top edge of the one of the second
side panels.
28. The package of claim 25 further comprising a microwave
interactive element attached to at least one of the first central
panel and the second central panel.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of prior PCT
Application No. PCT/US2008/062192, filed Nov. 1, 2008, entitled
"Package For Heating A Food Product," which PCT application claims
the benefit of U.S. Provisional Application No. 60/915,142, which
was filed on May 1, 2007.
INCORPORATION BY REFERENCE
[0002] The entire disclosures of both PCT Application No.
PCT/US2008/062192, filed Nov. 1, 2008, and U.S. Provisional
Application No. 60/915,142, filed May 1, 2007, are incorporated
herein by reference as if set forth in their entireties.
BACKGROUND OF THE DISCLOSURE
[0003] The present disclosure generally relates to packages for
holding and/or heating food products.
[0004] Cartons, constructs, or packages, such as paperboard
packages, for holding food products such as frozen pizzas are
known. The packages typically are square-shaped and are closed at
the top, bottom, sides, front, and back to form a six-sided, fully
enclosed package that contains the pizza and provides surface areas
for printing graphics such as advertisements or nutritional
information. It is desired to provide a package that is both
suitable for holding one or more food products prior to preparation
of the food product, and for holding the food product during
heating in an oven, such as a microwave oven. Furthermore, and
depending upon the circumstances, it may be desired to provide a
package that enhances the heating, browning, and/or crisping of the
food products in a microwave oven.
SUMMARY OF SOME ASPECTS OF THE DISCLOSURE
[0005] In one aspect, the disclosure is generally directed to a
package for holding a food product. The package comprises a first
central panel, an end panel foldably connected to the first central
panel, and a second central panel foldably connected to the end
panel. At least one first side panel is foldably connected to the
first central panel and at least one second side panel is foldably
connected to the second central panel. The at least one second side
panel comprises an opening. A retention flap is foldably connected
to the at least one first side panel. The retention flap comprises
a locking portion shaped to be received in the opening to retain
the first central panel in a closed position of the package.
[0006] In another aspect, the disclosure is generally directed to a
blank for forming a package for holding a food product. The blank
comprises a first central panel, an end panel foldably connected to
the first central panel, and a second central panel foldably
connected to the end panel. At least one first side panel is
foldably connected to the first central panel, and at least one
second side panel is foldably connected to the second central
panel. A retention flap is foldably connected to the first side
panel. Retention features comprise a locking portion of the
retention flap and an opening in the at least one second side
panel. The locking portion is shaped to be received in the opening
and retain the first central panel in a closed position of the
package formed from the blank.
[0007] In another aspect, the disclosure is generally directed to a
method of forming a package from a blank. The method comprises
providing a blank comprising a first central panel, an end panel
foldably attached to the first central panel, and a second central
panel foldably attached to the end panel. The blank has at least
two first side panels foldably attached to the first central panel,
and at least two second side panels foldably attached to the second
central panel. A retention flap is foldably attached to at least
one of the first side panels. The blank has retention features
comprising a locking portion of the retention flap and an opening
in at least one of the second side panels. The method further
comprising upwardly folding the first side panels relative to the
first central panel to from a first tray, upwardly folding the
second side panels relative to the second central panel to form a
second tray, downwardly folding the retention flap, folding the
second tray over the first tray, and securing the second tray in a
closed position of the package by actuating the retention features
of the blank. Actuating the retention features comprises inserting
the locking portion of the retention flap in the opening.
[0008] In another aspect, the disclosure is generally directed to a
package for holding a food product. The package comprises a first
tray comprising a first central panel and at least two first side
panels foldably connected to the first central panel. The package
comprises a second tray comprising a second central panel and at
least two second side panels foldably connected to the second
central panel. An end panel is foldably connected to the first tray
and the second tray. A retention flap is foldably attached to at
least one of the first side panels. Retention features of the
package comprise a locking portion of the retention flap and an
opening in one of the second side panels. The locking portion is
shaped to be received in the opening and retain the second tray in
a closed position.
[0009] Other aspects, features, and details of the present
disclosure can be more completely understood by reference to the
following detailed description of exemplary embodiments taken in
conjunction with the drawings and from the appended claims.
[0010] The various features of the drawings discussed below are not
necessarily drawn to scale. Dimensions of various features and
elements in the drawings may be expanded or reduced to more clearly
illustrate the embodiments of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a plan view of an exterior side of a blank used to
form a package according to a first embodiment of the
disclosure.
[0012] FIG. 2 is a plan view of an interior side of the blank.
[0013] FIGS. 3 and 4 are perspectives of the package in a partially
assembled condition.
[0014] FIG. 5 is a perspective of the package.
[0015] Corresponding parts are designated by corresponding
reference numbers throughout the drawings.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0016] The package of the present disclosure is particularly useful
in containing a food product such as a piece of a frozen pizza
during storage of the pizza prior to consumption. Further, the
package of the present disclosure can be used for heating, cooking,
browning, crisping, etc. the food product by use of a heating or
cooking device such as a microwave oven. It is understood that food
products other than pizza may be contained in the package. Further,
food products contained in this package may be generally
triangular, round, square, rectangular, or any other shape. In this
specification, the terms "lower," "bottom," "upper" and "top"
indicate orientations determined in relation to fully erected and
upright packages.
[0017] FIG. 1 is a plan view of an exterior side 1 of a blank,
generally indicated at 3, used to form a package 5 (FIG. 5)
according to the exemplary embodiment of the disclosure. The
package 5 can be used to house a food product (e.g., a slice of
pizza, not shown). In the illustrated embodiment, the package 5 is
shaped to hold a single serving of pizza, which may be referred to
herein as a slice, but the package could be otherwise shaped to
hold correspondingly shaped food products. Further, the package 5
and blank 3 may be alternatively sized, shaped and/or otherwise
arranged to hold any number of food products including a single
food product or more than two food products. In the illustrated
embodiment, the package 5 is sized to hold a triangular slice of
pizza but the package may be otherwise sized and shaped for holding
one or more servings of pizzas. The package 5 is particularly
useful for holding the food product during storage in a freezer,
during heating and/or cooking in a microwave oven (not shown),
and/or during serving or consumption of the cooked food
product.
[0018] The blank 3 has a longitudinal axis L1 and a lateral axis
L2. In the illustrated embodiment, the blank 3 comprises a first
central panel 10 foldably connected to a first side panel 20 at a
first oblique fold line 21 and foldably connected to a second side
panel 30 at a second oblique fold line 31. The first side panel 20
is foldably connected to a retention flap 36 at an oblique fold
line 37. A notch 41 in the form of a cut or slit extends between
two portions of the oblique fold line 37 and at least partially
defines a locking portion 47 of the retention flap 36. The notch 41
has two transverse end portions 43 and an elongate portion 45
generally parallel to and spaced laterally inward from the fold
line 37. The notch 41 at least partially forms a retention feature
of the blank in the form of the locking portion 47 of the retention
flap 36. The second side panel 30 has a corner tab 51 foldably
attached to the side panel at an oblique fold line 53.
[0019] The first central panel 10 is foldably connected to an end
panel 57 at a lateral fold line 59. A first end tab 61 is foldably
connected to the end panel 57 at a first oblique fold line 63, and
a second end tab 67 is foldably connected to the end panel at a
second oblique fold line 69.
[0020] A second central panel 71 is foldably connected to the end
panel 57 at a lateral fold line 75. The second central panel 71 is
foldably connected to a first side panel 77 at a first oblique fold
line 79 and is foldably connected to a second side panel 81 at a
second oblique fold line 83. The first side panel 77 has an
elongate opening or slot 87 (e.g., cutout) generally parallel to
and extending between portions of the fold line 79. In the
illustrated embodiment, the elongate opening 87 comprises two
generally parallel edges 86, 88 and two rounded edges 90, 94
connecting the parallel edges. The opening 87 is positioned at a
location corresponding with a top edge of the second panel. The
edge 86 of the opening 87 is in the first side panel 77 and the
edge 88 of the opening is in the second central panel 71. The
rounded edges 90, 94 respectively extend from the edge 88 in the
second central panel 71 to the edge 86 in the first side panel 77.
A corner tab 89 is foldably connected to the second side panel 81
at an oblique fold line 91. The first side panel 77 and second side
panel 81 each have a notch 92, 93 in a respective edge of the side
panel. In the illustrated embodiment, the notches 92, 93 are in
respective longitudinal edges of the side panels 77, 81 and are
generally aligned in the longitudinal direction of the blank. It is
understood that the notches 92, 93 may be omitted or the notches
may be otherwise shaped, arranged, and located without departing
from the disclosure.
[0021] In the illustrated embodiment, the first central panel 10
includes at least one microwave energy interactive element 109
(FIG. 2) attached thereto (e.g., covering at least a portion of the
interior surface of the first central panel of the blank 3). In
accordance with the exemplary embodiment of the present disclosure,
the microwave energy interactive element 109 may comprise a
susceptor for becoming hot when exposed to microwave energy,
although other types and various combinations of microwave energy
interactive elements are also within the scope of the present
disclosure, as will be discussed below. Additionally, the blank 3
may include other microwave energy interactive elements overlying
one or more other panels, for example, the second central panel 71,
and/or one or more of the side panels 20, 30, 77, 81 and end panel
57. It also will be understood that the microwave energy
interactive element 109 may be omitted from the blank 3 without
departing from the scope of this disclosure.
[0022] In the illustrated embodiment, the elongate opening 87 has a
length L3 and a width W1, and the retention flap 47 has a length
L4. In one exemplary embodiment, the length L3 is at least
approximately 2.4 inches (61 mm), the width W1 is at least
approximately 1/8 inch (3.0 mm), and the length L4 is approximately
21/4 inches (57 mm). The dimensional information listed herein is
intended to be exemplary only and is not intended to limit the
scope of the disclosure. Further, the blank 3 may have dimensions
other than listed herein without departing from the disclosure.
[0023] In accordance with the exemplary embodiment, the blank 3 can
be erected into the package 5 by first folding along fold lines 21,
31, 79, 83 to upwardly fold the side panels 20, 30, 77, 81 relative
to the first and second central panels 10, 71. The corner tabs 51,
89 are respectively inwardly folded along fold lines 53, 91 so as
to be in generally face-to-face contact with a respective inner
surface of an opposite side panel 20, 77. The corner tabs 51, 89
may be respectively adhesively attached to one of the side panels
20, 77 by an adhesive such as glue. The retention flap 36 is
inwardly folded relative to the side panel 20 so that the retention
flap is generally parallel to the first central panel 10 and the
locking portion 47 is struck from and protrudes in a generally
horizontal direction relative to the side panel 20. In the
illustrated embodiment, the locking portion 47 of the retention
flap 36 is located at the top edge of the side panel 20 at a height
corresponding to the location of the oblique fold line 37. The
upwardly folded side panels 21, 30, 77, 81 and inwardly folded
corner tabs 51, 89 form generally opposed, triangular trays (e.g.,
first tray 113 and second tray 111) that are foldably connected to
opposite sides of the end panel 57. As shown in FIG. 4, the second
tray 111 is folded over the first tray 113, generally in the
direction of arrow A1, by folding along fold lines 59, 75 so that
the end panel 57 is in a generally vertical position. The second
tray 111 is further folded in the direction of arrow A1 so that the
side panels 77, 81 overlap and are in generally face-to-face
contact with the side panels 20, 30 of the first tray 113 to close
the package 5. When the second tray 111 is lowered over the first
tray 113, the locking portion 47 of the retention flap 36 is
received in the elongate slot 87 to secure the package 5 in the
closed position. The retention features of the blank (e.g., the
locking portion 47 and the elongate slot 87) releasably secure the
second tray 111 in the closed position covering the first tray 113.
The retention features may be positioned differently. For example,
the locking portion 47 may be positioned where the elongate slot 87
is shown, and the elongate slot 87 may be positioned where the flap
47 is shown. Alternatively, the first tray 113 may be arranged to
be lowered over the second tray 111 to secure the package 5 in the
closed position. Food product may be placed in the package 5 (e.g.,
in the first tray 113) at any point in the closing process.
Adhesive such as glue may be applied to one or more of the corner
tabs 51, 89, end tabs 61, 67, and side panels 20, 30, 77, 81 to
secure the second tray 111 in the closed position covering the
first tray 113. Further, an overwrap of plastic material or other
securement methods may be used to secure the second tray 111 in the
closed position covering the first tray 113.
[0024] To heat the food product in the package 5, in accordance
with one example, the package is opened by raising the second tray
111 from the closed position and the food product is removed from
the package and prepared for heating. To open the package 5, the
second tray 111 may be grasped by the notches 92, 93 in the side
panels 77, 81 and raised to allow access to the food product in the
package 5. For example, the food product may be a frozen pizza
slice that has a protective overwrap of plastic film or any other
suitable material that is removed from the pizza before heating.
The unwrapped pizza is placed in the first tray 113 against the
microwave energy interactive element 109 on the first central panel
10. After placing the pizza in the first tray 113, the second tray
111 can be closed in the manner discussed above and the package 5
placed in a microwave oven for heating the pizza. After heating,
the pizza may be removed from the package 5 by opening the package
in a similar manner as discussed above. Alternatively, the overwrap
may be omitted or it may cover the exterior of the package 5.
[0025] The package 5 may be used in a similar manner to heat and/or
cook a second food product that was originally packaged in the
package. Further, the package 5 may be used to reheat portions of
previously cooked pizzas, or the package may be used to heat food
products other than the pizzas originally packaged in the package,
without departing from the scope of this disclosure. The package 5
can be used as a serving plate for serving the cooked or heated
pizza slice. In one example, the second tray 111 can be removed by
tearing along fold line 75 (which may be formed as a tear line)
leaving the first tray 113 and end panel 57 forming a serving tray
for holding the cooked pizza slice. Furthermore, the second tray
111 can be removed from the package 5 before heating the pizza
slice in the microwave oven without departing from this
disclosure.
[0026] Various microwave energy interactive elements may be
suitable for use with the package 5 of the disclosure. For example,
the microwave energy interactive elements 109 (hereinafter
sometimes referred to as "microwave interactive element") may
promote browning and/or crisping of a particular area of the food
item, shield a particular area of the food item from microwave
energy to prevent overcooking thereof, or transmit microwave energy
towards or away from a particular area of the food item. Each
microwave interactive element comprises one or more microwave
energy interactive materials or segments arranged in a particular
configuration to absorb microwave energy, transmit microwave
energy, reflect microwave energy, or direct microwave energy, as
needed or desired for a particular construct and food item.
[0027] The microwave interactive element may be supported on a
microwave inactive or transparent substrate for ease of handling
and/or to prevent contact between the microwave interactive
material and the food item. As a matter of convenience and not
limitation, and although it is understood that a microwave
interactive element supported on a microwave transparent substrate
includes both microwave interactive and microwave inactive elements
or components, such constructs are referred to herein as "microwave
interactive webs".
[0028] The microwave energy interactive material may be an
electroconductive or semiconductive material, for example, a metal
or a metal alloy provided as a metal foil; a vacuum deposited metal
or metal alloy; or a metallic ink, an organic ink, an inorganic
ink, a metallic paste, an organic paste, an inorganic paste, or any
combination thereof. Examples of metals and metal alloys that may
be suitable for use with the present disclosure include, but are
not limited to, aluminum, chromium, copper, inconel alloys
(nickel-chromium-molybdenum alloy with niobium), iron, magnesium,
nickel, stainless steel, tin, titanium, tungsten, and any
combination or alloy thereof.
[0029] Alternatively, the microwave energy interactive material may
comprise a metal oxide. Examples of metal oxides that may be
suitable for use with the present disclosure include, but are not
limited to, oxides of aluminum, iron, and tin, used in conjunction
with an electrically conductive material where needed. Another
example of a metal oxide that may be suitable for use with the
present disclosure is indium tin oxide (ITO). ITO can be used as a
microwave energy interactive material to provide a heating effect,
a shielding effect, a browning and/or crisping effect, or a
combination thereof. For example, to form a susceptor, ITO may be
sputtered onto a clear polymeric film. The sputtering process
typically occurs at a lower temperature than the evaporative
deposition process used for metal deposition. ITO has a more
uniform crystal structure and, therefore, is clear at most coating
thicknesses. Additionally, ITO can be used for either heating or
field management effects. ITO also may have fewer defects than
metals, thereby making thick coatings of ITO more suitable for
field management than thick coatings of metals, such as
aluminum.
[0030] Alternatively, the microwave energy interactive material may
comprise a suitable electroconductive, semiconductive, or
non-conductive artificial dielectric or ferroelectric. Artificial
dielectrics comprise conductive, subdivided material in a polymeric
or other suitable matrix or binder, and may include flakes of an
electroconductive metal, for example, aluminum.
[0031] In one example, the microwave interactive element may
comprise a thin layer of microwave interactive material that tends
to absorb microwave energy, thereby generating heat at the
interface with a food item. Such elements often are used to promote
browning and/or crisping of the surface of a food item (sometimes
referred to as a "browning and/or crisping element"). When
supported on a film or other substrate, such an element may be
referred to as a "susceptor film" or, simply, "susceptor". However,
other microwave energy interactive elements, such as those
described herein, are contemplated hereby.
[0032] As another example, the microwave interactive element may
comprise a foil having a thickness sufficient to shield one or more
selected portions of the food item from microwave energy (sometimes
referred to as a "shielding element"). Such shielding elements may
be used where the food item is prone to scorching or drying out
during heating.
[0033] The shielding element may be formed from various materials
and may have various configurations, depending on the particular
application for which the shielding element is used. Typically, the
shielding element is formed from a conductive, reflective metal or
metal alloy, for example, aluminum, copper, or stainless steel. The
shielding element generally may have a thickness of from about
0.000285 inches to about 0.05 inches. In one aspect, the shielding
element has a thickness of from about 0.0003 inches to about 0.03
inches. In another aspect, the shielding element has a thickness of
from about 0.00035 inches to about 0.020 inches, for example, 0.016
inches.
[0034] As still another example, the microwave interactive element
may comprise a segmented foil, such as, but not limited to, those
described in U.S. Pat. Nos. 6,204,492, 6,433,322, 6,552,315, and
6,677,563, each of which is incorporated by reference in its
entirety. Although segmented foils are not continuous,
appropriately spaced groupings of such segments often act as a
transmitting element to direct microwave energy to specific areas
of the food item. Such foils also may be used in combination with
browning and/or crisping elements, for example, susceptors.
[0035] Any of the numerous microwave interactive elements described
herein or contemplated hereby may be substantially continuous, that
is, without substantial breaks or interruptions, or may be
discontinuous, for example, by including one or more breaks or
apertures that transmit microwave energy therethrough. The breaks
or apertures may be sized and positioned to heat particular areas
of the food item selectively. The number, shape, size, and
positioning of such breaks or apertures may vary for a particular
application depending on type of construct being formed, the food
item to be heated therein or thereon, the desired degree of
shielding, browning, and/or crisping, whether direct exposure to
microwave energy is needed or desired to attain uniform heating of
the food item, the need for regulating the change in temperature of
the food item through direct heating, and whether and to what
extent there is a need for venting.
[0036] It will be understood that the aperture may be a physical
aperture or void in the material used to form the construct, or may
be a non-physical "aperture". A non-physical aperture may be a
portion of the construct that is microwave energy inactive by
deactivation or otherwise, or one that is otherwise transparent to
microwave energy. Thus, for example, the aperture may be a portion
of the construct formed without a microwave energy active material
or, alternatively, may be a portion of the construct formed with a
microwave energy active material that has been deactivated. While
both physical and non-physical apertures allow the food item to be
heated directly by the microwave energy, a physical aperture also
provides a venting function to allow steam or other vapors to be
released from the food item. It also may be beneficial to create
one or more discontinuities or inactive regions to prevent
overheating or charring of the package.
[0037] As stated above, any of the above elements and numerous
others contemplated hereby may be supported on a substrate. The
substrate typically comprises for example, a polymer film or other
polymeric material. As used herein the term "polymer" or "polymeric
material" includes, but is not limited to, homopolymers,
copolymers, such as for example, block, graft, random, and
alternating copolymers, terpolymers, etc. and blends and
modifications thereof. Furthermore, unless otherwise specifically
limited, the term "polymer" shall include all possible geometrical
configurations of the molecule. These configurations include, but
are not limited to isotactic, syndiotactic, and random
symmetries.
[0038] The thickness of the film typically may be from about 35
gauge to about 10 mil. In one aspect, the thickness of the film is
from about 40 to about 80 gauge. In another aspect, the thickness
of the film is from about 45 to about 50 gauge. In still another
aspect, the thickness of the film is about 48 gauge. Examples of
polymeric films that may be suitable include, but are not limited
to, polyolefins, polyesters, polyamides, polyimides, polysulfones,
polyether ketones, cellophanes, or any combination thereof. Other
non-conducting substrate materials such as paper and paper
laminates, metal oxides, silicates, cellulosics, or any combination
thereof, also may be used.
[0039] In one example, the polymeric film comprises polyethylene
terephthalate (PET). Polyethylene terephthalate films are used in
commercially available susceptors, for example, the QWIKWAVE.RTM.
susceptor and the MICRORITE.RTM. susceptor laminations, both
available from Graphic Packaging International (Marietta, Ga.).
Examples of polyethylene terephthalate films that may be suitable
for use as the substrate include, but are not limited to,
MELINEX.RTM. films, commercially available from DuPont Teijan Films
(Hopewell, Va.), SKYROL films, commercially available from SKC,
Inc. (Covington, Ga.), and BARRIALOX PET films, available from
Toray Films (Front Royal, Va.), and QU50 High Barrier Coated PET
films, available from Toray Films (Front Royal, Va.).
[0040] The polymeric film may be selected to impart various
properties to the paper or paperboard web, for example,
printability, heat resistance, or any other property. As one
particular example, the polymeric film may be selected to provide a
water barrier, oxygen barrier, or a combination thereof. Such
barrier film layers may be formed from a polymer film having
barrier properties or from any other barrier layer or coating as
desired. Suitable polymer films may include, but are not limited
to, ethylene vinyl alcohol, barrier nylon, polyvinylidene chloride,
barrier fluoropolymer, nylon 6, nylon 6,6, coextruded nylon
6/EVOH/nylon 6, silicon oxide coated film, barrier polyethylene
terephthalate, or any combination thereof.
[0041] One example of a barrier film that may be suitable for use
with the present disclosure is CAPRAN.RTM. EMBLEM 1200M nylon 6
film, commercially available from Honeywell International
(Pottsville, Pa.). Another example of a barrier film that may be
suitable is CAPRAN.RTM. OXYSHIELD OBS monoaxially oriented
coextruded nylon 6/ethylene vinyl alcohol (EVOH)/nylon 6 film, also
commercially available from Honeywell International. Yet another
example of a barrier film that may be suitable for use with the
present disclosure is DARTEK.RTM. N-201 nylon 6,6 film,
commercially available from Enhance Packaging Technologies
(Webster, New York). Additional examples include BARRIALOX PET,
available from Toray Films (Front Royal, Va.) and QU50 High Barrier
Coated PET film, available from Toray Films (Front Royal, Va.),
referred to above.
[0042] Still other barrier films include silicon oxide coated
films, such as those available from Sheldahl Films (Northfield,
Minn.). Thus, in one example, a susceptor may have a structure
including a film, for example, polyethylene terephthalate, with a
layer of silicon oxide coated onto the film, and ITO or other
material deposited over the silicon oxide. If needed or desired,
additional layers or coatings may be provided to shield the
individual layers from damage during processing.
[0043] The barrier film may have an oxygen transmission rate (OTR)
as measured using ASTM D3985 of less than about 20 cc/m2/day. In
one aspect, the barrier film has an OTR of less than about 10
cc/m2/day. In another aspect, the barrier film has an OTR of less
than about 1 cc/m2/day. In still another aspect, the barrier film
has an OTR of less than about 0.5 cc/m2/day. In yet another aspect,
the barrier film has an OTR of less than about 0.1 cc/m2/day.
[0044] The barrier film may have a water vapor transmission rate
(WVTR) of less than about 100 g/m2/day as measured using ASTM
F1249. In one aspect, the barrier film has a water vapor
transmission rate of less than about 50 g/m2/day. In another
aspect, the barrier film has a WVTR of less than about 15 g/m2/day.
In yet another aspect, the barrier film has a WVTR of less than
about 1 g/m2/day. In still another aspect, the barrier film has a
WVTR of less than about 0.1 g/m2/day. In a still further aspect,
the barrier film has a WVTR of less than about 0.05 g/m2/day.
[0045] Other non-conducting substrate materials such as metal
oxides, silicates, cellulosics, or any combination thereof, also
may be used in accordance with the present disclosure.
[0046] The microwave energy interactive material may be applied to
the substrate in any suitable manner, and in some instances, the
microwave energy interactive material is printed on, extruded onto,
sputtered onto, evaporated on, or laminated to the substrate. The
microwave energy interactive material may be applied to the
substrate in any pattern, and using any technique, to achieve the
desired heating effect of the food item.
[0047] The microwave interactive element or microwave interactive
web may be joined to or overlie a dimensionally stable, microwave
energy transparent support (hereinafter referred to as "microwave
transparent support", "microwave inactive support" or "support") to
form the construct.
[0048] For example, the microwave energy interactive material may
be provided as a continuous or discontinuous layer or coating
including circles, loops, hexagons, islands, squares, rectangles,
octagons, and so forth. Examples of various patterns and methods
that may be suitable for use with the present disclosure are
provided in U.S. Pat. Nos. 6,765,182; 6,717,121; 6,677,563;
6,552,315; 6,455,827; 6,433,322; 6,414,290; 6,251,451; 6,204,492;
6,150,646; 6,114,679; 5,800,724; 5,759,422; 5,672,407; 5,628,921;
5,519,195; 5,424,517; 5,410,135; 5,354,973; 5,340,436; 5,266,386;
5,260,537; 5221,419; 5,213,902; 5,117,078; 5,039,364; 4,963,424;
4,936,935; 4,890,439; 4,775,771; 4,865,921; and Re. 34,683, each of
which is incorporated by reference herein in its entirety. Although
particular examples of patterns of microwave energy interactive
material are shown and described herein, it should be understood
that other patterns of microwave energy interactive material are
contemplated by the present disclosure.
[0049] In one aspect, for example, where a rigid or semi-rigid
construct is to be formed, all or a portion of the support may be
formed at least partially from a paperboard material, which may be
cut into a blank prior to use in the construct. For example, the
support may be formed from paperboard having a basis weight of from
about 60 to about 330 lbs/ream (i.e., lbs/3,000 ft.sup.2), for
example, from about 80 to about 140 lbs/ream. The paperboard
generally may have a thickness of from about 6 to about 30 mils,
for example, from about 12 to about 28 mils. In one particular
example, the paperboard has a thickness of about 18 mils and a
basis weight of from about 100 lbs/ream to about 300 lbs/ream. Any
suitable paperboard may be used, for example, a solid bleached or
solid unbleached sulfate board, such as SUS.RTM. board,
commercially available from Graphic Packaging International.
[0050] Furthermore, the blanks or other constructs may be coated
with, for example, a moisture and/or oxygen barrier layer, on
either or both sides, such as those described above. Any suitable
moisture and/or oxygen barrier material may be used in accordance
with the present disclosure. Examples of materials that may be
suitable include, but are not limited to, polyvinylidene chloride,
ethylene vinyl alcohol, DuPont DARTEK.RTM. nylon 6,6 film, and
others referred to above.
[0051] Alternatively or additionally, any of the blanks or other
constructs of the present disclosure may be coated or laminated
with other materials to impart other properties, such as
absorbency, repellency, opacity, color, printability, stiffness, or
cushioning. For example, absorbent susceptors are described in U.S.
Provisional Application No. 60/604,637, filed Aug. 25, 2004, and
U.S. patent application Ser. No. 11/211,858, to Middleton, et al.,
titled "Absorbent Microwave Interactive Packaging", filed Aug. 25,
2005, both of which are incorporated herein by reference in their
entirety. Additionally, the blanks or other constructs may include
graphics or indicia printed thereon. It will be understood that
with some combinations of elements and materials, the microwave
interactive element may have a grey or silver color that is
visually distinguishable from the substrate or the support.
However, in some instances, it may be desirable to provide a web or
construct having a uniform color and/or appearance. Such a web or
construct may be more aesthetically pleasing to a consumer,
particularly when the consumer is accustomed to packages or
containers having certain visual attributes, for example, a solid
color, a particular pattern, and so on. Thus, for example, the
present disclosure contemplates using a silver or grey toned
adhesive to join the microwave interactive elements to the
substrate, using a silver or grey toned substrate to mask the
presence of the silver or grey toned microwave interactive element,
using a dark toned substrate, for example, a black toned substrate,
to conceal the presence of the silver or grey toned microwave
interactive element, overprinting the metallized side of the web
with a silver or grey toned ink to obscure the color variation,
printing the non-metallized side of the web with a silver or grey
ink or other concealing color in a suitable pattern or as a solid
color layer to mask or conceal the presence of the microwave
interactive element, or any other suitable technique or combination
thereof.
[0052] As another example, the microwave interactive element may
comprise a microwave energy interactive insulating material. As
used herein, the term "microwave energy interactive insulating
material" or "insulating material" refers any combination of layers
of materials that is both responsive to microwave energy and
capable of providing some degree of thermal insulation when used to
heat a food item.
[0053] The insulating material may include various components,
provided that each is resistant to softening, scorching,
combusting, or degrading at typical microwave oven heating
temperatures, for example, at about 250.degree. F. The insulating
material may include both microwave energy responsive or
interactive components, and microwave energy transparent or
inactive components. For example, the insulating material may
comprise one or more susceptor layers in combination with one or
more expandable insulating cells. Additionally, the insulating
material may include one or more microwave energy transparent or
inactive materials to provide dimensional stability, to improve
ease of handling the microwave energy interactive material, and/or
to prevent contact between the microwave energy interactive
material and the food item. In one particular example, the
microwave energy interactive insulating material comprises a
microwave energy interactive material supported on a first
polymeric film layer, a moisture-containing layer superposed with
the microwave energy interactive material and a second polymeric
film layer joined to the moisture-containing layer in a
predetermined pattern, thereby forming one or more closed cells
between the moisture-containing layer and the second polymeric film
layer. The closed cells expand or inflate in response to being
exposed to microwave energy, and thereby causing microwave energy
interactive material to bulge and deform toward the food product.
In doing so, the heat generated by the microwave energy interactive
material is transferred to the food product more readily.
Additional benefits and aspects of such materials are described in
PCT Application No. PCT/US03/03779, U.S. application Ser. No.
10/501,003, and U.S. application Ser. No. 11/314,851, each of which
is incorporated by reference herein in its entirety.
[0054] The blank according to the present disclosure can be, for
example, formed from coated paperboard and similar materials. For
example, the interior and/or exterior sides of the blank can be
coated with a clay coating. The clay coating may then be printed
over with product, advertising, price coding, and other information
or images. The blank may then be coated with a varnish to protect
any information printed on the blank. The blank may also be coated
with, for example, a moisture barrier layer, on either or both
sides of the blank. In accordance with the above-described
embodiments, the blank may be constructed of paperboard of a
caliper such that it is heavier and more rigid than ordinary paper.
The blank can also be constructed of other materials, such as
cardboard, hard paper, or any other material having properties
suitable for enabling the package to function at least generally as
described herein. The blank can also be laminated or coated with
one or more sheet-like materials at selected panels or panel
sections.
[0055] In accordance with the above-described embodiments of the
present disclosure, a fold line can be any substantially linear,
although not necessarily straight, form of weakening that
facilitates folding therealong. More specifically, but not for the
purpose of narrowing the scope of the present disclosure, fold
lines may include: a score line, such as lines formed with a blunt
scoring knife, or the like, which creates a crushed portion in the
material along the desired line of weakness; a cut that extends
partially into a material along the desired line of weakness,
and/or a series of cuts that extend partially into and/or
completely through the material along the desired line of weakness;
and various combinations of these features.
[0056] The above embodiments may be described as having one or more
panels adhered together by glue during erection of the package
embodiments. The term "glue" is intended to encompass all manner of
adhesives commonly used to secure package panels in place.
[0057] The foregoing description of the disclosure illustrates and
describes various embodiments of the present disclosure. As various
changes could be made in the above construction without departing
from the scope of the disclosure, it is intended that all matter
contained in the above description or shown in the accompanying
drawings shall be interpreted as illustrative and not in a limiting
sense. Furthermore, the present disclosure covers various
modifications, combinations, and alterations, etc., of the
above-described embodiments that are within the scope of the
claims. Additionally, the disclosure shows and describes only
selected embodiments, but various other combinations,
modifications, and environments are within the scope of the
disclosure as expressed herein, commensurate with the above
teachings, and/or within the skill or knowledge of the relevant
art. Furthermore, certain features and characteristics of each
embodiment may be selectively interchanged and applied to other
illustrated and non-illustrated embodiments of the disclosure.
* * * * *