Note: Descriptions are shown in the official language in which they were submitted.
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REINFORCED POUCH
FIELD OF THE INVENTION
The present invention is generally related to packages or, more specifically,
to
reinforced pouches.
BACKGROUND
Reinforced pouches are widely used. There is always a desire for reinforced
pouches,
or components thereof, that provide a new balance of properties.
SUMMARY
In one aspect, this disclosure is directed to a package comprising a flexible
pouch at
least partially enwrapped by (and optionally joined to) a reinforcing sleeve.
The package can
be transitioned from a first, generally flattened configuration, to a second,
generally expanded
(e.g., erected) configuration. In the expanded configuration, the sleeve
provides structural
stability to the pouch and assists with maintaining the pouch in an open
condition so that
package may serve as a container for holding and accessing the food. Further,
in some
embodiments, the sleeve may also allow the package to be able to stand
substantially upright.
If desired, the package may be shaped to facilitate on-the-go consumption of
food
contained in the package (e.g., from fast food restaurants). For example, the
package may be
shaped and/or dimensioned so the package can be readily inserted into a cup
holder of an
automobile. As another example, the package may be shaped (e.g., contoured) to
facilitate
being held in the hand of a user.
In some embodiments, the package may also be used to at least one of heat,
brown,
and crisp the food, for example, in a microwave oven. In such embodiments, the
package may
include microwave energy interactive material that alters the effect of
microwave energy
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on the food. In one example, the microwave energy interactive material may be
configured
as a susceptor. When sufficiently exposed to microwave energy, the susceptor
tends to
absorb at least a portion of the microwave energy and convert it to thermal
energy (i.e., heat)
through resistive losses in the layer of microwave energy interactive
material. The remaining
microwave energy is either reflected by or transmitted through the susceptor.
Susceptors
often are used to promote browning and/or crisping of the surface of a food
item. However,
other microwave energy interactive elements may be used.
Such packages may be used to prepare various food items in a microwave oven,
for
example, pizza rolls, corn dogs, popcorn, snack bites, egg rolls, savory or
sweet pastries,
breaded food items, or any other generally food item that desirably is heated,
browned, and/or
crisped. The construct also may be suitable for use in a conventional oven.
The package may generally comprise disposable materials, such as paper,
paperboard,
and polymer films.
Regarding the package being in the form of a reinforced pouch, the reinforced
pouch
or package may be characterized as comprising a bag positioned in a carton,
wherein the
carton may be in the form of a sleeve extending around the bag, and the bag
may be mounted
to the sleeve. As a more specific example, the carton of the package may have
a plurality of
panels extending around an interior of the carton, wherein the plurality of
panels comprise,
consist essentially of, or consist of a pair of biconcave panels that are
opposite from one
another and each have opposite concave edges, and a pair of biconvex panels
that are
opposite from one another and each have opposite convex edges. The concave and
convex
edges may be respectively foldably connected to one another by arcuate fold
lines. When the
carton is in a fully erected configuration, each of the biconvex panels may be
in a
substantially concave configuration with respect to the interior of the
carton, wherein the
biconvex panels are retained in their substantially concave configurations in
response to
interplay between forces in the plurality of panels. As an example, the carton
optionally may
be in the form of a sleeve with opposite open ends that do not include (e.g.,
are not closed by)
end flaps, or the like, wherein the above-mentioned substantially concave
configurations of
the biconvex panels and/or the interplay between forces in the plurality of
panels maintains
the sleeve in its erected configuration, such that the sleeve (e.g., the
package as a whole) may
be able to stand upright on its own.
The foregoing presents a simplified summary of some aspects of this disclosure
in
order to provide a basic understanding. The foregoing summary is not extensive
and is not
intended to identify key or critical elements of the invention or to delineate
the scope of the
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invention. The purpose of the foregoing summary is to present some concepts of
this
disclosure in a simplified form as a prelude to the more detailed description
that is presented
later. For example, other aspects will become apparent from the following.
BRIEF DESCRIPTION OF THE DRAWINGS
Having described some aspects of this disclosure in general terms, reference
will now
be made to the accompanying drawings, which may be schematic and are not
necessarily
drawn to scale. The drawings are exemplary only, and should not be construed
as limiting
the invention.
Fig. 1A is a plan view of a first side (e.g., an exterior side) of an
exemplary blank for
forming a package.
Fig. 1B is a schematic plan view of a second side (e.g., an interior side) of
the blank
of Fig. 1A.
Fig. 1C is a schematic cross-sectional view of the exemplary blank of Fig. 1B,
taken
along line 1C-1C.
Figs. 1D and 1E are schematic plan views of opposite sides of a package formed
from
the blank of Figs. lA and 1B, in a substantially flattened configuration.
Figs. 1F-1H are schematic perspective views of the package of Figs. 1D and 1E
in a
substantially expanded, upright configuration.
DESCRIPTION
Exemplary embodiments of this disclosure are described below and illustrated
in the
accompanying figures, in which like numerals refer to like parts throughout
the several
views. The embodiments described provide examples and should not be
interpreted as
limiting the scope of the invention. Other embodiments, and modifications and
improvements of the described embodiments, will occur to those skilled in the
art and all
such other embodiments, modifications and improvements are within the scope of
the present
invention. For example, it will be apparent to those skilled in the art that
features illustrated
or described as part of one embodiment may be used in another embodiment to
yield a further
embodiment, and that these further embodiments are within the scope of the
present
invention.
Figs. lA and 1B schematically illustrate opposite (e.g., first and second)
sides of an
exemplary blank 100 that may be used to form a package 154 (Figs. 1D-1H). The
blank 100
generally includes a first component 102 and a second component 104 joined
(e.g., mounted)
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to one another. The first component 102 may comprise a flexible sheet of
material, for
example, paper, a polymer film, metallic foil, etc., that may be suitable for
forming a flexible
package, such as a pouch (e.g., a bag). The second component 104 may comprise
a
reinforcing sheet comprising a dimensionally stable and/or somewhat rigid or
stiff material
(e.g., paperboard) that may be suitable for being folded into a desired
structure and
substantially maintain its configuration, while providing some inherent degree
of flexibility
so that the panels of the second component can be moved or flexed as needed.
In this example, the first component or sheet 102 generally comprises a single
panel
or sheet of material, as shown schematically in Fig. 1B (which generally
illustrates an interior
side of the blank 100), and the second component or sheet 104 generally
comprises a plurality
of panels or portions joined along lines of weakening or disruption (e.g.,
fold lines), for
example, score lines, cut-crease lines, cut-space lines, tear lines, or any
other suitable lines of
weakening or disruption, or any combination thereof, as shown schematically in
Fig. 1A
(which generally illustrates an exterior side of the blank 100). However, in
other
embodiments, the first and/or second components 102, 104 of the blank 100 may
include a
fewer or greater number of panels, portions, pieces and/or lines of
disruption.
When the blank 100 is erected into the package 154, the flexible sheet 102
forms a
pouch (e.g., bag) for containing one or more items, and the dimensionally
stable sheet 104
defines a carton (e.g., a sleeve or sheath) that extends around the pouch to
provide structural
support and/or definition for at least a portion of the pouch. The
dimensionally stable sleeve
or sheath may also assist with maintaining the pouch in an open configuration,
as will be
discussed further below.
As shown in Figs. 1A and 1B, the first and second sheets 102, 104 of the blank
100,
the various panels of the sheets, and the blank 100 itself may each have a
first dimension, for
example, a length, extending in a first direction, for example, a longitudinal
direction, D1,
and a second dimension, for example, a width, extending in a second direction,
for example, a
transverse direction, D2, as generally measured as a distance between opposite
peripheral
edges of the blank, sheet, or panel. (It will be noted that such directional
designations are
made only for convenience and do not necessarily refer to or limit the manner
in which the
blank is manufactured or erected into the construct.) Peripheral edges of the
first sheet 102
may include a pair of peripheral edges 106, 108 extending in the longitudinal
direction D1
opposite one another, and top and bottom peripheral edges 110, 112 extending
in the
transverse direction D2 opposite one another, such that the first sheet 102
has a substantially
rectangular shape. Peripheral edges of the second sheet 104 may likewise
include a pair of
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peripheral edges 114, 116 extending in the longitudinal direction D1 opposite
one another,
and top and bottom peripheral edges 118, 120 extending in the transverse
direction D2
opposite one another, such that the second sheet 104 has a substantially
rectangular shape
(except that edge 114 is somewhat arcuate in shape while edges 116, 118, 120
are
substantially linear). However, other possibilities are contemplated.
The length and width of the first and second sheets 102, 104 may differ or may
be
substantially equal. For example, in the embodiment shown in the drawings, the
length Li of
the first sheet 102 is greater than the length L2 of the second sheet 104,
while the width W1,
W2 of the sheets 102, 104 may be approximately equal. The overall length L of
the blank
100 is the same as the length Li of the first sheet 102, and the overall width
W of the blank
100 is greater than the respective width W 1, W2 of the first sheet 102 or the
second sheet
104.
The first and second sheets 102, 104 may be separate from one another or may
be
joined to one another in any suitable manner and using any suitable technique
or material
(e.g., an adhesive). In this example, the first and second sheets 102, 104 are
joined so that the
second sheet 104 is substantially centered along the length Li of the first
sheet 102, and
offset from the first sheet 102 in the second direction D2. Accordingly, as
shown in Fig. 1A,
peripheral edges 114, 118, 120 of the second sheet 104 are in a facing,
contacting relationship
with the exterior side of the first sheet 102, while peripheral edge 116 is a
free edge that is not
joined to the first sheet 102. Peripheral edge 108 of the first sheet 102 is
in a facing,
contacting relationship with the interior side of the second sheet 104, while
peripheral edges
106, 110, 112 are free edges that are not joined to the second sheet 104. In
one example, the
sheets 102, 104 are mounted to one another by way of all of the surfaces of
the sheets 102,
104 that are at least generally in opposing face-to-face relation to one
another being joined to
one another by adhesive material. Notwithstanding and alternatively, typically
at least one of
the panels of the second sheet 104 is mounted to the first sheet 102 by
adhesive material or
any other suitable fastening technique. That is and for example, one or more
of the panels of
the second sheet 104 may not be mounted (e.g., directly adhered) to the first
sheet 102.
Viewing the components 102, 104 in greater detail now, the second sheet 104
(e.g.,
the dimensionally stable sheet 104) may include a first main panel 122, a
second main panel
124, a first minor panel 126, a second minor panel 128, and an attachment
panel 130 foldably
joined to one another, as shown schematically in Fig. 1A. The various panels
122, 124, 126,
128, 130 may be joined in a side by side relationship, so that panels 122,
124, 126, 128, 130
each include a pair of transverse peripheral edges opposite one another that
comprise a
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respective portion of peripheral edges 118, 120. Minor panel 126 includes a
longitudinal
peripheral edge 114 comprising peripheral edge 114 of the second sheet 104.
Similarly,
attachment panel 130 includes a longitudinal peripheral edge 116 comprising
peripheral edge
116 of the second sheet 104.
The first minor panel 126 and the second minor panel 128 are joined to
opposite
(generally longitudinal) edges of the first main panel 122 along lines of
disruption 132, 134.
The second minor panel 128 and attachment panel 130 are joined to opposite
(generally
longitudinal) edges of the second main panel 124 along lines of disruption
136, 138. The first
minor panel 126 and second minor panel 128 are each respectively divided into
a first portion
126a, 128a and a second portion 126b, 128b along respective lines of
disruption 140, 142
extending in the first direction Dl. The lines of disruption 140, 142
substantially bisect the
respective minor panel 126, 128 along its length Li. That is, for each minor
panel 126, 128
and its respective line of disruption 140, 142, the line of disruption is
positioned substantially
midway between the opposite convex edges of the minor panel.
Lines of disruption 132, 134, 136, 138, 140, 142 generally extend in the first
direction
D1 substantially between opposite transverse peripheral edges 118, 120 of the
second sheet
104, such that lines of disruption 132, 134, 136, 138, 140, 142 may each have
approximately
the same length L2. Likewise, panels 122, 124, 126, 128, 130 may have
approximately the
same length L2. However, in other embodiments, the dimensions of the various
panels and
lines of disruption may vary.
Lines of disruption 132, 134, 136, 138 are generally curved or arcuate in
shape, and
may be considered to be generally inwardly arcuate when viewed from the main
panels 122,
124, and generally outwardly arcuate when viewed along the minor panels 126,
128. As a
result, the first main panel 122 and second main panel 124 each have a
somewhat hourglass
or biconcave shape, such that the width of the respective main panel 122, 124
may be least
about halfway along its length L2. Conversely, the first minor panel 126 and
second minor
panel 128 each have a somewhat biconvex or barrel shape, such that the width
of the
respective minor panel 126, 128 may be greatest about halfway along its length
L2. In this
regard and in the embodiment shown in the drawings, the main panels 122, 124
(e.g.,
biconcave panels) each have opposite concave edges, and the minor panels 126,
128 (e.g.,
biconvex panels) each have opposite convex edges, and these concave and convex
edges are
respectively foldably connected to one another by the arcuate lines of
disruption 132, 134,
136, 138. However, other possibilities are contemplated.
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It will be noted that in the embodiment shown in the drawings, lines of
disruption
132, 134, 136, 138, 140, 142 are fold lines that comprise cut-space lines,
that is, a plurality of
spaced apart creases or partial depth cuts. However, any type of line of
disruption or
weakening may be used, for example, score lines, cut-crease lines, or
otherwise.
In some embodiments, the first and/or second sheets 102, 104 may comprise
microwave energy interactive material configured as one or more microwave
energy
interactive elements that alter the effect of microwave energy on an adjacent
food item. For
example, in one exemplary embodiment illustrated schematically in Fig. 1B, the
first sheet
102 may include microwave energy interactive material 144 (shown schematically
with
stippling) configured as a susceptor that operative for increasing in
temperature in response to
microwave energy. However, countless other possibilities are contemplated.
The microwave energy interactive material 144 (e.g., susceptor) may be
supported on
a polymer film 146 to define a susceptor film 148, as shown schematically in
Fig. 1C. The
outermost surface (i.e., the exposed surface) 150 of the polymer film 146 may
serve as a
food-contacting surface of the construct 154 (i.e., for being in facing,
substantially contacting
relationship with the food item) erected from the blank 100. The susceptor
film 148 may be
joined (e.g., laminated) to a support layer 152, for example, paper, using an
adhesive or
otherwise (not shown), to impart dimensional stability to the susceptor film
148 (and
resulting package 154) and/or to protect the layer of microwave energy
interactive material
144 from being damaged.
To form the package 154 (Figs. 1D-1G) from the blank 100 according to one
acceptable method, the blank 100 may be folded along lines of disruption 140,
142. Panels
126a, 130 may be overlapped with one another (e.g., so that peripheral edge
116 is
substantially aligned with line of disruption 140), and the peripheral margins
of the first
component 102 adjacent to peripheral edges 106, 108 may be overlapped with one
another.
The respective overlapping portions of the sheets 102, 104 may be joined to
one another in
any suitable manner, for example, using an adhesive, to form a substantially
flat, tubular
structure including an interior space 156 (shown in Figs. 1F and 1G) and a
pair of open ends
158, 160 e.g., end edges) defined by respective peripheral edges 110, 112 of
sheet 102. In
this folded flat configuration, the lines of disruption 132, 138 are
substantially superposed
with one another, and the lines of disruption 134, 136 are substantially
superposed with one
another.
If desired, at least one end of the structure (e.g., a peripheral margin along
end 160)
may be sealed (shown schematically with hatch marks in Figs. 1D and 1E) to
form a package
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or pouch 154 including one open end (e.g., end 158) and one closed end (e.g.,
end 160), with
the various lines of disruption 132, 134, 136, 138, 140, 142 extending along a
portion of the
length L of the construct 154.
The package 154 may be transitioned from this substantially flattened
configuration to
an open, expanded (e.g., erected) configuration by urging lines of disruption
140, 142
towards one another and/or moving panels 122, 124 away from one another, and
folding the
package 154 along lines of disruption 132, 134, 136, 138, 140, 142. At the
same time, panels
126, 128, 130 are moved inwardly so that the reinforcing sheath or sleeve 104
formed from
the second sheet 104 defines a contoured package shape with incurved sides.
The
intermediate lines of disruption 140, 142 are configured for allowing the
minor panels 126,
128 to be folded in a manner so that, for each minor panel, its opposite
convex edges may be
moved both toward and away from one another, for at least partially erecting
or unerecting
the incurved sides. Further regarding the incurved sides, they comprise each
of the minor
panels 126, 128 (e.g., biconvex panels) as a whole being in a substantially
concave
configuration with respect to the interior of the carton (e.g., sleeve) of the
package 154,
wherein the minor panels are retained in their substantially concave
configurations at least
partially in response to interplay between forces in the carton of the package
154. Optionally,
the package 154 being held by hand or placed in a cup holder, or the like, may
also help to at
least partially retain the minor panels 126, 128 in their substantially
concave configurations.
In the embodiment shown in the drawings, the carton of the package 154 has
opposite open
ends that do not include, and are not closed by, end flaps of the carton,
wherein the above-
mentioned substantially concave configurations of the panels 126, 128 and/or
the interplay
between forces in the carton of the package 154 maintain the carton in its
erected
configuration. However, the package may be configured to have any other shape,
for
example, a somewhat tubular or cylindrical shape, a somewhat rectangular
shape, or any
other regular or irregular shape. As another example and optionally, the
carton or sleeve of
the package may further include one or more end flaps for at least partially
closing one or
both of the ends of the carton or sleeve.
If desired, the package 154 may be brought into an upright configuration with
the
closed end 160 of the package facing downwardly, as shown schematically in
Figs. 1F and
1G. In this configuration, panels 122, 124, 126, 128, 130 (some of which are
hidden from
view in Figs. 1F and 1G) provide structural stability for the flexible pouch
102 and assist with
maintaining the pouch in an open configuration so the food or other package
contents can be
readily accessed, even when the food is being consumed on the go.
Additionally, the
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incurved portions of the reinforcing sleeve 104 define a curved outer surface
of the package
that facilitates grasping of the package.
As shown for example in Fig. 10, the carton portion of the package 154 is in
the form
of a sleeve having opposite top and bottom ends; the bag portion of the
package is positioned
in the interior of the sleeve; the top end of the bag extends upwardly,
outwardly through an
opening of the top end of the sleeve; the sealed closed bottom end of the bag
extends
downwardly, outwardly through an opening of the bottom end of the sleeve; and
the top and
bottom ends of the bag are wider than the sleeve.
If desired, the bottom portion of the pouch 102 may be urged upwardly, so that
peripheral edge 120 becomes a lowermost portion of the package 154, as shown
schematically in Fig. 1H. In this manner, peripheral edge 120 may serve as a
bottom edge for
supporting the package when placed on a surface.
A food item may be inserted into the interior space 156 at any suitable time
and the
open end of the package may be sealed. Alternatively, one end may remain
unsealed and the
user may be instructed to insert the food into the interior space prior to
use.
If the package is used for microwave heating, browning, and/or crisping, the
food
item within the interior space 156 may be exposed to microwave energy. Upon
sufficient
exposure to microwave energy, the microwave energy interactive material (i.e.,
susceptor
144) converts at least a portion of the impinging microwave energy into
thermal energy,
which then may be transferred to the surface of the food item. As a result,
the heating,
browning, and/or crisping of the food item may be enhanced. Notably, the
somewhat tubular
shape of the package 154 allows multiple sides of a food item to be heated,
browned, and/or
crisped concurrently without having to reposition the food item during the
heating cycle.
In some embodiments, the package 154 may be pre-expanded to fit the package
contents or to provide a void volume within the interior space 156 to
accommodate the
expansion of the food during heating. It is also contemplated that the package
154 may
expand further during heating, for example, in response to the expansion of
the food (e.g.,
popcorn).
It will be evident that since the package 154 may be configured in a variety
of ways,
the package may likewise be characterized in a variety of ways. For example,
the package
154 may be characterized as a pouch 102 with a reinforced portion 104, or as a
package 154
with a flexible portion 102 and a dimensionally stable portion 104.
Alternatively, the
package 154 may be characterized as a carton or container 104 with a flexible
liner 102.
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Thus, the use of different terminology to describe the package or its
components or features
should not be limiting in any manner.
Countless materials may be used to form packages according to this disclosure.
For
example, the first component 102 of the blank 100 (i.e., the flexible portion
of the package
154) may comprise any suitable flexible material. For example, the second may
comprise
paper, a polymer film, metallic layer, or any combination thereof. The paper
may have a
basis weight of from about 15 to about 60 lb/ream (1b/3000 sq. ft.), for
example, from about
20 to about 40 lb/ream, for example, about 25 lb/ream. Suitable polymer films
may have a
caliper of from about 0.5 mil to about 2 mil. Composites of paper, film,
and/or other
materials also may be used. Such composites may have a caliper of for example,
from about
1.5 to about 5 mils, for example, about 3 mils.
The second component 104 of the blank 100 (i.e., the reinforcing portion of
the
package 154) may comprise a dimensionally stable and/or semi-rigid material,
such as
paperboard. The paperboard may have a basis weight of from about 60 to about
330 lb/ream,
for example, from about 80 to about 140 lb/ream. The paperboard generally may
have a
thickness of from about 6 to about 30 mils, for example, from about 8 to about
24 mils. In
one particular example, the paperboard has a thickness of from about 12 to
about 14 mils.
Any suitable paperboard may be used, for example, a solid bleached sulfate
board, for
example, Fortress board, commercially available from International Paper
Company,
Memphis, TN, or solid unbleached sulfate board, such as SUS board,
commercially
available from Graphic Packaging International, Marietta, GA.
As mentioned above, the microwave energy interactive material 144 (shown
schematically with stippling) may be configured as a susceptor, so that the
package 154 may
be used to at least one of heat, brown, and crisp the food, for example, in a
microwave oven.
In such embodiments, the package may include microwave energy interactive
material that
alters the effect of microwave energy on the food. When the microwave energy
interactive
material 144 is in the form of a susceptor, it may be configured as a thin
layer of microwave
energy interactive material generally less than about 100 angstroms in
thickness, for example,
from about 60 to about 100 angstroms in thickness, and having an optical
density of 0.15 to
about 0.35, for example, about 0.17 to about 0.28. When sufficiently exposed
to microwave
energy, the susceptor tends to absorb at least a portion of the microwave
energy and convert
it to thermal energy (i.e., heat) through resistive losses in the layer of
microwave energy
interactive material. The remaining microwave energy is either reflected by or
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through the susceptor. Susceptors often are used to promote browning and/or
crisping of the
surface of a food item. However, other microwave energy interactive elements
may be used.
Where used, the microwave energy interactive material may comprise an
electroconductive or semiconductive material, for example, 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 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.
Alternatively, the microwave energy interactive material may comprise a metal
oxide,
for example, oxides of aluminum, iron, and tin, optionally used in conjunction
with an
electrically conductive material. Another metal oxide that may be suitable is
indium tin
oxide (ITO). ITO has a more uniform crystal structure and, therefore, is clear
at most coating
thicknesses.
Alternatively still, 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.
In other embodiments, the microwave energy interactive material may be carbon-
based, for example, as disclosed in U.S. Patent Nos. 4,943,456, 5,002,826,
5,118,747, and
5,410,135.
In still other embodiments, the microwave energy interactive material may
interact
with the magnetic portion of the electromagnetic energy in the microwave oven.
Correctly
chosen materials of this type can self-limit based on the loss of interaction
when the Curie
temperature of the material is reached. An example of such an interactive
coating is
described in U.S. Patent No. 4,283,427.
As stated above, the microwave energy interactive material (e.g., microwave
energy
interactive material 144) may be supported on a polymer film (e.g., polymer
film 146). The
thickness of the film typically may be from about 35 gauge to about 10 mil,
for example,
from about 40 to about 80 gauge, for example, from about 45 to about 50 gauge,
for example,
about 48 gauge. Examples of polymer films that may be suitable include, but
are not limited
to, polyolefins, polyesters, polyamides, polyimides, polysulfones, polyether
ketones,
cellophanes, or any combination thereof In one specific example, the polymer
film may
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comprise polyethylene terephthalate (PET). Examples of PET films that may be
suitable
include, but are not limited to, MELINEXO, commercially available from DuPont
Teijan
Films (Hopewell, Virginia), SKYROL, commercially available from SKC, Inc.
(Covington,
Georgia), and BARRIALOX PET, available from Toray Films (Front Royal, VA), and
QU50
High Barrier Coated PET, available from Toray Films (Front Royal, VA). The
polymer film
may be selected to impart various properties to the microwave interactive web,
for example,
printability, heat resistance, or any other property. As one particular
example, the polymer
film may be selected to provide a water barrier, oxygen barrier, or any
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.
If desired, the polymer film may undergo one or more treatments to modify the
surface prior to depositing the microwave energy interactive material onto the
polymer film.
By way of example, and not limitation, the polymer film may undergo a plasma
treatment to
modify the roughness of the surface of the polymer film. While not wishing to
be bound by
theory, it is believed that such surface treatments may provide a more uniform
surface for
receiving the microwave energy interactive material, which in turn, may
increase the heat
flux and maximum temperature of the resulting susceptor structure. Such
treatments are
discussed in U.S. Patent Application Publication No. 2010/0213192 Al,
published August
26, 2010.
Other non-conducting substrate materials such as paper and paper laminates,
metal
oxides, silicates, cellulosics, or any combination thereof, also may be used.
If desired, the susceptor may be used in conjunction with other microwave
energy
interactive elements and/or structures. Structures including multiple
susceptor layers are also
contemplated.
By way of example, the susceptor may be used with a foil or high optical
density
evaporated material having a thickness sufficient to reflect a substantial
portion of impinging
microwave energy. Such elements typically are formed from a conductive,
reflective metal
or metal alloy, for example, aluminum, copper, or stainless steel, in the form
of a solid
"patch" generally having a thickness of from about 0.000285 inches to about
0.005 inches,
for example, from about 0.0003 inches to about 0.003 inches. Other such
elements may have
a thickness of from about 0.00035 inches to about 0.002 inches, for example,
0.0016 inches.
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In some cases, microwave energy reflecting (or reflective) elements may be
used as
shielding elements where the food item is prone to scorching or drying out
during heating. In
other cases, smaller microwave energy reflecting elements may be used to
diffuse or lessen
the intensity of microwave energy. One example of a material utilizing such
microwave
energy reflecting elements is commercially available from Graphic Packaging
International,
Inc. (Marietta, GA) under the trade name MicroRitee packaging material. In
other examples,
a plurality of microwave energy reflecting elements may be arranged to form a
microwave
energy distributing element to direct microwave energy to specific areas of
the food item. If
desired, the loops may be of a length that causes microwave energy to
resonate, thereby
enhancing the distribution effect. Examples of microwave energy distributing
elements are
described in U.S. Patent Nos. 6,204,492, 6,433,322, 6,552,315, and 6,677,563.
In still another example, the susceptor may be used with or may be used to
form a
microwave energy interactive insulating material. Examples of such materials
are provided
in U.S. Patent No. 7,019,271, U.S. Patent No. 7,351,942, and U.S. Patent
Application
Publication No. 2008/0078759 Al, published April 3, 2008.
If desired, any of the numerous microwave energy 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. The breaks or apertures
may extend
through the entire structure, or only through one or more layers. The number,
shape, size,
and positioning of such breaks or apertures may vary for a particular
application depending
on the type of construct being formed, the food item to be heated therein or
thereon, the
desired degree of heating, 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.
By way of illustration, a microwave energy interactive element may include one
or
more transparent areas to effect dielectric heating of the food item. However,
where the
microwave energy interactive element comprises a susceptor, such apertures
decrease the
total microwave energy interactive area, and therefore, decrease the amount of
microwave
energy interactive material available for heating, browning, and/or crisping
the surface of the
food item. Thus, the relative amounts of microwave energy interactive areas
and microwave
energy transparent areas must be balanced to attain the desired overall
heating characteristics
for the particular food item.
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As another example, one or more portions of the susceptor may be designed to
be
microwave energy inactive to ensure that the microwave energy is focused
efficiently on the
areas to be heated, browned, and/or crisped, rather than being lost to
portions of the food item
not intended to be browned and/or crisped or to the heating environment.
Additionally or
alternatively, it may be beneficial to create one or more discontinuities or
inactive regions to
prevent overheating or charring of the food item and/or the construct
including the susceptor.
By way of example, the susceptor may incorporate one or more "fuse" elements
that limit the
propagation of cracks in the susceptor structure, and thereby control
overheating, in areas of
the susceptor structure where heat transfer to the food is low and the
susceptor might tend to
to become too hot. The size and shape of the fuses may be varied as needed.
Examples of
susceptors including such fuses are provided, for example, in U.S. Patent No.
5,412,187, U.S.
Patent No. 5,530,231, U.S. Patent Application Publication No. US
2008/0035634A1,
published February 14, 2008, and PCT Application Publication No. WO
2007/127371,
published November 8, 2007.
In the case of a susceptor, any of such discontinuities or apertures may
comprise a
physical aperture or void in one or more layers or materials used to form the
structure or
construct, or may be a non-physical "aperture". A non-physical aperture is a
microwave
energy transparent area that allows microwave energy to pass through the
structure without
an actual void or hole cut through the structure. Such areas may be formed by
simply not
applying microwave energy interactive material to the particular area, by
removing
microwave energy interactive material from the particular area, or by
mechanically
deactivating the particular area (thereby rendering the area electrically
discontinuous).
Alternatively, the areas may be formed by chemically deactivating the
microwave energy
interactive material in the particular area, thereby transforming the
microwave energy
interactive material in the area into a substance that is transparent to
microwave energy (i.e.,
microwave energy inactive). 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 or liquid released from the
food item to be
carried away from the food item.
As stated above, the susceptor film (e.g., susceptor film 148) (and/or other
microwave
energy interactive elements) may be joined to a flexible support layer (e.g.,
support 152), for
example, paper, a polymer film, or other suitable material, as described
above.
While the present invention is described herein in detail in relation to
specific aspects
and embodiments, it is to be understood that this detailed description is only
illustrative and
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exemplary of the present invention and is made merely for purposes of
providing a full and
enabling disclosure of the present invention and to set forth the best mode of
practicing the
invention known to the inventors at the time the invention was made. The
detailed
description set forth herein is illustrative only and is not intended, nor is
to be construed, to
limit the present invention or otherwise to exclude any such other
embodiments, adaptations,
variations, modifications, and equivalent arrangements of the present
invention. All
directional references (e.g., upper, lower, upward, downward, left, right,
leftward, rightward,
top, bottom, above, below, vertical, horizontal, clockwise, and
counterclockwise) are used
only for identification purposes to aid the reader's understanding of the
various embodiments
of the present invention, and do not create limitations, particularly as to
the position,
orientation, or use of the invention unless specifically set forth in the
claims. Joinder
references (e.g., joined, attached, coupled, connected, and the like) are to
be construed
broadly and may include intermediate members between a connection of elements
and
relative movement between elements. As such, joinder references do not
necessarily imply
that two elements are connected directly and in fixed relation to each other.
Further, various
elements discussed with reference to the various embodiments may be
interchanged to create
,
entirely new embodiments coming within the scope of the present invention.
The above examples are in no way intended to limit the scope of the present
invention. It will be understood by those skilled in the art that while the
present disclosure
has been discussed above with reference to exemplary embodiments, various
additions,
modifications and changes can be made thereto without departing from the scope
of the
invention as set forth in the claims.
