Note: Descriptions are shown in the official language in which they were submitted.
~g2/2247~ 2 1 1 1 3 2 8 Pcr/Us92~049ss
MICROWAVABLE FOOD PACKAGE ~AVING A BAG WITH REVERSE FOLDED GlISSETS
FT~T n OF ~T~F TNV~NTION
The present invention relates to microwave food
products, and more particularly to bags containing popping
corn .
BACKGRO~D OF ~ INV~TION
Currently available popcorn intended for cooking
in a microwave oven is usually packaged in a two-ply paper
bag, which may have a flat bottom or a wedge-shaped
bottom. The bag contains a charge of edible ingredients,
10 usually including corn 3cernels, shortening and sometimes
seasoning or f lavoring .
The bags are first formed in a bag-making plant
and are later filled as part of a separate operation,
usually at a different location. The bags should there-
15 fore be readily stackable, shipable and be handleable ina F-^hAn1 ~ed manner.
Since the volume of popped corn is vastly
greater than that of the unpopped kernels, the container
must have the ability to expand during cooking. For this
20 reason, the bag is capable of unfolding under the internal
pressure of the steam released by the exploding kernels
and the pressure of the ~ n-l i n~ kernels themselves .
Bags of this type are described in U. S. Patents Nos.
4,571,337 (Cage et al.) and 3,851,574 (Katz et al.).
25 Although these patents show bags with flat bottoms, bags
with wedge-shaped bottoms are presently more common.
The conf iguration and construction of the bag
should help to maximize the "pop volume" of the corn. Not
only does increased pop volume result in a larger volume
30 of edible product (both real and perceived), but it has
been found that increased pop volume results in a lighter,
fluffier popcorn product with improved textural qualities.
.,' ~
WO 92~2247S
~ 2 2~.11328
! In general, bags with wedge-shaped bottoms
containing ready-to-pol? corn are of either pinched bottom
or tube construction. These two types of bags are similar
in most respects, the bottom being formed by bonding
5 toqether the front ancl back panels of the bag at their
bottom edges. There is thus no separate bottom panel. A
typical bag mzy inclul~e a seamless and generally flat
front panel, a generally flat back panel with an over-
lapping seam running its full length at or near its
lO center, and two side panels that connect the front and
back panels. The side panels are each folded inwardly to
f orm a gusset that permits the bag to expand . In a
pinched bottom bag the sealed bottom edge is folded over
itself, whereas in a tube bag there is no such fold at the
15 bottom.
In a typical ready-to-pop bag the edible charge
is placed inside the bag, resting on a susceptor that is
contiguous with a center section of the front panel. The
bag is sealed at the top after filling by bonding together
20 the top edges of the front and back panels. The gussets
of the folded bag intrude well into the bag interior,
extending between at least some portion of the charge and
the back panel. Since the upper and lower sections of the
bag remain essentially empty, they are easily f lattened
25 and folded over the more bulky center section.
When the still folded bag is to be used, it is
placed inside the oven with the center section of the
front panel resting on the oven floor, 50 that the charge
rests on the susceptor and the gussets of the side panels
30 overlay a portion of the charge. During cooking, the
internal pressure of the steam released by the kernels and
the pressure of the pop3?ed kernels themsclves cause the
two end sections of the oag to unfold gradually.
A typical popcorn bag may, however, yield less
_, _ _ _ _, ,,,,,, , . ., ., :: ~ . ,, _ _ _
WO 92/22475 - - PCr/US92~04955
3 2i11328
than the maximum possible pop volume. This common
deficiency in bag performance can be attributable, at
least in part, to the configuration of the bag and to such
factors as the size an~ stiffness of the gussets.
The gussets intrude into the bag to the greatest
extent when the bag is folded flat and the gussets are
closed. A6 the cooking -n~ the gussets define a
relatively narrow chamlel between them, which widens as
the cooking progresses and the bag expands. The popped
kernels must pass through this channel to move vertically
into the upper section of the bag. Consequently some of
the kernels that are among the f irst to pop are f orced to
move laterally a considierable distance toward the center
of the bag bef ore they can move upwardly away f rom the
susceptor.
In addition, some kernels break loose from the
charge prior to or durillg cooking and lodge themselves in
the folds between the panels and the gussets. In many
instances the gussets clo not open suf f iciently or early
enough to release these kernels and allow them to pop
properly .
The opening of the gussets as the bag expands is
essential to freeing the trapped kernels, but does not, in
itself, assure that these kernels return to the susceptor
and the center of the bag. The loose kernels are, how-
ever, prompted to so move by any rounding of the front
panel (on which the bag rests during cooking1 that takes
place and by the shaking movement of the bag caused by the
exploding kernels. The more pronounced the ~;ULVaLULt: of
the front panel, the more tendency the kernels will have
to move toward the susceptor.
WO 92/22475 PCr/US92/0~955
4 21111 32~ '--
5UMMARY OF TEIE I~VENTIoN
The present invention provides a microwave f ood
product comprising an edible charge of popping corn and an
PYr lnAAhle bag containing that charge. The improved
5 design of the bag decreases the number of ~ JYYP~1 kernels
and increases the pop volume, thus improving the textural
qualities of the corn.
The bag is pre~erably made of paper. It may
have an inner layer of non-wicking greaseproof paper and
10 an outer layer of kraft paper, or it may be of single ply
construction. The paper used should have dimensional
stability and should be flexible, yet sufficiently stiff
to maintain an PyrAnApd 6hape and keep the bag from
sagging or drooping after the corn has popped.
The bag can have generally flat front and back
panels, and two 6ide panels folded inwardly to ~orm
gus6ets. Advantageously, each side panel forms two or
more gussets. This multiple gusset construction, with
each gusset being smaller, results in a larger channel at
2 0 the center of the bag between the gussets that permits
relatively f ree upward ~ of the corn as the bag
expands. In addition, the multiple gusset construction
allows the bag to expand mOrQ fully and with less resis-
tance. The6e features of the bag promote increa6ed pop
25 volume.
According to another aspect of the invention,
the bag can be f ormed in such a manner that the gusset
ends , i . e ., the corners at the ends of the gussets , are
each inAPrPnAPntly movable. The resulting bag i5 thus
30 more easily PY~AnA~d during cooking and takes on a more
rounded shape . Its rounded bottom surf ace promotes
desirable rocking movement durinq cooking. The features
of multiple gussets and ; nAPrPnAPntly movable gusset ends
W`O 92~22475 PCr/US92/04955
.
can be advantageously combined in a single lg ~co promote
the highest pop volume and best textural qualities of the
corn .
An alternati ve bag construction has a pinched
5 bottom conf iguration . The gusset ends at the bottom of
this bag are not in~PrenrlPntly movable, but the bag
retains many other advantages of multiple gusset
construction. still another multiple gusset bag has a
flat bottom, the side panels being scored to define
10 triangular and trapezoidal areas near the bottom end.
In one f orm of the invention the back panel of
the bag, in the collapsed configuration, is folded so as
to expose a portion of each side panel that forms at least
one gusset. The back panel is thus folded along fold
15 lines, thereby defining strips extending along each side
edge of the bag in which the bag has a thickness of four
layers. A center section of the bag between the strips
has a lesser thickness.
Other f eatures and advantages of the present
20 invention will become apparent from the following detailed
description, taken in conjunction with the accompanying
drawings which illust~-ate, by way of example, the
principles of the invention.
BRIEF DESCRIPTION OF TE~E DRAWINGS
FIG. 1 is a perspective view of an llnp~r~nr~ed
bag of ready-to-pop popcorn when f irst placed in a micro-
wave oven;
FIG. 2 is a cross-sectional view of the bag of
FIG. 1 and contents taken along a line 2-2;
FIG. 3 is a perspective view of the bag of FIG.
~7-
~o 92/22475 G 2 1 1 1 3 2 8 PCT/US92/04955
1 in the early stages o~ cookillg and in a partially
condition;
PIG. 4 i9 a cros~-sectional view of the bag of
Fig. 1 and its contents taken along a line 4-4 of FIC~. 3;
FIG, 5 is a perspective view of the bag of fig. 1
After full expansion;
FIG. 6 is a cross sectional view of the P~n~lPd
bag and contents taken along line 6-6 of FIG. 5;
FIG. 7 is a perspective of an alternative bag
construction, having reverse folded gussets, shown in an
p~n~-d condition;
FIG. 8 is an end view of the llnP~n~ d bag of
FIG. 7;
FIG. 9 is a perspective view of an alternative
pinched bottom bag consturction, shown in an expanded
condition;
FIG. 10 is a persepctive view of another
alternative bag, of ~lat bottom construction, Ghown in a
partially expanded condition; and
FIG. 11 is a perspective view of the bag of FIG.
10, shown in a fully expanded condition.
FIG. 12 is an enlarged view of a portion o~ the
bag of FIG 8 shown in a partially collapsed conf iguration.
DES~RTPTION OF T~ 'K~ KK~I) El~q~Qr)IME~TS
An exemplary microwave food product made in
accordance with the present invention (shown in FIGS. 1
through 6) consists of an edible charge of popcorn and
shortening 10, packed in a bag 12. The bag 12 serve~3 as a
cooking c~nt~ ~ nPr and can function as a convenient
WO 92/22475 PCr/US92/04955
serving vessel as well. 21113 2 ~
The bag 12 is formed from a sheet of single-ply,
machine-finished kraft paper treated with a commercially
available fluuLo~ Lbu-. stain inhibitor. Machine glazed
5 papers are also suit.able, but more rigid. More
.:ssed papers such as grease proof and gl ~ ; ne are
not as desirable. The desired paper weight is 35-60 lbs.,
preferably about 40 lbs. This preferred weight is less
than the total weight of the two plies of bags that are in
lO common use. Lighter paper is conducive to freer bag
expansion and improved pop volume, but the paper must be
heavy enough to avoid tearing during the bag making and
filling processes, and ~ufficiently stiff to maintain the
desired ~s~p~nAeA shape.
It is also possible to use a bag 12 of two ply
construction, as is common today. Preferably the inner
layer is then of 20-25 ll~. greaseproof paper and the outer
layer is of 20-30 lb. machine finished paper.
The bag 12 ha6 a generally flat seamless front
20 panel 14, a generally flat back panel 16 of the same size
with an overlapping seam 18 running the length of that
panel (usually at or near its center~. Two side panels 20
and 22, each having two inwardly folding gussets, 20a and
20b, or 22a and 22b, respectively. Each gusset is defined
25 by fold lines that defir,e generally elongated rectangular
upper and lower sections. The multiple gussets thus have
a pleated or accordion-like conf iguration with a natural
resilience or spring-like qualilty, causing the bag 12 to
expand readily and with reduced reqistance. Thi~
30 resiliency of the bag 12 is one of the features that can
contribute to improved p~p volume.
The general conf iguration of the bag 12 is that
of a tube closed a ' either end by seams f ormed by bonding
_ _ _ _ _ _ _ _ _ _ ... . ... . . . . ..
Wo 92/22475 8 2111328 P~T/US92/04955
together the inner surfaces at thé edges of the front and
back panels 14 and 16, and by bonding together the inner
surfaces at the edges of the folds in the side panels 20 and
22 . Arrorrl~ n~ly, the bag 12 can be said to have a wedge-
3haped bottom. The two gussetd (20a and 20b, or 22a and
22b) on each side are of equal size. The gussets of each
side panel 20 and 22 are separable along their full length,
and the gusset ends or corners 23 at both endd of the bag 12
are thus free to move independently and to separate from
each other when the bag is ~n~ d~ as shown in FIG. 5.
Preferably the seam 18 is not located in the gussets where
it could rigidify the bag 12 and inhibit free unfolding
~v~ .
A susceptor 2 8 is coextensive with the inside of
a center section 30 of the bag 12 and is bonded to the
expo~ed inner surface of the bag by a suitable a&esive such
as Duraset 12 or Airflex 421 (Air Products & Chemicals,
Inc.). In the case of a two ply bag, the susceptor 28 may
instead be positioned between the plies of the front panel
14.
When the bag 12 is filled, the edible charge 10
is deposited on the susceptor 28. The lower gussets are
then folded inwardly along the fold lines 74 and the upper
gussets are reversed folded outwardly by pivoting portions
of the back panel along the reverse fold lines 52, thereby
closing the lower gusaets, opening the upper gussets and
flattening the bag 12. The top end 30 of the bag 12 is
sealed by applying ~uf f icient heat and pressure across the
front panel 14 and the back panel 16 to activate a strip of
heat seal coating (not shown( applied to the inner
circumference of the bag, bonding together the top edges of
the front panel 14 and the rear panel 16. An empty top
section 32 and a bottom ~ection 34, ad~acent a middle
section 35, are then folded transversely to the longitudinal
axis of the bag 12, on top of the back panel 16 of the
middle ~ection 35. It i~ preferable that the bag 12 be
folded symmetrically 80 that the top and bottom sections
WO 92/22475 PCr/US92/04955
g
32 and 34 are of the same size. 21~13 2 8
Any corn that becomes trapped on top of the
gussets (20a and b and 22a and b) most likely will not pop
as well, or possibly not at all, resulting in reduced pop
5 volume and inferior textural qualities. It should be
noted however, that, in comparison to a conventional
single gus6et bag, it is relatively easy to prevent the
charge 10 from being deposited on top of the gussets (20a
and b and 22a and b) when filling the bag 12. These
10 gussets intrude into tlle bag 12 only about half as far as
would a single gusset (See FIG. 4).
It is also i~iportant during cooking that the use
of multiple gussets l-caves a relatively wide channel in
the middle of the bag 12 between the opposing gussets
(20a, 20b, 22a and 22b), again because the gussets do not
intrude as far into the bag as in a single gusset bag (See
FIG . 4 ) . This wide channel helps to improve the pop
volume because most of the kernels, as they pop, can move
straight up, without moving laterally to avoid the gussets
20 (20a and b and 22a and b). Moreover, if a kernel should
be trapped within a relatively shallow gusset, less
lateral - vc L i5 needed before it can return to the
susceptor 2 8 .
If a kernel should be carried upward]y away from
25 the susceptor 28 before it is popped, it is desirable that
the kernel move downwa]-dly again, onto the susceptor 28,
as soon as possible. The wider channel between the
gussets t20a and b and 22a and b) further facilitates this
downward movement and tends to reduce the time that the
30 kernel is away from the susceptor 28.
In the exemplary bag 12 there are two gussets on
each side. However, other multiple gusset constructions,
such as three gussets O]l each side, are also advantageous.
WO 92/22475 _ PCr/US92/04955
10 21113~8 ~
It shouid be noted that a bag with multiple gus6ets on
each side will always include at least one outwardly
pointed fold in each side panel 20 and 22. In contrast,
a single gusset bag has only inwardly pointed folds. Out-
wardly pointed folds not only cause the bag 12 to expand
more readily and with less resistance, but allow the side
panels 20 and 22 to bulge outwardly to a greater extent.
This configuration gives the bag 12 a more pillow-like
shape, shown in FIG. 5, the bag being widest at its
vertical and longitudinal center point between the front
and back panels 14 and 16 (See Fig. 6). As compared to a
single gusset bag, the multiple gusset bag 12 becomes more
rounded with a more convex bottom formed by the front
panel 14. Not only does a bag that expands in this manner
have a greater volume, but it is susceptible to more
rocking movement during cooking. This rocking movement
tends to return unpopped kernels to the susceptor 28, for
still more volume and fewer url~u~ed kernels.
The seams that close the top 30 and bottom 38 of
the bag 12 are formed when pressure is applied to heat
seal strips. Sometimes heat is also applied. Though
these two seams are similar, the seam at the bottom end 38
is able to withstand higher internal pressures and
temperatures than the seam at the top end 30. This causes
the top seam to open and vent 6team before any other seam
~ including the overlapping seam 18 running the length of
the back panel 16) as the ~L~s~ur~ and temperature inside
the bag 12 increases. The preferred manner in which steam
is vented is described in more detail in U. S . Patent No .
4,571,337.
Preferably, the kernels of the charge 10 are all
of approximately equal size so that substantially all
kernels will pop uniformly and within a limited time, the
popping time in a microwave oven being partially dependent
35 on kernel size. Since popping is attributable to the
..
W~92/2247~ PCI~/US92/W9~
2111328
moisture content of the kernels, it is also important that
there be sufficient moisture. The moisture content of the
kernels should be between 13 to 14 percent by weight (13.5
percent being optimal) and no less than 11.5 percent. Too
5 little moi5ture re5ult5 in small popped kernels the
density of which is too high for the fluffy texture
des ired .
The shortening in the charge 10 is a solid at
room t~ clLu-.2. Since no refrigeration ifi required for
10 any of the ingredients, the product can be described as
shelf -stable .
When the fold~d bag 12 is ready for use, it is
placed in a microwave oven 40 with its front panel 14
resting on the oven floor 42 (as shown in FIG. 1) 50 that
15 the susceptor 28 is positioned underneath the charge 10.
Microwave energy is absorbed by the corn kernels of the
charge 10. The moisture content of the kernels turns to
steam, which causes th,e kernels to explode or "pop",
releasing the steam inside the bag 12. As the number of
20 popped kernels increases during cooking, the pressure of
the steam released by the popped kernels and that of the
popped kernels 44 themselves in~;L~ases. This ~Les~u.c:
causes the empty end sections 32 and 34 on either side of
the charge 10 to unfold, thereby straightening the bag 12
25 and extending it horizontally, and causing the gussets
(20a and b and 22a and b) to open gradually, as shown in
FIGS . 3 and 5 . To permit f ree and unrestricted popping
action, thus minimizing the number Of ""1~ kernels,
the internal steam ~LeS2.UL~ must create sufficient
30 vertical space 46 above the charge 10 to allow the kernels
to move of f the susceptor 2 8 as they pop .
The popping action has the beneficial effect of
shaking the bag 12 as the exploding kernels impact the
walls of the bag. As the ~Yr~nrl;ng bag 12 assumes an
'~p,
,
2/22475 PCr/US92~'04955
12 2111328
increasingly spherical shape, the exterior surface of the
front panel lg (on ~hich the bag rests) becomes pro-
gressively DOre rounded, as shown in FIG. 6, thus facili-
- tating the rocking motion of the bag caused by the impact
5 of exploding kernels. The shaking of the bag 12 encou-
rages any rr--inin~J l~nrorrPd kernels that have moved off
the susceptor 28 to roll back onto the susceptor, located
at what becomes the lo~ point at the bottom of the bag.
An alternative bag 50 shown in FIGS 7 and 8, is
10 general similar to the bag 12 of FIGS. 1-6, being a tube-
style bag with a wedge-shaped bottom. The :i;ole difference
relates to the manner in which the two bags 12 and 50 are
folded prior to expansion.
The bag 50 i~ characterized ~y a reverse folded
15 gusset on each side. The back panel 51, which faces
upwardly when the bag 50 is placed in an oven in the
position shown in FIG. 7, is folded along fold lines 52
and 54 that are parallel to the longitudinal edges 56 and
58 of the bag and spaced inwardly from the edges by the
20 width of a gusset. Th~s the upper and lower sections 60
and 62 of the uyyt. . L gusset on each side are exposed
when the bag 50 has not yet ~Yr Inrlr~r~. Only a relatively
narrow center area 64 of the back panel 51 is exposed
between the upper gusset sections 60.
It should be noted that a strip 66, 68 the width
of two gussets extendi~g along each edge 56, 58 of the bag
50 (on either side of the exposed center area 64 of the
back panel 51) has a thickness of four 3ayers of the paper
of which the bag is made. Two ~old lines 70 and 72
extend alon ~he centers of these strips 66 and 68, over-
lying the fold lines 52 and 54 of the back panel 51. The
,, inin~ portion of the bag, having a thickness of only
two layers, is relatively narrow. (As best shown in FIG.
8. ) No portion of the bag 50 has a thickness of more than
~'
. ~
W0 92/22475 13 21113 2 8 PCT/US92/04955
f our layer8 .
Two exposed fold lines 70 and 72 extend along the
centers of the strips 66 and 68, overlying the fold lines 52
and 54 of the back panel 16, which likewise extend along the
centers of the strips. The exposed fold lines 70 and 72 are
two of the fold lines 24 mentioned above that outline the
sections of the gussets 20a and b and 22a and b. When the
bag 12 assumes lts expanded configuration (FIG. 6), these
fold lines 70 and 72 become oblique creases where the side
panels 20 and 22 meet the back panel 16.
The construction of the reverse folded gussets
can best be seen by reference to FIGS. 3, 8 and 12, which
illustrate bag 12 in collapsed and partially collapsed
configurations. The bag is made of front panel 14, oppo8ing
back panel 16 and two side panels 20 and 22 connecting the
f ront and back panels .
The back panel has a pair of spaced apart
longitudinal fold lines 56 delineating an edge between the
back panel and each side panel. The front panel also has a
pair of spaced apart longitudinal fold lines 58 delineating
an edge between the front panel and each side panel.
As best seen in FIG. 12, each side panel has
three 1~ te, spaced apart, longitudinal fold lines,
70, 72, 74, which along with adjacent back and front edges,
56 and 58, respectively, delineate four longitudinal
generally rectangular gusset sections, 60, 61, 62 and 63.
Gusset sections 60 and 62, the gusset sections ad~acent the
back edge, form a back gusset, while gusset sections 61 and
63, the gusset sections ad~acent the front edge, form a
front gusset. The back panel additionally has a pair of
spaced apart longitudinal reverse fold lines 52. When the
bag is in its collapsed configuration, the back gusset is
reverse folded, so that the portions of the back panel
located between adjacent reverse fold lines and back edges
W0 92/22475 L3a 21113 2 8 ~CT/US92/04955
are pivoted around the reverse fold lines and the portions
are positioned substantially adjacent to the r. f nfl~r of
the back panel. When the bag is aonstructed of single ply
paper, this reverse folding results in a bag that, when it
is in its collapsed configuration, has a thickness of only
four layers in the areas c~n~=;n;ng gusset sections 60, 61,
62 and 63 and only two layers in the center portion 64
separating the reverse folded gusset sections 60.
If the reverse folded bag 50 is compared with the
multiple gussetted bag 12 that is not reverse folded, it can
be seen that the non-reverse folded bag has a maximum
thickrLess of six layers (along the edges) and a much larger
area in which there are or,ly two layers (see FIG. 4) .
Because of this difference, a stack o the non-reverse
folded bags 12 will be 50 percent higher than a stack of the
same number of reverse folded bags 50. Accordingly, the
reverse folded bags 50 are advantageous from a h;lnfll ;n~,
shipping and storage viewpoint.
Moreover, a ~tack of reverse folded bags 50,
having a wider area of Lnaximum thickness along the edges and
a narrower '~void" area of minimum thickness at the center,
is relatively stable as compared to a stack of multiple
gusset bags 12 that are not reverse folded and have a larger
"void". The reverse folded bags 50 are therefore more
easily handled, as in a f illing process .
When ~nflf~fl, the reverse folded bag 50 takes on
the same shape and appaearance as the non-reverse folded
multiple gusset bag 12, as shown in FIG. 5.
An alternative bag construction 150, shown in
WO g2/2247~ PCr/US92/04955
` ~ 14
211132g
FIG. 9, is 6imilar to 1:he bag 12 of FIGS. l through 6,
except that at the bottom end 152 the front and back
panels are folded to form a strip 158 of increased
thickness that extends across the bag transversely. Thus,
the bag 150 is of pinched bottom _o~ Lu~Lion and is not
a tube-style bag, althollgh it can be described as having
a wedge-shaped bottom. The gusset ends 160 at the top of
the bag lS0 are free to move inrlPrpn~pntly~ but at the
bottom 152 of the bag the gusset ends 162 are prevented
from ~oving ;n~PrPn~Pntly by the folded strip 58. For
this reason, the expansion of the bag 150 is more
restricted near the bottom end 152 and the bag will take
on a slightly more rounded shape near the top end 164 as
cooking proceeds. I~o~ever, the bag 150 does have
multiple gussets forme~ by its side panels 166 and
theref ore has many of the advantages of the bag 12 of
Figs. l through 6. It ~till expand more readily and with
less resistance and as compared to conventional single
gusset bags, and it will take on a more rounded shape,
extending outwardly at the sides beyond the periphery of
the front and back panels. Moreover, the back panel (not
shown) on which the bag ]50 rests during cooking will take
on a convex outer shape to facilitate rocking - v~
during popping, but not to the same extent as the bag 12
which has ;nAPron~lPntly movable gussets 23 at both end.
The back panel on which the bag 150 rests during cooking
will tend to have a flatter shape in the vicinity of the
strip 158.
An advantage of the bag 150 is that it can be
3 0 made on equipment designed f or pinched bottom bags and
still retain many of the advantages that arise from the
use of multiple gussets. It should also be noted that a
tube style bag without independently movable gusset ends
can be made without folding over the bottom end of the bag
to form the strip 158. Instead, the gusset ends 162 can
simply be bonded together by an adhesive, applied to their
~92/22475 PCr~USg2/04955
15 21113~8
opposing exterior surfaces near the bottom, providing a
bag having characteristics very similar to those of the
pinched bottom bag 150.
Still another er~o~; r ~ ~ L of the invention is a
flat bottom or stand-up bag 170, shown in FIGS. 10 and 11.
This bag 170 has the ,~dvantage that it is more conven-
iently used as a serving container as it can stand on its
flat bottom panel 172 once the corn it contains has been
fully popped. It should be noted that because of the
manner in which a flat bottom bag is conventionally
folded, the bottom panel 172 is formed of multiple layers
and is relatively riqid.
The flat bottom bag 170 has a larger volume in
relation to its length, making it more suitable for use in
smaller microwave ovens, particularly those of the
carousel type. The bag 170 includes multiple gussets 174
and 176, two on each side, as in the case of the bags
diccllcsPd above. This construction requires folding of
the bag 170 along fold lines, as best shown in FIG. 9.
The ~old lines of each side panel define a triangular
section 178 near the bottom panel 172, bordered by a lower
section 80 of the top gusset and an upper section 182 of
the bottom gusset. The fold lines also define a
trapezoidal section 184 bounded by an upper section 186 of
the top gusset, a lower section 188 of the bottom gusset
176, the triangular section 178 and the bottom panel 172.
It should be noted that the use of f lat bottom
construction precludes the formation of ind~rPn~l~ntly
movable gusset ends at the bottom of the bag 170. ~ore-
over, the front panel on which the bag 170 rests during
cooking (as shown in FIGS. 8 and 9) is precluded from
becnm;n~ as rounded as desired, particularly in the area
where it is adjacent to the more rigid bottom panel 172,
thus inhibiting rocking movement. However, the bag 170 of
'~'
..... . .. . . .,, ,, . .. , . , . ,,, ... ,, ... ~
9212247~ PCr~US92/0495~
W~l 16 2111328
FIGS. 8 ~nd 9 does have the advanl:age of ~eing more
readily ~YpAnAAhl ~ to promote increased popping and pro-
vides a wider interior channel in which the corn kernels
can expand and move upl~ardly between the gussets. q~he bag
5 170 may also take on a slightly more billowy shape when
- fully ~Yp;'n~o~ as coml~ared to a single gu~set flat bottom
bag. It will thus tend to have slightly increased
interior volume.
While particular forms of the invention have
10 been illustrated and described, it will be apparent that
various modif ications can be made without departing ~rom
the spirit and scope of the invention. Accordingly, it is
not intended thzt the invention be limited, except as by
the ~rp~nA~d claims.
