Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
VALVE AND VALVE STRIP FOR A RECLOSABLE CONTAINER
[0001] Blank
[0002] Blank
[0003] Blank
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0004] The present invention relates generally to a valve that may be used on
a container.
2. Description of the Background of the Invention
[0005] Food or other perishables are often stored in reclosable containers
such as
reclosable thermoplastic pouches. To keep food stored inside a pouch fresh for
an extended
period, a user may evacuate gas out of the pouch before completely sealing a
closure
mechanism of the pouch. Other reclosable pouches have been developed that have
a valve
that allows gas to be evacuated from the pouch after the closure mechanism has
already been
sealed.
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[0006] Some pouch valves have a patch of thermoplastic material covering an
aperture in
a pouch wall and sealed over a limited area of the pouch wall around a
periphery of the patch.
The patch has an aperture therethrough that is offset from the aperture in the
pouch wall.
Pressure from outside of the pouch forces the patch against the pouch wall
keeping the valve
closed. However, pressure from within the pouch forces the patch to separate
from the pouch
wall to allow air to flow through both apertures and out of the pouch. Another
valve has a
highly cohesive fluid in the space between the offset apertures to resist
separation of the
patch and the pouch wall. Still another valve has a porous layer of material
secured over the
aperture in the pouch wall, wherein the porous layer has a smaller area than
the patch.
[0007] Other valves have a cover flap disposed over an aperture in a pouch
wall, wherein
the cover flap lacks an aperture. The valves have an unsealed edge that
provides a path for
escaping air. One such valve has a separator layer disposed between an
adhesive layer
disposed on an inner surface of the cover flap and an aperture in the pouch
wall. The
separator layer is smaller than the cover flap, but larger than the aperture
and is shaped so that
the adhesive layer makes asymmetrical contact with the pouch wall around a
periphery of the
cover flap. Pressure from within the pouch forces a portion of the cover flap
having a smaller
adhesive contact area to separate from the pouch wall. The valve may also have
an
intermediate gas permeable layer between the separator layer and the aperture.
[0008] Another valve has a cover flap that is disposed across an entire width
of a pouch
wall. The flap overlays one or more apertures in the pouch wall to allow air
to escape from
within the pouch and prevent air from entering the pouch.
[0009] Yet another valve for a pouch has a patch that is disposed across an
entire width of
a pouch wall and is sealed to the pouch wall around a periphery of the patch.
A first plurality
of apertures extending through the pouch wall is offset from a second
plurality of apertures
extending through the patch. An adhesive is disposed between the first and
second pluralities
of apertures. Pressure from within the pouch overcomes the adhesive and forces
the patch to
separate from the pouch wall to allow air to escape from within the pouch.
[0010] A still further valve has a patch that is sealed around a periphery of
the valve over
an inner or outer surface of a plastic tube. The patch may be oriented axially
along a length
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of the tube, or circumferentially around the tube. The patch has a vent
opening that is offset
from a vent opening through the tube surface. A vent seal zone is defined
between the patch
and the tube surface. The tube is sealed on both ends such that pressure from
within the tube
forces the patch to separate from the tube surface to allow air to escape from
within the tube.
[0011] Yet another valve has first and second zipper flanges sealed to an
inside surface
of a pouch wall. A line of apertures is disposed through the pouch wall,
wherein the first
zipper flange is attached to the pouch wall on a first side of the apertures
and the second
zipper flange is attached to the pouch wall on a second opposite side of the
apertures. An air
path is formed between the first and second zipper flanges and the apertures.
Pressure from
within the pouch forces the second flange away from the first flange and
pressure from
outside the pouch forces the second flange into contact with the first flange.
Alternatively,
the second flange is eliminated and the pouch wall on the second side of the
line of apertures
makes contact with the first flange. In another variation, one or more
apertures disposed
through the first flange are covered in flap fashion by the second flange.
[0012] Multiple layers of film material may be joined together, for example,
by ultrasonic
vibration, heat sealing, an adhesive, or by other means as known to one
skilled in the art to
form gastight sealed regions between the multiple layers. In one instance,
multiple layers of
film are bonded together by an intermittent ultrasonic bond. The intermittent
bond has a
number of bond points spaced close together along a line to provide a leak-
proof seal
between the layers. Material displaced from each of the bond points may make
contact with
or may be close enough to material displaced from an adjacent bond point to
block passage of
fluid therebetween.
[0013] Sealed regions between multiple layers of film material may be formed
by
application of an adhesive between the layers. Adhesives generally provide an
enduring
gastight seal, but environmental conditions may cause the gastight seal to
degrade. For
example, an adhesive may suffer from loss of tact in cold conditions, or may
become
excessively fluid in hot or microwaved conditions, resulting in flow of the
adhesive into areas
of the container where the adhesive may not be intended to go, such as into
contact with food.
A thermal seal may be more resistant than an adhesive seal to degradation
caused by
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environmental conditions. A thermal seal between multiple layers of film
material may be
created by application of energy in the form of heat and/or ultrasonic
vibration to a target
sealing region. The applied energy may cause material within the target region
to become
molten and to thereby bond the layers in a gastight seal. However, the molten
material may
flow away from the target region, and cause expansion and/or shrinkage of the
film material
surrounding the target region, which may form wrinkles in one or more layers
of the film
material outside of the target region.
SUMMARY OF THE INVENTION
[0014] According to one aspect of the invention, a reclosable pouch having a
valve
comprises first and second opposing sidewalls and complementary interlocking
closure
elements disposed on the respective first and second opposing sidewalls.
Opposing first and
second film layers are disposed over the first sidewall. The first film layer
is attached to the
second film layer by a first intermittent spot seal disposed at least across a
first edge of the
first film layer and a second intermittent spot seal disposed at least across
a second edge of
the first film layer. The second film layer is sealed to the first sidewall by
a third intermittent
spot seal disposed across at least across a third edge of the second film
layer and a fourth
intermittent spot seal disposed at least across a fourth edge of the second
film layer.
Opposing surfaces of the first and second film layers form a substantially
gastight seal
therebetween upon contact of the film layers. Offset first and second
apertures extend
through the first and second film layers, respectively, one of the first and
second apertures is
in fluid communication with an interior of the pouch and the other of the
first and second
apertures is in fluid communication with an exterior of the pouch. A fifth
intermittent spot
seal connects the first and second film layers, the fifth intermittent spot
seal surrounding a
region defined by the first and second apertures.
[0015] According to another aspect of the invention, a reclosable pouch having
a valve
comprises first and second opposing sidewalls. Opposing first and second film
layers are
disposed on the first sidewall. The first film layer is attached to the second
film layer by a
first intermittent spot seal disposed at least across a first edge of the
first film layer and a
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second intermittent spot seal disposed at least across a second edge of the
first film layer.
The second film layer is sealed to the first sidewall by a third intermittent
spot seal disposed
across at least across a third edge of the second film layer and a fourth
intermittent spot seal
disposed at least across a fourth edge of the second film layer. Opposing
surfaces of the first
and second film layers form a substantially gastight seal therebetween upon
contact of the
film layers. Offset first and second apertures extend through the first and
second film layers,
respectively, one of the first and second apertures is in fluid communication
with an interior
of the pouch and the other of the first and second apertures is in fluid
communication with an
exterior of the pouch. The first film layer is configured to separate from the
second film layer
to allow gas to exhaust from the pouch when a vacuum pressure is disposed over
the one of
the first and second apertures in fluid communication with the exterior of the
pouch.
[0016] According to yet another aspect of the invention, a gastight valve
strip comprises
opposing first and second film layers adapted to be disposed over a first
aperture through a
sidewall of a container. The first film layer is attached to the second film
layer by a first
thermal seal disposed around the periphery of the first film layer. An
attachment surface of
the second film layer is adapted to be sealed to the sidewall of the
container, and opposing
surfaces of the first and second film layers form a substantially gastight
seal therebetween
upon contact of the film layers. Offset second and third apertures extend
through the first and
second film layers, respectively, the second aperture is in fluid
communication with an
exterior side of the valve strip and the third aperture is configured to be in
fluid
communication with the first aperture, wherein the second aperture is spaced
from the third
aperture. A second thermal seal is disposed between the first and second
layers, the second
thermal seal comprising an intermittent spot seal and surrounding a region
including the
second and third apertures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an isometric view of a reclosable pouch incorporating a valve
and
illustrating valve layers peeled up for clarity;
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[0018] FIG. IA is an isometric view of a reclosable pouch illustrating a
textured pattern
on a sidewall;
[0019] FIG. 2 is a fragmentary cross-sectional view of an embodiment of a
valve taken
generally along the lines 2-2 of FIG. IA with portions behind the plane of the
cross-section
omitted for clarity;
[0020] FIG. 3 is a fragmentary cross-sectional view taken generally along the
lines 3-3 of
FIG. IA with portions behind the plane of the cross-section omitted for
clarity;
[00211 FIG. 4 is a fragmentary cross-sectional view taken generally along the
lines 3-3 of
FIG. IA with first and second layers of the valve of the first embodiment
separated and with
portions behind the plane of the cross-section omitted for clarity;
[0022] FIG. 4A is a fragmentary cross-sectional view of another embodiment of
a valve
taken generally along the lines 3-3 of FIG. IA with portions behind the plane
of the cross-
section omitted for clarity;
[0023] FIG. 4B is a fragmentary cross-sectional view of a further embodiment
of a valve
taken generally along the lines 3-3 of FIG. 1A with portions behind the plane
of the cross-
section omitted for clarity;
[0024] FIG. 4C is a fragmentary cross-sectional view of the valve of FIG. 3
illustrating
embossing on an interior surface of a pouch sidewall with portions behind the
plane of the
cross-section omitted for clarity;
[0025] FIG. 5 is a fragmentary cross-sectional view of another embodiment of a
valve
taken generally along the lines 3-3 of FIG. 1A with first and second layers
thereof separated
and with portions behind the plane of the cross-section omitted for clarity;
[0026] FIG. 6 is a fragmentary plan view of a first sidewall of a pouch
illustrating a
further embodiment of a valve;
[0027] FIG. 6A is a plan view of a first sidewall of a pouch illustrating a
still further
embodiment of a valve;
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[0028] FIG. 6B is a fragmentary plan view of a first sidewall of a pouch
illustrating
another embodiment of intermittent spot seals;
[0029] FIG. 6C is a cross-sectional view of one possible embodiment of the
intermittent
spot seal of FIG. 6B taken generally along the lines 6C-6C of FIG. 6B;
[0030] FIG. 6D is a cross-sectional view of another possible embodiment of the
intermittent spot seal of FIG. 6B taken generally along the lines 6D-6D of
FIG. 613;
[0031] FIG. 6E is a close-up view of an intermittent spot seal that comprises
individual
circular spots;
[0032] FIG. 6F is a close-up view of an intermittent spot seal that comprises
individual
triangular spots;
[0033] FIG. 6G is a fragmentary plan view of an embodiment of a valve;
[0034] FIG. 6H is a fragmentary plan view of another embodiment of a valve
[0035] FIG. 7 is a fragmentary cross-sectional view taken generally along the
lines 7-7 of
FIG. 6 with portions behind the plane of the cross-section omitted for
clarity;
[0036] FIG. 8 is a fragmentary cross-sectional view taken generally along the
lines 2-2 of
FIG. IA and illustrating yet another embodiment of a valve with portions
behind the plane of
the cross-section omitted for clarity;
[0037] FIG. 8A is a fragmentary cross-sectional view taken generally along the
lines 8A-
8A of FIG. 6A and illustrating another embodiment of a valve with portions
behind the plane
of the cross-section omitted for clarity;
[0038] FIG. 9 is a fragmentary cross-sectional view taken generally along the
lines 2-2 of
FIG. IA and illustrating a still further embodiment of a valve with portions
behind the plane
of the cross-section omitted for clarity;
[0039] FIG. 9A is a fragmentary cross-sectional view taken generally along the
lines 9A-
9A of FIG. 6A and illustrating another embodiment of a valve with portions
behind the plane
of the cross-section omitted for clarity;
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[0040] FIG. 10 is an isometric view of the reclosable pouch illustrating still
another
embodiment of a valve with valve layers peeled up for clarity;
[0041] FIG. I 1 is a an isometric view of the reclosable pouch illustrating a
yet further
embodiment of a valve with valve layers peeled up for clarity;
[0042] FIG. 12 is a fragmentary cross-sectional view taken generally along the
lines 12-
12 of FIG. 11 with portions behind the plane of the cross-section omitted for
clarity;
[0043] FIG. 13 is a partial cross-sectional view depicting layers and plies
for a valve and
taken generally along the lines 3-3 of FIG. IA, with portions behind the plane
of the cross-
section omitted for clarity;
[0044] FIGS. 14 and 15 are partial cross-sectional views similar to that of
FIG. 13
illustrating alternative constructions of layers and plies for valves herein;
[0045] FIG. 16 is an isometric view of another embodiment of a valve on a
container;
[0046] FIG. 17A is a cross-sectional view taken generally along the lines 17-
17 of
FIG. 16, with portions behind the plane of the cross-section omitted for
clarity;
[0047] FIG. 17B is a cross-sectional view taken generally along the lines 17-
17 of
FIG. 16 and illustrating yet another embodiment of a valve, with portions
behind the plane of
the cross-section omitted for clarity;
[0048] FIG. 18 is an isometric view of a still further embodiment of a valve
on a
container; and
[0049] FIG. 19 is a fragmentary cross-sectional view taken generally along the
lines 19-
19 of FIG. 18, with portions behind the plane of the cross-section omitted for
clarity;
[0050] FIG. 20 is a plan view of an embodiment of an independently constructed
valve
applied to a container;
[0051] FIG. 21 is a cross-sectional view taken generally along the lines 21-21
of FIG. 20;
[0052] FIG. 22 is a plan view of another embodiment of an independently
constructed
valve applied to a container; and
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[0053] FIG. 23 is a cross-sectional view taken generally along the lines 23-23
of FIG. 22.
[0054] Other aspects and advantages of the present invention will become
apparent upon
consideration of the following detailed description, wherein similar
structures have similar
reference numerals.
DETAILED DESCRIPTION
[0055] While the present invention may be embodied in many forms, several
embodiments are discussed herein with the understanding that embodiments
illustrated are to
be considered only as an exemplification of the invention and are not intended
to limit the
disclosure to the embodiments illustrated. For example, while a reclosable
pouch and a
reclosable hard-walled container are shown, any other container, such as
reclosable or non-
reclosable, soft- or hard-walled, to which a valve can be applied to evacuate
gas therefrom
can also be used with the present invention.
[0056] Turning now to the figures, a reclosable thermoplastic pouch 50,
illustrated in
FIG. 1, includes a first sidewall 52, a second sidewall 54, and a valve 40.
The first and
second sidewalls 52 and 54 are joined around three side edges 56a-56c by heat
sealing,
adhesive, ultrasonic vibration, or other sealing method known in the art to
define an opening
56 leading to an interior 58. Alternatively, bottom side edge 56b may be a
fold line between
the first and second sidewalls 52 and 54. A closure mechanism 60 extends
across a full width
62 of the pouch 50 proximate the opening 56. The closure mechanism 60 allows
the pouch
50 to be repeatedly opened and closed. When occluded, the closure mechanism 60
preferably
provides a gastight seal such that a vacuum may be maintained in the pouch
interior 58 for a
desired period of time, such as days, months, or years, when the closure
mechanism is sealed
fully across the opening 56.
[0057] The closure mechanism 60 comprises first and second complementary
interlocking closure elements 200, 202 (illustratively shown in FIG. 12) that
are disposed
along the respective inner surfaces 152 and 154 of the first and second
sidewalls 52 and 54.
The first interlocking closure element 200 includes one or more interlocking
closure profiles
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200a (illustratively shown in FIG. 12), and the second interlocking closure
element 202 also
includes one or more interlocking closure profiles 202a (illustratively shown
in FIG. 12).
The first and second interlocking closure profiles 200a, 202a may be male and
female closure
profiles, respectively, as shown. However, the configuration and geometry of
the
interlocking profiles 200a, 202a or closure elements 200, 202 disclosed herein
may vary.
[0058] In a further embodiment, one or both of the first and second
complementary
interlocking closure elements 200, 202 may include one or more textured
portions, such as a
bump or crosswise groove in one or more of the first and second closure
profiles 200a, 202a
in order to provide a tactile sensation, such as a series of clicks, as a user
draws the fingers
along the closure mechanism 60 to seal the closure elements across the
opening. In another
embodiment, the first and second interlocking closure profiles 200a, 202a
include textured
portions along the length of each profile to provide tactile and/or audible
sensations when
closing the closure mechanism 60. In addition, protuberances, for example
ridges (not
shown), may be disposed on the inner surfaces 152, 154 of the respective first
and second
sidewalls 52, 54 proximate the opening 56 to provide increased traction in a
convenient area
for a user to grip, such as a gripping flange, when trying to open the sealed
pouch 50.
[0059] Further, in some embodiments, a sealing material such as a polyolefin
material or
a caulking composition such as silicone grease may be disposed on or in the
interlocking
profiles 200a, 202a or closure elements 200, 202 to fill in any gaps or spaces
therein when
occluded. The ends of the interlocking profiles 200a, 202a or closure elements
200, 202 may
also be welded or sealed to provide an end-stomp seal between the first and
second closure
elements 200, 202 by, for example, crushing, ultrasonic vibration, and/or
application of heat
as is known in the art. Illustrative interlocking profiles, closure elements,
sealing materials,
tactile or audible closure elements, and/or end-stomps useful in the present
invention include
those disclosed in, for example, Pawloski U.S. Patent No. 4,927,474, Dais et
al. U.S. Patent
Nos. 5,070,584, 5,478,228, and 6,021,557, Tomic et al. U.S. Patent No.
5,655,273, Sprehe
U.S. Patent No. 6,954,969, Kasai et al. U.S. Patent No. 5,689,866, Ausnit U.S.
Patent No.
6,185,796, Wright et al. U.S. Patent No. 7,041,249, Pawloski et al. U.S.
Patent No.
7,137,736, Tilman et al. U.S. Patent No. 7,290,660, Anderson U.S. Patent
Application
Publication No. 2004/009 1 1 79, Pawloski U.S. Patent Application Publication
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No. 2004/0234172, and Anzini et at U.S. Patent Application Publication Nos.
2006/0093242
and 2006/0111226. It is further appreciated that the interlocking profiles or
closure elements
disclosed herein may be operated by hand, or a slider (not shown) may be used
to assist in
occluding and de-occluding the interlocking profiles and closure elements.
[0060] The resealable pouch described herein can be made by various techniques
known
to those skilled in the art including those described in, for example, Geiger,
et al., U.S. Patent
No. 4,755, 248. Other useful techniques to make a resealable pouch include
those described
in, for example, Zieke et al., U. S. Patent No. 4,741,789. Additional
techniques to make a
resealable pouch include those described in, for example, Porchia et al., U.
S. Patent No.
5,012,561. Additional examples of making a resealable pouch as described
herein include,
for example, a cast post applied process, a cast integral process, and/or a
blown process.
[0061) A first layer 64 of a film material may be disposed on the first
sidewall 52. A
second layer 66 of film material may also be disposed on the first sidewall 52
between the
first sidewall and the first layer 64. Each of the first and second layers 64,
66 may be
disposed on a portion of the first sidewall 52, or across the full width 62 of
the first sidewall
52, as illustrated in FIG. 1. Further, each of the first and second layers 64
and 66 may be
comprised of one or more plies of material. An exterior 68 of the pouch 50 is
also shown in
FIG. 1.
[0062] Referring next to an embodiment of the valve 40 as seen in FIG. 2, the
second
layer 66 has an overlap region 70 that overlaps the first sidewall 52. The
overlap region 70
comprises the entire second layer 66. A projection 72 of the overlap region 70
of the second
layer 66 is shown by the area outlined by the dashed lines in FIG. 1.
[0063] Referring now to FIGS. 1 and 2, a first aperture 74 extends through the
first layer
64 and a second aperture 76 extends through the second layer 66. The first
layer 64 is
attached to the second layer 66 at a portion of the second layer.
Illustratively, the first layer
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64 is attached to the second layer 66 around the entire periphery of the
second layer, or along
one or more peripheral edges 94, 98, 194, 198 of the second layer. The first
and second
layers 64 and 66 are attached to each other by a thermal seal 78a along the
peripheral edge 94
and by a thermal seal 78b along the peripheral edge 98. The thermal seals 78a,
78b may be
continuous as shown in FIG. 6, or may be intermittent spot seals 178a, 178b as
shown in FIG.
6A. Each of the thermal seals 78a, 78b, 178a, 178b may be a heat seal, a seal
created by
ultrasonic vibration, or some other thermal seal as is known in the art.
[0064] The second layer 66 is sealed to the first sidewall 52 at a periphery
of the overlap
region 70 of the second layer 66, including for example, around a periphery of
the overlap
region or on at least a portion of the overlap region. In the embodiment of
FIG. 2, a
thermoplastic weld layer 80 is disposed coextensively with the second layer 66
between the
sidewall 52 and the second layer 66 to seal the entire second layer 66 to the
first sidewall 52.
The thermoplastic weld layer 80 may be composed of any suitable thermoplastic
material,
such as for example, polypropylene-
[0065] A third aperture 82 extends through the thermoplastic weld layer 80 and
a fourth
aperture 84 extends through the first sidewall 52, as illustrated in FIG. 2.
The second, third,
and fourth apertures, 76, 82, and 84 are arranged to be coincident along a
line perpendicular
to the sidewall 52, to allow fluid communication of the second aperture 76
with the interior
58 of the pouch 50. The first aperture 74 in the first layer 64 is in fluid
communication with
the exterior 68 of the pouch 50.
[0066] One or both sidewalls, such as the second sidewall 54, may also be
embossed or
otherwise textured with a pattern 254, as illustrated in FIGS. 1A and 4C. One
or both
surfaces of the second sidewall 54, for example the inner surface 154, may be
embossed or
textured between the bottom side edge 56b and the closure mechanism 60, or a
separate
textured or embossed patterned wall may be used to provide flow channels (not
shown)
within the pouch interior 58. In one embodiment, the second sidewall 54 is
embossed with a
diamond pattern 254, for example, as shown in FIGS. lA and 4C, wherein the
pattern extends
from just beneath the closure mechanism 60 to the bottom side edge 56b and
opposes the
second aperture 76 that is in fluid communication with the interior 58 of the
pouch 50. The
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flow channels may provide fluid communication between the pouch interior 58
and the valve
40 when gas is being drawn through the valve 40. Illustrative flow channels
useful in the
present invention include those disclosed in Zimmerman et al. U.S. Patent
application
publication No. 2005/0286808 and Tilman et al. U.S. Patent No. 7,290,660-
[00671 Referring next to FIG. 3, the first aperture 74 is offset from the
second, third, and
fourth apertures 76, 82, and 84. The first and second layers 64 and 66 are in
direct contact in
an intermediate seal region 86 between the offset first and second apertures
74 and 76.
Although the first and second apertures 74 and 76 are shown in FIG. 3 to be
offset from one
another along the width 62 of the pouch 50, in all of the embodiments
described herein the
first and second apertures may be offset in any relative orientation that
allows for direct
contact of the first and second layers 64 and 66 in the intermediate seal
region 86 between the
first and second apertures. A substantially gastight seal is formed between
the first and
second layers 64 and 66 by direct contact of the first layer to the second
layer.
[0068] In one embodiment, the first and second sidewalls 52, 54 and/or the
closure
mechanism 60 are formed from thermoplastic resins by known extrusion methods.
For
example, the sidewalls 52, 54 may be independently extruded of thermoplastic
material as a
single continuous or multi-ply web, and the closure mechanism 60 may be
extruded of the
same or different thermoplastic material(s) separately as continuous lengths
or strands.
Illustrative thermoplastic materials include polypropylene (PP), polyethylene
(PE),
metallocene-polyethylene (mPE), low density polyethylene (LDPE), linear low
density
polyethylene (LLDPE), ultra low density polyethylene (ULDPE), biaxially-
oriented
polyethylene terephthalate (BPET), high density polyethylene (HOPE),
polyethylene
terephthalate (PET), among other polyolefin plastomers and combinations and
blends thereof.
Further, the inner surfaces 152, 154 of the respective sidewalls 52, 54 or a
portion or area
thereof may, for example, be composed of a polyolefin plastomer such as an
AFFINITYTM
resin manufactured by Dow Plastics. Such portions or areas include, for
example, the area of
one or both of the sidewalls 52, 54 proximate and parallel to the closure
mechanism 60 to
provide an additional cohesive seal between the sidewalls 52, 54 when the
pouch 50 is
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evacuated. One or more of the sidewalls 52, 54 in other embodiments may also
be formed of
air-impermeable film. An example of an air-impermeable film includes a film
having one or
more barrier layers, such as an ethylene-vinyl alcohol copolymer (EVOH) ply or
a nylon ply,
disposed between or on one or more of the plies of the sidewalls 52, 54. The
barrier layer
may be, for example, adhesively secured between the PP and/or LDPE plies to
provide a
multilayer film. Other additives such as colorants, slip agents, and
antioxidants, including for
example talc, oleamide or hydroxyl hydrocinnamate may also be added as
desired. In another
embodiment, the closure mechanism 60 may be extruded primarily of molten PE
with various
amounts of slip component, colorant, and/or talc additives in a separate
process. The fully
formed closure mechanism 60 may be attached to the pouch body using a strip of
molten
thermoplastic weld material, or by an adhesive known by those skilled in the
art, for example.
Other thermoplastic resins and air-impermeable films useful in the present
invention include
those disclosed in, for example, Tilman et al. U.S. Patent No. 7,290,660.
[0069] With reference to FIG. 4, and not wishing to be bound by theory, the
operation of
the embodiment of FIGS. 2 and 3 will now be described, it being believed that
the other
embodiments discussed herein operate in a similar fashion. Gas pressure from
the exterior 68
of the pouch 50 that is greater than or equal to a gas pressure of the
interior 58 of the pouch
compresses the pouch and forces the first and second layers 64 and 66 into
contact with each
other, thereby forming a substantially gastight seal. Further, an opening
region 88 of the first
layer 64 disposed directly over the second aperture 76, is subject to any
pressure imbalance
between the interior and exterior 58 and 68 of the pouch 50. Increased gas
pressure from the
interior 58 of the pouch 50 forces the opening region 88 of the first layer 64
away from the
second layer 66 and thereafter a remainder of the first layer is forced away
from the second
layer. Separation of the opening region 88 from the second aperture 76 allows
higher
pressure gas from within the interior 58 of the pouch 50 to spread away from
the second
aperture into a space 158 formed between the layers 64 and 66. An expanding
zone of higher
pressure gas applies a pressure imbalance to a corresponding expanding region
of the first
layer 64. When the expanding zone of higher pressure gas reaches the first
aperture 74, the
higher pressure gas escapes through the first aperture to the exterior 68 of
the pouch 50. At
CA 02696251 2011-10-20
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this point, gas can escape freely from the interior 58 of the pouch 50 to the
exterior 68 of the
pouch following a path 90 as depicted by the curved line and arrow in FIG. 4-
[0070) The valve 40 provides a fluid path with direct fluid communication
between the
interior 58 and the exterior 68 of the pouch 50. Although not shown, in some
embodiments a
second valve may be disposed in or through the closure mechanism 60 or in one
of the side
edges 56a-56c of the pouch. Illustrative second valves useful in the present
invention include
those disclosed in, for example, Newrones et at. U.S. Patent Application
Publication No.
2006/0228057.
[0071] In use, application of vacuum pressure over the exterior of the first
and second
apertures 74 and 76 causes the interior 58 of the pouch 50 below the first and
second
apertures to have a greater pressure than the exterior. Vacuum pressure may be
applied by an
evacuation pump or device or any other source of vacuum pressure known in the
art, for
example, by placing a vacuum cup of the evacuation pump in contact with an
outer surface of
the pouch and drawing a vacuum on an interior of the vacuum cup, thereby
creating an
expansive pressure imbalance and holding down the first and second layers 64
and 66 around
the pressure imbalance.
[0072] In another embodiment, as illustrated in FIG. 4A, a region on a surface
of the
second layer 66 that faces the first layer 64 and that is disposed between the
first and second
apertures 74, 76 and bounded by the second aperture 76 may also be embossed or
otherwise
textured with a pattern 65 to define a region of flow channels 67. In a
further embodiment, as
illustrated in FIG. 4B, a region on a surface of the first layer 64 that faces
the second layer 66
and that is disposed between the first and second apertures 74, 76 and at
least partially
overlapping the second aperture 76 may also be embossed or otherwise textured
with the
pattern 65 to define the region of flow channels 67. In these embodiments, the
first and
second layers 64 and 66 are in direct contact in an intermediate seal region
87 between the
CA 02696251 2010-03-10
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first aperture 74 and the region of flow channels 67, which is in fluid
communication with the
interior 58 of the pouch 50. In use, application of vacuum pressure over the
exterior of the
first aperture 74 and a portion of the region of flow channels 67 causes gas
resident within the
region of flow channels 67 to have a greater pressure than the exterior.
[0073] It is further contemplated that the pouch 50 may include a one-way
valve disposed
on at least one of the first and second pouch sidewalls and flow channels
disposed on at least
one of the first and second pouch sidewalls and in fluid communication with
the one-way
valve, and may be provided as a component of a kit or package that comprises a
vacuum
pump to evacuate gas from the interior of the pouch through the one-way valve.
[0074] Although not shown, a porous or adhesive layer disposed between one or
more of
the valve layers 64, 66 may also be desired in any of the embodiments
disclosed herein.
Examples of adhesives useful in the present invention include those described
in, for
example, Hamilton U.S. Patent No. 7,004,632 or Mizuno U.S. Patent No.
5,989,608.
Examples of a porous material useful in the present invention include those
described in, for
example, Mizuno U.S. Patent No. 5,989,608 or Shah et al. U.S. Patent
Application
Publication No. 2004/0223667.
[0075] In the creation of a thermal seal between two or more layers of
thermoplastic
material, energy and/or pressure may be applied to a target sealing region to
at least partially
melt one or more of the layers such that melted portions between any two
layers create a
bond therebetween. A consequence of applying energy and/or pressure to melt
the material
in the target region may be that the melted material flows away from the
target region. This
flow of material away from the target region may form wrinkles in one or more
of the layers.
Such wrinkles may be aesthetically or otherwise undesirable, for example, such
wrinkles may
inhibit or prevent formation of a gastight seal between the wrinkled layers.
However, the
creation of wrinkles may be alleviated by several techniques. For example, in
the creation of
a heat seal, heat may be applied to an entire layer (or layers) to pre-heat
the material prior to
creating the heat seal. Further, heat may be applied to multiple layers of
material from both a
top side and a bottom side to alleviate uneven material expansion due to
temperature
gradients through the material. In the creation of a seal by ultrasonic
vibration, a vibrating
CA 02696251 2010-03-10
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surface may be forced against the layers of material to melt the layers and
create a bond
therebetween. Wrinkling may be alleviated in a desired region of the material
by angling the
vibrating surface away from the desired region to push the melted material
away therefrom.
[0076] Wrinkling may also be alleviated by the use of intermittent spot seals
to create a
seal region. For example, referring to FIGS. 6B-6D, the second layer 66 may be
sealed to the
first sidewall 52 by an intermittent spot seal 278a along the peripheral edge
94 and by an
intermittent spot seal 278b along the peripheral edge 98. In one embodiment
illustrated in
FIG. 6A, individual sealing spots of the intermittent spot seals 278a and 278b
may be
coincident with individual sealing spots of the respective intermittent spot
seals 178a and
178b. In another embodiment, as schematically illustrated in FIGS. 6B-6D, the
individual
sealing spots of the intermittent spot seal 178a are staggered with respect to
the individual
sealing spots of the intermittent spot seal 278a, and/or the individual
sealing spots of the
intermittent spot seal 178b are similarly staggered with respect to the
individual sealing spots
of the intermittent spot seal 278b.
[0077] Optional strips 80a, 80b of thermoplastic weld layer material may
extend along
the respective peripheral edges 94, 98, as illustrated by dashed lines in FIG.
6B. Each of the
optional strips may be sandwiched between the second layer 66 and the first
sidewall 52, as
illustrated in FIG. 6D. An edge seal 279 may seal the edges 56a and 56c.
[0078] Each of the individual sealing spots that comprise the intermittent
spot seals 178b
and 278b that are schematically illustrated in FIGS. 6C and 6D has a melt
region around at
least a portion thereof. For example, each of the individual sealing spots of
the intermittent
spot seal 278b may comprise molten material comprised of one or more of the
second layer,
66, the optional strip of thermoplastic weld layer material 80b, and the first
sidewall 52.
[0079] Illustratively referring to FIG. 6E, a generally curved intermittent
spot seal 280
between two or more layers of thermoplastic material includes generally
circular individual
sealing spots 282. Each of the circular individual sealing spots 282 may be
surrounded by a
generally symmetric melt region 284. If the circular individual sealing spots
282 are not
spaced sufficiently from one another, portions of the symmetric melt regions
284 of the
adjacent circular individual sealing spots 282 may overlap as shown by overlap
regions 286.
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Wrinkles 287 that are created in the thermoplastic material surrounding the
symmetric melt
regions 284 may be exacerbated by the overlap regions 286.
[0080] Referring to FIG. 6F, a portion of generally curved intermittent spot
seal 288
includes generally triangular individual sealing spots 290. Each of the
triangular individual
sealing spots 290 may be surrounded by a generally asymmetric melt region 291.
The
wrinkles 287 may be less likely to form in this example than in the example
described with
regard to FIG. 6E hereinabove because, for example, the triangular individual
sealing spots
290 are spaced sufficiently far apart such that non-overlap regions 292 remain
between the
asymmetric melt regions 291. Further, corner regions 291a of the asymmetric
melt regions
291 opposite the corners of the triangular individual sealing spots 290 are
generally thinner
than side regions 291 b of the asymmetric melt regions 291 opposite the sides
of the triangular
individual sealing spots 290. Therefore, the wrinkles 287 may be less likely
to form in
localized areas of the thermoplastic material opposite the corner regions 291
a than the side
regions 291 b.
[0081] In another embodiment depicted in FIG. 5, the first and second layers
64 and 66
and the thermoplastic weld layer 80 are disposed on the interior 58 of the
pouch 50. In this
embodiment, the opening region 88 of the second layer 66 is disposed directly
over the first
aperture 74 disposed in the first layer 64. In all of the embodiments
described herein, either
the first aperture 74 or the second aperture 76 may be in fluid communication
with the
exterior 68 of the pouch 50 or, for example, may be covered by an additional
layer (not
shown) to protect or hide the aperture 74 or 76. The aperture 74 or 76 that is
in fluid
communication with the exterior 68 of the pouch 50 may be a slit or tPhole or
opening of any
cross-section, for example, circular, square-shaped, triangular, rectangular,
pentagonal, or any
other suitable shape.
[0082] Referring next to FIGS. 6 and 7, in a further embodiment, the first and
second
layers 64 and 66, the thermoplastic weld layer 80, and the first sidewall 52
are further
attached together by a surrounding thermal seal 92. The surrounding thermal
seal 92 may be
a continuous seal as shown in FIG. 6, or may be an intermittent spot seal 192
as shown in
FIGS. 6A, 6G, and 6H. The surrounding thermal seal 92 may optionally be
disposed between
CA 02696251 2010-03-10
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only the first and second layers 64 and 66. Alternatively, the first and
second layers 64 and
66 and the surrounding thermal seal 92 may be disposed on the interior 58 of
pouch 50. The
surrounding thermal seal 92 surrounds the first aperture 74 and the second
aperture 76. The
surrounding thermal seal 92 may be a heat seal, a seal formed by ultrasonic
vibration, or a
thermal seal formed by any thermal sealing method known in the art. Although
shown as a
circular seal in FIGS. 6, 6A, 6G, and 6H, the surrounding thermal seal 92 may
have any
shape, for example, triangular, elliptical, square-shaped, pentagonal,
hexagonal, etc.
[0083] Although the individual sealing spots that comprise the intermittent
spot seals
178a, 178b, and 192 are shown in FIG. 6A to be generally circular, the
individual sealing
spots may be, for example, circular, elliptical, square-shaped, triangular,
rectangular,
pentagonal, hexagonal, or other shapes. Referring to FIGS. 6G and 6H, in some
embodiments, the intermittent spot seal 192 may have an odd plurality of
circular individual
sealing spots 400, for example, three, five, seven, nine, eleven, thirteen,
fifteen, seventeen, or
more, such that a substantially gastight seal can form between the layers
joined by the
intermittent spot seal 192. In some cases, an odd number of the individual
sealing spots 400
may inhibit the formation of a wrinkle (not shown) that spans the intermittent
spot seal 192
between pairs of the individual sealing spots 400 that are aligned with one of
the side edges
56a-56c of the pouch 50. The number, size, and spacing of the circular
individual sealing
spots 400 may each be predetermined to minimize formation of wrinkles (not
shown) within
a perimeter of the intermittent spot seal 192 that may interfere with the
formation of a
substantially gastight seal in the intermediate sealing region 86 between the
offset first and
second apertures 74 and 76. For example, the intermittent spot seal 192 may be
configured
such that the symmetric melt regions 284 surrounding the adjacent circular
individual sealing
spots 400 do not overlap.
[0084] In another embodiment, the intermittent spot seal 192 may be comprised
of an odd
plurality of triangular individual sealing spots 402, as illustrated in FIG.
6H. The number,
size, and spacing of the triangular individual sealing spots 402 may also each
be
predetermined to minimize formation of wrinkles (not shown) within a perimeter
of the
intermittent spot seal 192. For example, the intermittent spot seal 192 may be
configured
such that the asymmetric melt regions 291 surrounding the adjacent triangular
individual
CA 02696251 2010-03-10
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sealing spots 402 do not overlap, and further such that the corner regions 291
a of the of the
asymmetric melt regions 291 point toward a central portion within the
intermittent spot seal
192. Fig. 6H further illustrates that the intermittent spot seals 178a and
178b may be
comprised of individual sealing spots 404 that are a different shape than the
triangular
individual sealing spots 402, for example, rectangular as shown.
[0085] In yet another embodiment, as seen in FIG. 8, first edges 94a and 94 of
the first
and second layers 64 and 66, respectively, are attached to the first sidewall
52 by a first edge
thermoplastic weld layer 96, and second edges 98a and 98 of the first and
second layers 64
and 66, respectively, are attached to the first sidewall 52 by a second edge
thermoplastic weld
layer 100. Alternatively, as seen in FIG. 8A, the first edges 94a and 94 of
the first and
second layers 64 and 66, respectively, are attached to the first sidewall 52
by the intermittent
spot seal 178a, and the second edges 98a and 98 of the first and second layers
64 and 66,
respectively, are attached to the first sidewall 52 by the intermittent spot
seal 178b.
Illustratively, the first and second edge thermoplastic weld layers 96, 100
and the intermittent
spot seals 178a, 178b are disposed across the full width 62 (FIG. 1) of the
first sidewall 52.
The first and second layers 64 and 66 and the first and second edge
thermoplastic weld layers
96, 100 or the intermittent spot seals 178a, 178b may alternatively be
disposed across a
portion of the first sidewall 52, or on the interior 58 of the pouch 50.
[0086] A still further embodiment is depicted in FIG. 9, wherein the entire
second layer
66 is sealed directly to the first sidewall 52. The first edge 94a of the
first layer 64 is attached
to the first sidewall 52 by the first edge thermoplastic weld layer 96, and
the second edge 98a
of the first layer 64 is attached to the first sidewall 52 by the second edge
thermoplastic weld
layer 100. Alternatively, as depicted in FIG. 9A, the first edge 94a of the
first layer 64 is
attached to the first sidewall 52 by the intermittent spot seal 178a, and the
second edge 98a of
the first layer 64 is attached to the first sidewall 52 by the intermittent
spot seal 178b. The
first and second layers 64 and 66 and the first and second edge thermoplastic
weld layers 96,
100 or the intermittent spot seals 178a, 178b may alternatively be disposed on
the interior 58
of the pouch 50.
CA 02696251 2010-03-10
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[0087] Referring next to FIG. 10, in still another embodiment, a first
plurality of
apertures 102 extends through the first layer 64. A second plurality of
apertures 104 extends
through the second layer 66, wherein the second plurality of apertures 104 is
offset from the
first plurality of apertures 102. A third plurality of apertures 106 extends
through the first
sidewall 52 of the pouch 50. The second and third pluralities of apertures 104
and 106 are
arranged to be coincident along a line perpendicular to the first sidewall 52,
thereby allowing
fluid communication of the second plurality of apertures 104 with the interior
58 of the pouch
50. Alternatively, the first and second layers 64 and 66 may be disposed on
the interior 58 of
the pouch 50.
[0088] In a yet further embodiment, as seen in FIGS. 11 and 12, the second
layer 66
includes an overlap region 170 that overlaps the first sidewall 52 and a
portion 108 that does
not overlap with the first sidewall. The projection 172 of the overlap region
170 of the
second layer 66 is shown by the area outlined by the dashed line in FIG. 11.
An edge 294 of
the second layer 66 is joined to a closure flange 110 that may have a first
closure element 200
disposed thereon, leaving a gap 112 across the full width 62 of the pouch 50
between the first
sidewall 52 and the closure flange. A second closure element 202 may also be
disposed on
the second sidewall 54 opposing the first closure element 200. The closure
elements 200 and
202 may be any type of complementary interlocking closure elements known in
the art, as
previously described herein. The second plurality of apertures 104 is in fluid
communication
with the interior 58 of the pouch 50 through the gap 112. The gap 112 is
sealed along first
and second ends 114 and 116 between the first layer 64 and the second sidewall
54. The first
and second edge thermoplastic weld layers 96 and 100 extend partially under
the second layer
66 to attach the first and second layers 64 and 66 together and attach the
first and second
layers to the first sidewall 52 and the closure flange 110, respectively. In
place of the
thermoplastic weld layers 96, 100, the intermittent spot seals 178a, 178b may
attach the first
and second layers 64 and 66 together and attach the first and second layers to
the first
sidewall 52 and the closure flange 110, respectively. Alternatively, the first
and second layers
64 and 66 and the first and second edge thermoplastic weld layers 96, 100 or
the intermittent
spot seals 178a, 178b may be disposed on the interior 58 of the pouch 50.
CA 02696251 2010-03-10
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[0089] The first and second layers 64 and 66 of any of the valves 40 as
disclosed herein
may be independently composed of any thermoplastic material such as would be
used for the
first and second sidewalls 52 and 54 of the pouch 50 as described herein. Each
of the first
and second layers 64 and 66 may be composed of the same material as the other
layer or
could be independently composed of different material than the other layer. In
addition, each
of the first and second layers 64 and 66 may also have multiple plies, each
ply being
independently composed of any thermoplastic material such as would be used for
the first and
second sidewalls 52 and 54 of the pouch 50 as described herein, or a blend of
any
thermoplastic material such as would be used for the first and second
sidewalls of the pouch
as described herein. Illustratively, the first and second layers 64 and 66
may, for example, be
composed of a polyolefin plastomer such as an AFFINITYTM resin manufactured by
Dow
Plastics.
[0090] FIGS. 13-15 depict various illustrative embodiments for the first and
second
layers 64 and 66. Referring to FIG. 13, the first layer 64 is composed of a
first ply 118 and a
second ply 120. Although any suitable flexible thermoplastic materials may be
used for the
first and second plies 118 and 120, in this embodiment, for example, the first
ply 118 is
composed of polypropylene or HDPE and the second ply 120 is composed of a
polyolefin
plastomer. The second layer 66 in FIG. 13 includes a single ply and may be
made of any
suitable flexible thermoplastic, but illustratively the second layer 66 is
made of
polypropylene, HDPE, polyolefin plastomer, or a blend of any two or all three
of
polypropylene, HDPE, and polyolefin plastomer. The structures of the first and
second layers
64 and 66 may also be reversed such that the first layer 64 has a single ply
and the second
layer 66 has two plies. Other additives known to those skilled in the art may
also be included
in the composition of the first and second layers 64 and 66, as desired such
as to improve
handling and manufacturing characteristics.
[0091] As seen in FIG. 14, the first layer is substantially identical to that
of FIG. 13 and
the second layer 66 is composed of a first ply 122 and a second ply 124.
Although any
suitable flexible thermoplastic materials may be used for the first and second
plies 122 and
124 of the second layer 66, in this embodiment, for example, the first ply 122
is composed of
a polyolefin plastomer and the second ply 124 is composed of polypropylene or
HDPE.
CA 02696251 2010-03-10
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[0092] Referring next to FIG. 15, the first and second layers 64 and 66 are
both
composed of a single ply of material. Although any suitable flexible
thermoplastic materials
may be used for the first and second layers 64 and 66, illustrative materials
are polyolefin
plastomer, polypropylene, HDPE, or a blend of any two or all three of
polypropylene, HDPE,
and polyolefin plastomer.
[0093] Although not shown, it is also contemplated that one or more of the
valves 40 or
valve layers, for example, the first or second layers 64 or 66, may extend
along a portion of
the width 62 of the pouch 50. For example, one or more of the valve layers may
extend only
along a portion of the pouch 50 proximate one side edge of the pouch, or may
be disposed
away from the side edges of the pouch toward the center of the pouch, or may
be offset from
the center of the pouch. However, by extending the valve 40 across the entire
width 62 of the
pouch 50 it is contemplated that the complexity of manufacturing the valve
and/or pouch may
be reduced because the first and second layers 64 and 66 may be applied in a
continuous
process.
[0094] Referring next to FIGS. 16 and 17A, a container 300 having a container
lid 302
that includes a valve 340 and that sealingly fits on a hard-walled container
body 304 is
illustrated. A container useful herein includes those disclosed in, for
example, Zettle et al.
U.S. Patent No. 6,032,827 or Stanos et al. U.S. Patent No. 7,063,231. A
sealing layer 306
may be applied to an inner surface 308 of a peripheral rim 310 of the lid 302
to assist in
achieving a gastight seal therebetween. A second sealing layer 306a of the
same or a
different sealing material may also be applied to a surface 312 of a
peripheral lip 314 of the
container body 304. Any suitable sealing material known to those skilled in
the art may be
used including, for example, one or more polyolefin plastomers, including, for
example, an
AFFINITYTM resin manufactured by Dow Plastics. The container body 304 may have
rigid
sidewalls 316 to support a variety of contents 318, for example, fresh
vegetables or other
perishable foodstuffs and may be made of any suitable material known to those
skilled in the
art, including, for example, a thermoplastic resin.
[0095] In this embodiment, a first layer 364 is disposed over an opening 320
defined by
an inner annular flange 368 of the lid 302. A second layer 366 is also
disposed over the
CA 02696251 2010-03-10
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opening 320. A first aperture 374 extends through the second layer 366, and a
second
aperture 376 is offset from the first aperture 374 and extends through the
first layer 364.
Illustratively, a peripheral thermoplastic weld layer 396 extends partially
under the first layer
364 to weld the first and second layers 364 and 366 together and weld the
first and second
layers to the inwardly projecting annular flange 368. The annular flange 368
has an
extension 370 that further extends from the annular flange toward the opening
320. A third
aperture 378 extends through the peripheral thermoplastic weld layer 396, and
a fourth
aperture 380 extends through the flange extension 370. The second, third, and
fourth
apertures 376, 378, and 380 are aligned along a line perpendicular to the
flange extension 370
such that the second aperture 376 is in fluid communication with an interior
322 of the
container body 304 when the lid 302 is applied thereto.
[0096] Referring to FIG. 17B, another embodiment of the lid 302 is illustrated
having an
elastomeric film layer 324 that spans the opening 320 defined by the annular
flange 368 of
the lid 302. The film layer 324 is made of a flexible thermoplastic material,
for example,
polyolefin plastomer, polypropylene, HDPE, or a blend of any two or all three
of
polypropylene, HDPE, and polyolefin plastomer. The film layer 324 is attached
to the
annular flange and the flange extension 370 by any suitable method known in
the art, for
example, by ultrasonic or thermal welding, by application of an adhesive, or
by a
thermoplastic weld layer 396a.
[0097] This embodiment is similar to the embodiment discussed in regard to
FIG. 17A
except for the differences described in the following. The first layer 364 and
the second layer
366 are disposed only over the extent of the flange extension 370. A fifth
aperture 382
extends through the film layer 324 and is aligned with the second, third, and
fourth apertures
376, 378, and 380 along a line perpendicular to the flange extension 370 such
that the second
aperture 376 is in fluid communication with the interior 322 of the container
body 304 when
the lid 302 is applied thereto. The first and second layers 364 and 366 may be
applied to the
film layer 324 over the flange extension 370 by any suitable method known in
the art, for
example, by a surrounding seal 392 that surrounds the first and second
apertures 374 and 376.
The surrounding seal 392 may be a continuous seal or may be an intermittent
spot seal as
discussed previously for another embodiment herein regarding the surrounding
seal 92.
CA 02696251 2010-03-10
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[0098] Further, it is also contemplated that any of the valves described
herein, for
example, the valve 340, may be constructed independently of the container 300
and applied
to the container, such as to the pouch 50, the container lid 302, or the
container body 304,
after or during the manufacturing thereof. One such embodiment is illustrated
in FIGS. 18
and 19, wherein the valve 340 is applied to the container body 304 using an
adhesive layer
384. In this embodiment, the film layer 324 of the lid 302 spans the opening
320 and
includes no apertures therethrough. Although the adhesive layer 384 is shown
to attach the
valve 340 to the container body 304, either of the first and second layers 364
and 366 may be,
alternatively or in addition to, attached to the sidewall 316 by any suitable
method known in
the art, for example, directly by a thermoplastic weld layer 396b. The first
aperture 374
extends through the second layer 366 and is offset from the second aperture
376 that extends
through the first layer 364. The third aperture 378 extends through the
thermoplastic weld
layer 396b and a fourth aperture 380a extends through the sidewall 316. A
fifth aperture
382a extends through the adhesive layer 384. The second, third, fourth, and
fifth apertures
376, 378, 380a, and 382a are aligned along a line perpendicular to the
sidewall 316 such that
the second aperture 376 is in fluid communication with the interior 322 of the
container body
304.
[0099] Further, it is believed that the embodiments shown in FIGS. 16-19
operate in a
fashion similar to the valves 40 described above. Illustratively, after the
contents 318 are
placed into the container body 304 and the lid 302 is applied thereto, a
source of vacuum
pressure (not shown) is applied over the first and second apertures 374 and
376. The flange
extension 370 or the sidewall 316 provides a support surface for application
of the source of
vacuum pressure. As gas is removed from the container body 304, the flexible
material of the
first and second layers 364 and 366 or the film layer 324 are compressed into
the container
body by atmospheric pressure. The first and second layers 364 and 366 or the
film layer 324
cover and conform to the contents 318 as the gas is removed from the container
body 304.
The first and second layers 364 and 366 or the film layer 324 may be attached
to the
peripheral flange 368 by any suitable method known in the art, for example, by
ultrasonic or
thermal welding, or by application of an adhesive.
CA 02696251 2010-03-10
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[00100] Another embodiment of a valve that may be constructed independently of
the
container 300 as a valve strip 440 and applied to the container, such as to
the pouch 50, the
container lid 302, and/or the container body 304, after or during the
manufacturing thereof is
illustratively shown in FIGS. 20 and 21. A first layer 464 of a film material
is disposed over
a second layer 466 of film material. Each of the first and second layers 464
and 466 may be
comprised of one or more plies of material as described hereinabove with
regard to the first
and second layers 64, 66. The first and second layers 464 and 466 are attached
to each other,
for example, by a thermal seal 478 around the periphery 480 of the first layer
464. The
thermal seal 478 may be continuous (not shown), or may be an intermittent spot
seal
comprising individual sealing spots 482 of any convenient shape, preferably
triangular, as
illustrated in FIG. 20. The thermal seal 478 may be a heat seal, a seal
created by ultrasonic
vibration, or some other thermal seal as is known in the art.
[001011 A first aperture 474 extends through the first layer 464 and a second
aperture 476
extends through the second layer 466. A surrounding thermal seal 492 that
connects the first
and second layers 464 and 466 surrounds the first aperture 474 and the second
aperture 476.
The surrounding thermal seal 492 may be a heat seal, a seal formed by
ultrasonic vibration, or
a thermal seal formed by any thermal sealing method known in the art. Although
shown as
circular in FIG. 20, the surrounding thermal seal 492 may any shape, for
example, triangular,
elliptical, square-shaped, pentagonal, hexagonal, etc. Also, the surrounding
thermal seal 492
may be continuous (not shown), or may be an intermittent spot seal comprising
individual
sealing spots 496 of any convenient shape, preferably triangular, as
illustrated in FIG. 20.
Further, the surrounding thermal seal 492 may be comprised of any number of
individual
sealing spots 496, for example, fifteen, as illustrated in FIG. 20. The
number, size, shape,
and spacing of the individual sealing spots 496 may also each be selected to
minimize
formation of wrinkles (not shown) within a perimeter of the surrounding
thermal seal 492, for
example, as described hereinabove.
[00102] A third aperture 484 extends through an exterior wall of the container
300, such as
the first sidewall 52, the lid 302, or the container sidewall 316. The second
layer 466 has an
attachment surface 468 that is adapted to be attached facing the third
aperture 484. At least a
portion of the attachment surface 468 may also be embossed or otherwise
textured with a
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pattern 486 to define a region of flow channels 488. The valve strip 440 may
have a means
for attachment 490, for example, a strip or layer of thermoplastic weld
material, a direct
thermal seal, or an adhesive disposed around the periphery 494 of the
attachment surface 468.
The means of attachment 490 may be coincident with or one and the same as the
thermal seal
478.
[00103] In use, the valve strip 440 is placed over the third aperture 484 to
create an
evacuable container that can be evacuated by a user through the region of flow
channels 488
defined between, for example, the attachment surface 468 and the first
sidewall 52, the lid
302, or the container sidewall 316. The valve strip 440 may have any
convenient shape, for
example, including rectangular, circular, elliptical, star shaped, or as
desired to match a
seating surface of an evacuation source (not shown) that may be applied to the
container 300
or the pouch 50.
[00104] In another embodiment of a valve strip 442, as illustrated in FIGS. 22
and 23, a
region on a surface of the second layer 466 that faces the first layer 464 and
that is disposed
between the first and second apertures 474, 476 and bounded by the second
aperture 476 may
also be embossed or otherwise textured with a pattern 465 to define a region
of flow channels
467. In a further embodiment, not shown, a region on a surface of the first
layer 464 that
faces the second layer 466 and that is disposed between the first and second
apertures 474,
476 and at least partially overlapping the second aperture 476 may also be
embossed or
otherwise textured with the pattern 465 to define the region of flow channels
467. In these
embodiments, the first and second layers 464 and 466 are in direct contact in
an intermediate
seal region 487 between the first aperture 474 and the region of flow channels
467, which is
in fluid communication with the third aperture 484 via the second aperture 476
and the region
of flow channels 488. In use, application of vacuum pressure over the exterior
of the first
aperture 474 and a portion of the region of flow channels 467 causes gas
resident within the
region of flow channels 467 to have a greater pressure than the exterior
allowing gas to flow
therethrough.
[00105] It is further contemplated that any of the embodiments of the valve
strip 440, 442
may be provided as a component of a kit or package that comprises a tool, for
example a hole
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punch, for creating an aperture in a wall of a container, and/or a vacuum pump
to evacuate
gas from the interior of the container through the aperture via the valve
strip applied over the
aperture. In this, or in any of the embodiments shown, the valve 40, 340, or
valve strip 440,
442 may be adhered to the pouch 50 or to the container lid 302, film layer
324, or container
body 304 as described herein or by an adhesive known to those skilled in the
art such as
described in Engel et al. U.S. Patent No. 7,178,555 or Hartman et al. U.S.
Patent Application
Publication No. 2006/0030472. Further, it is contemplated that a variety of
containers are
suitable for application of the valves 40, 340, or 440 herein described,
including for example,
pouches, bowls, bottles, Ziploc containers, storage boxes, canisters, or
other containers, and
any lids or covers that may be attachable thereto.
INDUSTRIAL APPLICABILITY
[00106] A container is presented that includes a valve to evacuate gas from a
container.
The valve may include first and second layers of film material that form a
substantially
gastight seal therebetween upon direct contact of the layers. An intermittent
spot seal may
attach the first and second layers of film material. A first aperture through
the first layer is
offset from a second aperture through the second layer. Vacuum pressure
disposed over both
of the first and second apertures, for example, causes the first layer to
separate from the
second layer to allow gas to exhaust from the container.
[00107] Numerous modifications to the present invention will be apparent to
those skilled
in the art in view of the foregoing description. Accordingly, this description
is to be
construed as illustrative only and is presented for the purpose of enabling
those skilled in the
art to make and use the invention and to teach the best mode of carrying out
same. The
exclusive rights to all modifications which come within the scope of the
appended claims are
reserved.
