Note: Descriptions are shown in the official language in which they were submitted.
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STORAGE BAG
FIELD OF THE INVENTION
The present invention relates to storage bags suitable for use in the
containment and
protection of various items, such as food items. The present invention further
relates to a process
for forming a material suitable for constructing a storage bag of the present
invention.
BACKGROUND OF THE INVENTION
The use of storage bags for containing items to be stored, such as food items,
is generally
known in the art. Such storage bags include freezer bags provided in various
sizes for containing
food items, such as meats, in a sealed manner in a freezer environment. It is
desirable for such
bags to have a reclosable or reusable closure effective to provide an airtight
seal. Further, in use
of such storage bags, it is desirable to eliminate any air contained within
the storage bag and seal
opposing sides of the bag to prevent reentry of air in order to minimize
contact of the bag contents
with. air and reduce the possibility of freezer bum, such as may occur as'a
result of dehydration of
a food item stored in a low humidity, freezer environment.
Examples of known storage bags include those described in U.S. Patent Nos.
5,403,094;
5,804,265; 5,965,224; 6,156,363; 6,371,643 and 6,550,966.
There continues to be need for a storage bag suitable for use in containing
stored items in
a freezer environment, and in which an item may be sealably retained in the
bag and air contact
with the stored item may be minimized.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a storage bag is provided
including a bag
body comprising at least two opposing sidewalls including peripheral edges and
the sidewalls
being attached together along at least a portion of the peripheral edges. Each
of the sidewalls
include an outer layer and an inner layer with the inner layers defining
opposing inner faces. At
least one of the inner faces comprising a pressure sensitive composite
material for bonding the
opposing imier faces to each other.
In accordance with another aspect of the invention, a storage bag is provided
including a
bag body comprising at least two opposing sidewalls including peripheral edges
and the sidewalls
being attached together along at least a portion of the peripheral edges. Each
of the sidewalls
comprising an outer surface and an inner surface, the inner surfaces of the
sidewalls being located
in opposing facing relation to each other. At least one of the inner surfaces
comprising a pressure
sensitive composite material for bonding the at least two opposing sidewalls
to each other.
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In accordance with yet another aspect of the present invention, a process for
forming a
storage bag material comprises the steps of: providing a sheet of base film;
providing a pressure
sensitive composite material having an adhesive on one side thereof; moving
the sheet of base
film and the pressure sensitive composite material into overlaying engagement;
and, attaching the
pressure sensitive material to the sheet of base film.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a front elevational view of a reclosable storage bag in accordance
with the
teachings of the present invention;
Fig. 2 is a cross-sectional elevational view taken along line 2-2 in Fig. 1;
Fig. 3 is an enlarged view of a section taken at line 3-3 in Fig. 2,
illustrating an inner
layer of the storage bag of Fig. 1;
Fig. 4 is an enlarged elevational section view of the inner layer illustrated
in Fig. 3;
Fig. 5 is a perspective view of the storage bag of Fig. 1 containing an item
sealed within
the storage bag;
Fig. 6 is cross-sectional elevational view of an alternative configuration of
the storage bag
of Figs. 1 and 2;
Fig. 7 is a perspective view of the storage bag of Fig. 6 containing an item
sealed within
the storage bag;
Fig. 8 is a front elevational view of an alternative embodiment of the
reclosable storage
bag in accordance with the teachings of the present invention;
Fig. 9 is a cross-sectional elevational view taken along line 9-9 in Fig. 8;
Fig. 10 is a front elevational view of a further embodiment of the reclosable
storage bag
in accordance with the teachings of the present invention;
Fig. 11 is a cross-sectional elevational view taken along line 11-11 in Fig.
10; and
Fig. 12 is a diagrammatic view illustrating a process for forming a storage
bag material
for the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figs. 1 and 2, a reclosable storage bag 10 in accordance with the
teachings of
the present invention is shown. The storage bag 10 generally includes two
opposing sidewalls 12,
14 that are attached together along a portion of a periphery of the sidewalls
12, 14, such as along
longitudinal edge seams 16, 18 and along a laterally extending bottom edge 20.
In the illustrated
storage bag 10, the longitudinal edge seams 16, 18 may be formed by sonic
welding, heat sealing,
an adhesive or other conventional attachment means along the edges of the
material forming the
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sidewalls 12, 14, and the bottom edge 20 may be defined by a fold in the
material forming the
sidewalls 12, 14. Further, the bottom edge 20 may also include an edge seam
formed in a manner
similar to that of the longitudinal edge seams 16, 18.
An upper end of the bag 10 includes an open mouth 22 for insertion of articles
into the
interior of the bag 10. A reusable closure 24 comprising complementary mating
elements 26, 28
is located on the interior of the sidewalls 12, 14 at the mouth 22 for
reclosably sealing the moutli
22 of the bag 10. For example, the reusable closure may comprise an
interlocking seal type
closure, and which may or may not include a slider for manipulating opening
and closing of the
bag 10. The present invention is not limited to the illustrated reusable
closure, and examples of
reusable closures that may be employed, and information on their manufacture,
is described in
U.S. Patent Nos. 4,186,786; 4,285,105; 4,363,345; 4,561,109; 5,804,265 and
5,851,070. Other
closures may also be provided within the scope of the described invention.
Referring to Fig. 2, each of the sidewalls 12, 14 forming the bag 10 comprise
plural
layers, including a first layer 30 and a second layer 32 for the sidewall 12
and a first layer 34 and
a second layer 36 for the sidewall 14. The first layers 30, 34 define an outer
film surface for the
bag 10, and the second layers 32, 36 define an inner, article engaging film
for the bag 10. The
second or inner layers 32, 36 comprise a composite material having a
characteristic that enables
inner facing surfaces 38, 40 of the inner layers 32, 36 to adhere to each
other. Alternatively, one
of the second layers 32, 36 may be omitted so that the remaining second layer
will adhere to the
opposing non-adherent inside surface of the first layer. By way of exainple,
the inner layers 32,
36 are formed of a pressure sensitive composite materia141 (Fig. 3) exhibiting
a characteristic of
releasably adhering to an adjacent contacting material surface upon
application of a pressure,
while not adhering to the adjacent contacting surface in the absence of
application of the pressure.
Such composite materials are known in the art and include films formed with a
plurality
of protrusions 42 and valleys 44 (Fig. 4), such as may be formed by an
embossing operation,
where the valleys 44 on an adhesive side of the film are at least partially
filled with a pressure
sensitive adhesive 46. The adhesive 46 is held out of engagement with an
adjacent surface by the
protrusions 42 until a sufficient pressure is applied to the side of the film
opposite the adhesive
side causing at least some of the protrusions 42 to collapse and allow contact
of the adhesive with
the adjacent surface, resulting in adhesion between the coinposite material
and the adjacent
surface.
As described, the currently preferred embodiment of the composite material can
utilize
either raised protrusions, or raised land areas surrounding dimples, to
prevent premature sticking
of the adhesive to an adjacent surface. However, other forms of composite
materials that include
a non-adhesive material to control the tack of the adhesive and prevent the
adhesive from
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attachment to an adjacent surface prior to the application of pressure may
also be used in
accordance with the present invention. Exemplary materials include, without
limitation, release
liners such as silicone coated paper or coatings, inks, varnish, particles
(talc, calcium carbonate,
starch, wax beads and the like), nonwovens, scrim and fibers which are mixed
with or coated
upon the adhesive. The adhesive and/or non-adhesive coatings can either be
continuous or non-
continuous (discrete). Solid, pressure activated adhesives can also be used
including, without
limitation, microencapsulated adhesives that are coated continuously or in
discrete patterns onto a
film. In the case of microencapsulated adhesives and the like, pressure is
applied to rupture the
surface of the microcapsules to bring the adhesive into contact with an
adjacent surface.
Additional details and furtlier examples of such composite materials, and
information on their
manufacture, may be found in U.S. Patent Nos. 5,662,758; 6,489,022; 5,871,607;
6,194,062;
5,965,235; 6,193,918; 6,602,454; U.S. Patent Application Publication
2003/0218274 Al and U.S.
Patent Application Serial No. 10/345,540, entitled Selectively Activatable
Storage Wrap Sheet
Having Discrete Land Areas, filed on January 16, 2003 and assigned to the
assignee of the present
application. However, as would be known to one of skill in the art, other
forms of composite
materials having an adhesive disposed thereon could be used in accordance with
the present
invention including any material having an adhesive disposed continuously or
discontinuously
thereon.
The complementary elements 26, 28 of the reusable closure 24 are located on
opposing
inner faces of the outer layers 30, 34 of the sidewalls 12, 14, and the
composite materia141 of the
inner layers 32, 36 defines upper edges 48, 50 which are illustrated located
in spaced relation
from the reusable closure elements 26, 28. The outer layers 30, 34
additionally include opposing
longitudinal edges which are defined by the longitudinal seam edges 16, 18,
and the inner layers
32, 36 include longitudinal edges located at 49, 51 and located within a seam
area defined by the
longitudinal seam edges 16, 18.
During a use of the storage bag 10, the sidewalls 12, 14 are pressed together
in areas
surrounding the contents of the storage bag 10 (see Fig. 5) to thereby expel
air from the storage
bag 10 and bring the inner facing surfaces 38, 40 of the inner layers 32, 36
into engagement with
each other. When sufficient pressure is applied by pressing the sidewalls 12,
14 together, this
pressure can cause the adhesive on each facing surface 38, 40 to move into
engagement with and
adhere to the opposing facing surface 40, 38, thereby retaining the inner
layers 32, 36 in
engagement with each other and preventing air from reentering the adhered
areas.
In one embodiment, the outer layers 30, 34 may comprise films formed of low-
density
polyethylene (LDPE) having a thickness in the range of approximately 0.1-10.0
mils (0.0254-.254
mm), and preferably in the range of approximately 1.5-2.0 mils (0.0381-0.0508
nun). The inner
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layers 32, 36 may comprise films of high density polyethylene (HDPE) having an
unembossed
thickness in the range of approximately 0.25 to 2.0 mils (0.00635-0.0508 mm)
and an embossed
caliper of approximately 4.0 mils (0.1016 mm). Thus, the LDPE material of the
outer layers 30,
34 provides an outer storage bag surface visually similar to known
commercially available storage
bags. However, it should be noted that other materials and film thicknesses
can be used for either
of the layers of the sidewalls 12, 14.
Examples of materials that may be used for the outer layers 30, 34 include,
without
limitation, thermoplastic materials or a blend of thermoplastic materials. The
films may be made
by a conventional cast or blown film process. Useful thermoplastics include,
without limitation,
polyolefins such as high density polyethylene (HDPE), low density polyethylene
(LDPE), linear
low density polyethylene (LLDPE), and polypropylene (PP); thermoplastic
elastomers such as
styrenic block copolymers, polyolefin blends, elastomeric alloys,
thermoplastic polyurethanes,
thermoplastic copolyesters and thermoplastic polyamides; polymers and
copolymers of polyvinyl
chloride (PVC), polyvinylidene chloride (PVDC), saran polymers, ethylene vinyl
acetate (EVA)
copolymers, cellulose acetates, polyethylene terephthalate (PET), ionomer
(Surlyn ),
polystyrene, polycarbonates, styrene acrylonitrile, aromatic polyesters,
linear polyesters, nylon,
thermoplastic polyvinyl alcohols; foils and metalized films.
Examples of materials that may be used to form the composite material 41 for
the inner
layers 32, 36 include, without limitation, metal foils, such as aluminum foil,
wax paper or grease
proof paper, polymeric films, nonwoven webs, fabrics, paper and combinations
thereof. Some
non-limiting examples of polymeric films include, polyolefin films such as
polyethylene
including high density, linear low density, or low density; ethylene
copolymers, such as ethylene
vinyl acetate (EVA) copolymers or ethylene methyl acrylate (EMA) copolymer,
polyethylene
terephthalate (PET), polyethylene terephthalate glycol (PETG) copolymer;
polypropylenes,
polyethylene-propylene copolymers; polymers and copolymers of polyvinyl
chloride (PVC),
polyvinylidene chloride (PVDC); polystyrene; nylon, and other polymeric films
with similar
properties.
The combination of outer layers 30, 34 surrounding the inner layers 32, 36
provides a
double-walled construction for the storage bag 10 in which the outer layers
30, 34 form an outer
bag providing a first barrier or seal for the contents of the storage bag 10
when the reusable
closure 24 is closed, and the imier layers 32, 36 provide a second barrier or
seal to prevent or
minimize contact of air with the contents of the storage bag 10 when the inner
layers 32, 36 are
pressed together.
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The inner layers 32, 36 of the storage bag 10 are attached to the adjacent
outer layers 30,
34 across substantially the entire surface area of the inner layers 32, 36,
such as may be provided
by combining the composite material 41 with the film material forming the
outer layers 30, 34
during extrusion and formation of the film material for the outer layers 30,
34, as is described
further below. Alternatively the inner layers 32, 36 and outer layers 30, 34
may be adhered to
each other by an adhesive, by static combining, or by other known means for
joining two material
layers.
Referring to Fig. 6, an alternative configuration for the storage bag 10 is
illustrated,
identified by reference numeral 10', and in which elements corresponding to
the previous
configuration are identified with the same reference numerals primed. As with
the previous
configuration of storage bag 10, the storage bag 10' comprises two opposing
sidewalls 12', 14',
each sidewall 12', 14' comprising plural layers, including a first layer 30'
and a second layer 32'
for the sidewall 12' and a first layer 34' and second layer 36' for the
opposing sidewall 14'.
The inner layers 32', 36' are connected to each other and to the outer layers
30', 34'
along the longitudinal seams 16', 18'(Fig. 7), and are alternatively further
joined at an edge seam
along bottom edge 20' formed in a manner similar to the that of the
longitudinal seams 16', 18'.
Further, lateral seams are provided at the upper edges 48', 50' between the
inner layers 32', 36'
and the outer layers 30', 34'.
The inner layers 32', 36' may comprise a composite material where the inner
faces 38',
40' of the inner layers 32', 36' may include a pressure sensitive composite
material 41 of the
same type described for the previous configuration of storage bag 10.
As seen in Fig. 6, the inner layers 32', 36' are substantially unattached to
the outer layers
30', 34' in the area between the longitudinal seams 16', 18' and between the
upper edges 48', 50'
and the bottom edge 20'. Thus, the inner layers 32', 36' may move
independently of the outer
layers 30', 34' for draping and closely conforming to the contents of the
storage bag 10' to
thereby facilitate elimination of air contact witli the contents. Accordingly,
the described storage
bag 10' provides a combined function of protection and ease of use of a
storage bag with the
conformability provided by the pressure sensitive composite material 41.
The storage bag 10' may be used in a manner similar to that described for the
storage bag
10, where a user may apply pressure to the sidewalls 12', 14' of the bag 10'
to cause the inner
faces 38', 40' of the inner layers 32', 36' to adhere to each other and
thereby eliminate or
minimize air contact with the contents of the bag 10', as is illustrated in
Fig. 7. The material of
the inner layers 32, 36 provides drape or conformability characteristics which
permit the inner
layers 32, 36 to act as a wrap which closely confonns to the contours of the
storage bag contents
to minimize air contact with the contents.
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Referring to Figs. 8 and 9, an alternative embodiment for a storage bag 52 in
accordance
with the teachings of the present invention is shown. The storage bag 52
includes two opposing
sidewalls 54, 56 that are attached together along a portion of a periphery of
the sidewalls 54, 56,
such as along longitudinal edge seams 58, 60 and along a laterally extending
bottom edge 62.
The longitudinal edge seams 58, 60 may be formed by sonic welding, heat
sealing, an adhesive or
other conventional attachment means along the edges of the material forming
the sidewalls 54, 56,
and the bottom edge 62 may be defined by a fold in the material forming the
sidewalls 54, 56.
Further, the bottom edge 62 may alternatively include an edge seam formed in a
manner similar to
that of the longitudinal edge seams 58, 60.
An upper end of the storage bag 52 includes an open mouth 64 for insertion of
articles
into the interior of the storage bag 52. A reusable closure 66 comprising
complementary
interlocking mating elements 68, 70 is located on the sidewalls 54, 56 at the
mouth 64 for
reclosably sealing the mouth 64 of the storage bag 52. In the illustrated
example, the reusable
closure 66 comprises a slider 72 for manipulating the complementary
interlocking mating
elements 68, 70 into closed and open positions. However, it should be
understood that an
interlocking seal type closure, such as is illustrated in Figs 1 and 2, or any
other reclosable
closure, for example as described in the above-referenced patents relating to
closure devices, may
be provided.
As shown in Fig. 9, the sidewalls 54, 56 each comprise a film layer formed of
a
composite material having a characteristic that enables inner facing surfaces
74, 76 of the
respective sidewalls 54, 56 to releasably adhere to each other. By way of
example, the sidewalls
54, 56 are formed of a pressure sensitive composite material exhibiting the
characteristic of
releasably adhering to an adjacent contacting material surface upon
application of pressure, while
not adhering to the adjacent contacting surface in the absence of application
of the pressure, such
as a composite material constructed in accordance with the above-referenced
teachings relating to
the composite material 41, described for the inner layers of the storage bags
10, 10'.
Alternatively, one of the sidewalls 54, 56 may be formed of a pressure
sensitive
composite material, such as a composite material constructed in accordance the
above-referenced
teachings relating to composite materia141, and the opposing sidewall 54, 56
may be formed of a
non-adherent surface, such as a smooth material surface, where the one
sidewall 54, 56 will
adhere to the opposing non-adhesive surface to form a conforming seal around
the contents of the
storage bag 52. Accordingly, the described storage bag 52 provides drape and
conformability
characteristics around the contents of the storage bag 52 to substantially
isolate the contents from
air, while also providing the ease of use of a storage bag construction
including a reusable closure
66 to seal the storage bag mouth 64.
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It should be noted that the material forming the sidewalls 54, 56 of the
storage bag 52
comprises an HDPE film, although other film materials providing the same
composite material
characteristics as those associated with the pressure sensitive composite
material 41 may also be
used. For example, the materials described above for the composite material of
the inner layers
32, 36 may be provided for the sidewalls 54, 56.
Referring to Figs. 10 and 11, an alternative embodiment for a storage bag 78
in
accordance with the teachings of the present invention is shown. The storage
bag 78 includes two
opposing sidewalls 80, 82 that are attached together along a portion of a
periphery of the
sidewalls 80, 82, such as along longitudinal edge seams 84, 86 and along a
laterally extending
bottom edge 88. The longitudinal edge seams 84, 86 may be formed by sonic
welding, heat
sealing, an adhesive or other conventional attachment means along the edges of
the material
forming the sidewalls 80, 82, and the bottom edge 88 may be defined by a fold
in the material
forming the sidewalls 80, 82. Further, the bottom edge 88 may alternatively
include an edge seam
formed in a manner similar to that of the longitudinal edge seams 84, 86.
An upper end of the storage bag 78 includes an open mouth 90 for insertion of
articles
into the interior of the storage bag 78. A reusable closure 92 comprising
complementary mating
elements 94, 96 is 'attached to the sidewalls 80, 82 at the mouth 90 for
reclosably sealing the
mouth 90 of the storage bag 78. In the illustrated example, the reusable
closure 92 comprises an
interlocking seal type closure. However, it should be understood that a slider
zipper seal type
closure, such as is illustrated in Figs 8 and 9, or any other reusable
closure, for example as
described in the above-referenced patents relating to closure devices, may be
provided.
The storage bag 78 includes a strip-like secondary seal 98 located in spaced
relation to the
reusable closure 92. The secondary seal 98 comprises respective secondary seal
elements 100,
102 positioned on inner facing surfaces 104, 106 of the sidewalls 80, 82,
located just below the
complementary elements 94, 96. The illustrated secondary seal elements 100,102
comprise a
composite material having a characteristic that enables inner faces 108, 110
of the secondary seal
elements 100, 102 to releasably adhere to each other. For example, a
coniposite material having
the characteristic of adhering to an adjacent contacting material surface upon
application of a
pressure, while not adhering to the adjacent contacting surface in the absence
of application of
pressure, may be provided for the secondary sealing elements 100, 102, such as
a composite
material constructed in accordance with the above-referenced teachings
relating to the coinposite
material 41. Of course, only one of the secondary seal elements 100, 102 could
also be used to
form the secondary seal 98. Further, secondary seal elements 100,102 can be
provided
individually as continuous and/or discontinuous elements and in combination
provide a
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continuous or discontinuous secondary seal 98 as could be recognized by one of
ordinary skill in
the art.
The sidewalls 80, 82 of the storage bag 78 may be formed of a LDPE film, or
any of the
films described herein, with reference to the outer walls 30, 34 of the
storage bag 10. The
secondary seal elements 100, 102 may be formed of a HDPE film or any of the
films describe
with reference to the composite material 41 forming the inner walls 32, 36 of
the storage bag 10.
The secondary seal 98 preferably provides a visually recognizable seal
separate and
distinct from the reusable closure 92. Alternatively, the secondary seal 98
may be provided
within the same area as the reusable closure 92.
The storage bag 78 provides a double-seal against entry of air to the interior
of the storage
bag 78, as well as provides a double-seal against odors entering or leaving
the storage bag 78.
The reusable closure 92 and the secondary seal element 98 of the double-seal
construction further
provides an additional closure element to secure the contents of the storage
bag 78 should one of
the seals inadvertently open.
In an alternative configuration of the storage bag 78, only the composite
material of the
secondary seal 98 may be provided at the mouth 90 of the storage bag 78 to
provide a single
resealable closure element for the storage bag 78.
In other alternative configurations of the storage bag 78, the composite
material
secondary seal 98 may be located above the reusable closure 92; a pair of
composite material
secondary seals 98 may be provided, one on either side of the reusable closure
92; or a pair of
composite material secondary seals 98 may be provided as first and second
seals for the storage
bag 78 without the reusable closure 92.
In a further alternative configuration of the storage bag 78, the secondary
seal 98 may be
formed of a reusable closure similar to the reusable closure 92. For example,
the storage bag 78
may be formed with a slider zipper seal closure for the reusable closure 92,
and the secondary seal
98 may comprise an interlocking seal closure. Alternatively, both the closure
elements 92 and 98
may comprise an interlocking seal closure.
The above-described embodiments provide a bag stiucture for eliminating or
minimizing
air contact with the contents of a storage bag, which is particularly
advantageous for storage bags
used for freezing food articles such as meats. In addition to the above-
described composite
material incorporated in a bag structure, at least one of the bag walls may be
provided with a
passage, such as a valve passage (not shown), for permitting suction to be
applied to evacuate air
from the interior of the storage bag. The valve passage can be located
anywhere in the bag below,
or as a part of, the interlocking closure but is preferably near the top of
the bag. The film that is
opposite to the valve and located in proximity to the valve passage
preferentially contains no
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adhesive and is textured such that the film opposite to the valve does not
block off the opening to
the valve passage or significantly restrict the air flow through the valve
passage. The valve
passage may be any opening in the bag that permits the passage of air through
the wall of the bag.
The valve is preferably a one-way valve such that air cannot return into the
bag. However, one of
skill in the art would be able to select a particular valve or valve stiucture
that provides the
function desired in the final product.
In addition to withdrawing air through a valve passage, air can also be
withdrawn through
the primary bag opening prior to the interlocking strips being closed. One
method for doing this
is a suction nozzle that is placed into the partially closed bag whereby the
bag is held tightly
around the nozzle, for example through the assistance of clamps. Another
method for
withdrawing air through the primary opening of the bag is througli the use of
a vacuum sealing
food storage device that utilizes a small vacuum chamber (e.g., as described
in US Patent No.
4,941,310). In both cases, it is desirable to use a bag of the current
invention that is textured on
the inside surface of the bag but without adhesive at the top of the bag
thereby allowing good air
flow. The applied suction forces the two sides of the bags into intimate
contact which are held
together by the adhesive on the remaining portion of the bag. The two sides of
the bag are held
together thereby allowing excellent air evacuation from the bag and
restricting air from reentering
the bag. Also, other materials may be incorporated in one or more of the above-
described
embodiments, such as films formed of other polymer materials than those
specifically mentioned
herein, including the so-called cling-wrap materials, to facilitate closure of
a storage bag from
entry of air.
Referring to Fig. 12, a process for forming a storage bag material for the
present invention
is illustrated diagrammatically and includes an extruder 112 followed by a die
114 for forming a
base material comprising a film layer 116, such as a LDPE layer of the film
material in a molten,
or softened, state, prior to a chilling step. The fluid film layer 116 is fed
to a nip between a chill
roll 118 and a nip roll 1201ocated at a water bath 122. A layer of composite
material, such as the
embossed composite materia141, is fed from a material supply 124 into the nip
between the chill
roll 118 and the nip roll 120 with the adhesive side of the composite
materia141 facing away from
the fluid film 116. The fluid film 116 bonds to the composite material 41 as
the two layers of
material 116, 41 pass through the nip of the chill roll 118 and the nip roll
120 in order to fonn a
double-layer sheet of material 126 which may be used to constiuct storage bags
having a
composite material inner layer. Attachinent of the layer of composite material
to the base material
may be done by techniques known by those skilled in the art including thermal
lamination,
adhesive lamination, mechanical fastening such as embossing and the like. It
is also contemplated
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that the base layer can be fonned as a composite material with bags then being
formed from the
resulting composite material.
Another alternative embodiment of the storage bag of the present application
may
comprise a multibag having at least an inner liner bag and an outer support
bag, the inner liner
bag forming or having a composite material on at least one inner surface of
the bag. The
composite material can be formed with or without a pressure sensitive adhesive
disposed thereon.
If a pressure sensitive adhesive is used, a composite material useful for an
altemative embodiment
can be fomled as discussed in the embodiments described supra. See U.S. Patent
No. 5,804,265
for additional information regarding suitable multibag structures appropriate
for construction of
such an embodiment. Yet another alternate embodiment of the storage bag of the
present
application comprises a multi-layered bag having at least one liner film and
an outer support bag.
The liner film(s) has a first sidewall and a second sidewall at least one of
which forms or having a
composite material thereon. A first end of the liner film is the only portion
that is attached to an
inner surface of the outer support bag with the second end of the film liner
being free of the outer
bag. The length of the inner liner can be varied so that the second end ranges
from approximately
as long as the outer support bag is deep or so that the film is two or more
times the depth of the
outer support bag. See U.S. Patent No. 6,371,643 for additional infonnation
regarding a storage
bag structure with at least one inner film appropriate for construction of
this embodiment.
It is contemplated that storage bags made in accordance with the teachings of
the present
invention can include any number of layers and that any number of layers can
be used in any of
the films used to make the bags by using processes known in the art including,
without limitation,
co-extrusion and lamination. For example, nylon or ethylene vinyl alcohol
copolymer layers can
be used to improve the flavor, aroma, and oxygen barrier properties of the
bags. Further, one of
skill in the art will realize that individual layers, or the components
comprising an individual
layer, utilized for the bag of the present invention can be selected to
provide a specific functional
or asthetic requirement. In an exemplary, but non-limiting example, a UV-
resistant layer can be
provided within the structure of a layer comprising the bag of the present
invention to prevent the
photo-degradation of a product positioned within the bag.
AII documents cited in the present application are
not to be construed as an admission that it is prior art with respect to
the present invention.
While particular embodiments of the present invention have been illustrated
and
described, it would be obvious to those slalled in the art that various other
changes and
modifications can be made without departing from the spirit and scope of the
invention. It is
CA 02571246 2006-12-18
WO 2006/012083 PCT/US2005/021747
12
therefore intended to cover in the appended claims all such changes and
modifications that are
within the scope of this invention.
