U.S. patent application number 13/395151 was filed with the patent office on 2012-07-12 for resealable laminate for heat sealed packaging.
This patent application is currently assigned to AVERY DENNISON CORPORATION. Invention is credited to Martin Daffner, Xingrong Duan, Bassam Hallack.
Application Number | 20120177307 13/395151 |
Document ID | / |
Family ID | 43034668 |
Filed Date | 2012-07-12 |
United States Patent
Application |
20120177307 |
Kind Code |
A1 |
Duan; Xingrong ; et
al. |
July 12, 2012 |
Resealable Laminate for Heat Sealed Packaging
Abstract
A resealable package assembly is described. The package assembly
includes a selectively positionable flap that covers an aperture or
enables access through the aperture into the package. The flap and
package include provisions for releasably engaging the flap to the
package to seal the interior of the package. Provisions for
grasping the tab and indicating whether tampering has occurred are
also described.
Inventors: |
Duan; Xingrong; (Shanghai,
CN) ; Daffner; Martin; (Long Beach, CA) ;
Hallack; Bassam; (Newport, AU) |
Assignee: |
AVERY DENNISON CORPORATION
Pasadena
CA
|
Family ID: |
43034668 |
Appl. No.: |
13/395151 |
Filed: |
September 13, 2010 |
PCT Filed: |
September 13, 2010 |
PCT NO: |
PCT/US10/48558 |
371 Date: |
March 9, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61241416 |
Sep 11, 2009 |
|
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Current U.S.
Class: |
383/211 ;
428/195.1 |
Current CPC
Class: |
B32B 27/302 20130101;
B32B 2307/7246 20130101; B65D 75/5855 20130101; B32B 2255/10
20130101; B32B 2307/514 20130101; Y10T 428/24802 20150115; B32B
2250/24 20130101; B65D 33/00 20130101; B65D 65/14 20130101; B32B
2307/58 20130101; B32B 27/36 20130101; B32B 27/325 20130101; B32B
27/34 20130101; B65D 33/24 20130101; Y10T 428/1452 20150115; Y10T
428/1476 20150115; B32B 7/03 20190101; B32B 27/10 20130101; B32B
2270/00 20130101; B32B 25/08 20130101; B32B 2307/75 20130101; B32B
27/18 20130101; B32B 27/304 20130101; Y10T 428/1457 20150115; B32B
27/08 20130101; B32B 27/308 20130101; B32B 27/286 20130101; B32B
27/322 20130101; B32B 2307/748 20130101; B32B 2439/46 20130101;
B65D 2575/586 20130101; Y10T 428/1462 20150115; B32B 25/14
20130101; B65D 65/40 20130101; B32B 2439/70 20130101; B32B 2439/00
20130101; B32B 27/306 20130101; B32B 27/40 20130101; B32B 2255/26
20130101; B65D 75/5833 20130101; Y10T 428/1424 20150115; B32B 7/12
20130101; B32B 2255/205 20130101; B32B 2307/31 20130101; Y10T
428/24942 20150115; B65D 33/20 20130101; B32B 27/32 20130101; B32B
7/06 20130101; B32B 2307/7244 20130101 |
Class at
Publication: |
383/211 ;
428/195.1 |
International
Class: |
B32B 3/00 20060101
B32B003/00; B65D 33/18 20060101 B65D033/18 |
Claims
1. A resealable packaging laminate comprising: an outer layer, the
outer layer defining an outer face; a pressure sensitive adhesive
layer adjacent to the outer layer; an inner sealing layer, the
inner sealing layer defining an inner face; a filmic layer adjacent
to the inner sealing layer; a release layer disposed between the
pressure sensitive adhesive layer and the filmic layer, the release
layer at least in partial contact with the pressure sensitive
adhesive layer; the inner face defining an inner die cut extending
through the sealing layer, the filmic layer, and the release layer
to thereby define an inner flap portion; the outer face defining an
outer die cut extending through the outer layer and the pressure
sensitive adhesive layer to thereby define an outer flap portion;
the inner flap portion and the outer flap portion being secured to
each other to thereby provide a positionable flap partially
connected to the packaging laminate; wherein the outer die cut and
the inner die cut define a resealable region extending between the
outer die cut and the inner die cut, the resealable region in the
flap including a portion of the pressure sensitive adhesive layer
and the resealable region in the packaging laminate including a
portion of the release layer.
2. The packaging laminate of claim 1 wherein the pressure sensitive
adhesive layer exhibits a relatively uniform composition at all
locations in the laminate.
3. The packaging laminate of claim 1 wherein the flap is
selectively positionable between (i) an open position in which at
least a portion of the flap is spaced from the packaging laminate,
and (ii) a closed position in which the flap is sealingly contacted
with the packaging laminate.
4. The packaging laminate of claim 1 wherein upon the flap being in
an open position, at least a portion of the pressure sensitive
adhesive layer in the resealable region of the flap is exposed.
5. The packaging laminate of claim 1 wherein upon the flap being in
an open position, at least a portion of the release layer in the
resealable region of the packaging laminate is exposed.
6. The packaging laminate of claim 1 further comprising: a barrier
layer disposed between the filmic layer and the inner sealing
layer.
7. The packaging laminate of claim 6 wherein the barrier layer
disposed between the filmic layer and the inner sealing layer is a
first barrier layer, the laminate further comprising: a second
barrier layer disposed between the outer layer and the pressure
sensitive adhesive layer.
8. The packaging laminate of claim 1 wherein the outer die cut
extends through a barrier layer between the filmic layer and the
inner sealing layer.
9. The resealable packaging laminate of claim 1 wherein the inner
flap portion and the outer flap portion are secured to each other
by contact between the pressure sensitive layer and the release
layer.
10. The releasable packaging laminate of claim 1 wherein the inner
die cut defines an aperture extending through the packaging
laminate.
11. The packaging laminate of claim 1 wherein the inner sealing
layer comprises a material selected from the group consisting of
linear low density polyethylene (LLDPE), copolymers of
polypropylene (Co-PP), terpolymers of polypropylene (Ter-PP), and
glycol-modified polyethylene terephthalate (PETG), and combinations
thereof.
12. The packaging laminate of claim 1 wherein the filmic layer
comprises a material selected from the group consisting of
co-extruded oriented polypropylene (OPP), co-extruded oriented
polyethylene terephthalate (BOPET), polyvinyl chloride (PVC),
ortho-phthalaldehyde (OPA), and combinations thereof.
13. The packaging laminate of claim 1 wherein the pressure
sensitive adhesive layer comprises a polymeric blend of butyl
acrylate and 2-ethyl-hexyl acrylate monomers.
14. The packaging laminate of claim 1 wherein the release layer
comprises silicone.
15. The packaging laminate of claim 1 wherein the release layer
includes a silicone slip agent modified co-extruded polypropylene
film skin layer.
16. The packaging laminate of claim 1 wherein the outer layer
comprises a material selected from the group consisting of
polyethylene terephthalate (PET), oriented polypropylene (OPP),
polyvinyl chloride (PVC), ortho-phthalaldehyde (OPA), copolymers
thereof, and combinations thereof.
17. The packaging laminate of claim 6 wherein the barrier layer
exhibits an oxygen permeability of less than 50 cc/m.sup.2/24
hours.
18. The packaging laminate of claim 6 wherein the barrier layer
exhibits a water permeability of less than 50 cc/m.sup.2/24
hours.
19. The packaging laminate of claim 6 wherein the barrier layer
comprises a material selected from the group consisting of
polyvinylidene chloride (PVDC), ethylene vinyl alcohol polymer
(EVOH, PVA), nylon polymers, and combinations thereof.
20. The packaging laminate of claim 6 wherein the barrier layer
includes a metalized aluminum layer.
21. The packaging laminate of claim 1 wherein the the flap has an
opening force from about 1 N/in to about 10 N/in.
22. The packaging laminate of claim 1 wherein the flap is sealingly
engaged to the packaging laminate.
23. The packaging laminate of claim 1 further comprising: a
printing layer disposed on the outer layer, wherein the printing
layer provides the outer face of the flap.
24. The packaging laminate of claim 1 wherein the outer face
further defines at least one tamper identifier, the tamper
identifier defined in the resealable region.
25. The packaging laminate of claim 24, wherein the tamper
identifier includes a tamper die cut extending through the outer
layer, the pressure sensitive adhesive layer, and the release
layer.
26. The packaging laminate of claim 25, wherein the tamper die cut
extends through a barrier layer disposed between the outer layer
and the pressure sensitive adhesive layer.
27. The packaging laminate of claim 24, wherein the at least one
tamper identifier having a shape selected from the group consisting
of a circle, a square, a rectangle, an oval, a triangle, and
combinations thereof.
28. The packaging laminate of claim 1 wherein the inner die cut is
continuous.
29. The packaging laminate of claim 1 wherein the outer die cut
includes at least one non-continuous die cut region, each
non-continuous die cut region adapted to sever upon an initial
opening operation in which the flap of the packaging laminate is
initially opened.
30. The packaging laminate of claim 1 wherein the outer die cut
includes two non-continuous die cut regions, the two non-continuous
die cut regions separated by a portion of the outer die cut.
31. The packaging laminate of claim 30 wherein the portion of the
outer die cut separating the two non-continuous die cut regions is
arcuate in shape.
32. The packaging laminate of claim 1, the packaging laminate
further comprising a region of adhesive deadening material disposed
within the resealable region, and between the pressure sensitive
adhesive layer and the release layer.
33. The packaging laminate of claim 32 wherein the adhesive
deadening material is proximate to at least one non-continuous die
cut region.
34. The packaging laminate of claim 32 wherein the adhesive
deadening material is disposed proximate the arcuate portion of an
outer die cut separating two non-continuous die cut regions.
35. A resealable bag container, the container including two end
sections and at least one multilayer side wall extending
therebetween to thereby define a hollow interior, the container
including a selectively positionable flap, the flap at least
partially connected to a portion of the side wall of the container
and positionable over an aperture defined in the side wall, the
flap defining a first sealing region extending along an inner face
of the flap, the flap including an adhesive layer exposed in the
first sealing region; the side wall defining a second sealing
region extending about the aperture, the side wall including a
release layer exposed in the second sealing region; the flap
configured to releasably seal with the side wall by contacting the
exposed adhesive layer of the flap with the exposed release layer
of the side wall; wherein the multilayer side wall of the container
includes an adhesive layer having the same composition as the
adhesive layer in the flap.
36-60. (canceled)
61. A resealable packaging laminate comprising: an outer laminate
portion including a pressure sensitive adhesive layer, the outer
laminate portion defining an outer die cut, the outer die cut
extending across a region of the outer laminate to define an outer
flap portion, the outer flap portion at least partially connected
to the packaging laminate; an inner laminate portion including a
release layer at least partially in contact with the pressure
sensitive adhesive layer, the inner laminate portion defining an
inner die cut, the inner die cut extending across a region of the
inner laminate to define an inner flap portion, the inner flap
portion at least partially connected to the packaging laminate;
wherein the outer flap portion overlies the inner flap portion and
is secured thereto to form a flap at least partially connected to
the packaging laminate; the outer die cut and the inner die cut
defining (i) a flap resealing area in the flap extending between
the outer die cut and the inner die cut, a portion of the pressure
sensitive adhesive layer being selectively exposed in the flap
resealing area, and (ii) a flap receiving area in the packaging
laminate extending between the outer die cut and the inner die cut,
a portion of the release layer being selectively exposed in the
flap receiving area; wherein the flap is selectively positionable
between (i) a seal position in which the pressure sensitive
adhesive layer in the flap resealing area of the flap is in contact
with the release layer in the flap receiving area of the packaging
laminate, and (ii) an open position in which the flap is at least
partially spaced from the packaging laminate to thereby expose at
least a portion of the pressure sensitive adhesive layer in the
flap resealing area of the flap and a portion of the release layer
in the flap receiving area of the packaging laminate.
62-81. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/241,416 filed Sep. 11, 2009, which is
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to heat sealable, flexible
wall, disposable packages that are also resealable.
BACKGROUND OF THE INVENTION
[0003] A wide array of resealable packages or containers are known.
Typically, a container such as in the form of a flexible bag or
rigid walled housing, is provided with an opening that serves to
provide access to the interior of the container. A lid or cover is
positioned over the opening and bonded to the container, typically
by heat sealing, to enclose and seal the container interior and its
contents from the external environment. For bag type containers, a
portion of the flexible wall of the bag may serve as the cover and
be folded or otherwise positioned over an opening in the bag. A
reseal feature enables the lid or cover, or a portion thereof, to
be removed or otherwise repositioned so as to allow access to the
interior of the container. After accessing the interior of the
container, the lid or cover can be appropriately positioned over
the opening and engaged with the container to thereby reseal the
container.
[0004] Numerous strategies have been devised for the lid or cover
to overlay a container opening and engage the container to thereby
seal the interior of the container from the outside environment. An
example of a sealing strategy is the provision of a layer of a
pressure sensitive adhesive on the contacting surfaces of the lid
or cover, and/or the corresponding region of the container
extending about the periphery of the opening. This latter strategy
is widely used, particularly for disposable packaging as used for
storing and preserving perishable items such as food in which it is
desirable to minimize exposure to air.
[0005] Although satisfactory in certain respects, the production of
resealable packaging is relatively expensive. Currently known
resealable, flexible wall, disposable packaging utilizes different
adhesive compositions at different locations in the package. For
example, a permanent adhesive may be used along seams or other end
regions for sealing, and a pressure sensitive adhesive may be used
in the region of a resealable lid or cover. This increases
manufacturing complexity and cost, and also reduces production
rates of the packaging. Accordingly, it would be desirable to
provide a new disposable packaging container or assembly and
particularly one that is resealable, that could be manufactured in
a high speed and high volume environment. Moreover, it would be
desirable to provide a resealable package configuration that was
relatively inexpensive as compared to currently known resealable
packages.
SUMMARY OF THE INVENTION
[0006] The difficulties and drawbacks associated with previous
systems and methods are overcome by the present invention for a
resealable package assembly. In a one aspect of the invention, a
resealable packaging laminate is provided comprising an outer layer
defines an outer face. The packaging laminate also comprises a
pressure sensitive adhesive layer adjacent to the outer layer. The
packaging laminate further comprises an inner sealing layer, the
inner sealing layer defining an inner face. The packaging laminate
also comprises a filmic layer adjacent to the inner sealing layer.
And, the packaging laminate additionally comprises a release layer
disposed between the pressure sensitive adhesive layer and the
filmic layer. The release layer is at least in partial contact with
the pressure sensitive adhesive layer. The inner face defines an
inner die cut extending through the sealing layer, the filmic
layer, and the release layer to thereby define an inner flap
portion. The outer face defines an outer die cut extending through
the outer layer and the pressure sensitive adhesive layer to
thereby define an outer flap portion. The inner flap portion and
the outer flap portion are secured to each other to thereby provide
a positionable flap partially connected to the packaging laminate.
The outer die cut and the inner die cut define a resealable region
extending between the outer die cut and the inner die cut. The
resealable region in the flap includes a portion of the pressure
sensitive adhesive layer and the resealable region in the packaging
laminate includes a portion of the release layer.
[0007] In another aspect, the present invention provides a
resealable bag container. The container includes two end sections
and at least one multilayer side wall extending therebetween to
thereby define a hollow interior. The container includes a
selectively positionable flap, the flap at least partially
connected to a portion of the side wall of the container and
positionable over an aperture defined in the side wall. The flap
defines a first sealing region extending along an inner face of the
flap, the flap including an adhesive layer exposed in the first
sealing region. The side wall defines a second sealing region
extending about the aperture, the side wall including a release
layer exposed in the second sealing region. The flap is configured
to releasably seal with the side wall by contacting the exposed
adhesive layer of the flap with the exposed release layer of the
side wall. The multilayer side wall of the container includes an
adhesive layer having the same composition as the adhesive layer in
the flap.
[0008] In yet another aspect, the present invention provides a
resealable packaging laminate comprising an outer laminate portion
including a pressure sensitive adhesive layer. The outer laminate
portion defines an outer die cut. The outer die cut extends across
a region of the outer laminate to define an outer flap portion. The
outer flap portion is at least partially connected to the packaging
laminate. The packaging laminate also comprises an inner laminate
portion including a release layer at least partially in contact
with the pressure sensitive adhesive layer. The inner laminate
portion defines an inner die cut. The inner die cut extends across
a region of the inner laminate to define an inner flap portion. The
inner flap portion is at least partially connected to the packaging
laminate. The outer flap portion overlies the inner flap portion
and is secured thereto to form a flap at least partially connected
to the packaging laminate. The outer die cut and the inner die cut
further define (i) a flap resealing area in the flap extending
between the outer die cut and the inner die cut, a portion of the
pressure sensitive adhesive layer being selectively exposed in the
flap resealing area, and (ii) a flap receiving area in the
packaging laminate extending between the outer die cut and the
inner die cut, a portion of the release layer being selectively
exposed in the flap receiving area. The flap is selectively
positionable between (i) a seal position in which the pressure
sensitive adhesive layer in the flap resealing area of the flap is
in contact with the release layer in the flap receiving area of the
packaging laminate, and (ii) an open position in which the flap is
at least partially spaced from the packaging laminate to thereby
expose at least a portion of the pressure sensitive adhesive layer
in the flap resealing area of the flap and a portion of the release
layer in the flap receiving area of the packaging laminate.
[0009] As will be realized, the invention is capable of other and
different embodiments and its several details are capable of
modifications in various respects, all without departing from the
invention. Accordingly, the drawings and description are to be
regarded as illustrative and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view illustrating a preferred
embodiment resealable packaging laminate and positionable flap in
accordance with the present invention.
[0011] FIG. 2 is a cross sectional view taken across line 2-2 in
FIG. 1 illustrating in greater detail a preferred sealing
configuration of the flap.
[0012] FIG. 3 is an exploded schematic view of a preferred assembly
used in the laminates described herein.
[0013] FIG. 4 is a schematic perspective view of a preferred
embodiment resealable bag container and positionable flap in
accordance with the present invention.
[0014] FIGS. 5-10 illustrate various preferred tab configurations
and tamper identifying provisions in accordance with the present
invention.
[0015] FIG. 11 is a detailed schematic view illustrating the
assembly of FIG. 3 formed into a preferred laminate and resealable
flap in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] The present invention provides a resealable package assembly
optionally having high barrier properties, which is relatively
simple in construction and manufacture, and which can be readily
initially opened and securely resealed. The present invention also
provides a laminate assembly with a resealable flap that can be
used in a wide array of packaging applications. The packaging
assemblies and laminates described herein are particularly useful
in forming heat sealed, flexible wall, disposable bag or bag-like
containers which are resealable.
[0017] A significant feature of the present invention is the
incorporation of a release layer within the multilayer laminate,
and preferably immediately adjacent to a pressure sensitive
adhesive layer. As explained in greater detail herein, the use of a
release layer in the laminate and particularly in a corresponding
flap member, significantly reduces the amount of force otherwise
required to initially open a sealed container. This feature
promotes ease of use of a package system using the preferred
laminate and flap configuration. The incorporation of a release
layer in conjunction with particular cut lines as described herein
also provides a designated rupture or separation interface between
portions of the laminate during initial opening of a sealed package
or container. The provision of such a separation interface
significantly reduces the occurrence of tearing or unintended
severing of the laminate, thereby preserving the sealing integrity
of the package. These and other advantages of the preferred
embodiment laminates, flap configurations, and package assemblies
are described in greater detail herein.
[0018] The packaging laminates as described herein generally
comprise a plurality of layers, such as from 2 to 12 or more, and
preferably from 5 to 7. Generally, the laminates include an outer
layer, an optional barrier layer, a pressure sensitive adhesive
layer, a release layer, a filmic layer, and a sealing layer. An
optional cover printing layer may also be included. The layers may
be in a variety of different arrangements, however typically the
outer layer provides an outer face for the packaging laminate and
the sealing layer provides an inner face for contacting and
sealing. The pressure sensitive layer and the release layer are
preferably immediately adjacent to one another to provide a reseal
function as described herein. The optional barrier layer is
typically disposed adjacent the outer layer, but the present
invention includes laminates in which the barrier layer is located
elsewhere. Similarly, the filmic layer can be located at nearly any
location in the laminate, however is typically located adjacent to
the sealing layer.
[0019] In accordance with the present invention, a unique
configuration and method of forming is provided for a selectively
positionable and resealable flap member. The term "flap" as used
herein refers to a portion of the laminate, such as a portion of a
side wall when the laminate is used to form a container or package,
that is partially severed from a remainder portion of the laminate
so that the portion is selectively positionable with respect to the
remainder portion. The flap portion remains connected to the
remainder portion as described in greater detail herein.
[0020] The various preferred flaps can be readily formed in a rapid
and economical manner. In accordance with the invention, a unique
combination of cuts, incisions, or the like, formed in certain
layers of the laminates enables inexpensive manufacture of
resealable openings for packages.
[0021] In accordance with other features of the present invention,
various tabs for the flaps are provided which facilitate opening
and grasping of the flaps. Another feature described herein serves
to reduce the extent of adhesive engagement between a flap and a
corresponding receiving surface.
[0022] The present invention also provides various tamper
identifiers. The tamper identifiers provide indication that the
package, flap, or laminate has been initially opened. These and
other aspects are all described in greater detail herein.
[0023] Outer Layer
[0024] The preferred multilayer laminate includes an outer
substrate to provide support for the flap and packaging side wall
and particularly for an outermost portion of the flap resulting
from initial opening of the container and thus at least partial
separation of the flap from the side wall. The outer substrate can
be formed from a wide array of materials such as polyolefin film
materials or paper, cardboard, or other paper-based materials.
Representative materials for the outer substrate include, but are
not limited to, polyethylene (PE), polypropylene (PP), both
oriented and nonoriented, and co-extruded with or without
copolymers thereof. Depending upon the particular end use
application, another example of a potentially suitable film for the
cover outer substrate is a layer of polyvinyl chloride (PVC) and
copolymers thereof. Additional materials include, but are not
limited to, polyethylene terephthalate (PET), oriented
polypropylene (OPP), polyvinyl chloride (PVC), and
ortho-phthalaldehyde (OPA). For many applications, PET is
preferred.
[0025] The outer substrate or layer can be utilized at various
thicknesses in the laminate. The outer substrate can have a typical
thickness of from about 12 to about 60 microns, and a preferred
thickness of from about 12 to about 25 microns.
[0026] Since the outer face of the outer substrate will likely
constitute the outermost surface of the flap or side wall, it is
desirable that the material selected for the outer substrate, at
least along this outwardly directed face, exhibit attractive
printability characteristics.
[0027] Printability is typically defined by the sharpness and
brightness of the image and by ink anchorage. The sharpness is
closely related to the surface tension of the print surface. The
ink anchorage is often tested by a tape test (Finat test: FTM21).
In general, PVC is printable with a variety of inks intended to be
used with PVC. In most occasions the inks are water-based
(especially in the US) or designed for UV drying (especially in
Europe). In general, all polyolefin films can be printed with UV
inks after on-press corona treatment, PE being better than PP
mainly on ink adhesion. For waterbased inks an additional primer or
topcoat is preferred to achieve good ink anchorage.
[0028] As explained herein, the flap or side wall of the laminate
may include an optional printing layer disposed on an outer face of
the outer substrate.
[0029] Barrier Layer
[0030] The preferred multilayer laminate includes an optional
barrier material layer to promote the sealing characteristics of
the flap and side wall and resulting sealed flap and side wall
assembly. Typically, it is desirable for the barrier material to
exhibit resistance to oxygen and/or water vapor transport or
diffusion through the material. This is particularly desirable for
sealing applications involving certain foods. A wide range of
barrier materials can be used for the barrier material layer. The
selection of the barrier material(s) is largely dictated by the
degree of sealing required and hence, by the contents for which the
sealing assembly is to house. Representative materials for use in
the barrier material layer include, but are not limited to,
polyvinyl alcohol (PVOH, PVA) and ethylene vinyl alcohol (EVOH)
polymers. A well known and preferred barrier material is
polyvinylidene chloride (PVDC). It is also contemplated that nylon
and various nylon-based polymers known in the art could be used.
Various metalized layers such as using aluminum can be used. It is
further contemplated that combinations of these materials could be
used, and in particular, multiple films of these materials could be
utilized. An excellent discussion of barrier materials and their
characteristics is provided in US Patent Application Publication
2004/0033379, owned by the assignee of the present application.
Preferred materials for the barrier material include PVDC, EVOH,
and combinations thereof. Another preferred material for the
barrier material is a metalized aluminum layer.
[0031] The barrier material is typically utilized at relatively
small thicknesses in the preferred cover laminate. For example, the
barrier material layer thickness is preferably from about 0.4 to
about 6 microns, more preferably from about 1 to about 5 microns,
and more preferably from about 1 to about 3 microns in
thickness.
[0032] As noted, preferably the barrier material exhibits a
relatively low oxygen and/or water permeability. Most preferably,
the oxygen permeability is zero. A preferred maximum oxygen
permeability is approximately 50 cc/m.sup.2/24 hours. A preferred
maximum water permeability is approximately 50 cc/m.sup.2/24
hours.
[0033] For certain applications, it is contemplated that the
laminate of the present invention can be free of a barrier layer.
However, the preferred embodiment includes a barrier layer. Thus,
the barrier layer is described as being optional.
[0034] In certain applications, it may be preferred to utilize a
barrier material such as PVDC or metalized aluminum along an
outermost face of the filmic or outer layer. Without such barrier
layer, the oxygen transmission rate or water transmission rate will
be relatively high with respect to the outer face of one or more
layers in the laminate. As explained in greater detail herein,
after forming a cut or incision to an adhesive layer in the
laminate, barrier properties typically decrease along the cut
region. Thus, incorporation of a barrier material in the laminate
can improve barrier properties of the cut laminate.
[0035] Moreover if the present invention laminate and packaging
assembly is to be used for perishable products that require a
controlled atmosphere, an oxygen barrier layer is preferably used
at multiple locations within the laminate. For non-perishable
products there will likely be no need for such barrier.
[0036] Pressure Sensitive Adhesive Layer
[0037] The preferred multilayer laminate includes a pressure
sensitive adhesive (PSA) layer. The pressure sensitive adhesive
provides a tacky surface allowing a bond to another contacting
surface. Preferably, the properties of the pressure sensitive
adhesive are such that the bond also provides a seal to prevent or
at least significantly prevent the flow of air or other agents
across the region of the pressure sensitive adhesive.
[0038] A wide range of pressure sensitive adhesives can be used in
this layer so long as their properties and characteristics are
consistent with the packaging requirements of the resulting
assembly. The pressure sensitive adhesive could be a hot melt
pressure sensitive adhesive, such as for example a rubber-based or
acrylic-based pressure sensitive adhesive. The pressure sensitive
adhesive could be a UV cured hot melt. The pressure sensitive
adhesive could be based on a rubber-based hot melt composition, a
solvent rubber adhesive, a solvent acrylic adhesive, or a solvent
polyurethane adhesive. The pressure sensitive adhesive could be
emulsion-based such as an emulsion acrylic adhesive. As noted, a
wide array of pressure sensitive adhesives could be used. An
extensive selection of various pressure sensitive adhesives are
disclosed in U.S. Pat. Nos. 5,623,011; 5,830,571; and 6,147,165;
owned by the assignee of the present application.
[0039] A preferred pressure sensitive adhesive for use in the
pressure sensitive adhesive layer is commercially available under
the designation Fasson.RTM. S692N. The S692N adhesive is an acrylic
emulsion based adhesive. Generally, this adhesive is a polymeric
blend of butyl acrylate and 2-ethyl-hexyl acrylate monomers with
various tackifiers and processing acids. Other preferred pressure
sensitive adhesives include, but are not limited to, emulsion
acrylic adhesives and rubber-based hot melt adhesives.
[0040] The thickness of the pressure sensitive adhesive layer
typically ranges from about 12 to about 40 microns and preferably
from about 12 to about 20 microns. It will be understood however,
that the present invention includes laminates using thicknesses
greater than or lesser than these thicknesses for the pressure
sensitive adhesive layer.
[0041] Release Layer
[0042] The preferred multilayer laminate includes a release layer.
Preferably, the release layer is disposed immediately adjacent to
the pressure sensitive adhesive layer in the laminate. Most
preferably, the release layer is disposed between the pressure
sensitive adhesive layer and the inner sealing layer, and
preferably between the pressure sensitive adhesive layer and the
filmic layer. The release layer provides a release surface which,
as previously noted, is immediately adjacent to, and in contact
with, the pressure sensitive adhesive layer.
[0043] A wide variety of release materials such as those typically
used for pressure sensitive tapes and labels are known, including
silicones, alkyds, stearyl derivatives of vinyl polymers (such as
polyvinyl stearyl carbamate), stearate chromic chloride,
stearamides and the like. Fluorocarbon polymer coated release
liners are also known but are relatively expensive. A film skin
layer can be modified by adding one or more slip agent(s) including
a silicone type slip agent during the film co-extruding process.
The release layer can be provided by the slip agent modified film
skin layer. More particularly, the release layer can be in the form
of a silicone slip agent modified co-extruded polypropylene film
skin layer. For most pressure sensitive adhesive applications,
silicones are by far the most frequently used materials. Silicone
release coatings have easy release at both high and low peel rates,
making them suitable for a variety of production methods and
applications.
[0044] Known silicone release coating systems consist of a reactive
silicone polymer, e.g., an organopolysiloxane (often referred to as
a "polysiloxane," or simply, "siloxane"); a cross-linker; and a
catalyst. After being applied to the adjacent layer or other
substrate, the coating generally must be cured to cross-link the
silicone polymer chains, either thermally or radiatively (by, e.g.,
ultraviolet or electron beam irradiation).
[0045] Based on the manner in which they are applied, three basic
types of silicone release coatings used in the pressure sensitive
adhesive industry are known: solventborne, waterborne emulsions,
and solvent free coatings. Each type has advantages and
disadvantages. Solventborne silicone release coatings have been
used extensively but, because they employ a hydrocarbon solvent,
their use in recent years has tapered off due to increasingly
strict air pollution regulations, high energy requirements, and
high cost. Indeed, the energy requirements of solvent recovery or
incineration generally exceed that of the coating operation
itself.
[0046] Waterborne silicone emulsion release systems are as well
known as solvent systems, and have been used on a variety of
pressure sensitive products, including tapes, floor tiles, and
vinyl wall coverings. Their use has been limited, however, by
problems associated with applying them to paper substrates. Water
swells paper fibers, destroying the dimensional stability of the
release liner backing and causing sheet curling and subsequent
processing difficulties.
[0047] Solventless silicone release coatings have grown in recent
years and now represent a major segment of the silicone release
coating market. Like other silicone coatings, they must be cured
after being applied to the flexible liner substrate. Curing
produces a cross-linked film that resists penetration by the
pressure sensitive adhesive.
[0048] Informative descriptions of various release materials, their
characteristics, and incorporation in laminate assemblies are
provided in U.S. Pat. Nos. 5,728,469; 6,486,267; and US Published
Patent Application 2005/0074549, owned by the assignee of the
present application. It is also contemplated that various waxes
known in the art could be used for the release material or utilized
in the release layer.
[0049] The preferred laminates utilize release layers that are
relatively thin. For example, a typical release layer thickness is
from about 1 to about 4 microns. Preferably, the thickness of the
release layer is from about 1 to about 2 microns.
[0050] Filmic Layer
[0051] The preferred multilayer laminate includes a filmic layer or
inner substrate. The inner substrate provides support for the flap
and side wall laminate and particularly for the layers disposed
adjacent to the inner substrate. Representative materials for the
inner substrate include those noted herein for the outer substrate.
In addition, it may be preferred to utilize a co-extruded
biaxially-oriented polypropylene (BOPP) material. These materials
provide cost savings as they are relatively inexpensive, and they
have sufficient stiffness to dispense well and support out layer
resealing. Another preferred material for use in the inner
substrate layer is co-extruded biaxially-oriented polyethylene
terephthalate (BOPET). It is contemplated that oriented or
non-oriented versions of films could be used. The previously noted
PVC and OPA polymeric materials may also be suitable for use in
this layer.
[0052] The inner substrate thickness typically ranges from about 12
to about 60 microns, and preferably from about 12 to about 25
microns. The present invention includes the use of thicknesses
greater than or lesser than these thicknesses.
[0053] Sealing Layer
[0054] The preferred multilayer laminate includes a heat sealing
layer. Preferably, the heat sealing layer is disposed along the
underside or inner face of the laminate that contacts a
corresponding face of the container upon thermal bonding one
portion of the laminate to another portion of the laminate.
[0055] The heat sealing layer is a layer which is activated by heat
to allow the layer to bond to a plastic substrate. Materials for
the heat sealing layer include, but are not limited to, the
following film-forming materials used alone or in combination such
as polyethyelene, metallocene catalyzed polyolefins such as for
example copolymers of polypropylene (Co-PP) or terpolymers of
polypropylene (Ter-PP), syndiotactic polystyrene, syndiotactic
polypropylene, cyclic polyolefins, polyethylene methyl acrylic
acid, polyethylene ethyl acrylate, polyethylene methyl acrylate,
acrylonitrile butadiene styrene polymer, polyethylene vinyl
alcohol, polyethylene vinyl acetate, nylon, polybutylene,
polystyrene, polyurethane, polysulfone, polyvinylidene chloride,
polypropylene, polycarbonate, polymethyl pentene, styrene maleic
anhydride polymer, styrene acrylonitrile polymer, ionomers based on
sodium or zinc salts of ethylene/methacrylic acid, polymethyl
methacrylates, cellulosics, fluoroplastics, polyacrylonitriles, and
thermoplastic polyesters. Other contemplated materials for the heat
sealing layer include, but are not limited to, glycol-modified
polyethylene terephthalate (PETG), which is particularly well
suited for use when one or more other substrates are formed from
polyethylene terephthalate (PET). Preferably, PE is used in the
heat sealing layer, more preferably, a blend of PE and EVA, such as
for example, a blend of PE and EVA with special antiblock and
antistatic additives. A preferred material for use in the heat
sealing layer is glycol-modified polyethylene terephthalate (PETG).
Additional preferred materials for use in the heat sealing layer
include Co-PP or Ter-PP. A most preferred material for the heat
sealing layer is linear low density polyethylene (LLDPE).
[0056] The thickness of the heat sealing layer may vary according
to requirements of the packaging assembly. Typical thicknesses of
this layer are from about 15 to about 90 microns and preferably
from about 30 to about 60 microns. When utilizing a co-extruded
film skin layer, the skin layer is typically about 1.5 microns in
thickness.
[0057] The heat sealing layer is designed to be activated at
temperatures known to those skilled in the art. While the heat
sealing layer may activate at temperatures below those specified
for activation, the heat sealing layer is designed to activate at
certain temperatures based on the substrate material. Preferably,
the heat sealing layer activates at temperatures between about
90.degree. C. to about 160.degree. C., more preferably from about
100.degree. C. to about 150.degree. C., more preferably the heat
sealing layer activates at temperatures between about 110.degree.
C. to about 140.degree. C., and most preferably the heat sealing
layer activates at temperatures between about 120.degree. C. to
about 130.degree. C. Contact times are relatively fast, such as
from about 0.1 seconds to about 5 seconds, and typically about 2
seconds. Preferably, pressure is also applied to the respective
surfaces during heat sealing.
[0058] Cover Printing Layer
[0059] An optional printing layer may be disposed on the previously
described outer substrate. The printing layer serves to receive and
retain one or more inks deposited on the printing layer. The ink(s)
constitute indicia or other markings for the cover laminate and
package assembly. The printing layer can be formed from a wide
range of materials typically known to those skilled in the art. For
example, a variety of polyvinyl alcohol (PVA) and cellulose-based
materials can be used for the printing layer.
[0060] The printing layer typically ranges from about 3 to about 20
microns in thickness and preferably, from about 3 to about 8
microns in thickness.
[0061] Preferred Aspects of the Flap and Laminate Body or Side
Wall
[0062] Another significant feature of the preferred embodiment
laminate and resulting containers and packaging, is the provision
of one or more cuts, scores, or slits in certain layers. The cut,
score or slit can be formed in the laminate in a variety of ways,
however, a preferred method is to die cut the slit through
particular layers such as the sealing layer, inner substrate, and
release layer. In other layers, it is preferred to form the cut,
score or slit through the outer layer and the adhesive layer.
Preferably, these cuts are formed by die cutting. These aspects are
described in greater detail herein. This combination of cuts forms
the unique flap and sealing configuration.
[0063] It is also contemplated that by not forming the cut, score
or slit in select regions of the cover laminate, a hinge or
bridging portion for the flap can be provided. Thus, for example,
one or more cuts could be provided in a laminate along three of
four sides of a rectangular shaped pattern. The portion of the
laminate free of the cut would then serve as a hinge for the
resulting flap upon initial and later openings of the package.
[0064] Another reason for the preferred provision of the cuts,
scores or slits in the noted layer(s) of the cover laminate, is
that such cuts enable control of the contact surface area between
the pressure sensitive adhesive layer and the release layer. The
ability to readily control the amount, configuration, and shape of
the contact area enables direct control over the resealing strength
between the outer separable portion of the laminate and the inner
separable portion of the laminate. As will be appreciated, for
applications in which greater resealing strength is desired, the
contact area can be readily increased during design and/or
manufacturing. And for applications in which less resealing
strength is desired, the contact area can be easily reduced in
design and/or manufacturing.
[0065] Another preferred aspect of the preferred embodiment cover
laminate is that by appropriate selection of the materials that the
pressure sensitive adhesive contacts, i.e. the material layers
disposed immediately adjacent to the pressure sensitive adhesive in
the cover laminate, the surface energy of the exposed face of each
material layer can be tailored to provide desired sealing
characteristics such as particular resealing strengths. For
example, if a low resealing strength is desired, a release material
having a relatively low surface energy such as a silicone release
material could be used immediately adjacent to the pressure
sensitive adhesive layer. Furthermore, selection and arrangement of
appropriately engineered materials for use in the layers
immediately adjacent to the pressure sensitive adhesive could be
used to achieve differences in tack to ensure or at least promote,
retention of the adhesive with one layer as compared to another
layer. For example, by appropriate selection and use of materials
for the release layer and the layer disposed on an opposite face of
the pressure sensitive adhesive layer, retention of the adhesive
with the outer separable cover portion as opposed to remaining on
the inner cover portion bonded to the container can be
achieved.
[0066] Specifically, in accordance with the present invention, the
level of adhesion between the pressure sensitive adhesive and one
or more layer(s) immediately adjacent the adhesive, e.g. the
release layer, is controlled. The level of adhesion is preferably
controlled by (i) the use of a release layer disposed immediately
adjacent to the pressure sensitive adhesive layer and most
preferably disposed between the adhesive layer and the inner
substrate in the cover laminate; (ii) the configuration and surface
area of the release layer exposed after initial opening of the
cover; (iii) appropriate selection of release materials and/or
materials having desired surface energies used in the release
layer; (iv) appropriate selection of other materials in the cover
laminate, namely the pressure sensitive adhesive material and the
material of the layer disposed immediately adjacent the face of the
pressure sensitive adhesive opposite that of the release layer; (v)
the configuration and surface area of the pressure sensitive
adhesive material exposed after initial opening of the cover; and
(vi) the thickness of the pressure sensitive adhesive layer.
[0067] By controlling the level of adhesion, preferably by one or
more, or all of factors (i)-(vi), the pressure sensitive adhesive
layer can be more reliably retained with the outer separable
portion of the cover.
[0068] It is preferred that particular tack and peel
characteristics exist with regard to the pressure sensitive
adhesive and the layers disposed on opposite sides or faces of the
pressure sensitive adhesive layer. It is desirable that a
difference regarding these characteristics exists between the two
layers on opposite sides of the pressure sensitive adhesive layer.
Specifically, it is desired that a particular minimum difference
exists between the tack and peel characteristics associated with
(i) the pressure sensitive adhesive and the layer immediately
adjacent to one face of the adhesive, and (ii) the pressure
sensitive adhesive and the layer immediately adjacent to an
opposite face of the adhesive.
[0069] For a cover laminate utilizing a pressure sensitive adhesive
layer disposed between an inner substrate of co-extruded biaxially
oriented polypropylene (BOPP) and an outer substrate of
polyethylene terephthalate (PET), it is preferred that the
difference in tack and peel characteristics between these two
substrates and a respective face of the pressure sensitive
adhesive, be at least 1.5 N/in and preferably at least 3.0 N/in.
The greater adhesive bond preferably exists between the outer
substrate and a corresponding face of the pressure sensitive
adhesive as compared to the adhesive bond existing between the
inner substrate and an opposite face of the pressure sensitive
adhesive.
[0070] Appropriate selection of the pressure sensitive adhesive and
the release layer material primarily governs the force needed to
initially open a sealed container, and also the amount of force
necessary for subsequent opening operations after an initial
opening. This force, referred to as the "opening force," is the
force that a consumer must exert upon the cover in order to
separate the cover laminate into its respective portions and
thereby open the container. Typically, to provide a relatively easy
to open container, the opening force should be less than 10 N/in.
Also, it is desirable that some minimum force be necessary so as to
prevent unintended openings of the container. Thus, typically, a
minimum force of at least 1 N/in to about 2 N/in and preferably
greater than 3 N/in is targeted. For many applications, it is
preferred that a reseal force of from about 1 N/in to about 2 N/in
be provided.
[0071] Yet another preferred aspect is the provision of one or more
tabs that facilitate grasping and/or opening a flap. The tabs are
preferably formed during formation of an outer die cut, and extend
through several outer layers of the laminate such as the outer
layer and the pressure sensitive adhesive layer. The tabs may be in
a variety of different shapes depending upon the end use
requirements of the laminate and/or packaging assembly.
[0072] In the event that a tab is used in conjunction with a flap,
it is preferred to use an adhesive deadening material between the
underside of the flap and/or tab and the corresponding release
layer facing the flap and/or tab. A wide array of materials can be
used as the adhesive deadening material such as non-volatile
hydrocarbons and non-stick polymeric compounds. An example of such
a material is a non-toxic varnish or oily material.
[0073] A further preferred aspect of the resealable flaps and
laminates is the provision of one or more tamper identifiers. These
provisions provide a visual indication of whether the flap has been
previously opened. A preferred form of a tamper identifier is the
provision of one, two, or more small non-continuous uncut segments
within the die cuts, and particularly within an outer die cut as
explained herein. Upon initially opening the flap to gain access
into a package, the one or more non-continuous uncut segments are
severed or torn to thereby indicate occurrence of an initial
opening operation. Another preferred form of a tamper identifier is
the provision of one or more cut shapes within a reseal region of
the flap. Upon initially opening the flap, the cut shapes remain
with the body of the package and a corresponding number of
apertures result in the flap. These apertures and subsequent
mis-alignment between the cut shapes and the apertures provide
another indication of an initial flap opening having occurred.
[0074] By utilization of these key aspects, potentially with other
features of the preferred embodiment cover laminate as described
herein, very specific adhesion, resealing, and opening
characteristics of the cover laminate can be achieved. The
laminates and resealable flaps described herein can be used to form
an assortment of different resealable packages and containers.
[0075] Preferred Embodiment Assemblies
[0076] FIG. 1 illustrates a preferred embodiment resealable
packaging laminate 10 in accordance with the present invention. The
packaging laminate 10 comprises a laminate body 20 defining a
generally hollow interior (not shown) and an aperture 60 providing
access thereto. The laminate 10 also comprises a positionable flap
30 defining a proximal region 34 and a distal region 36. The
proximal region generally extends between a first proximal location
34a and a second proximal location 34b. The flap 30 is connected to
or otherwise affixed or secured to the body 20 of the laminate 10
along at least a portion of its proximal region 34. The flap 30 is
positionable such that the flap can be moved from an open position
such as depicted in FIG. 1, to a closed position in which the flap
30 covers the aperture 60 and preferably sealingly engages the
laminate body 20.
[0077] Preferably, the flap 30 defines a resealable region 32
extending about an outer periphery of the flap 30. That is, it is
preferred that the resealable region 32 extends along an underside
of the flap 30 from the first proximal location 34a to the distal
region 36 of the flap, and to the second proximal location 34b. As
explained in greater detail herein, preferably the resealable
region 32 includes exposed pressure sensitive adhesive. The
remaining region of the flap 30 exclusive of the flap resealable
region 32 is referred to herein as a flap remainder region 38 and
is described in greater detail herein.
[0078] The laminate body 20 defines a resealable region 62
extending about the aperture 60. As explained in greater detail
herein, preferably the resealable region 62 includes exposed
release material. The resealable region 62 is preferably shaped and
sized so as to correspond to the flap resealable region 32 of the
flap 30. It is also preferred that the laminate body resealable
region 62 is directed towards the flap resealable region 32. Thus,
upon closing the flap 30 and thereby covering the aperture 60, the
flap resealable region 32 is contacted with the resealable region
62 of the laminate body 20. Preferably, the extent of contact
between the resealable regions 32 and 62 is such that at least 80%,
more preferably at least 90%, more preferably at least 95%, and
most preferably at least 98% of the total surface area of the two
resealable regions 32 and 62 are in contact with one another. This
configuration promotes sealing and secure engagement between the
flap 30 and the laminate body 20.
[0079] A wide array of constructions and configurations may be
utilized for the flap 30. Preferably, the flap 30 includes an outer
flap portion 50 and an inner flap portion 40, which are preferably
secured or otherwise affixed to one another to form a unitary flap
or similar member. As depicted in FIG. 1, it is preferred that the
outer flap portion 50 be larger, i.e. have a larger surface area,
than the inner flap portion 40. Moreover, it is preferred that the
inner flap portion 40 be centrally located along an underside of
the outer flap portion 50. The remaining exposed underside of the
outer flap portion 50 extending about the inner flap portion 40 may
constitute the previously described resealable region 32 of the
flap 30. This resulting configuration provides a flap having a
reduced thickness about its outer edge, and an increased thickness
along interior regions.
[0080] For flaps comprising outer and inner flap portions 50 and
40, and particularly those that provide regions of differing
thickness as noted, it is preferred to form a region of reduced
thickness in the laminate body 20 extending about the aperture 60.
This region of reduced thickness can constitute the resealable
region 62 of the laminate body 20. Preferably, the sum of the
thickness of the laminate in the resealable region 62 and the
thickness of the outer flap portion 50 in the resealable region 32
is equal to the thickness of the flap 30 in the remainder region
38.
[0081] FIG. 2 is a partial cross sectional view of the resealable
packaging laminate 10 shown in FIG. 1. Specifically, the cross
section is taken across line 2-2 in FIG. 1 and so reveals a cross
section of the outer flap portion 50 and the inner flap portion 40,
and a corresponding configuration of the aperture 60 and the
resealable region 62 of the laminate body 20 extending about the
aperture 60. FIG. 2 also illustrates the flap 30 in position A and
closure of the flap 30 to position B to thereby cover the aperture
60. Upon positioning the flap 30 to its closed position designated
as position B in FIG. 2, it can be seen that the flap resealable
region 32 is contacted with the laminate body resealable region 62.
It will be appreciated that the flap 30 depicted in FIG. 2 may be
opened to a much greater extent than that shown in FIG. 2.
Furthermore, it will be appreciated that the flap 30 may, upon
being opened, exhibit an arcuate or curved shape as a result of the
flexible characteristic of the laminate.
[0082] FIG. 3 is an exploded schematic view of a preferred laminate
assembly 110 in accordance with the present invention. The
preferred assembly 110 comprises a plurality of layers which may be
arranged in a wide array of different orders and configurations.
However, an exemplary preferred arrangement is shown in FIG. 3. The
assembly 110 comprises an outer layer 120 defining an outer face
122, an adhesive layer 130, a release layer 140, a filmic layer
150, and an inner sealing layer 160. The inner sealing layer 160
defines an inner face 162. Preferably, the adhesive layer 130 is
disposed immediately adjacent to the release layer 140. One or more
barrier layers (not shown) can be incorporated in the laminate 110
alongside or between any of the layer(s) illustrated.
[0083] The plurality of layers 120, 130, 140, 150, and 160, and one
or more additional layers are preferably formed into a flexible
laminate that is used for the previously described packaging
laminate 10 and specifically, the flap 30 and laminate body 20
described in conjunction with FIGS. 1 and 2.
[0084] In accordance with the present invention, one or more cuts,
slits, or other incisions into the layers are formed to produce a
flap member. Preferably, the various cuts are formed in such a
manner to produce a flap with a resealable or reseal region and a
laminate body having a corresponding resealable or reseal region
for sealingly engaging the flap thereto. A preferred configuration
for such cuts is depicted in FIG. 3. Preferably, a cut, slit or
incision, generally referred to herein as a "die cut" and depicted
as 170 in FIG. 3 is formed in one or more outer layers such as the
outer layer 120 and the adhesive layer 130. Preferably, the die cut
170 in each of the layers 120 and 130 is of the same size, the same
shape and the same orientation. The die cut 170 is generally
referred to herein as an outer die cut. Preferably, another cut,
slit or incision, also referred to herein as a "die cut" and
depicted in FIG. 3 as 180, is formed in one or more inner layers
such as the release layer 140, the filmic layer 150, and the inner
sealing layer 160 as shown. Preferably, the die cut 180 in each of
the layers 140, 150, and 160 is of the same shape, the same size,
and the same orientation. The die cut 180 is generally referred to
herein as an inner die cut. Upon assembly of the layers, the die
cut 170 in the layers 120 and 130 forms an outer flap portion such
as the outer flap portion 50 depicted in FIGS. 1 and 2. And, the
die cut 180 in layers 140, 150, and 160 forms an inner flap portion
such as the inner flap portion 40 depicted in FIGS. 1 and 2.
[0085] It will be appreciated that the die cuts 170 and 180 may
each be in a variety of different forms besides the U-shaped
configurations depicted in FIG. 3. For example, die cuts that are
arcuate in shape may be used. Alternatively, poly-sided
non-rectangular shaped configurations may be used for the various
die cuts. It will be appreciated that the shape selected for the
outer die cut 170 will determine the shape of the resulting flap.
And, the shape selected for the inner die cut 180 will determine
the shape of the resulting aperture in the laminate.
[0086] FIG. 4 illustrates a preferred embodiment resealable bag
container 210 in accordance with the present invention. The bag
container 210 comprises a first end 220, a second end 230, and one
or more side walls 240 extending between the ends 220 and 230. The
ends 220 and 230 are preferably heat sealed to thereby form a
closed and sealed package or container. Defined in the side wall
240 is an aperture 260. A reseal region 262 extends about the
periphery of the aperture 260. The container 210 also comprises a
positionable flap 250 that includes a reseal region 252. As
depicted in FIG. 4, the flap reseal region 252 extends about the
outer periphery of the flap 250. As previously described herein, it
is preferred that the reseal regions 262 and 252 are similarly
sized, shaped, and configured so as to sealingly contact one
another upon closing the flap 250.
[0087] Referring further to FIG. 4, it is preferred that a region
of an adhesive, and preferably a pressure sensitive adhesive, is
exposed within the reseal region 252 of the flap 250. It is also
preferred that a region of a release material is exposed within the
reseal region 262 of the side wall 240. This configuration promotes
sealing engagement between the flap 250 and the side wall 240 upon
closing the flap 250 and covering the aperture 260.
[0088] FIGS. 5-10 illustrate additional features of the present
invention including for example various tabs for grasping flaps and
provisions for identifying that tampering or previous opening of
the flap from its adjacent side wall or laminate body has occurred.
FIGS. 5-10 each illustrates an outer die cut 370a, 370b, 370c,
370d, 370e, and 370f; and an inner die cut shown in dashed lines as
380a, 380b, 380c, 380d, 380e and 380f. These die cuts, as will be
understood, form flaps 330a, 330b, 330c, 330d, 330e, and 330f as
shown in FIGS. 5-10, respectively. One or more tabs 374, 376, and
378 may be provided for facilitating grasping of a flap. The one or
more tabs are formed as a result of forming the outer die cut. The
tabs are preferably located at or near a distal end of the flap.
The tabs may be in a variety of shapes such as, but not limited to
an arcuate shape, a triangular shape, or a rectangular shape, as
depicted in FIGS. 5, 7, and 8, respectively. It is also
contemplated that a tab which does not extend beyond the outer die
cut can be provided such as in FIG. 6.
[0089] Preferably, in accordance with another aspect of the present
invention, grasping of a tab can be further facilitated by
selective deposition of an effective amount of an adhesive
deadening material. Referring to FIGS. 5-10, it will be understood
that extending between the outer die cut and the inner die cut are
reseal regions. And, these reseal regions correspond to areas of
contact between an exposed region of a pressure sensitive adhesive
and an exposed region of a release material. Thus, by selective
placement of a region of adhesive deadening material within the
reseal region and proximate a tab of a flap, and between the
adhesive and the release material, the tab can be more easily
grasped and less affixed to the underlying surface. FIG. 5
illustrates a region 360a of an adhesive deadening material
deposited upon exposed release material within a reseal region
extending between the outer die cut 370a and the inner die cut
380a. The region 360a of deadening material is proximate the
arcuate tab 374 of the flap 330a. And, FIG. 6 illustrates a region
360b of an adhesive deadening material deposited upon exposed
release material within a reseal region extending between the outer
die cut 370b and the inner die cut 380b. The region 360b of
deadening material is proximate a tab resulting in the corner
region of the outer die cut 370b of the flap 330b. Similarly, FIG.
7 illustrates a region 360c of an adhesive deadening material
deposited upon exposed release material within a reseal region
extending between the outer die cut 370c and the inner die cut
380c. The region 360c of deadening material is proximate the
triangular tab 376 of the flap 330c. Likewise, FIG. 8 illustrates a
region 360d of an adhesive deadening material deposited upon
exposed release material within a reseal region extending between
the outer die cut 370d and the inner die cut 380d. The region 360d
of the deadening material is proximate the rectangular tab 378 of
the flap 330d.
[0090] The present invention also provides tamper identification
provisions that indicate whether a flap has been initially opened.
These provisions are in the form of one or more non-continuous die
cut segments. These small non-continuous die cut segments extend
between adjacent die cuts and are initially in the form of uncut or
otherwise integral material in the associated layers. Upon
initially opening a flap from its corresponding body or side wall,
the small non-continuous die cut segments tear, rupture, or
otherwise separate generally along a line extending between
adjacent neighboring die cuts. Thus, torn or severed non-continuous
die cut segments indicate that the flap has previously been
initially opened.
[0091] FIGS. 5, 7, and 8 depict representative tamper identifiers
in the form of non-continuous die cut segments. Referring to FIG.
5, non-continuous die cut segments 372a separate the arcuate die
cut forming tab 374 from the remaining portions of outer die cut
370a. As will be understood, upon initially opening the flap 330a,
the tab 374 resulting from the arcuate segment is grasped and
pulled. This operation results in rupture of the segments 372a.
FIG. 7 depicts non-continuous segments 372c separating the
triangular die cut segment forming tab 376 from the outer die cut
370c. And FIG. 8 illustrates non-continuous segments 372d
separating the rectangular die cut segment forming tab 378 from the
outer die cut 370d.
[0092] The present invention also provides tamper identification
provisions in the form of one or more die cut "islands" located
within the reseal region extending between the outer die cut and
the inner die cut. The islands are die cut through the thickness of
a flap, and preferably in the area of reduced thickness in the flap
reseal region. These tamper die cuts preferably extend through an
outer layer and an adhesive layer. The tamper die cuts may also
extend through a release layer. The tamper identifying islands may
be provided in any number, shape, and area within a reseal region.
FIG. 6 illustrates three tamper identifiers 350a in the form of
ovals and generally oriented at an acute angle to one or more sides
of the outer die cut 370b. FIG. 7 illustrates two tamper
identifiers 350b in the form of rectangles located in the reseal
region. FIG. 9 depicts three oval-shaped tamper identifiers 350c.
And, FIG. 10 illustrates three circular tamper identifiers 350d
located in a reseal region. It will be understood that the island
tamper identifiers function by providing a visual indication that
the corresponding flap has been previously opened. Once the flap is
opened, the die cut islands remain in a flap receiving area of the
body or side wall. Upon closing the flap, it is virtually
impossible to align the resulting apertures in the flap with the
projecting islands, and also nearly impossible to insert the
islands into each of their corresponding apertures in the flap.
These aspects are described in greater detail in conjunction with
FIG. 11.
[0093] FIG. 11 schematically illustrates the laminate assembly 110
shown in exploded fashion in FIG. 3, after formation into a
laminate body 114 and a flap 190 attached thereto. Referring to
FIG. 11, the flap 190 includes the outer layer 120 and the adhesive
layer 130. A portion of adhesive is exposed within the flap reseal
region 192 extending about the outer periphery of the flap 190. The
layers 120 and 130 generally correspond to an outer flap portion as
previously described. The flap 190 further comprises a release
layer 140, a filmic layer 150, and a sealing layer 160. The layers
140, 150, and 160 are preferably centrally located along the
underside of the flap 190. The layers 140, 150, and 160 generally
correspond to the inner flap portion described herein. It will be
understood, by further reference to FIG. 3, that the shape of the
outer flap portion is dictated by the shape of the outer die cut
170; and that the shape of the inner flap portion is dictated by
the shape of the inner die cut 180.
[0094] The flap 190 may also be provided with an arcuate shaped tab
374. Preferably, the tab is located at a distal end of the flap
190. The flap 190 may also define one or more apertures 352
resulting from die cutting corresponding tamper identifying islands
350, and opening the flap 190.
[0095] The laminate body 114 also comprises the outer layer 120,
the adhesive layer 130, the release layer 140, the filmic layer
150, and the sealing layer 160. An aperture 182 is defined in the
laminate body 114 and results from the inner die cut 180 best shown
in FIG. 3. A reseal region 184 extends about the aperture 182 and
generally between the outer die cut 170 and the inner die cut 180.
A portion of the release layer 140 is exposed within the reseal
region 184. An effective amount of an adhesive deadening material
360 is located in the reseal region 184 and preferably at a
location corresponding to the tab 374 upon closing the flap 190.
The laminate body 114 also includes a plurality of tamper
identifier islands 350, as previously described herein.
[0096] The present invention also provides a method for opening and
resealing a previously thermally sealed package. The method
comprises separating a first portion of the laminate, i.e. the flap
from a remaining second portion of the laminate. This results in
separation of the pressure sensitive adhesive layer from the
release layer in the noted resealable region(s) to thereby expose a
region of the pressure sensitive adhesive and a corresponding
region of the release layer. As laminate separation does not occur
elsewhere, the package is readily opened and the interior of the
container becomes accessible. The method also comprises matingly
contacting the exposed region of pressure sensitive adhesive to the
exposed region of the release layer, to thereby reseal the package.
The term "matingly contacting" refers to positioning the flap
having the exposed region of pressure sensitive adhesive, such that
this region is aligned with the corresponding exposed region of
release layer in the remaining laminate portion. Preferably, upon
matingly contacting these regions to another, the entirety of each
region is contacted with the other, or very nearly so.
[0097] Select regions of the laminate are thermally adhered to one
another by contacting a first region of sealing layer of the
laminate to another region of the laminate and preferably to
another region of the sealing layer of the laminate. The method
also includes heating the sealing layer to a temperature of from
about 120.degree. C. to about 130.degree. C. for a time period of
at least 2 seconds.
[0098] The preferred laminates are formed by appropriate
arrangement and desired ordering of layers. Generally, a collection
of one or more outer layers such as the outer layer and the
pressure sensitive adhesive layer are applied to one another. An
outer die cut is then formed in this collection of layers. If one
or more tabs and/or non-continuous uncut tamper identifiers are to
be provided, the outer die cut pattern is appropriately configured
as described herein to provide such provisions. In addition, if one
or more island type tamper identifiers are used, these are cut or
otherwise formed in the outer layers as described herein.
Concurrently or separately, a collection of one or more inner
layers such as the inner sealing layer, a filmic layer, and a
release layer are applied to one another. An inner die cut is then
formed in this collection of layers. The two sets of layers are
then applied together such that the pressure sensitive layer is
contacted with the release layer, while ensuring proper alignment
occurs between corresponding outer and inner die cuts. In the event
that an amount of adhesive deadening material is to be used, that
material is appropriately deposited in a reseal region defined
between the outer and inner die cuts.
[0099] A flexible wall container or package can be formed from the
laminate described herein by forming a relatively long and
continuous tube of the previously described laminate. Preferably,
this is accomplished by heat sealing a longitudinal edge of the
sealing layer to an opposite longitudinal edge of the sealing
layer. One end, i.e. the "bottom" of the resulting bag, is then
heat sealed. The contents of the bag are then added and then the
other end, i.e. the "top" of the bag, is then heat sealed.
[0100] The present invention includes the provision of multiple
flaps in a single package or container. This configuration may be
preferred for containers having partitioned interiors.
[0101] Many other benefits will no doubt become apparent from
future application and development of this technology.
[0102] All patents, published applications, test methods or
standards, and articles noted herein are hereby incorporated by
reference in their entirety.
[0103] As described hereinabove, the present invention solves many
problems associated with previous type devices. However, it will be
appreciated that various changes in the details, materials and
arrangements of parts, which have been herein described and
illustrated in order to explain the nature of the invention, may be
made by those skilled in the art without departing from the
principle and scope of the invention, as expressed in the appended
claims.
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