The present application relates to packages formed from flexible sheet materials, such as bags, pouches, and the like. The application relates more particularly to such packages that have easy-open functionality as well as reseal capability.
One such package that is in widespread use is the zipper bag, which is essentially a plastic bag having three permanently closed edges and a fourth open edge at which a zipper or profiled-strip closure is attached. In some cases the bag can also include a permanent end seal adjacent the zipper, and may include a notch and score line to allow the end seal to be torn off the bag so that the zipper can be opened to gain access to the bag's contents.
There are significant drawbacks to zippers. For example, a zipper is a separate component from the bag itself, and thus represents added material cost. Furthermore, incorporating the zippers into the bag production process results in added complexity and slows down the process, and therefore is detrimental to productivity and manufacturing cost. Zippers are also notoriously difficult to reclose, which frustrates users of the bags. Moreover, it is necessary to space the zipper from the end of the bag so that there remains a sufficient amount of the two bag walls for the user to grasp in order to open the zipper, and this represents wasted material. A further problem when the bag has an end seal that is torn off, however, is that sometimes the tear does not occur along the desired line, but instead results in the remaining parts of the bag walls being partially or completely torn off right up to the zipper, which further exacerbates the non-user-friendliness of the zipper.
The present disclosure relates to an easy-open resealable package such as a bag or pouch, formed from a flexible laminate. The laminate includes an inner structure adhesively laminated to an outer structure. The inner and outer structures are coextensive with each other, meaning that their respective edges substantially coincide with one another (i.e., the outer structure is not a label applied to only a portion of the exterior of the package, but is an integral part of the package itself). An opening feature is formed in the laminate and is operable for forming an opening into an interior of the package. Various types of opening features are described herein.
The package includes a region of pressure-sensitive adhesive disposed between the inner and outer structures proximate the opening feature. One or more lines of weakness are formed in the outer structure so as to form at least one peel strip as an integral portion of the outer structure. The at least one peel strip is separable from the remainder of the outer structure along the line(s) of weakness. The at least one peel strip is positioned such that peeling off the at least one peel strip exposes the region of pressure-sensitive adhesive, which remains on the inner structure. Access into the interior of the package can be had through the opening formed by operating the opening feature, and the package can be resealed by folding down an end portion of the package and adhering the end portion to the pressure-sensitive adhesive so as to substantially close the opening.
As noted, various opening features are possible. In one embodiment, the opening feature comprises a score line formed in the inner structure. The score line is positioned such that the at least one peel strip covers it. To open the package, the at least one peel strip is peeled off to expose the score line, which allows access to the package interior through the opening formed by the score line. Optionally, the region of pressure-sensitive adhesive can be on both sides of the score line, so that the end portion of the package that is folded down carries pressure-sensitive adhesive that is adhered to the pressure-sensitive adhesive on the opposite side of the score line, to create an adhesive-to-adhesive bond for reclose. Alternatively, the region of pressure-sensitive adhesive can be only on the opposite side of the score line from the end portion, such that the end portion is simply adhered to the pressure-sensitive adhesive to reclose the package.
In other embodiments, the package can include an end seal spaced from the region of pressure-sensitive adhesive, and the opening feature can be a line of weakening located between the end seal and the pressure-sensitive adhesive region, which allows the end seal to be torn off the package for gaining access to the package interior. The package is reclosed by folding down the end portion of the package and adhering it to the pressure-sensitive adhesive. The line of weakening for tearing off the end seal can be a laser score line. The package can include a notch in one edge intersecting the laser score line, to assist in tearing off the end seal. The edge having the notch can comprise a side seal.
In embodiments where the package includes a score line in the inner structure for opening the package, there can be two separate peel strips. An opening peel strip is formed by a first line of weakness in the outer structure and a separate reclose peel strip is formed by a separate, second line of weakness in the outer structure. The opening peel strip is positioned such that peeling it off exposes the score line in the inner structure, and the reclose peel strip is positioned such that peeling it off exposes the region of pressure-sensitive adhesive.
Alternatively, there can be a single peel strip that covers both the score line in the inner structure as well as the region of pressure-sensitive adhesive. The peel strip is peeled off to gain entry into the package, and then the end portion is folded down and adhered to the pressure-sensitive adhesive to reclose the package.
Whether there is a single peel strip or two separate opening/reclose peel strips, the/each peel strip can include a tab portion that is free of any adhesive attachment to the inner structure underlying the tab portion, whereby the tab portion is readily graspable for initiating peeling of the/each peel strip from the package.
In any of the various embodiments, the inner structure can include a surface treatment to enhance adhesion to the pressure-sensitive adhesive relative to the outer structure, so as to ensure that the pressure-sensitive adhesive remains adhered to the inner structure and the at least one peel strip peels cleanly off the pressure-sensitive adhesive. The surface treatment can be, for example, a primer on the inner structure. Additionally or alternatively, the outer structure can have a surface that is treated to reduce adhesion to the pressure-sensitive adhesive relative to the inner structure. The particular treatments used are not critical, as long as the result is that the peel strip(s) will cleanly peel off and leave the pressure-sensitive adhesive on the underlying inner structure.
In some embodiments, the inner and outer structures are adhesively joined to each other by two different adhesives. Pressure-sensitive adhesive is pattern-printed on one of the structures (preferably, the inner structure) in a region that will be covered by the peel strip. Outside of this region, a permanent laminating adhesive is pattern-printed on the remaining part of the surface of the structure such that the permanent adhesive does not cover the pressure-sensitive adhesive. The two structures are then laminated to each other via these adhesives. The resulting laminate is then subjected to precision scoring operations to form a score line in the inner structure (for those embodiments in which there is such a score line), and to form the line(s) of weakness in the outer structure defining the peel strip(s). The score line in the inner structure can be formed either mechanically (e.g., by die-cutting) or with a laser. Likewise, the line(s) of weakness in the outer structure can be formed mechanically or by laser. The score line and line(s) of weakness are accurately located to be in registration with the region of pressure-sensitive adhesive. The completed laminate can then be converted into a package by any of the known processes such as vertical form/fill/seal, horizontal form/fill/seal, etc.
Having thus described the present disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which some but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
The laminate 30 comprises an inner structure 31 adhesively laminated to an outer structure 32. The inner structure can comprise one or more layers of flexible material. In the illustrative example shown particularly in
The outer structure 33 can comprise one or more layers of flexible material. In the illustrative example of
The inner and outer structures are laminated to each other by permanent laminating adhesive 50 and pressure-sensitive adhesive 52 that are located in particular regions between the structures. Specifically, the permanent adhesive 50 is pattern-printed by any suitable technique onto nearly the entire surface of the inner structure 31 that will be joined to the outer structure 32, except for a relatively small, defined region in which the pressure-sensitive adhesive 52 is pattern-printed onto the inner structure, as further described below. The two structures are then laminated together via the adhesives.
The package 20 has integral opening and reseal features that are built into the laminate 30, as opposed to being formed by separate components (e.g., zippers, labels, tapes, etc.) that are applied to the packaging material. The opening feature in the package 20 comprises a score line 40 formed in the inner structure 31. The score line 40 advantageously extends entirely or substantially entirely through the thickness of the inner structure 31 so that the inner structure can be easily severed along the score line to form an opening therethrough. The opening feature further includes a peel strip 36 that is an integral part of the outer structure 32 of the package. The peel strip 36 is formed by a line of weakness 42 formed entirely or substantially entirely through the thickness of the outer structure 32 so that the peel strip 36 delineated by the line of weakness 42 is easily separable from the remainder of the outer structure. The line of weakness follows a generally U-shaped path in the illustrative embodiment, and the peel strip defined by the line of weakness extends substantially fully across the width of the package, but the invention is not limited to any particular size or shape of peel strip.
The pressure-sensitive adhesive 52 is confined to a region at least as extensive as the region underlying the peel strip 36. The margins of the pressure-sensitive adhesive region can be somewhat outward of the edges of the peel strip, in order to ensure that there is no permanent adhesive attaching the peel strip 36 to the underlying inner structure 31. In this way, the peel strip 36 can be peeled easily from the inner structure so as to expose the underlying pressure-sensitive adhesive 52 that remains on the inner structure 31, and also to expose the score line 40 of the opening feature. To facilitate grasping the peel strip 36, the peel strip includes a tab portion 38 that overlies a corresponding region 39 (
The reclose feature of the package 20 comprises the region of pressure-sensitive adhesive 52 that is exposed by the removal of the peel strip 36. In this embodiment, the pressure-sensitive adhesive 52 covers a region that is on both sides of the score line 40, i.e., there is pressure-sensitive adhesive below the score line and there is also pressure-sensitive adhesive above the score line on an end portion 26 of the package that includes the top end seal 22.
Operation of the package 20 is now described with reference to
When only part of the contents have been consumed, the user may wish to reseal the package to retain the remaining contents. To reseal the package, the user folds down the end portion 26 of the package along a fold line generally coincident with the score line 40 (see
It should be noted that the line of weakness 42 defining the peel strip 36 can be configured so that the peel strip is not completely removable from the package but instead remains attached at the end opposite from the end having the tab portion 38. In this case, the peel strip is moved out of the way to allow the end portion 26 of the package to be folded down to reseal the package. Alternatively, the line of weakness 42 can be a closed loop so that the peel strip can be completely removed from the package.
The package 20 provides distinct advantages over packages that employ zippers, labels, tapes, or the like, for resealing purposes. No additional components are required apart from the packaging laminate itself. Fabrication of the laminate 30 can be done at high speed in a continuous web process generally as described in applicant's copending U.S. patent application Ser. No. 11/098,872, the entire disclosure of which is hereby incorporated herein by reference. The laminate can then be converted into packages and filled at high speed, using any of the known processes and equipment, in the same manner that similar non-resealable packages are made. Furthermore, the package is simpler to operate than packages having cumbersome zippers or tapes for resealing.
The process for constructing the laminate 30, as noted, is generally similar to that described in the copending '872 application. Continuous webs of the inner structure 31 and outer structure 32 can be prepared in advance and stored in large rolls. Construction of the laminate 30 begins by pattern-printing the permanent adhesive 50 and pressure-sensitive adhesive 52 onto one of the structures (preferably, the inner structure 31), in repeating patterns along the length of the advancing structure. The inner structure 31 is then laminated to the outer structure 32. Next, the resulting laminate is advanced to a scoring station at which the score line 40 is formed in the inner structure 31 and the line of weakness 42 is formed in the outer structure 32, in registration with the adhesive patterns. The score line and line of weakness can be formed either mechanically (e.g., by die-cutting) or by laser. That is, one can be formed mechanically and the other by laser, or both can be formed mechanically or by laser.
The package 20 described above is advantageous in many respects. However, the invention is not limited to packages having such a configuration. A second embodiment of the invention is now explained with reference to
Operation of the package 120 is as follows. To open the package for the first time, the user grasps the tab portion 138 of the opening peel strip 136 and pulls generally in the widthwise direction of the package to peel the peel strip off the package as shown in
When only part of the contents have been consumed, the user may wish to reseal the package to retain the remaining contents. To reseal the package, the user peels off the reclose peel strip 136′ to expose the pressure-sensitive adhesive 152′ (
An advantage of the package 120 over the previous embodiment is that the pressure-sensitive adhesive 152′ remains covered by the reclose peel strip 136′ while contents are being removed from the package, and thus it does not become fouled by bits of the contents, which could reduce its tackiness. When it is desired to reseal the package, the reclose peel strip is removed, exposing fresh pressure-sensitive adhesive 152′. However, both regions of pressure-sensitive adhesive can be involved in resealing the package.
A package 220 in accordance with a third embodiment of the invention is now explained by reference to
To open the package 220, the user tears off the end 225 of the package above the score line 228, as shown in
The package 220 includes a peel strip 236 covering a region of pressure-sensitive adhesive 252, similar to the previous embodiments. To reseal the package, the user peels off the peel strip 236 (
As apparent from the foregoing description of various embodiments of the invention, the pressure-sensitive adhesive 52, 152′, 252 used for reclose purposes must remain on the inner structure 31 of the laminate when the overlying peel strip is peeled off to expose the adhesive. This can be ensured by controlling the surface characteristics of the inner and outer structures in direct contact with the pressure-sensitive adhesive, using any of various techniques. For example, there is a rough rule of thumb that an adhesive will generally remain attached to the surface on which it is originally applied, as opposed to another surface that is subsequently adhered to the adhesive. Thus, it is advantageous to apply the pressure-sensitive adhesive to the inner structure during manufacturing of the laminate 30. Additionally, it is advantageous to treat the surface of the inner structure to enhance its affinity for adhering to the pressure-sensitive adhesive. This can be done in various ways. One approach is to first apply a primer material to the inner structure, and then to pattern-print the pressure-sensitive adhesive onto the primer material. The primer material can be any of various compositions, depending on the formulation of the pressure-sensitive adhesive. It is also possible to treat the surfaces of both the inner and outer structures in such a way that the inner structure has a significantly greater affinity for adhering to the pressure-sensitive adhesive. The invention is not limited to any particular treatment of the surfaces.
One exemplary structure for the laminate 30 is now described with reference again to
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.