This disclosure relates to food or beverage containers in the form of a sealed pouch or the like formed from flexible laminate material. The laminate typically includes at least a barrier layer and a sealant layer. Edges of the laminate material are sealed together via the sealant layer to create the pouch or other configuration.
A variety of food and non-food products are packaged using flexible packaging materials formed primarily of laminations of one or more of polymer films, metallized polymer films, paper, metal foil, and the like. In many instances, it is desirable to provide easy access to the contents of the package such that a user can provide minimal effort to open the package without the risk of injury. Packages that are easily opened, however, typically suffer from being poorly sealed resulting in the contents of the package being adversely affected (e.g., becoming soggy, drying out, etc.) by exposure to the surrounding environment.
Easy opening of such flexible packaging has been a longstanding problem to which much effort has been devoted toward developing a satisfactory solution by many workers in the field. Mechanical or laser ablation to form a notch or line of weakening in the laminate material, at which tearing of the material can be initiated, has been the typical approach. In the case of laser-formed opening features, a past approach has been to ablate partway through the thickness of the laminate to weaken it while attempting to not compromise the barrier function of the laminate. These techniques have not met with complete success in all cases, particularly when the unablated portions of the laminate are a highly extensible material, because the extensible layers may not tear easily. Instead, the highly extensible materials typically stretch, and thus, result in opening failures of the package.
Further, mechanical processes to form a notch or line of weakening in the laminate material add complexity and scrap to the manufacturing process. The equipment involved with mechanical processes, such as die-cutting equipment, typically involves numerous moving parts. Manufacturing processes involving moving parts typically malfunction more frequently and become misaligned, and thus, additional maintenance of the manufacturing process is required to repair and/or align the moving parts. Mechanical processes also can create scrap that may interfere with the manufacturing process or may need to be removed by a separate process, adding cost and complexity to the overall manufacturing process.
Accordingly, there is a need for an improved manufacturing process to produce opening features for sealed pouches formed from flexible laminate that securely seals the contents of a package during the packing process but allows the package to be easily opened by the consumer.
The present disclosure addresses the above needs and achieves other advantages, by providing a flexible packaging structure and method for making same, in which the structure has opening features built into the structure. In accordance with one embodiment of the invention, a pouch is formed from a laminate comprising an outer structure joined in face-to-face relation to an inner structure. The outer structure forms the exterior surface of the completed pouch, and the inner structure forms an interior product-contacting surface of the pouch. After the laminate is wrapped and/or folded into a generally tubular configuration, opposite longitudinal edge portions of the laminate are sealed together to form a fin, and opposite ends of the tubular structure are sealed to form top and bottom seal areas. The pouch includes easy-open tear-facilitating features located within the top seal area.
In accordance with an embodiment of the invention, the tear-facilitating features include a tear initiation feature comprising a hole formed through the laminate and straddling a first fold line along which the laminate is folded when it is wrapped about the longitudinal axis. There is a second fold line along which the laminate is folded when it is wrapped. The fold lines respectively become the two longitudinal edges of the completed pouch. The tear initiation feature is located within the top seal of the completed pouch.
The laminate further defines a fin tear-propagating feature comprising two tear areas formed respectively in the side edges of the laminate such that the tear areas substantially coincide on the fin so as to form the fin tear-propagating feature. The fin tear-propagating feature is substantially in transverse alignment with the tear initiation feature. The tear areas can comprise notches formed into the side edges of the laminate so that they extend partway across the widths of the respective fin panels that are sealed together to form the fin.
The top seal is configured such that the tear initiation feature and fin tear-propagating feature are located in the top seal area, so that these features do not compromise the sealing of the pouch. The top seal is further configured so that a portion of the unsealed area of the laminate is in transverse alignment with the tear features. In this manner, when a user opens the pouch by starting the tear at the tear initiation feature and continuing to tear transversely across the pouch, the tear will intersect the unsealed area so as to gain access to the contents through the opening that results.
The tear initiation and fin tear-propagating features are the only tear features in the pouch. There are no further score lines or any other features promoting or facilitating tearing of the laminate material.
In yet another embodiment of the invention, the laminate does not include a tear initiation feature comprising a hole formed through the laminate and straddling a fold line. Instead, the laminate includes a score line that extends across the laminate in the transverse direction. Where the laminate is formed of an outer structure laminated to an inner structure, the score line is formed in the outer structure but not in the inner structure.
There is a second fold line along which the laminate is folded when it is wrapped. The two fold lines respectively become the two longitudinal edges of the completed pouch. One end of the score line is located within the top seal of the completed pouch.
The laminate further defines a fin tear-propagating feature comprising two tear areas formed respectively in the side edges of the laminate such that the tear areas substantially coincide on the fin so as to form the fin tear-propagating feature. The fin tear-propagating feature is substantially in transverse alignment with the score line. The tear areas can comprise notches formed into the side edges of the laminate so that they extend partway across the widths of the respective fin panels that are sealed together to form the fin.
The top seal is configured such that the fin tear-propagating feature is located in the top seal area so that it does not compromise the sealing of the pouch. One end portion of the score line is also located in the top seal area. The top seal is further configured so that a portion of the unsealed area of the laminate contains an opposite end portion of the score line. In this manner, when a user opens the pouch by starting the tear at one end of the score line and continuing to tear transversely across the pouch, guided by the score line, the tear will intersect the unsealed area so as to gain access to the contents through the opening that results.
Having thus described the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments of the invention 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.
As an initial overview of preferred embodiments of the invention, a flexible packaging laminate is constructed to have a built-in opening feature. The laminate is constructed as a multi-layer structure by adhesively laminating a first structure to a second structure, wherein each of the first and second structures comprise one or more layers of flexible material. Adhesive may be applied to one of the structures before lamination. Once the laminate is formed, laser ablation operations are performed along portions of the laminate using a laser to penetrate through at least a portion of a thickness of the laminate material. Laser ablation of the tear areas of the laminate preferably begins at the center of a tear area, and progressively the laser moves in a direction radially outwardly from the center until the laser delineates the desired outer perimeter of the tear area. The laser ablation process may also be used to form a score line. Further, laser ablation may also be used to form a sealant reduction area along the second structure of the laminate by, for example, ablating an area of the second structure of the laminate. The second structure of the laminate may be a sealant film.
More particularly, with reference to
Prior to printing the first structure in the print station, the surface of the first structure that is subsequently laminated to the other structure can be treated by a corona discharge or flame treatment apparatus 16 to render the surface more receptive to the inks and/or to render the surface more readily bondable to the adhesive that is subsequently applied to the surface as described below. Alternatively, the first structure 10 can have already been so treated prior to being wound into the supply roll 12, such that the treatment apparatus 16 is unnecessary.
Following the optional corona/flame treatment and/or optional printing operation, and with reference to
The first structure 10 is then advanced to a laminating station 40, comprising a pair of rolls forming a nip therebetween. The first structure 10 is passed through the nip along with a second structure 42 that is advanced from its own supply roll 44, and the first and second structures 10, 42 are laminated to each other. The second structure 42 comprises one or more layers of flexible material, and is coextensive with the first structure 10—i.e., the width of the second structure 42 is substantially equal to the width of the first structure 10 and the longitudinal edges of the second structure 42 substantially coincide with the longitudinal edges of the first structure 10.
The laminate may also optionally include a metallization layer or a metal foil layer between the first structure 10 and the second structure 42. This is beneficial in enhancing the barrier performance of the laminate as already noted. Additionally, however, where a metal foil layer is included, it can also be helpful when a laser is used for ablating only the first structure 10 or the second structure 42. For example, it can be difficult to employ a sufficiently high laser energy to ablate through a polyethylene sealant layer without ablating through the laminate more deeply than desired. Thus, the metal foil layer can be helpful in “tuning” the laser to penetrate only up to the foil layer. However, when a metallization layer is employed instead of a metal foil layer, the metallization layer generally will not stop a laser beam. In that case, the laser can be “tuned” to score to a certain depth by using different polymers for the different layers in the laminate, such that, for example, one layer readily absorbs laser energy and thus is relatively easily ablated, while a layer below that layer is formed of a polymer that does not absorb laser energy as well and hence is not ablated.
The resulting laminate 46 is then advanced to a reel-up (not shown) where it is wound into a roll for subsequent processing in the second phase of the manufacturing process as described below. Alternatively, it is possible for the reel-up operation to be omitted, such that the laminate is directly advanced to the second phase.
With reference to
Next, the laminate is advanced to an optional second ablation station 60 that can comprise a laser 64 and sensor 66. The operation of the laser 64 is synchronized with the advancement of the laminate in a manner as described above.
As an alternative to the use of lasers for ablation of the laminate, ablation of the laminate 46 may be accomplished by cutting or chemical removal. For instance, as depicted in
Additionally, it is within the scope of the invention to ablate one side of the laminate via laser and to cut or otherwise mechanically or chemically ablate the other side. This can be advantageous, for example, when one of the structures making up the laminate is readily ablated by the particular wavelength of laser radiation employed, but the other structure is not as readily ablated. For instance, when the first structure 10 is a polyester such as PET, it can readily be ablated with a CO2 laser of a particular wavelength, but if a polyethylene heat seal layer is employed for the second structure 42, that layer is not as readily ablated by the CO2 laser as is the PET. In this case, kiss cutting or other mechanical process can be used to ablate the second structure 42.
After the ablation operations, the laminate 46 can be sent to a reel-up (not shown) and wound into a roll for subsequent processing. The laminate can also be slit into a plurality of partial widths and wound into multiple rolls. In this latter instance, each partial width would have the recurring patterns of adhesives applied with suitably configured adhesive applicators to the full-width material, and would have the recurring ablated areas formed by suitably configured ablation devices acting on either the full-width laminate prior to slitting or acting on each partial-width portion after slitting.
Some possible applications for the resulting laminate are now explained with reference to
As illustrated in
The tear areas 78, 79 of the laminate are preferably positioned along the junction 93 between the front panel 82 and the second-visible rear panel 88 in an abutting relationship. The shape of the tear areas 78, 79 may be substantially semi-circular or parabolic segments with respect to the junction 93. Together, tear areas 78, 79, when abutting each other, may form a substantially circular area on the laminate portion 70. A center area formed between the combination of the abutting tear areas 78, 79 may be offset in a perpendicular direction from the junction 93 existing between tear areas 78, 79.
The sealant reduction areas 80 are positioned in the top seal portion 76 of the laminate portion 70. In a preferred embodiment, sealant reduction areas 80 are located in the top seal portion 76 of the front panel 82, the first-visible rear panel 84, and the interior fin panel 92. The sealant reduction areas 80 of the preferred embodiment are also positioned adjacent to one or both of tear areas 78, 79. The sealant reduction areas 80 are also preferably positioned along a path that the laminate portion will be torn by a user of the flexible package 94.
Formation of the first tear area 78, second tear area 79, and sealant reduction areas 80 may be accomplished through the use of a laser ablation process discussed above. By performing laser ablation on a surface of the laminate portion 70, a laser can be configured to penetrate through either a portion or the full thickness of the laminate portion 70. Ablation of a tear area of the laminate portion 70 preferably begins at a center of the area to be ablated and progressively moves the laser in a direction radially outwardly from the center of the tear area. The use of such a technique helps in reducing the amount of scrap material from the laminate portion 70 that may be produced during the ablation process. Ablation of the laminate portion 70 may also include the formation of a score line adjacent to the tear areas 78, 79. Such a score line is preferably oriented in a tearing direction and adjacent the tear areas 76, 78.
When the flexible package 94 is opened, a tear is created in the flexible package 94 at the groove formed by the tear areas 76, 78 as illustrated in
The laminate defines a tear initiation feature 112 comprising a hole formed through the laminate and straddling a first fold line 114 along which the laminate is folded when it is wrapped about the longitudinal axis. There is a second fold line 116 along which the laminate is folded when it is wrapped. The fold lines 114 and 116 respectively become the two longitudinal edges 118 and 120 of the completed pouch, as shown in
The laminate further defines a fin tear-propagating feature 122 comprising two tear areas 124 and 126 formed respectively in the side edges 104 and 106 of the laminate such that the tear areas substantially coincide on the fin 108 so as to form the fin tear-propagating feature 122. The fin tear-propagating feature 122 is substantially in transverse alignment with the tear initiation feature 112. In the illustrated embodiment, the tear areas 124 and 126 comprise notches formed into the side edges of the laminate so that they extend partway across the widths of the respective fin panels that are sealed together to form the fin 108.
As depicted in
In the embodiment of
Yet another embodiment of the invention is depicted in
The laminate 200 differs from the laminate 100 with respect to the type of tear initiation feature employed. Specifically, the laminate 200 does not include a tear initiation feature comprising a hole formed through the laminate and straddling the fold line 214. Instead, the laminate 200 includes a score line 212 that extends across the laminate in the transverse direction. Where the laminate is formed of an outer structure laminated to an inner structure (similar to the structures 10 and 42 illustrated in
There is a second fold line 216 along which the laminate is folded when it is wrapped. The fold lines 214 and 216 respectively become the two longitudinal edges 218 and 220 of the completed pouch, as shown in
The laminate further defines a fin tear-propagating feature 222 comprising two tear areas 224 and 226 formed respectively in the side edges 204 and 206 of the laminate such that the tear areas substantially coincide on the fin 208 so as to form the fin tear-propagating feature 222. The fin tear-propagating feature 222 is substantially in transverse alignment with the score line 212. In the illustrated embodiment, the tear areas 224 and 226 comprise notches formed into the side edges of the laminate so that they extend partway across the widths of the respective fin panels that are sealed together to form the fin 208.
As depicted in
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.
The present application is a continuation-in-part of application Ser. No. 12/180,709 filed on Jul. 28, 2008, which is currently pending, and the entire disclosure of which is hereby incorporated herein by reference.
Number | Date | Country | |
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Parent | 12180709 | Jul 2008 | US |
Child | 13040645 | US |