This disclosure relates generally to flexible packaging and, in particular, to flexible packaging having a reclosable opening.
Flexible packaging is well known in the art for use in containing food products. Flexible films can provide a lightweight package with a substantially hermetic seal for shipping and storage of a variety of food products, including, for example, crackers, chewing gum, chocolate, cookies, cheese, sandwiches, biscuits, candy, meat products, and dried fruits and vegetables. Some of these flexible film packages also may contain structural supports, such as a frame or tray.
One example of such flexible film packages are flow-wrap type packages, which may employ a continuous film or web to envelop a product during assembly or formation of the package. Flow-wrap packages may include, for example, horizontal or vertical fin seal or lap seal packages, end seal wrap, horizontal bagging and pillow-pouch packaging. In one configuration, flow-wrap packaging positions a film, such as polyethylene or polypropylene, adjacent a product, wraps the film around the product, forms a seal from the ends or edges of the film, and then forms seals at either end of the product. These seals may be permanent and also may provide some structural integrity. Flexible film packages have other advantages. For example, they can be manufactured at substantially lower cost than rigid containers, are lightweight (resulting in lower transportation costs), and can reduce space required for storage.
Despite the advantages of flexible film, these packages are sometimes difficult for consumers to open. Further, these packages often contain various amount of food product, and a consumer may not want to consume all of the food product at one time. Therefore, a reclose feature may be included to provide users with an easy, efficient manner of preserving some of the food product for a later time. The reclose feature may provide a partial barrier to moisture and gas resulting in a partially hermetic seal, though it may not provide a complete hermetic seal, and may help to retain the shelf-life or freshness of a food product contained within the package.
The flexible packages that have a resealable or reclosure feature are sometimes difficult to manufacture on equipment that is widely available. For example, some flexible film packages may require specialized die assemblies or heat seal bars to produce the seals, package openings, and other package features related to the reclose feature. Another drawback with the manufacture of some flexible packages is the common requirement of precisely calibrated manufacturing equipment. For example, packages and processes that employ a pattern-applied adhesive may require specialized equipment that may need to be properly calibrated. As another example, some laminate structures may employ partial depth die cuts from both the interior and exterior surface of the laminate structure, which increases the complexity of the equipment. These processes also may require very precise registration of the package elements to ensure the consumer is able to easily and reliably open the package and also to ensure proper closure or sealing of the flexible package.
In addition, previous package designs also tend to require additional package material to accommodate the equipment and various manufacture and consumer specifications. This extra film or other material (such as a label backing) often resulted in costly waste, which increases the cost of the packages.
Pursuant to the various embodiments described herein, flexible film packages and methods of producing such packages are provided herein. The flexible film packages may have at least a partial, initial seal against ambient atmosphere and are easily openable and reclosable. More particularly, the initial seal, which is present prior to initial opening of the flexible film package, may provide at least a partial barrier against ambient atmosphere, including gas and moisture, for an extended period of time. For example, the initial seal of the flexible film package may provide a light barrier and also a gas and moisture barrier for at least 6 to 8 months prior to initial opening. In some applications, a gas and moisture barrier may be desired for even longer periods of time prior to initial opening. Further, the flexible film packages are generally resealable such that the shelf-life of food products contained therein is not unnecessarily shortened due to exposure to the ambient atmosphere once the flexible film package is initially opened. Thus, the flexible film packages may have a reseal feature that provides a resealable seal that is present subsequent to initial opening of the package. While the present disclosure is described for food product applications, it also can be applied to non-food, medical, pharmaceutical, industrial packaging applications and the like.
In one approach, the flexible film package is generally configured to accommodate multiple servings of a food product. Thus, the resealing characteristics of the flexible film package help retain freshness or shelf-life of the food product remaining within the package subsequent to initial opening. The seals of the flexible film package, such as any longitudinal seals including, for example, a fin or lap seal, and any ends seals may be hermetic (and also may have varying degrees of hermeticity, such as partial or substantial hermetic seals) to help retain the shelf-life of any food products contained therein. The seals may be formed by a variety of process such as, for example, hot seal, cold seal, low tack seal such as that employing a low tack adhesive or fastener, sonic waves, and combinations thereof. Any resealable seals of the flexible package, such as that formed around the package opening, may be formed, in part, by a pressure sensitive adhesive located between the flexible film and an the elongated closure layer. This resealable seal feature may be formed by a variety of manufacturing processes.
The flexible film packages may have a variety of configurations, including, for example, a bag, a pouch, or other shapes such as a cylindrical-shape, a column-shape, or a rectilinear-shape, among others. For example, the flexible film package may have squared edges such as that found on a primarily rectilinear-shaped package, or may have more curvilinear-shaped edges, such as that found on more circular or ovoid-shaped packages. Further, the flexible film package may be formed around the food product, such as a package having a sleeve configuration that is wrapped around a discrete stack or stacks of food products. In other applications, the flexible film packages may be fully or partially formed and then filled with the food products, which may be helpful for various discrete food products. The various configurations may be easily opened and resealed while maintaining package integrity.
By one approach, the flexible film has two opposing edge portions that meet to form a longitudinal seal extending from a first end seal to a second end seal. The flexible film may have a score that defines a package opening upon initial rupture or initial opening. In one illustrative embodiment, an elongated closure layer extends over the score and extends from the first end seal (or to the first package end) to the second end seal (or second package end) and within the opposing edge portions that meet to form the longitudinal seal. A pressure sensitive adhesive may be located between the flexible film and the elongated closure layer. The elongated closure layer may have a tack-free gripping portion used to release at least a portion of the elongated closure from the flexible film to form the package opening.
By one approach, the package configuration and shape may be primarily influenced by the products contained within the package, in part, due to the flexibility of the laminate film. In another configuration, the flexible film may be configured as a flow-wrap or overwrap around a support structure, such as an internal rigid support or product tray.
The method for producing the flexible film packages provided herein may include forming a score in a portion of a continuous web of flexible film having a longitudinal axis and applying a continuous closure layer along the longitudinal axis with a pressure sensitive adhesive. By one approach, the continuous closure layer may be applied over a partial width of the continuous web of flexible film. The method also may include forming a continuous longitudinal seal from two opposing edges of the continuous web of flexible material and forming a first end seal and a second end seal. In one approach, an adhesive-free grasping portion may be formed at a first end of the flexible package. As discussed below, the flexible package material may be converted into one package blank off-line or in-line with the packaging processes and also may be formed in both horizontal and vertical form-fill-seal operations, among others.
A method of packaging products in a series of packages may include feeding a continuous film web having longitudinal edges and a predetermined width between the longitudinal edges. The method also may include merging a continuous substrate with the continuous film web across less than the entire predetermined width. By one approach, the continuous film web is scored to define an opening in the film web upon initial opening once the substrate is removed from the continuous film web and an adhesive, such as a pressure sensitive adhesive that provides a degree of releasability and resealablity, is provided between the continuous substrate and the continuous film web. If performed in-line, the method may provide products in a series for packaging, and the continuous film web and substrate may be wrapped around the products. Further, a longitudinal seal, such as a fin or lap seal, may be provided along the longitudinal edges of the continuous film web, and leading and trailing end seals may be provided between adjacent packages of the series of packages.
In one configuration, the method of manufacturing resealable flexible film packages includes scoring a continuous film to define an opening in a subsequently formed individual package; applying a continuous pressure sensitive adhesive label or closure layer to at least cover the score; feeding the film/label combination around the product to envelop the product; forming a longitudinal seal by joining the opposite edges of the film together; forming two substantially transverse end seals; and scoring peel tabs in a unsealed film area distal to an end seals.
The series of flexible packages may be formed in-line just before the film is being wrapped around a product or may be formed off-line well before the products are packaged. For example, a laminate structure may be prepared prior to being brought to the packaging line to fill the packages with products. In another configuration, the laminate may be formed in-line with the packaging operation such that the laminate is formed around or just before the product is packaged.
As used herein, the flexible film may be a formed of a thin polymer material. For example, the flexible film may be a flexible sheet of material in a roll or as individual blanks. To form the flexible film, a variety of processes may be employed. The flexible film may be, for example, laminated, extruded, cast, blown, or a combination thereof. By one approach, the flexible film may include a laminate having several thin layers of material. The laminate structure may include a polyethylene terephthalate (PET) layer and/or an oriented polypropylene (OPP) layer. Other optional laminate layers include a polyethylene (PE) layer, a polypropylene (PP) layer, a polylactic acid (PLA) layer, a sealant layer, an ink or print layer, nylon, and a metalized layer, such as a metalized oriented polypropylene (MET OPP) layer, to note but a few options. These different layers may have a variety of thicknesses and densities. Furthermore, the flexible film may be a combination of several of the above-mentioned film structures. By another approach, the flexible film may include a single layer (mono-web) polymer. If a single layer polymer is employed, the film may include, for example, polyethylene terephthalate, polyethylene, nylon, or oriented polypropylene. By yet another approach, the flexible film also may include a mono-web with a sealant thereon. Further, the components of the flexible film laminate may be joined by adhesives or by extrusion processes.
If a PET layer is used in the flexible film laminate, the PET layer may impact the rigidity of the laminate. More particularly, the PET layer may have different degrees of stiffness from flexible to semi-rigid, depending on the thickness of the PET layer. A PET layer may be incorporated into the laminate because it is relatively lightweight and strong and can have a high transparency if desired. The PET layer also may be useful as an oxygen (gas) and moisture barrier. In addition, an OPP layer also may further strengthen the flexible film and also provide a useful barrier to permeability.
The flexible film package may include a score that defines a package opening upon initial rupture or initial opening. The term “score” as used herein may describe any type of mechanically-formed or cut score line, a laser-formed score, or any other scoring means that would compromise the integrity of the film (i.e., a line or area of weakness). A score may be disposed partially through the depth of the flexible film, or it may be a die cut through the entire depth of the film. The score also may be formed on either side of the flexible film such that the score may be cut into the exterior or interior surface of the flexible film. In one example, the score is made into the flexible film from the interior surface of the flexible film and extends through the flexible film and substantially through the pressure sensitive adhesive. In addition, the score also may be a discontinuous line such as a set of perforations, which also may be either partially through the depth of the flexible film or completely through the entire depth of the flexible film.
By one approach, the elongated closure layer is disposed or continuously applied upon the flexible film over the score such that there are generally no disruptions in the elongated closure layer or portions where the flexible film lacks the elongated closure layer along one axis of the film. The elongated closure layer may comprise a label such as a label with a backing, a release liner or a linerless label. In another configuration, the elongated closure layer may include a second flexible film with pressure sensitive adhesive disposed between the flexible film and the second flexible film. As discussed below, the pressure sensitive adhesive may be an interstitial layer to a laminated film structure such that the pressure sensitive adhesive is laminated between the flexible film and the second flexible film layers.
In yet another configuration, the elongated closure layer may comprise a tape that is continuously applied over the flexible film along its longitudinal axis. Though a linerless label may be similar to tape, a linerless label oftentimes requires additional printing, including, for example, for registration purposes. As illustrated below, the elongated closure layer may be applied on both horizontal and vertically formed packages. The continuous closure layer may be transparent, opaque, or optionally printed. The continuous closure layer may include any of a variety of flexible or semi-rigid polymers, such as, for example, an oriented polypropylene (OPP), including a bi-axial OPP, and a polyethylene terephthalate (PET) layer. In one illustrative embodiment, the continuous closure layer may have a thickness of about 0.5 to 5.0 mil (50 to 500 gauge; 0.0127 to 0.127 mm). By one approach, the continuous closure layer may be about 1.0 to 3.0 mil (100 to 300 gauge; 0.0254 to 0.0762 mm) in thickness. In one configuration, the continuous closure layer may have a thickness of about 2.5 mil (250 gauge; 0.0635 mm). For some applications, PET may be desirable because of its thermal resistance in creating non-peelable seals. Further, while the elongated closure layer may be a continuous strip of material continuously applied to the flexible film without disruption, it is noted that in some configurations, the label may be more of a discrete-type label, as described below in other embodiments.
The continuous closure layer may be applied to cover at least the score line. Further, the continuous closure layer preferably extends beyond the score line to provide sufficient marginal region around the score to effectively reseal the package opening once the score has been initially opened or ruptured.
As suggested, the package opening is preferably resealable such that at least a partial hermetic seal is obtained around the opening (in some configurations the resealable opening is substantially hermetic). The pressure sensitive adhesive between the flexible film and the elongated closure layer helps produce the resealing characteristics of the package opening. The pressure sensitive adhesive is preferably neutral or non-reactive to the product to be packaged. By one approach, the pressure sensitive adhesive may include, for example, a cold formed adhesive, a hot melt adhesive, a cold seal adhesive, a natural or synthetic latex adhesive, a low tack adhesive, ethylene vinyl acetate (EVA), an acrylic adhesive (such as a water-based or solvent acrylic adhesive), a styrene block copolymer adhesive, a butyl rubber adhesive, a silicone rubber adhesive, a natural rubber adhesive, a nitriles adhesive, an acrylic emulsion adhesive, and combinations thereof. Further, the pressure sensitive adhesive may be extruded, coextruded, printed, or combinations thereof. In one configuration, the pressure sensitive adhesive is an acrylic water-based adhesive. The pressure sensitive adhesive may be a variety of thicknesses. By one approach, the pressure sensitive adhesive may be about 0.5 to 1.5 mil (50 to 150 gauge; 0.0127 to 0.0381 mm) in thickness. The pressure sensitive adhesive may be suitable for resealing in a variety of conditions, such as ambient and refrigerated conditions, to note but a few.
In some configurations, the pressure sensitive adhesive may provide a substantially hermetic seal even under refrigerated conditions (i.e., the pressure sensitive adhesive can be operable in a temperature range of about −10 to 90 degrees Celsius; and preferably in the range of about 2 to 7 degrees Celsius). The pressure sensitive adhesive may be applied directly to the film but also may be applied to ink or another coating on the film. By one approach, the pressure sensitive adhesive remains attached to the continuous closure layer, even after the closure layer is repeatedly opened and reclosed. In another configuration, the pressure sensitive adhesive is a low tack adhesive or fastener. Optional low tack adhesives or fasteners are disclosed in U.S. patent application Ser. No. 13/035,399, filed Feb. 25, 2011, which is incorporated herein by reference. The low tack adhesive may include a variety of suitable materials exhibiting a relatively low tack to undesired surfaces but, at the same time, still exhibits a good bond strength to desired surfaces (such as not delaminating from the flexible film), and a relatively good cohesive or self adhesive bond strength to like surfaces to hold a flexible package or pouch closed, but still permit the package to be openable or peelable by hand. If a low tack adhesive is employed with the package, it is anticipated that the pressure sensitive adhesive may be adhered to either the closure layer, the film, or both, once the closure layer is pulled upward or away from the film and the package is open. In one illustrative embodiment, a portion of the low tack adhesive (PSA) remains adhered to the film and another portion of the low tack adhesive (PSA) remains adhered to the continuous closure layer during opening of the package.
In addition, the initial seal of the package (prior to opening) also may be substantially hermetic (e.g., provide a gas and moisture barrier) for extended periods of time. The initial seal may be created by the package end seals or longitudinal seal, along with the continuous closure layer and pressure sensitive adhesive laminated above the score, which subsequently defines a package opening.
In one configuration, a resealable flexible film package includes a scored film with edges that are longitudinally sealed to form a sleeve. A first package or sleeve end seal is disposed substantially transverse to the longitudinal seal at a first package end. A second package or sleeve end seal is disposed substantially transverse to the longitudinal seal at a second package end. In some configurations, the first and second end seals can be optionally peelable or non-peelable. As used herein, a peelable seal is one where the sealant layers may separate from one another, and a non-peelable seal includes a sealant that bonds such that the sealant layers do not separate, i.e., a destructive seal. The film between the first and second end seals defines a package interior. The flexible film has a label or other continuous closure layer continuously disposed over the score of the film and along a longitudinal axis of the package with a pressure sensitive adhesive. The label can be employed to reclose or reseal the package as contents are removed from the package. In addition, after removal of some of the package contents, the film may be rolled or twisted to compress the package, and then, the label may be applied thereover to reclose or reseal the package. The package size may then be rolled or twisted to reduce the package size to the amount of content remaining in the package.
By one approach, the pressure sensitive adhesive has a peel strength between the film and the label that is greater than a force required to separate sides of the score. The label may extend beyond the score line sufficiently enough to reseal the package with the pressure sensitive adhesive disposed between the label and the film. A wide variety of score patterns are anticipated, and several configurations are provided herein. A score may be disposed generally longitudinally from the first package end to the second package end. In addition, the score may be straight, arcuate, or a combination thereof. Further, the score may include shapes such as a “T” shape, a teardrop, and a circle, to note but a few. In one configuration, the score may define an opening at or near the first package end. In some embodiments, the score line forms a loop between the end seals. In other embodiments, the score may begin at an outer edge of the first end seal and extend rearward, joining to form a single score line. In one configuration, the score line does not extend past the second end seal. In yet another configuration, the score may extend into and/or through the end seals. Since the seal area may be formed by heat seal bars, the heat employed to form an end or longitudinal seal in the package, also may melt the polymers sufficiently to inhibit any tearing of the score past the heat seal, even if the score extends into the heat seal area prior to forming of the seal.
The terminus of the score line adjacent the second package end may be configured to inhibit or prevent further tearing of the film beyond the score line. The end of the score line adjacent the second package end may include configurations having a “J” hook, a double “J” hook, a smile, a shepherd's hook, a teardrop, and a double teardrop (providing a relatively large package opening at either end of the package), among others. In one example, the score line includes an opening, such as a teardrop-shaped opening, adjacent the first package end that extends to a single score line running generally longitudinally toward the second package end, which provides an opening to the package interior. In another configuration, the score includes an opening, such as a teardrop-shaped opening, adjacent the first package end and two generally straight portions extending therefrom and extending longitudinally down the package. The generally straight portions may be parallel and may be spaced about 5 mm or less apart. The score also may include a narrow arcuate section joining the two generally straight portions adjacent the second end. In one configuration, the label extends beyond the first end seal and at least to the leading edge of the package.
As discussed below, a second score line or area such as a tab score may be added to the package to define a tab portion such as a tab in the film/label laminate. This second score line or area may be disposed distal and adjacent to the first sleeve end seal. In addition, multiple second score lines or a score area can be added to assist with proper functioning of the tab portion. The multiple score lines can be added to assist with concerns regarding variations in the registration of the elements.
Referring initially to
More specifically, the score 16 is formed into the flexible film 12 and may define the package opening 36 once the flexible film package 5 (
In addition to the score 16 that subsequently forms the package opening 36 (
In one illustrative embodiment, the score 16 and the tab score 15 are formed after the continuous closure layer 14 is applied to the flexible film web 12. In such a configuration, the score 16 may extend through the entire depth of the flexible film 12 and possibly through portions of the pressure sensitive adhesive 18. It also is anticipated that the score 16 may extend slightly into the continuous closure layer 14; however, the score 16 does not extend into the continuous closure layer 14 sufficiently enough to compromise the integrity of the barrier properties of the continuous closure layer 14. A variety of different score depths also are anticipated for tab score 15 as well.
A pre-scored film (or one scored prior application of the closure layer) also can define tear lines to create an opening on the flow-wrap package as the label is pulled back. The score 16 may maintain the seal of the flexible film package prior to opening, such that the flexible film 12 is not completely scored through the entire depth. Alternatively, the score 16 may extend through the flexible film 12 such that the continuous closure layer 14 substantially provides the seal prior to initial opening of the flexible package.
A variety of score 16 configurations are anticipated and a few examples are discussed herein. The particular score configuration employed for a given flexible film package may depend on the products being packaged, whether a structural support is being incorporated into the flexible film package, and the manufacturing equipment available, among other factors, By one approach, the score 16 defines a package opening that permits access to at least 70 percent of the products within the flexible film package upon initial opening of the package. More particularly, when the elongated closure layer 14 is peeled to the end of the score 16 to expose the entire score 16, it is anticipated that a user may access (i.e., remove from the package) any of at least 70% of the product within the package. This gives the consumer access to a substantial portion of the products within the flexible film package just after initial opening. By yet another approach, the score 16 defines a package opening that permits access to at least 90% of the product within the package. In another configuration, the score 16 defines a package opening permitting access to at least 50% of the product within the package.
Referring briefly to
Flexible film web 12, 112, as suggested above, may be a laminate with several layers of material, including, for example, a PET layer, an OPP layer, a PE layer, a MET OPP layer, a PP layer, and/or a PLA layer, to note a few options. These layers may be joined by adhesives or by an extrusion process. Alternatively, the flexible film web 12 may be a single layer polymer or mono-web. Since the flexible film package is at least partially hermetically sealed, the flexible film web preferably provides a gas and moisture barrier. By one approach, the flexible film may be about 1 mil to about 5 mil (100 to 500 gauge; 0.0254 to 0.127 mm) in thickness. By another approach, such as that employed with extrusion lamination, the flexible film web 12 may be about 0.47 mil to about 0.98 mil (47 to 98 gauge; 0.012 mm to 0.025 mm) in thickness. In one illustrative embodiment employed with extrusion lamination, the flexible film web 12 may be about 0.67 mil to about 0.71 mil (67 to 71 gauge; 0.017 mm to 0.018 mm) in thickness. For the above extrusion lamination examples, the extrudate also will add about 0.4 mil to about 1.2 mil (40 to 120 gauge; 0.01 to 0.03 mm) of additional thickness to the flexible film. The thickness of the film may be a function of the desired barrier to gas, moisture, and light, along with the level of desired structural integrity, the desired depth of score line, and the available manufacturing equipment.
Flexible film web 12, 112 may be a heat sealable copolymer. In some configurations, the heat sealable polymer forms a seal between, for example, 50 and 300 degrees Celsius. Flexible film web 12 also may be a pressure sealing film. In one configuration, the film web 12, 112 may be a pressure sealing film. For example, the pressure sealing film may form a seal between, for example, a pressure of about 0.7 to 7.0 kg/cm. By one approach, the pressure sealing film forms a seal at about 5.6 kg/cm.
In addition to the various laminate layers mentioned above, additional laminate layers such as sealants, stiffeners, ink, release layers, also may be incorporated into the laminate structure. For example, a sealant layer can be added to facilitate the formation of seals that enclose the product. By one approach, the sealant layer may be oriented on the film surface directed to the interior of the package (interior-facing surface). The sealant layer may be a variety of polymer sealants, such as a heat activated polymer sealant layer like ethylene vinyl acetate (EVA), ionomer plastic (such as that sold under the trade name SURLYN by DuPont), metallocene, and organoclay, among others. In one example, seals, such as fin seals, can be formed using a heat activated sealant layer. In addition, cold sealant and pressure sealants also may be used with the configurations disclosed herein. If the products within the flexible film package are food products, then it is noted that food grade sealants would be employed.
In one configuration, stiffeners are added to flexible film 12, 112 to increase the stiffness of the film. These stiffeners may be in addition to the stiffness adjustments that can be made by changing the thicknesses or densities of the previously mentioned laminate layers. These stiffeners can be added as a component of the extruded film or as a separate layer. For example, a laminate layer such as a polyamide polymer (e.g., nylon) may be included in the laminate film structure of flexible film web 12. By one approach, nylon may be added as a laminate layer that is held to the remainder of the film structure by an adhesive. Further, in one configuration, the nylon layer may be positioned in between other layers such that the other flexible film layers are attached on each side of the nylon layer (i.e., a tie layer). In one configuration, a film structure, such as a 2 mil structure, may include a nylon layer of about 6-10% of the film thickness or about 0.003 to 0.005 mm. In one approach, the nylon layer comprises about 8% of the film thickness. By yet another approach, the nylon layer may comprise about 0.004 mm.
As noted, an ink layer may be formed into the laminate as an additional laminate layer. For example, one specific laminate can include ink and a primer disposed between other film layers such as a PET layer and an OPP layer. Alternatively, the ink may be a surface printed layer with a release over-lacquer such as that used for a mono-web. Other additional layers may include a metalized layer, as noted above.
A release layer may be incorporated in some configurations to provide more flexibility in the laminate structure and also may increase the numbers options for pressure sensitive adhesives. For example, if a release layer is incorporated, the pressure sensitive adhesive used in the packager may have a lower peel force. The release layer may be a homo-polymer such as an OPP. By one approach, a release layer also may be an over-lacquer that is printed or extruded onto the film thereby providing a barrier between the pressure sensitive adhesive and the flexible film to provide consistent opening characteristics.
By one approach, the elongated closure layer 14 is continuously applied along the flexible film 12 such that the continuous closure layer 14 extends from one end seal to another end seal once the flexible film package 5 is formed. In
The elongated closure layer 14, which is adhered to the flexible film 12 and covers score 16, permits easy manual opening of the flexible package 5. In one embodiment, the elongated closure layer 14 can be formed such that the flexible package 5 has a tab portion 40. More particularly, a tab portion 40 (
In one configuration, flexible film 12 has a first edge portion 20 and a second edge portion 22. The edge portions 20, 22 may be brought together and formed into a longitudinal seal, such as, fin seal 24 extending from a first end seal 26 to a second end seal 28, as shown in
In addition,
In one illustrative approach, the end portions of the flexible film of two packages disposed adjacent the first and second end seals 26, 28 are not sealed together. The free ends 46, since they are not sealed together, may be graspable by a user. Thus, to open a package, especially those lacking a resealable closure, a user may grasp the free ends of the flexible film that are adjacent the upper and lower portions of the end seal and pull apart the end seal. More particularly, in some packages, the free end portions are the pulled apart by consumers to rupture the substantially hermetic film-to-film seal that forms the end seal, sometimes referred to as a destructive seal. In other configurations, including those lacking free end portions, a user may elect to pull the front and back panels (or the upper and lower panels) away from one another, adjacent the seal, to rupture the end seal. Both of these manners of opening a package, rupture the permanent or primary seal and are oftentimes not resealable.
The end seals 26, 28 and the longitudinal seal 24 are film-to-film seals and may be considered primary seals and are oftentimes permanent or destructive seals. The closure layer 14 also forms a seal with the flexible package 5 and may be considered a secondary seal. The secondary seal is resealable and generally is not destructive. In one illustrative embodiment, the peel force required to separate the primary seals (primary peel force) is higher than the peel force required to separate the secondary seals (secondary peel force).
In one example, the flexible film package 5 has primary seals, including end seals 26, 28 and longitudinal seal 24, along with a secondary seal formed by the closure layer 14 over the length of the flexible film package 5. The secondary seal is formed, in part, by the pressure sensitive adhesive 18 disposed between the continuous closure layer 14 and the flexible film 12.
As suggested above, many consumers previously opened packages by rupturing the primary seals at the end or top of a package. As illustrated in
As noted above, the free ends 46 of the package are adjacent the end seals but are generally not sealed together. More particularly, the free ends 46 of the package may be found in an unsealed area of the film laminate and, by one approach, are distal to the end seal of the package thereby allowing a user to grasp and peel open a portion 38 of the upper layer or portion 48 of the film and the continuous closure layer 14.
As noted above, the tab portion 40 may be formed by the combination of the tab score 15 and the separation cut 44. The leading end of the flexible film package 5 may be defined by the separation cut 44, which also may be adjacent the location of the tab portion 40. In one illustrative approach, a user may grasp at that end to begin opening the package. Specifically, a consumer may grasp the free end 46 of the upper portion 48 of the flexible film 12 and also the portion of the continuous closure layer 14 adjacent the leading end. To assist the user with lifting or peeling the continuous closure layer 14 from the flexible film 12, one of the free ends 46 adjacent the upper portion 48 of the end seal 26 may have tab score 15 formed therein. Thus, a portion of the flexible film 38 may separate from the remainder of the flexible film 12 at one of the tab scores 15. The portion 38 may cover the pressure sensitive adhesive 18 disposed underneath the continuous closure layer 14 and provide the user with a tack free gripping or tab portion 40. More particularly, the portion 38 is provided by having the tab score 15 separate the flexible film portion 38 from the remainder of the flexible film 12.
A cut-out 52, shown in
The separation cut 44, which defines the leading edge of the tab portion 40 and the leading edge of the flexible film package 5, also defines the trailing edge of another flexible film package 5. Thus, as a leading flexible film package 5 is provided a trailing edge by a die or knife cutting assembly, a trailing flexible film package 5 is provided a leading edge.
The pressure sensitive adhesive 18, which is disposed or applied between the flexible film 12 and the elongated closure layer 14, may have a variety of strengths and compositions. As noted above, the pressure sensitive adhesive may include, for example, a cold formed adhesive, a hot melt adhesive, a cold seal adhesive, a natural or synthetic latex adhesive, a low tack adhesive, ethylene vinyl acetate (EVA), an acrylic adhesive (such as a water-based or solvent acrylic adhesive), a styrene block copolymer adhesive, a butyl rubber adhesive, a silicone rubber adhesive, a natural rubber adhesive, a nitriles adhesive, an acrylic emulsion adhesive, and combinations thereof. Further, the pressure sensitive adhesive may be extruded, coextruded, printed, or combinations thereof. By one approach, the pressure sensitive adhesive has a higher bonding strength than the strength required to tear or separate the score 15. In such a configuration, a user may pull upward on the elongated closure layer 14, expose the package opening, remove the desired amount of product, and then reseal the package using the pressure sensitive adhesive outside the score. By one approach, the pressure sensitive adhesives may have a variety of thicknesses. For example, the pressure sensitive adhesive could be between about 0.2 mils to 1 mil thick and may be even thicker.
Referring now to
A series 310a of flexible film packages, illustrated in
Another illustrative series of flexible film package blanks 410 is shown in
In addition to the score 416, a tab score 415 is formed in flexible film 412. The tab score 415 (illustrated in
The tab portion 440 also has a removed portion 438 from the flexible film 412 that covers the pressure sensitive adhesive 418 disposed on the continuous closure layer 414. As illustrated in
In addition to a configuration with a longitudinal seal and two end seals, it also is anticipated that the flexible film package may have three side seals. By one approach, such a package may have a dead fold.
As illustrated in
Turning to
The package 1305 further includes notches 1386 through the flexible film 1312 adjacent a tab portion 1340 that is adjacent the first edge 1360. The notches 1386 help remove a portion 1338 of the flexible film 1312 from the remainder of the film. As shown in
Another package configuration is illustrated in
The package 805 shown in
In addition, the package 805 includes a top fold 821 and bottom fold 823. The top fold 821 may be formed in the flexible film 812 and the continuous closure layer 814. In addition, a score 816 is formed in the flexible film 812 to create a package opening 836 (
As shown in
Another illustrative series of flexible film package blanks 610 is shown in
The series of flexible film package blanks 610, which has a continuous flexible film 612 and a continuous closure layer 614, is formed into individual packages 605 having an elongated closure layer 614 over the flexible film 612. The elongated closure layer 614 extends from the leading edge 660 to the trailing edge 662 of the package 605. The separation cut 644 is a straight cut in the illustrative example of
An additional flexible film package blank 705 is shown in
A tab score 715 is formed in the flexible film 712 near the leading edge 760 and includes a series of repeating straight lines. A tab cut 768 is formed through the flexible film 715 and the continuous closure layer 714. The tab cut 768 is positioned in between the leading edge 760 of the package and the tab score 715. For a package formed of the flexible film blank 705, a consumer can grasp a tab portion 740, having a tab leading edge that is formed by the tab cut 768 and a tab trailing edge that is formed by one of the lines of tab score 715 that intersect with the first end seal area 742. At the tab portion 740, a portion of the flexible film 712 is removed from a remainder of the flexible film to cover the pressure sensitive adhesive disposed on the surface of the elongated closure layer 714 that faces the film 712.
As noted above, the packages described herein may be formed in a variety of manners. For example, the packages may be formed in-line just prior to forming a package around a product or may be formed just prior to filling a package with product. As another example, the packages may be formed off-line well before the products are packaged. If the packages are formed off-line, the packages may be formed in a remote location away from the location where the packages are filled with product.
Before the flexible film is formed into a package, a continuous closure layer 914 may be applied to a flexible film web 912. In one example shown in
In yet another configuration, illustrated in
The laminate including the scored flexible film web 1112 and the continuous closure layer 1114 then may be wound on a laminate roll 1184. This laminate roll 1184 may be subsequently brought to a packaging line for use in forming individual package filled with product. The packaging line may be within the same facility as the laminate forming equipment illustrated in
One exemplary in-line process 1200 for producing flexible film packages is shown in
In addition, while these two schematic views illustrate two exemplary manners of forming some of the package configurations described herein, additional elements may be added to form some of the packages. For example, to form packages from package blank 705 (
Turning now to
The various configurations of package 10′ can be formed by joining opposing sides of the flexible film 12′ together to form a seal 14′. By one approach, the flexible film 12′ preferably has a sealant layer on an interior surface thereof. End seals, such as trailing and leading end seals 18′, 20′ also may be provided. By one approach, the leading end seal 20′ may be non-peelable seals, i.e., a destructive seal where the sealant layers are considered to have bonded and do not separate from one another when pulled apart, such as that found in
Conventional film package end seals may not allow a user to easily open the package at the end seal itself, especially if very small or no free ends or unsealed portions are distally adjacent the end seals. In such configurations, the body of the package film may be grasped, and the package panels pulled apart to open the package. As disclosed herein, a tab portion may be provided to allow easier opening of the package. In one example, the leading end seal 20′ has a pair of tabs 22′ (one formed in the upper and lower portion of the flexible film) formed distal to the end seal 20′. As illustrated, tabs 22′ are radially shaped tabs, though other shapes are possible. The tabs 22′ provide a finger grip to initiate opening of the package. A trailing package edge 24′ shows a concave radial shape corresponding to the shape of the tab 22′ adjacent the leading edge. The reciprocal shape of the leading and trailing edges are formed when the flow-wrap package 10′ is formed or separated from a roll of film or when the packages are separated from one another.
in the configuration of
As noted above, laser-formed scores or mechanically-formed or rotary die cuts may be formed into the flexible film 12′ and may define a package opening and/or the tab portion. The score may be added to the film surface that becomes the interior of the package. In addition, the die cutting or laser scoring of the film 12′ is not limited to a particular gauge of material or composition. Thus, a variety of films may be used in the packages, which gives the package and the process for forming the package some flexibility. In addition, this can result in a product that is more cost effective than that found in the prior art. The tear strength of the score 42′ may be at least weaker than the adhesive strength of the pressure sensitive adhesive 30′ to permit a portion of film 12′ to peel back with the label 40′.
By one approach, the score 42′ only extends through a portion of the package to avoid negatively affecting the barrier properties of the package 10′. If the score 42′ is a partial depth score line, the label 40′ may not need to provide the initial hermetic barrier, though optionally it can. By yet another approach, the score 42′ extends through the entire depth of the package film. The optional barrier properties of the label 40′ may result from an inherent characteristic of the label material, or through an added barrier layer to label 40′ (not shown). Further, in configurations where the score 42′ may affect barrier properties of the film 12′, the label 40′ may be configured to compensate for the compromised barrier properties.
A variety of differently configured score lines may be incorporated into package 10′. For example, depending on the packaging materials, configuration, and product specifications, the desired package opening and tab may change. The seal area or end seal can stop or inhibit propagation of a score or the score pattern itself may be configured to provide such control.
As shown in
To facilitate grasping and pulling of tab 22′, the label 40′ may include an adhesive free area 50′. While some previously described configurations disclosed a portion 38 of the flexible film 12 peeling upward from the remainder of the package, other configurations (such as
As discussed above, in addition to an adhesive-free or adhesive-deadened zone, the tack-free tab may be formed by having a portion of film cover the adhesive. In sum, a portion of film 12′ may separate from the remainder of the film 12′ to cover the adhesive. As shown, for example, in
Exposed score lines tend to propagate a continued tear in use. Specifically, as a score line is being separated or ruptured the film will continue tearing past the point where the score line is originally formed in the film once the score line has begun separating. Thus, score lines may be configured to inhibit or resist this tendency. For example,
In addition to the “smile” portion 56′, score line 42a′ also includes a single, straight portion that separates into two portions that angle outward before becoming parallel to one another closer to the leading end seal. The score line 42a′ extends to the leading edge of the package 10′.
As discussed above, a continuous closure layer or label 40′ may be applied to the exterior side of film 12′ that is directed to the outside of package 10′, preferably using a pressure sensitive adhesive. The label 40′ preferably covers at least the score lines 42′. The peel strength between the surface of the package 10′ and the label 40′ is greater than the force required to separate sides of the score line 42′. Further, label 40′ is peelable with respect to package 10′. For example,
The label 40′ may be any film with an adhesive coving such as, for example, a flexible film with pressure sensitive adhesive, a tape, label, or linerless label that is continuously applied longitudinally to the flow of film, unlike discrete labels known in the art. By one approach, a linerless label may be a facestock having a pressure sensitive adhesive coating on one side and can be rolled onto a spool without a liner. For example, a release coating may be applied to the side of the label opposite the side with pressure sensitive adhesive. Facestocks may include, for example, standard paper, film, plastic, fabric, foil, direct thermal, and the like. In addition, linerless labels are available with removable and repositionable adhesives.
If tape or a linerless label are employed, the liner waste is eliminated. In addition, precise registration of the label on each package is no longer required due to the continuous application of the label on the flow of package film. Though the package 10′ may be formed with a continuously disposed label 40′, the package 10′ may also be formed with a discrete label 40b′, 40c′, 40d′ as shown in
As noted above, additional scoring, such as tab score 15 previously discussed, may be employed to assist in forming a tab. As illustrated in
Another configuration, illustrated in
Flexible film packages 10′ may be fixated and assembled in a variety of manners. An exemplary process 60′ for forming flexible film packages is schematically illustrated in
The end seals 18′, 20′ may be formed once product 46′ has been placed in the interior space of package 10′. End seals 18′, 20′ also can define package 10′ width or length. The seals 14′, 18′, 20′ are preferably hermetic seals that form a gas and moisture barrier. Similar to other seals discussed herein, the seals 14′, 18′, 20′ can be thermoformed (i.e., heat welded) or formed through other welding means. For configurations where the end seal 20′ is peelable, a low tack adhesive or a cold seal and processes for forming such seals may be used. In addition, the end seals 18′, 20′ may employ patterns, crimps, or knurls.
As noted, the label 40′ can be applied continuously along the longitudinal length of the flow or web of the film 12′. Once the products are at least partially enveloped and sealed within the web of film 12′, the film and label laminate may be cut into individual packages.
As discussed herein, the method of manufacturing and assembling the packages can employ heat seal mechanisms, cold seal mechanisms, extrusion and adhesive lamination mechanisms, and co-extrusion mechanisms. The equipment employed may depend on the desired package configuration. For example, if tab 22′ includes a cut-out portion of film 12′ adhered to the label 40′, the tab 22′ may be created by adhering or applying the label 40′ to the film 12′ and scoring and/or cutting the tab 22′. In addition, various score configurations may be employed, and the equipment for forming the score line may depend on the score configuration thereof.
The exemplary method 60′ of making packages, shown in
In one approach, heated wheels may be pressed together to form the package seals. For example, if sealant layers are employed, the heat may activate the heat sealant layer on the interior surface of the package. In one configuration, an EVA sealant layer is disposed on the film 12′, and the heated wheels may be heated to between about 85 and 205 degrees Celsius. As noted above, line speed, film thickness, and other factors may affect formation of the seals, including a seal's peelability and hermeticity.
The fin seal 14′ and end seals 18′, 20′ optionally may be formed from patterns imprinted on heated wheels 38′ or seal jaws 62′, which may emboss the film 12′ as it is pulled through the manufacturing process. For example, the seal jaws 62′ may rotate with the film web 12′ as it moves through the production line and the seal jaws 62′ may meet to form end seals 18′, 20′ and the seal jaws 62′ also may form the tab 22′ and/or separate the packages from the film. Alternatively, the film 12′ may be cut with a tab cutter die. As the seal jaw 62′ forms a leading end seal 20′ on one package, the seal jaw 62′ may form a trailing end seal 18′ on another package. In a configuration where the seal jaws 62′ form both the trailing end seal 18′ and leading end seal 20′ in the same operation, a space will be provided in the die where the film 12′ is not sealed together. This space corresponds to the space 42′ between the seals of adjacent packages. The free, unsealed portions of the packages 10′ between the end seals 18′ 20′ of adjacent packages (illustrated at 42′ in
Optional or alternative features also may be incorporated into the packages described herein. For example, an optional frame 32′, as shown in
Other alternative features may include a discrete label, as opposed to the continuous closure layer or label. A discrete, registered label may be applied to the package 10′ and the other seal and reseal features may be incorporated therein. For example,
Though the embodiments of
As discussed above, score lines tend to propagate a tear being formed in the film, and thus, the score may be configured to inhibit or prevent unintended tearing of the film. The score 42″ may have a pattern to reduce this tendency including, for example, a double “J” hook (
Depending on the score 42″ incorporated into the package, the opening created by the score 42″ may permit the package opening to be sufficiently large enough to easily serve and access a substantial portion of the product contained therein. Further, in some configurations, the tendency of the flexible film to create a significant opening is, in part, due to the tendency of the flexible film to revert back to its flat sheet form. This tendency may be especially evident for discrete stacks of generally round or oval-shaped products, such as a sleeve of round cookies, crackers, or biscuits, to note but a few. This occurs primarily when no frame is used within the flexible film of the package.
Alternatively, the score 42″ may include a straight line extending longitudinally completely or partially along the length of the package, as shown in
As discussed above, the leading end seal 20″, like leading end seal 20′, may have a tab 22″ formed distal thereto. In one approach, the tab 22″ can be a “v” shaped tab, though other configurations, such as a square shaped or radial shaped tab, are possible. The tab 22″ provides a finger grip to initiate opening of the package 10″. A trailing package edge may include a concave shape corresponding to the shape of the leading edge tab 22″. The leading end seal 20″ may be peelable, i.e., have sealant layers that are separable from one another.
As shown in
As discussed above, package 10″ may be formed in a variety of processes. In one illustrative package illustrated in
One exemplary manner of forming film packages 10″ is illustrated as 60″ in
The various configurations of the flexible film package disclosed herein may be provided a package integrity feature that would indicate to a consumer whether or not the package has been previously opened.
By one approach, after the consumer has removed some of the products from the flexible film package, the flexible film may be rolled, folded, or otherwise flattened to evacuate air from inside of the package. Then, the elongated closure layer 14 may be wrapped over the rolled film and the product within the package making the package smaller, with less air space and, thus, may improve shelf-life of the product (see, e.g.,
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/345,785, filed May 18, 2010, U.S. Provisional Application Ser. No. 61/345,778, filed May 18, 2010, and U.S. Provisional Application Ser. No. 61/453,872, filed Mar. 17, 2011, each of which are incorporated herein by reference in their entirety herein.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2011/037054 | 5/18/2011 | WO | 00 | 2/4/2013 |
Number | Date | Country | |
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61345778 | May 2010 | US | |
61345785 | May 2010 | US | |
61453872 | Mar 2011 | US |