Patent Grant
9428307
This disclosure relates generally to reclosable fasteners for flexible packages and, in particular, to adhesive-based reclosable fasteners with open/close visual indicators for flexible packages.
Several types of closures or fasteners are available for reclosing a previously opened flexible package. For example, it is common to use mechanical reclosable fasteners, such as slider zippers, clips, tabs, interlocking strips, and the like. Such mechanical closures can have colored and/or uncolored interlocking components that can both reclose a package and indicate to a user that the package has been reclosed. Such mechanical closures can be expensive, bulky, complex structures that require separate molding and fabrication steps prior to being joined to the flexible film used to form the package. In addition, while mechanical closures can be applied in form-fill-seal operations, the mechanical closures often require complex and expensive manufacturing steps to apply, interconnect, and align the mechanical fastening features of each structure. Therefore, mechanical reclosable fasteners often add undue complexity and cost to the manufacturing process of the flexible packages.
Adhesive-based reclosable fasteners provide one alternative to the mechanical fasteners. For example, thermoplastic elastomers, which are sometimes called thermoplastic rubber, have been used to form reclosable pressure sensitive adhesive type fasteners. Some types of thermoplastic elastomer copolymers (especially certain styrenic block polymers) demonstrate high cohesive properties, and at the same time have low tack levels or a reduced tendency to adhere to unlike materials (i.e., food materials such as cookies, crackers, shredded cheese and the like). Such adhesive-based reclosable fasteners typically include adhesive material, typically in the form of strips, formed opposite one another on interior surfaces of the side walls of the packages. One draw-back of the known adhesive-based reclosable fasteners is that they do not typically provide an indicator to tell the consumer whether the package has been properly or improperly closed or reclosed. While some adhesive-based reclosable fasteners include color-changing indicators, such color-changing indicators may be ineffective for some users because the color change is not readily apparent, and for other users because they happen to be color-blind. Further, production of such color-changing adhesive-based reclosable fasteners adds complexity and cost to the flexible packaging manufacture.
In one approach, a flexible package comprises a top end, a bottom end, a first side edge, a second side edge opposite the first side edge, a front panel, and a rear panel joined together to form an interior therebetween configured to retain a product. The package further includes a first layer of adhesive material disposed on an interior surface of the rear panel. The adhesive material of the first layer includes at least one visual indicator formed by at least one area of predetermined shape that is more translucent than adjacent areas of the adhesive material of the first layer. The package also includes a second layer of adhesive material disposed on an interior surface of the front panel. The second layer of adhesive material is positioned opposite the first layer of adhesive material to permit the flexible package to be sealed when the first layer of adhesive material and the second layer of adhesive material are brought into contact with each other. When the flexible package is not sealed, the at least one visual indicator in the adhesive material of the first layer is not visible through the adhesive material of the second layer, and when the flexible package is sealed, the at least one visual indicator is visible through the second layer of adhesive material.
The first layer and second layers of adhesive material may be in a form of at least one strip extending from the first side edge to the second side edge of the flexible package.
The shape of the at least one visual indicator can be one of a geometric shape selected from one of circular, rectangular, triangular, and polygonal, and a calligraphic shape selected from one of single words and phrases.
The adhesive material of the first and second layers of adhesive material may be partially opaque or translucent and may include a colorant in an amount of approximately from about 0.1 percent to about 4 percent by weight. The colorant may be selected from one of titanium dioxide, calcium carbonate, talc, or any of a variety of organic of inorganic colorants, either alone, or in combinations.
The first and second layers of adhesive material may each have a thickness of approximately from about 0.0001 to about 0.005 inches.
The first layer of adhesive material may be partially opaque except for the at least one area that is more translucent than adjacent areas of the adhesive material and forms the at least one visual indicator, and the second layer of adhesive material is partially opaque or uniformly translucent.
In one approach, a method of manufacturing the flexible package described herein comprises applying the first layer of adhesive material including the at least one area of predetermined shape to a portion of the interior surface of the rear panel of the flexible package, and applying the second layer of adhesive material to a portion of the interior surface of the front panel of the flexible package opposite the portion of the interior surface of the rear panel of the flexible package.
The method may include bringing the front panel and the rear panel of the flexible package toward each other until the first layer of adhesive material comes into contact with the second layer of adhesive material and the flexible package is sealed.
The method may also include applying the second layer of adhesive material to the portion of the interior surface of the front panel of the flexible package continuously from the first side edge of the flexible package to the second side edge of the flexible package.
The method can also include applying the first layer to the portion of the interior surface of the rear panel of the flexible package continuously from the first side edge of the flexible package to the second side edge of the flexible package.
In one form, the first and second layers of adhesive material each include a colorant in an amount of approximately from about 0.1 percent to about 4 percent by weight.
In one approach, a method of reclosing the flexible package described herein comprises bringing the front panel and the rear panel of the flexible package toward each other until the first layer of adhesive material comes into contact with the second layer of adhesive material and the at least one visual indicator in the first layer of adhesive material is visible through the second layer of adhesive material.
In one approach, a flexible package including a reclosable fastener comprises a top end, a bottom end, a first side edge, a second side edge opposite the first side edge, a front panel, a rear panel joined together to form an interior therebetween configured to retain a product, and a reclosable fastener. The reclosable fastener includes a first strip of adhesive material disposed on an interior surface of the rear panel such that the adhesive material of the first strip has a first translucence level and including at least one area forming a visual indicator and being more translucent than adjacent portions of the first strip of the adhesive material. The reclosable fastener also includes a second strip of adhesive material disposed on an interior surface of the front panel such that the adhesive material of the second strip has a second translucence level. The second strip of adhesive material is positioned opposite the first strip of adhesive material to permit the flexible package to be sealed when the first strip of adhesive material and the second strip of adhesive material are brought into contact with each other. When the flexible package is sealed, the reclosable fastener has a third translucence level in portions where the first strip of adhesive material is in contact with the second strip of adhesive material and a fourth translucence level where the at least one visual indicator is in contact with the second strip of adhesive material, the fourth translucence level being about 25-75% more translucent than the third translucence level such that the at least one visual indicator is visible through the second strip of adhesive material.
The first and second strips of adhesive material may each extend from the first side edge to the second side edge of the flexible package.
The at least one visual indicator can have a shape that is one of a geometric shape selected from one of circular, rectangular, triangular, and polygonal, and a calligraphic shape selected from one of single words and phrases.
The adhesive material of the first and second strips may include a colorant in an amount of approximately from 0.1 percent to 4 percent by weight.
In one form, the first translucence level can be equal to the second translucence level. When the flexible package is not sealed, the at least one visual indicator in the adhesive material of the first layer may not be visible through the adhesive material of the second layer. In an approach, neither the first strip of adhesive material nor the second strip of adhesive material changes color when the first and second strips of adhesive material are brought into contact with each other to seal the package.
Generally, an adhesive fastener system of reclosable fastener including visual indicators having a variable opacity for flexible packages is provided. The adhesive fastener is an adhesive or cohesive material located on one or both of interior surfaces of the package that is sufficiently sticky to close the package and capable of multiple openings and reclosings. The system can include one or more strips or layers of adhesive coatings or applications on each of the front and rear panels forming walls of the package. In one approach, the adhesive on one of the walls can include one or more zones of predetermined patterns and shapes that are more translucent than the adjacent portions of the adhesive coatings. The shapes can be simple geometric figures, for example, circles, squares, triangles, or the like, or letters that form words and phases such as “CLOSED,” “SAFETY SEAL,” “FRESHNESS SEAL,” or the like. Due to the contrasting translucence of coated and uncoated zones of the adhesive strips, the uncoated zones provide for a variable translucence or change in degree of translucence leading to a visual appearance change of the package when the two opposing adhesive strips are joined together to close or reclose the package, indicating to a user whether the package is properly sealed.
For purposes of this application, the terms “translucence” and “translucent” will be understood as the property of a material allowing at least some incident light to pass through while the transmitted light can be scattered; the term “light scattering” will be understood as a deflection of a ray of light from a straight path, for example by irregularities in the propagation medium, particles, or in the interface between two media; the terms “opaque” and “opacity” will be understood as the property of not allowing transmission of light; the terms “transparent” and “transparency” will be understood as the property of a material allowing light to pass through without being scattered; and the term “partially opaque” will be understood as the property of a material whereby some incident light is not transmitted, i.e., either absorbed or reflected.
In one approach, a flexible package 10 having an adhesive-based reclosable fastener 12 with visual indicators 13, 15 is disclosed herein and generally illustrated in
With reference to
The top end seal 27 provides a tamper-evident feature for the package 10 such that the absence of, or the partial removal of the top end seal 27 would indicate to a consumer that the package 10 has been previously opened or tampered with. Removal of the top end seal 27 provides an access opening 31 for accessing the hollow interior 28 as well as dispensing the contents of the package 10. The package 10 may further include other folds, seals, gussets, and/or flaps as generally needed for a particular application. For instance, as shown in
Referring to
In the exemplary form shown in
In one approach, the first and second layers of adhesive material 30 and 32 of the fastener 12 are in the form of, for instance, a thin radiation-curable adhesive coating or layer which is normally transparent. In some cases, to make the fastener 12 more visible to a consumer, the first and second layers of adhesive material 30 and 32 may include a low concentration (in one approach, about 0.1 to about 4% by weight, in another approach, about 1 to about 4% by weight, in yet another approach, about 2 to about 3% by weight) of a pigment or colorant in order to provide some opacity to the adhesive. In one approach, titanium dioxide, calcium carbonate, or talc may be the pigment included in the first and second layers of adhesive material 30 and 32. The presence of pigment in the first and second layers of adhesive material 30 and 32 makes the layers 30 and 32 partially opaque, and therefore, more visible to the human eye than the transparent side walls 16 and 18 of the package 10.
In the approach depicted in
As discussed below, the areas 13 and 15 serve as visual indicators that can provide a consumer with information as to whether the package 10 has been properly sealed or not. As depicted in
As shown in the exemplary form of
The reclosable fastener 12 generally has an adhesive bond strength to permit the opposing first and second layers of adhesive material 30 and 32 to be bonded together in order to close or seal the package 10. For example, when the package 10 is open as shown in
As shown in
Conversely, when the package 10 is in the fully sealed condition shown in
The variation in the visibility of the visual indicators 13 and 15 through the second layer of adhesive material 32 between the open and closed conditions of the front and back walls 16 and 18 of the package 10 advantageously provides visual indication to a consumer regarding whether the package 10 is open or closed without the use of strips that change colors when moved from an open to a closed position and without the use of interlocking members that look different when open or closed. For example, neither the first adhesive layer 30 nor the second adhesive layer 32 of the package 10 changes colors when the package 10 is moved from an open condition to a closed condition. Instead, when the second adhesive layer 32 is in contact with the first adhesive layer 30 during the closed condition of the package 10, the fastener 12 is visibly more translucent in the areas where the visual indicators 13 and 15 are present and the second adhesive layer 32 does not change color but appears less opaque or more translucent opposite the areas where the visual indicators 13 and 15 are present. In other words, when the two adhesive layers 30 and 32 are joined, the pattern of contrasting opacity level caused by the presence of the visual indicators 13 and 15 becomes visible from the perspective of a consumer looking at the package 10 through the front panel.
As shown in
In one aspect, the fastener 12 may be a cohesive-based reclosable fastener generally constructed or have a composition adapted to minimize the adhesion of the fastener 12 to undesired surfaces and still function at the same time as an effective reclosable fastener. That is, the fastener 12 can be opened and closed multiple times to seal food products or other products in the interior 28 of the package 10 during use by a consumer, but at the same time not delaminate from the front and back walls 16 and 18 that form the side walls of the package 10. In one approach, the adhesive-based reclosable fastener 12, which has a strong bond to the front and back walls 16 and 18 of the package 10, includes an adhesive having relatively low tack levels to minimize adhesion to the unwanted surfaces such as food crumbs or cheese shreds, but with a bonding or opening peel strength sufficient to enable sealing or reclosure of the package 10 and permit unbonding to allow opening and/or re-opening of the package 10.
In one form, the material forming the package 10 can be a flexible sheet material or film, which may be formed of various plastic polymers, co-polymers, papers, or foils. The film substrate may be a multi-layer coextrusion and/or a laminate with constructions to enhance interfacial bonding with the energy-cured patterned adhesive fastener 12. In general, the polymeric layers may include polyolefins such as polyethylene (high, medium, low, linear low, and/or ultra low density polymers including metallocene or polypropylene (oriented and/or biaxially oriented)); polybutylene; ethylene vinyl acetate (EVA); polyamides such as nylon; polyethylene terephthalate; polyvinyl chloride; ethylene vinyl alcohol (EVOH); polyvinylidene chloride (PVDC); polyvinyl alcohol (PVOH); polystyrene; or combinations thereof, in monolayer or multi-layer combinations. In one aspect, the material forming the package 10 includes EVA. Examples of suitable material from which the flexible package 10 can be formed may be found in U.S. Publication Nos. 2008/0131636, 2008/0118688, and 2011/0211778, incorporated herein in their entirety. Other materials may also be used for the flexible package.
The first and second layers of adhesive material 30 and 32 of the fastener 12 can be formed from various suitable adhesive materials and can be provided in the form of a solution consisting of a thermoplastic elastomer diluted with an ethylene vinyl acetate copolymer in an organic solvent or mixture of organic solvents. The fastener 12 may be also formed from a UV-curable acrylic adhesive. Materials suitable for the fastener 12 are described, for example, in U.S. Publication Nos. 2009/0279813 and 2011/0211778, both incorporated by reference herein. By one approach, a suitable flexible film that can form the front and rear walls 16 and 18 of the package 10 may be a polyethylene-based film having a thickness of, in one approach, about 0.0005 to about 0.005 inches, in another approach, about 0.001 to about 0.005 inches, in another approach, from about 0.025 to about 0.005 inches. By way of example only, the first and second layers of adhesive material 30 and 32 of the fastener 12 can have a thickness of approximately from about 0.0001 to about 0.005 inches, in another approach, about 0.0005 to about 0.001 inches, in another approach, from about 0.001 to about 0.005 inches. In one form, the area of the first adhesive layer 30 forming the visual indicator 13 extends across the entire thickness of the first adhesive layer 30, as depicted in
In one approach, the materials forming the first and second adhesive layers 30 and 32 have a relatively low tack level that limits the adhesion of the fastener 12 to unwanted materials and surfaces, such as food particles, forming equipment surfaces, rollers, and the like. By one approach, the selected adhesive materials may have a tack level to undesired surfaces of not exceeding about 5 psi when preloaded with about 4.5 pounds and generally not exceeding about 15 psi when preloaded with about 10 pounds using the ASTM probe tack test D 2979; however, the tack level may also vary depending on the particular cohesive material chosen, application thereof and measurement test used.
A suitable method of manufacturing the flexible package 10 including the first and
second layers of adhesive material 30 and 32 is described with reference to
As the flexible film 100 moves in the machine direction shown by the directional arrow in
As the flexible film 100 moved in the machine direction and along a vertical form-fill-seal device 103, the opposite longitudinal edges 102 and 104 of the flexible film 100 are folded inward such that both the longitudinal edges 102 and 104 of the flexible film 100 and the visual indicators 113 and 115 are brought toward each other as shown in
The package 200 is substantially similar to the package 10 of
The exemplary flexible packages 10 and 200 described herein provide advantages over the known packages in that they includes reclosable adhesive-based fasteners 12, 212 including visual indicators 13, 15, 213, 215 having contrasting opacity and differing translucence relative to the remainder of the fasteners 12, 212 and that can be easily applied to the flexible film from which the packages 10, 200 are formed during the manufacturing process. The visual indicators 13, 213 and 15, 215 of the fasteners 12, 212 do not rely on color changes in their operation and are easily observable even by people who are color-blind, unlike various color-changing visual indicators. To this end, in one approach, the difference in the opacity level of the reclosable fastener between the open and closed conditions is not categorical, but rather a matter of degree where the opacity level observed along the reclosable fastener appears to vary without changing the color of the fastener, between the open and closed conditions of the fasteners 12, 212. Finally, since the visual indicators 13, 213 and 15, 215 of the fasteners 12, 212 do not require any interlocking mechanical parts, the flexible packages 10, 200 are cheaper to manufacture than many of the presently known packages.
It will be understood that various changes in the details, materials, and arrangements of the package and process of formation thereof, which have been herein described and illustrated in order to explain the nature of the described package, may be made by those skilled in the art within the principle and scope of the embodied method as expressed in the appended claims.
This application is a U.S. national phase application of International Application No. PCT/US2014/021084, filed Mar. 6, 2014, which claims benefit from U.S. Application 61/793,341, filed Mar. 15, 2013, which are hereby incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2014/021084 | 3/6/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/149825 | 9/25/2014 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20160023810 A1 | Jan 2016 | US |
| Number | Date | Country | |
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| 61793341 | Mar 2013 | US |
