EP1584570A1

EP1584570A1 - Reclosable thermoformed flexible package and method of making same

Info

Publication number: EP1584570A1
Application number: EP05251325A
Authority: EP
Inventors: Amy L. Kraimer; Edward L. Haedt
Original assignee: Curwood Inc
Current assignee: Bemis Co Inc
Priority date: 2004-03-08
Filing date: 2005-03-04
Publication date: 2005-10-12
Also published as: BRPI0500782A; US20050194282A1; MXPA05002606A

Abstract

A reclosable flexible package (10) containing an article comprising a front flexible panel (11) and a rear flexible panel (13). The reclosable flexible package has at least one panel comprising a thermoplastic film which is thermoformed; a reclosable fastener means (25); at least one line of structural weakness (27) in the exterior surface of the front flexible panel and at least one line of structural weakness (28) in the exterior surface of the rear flexible panel; and a tamper-evident structure (29). The tamper-evident structure includes a first portion comprising the front flexible panel extending from the at least one line of structural weakness in the exterior surface of the front flexible panel to a top seal (22) (or top seal portion) and from the at least one line of structural weakness in the exterior surface of the rear flexible panel to a top seal (or top seal portion).

Description

BACKGROUND OF THE INVENTION

The present invention relates generally to reclosable flexible packages and more specifically, to reclosable flexible packages which are thermoformed and may be hermetically sealed if desired. The invention is also concerned with a method of manufacturing the packages according to the present invention.
Over the years, there have been a number of improvements to conventional flexible bags and packages for containing food and non-food items which have resulted in greater convenience to the consumer. Most notable improvements in the art have been the addition of reclosable and security features to the flexible package designs. For example, goods that are not used completely when the package is initially opened rely on a closure mechanism to reseal the package and keep the remaining contents fresh and contained therein. Reclosability may be accomplished by the use of a mechanical fasteners of various types. A common type of resealing mechanical fastener is the "zipper-type" having two interlocking zipper members and may include a slider device mounted on top of the fastener. The slider device which is connected to the two interlocking members, helps to engage the interlocking zipper members when the slider device is moved in a first direction along the zipper, thereby closing the package. The slider device also helps pry apart or disengage the interlocking zipper members when the slider device is moved in an opposite direction along the zipper, thereby opening the package. Non-mechanical fasteners have also been used to provide reclosability which include peelable and resealable strips and adhesives.
Since reclosable packages can easily be opened, tamper-evident features have been added which alert the consumer to any breach of security prior to purchase. Often the tamper-evident feature is a structural feature such as a hood or shroud which covers part or all of the reclosable fastener which must be removed in order to operate to the reclosable fastener.
By way of example, attention is directed to the following U.S. Patents as representative of various approaches of packages having a reclosable and/or tamper-evident features with which the present invention relates by way of improvement:
U.S. Patent Nos. 4,246,288 and 4,437,293 disclose a reclosable package and a method and apparatus for making such a reclosable package.
U.S. Patent No. 4,823,961 to Griesbach et al. and U.S. Patent No. 4,925,316 to Van Erden et al., describe hermetically sealed non-thermoformed packages having a reclosable fastener means comprising interlocking closure strips being operable responsive to digital pull-apart force for accessing the contents reserved in the package.
U.S. Patent No. 5,246,720 to Buchko describes a flexible reclosable package which is thermoformed and includes an interlocking fastener means. A score-line is provided adjacent to the top seal which facilitates the removal of the top to gain access into the package.
U.S. Patent No. 6,360,513 to Strand et al. discloses a non-thermoformed reclosable bag for filling with a food product. The package is provided with a zipper-type interlocking fastener means and slider device which is covered with a folded-hood structure that serves as a tamper-evident feature. Two score-lines are also included to help remove the folded-hood structure.
U.S. Patent No. 6,517,242 to Buchman describes non-thermoformed packages having a reclosable fastener means comprising a zipper-type interlocking closure fastener with a slider device. Disclosed are packages that are provided with a tamper-evident feature of various structures. Lines of structural weaknesses are also provided with which to aid in the removal of the tamper-evident structure.
U.S. Patent Application No. 2003/0219176 to Koccher et al. and U.S. Patent Application No. 2003/02318811 to Hodson et al. also describe non-thermoformed packages having a reclosable fastener means comprising a zipper-type interlocking reclosable fastener means with a slider device, and lines of weakness in the package panels.
U.S. Patent Application No. 2003/0219173 to Schneider discloses a thermoformed package having a reclosable fastener means comprising a zipper-type interlocking reclosable fastener means with a slider device and a tamper-evident structure which covers the reclosable fastener means. A line of structural weakness is provided in the non-thermoformed package panel to help in the removal of the tamper-evident structure.
Notwithstanding the fairly high state of development in the art, packaging manufacturers are continually striving to improve the functionality of their flexible packages.

SUMMARY OF THE INVENTION

The present invention is directed to thermoformed flexible packages suitable for packaging food and non-food items. In accordance with the present invention, the packages are provided with a reclosable fastener means which allow the consumer to open and reclose the package at his or her own discretion. The packages are further provided with a tamper-evident structure which preserves the integrity of the package before purchase and may be easily removed to gain access to the reclosable fastener means of the package. Accordingly, the packages may further be hermetically sealed to protect the food and non-food items contained therein.
The packages of the present invention include a front flexible panel having an interior surface and an exterior surface and comprising a first thermoplastic film. The packages also include a rear flexible panel having an interior surface and an exterior surface and comprising a second thermoplastic film which is thermoformed. The front flexible panel and rear flexible panel each have a perimeter having a first peripheral side edge and an opposing second peripheral side edge, connected by a peripheral top edge and an opposing bottom peripheral edge. The interior surface of the front flexible panel is joined to the interior surface of the rear flexible panel by either a contiguous seal or a plurality of seals. The contiguous seal includes a first side seal portion, an opposing second side seal portion, and a top seal portion, an opposing bottom seal portion in which the seal portions are connected to form a seal perimeter between the front flexible panel and rear flexible panel thereby forming a receptacle cavity. Alternatively, the plurality of seals includes a first side seal, an opposing second side seal, and a top seal, an opposing bottom seal in which the seals are connected to form a perimeter between the front flexible panel and rear flexible panel thereby forming a receptacle cavity.
The package further includes a reclosable fastener means which allow a consumer to gain access to the receptacle cavity of the package. The reclosable fastener means is disposed between the interior surface of the front flexible panel and the interior surface of the rear flexible panel. A tamper-evident structure is also incorporated into the package to encompass the reclosable fastener means thereby giving the consumer a visual indication that the integrity of the package has been compromised. The tamper-evident structure serves as a barrier to the reclosable fastener means by having a first portion comprising the front flexible panel which extends from at least one line of structural weakness in the exterior surface of the front panel to either the top seal portion or top seal, and a second portion comprising the rear flexible panel which extends from at least one line of structural weakness in the exterior surface of the rear panel to either the top seal portion or the top seal.
To facilitate the removal of the tamper-evident structure, the package further includes at least one line of structural weakness in the exterior surface of the front panel which extends transversely from one side peripheral edge of the package to the opposite second side peripheral edge, and at least one line of structural weakness in the exterior surface of the rear panel which extends transversely from one side peripheral edge of the package to the opposite second side peripheral edge. The at least one line of structural weakness in the exterior surface of the front panel and the at least one line of structural weakness in the exterior surface of the rear panel are both positioned below and adjacent to the reclosable fastener means.
In one embodiment, the inventive package includes an interior surface of the front flexible panel joined to the interior surface of the rear flexible panel by a contiguous seal such that the contiguous seal comprises a first side seal portion, an opposing second side seal portion, and a top seal portion, an opposing bottom seal portion. The seal portions are connected to form a seal perimeter between the front flexible panel and rear flexible panel thereby forming a receptacle cavity.
Each seal portion may be either a hermetic seal or a non-hermetic seal, preferably, a hermetic seal.
In another embodiment, the inventive package includes an interior surface of the front flexible panel joined to the interior surface of the rear flexible panel by a plurality of seals comprising a first side seal, an opposing second side seal, and a top seal, an opposing bottom seal. The seals are connected to form a perimeter between the front flexible panel and rear flexible panel thereby forming a receptacle cavity.
Preferably, the first side seal extends longitudinally between the peripheral top sedge and the peripheral bottom edge and is positioned proximate to the first peripheral side edge; the second side seal is opposite to the first side seal and extends longitudinally between the peripheral top sedge and the peripheral bottom edge and is positioned proximate to the second peripheral side edge; the top seal extends transversely from the first peripheral side edge to the second peripheral side edge and is positioned proximate to the peripheral top edge; and the bottom seal is opposite to the top seal and extends transversely from the first peripheral side edge to the opposing second peripheral side edge and is positioned proximate to the peripheral bottom edge.
Each seal may be either a hermetic seal or non-hermetic seal, preferably, a hermetic seal.
In a particular embodiment, the present invention is directed to a thermo formed reclosable package having a reclosable fastener comprising a peelable resealing strip.
In another particular embodiment, the present invention is directed to a thermoformed reclosable package having a reclosable fastener comprising a first interlocking member and a second interlocking member. Preferably, the first interlocking member and the second interlocking member are adapted to engage and disengage with each other.
In another particular embodiment, the present invention is directed to a thermoformed reclosable package having a reclosable fastener comprising a first interlocking member, a second interlocking member and a slider device. Preferably, the first interlocking member includes an attachment flange. Preferably, the second interlocking member includes an attachment flange.
In still another particular embodiment, the inventive package includes a reclosable fastener means comprising a first interlocking member having a attachment flange which is sealed to the interior surface of the front flexible panel, and a second interlocking member having a attachment flange which is sealed to the interior surface of the rear flexible panel.
Preferably, the at least one line of structural weakness in the exterior surface of the front flexible panel has a depth which is less than the entire thickness of the front flexible panel.
Preferably, the at least one line of structural weakness in the exterior surface of the rear flexible panel has a depth which is less than the entire thickness of the rear flexible panel.
Preferably, the taper-evident structure covers a portion of the reclosable fastener means, more preferably, the taper-evident structure covers the entire reclosable fastener means.
In yet another particular embodiment, the inventive package includes a frangible seal joining the interior surface of the front flexible panel to the interior surface of the rear flexible panel and extends transversely from the first peripheral side edge to the opposing second peripheral side edge and is positioned below and adjacent to the at least one line of structural weakness in the exterior surface of the front flexible panel and the at least one line of structural weakness in the exterior surface of the rear flexible panel.
This disclosure is also directed to a process of manufacturing the reclosable thermoformed packages for containing an article.
In one particular embodiment, the present invention is directed to a method comprising dispensing a rear flexible panel from a first roll in which the rear flexible panel comprises a first thermoplastic film; providing a reclosable fastener means; tacking the reclosable fastener means to the interior surface of the rear flexible panel; thermoforming the rear flexible panel; placing an article onto the rear flexible pane; dispensing a front flexible panel from a second roll to cover the article; joining the reclosable fastener means to both the interior surface of the rear flexible panel and the interior surface of the front flexible panel to form a seal perimeter between the front flexible panel and the rear flexible panel thereby defining a receptacle cavity therewithin, such that the seal perimeter includes an aperture adapted to allow the receptacle cavity to communicate with the outside of said package; modifying the atmosphere within the receptacle cavity through said aperture in said seal perimeter; and sealing the aperture of the seal perimeter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic, front plan view of one embodiment of a thermoformed flexible package according to the present invention with a turned up corner having of a first example of a reclosable fastener means.
FIG. 2 is a schematic, cross-sectional view of one embodiment of the thermoformed flexible package taken along line 2-2 of FIG. 1.
FIG. 3 is a partially schematic, front plan view of another embodiment of a thermoformed flexible package according to the present invention with a turned up corner having of a second example of the reclosable fastener means.
FIG. 4 is a schematic view of one embodiment of a preferred process of manufacturing thermoformed flexible packages according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "thermoformed" refers to a thermoplastic film or sheet which has been heated until softened and then formed, molded, drawn, or vacuum pulled into a desired shape. In the thermoforming process, a thermoplastic film sheet is fed through an oven and heated to bring it to a thermoformable temperature. The sheet is heated to a softening point and may be either immediately shaped to the desired configuration or advanced to a forming station and then drawn to a predetermined shape. Differential pressure is maintained until the film has cooled.
As used herein, the phrase "thermoplastic film" refers to any mono-layer or multilayer polymeric materials that soften when exposed to heat and returns to its original condition when cooled to room temperature. In general, thermoplastic films may include, but are not limited to, natural polymers, biodegradable polymers, and synthetic polymers such as polyolefins, including polyethylenes, polypropylenes, polybutylenes, polyamides, polyesters, ethylene/vinyl alcohol copolymers, polyvinylidene chlorides and the like. Thermoplastic materials may also include any synthetic polymer that are cross-linked by either radiation or chemical reaction during a manufacturing process operation.
As used herein, the term "multilayer" refers to a plurality of layers in a single film structure generally in the form of a sheet or web which can be made from a polymeric material or a non-polymeric material bonded together by any conventional means known in the art, i.e., coextrusion, extrusion coating, and lamination, vacuum vapor deposition coating, solvent coating, emulsion coating, or suspension coating or combination of one or more thereof. The multilayer films may include as many layers as desired.
As used herein, the term "polymer" refers to the product of a polymerization reaction, and is inclusive of homopolymers and copolymers, including bipolymers, terpolymers, etc. In general, the layers of a film can consist essentially of a single polymer, or can have still additional polymers together therewith, i.e., blended therewith.
As used herein, the phrase "structural weakness" refers to perforations, holes, score lines, laser score lines, tear lines, tear strips, cut patterns, and microperforations in a film structure specifically designed to minimize the digital force required to tear apart a portion of a film or sheet and create a predetermined tear path for removal of a portion of the film. It should be understood that the use of the phrase "structural weakness" should include an area of the package that is intentionally designed to be easily torn by the consumer to allow exposure to the reclosable fastener means.
As used herein, the terms "joining" and "sealing" are used interchangeably and are defined as directly adhering the subject surface to the object surface using an adhesive, a cold-seal, heat-seal or other means known to those skilled in the art.
As defined herein, the term "cold-seal" refers to the union of a surface (or portion thereof) of one film to a surface (or portion thereof) of another film or of two different portions of a surface of the same film by means of an adhesive material.
As used herein, the term "heat-seal" refers to the union of a surface (or portion thereof) of one film to a surface (or portion thereof) of another film or of two different portions of a surface of the same film using heat and pressure. The heat-seal is achieved by bringing two surfaces or portions of a surface into contact, or at least close proximity, with one another and then applying sufficient heat and pressure to a predetermined area of the two surfaces to cause the contacting surfaces to become molten and intermix with one another, thereby forming as essentially inseparable fusion bond between the two surfaces in the predetermined area when the heat and pressure are removed therefrom and the area is allowed to cool.
As used herein, the phrase "hermetic seal" refers a seal on a container or package that has been completely closed by fusion (heat) or other comparable means so as to prevent any external atmosphere from entering the package through the sealed area.
As used herein, the term "tacking" refers to the step of adhering or sealing a surface of one object to a surface of a second object by either fusion (heat) or an adhesive such that the two surface are bonded temporarily. Generally, tacking a surface of one object to another surface of a second object results in a non-hermetic seal.
Although the disclosure hereof is detailed and sufficient to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures or methods. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
The present invention is both a method and a structure resulting from the method. The method of the present invention, while unique and fully described herein, may be used on machinery known to a person of ordinary skill in the art.
While reclosable flexible packages using various reclosable fastener means and tamper-evident structures are well known, it is believed that the advantages of the present invention are not apparent from the known reclosable packages of the prior art.
Attention is directed to the present invention which will be described hereunder in detail with reference to the accompanying drawings mentioned above, wherein like numerals represent like parts throughout the several views.
FIG. 1 is a schematic, front plan view of a thermoformed flexible package of one embodiment of the reclosable fastener means according to the present invention. As shown, package 10 is depicted with a turned up corner comprising a front flexible panel 11 having an interior surface 12a (See FIG. 2) and an exterior surface 12b and a rear flexible panel 13 having an interior surface 14a (See FIG. 2) and an exterior surface 14b, the latter (i.e., rear flexible panel 13) being thermoformed to provide a receptacle cavity 15 (See FIG. 2) for containing a food or non-food item. The interior surfaces and exterior surfaces of front and rear flexible panels 11 and 13 are relative to the package 10.
It should be appreciated by a person of ordinary skill in the art that the front flexible panel 11 may comprises any mono-layer or multilayer thermoplastic film suitable for packaging food and non-food items and should not be limited to any particular film composition. It should also be appreciated by those skilled in the art that the rear flexible panel 13 may be any mono-layer or multilayer thermoplastic film capable of being thermoformed and suitable for packaging food and non-food items. The rear flexible panel 13 may comprise thermoplastics which include, but is not limited to, polyesters, preferably, polyethylene terephthalates, most preferably, non-oriented polyethylene terephthalates, polyamides, preferably, cast polyamides and blends thereof, such as those films described in U.S. Pat. Application No. 10/237,949 to Schell et al., entitled "Packaging Films Containing Coextruded Polyester And Nylon Layers", which is expressly incorporated herein by reference.
It should also be appreciated by a person of ordinary skill in the art that the mon-layer or multilayer thermoplastic films in view of the present invention and described hereinabove may be provided by conventional film forming processes which include, but are not limited to, for example, extrusion, coextrusion, single- or double-bubble blown film extrusion, cast extrusion, lamination, coating lamination or similar processes or a combination thereof.
The depicted package 10 has a first peripheral side edge 16 and opposing second peripheral side edge 17. The first peripheral side edge 16 and opposing second peripheral side edge 17 are connected by a peripheral top side 18 and opposing peripheral bottom side edge 19. It is understood that the terms "top" and "bottom" are relative terms used in respect to package 10 as shown in FIGS. 1-3. It is further understood that package 10 can be oriented in different directions, so that, for example, peripheral top side18 would not be at the top most portion of the figure but would be positioned else where.
Interior surface 12a (See FIG. 2) of front flexible panel 11 is joined to interior surface 14a (See FIG. 2) of rear flexible panel 13 by a plurality of seals which include a first side seal 20, an opposing second side seal 21, and a top seal 22, an opposing bottom seal 23. The seals are connected to form a seal perimeter 24 between front flexible panel 11 and rear flexible panel 13 thereby forming a receptacle cavity 15 (See FIG. 2) of package 10. First side seal 20, opposing second side seal 21, and top seal 22, opposing bottom seal 23 may each be a cold-seal or a heat-seal, preferably, a heat-seal, most preferably, a hermetic heat-seal.
A reclosable fastener means 25 having a slider device 26 is provided across the top portion of package 10 extending from first peripheral side edge 16 to second peripheral side edge 17. A slider device 26 is mounted on reclosable fastener means 25 to facilitate opening and closing of the reclosable fastener. Suitable reclosable fastener means according to the present invention may include, but are not limited to, those reclosable fastener means having interlocking members, preferably, interlocking members and a slider device. Suitable reclosable fastener means, in general, are known and are taught, for example, in U. S. Patent Nos. 5,063,644; 5,301,394; 5,442,837; 5,964,532; 6,409,384; 6,439,770; 6,524,002; 6,527,444; 6,609,827; 6,616,333; 6,632,021; 6,663,283; 6,666,580; 6,679,027; and U.S. Patent Application Nos. 2002/0097923; and 2002/0196987, each of which is incorporated by reference herein. It will be noted that the reclosable fastener means is not limited to any particular number of interlocking members and/or slider device structure. It will be appreciated that the reclosable fastener means may be chosen which does not include a slider device and/or interlocking members.
Referring to FIG. 1, on the exterior surface 12b of front flexible panel 11 is at least one line of structural weakness 27 and on the exterior surface 14b of rear flexible panel 13 is at least one line of structural weakness 28. Formation of the at least one line of structural weakness 27 and 28 maybe accomplished by methods disclosed in U.S. Patent Nos. 3,626,143; 3,909,582; 4,778,058; 4,834,245; 5,001,325; 5,613,779; 5,630,308; and 6,427,420, which are hereby incorporated by reference. It will be appreciated that both at least one line of structural weaknesses 27 and 28 may be provided in a variety of shapes including curves or sinusoidal and may also be provided either continuously or intermittently across exterior surface 12b of front flexible panel 11 and across exterior surface 14b of rear flexible panel 13 from first peripheral side edge 16 to second peripheral side edge 17. While at least one line of structural weaknesses 27 may be provided having a depth of the entire thickness of front flexible panel 11 and at least one line of structural weaknesses 28 may be provided having a depth of the entire thickness of rear flexible panel 13 rear flexible panel 13, e.g. by intermittent perforations or slits, it is preferred that each of the at least one line of structural weaknesses has a depth of less than the entire thickness of the panel that it is formed on. It will be appreciated that one or both of the at least one line of structural weakness 27 and 28 may be provided in any length across each panel between from first peripheral side edge 16 to second peripheral side edge 17. It will be understood that each of the at least one line of structural weakness 27 and 28 may positioned in anywhere between top peripheral edge 18 and opposing bottom peripheral edge 19 with the proviso that each of the at least one line of structural weakness is positioned below the reclosable fastener means 25. Package 10 has a tamper-evident structure 29 which is further described below with respect to FIG. 2.
FIG. 2 illustrates a cross-sectional view of one embodiment of package 10 taken along line 2-2 of FIG. 1. It should be especially noted that FIG. 2 is a schematic drawing and therefore not to scale having features exaggerated or otherwise dimensioned to facilitate clarity of description. As best seen in FIG. 2, package 10 has a tamper-evident structure 29 having a first portion 30 comprising front flexible panel 11 which extends from the at least one line of structural weakness 27 to the top seal 22 and a second portion 31 comprising rear flexible panel 13 which extends from the structural weakness 28 to the top seal 22. It will be appreciated that tamper-evident structure 29 provides an envelope within which reclosable fastener means 25 (and, if included, slider device 26) reside. It will also be noted that the tamper-evident structure 29 is positioned over reclosable fastener means 25 (and, if included, slider device 26) as a barrier to the reclosable fastener means 25 and slider device 26. It will be also appreciated that to gain access to the receptacle cavity 15 (See FIG. 2), the tamper-evident structure 29 needs to be either partially or entirely removed, thereby further giving a visual indication that the integrity of the package has been compromised. It will be further appreciated that both of the at least one line of structural weaknesses 27 and 28 serve to facilitate the removal of the tamper-evident structure 29.
The reclosable fastener means 25 is shown comprising a first interlocking member 32 with an attachment flange 33 and a second interlocking member 34 with an attachment flange 35. It will be appreciated that first and second interlocking members 32 and 34 may each include an attachment flange which may be integral to the first and second interlocking members. As is shown in FIG. 2, the first interlocking member 32 is adhered to the interior surface 12a of the front flexible panel 11 via attachment flange 33 and the second interlocking member 34 is adhered to the interior surface 14a of rear flexible panel 13 via attachment flange 35. A receptacle cavity 15 of package 10 is provided between the interior surface 12a of front flexible panel 11 and the interior surface 14a of rear flexible panel 13 being delimited by first seal 20 (See FIG. 1), opposing second side seal 21 (See FIG. 1), and top seal 22, opposing bottom seal 23.
FIG. 3 is a partially schematic, front plan view of another embodiment of a thermoformed flexible package 10' according to the present invention with a turned up corner and includes a second example of the reclosable fastener means. Package 10' is depicted having interior surface 12'a of front flexible panel 11' joined to interior surface 14'a of rear flexible panel 13' by a contiguous seal 36. Contiguous seal 36 includes a first seal portion 37, an opposing second side seal portion 38, and a top seal portion 39, an opposing bottom seal portion 40. The seal portions are connected to form a seal perimeter 24' between front flexible panel 11' and rear flexible panel 13' thereby forming receptacle cavity 15'. Reclosable fastener means 25' is depicted without a slider device. Reclosable fastener means 25' may further comprise, if desired, a first interlocking member 32' (not shown) and a second interlocking member 34' (not shown) and attachment flanges 33' and 35' (both not shown). Reclosable fastener means 25' is provided across the top portion of package 10' extending from first peripheral side edge 16' to second peripheral side edge 17'. Suitable reclosable fastener means of this type, in general, are known to those skilled in the art and have been described in detail in U.S. Patent Nos. 4,782,951; 4,786,190; 4,823,961; 4,925,316; 5,014,856; and 5,050,736, the disclosures of which are hereby incorporated by reference.
Alternatively, the reclosable fastener means may comprise either an adhesive or a peelable resealing strip, both of which are suitable for use in the present invention. These types of reclosable systems, in general, are known to those skilled in the art and are taught in, for example, U.S. Patent Nos. 3,454,210; 4,415,087; 5,078,509; 5,089,320; 5,172,854; 5,382,472; and 5,882,749, the disclosures of which are hereby incorporated by reference.
Referring again to FIG. 3, on the exterior surface 12'b of front flexible panel 11' is at least one line of structural weakness 27' and on the exterior surface 14'b of rear flexible panel 13' is at least one line of structural weakness 28'. Package 10' is also depicted as having an optional frangible seal 41. Frangible seal 41 joins the interior surface 12'a of front flexible panel 11' to the interior surface 14'a of rear flexible panel 13' and is provided transversely across from first side seal 20' to opposing second side seal 21' disposed adjacent to and below the structural weaknesses 27' and 28'. Frangible seal 41 may be used to provide an additional tamper-evident feature to packages according to the present invention.
FIG. 4 is a schematic view of one embodiment of a preferred process of manufacturing thermoformable flexible packages according to the present invention. The process line progresses from left to right so that the final filled package, such as, for example, package 10 as illustrated in FIG. 1, is at the right side of the figure. Starting at the left-hand side of FIG. 4, rear flexible panel 13 having an interior surface 14a, an exterior surface 14b and at least one line of structural weakness 28 (See FIG. 1) in exterior surface 14b, is dispensed from roll 42. A reclosable fastener means 25 having first interlocking member (See FIG. 2) with attachment flange (See FIG. 2), and second interlocking member (See FIG. 2) with attachment flange (See FIG. 2) is provided from roll 43 and then tacked to the interior surface 14a of rear flexible panel 13 at point 44. A heating device 45 may be used to soften exterior surface 14b (underside) of rear flexible panel 13 so that rear flexible panel 13 may be thermoformed at point 46. Next, an article such as a food or non-food item is placed onto rear flexible panel 13 at point 47.
The next step of the inventive process is dispensing front flexible panel 11 having interior surface 12a, exterior surface 12b and at least one line of structural weakness 27 in exterior surface 12b from roll 48 to cover the article at point 49. Specifically, front flexible panel 11 is disposed such that the at least one line of structural weakness 27 in exterior surface 12b is parallel with and, preferably, superimposed over the at least one line of structural weakness 28 in exterior surface 14b of rear flexible panel 13 as depicted in FIG. 2.
Reclosable fastener means 25 is then joined to both interior surface 12a of front flexible panel 11 and interior surface 14a rear flexible panel 13 at point 50. Alternatively, if interlocking members 32 and 34 are present as part of the reclosable fastener means 25, then interlocking member 32 is joined to interior surface 12a of front flexible panel 11 and interlocking member 34 is joined to interior surface 14a of rear flexible panel 13. Alternatively, if attachment flanges 33 and 35 are present as part of interlocking members 32 and 34, respectively, then reclosable fastener means 24 is secured to package 10 by joining attachment flange 33 to interior surface 12a and attachment flange 35 to interior surface14a as depicted in FIG. 2.
Next, at point 51, front flexible panel 11 is joined to rear flexible panel 13 to form a seal perimeter 24 (See FIG. 1) between front flexible panel 11 and rear flexible panel 13 thereby forming a receptacle cavity 15 (See FIG. 2) of package 10. Preferably, seal perimeter 24 is formed such that an aperture 52 (not shown) is formed which is adapted to allow receptacle cavity 15 to communicate with the outside of package 10 Subsequently, at point 53, the atmosphere within receptacle cavity 15 is modified through the aperture 52. Modifying the atmosphere within receptacle cavity 15 may include, for example, but is not limited to, withdrawing the air inside the receptacle cavity and/or flushing the receptacle cavity with nitrogen or argon gas. Finally, aperture 52 is sealed at point 54 which may be performed under vacuum and/or modified-atmosphere conditions.
It should be understood that the relative order in which the process steps of the inventive method are carried out may vary such that the step of thermoforming the rear flexible panel may be performed either after the step of dispensing a rear flexible panel and before the step of providing a reclosable fastener means or after the step of tacking the reclosable fastener means to the interior surface of the rear flexible panel.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is 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.

Claims

A package containing an article, said package comprising:

a) a front flexible panel comprising a first thermoplastic film, wherein said front flexible panel includes an interior surface and an exterior surface relative to said package;

b) a rear flexible panel opposing said front flexible panel and comprising a second thermoplastic film, wherein said rear flexible panel includes an interior surface and an exterior surface relative to said package, wherein said second thermoplastic film is thermoformed,

c) wherein said front flexible panel and said rear flexible panel each have a perimeter having a first peripheral side edge and an opposing second peripheral side edge, connected by a peripheral top edge and an opposing peripheral bottom edge,

d) wherein said interior surface of said front flexible panel is joined to said interior surface of said rear flexible panel by either a contiguous seal or a plurality of seals; wherein

i) said contiguous seal comprises a first side seal portion and an opposing second side seal portion, and a top seal portion and an opposing bottom seal portion, wherein said seal portions are connected to form a seal perimeter between said front flexible panel and said rear flexible panel thereby forming a receptacle cavity;

ii) said plurality of seals comprises a first side seal and an opposing second side seal, and a top seal and an opposing bottom seal, wherein said plurality of seals are connected to form a seal perimeter between said front flexible panel and said rear flexible panel thereby forming a receptacle cavity;

e) a reclosable fastener means to provide an entree to said receptacle cavity, wherein said reclosable fastener means is positioned between said interior surface of said front flexible panel and said interior surface of said rear flexible panel;

f) at least one line of structural weakness in said exterior surface of said front flexible panel extending transversely from said first peripheral side edge to said second peripheral side edge, positioned below and adjacent to said reclosable fastener means;

g) at least one line of structural weakness in said exterior surface of said rear flexible panel extending transversely between said first peripheral side edge and said second peripheral side edge, positioned below and adjacent to said reclosable fastener means; and

h) a tamper-evident structure having a first portion comprising said front flexible panel which extends from said at least one line of structural weakness in said exterior surface of said front flexible panel to either said top seal portion or said top seal, and a second portion comprising said rear flexible panel which extends from said at least one line of structural weakness in said exterior surface of said rear flexible panel to either said top seal portion or said top seal.
A package containing an article as claimed in claim 1, wherein

a) said first side seal extends longitudinally between said peripheral top edge and said peripheral bottom edge and is positioned proximate to said first peripheral side edge;

b) said second side seal is opposite to said first side seal and extends longitudinally from said peripheral top edge to said peripheral bottom edge and is positioned proximate to said second peripheral side edge;

c) said top seal extends transversely from said first peripheral side edge to said second peripheral side edge and is positioned proximate to said peripheral top edge;

d) said bottom seal is opposite to said top seal and extends transversely from said first peripheral side edge to said second peripheral side edge and is positioned proximate to said peripheral bottom edge.
A package containing an article as claimed in claim 1 or claim 2, wherein said package is hermetically sealed.
A package containing an article as claimed in any preceding claim, wherein said reclosable fastener means comprises a first interlocking member and a second interlocking member.
A package containing an article as claimed in claim 4, wherein said first interlocking member of said reclosable fastener means further comprises an attachment flange.
A package containing an article as claimed in claim 5, wherein said attachment flange of said first interlocking member is sealed to said interior surface of said front flexible panel.
A package containing an article as claimed in any of claims 4 to 6, wherein said second interlocking member of said reclosable fastener means further comprises an attachment flange.
A package containing an article as claimed in claim 7, wherein said attachment flange of said second interlocking member is sealed to said interior surface of said rear flexible panel.
A package containing an article as claimed in any of claims 4 to 8, wherein said first interlocking member of said reclosable fastener means and said second interlocking member of said reclosable fastener means are adapted to engage and disengage with each other.
A package containing an article as claimed in any of claims 4 to 9, wherein said reclosable fastener means further comprises a slider device connected to said first interlocking member and said second interlocking member.
A package containing an article as claimed in any of claims 1 to 3, wherein said reclosable fastener means is a peelable resealing strip.
A package containing an article as claimed in any preceding claims, wherein said at least one line of structural weakness in said exterior surface of said front panel has a depth of less than the entire thickness of said front panel.
A package containing an article as claimed in any preceding claim, wherein said at least one line of structural weakness in said exterior surface of said rear panel has a depth of less than the entire thickness of said rear panel.
A package containing an article as claimed in any preceding claim, wherein said tamper-evident structure covers at least a portion of said reclosable fastener means.
A package containing an article as claimed in claim 14, wherein said tamper-evident structure covers the entire said reclosable fastener means.
A package containing an article as claimed in any preceding claim, further comprising a frangible seal joining said interior surface of said front panel to said interior surface of said rear flexible panel said frangible seal extending transversely from said first peripheral side edge to said second peripheral side edge, and being positioned below and adjacent to said at least one line of structural weakness in said exterior surface of said front flexible panel and said at least one line of structural weakness in said exterior surface of said rear flexible panel.
A package containing an article as claimed in any preceding claim, wherein said contiguous seal is a heat seal, or said plurality of seals are each a heat-seal.
A package containing an article as claimed in any preceding claim, wherein said first thermoplastic film and said second thermoplastic film are the same thermoplastic film.
A method of manufacturing a reclosable thermoformed flexible package containing an article comprising:

a) dispensing a rear flexible panel from a first roll, wherein said rear flexible panel comprises a first thermoplastic film;

b) providing a reclosable fastener means;

c) tacking said reclosable fastener means to said interior surface of said rear flexible panel;

d) thermoforming said rear flexible panel, wherein said thermoforming of said rear flexible panel is performed either after said dispensing said rear flexible panel from said first roll and before said providing said reclosable fastener means or after said tacking said reclosable fastener means to said interior surface of said rear flexible panel;

e) placing an article onto said rear flexible panel;

f) dispensing a front flexible panel from a second roll to cover said article;

g) joining said reclosable fastener means to both said interior surface of said rear flexible panel and said interior surface of said front flexible panel;

h) joining said front flexible panel to said rear flexible panel to form a seal perimeter between said front flexible panel and said rear flexible panel thereby defining a receptacle cavity therewithin, such that an aperture is formed in said seal perimeter which is adapted to allow said receptacle cavity to communicate with the outside of said package;

i) modifying the atmosphere within said receptacle cavity through said aperture in said seal perimeter; and

j) sealing said aperture of said seal perimeter.