EP0454424A1

EP0454424A1 - Tandem recloseable package and method of making same

Info

Publication number: EP0454424A1
Application number: EP91303656A
Authority: EP
Inventors: Dean F. Schwarz
Original assignee: Oscar Mayer Foods Corp
Current assignee: Oscar Mayer Foods Corp
Priority date: 1990-04-25
Filing date: 1991-04-23
Publication date: 1991-10-30
Also published as: CA2039580A1; JPH04242550A

Abstract

A flexible tandem package (100) which can be readily separated into two, distinct recloseable packages (10; 110, 210) and the method for making the same is disclosed. The package includes first and second sheets (14, 16; 114, 116) sealed to opposite surfaces of a double recloseable seal fastener strip (127). The film sheets are further sealed hermetically together (114, 244) around the periphery of each of the easily separable two distinct packages.

Description

Background and Summary of the Invention

The present invention relates generally to recloseable packages for hermetically sealing consumable products between generally opposing package side panels, and more particularly to recloseable packages for food products and the like which can be easily manufactured in tandem in which each distinct package has its own associated recloseable seal.
Certain processed meats and/or food products sold to consumers are sold in packages in which the processed meats or food products are mounted on a backing board. The freshness of these food products such as bacon, sliced luncheon meats, cheeses and the like contained within these packages depends upon the extent to which the package is vacuum packed or gas flushed and subsequently hermetically sealed. Often, the purchaser does not use the food products contained within such packages at once, but rather uses them over an extended period of time. When the initial hermetic seal of the package has been breached during opening of the package, a portion or portions of the package are often removed. In such instances, the package cannot be effectively resealed in a manner to preserve the freshness of the food products stored within. The purchaser must often repack the food products in a different suitably recloseable container.
From a manufacturing viewpoint, it is advantageous to manufacture such recloseable package in multiple formats. Accordingly, a need exists for an improved food product package which can be manufactured in tandem and later easily separated apart for transfer to a point-of-sale.
The improved package of the present invention provides a solution to the aforementioned problems and also provides significant advantages in that it has two distinct package sections each with its own hermetic seal, interior of a package recloseable seal, which extends around the entire periphery of the product so that the recloseable package is liquid tight and suitably retains within the package fluids of the products contained therein, including water, juices, oils and the like. The recloseable seal is permanently attached at its ends so that each distinct package section can be opened and closed repeatedly to remove portions of the package contents without destroying the integrity of the package. A "zipper" seal consisting of interengaging components such as rib and groove fastener elements is the preferred recloseable seal means.
The recloseable seals associated with each distinct package sections are attached to confronting faces of the packaging films. Interengaging fastener elements of the recloseable seals are provided in pairs each having a central interconnecting web and are adhered directly to the opposing package panels. Each interengaging fastener element is permanently anchored to its respective opposing package panel and is sealed at the opposite ends thereof, which decreases the possibility that the package films may tear or separate when the package section is accessed. Central web portions of the tandem package which separate the two distinct package sections preferably contain a tamper-evident feature in the form of a pair of lines or weakening extending therein which must be broken for the user to obtain access to the two package section recloseable seals.
The hermetic seal disposed around the periphery of the food product in each of the package portions of the tandem package has an easy open or peel seal portion located peripherally adjacent to the recloseable seal. The peel seal is opened with digital pull-apart forces which are also used to open the recloseable seal. The peripheral hermetic seal can maintain a vacuum, pressurized and/or gas-flushed environment within the package. The peel seal area of the hermetic seal will be formed by effecting a face-to-face seal between two plies of plastic film exterior of the product with the strength of the seal permitting separation without destruction or tearing of either ply.
The recloseable seal of the packages of this invention are attached, in tandem, to the opposing package panels at the package mouth. The separate recloseable seal interengaging fastener elements are adhered directly to the opposing package film sheets at respective package sealing flanges. The opposing package film sheets are further adhered exterior of the recloseable seal interengaging fastener elements to provide a perforated tear strip which indicates prior opening of the package. With the package seal components being disposed near the top of the individual package sections, the present invention advantageously lends itself to being efficiently manufactured in tandem.
Accordingly, it is a general object of the present invention to provide an improved recloseable package which can be easily manufactured in tandem, in a continuous length of distinct tandem packages in which each of the distinct package sections has a first recloseable seal disposed proximate to the product and a second hermetic peel seal peripherally adjacent to and interior of the recloseable seal.
Another object of the present invention is to provide a recloseable package for food products and the like having a recloseable seal and a hermetic seal disposed near an opening of the package, the hermetic seal having a peelable seal area peripherally adjacent the recloseable seal.
Yet another object of the present invention is to provide an improved method of manufacturing recloseable product packages in tandem, wherein each package has a peel seal and a recloseable seal, wherein the recloseable seal elements are attached to the first and second package film, exterior of the peel seal.
Still another object of the present invention is to provide an improved method of manufacturing recloseable product packages in tandem, wherein each package has a peel seal and a recloseable seal, wherein the recloseable seal elements are attached to the first and second package film.
These and other objects of the present invention will become more readily apparent from a reading of the following detailed description.

Brief Description of the Drawings

Figure 1 is a perspective view of a package incorporating the principles of the present invention which has been separated from a tandem package;
Figure 2 is a cross-sectional view taken along line 2-2 of Figure 1;
Figure 3 is a fragmentary cross-sectional view of the recloseable seal area of Figure 2;
Figure 4 is a cross-sectional view of a tandem package having two distinct, recloseable packages joined together by a central web portion prior to separation; and
Figure 5 is an enlarged view of the central web portion of Figure 4.

Detailed Description of the Invention

In the following detailed description, the structure of a single package 10 itself will be described initially and the construction of the tandem package 100 as manufactured will be described subsequently.
Figure 1 illustrates an embodiment of a recloseable package 10 constructed in accordance with the principles of the present invention which is manufactured in tandem in the form illustrated in Figure 4 and is later separated from its adjoining counterpart package along a center line 60 into two separate packages. The packages 10 of the present invention are particularly suitable for sealing a perishable food product, between two sheets or panels 14, 16 of flexible packaging film material. The first and second film sheets 14 and 16 forming the package 10 can be made from a variety of materials including plastic films, multi-layered laminates or co-extrusions, thermoformable materials and the like. A preferred plastic film for assembly of the packages 10 of the present invention is one which is impervious to air, oxygen or moisture.
When the package film sheets 14, 16 are formed from a laminated construction, it is desirable to use a thin, inner layer which is impervious to air, oxygen or moisture in combination with an outer layer having sufficient flexibility and desirable structural characteristics so that the laminate can function as a package sidewall. For purposes of illustration and discussion, each film sheet will be shown as a single heat-sealable lamina. In actual practice, each film sheet will likely be a laminate of two or more layers which will provide sufficient protection to the product (e.g., oxygen and moisture barriers) and which can form a hermetic, and if desired, peelable seal at thin inner surfaces. As is known in the art, a surface of vinylidene chloride polymer plastic films, such as "Saran", or of "Surlyn" ionomer or of polyvinyl chloride in contact with a surface of an ethylene vinyl acetate plastic film, can form such desired bonds.
A single package 10 has a first film sheet 14 and a second film sheet 16 which cooperatively enclose a food product 12 positioned on the first film sheet 14. The food product 12 or the like is desirably positioned on the first film sheet 14 to provide a peripheral margin 22 surrounding it. The first and second film sheets 14, 16 contact each other around the food product 12 to form a continuous edge seal 24 extending around the periphery of the food product. When vacuum-packed, the first and second film sheets 14, 16 are drawn inwardly about the food product 12 or the like to conform to the contour thereof to provide the package 10 with improved rigidity for withstanding rigorous handling during transport and retail display and the like.
As best shown in Figures 2 and 3, the package 10 has a first recloseable seal 26 which defines the package mouth 61 and is illustrated as a partial double interengaging fastener assembly 27 such as a rib and groove fastener assembly. In manufacture, the interengaging fastener assembly 27 is applied to the first film sheet 14 in the form of a double fastener strip assembly having a first, or lower, fastener element strip 29 having two, generally parallel fastener elements 32 interconnected by a integral base or web 35 extending therebetween and a pair of second, or upper, fastener element strips 28, which are interengaged or interlocked with the lower fastener elements 32 and which are not interconnected by an integral web.
The interengaging fastener assembly 27 is illustrated in Figures 1-3 as one that is particularly secure for the illustrated type of package 10, namely having a length of interconnected, formed double rib elements 34 and two similar lengths of formed groove strips 32. However, the interengaging fastener elements 32 and 34 of the recloseable seal 26 need not be limited to any particular number or type of interengaging fastener elements. Where rib and groove fastener strips are used, the ribs preferably project outwardly from the fastener element strips a sufficient distance to be securely interengaged with and held by their complementary grooves counterparts in the confronting fastener element strips. Both the recloseable seal 26 and the interengaging fastener assembly 27 can take any number of various characteristics and configurations in addition to those described herein.
In an important aspect of the present invention, the double fastener assembly 27 has a sufficient width such that the package 10, when manufactured in tandem, can be easily separated from its adjoining counterpart along a longitudinal central line 60 between the interengaging fastener elements 32, 34. Accordingly, the rear surface or the bottom interengaging fastener strip 29 and those of the upper fastener strips 29 each include transverse film sealing surfaces flanges 36, 37 which provide surfaces to adhere and seal the first and second film sheets 14, 16 to the recloseable seal interengaging fastener assembly 27. As best shown in Figure 3, the sealing flanges 36, 37 are integrally formed with their respective interengaging fastener strips 28, 29. Alternatively, the flanges 36, 37 may also be formed as separate items and separately adhered to the fastener element strips by any suitable means such as heat sealing or adhesive sealing. The sealing flanges 36, 37 of the interengaging fastener elements 32, 34 are sufficiently wide so that each flange has a large enough surface to adhere the entire width of the flange, including the fastener element, to the first and second film sheets.
Additionally, the sealing flanges 36, 37 serve as package pull flanges 90, 91 disposed adjacently exterior of the recloseable seal 26 to aid in opening the package 10. In this regard, the lower element strip 32 has a sealing flange 37 which extends up to and terminates at the package top 65, while top fastener element strip 34 has a sealing flange 36 which terminates underneath the package top 65, preferably at a position equal to the lower edge of a visually distinct colored portion 50 of the element strip sealing flange 37 at the package mouth 62. As will be described in greater detail below, the interengaging fastener assembly 27 is attached to the first and second film sheets 14, 16 by initially adhering the groove strip fastener element sealing flange 37 to a central portion 61 of the first film sheet 14. This may be accomplished by any appropriate means such as a suitable adhesive or as by heat sealing.
After the fitting of the interengaging fastener assembly 27 to the first film sheet 14, the food product 12 is positioned on the first film sheet 14. The second film sheet is placed over the first sheet and product and is adhered to the recloseable seal rib element strip longitudinal sealing flanges 36 and 37 thereof, by heat sealing, by sealing with an adhesive, or by any other suitable means. Any air present between the first and second film sheets 14, 16 when the product 12 is inserted can be evacuated and/or the product 12 gas-flushed if desired. The second film sheet 16 is further adhered to the opposite, or inner surface 38 of the groove element fastener strip web 35 and the colored portion 50 thereof.
The first and second film sheets 14, 16 are preferably dimensioned larger than the food product 12 to provide a peripheral margin 22 where they contact each other. The first and second film sheets 14, 16 are bonded together in this margin 22 to form a permanent hermetic seal 44 which substantially encircles the product. This bonding can be effected in any conventional manner, such as by heat sealing or by adhesives. It will be noted that because the double interengaging fastener assembly 27 terminates at its ends 80, it will not allow the user to separate the film sheets 14, 16 at the margin 22, and accordingly, the opening thereof will not interfere with or compromise the effectiveness of the hermetic seal 44 therein.
As best seen in Figure 1, it is desirable to make a portion of the hermetic seal 44 which is peripherally adjacent the recloseable seal 26 and the food product 12, a peelable seal 46 to allow the purchaser simple and easy access to the recloseable seal 26. The hermetic seal 44 may also be entirely of a peelable nature with the hermetic seal portion thereof having a stronger bond effected between the two films than in the peelable portion 46 so that the hermetic seal 44, for all intents and purposes, is non-peelable. It is preferable that the inner, hermetic seal 46 is a secure, yet peelable seal 46 which maintains a secure seal between the food product portion 12 and the recloseable seal 26 during handling and storage that readily can be peeled back upon the application of digital forces applied to the recloseable seal 26. After bonding the two films together, the hermetic seal 44 and the product margin 22 can be trimmed to appropriate dimensions and the package central portion 61 may be provided with one or more lines of weakening 70 disposed generally parallel to and between the recloseable seal elements 26 and preferably spaced apart therefrom at the end of the upper fastener element sealing flanges 36.
When it is desired to open a finished package, the user grips the top portion 65 of the package at the tear strip 66 and tears it off along the perforated line of weakening 70. The package mouth 62 is then accessed and the user grips the free edges of the mouth and applies digital pull apart forces to open the recloseable seal 26. The recloseable seal interengaged fastener elements 32, 34 will separate and open the package mouth 62, thereby allowing access to the inner peelable hermetic seal 46. Further exertion of digital forces will separate the peel seal portion 46 of the hermetic seal 44, thereby allowing access to the food product portion 12. Because the recloseable seal rib and groove fastener elements 32, 34 are permanently secured together at their ends 80, the likelihood of destruction of the integrity of the package 10 by the user is greatly diminished. The first and second film portions in the area of the first margin 22 will then separate and allow access to the food product 12.
Figure 4 illustrates a tandem recloseable package 100, which is the preferred form in which the packages of the present invention are manufactured. As can be seen, a first film sheet 114 is provided having a sufficient width to accommodate two package portions 110, 210 disposed on opposite sides of a central portion 105 of the first film sheet 114. An easily separable partial double fastener assembly 127 is applied to the central portion 105 of the first film sheet 114. The double fastener assembly includes a pair of opposing fastener elements strips 152, 154 interlocked together. The bottom pair of fastener elements 152 is of one-piece construction and includes a pair of fastener element strips 129, 229 disposed at opposite ends of a central, integral web 153 and interconnected thereto. A pair of separate elongated fastener elements 128, 228 having the same length as the fastener element strips 129, 229 are interlocked therewith to complete the double fastener assembly 127. The double fastener assembly 127 is then positioned on the central portion 105 of the first film sheet 114 to form the tandem package central portion and to define the two adjoining package portions 110, 210.
The first and second fastener element strips 152, 154 are preferably interengaged prior to applying the double fastener assembly 127 to the first film sheet 114. The double fastener assembly 127 may be adhered to the first film sheet 114 by any conventional sealing means, such as adhesive sealing, heat sealing or ultrasonic welding. The double fastener assembly 127 is preferably adhered to the first film sheet 114 along the entire width of its base surface 160, which serves as a double width package sealing flange 137. The upper, separate fastener element strips 128, 228 also preferably each have a base surface which is sufficiently wide to serve as package sealing flanges 136, 236.
After adhering of the double fastener assembly 150 to the first film sheet 114, the food product 112 may be positioned on each of the two distinct package portions 110, 210 on opposite sides of the double fastener assembly 127 in respective product areas. The second film sheet 116, having a width at least equal to that of the first film sheet 114, is laid over the first film sheet-food product assembly and adhered to the upper rib element fastener sealing flanges 136, 236 and to the central upper surface 162 of the groove element strip integral web 153. The second film sheet 116 is further contacted to the first film sheet 114 around the peripheral margins 122, 222 of each of the two distinct package portions 110, 210 to form individual peripheral, hermetic seals 144, 244. A portion of each of the peripheral hermetic seals 144, 244 may include a peelable bond area 146, 206 which is located interior or the recloseable seals 126, 226 and exterior of the food product 112.
After the hermetic seals 144, 244 are formed, the tandem package 100 may be provided with two lines of weakening 165, 265 in the web 153 of the double fastener strip assembly 150 such that each line of weakening is associated with a distinct package portion 110, 210. These lines of weakening are located approximately where the rib element strip sealing flanges 136, 236 terminate and the central web colored portion 170 begins. The lines of weakening 165, 265 may be applied to the tandem package 100 either prior to or after the distinct package portions 110, 210 are separated into two packages such as by cutting along a center line 190.
Importantly, the structure of the package of the present invention allows for the efficient manufacture of the same in tandem in continuous lengths which may be later trimmed to form separate tandem package units. The first film sheet 14 may be received from a continuous feed stock and the double fastener strip assembly may be applied in a continuous fashion to the first film sheet. Lastly, the film sheet product assemblies may then be covered by a second film sheet also fed from continuous fed stock and adjoining tandem packages may be separated after the peripheral hermetic seals are formed. All components of the tandem package may be supplied from a continuous feed stock to form a continuous length of packages which can be separated into individual units.
It will be seen that while certain embodiments of the present invention have been shown and described, it will be obvious to those skilled in the are that changes and modifications may be made therein without departing from the true spirit of the scope of the invention.

Claims

A method of making tandem recloseable packages for containing a product between first and second sheets of packaging material, the method comprising the steps of:
providing a first film sheet of a width sufficient to provide continuous package sections on said first film sheet, the two package sections being separated from each other by a double fastener assembly;
providing recloseable seals for each of the two package sections by way of the double fastener assembly wherein said double fastener assembly has a double fastener element strip which includes two separate, longitudinally spaced first interengaging fastener elements interconnected by an integral web, and a pair of second interengaging fastener elements which are interengaged with said two first interengaging fastener elements, said first interengaging fastener elements and said second interengaging fastener elements each having a package sealing flange disposed on opposite sides of said double fastener assembly, said first interengaging elements sealing flange including one surface of said integral web,
attaching said double fastener assembly to an interior portion of said first film sheet by adhering substantially all of said first interengaging fastener elements sealing flange to the interior portion of said first film,
placing a product onto said film sheet in said two package sections disposed on opposite sides or said double fastener assembly,
providing a second film sheet having an interior portion and attaching the interior portion of the second sheet of flexible packaging film to said double fastener assembly by adhering said second film sheet to substantially the entire outside surface of said second interengaging fastener elements to said package sealing flanges and adhering said second film sheet to an inside portion of said integral web disposed between said first and second interengaged fastener elements;
contacting said first and second film sheets with each other at a hermetic seal area adjacent to and around the periphery of each of said two products to create a hermetic seal which completely encloses each of said two products between said first and second film sheets, wherein said hermetic seal includes at least one peelable bond area adjacent to each recloseable seal of each said package section.
The method of claim 1, wherein said first and second interengaging fastener element package sealing flanges are adhered to said respective interior portions of the first and second film sheets by adhesive means.
The method of claim 1, wherein said first and second interengaging fastener elements package sealing flanges are adhered to said respective interior portions of the first and second film sheets by heat sealing means.
The method of claim 1, wherein said first and second interengaging fastener elements of said double fastener assembly includes interengaging rib and groove fastener elements.
The method of claim 1, further including the step of vacuum packing said product between said first and second film sheets.
The method of claim 1, further including the step of adhering said second film sheet to a visually distinctive portion of said double fastener assembly first interengaging fastener element strip integral web.
The method of claim 1, further including the step of forming lines of weakening in said double fastener assembly first interengaging fastener element strip integral web parallel to and exterior of said interengaging fastener elements.
The method of claim 1, further including the step of separating said tandem recloseable package along said double fastener assembly first interengaging fastener element strip integral web.
The method of claim 1, further including the step of adding a visually distinctive portion to said double fastener assembly first interengaging element strip integral web.
A method of making a recloseable package in tandem, comprising the steps of:
providing a first package panel from a continuous feed stock thereof, the first package panel having a width sufficient to provide two package portions separated by a central web portion;
providing a continuous length of a double fastener assembly, wherein the double fastener assembly includes a first double fastener element strip having a preselected width, the first double fastener element strip having two fastener elements disposed along opposite sides of said double fastener element strip width, the two fastener elements of said first double fastener element strip being connected by an integral web, said double fastener assembly further including two separate second fastener element strips interengaged with said first fastener elements each of said second fastener elements having a package sealing flange disposed on a side thereof opposite said first fastener elements;
adhering said double fastener assembly to said first package panel at said central web portion;
providing a second package panel from a continuous feed stock, the second package panel having a width approximately equal to said first package panel width; and
adhering said second package panel to said first package panel, the second fastener element sealing flanges and a portion of said first fastener element integral web so as to provide each of the two package portions with a permanent hermetic seal around part of the perimeter of each of said two package portions and a peelable hermetic seal around the remainder of the perimeter of each of said two package portions.
The method of claim 10, including the step of providing two lines of weakening in said first fastener element strip integral web, each of the two lines of weakening being associated with a respective package portion.
The method of claim 10, further including the step of separating said tandem recloseable package into two separate recloseable packages by separating said two package portions from each other along a centerline of said first double fastener element integral web.
The method of claim 10, further including the step of applying a visually distinct colored portion to said first double fastener element integral web, the visually distinct colored portion extending generally along the centerline of said first fastener element strip integral web and extending a preselected distance toward said fastener elements.
The method of claim 10, further including the steps of adding a product to each product portion of said tandem package and vacuum packing said product between said first and second package panels.
A tandem recloseable product package, comprising:
a base film sheet having a width sufficient to provide two recloseable package sections;
a double interengaging fastener assembly disposed in approximately the center of the base film sheet, the two recloseable package sections being disposed on opposite sides of said double interengaging fastener assembly, the double interengaging fastener assembly including a first fastener element strip having elongated fastener elements disposed on opposite sides of and being interconnected by a integral web and two second fastener element strips interengaged with said first fastener strip elongated fastener elements, each of said second fastener element strips including a package sealing flange on its opposite surface, said first fastener element strip also including a package sealing flange on its base, said double interengaging fastener assembly being adhered to said base film sheet;
a cover film sheet adhered to said second fastener element strip sealing flanges and said first fastener element strip integral web, the cover film sheet further being adhered to said base film sheet around the periphery of each of said two recloseable package sections so as to form a hermetic seal which completely encloses each of said package sections, the hermetic seal including at least one peelable bond area interior of and adjacent to each package section recloseable seal, and
said tandem recloseable package being adapted to be longitudinally separated between and spaced from said recloseable seals into two separate recloseable packages wherein each of the two recloseable packages possesses a recloseable seal and a hermetic seal interior of said recloseable seal.
The tandem recloseable package of claim 15, wherein said first fastener element strip integral web includes a visually distinctive portion exterior of said recloseable seals.
The tandem recloseable package of claim 15, wherein said first fastener element strip integral web includes a pair of parallel spaced-apart lines of weakening which define tear strips associated with each of said two recloseable package sections.
The tandem recloseable package of claim 15, wherein the peelable bond area of said hermetic seal is formed by adhesive means.
The tandem recloseable package of claim 15, wherein said peelable bond area of said hermetic seal is formed by heat sealing means.
The tandem recloseable package of claim 15, wherein said first and second interengaging fastener elements include interengaging rib and groove elements.
The tandem recloseable package of claim 15, wherein said package is for enclosing perishable food products.
A recloseable, flexible, tandem package for hermetically sealing a meat food product in two distinct, easily separable product packages, each of the two distinct packages having its own distinct recloseable seal to permit periodic access to the package after initial opening of said package, comprising, in combination:
two opposing, flexible, oxygen-impermeable package sidewalls, the package sidewalls including first and second sheets of package film contacting each other and bonded together to define said two distinct packages hermetically bonded at three sides and having a fourth side containing a package mouth portion, double continuous recloseable fastener means forming two recloseable seals, each one of said two recloseable seals being associated with a distinct package of said two distinct packages, the double continuous fastener means including a double strip of first interengaging fastener elements interconnected by an integral web, the first interengaging fastener elements including two single strips of second interengaging fastener elements interlocked therewith, the first interengaging fastener elements being adhered to said first film sheet proximate to two access edges of said two packages, said double strip of first interengaging fastener elements including an integral web which combines with said first interengaging fastener elements to form a first seal flange, said first film sheet being bonded to the first seal flange of said first interengaging fastener elements, said second film sheet being bonded to the second seal flanges of said second interengaging fastener elements, said first and second film sheets further being bonded to each other at said package mouth portion to form a hermetic peelable seal adjacent to and exterior of said recloseable fastener means, said double continuous fastener means including means for separating said tandem package into two packages.
The recloseable package of claim 22, wherein said meat food product is a perishable bacon meat product.
The recloseable package of claim 22, wherein said meat food product is vacuum packed between said first and second film sheets.
The recloseable package of claim 22, wherein said first and second interengaging fastener element package sealing flanges are bonded to said first and second film sheets by adhesive means.
The recloseable package of claim 22, wherein said first and second interengaging fastener element package sealing flanges are bonded to said first and second film sheets by heat sealing means.
The recloseable package of claim 22, wherein said double strip integral web includes a pair of parallel, spaced-apart lineS of weakening exterior of and parallel to said interengaging fastener elements which define tear strips associated with each of said two recloseable package sections