Tamper-evident tandem recloseable package and method of making same

Abstract: A flexible tandem package (100) which can be readily separated into two, distinct recloseable packages (110, 210) and the method for making the same is disclosed. The package includes first and second sheets (116, 114) sealed to opposite surfaces of a double recloseable seal fastener assembly (127). The film sheets (116, 114) are further sealed hermetically together around the periphery (144, 244) of each of the easily separable two distinct packages. Parallel lines of weakening (170, 270) disposed in the central portion of the recloseable seal fastener assembly provide tamper-evident tear strips for each of the two distinct packages (110, 210).

Description: The present invention relates generally to tandem packages comprising two package sections and to methods for manufacturing such packages. The invention relates more particularly to recloseable packages for food products and the like, in which each distinct package section of a tandem package has its own associated recloseable seal. The freshness of certain processed meats and/or food products such as bacon, sliced luncheon meats, cheeses and the like depends upon the extent to which the food product 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. US-A-4246288 describes a tandem package according to the preamble of claim 14, comprising two package sections which are separated by a recloseable seal comprising a double fastener element strip having two fastener elements interconnected by an integral web, and a pair of single unconnected fastener element strips engaging respective fastener elements of the double fastener element strip. The single fastener element strips and the double fastener element strip are attached to first and second thermoplastic sheets, respectively. The first thermoplastic sheet is attached to the integral web of the double fastener element strip between its fastener elements. The package sections are separable along a center line of the tandem package which also has two parallel score lines or lines of perforations extending at each side of the centre line between the single fastener element strips. US-A-4923309 describes a tandem package comprising two package sections which are joined by a double recloseable seal comprising two double fastener element strips which have integral webs which are joined together between the fastener elements of the two strips. The package sections can be separated along a center line extending through the region where the two webs are joined. Lines of weakening or perforations are provided in the webs to each side of the center line. Each package section has a peel seal internally of its reclosure seal. The packages of the present invention are defined in claim 14, and the methods of making them, in claims 1 and 9, to which reference should now be made. Optional features of the invention are given in the dependent claims. The package of the present invention provides a solution to the above mentioned problem in that it has two distinct package sections each with its own hermetic seal, internally 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 section 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 of 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 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. Accordingly, it is a general object of the present invention to provide an improved recloseable package which can be easily manufactured in a continuous length of distinct tandem packages in which each of the two package sections thereof has its own recloseable seal. Another object of the present invention is to provide a recloseable package which can be easily manufactured in a tandem package assembly wherein each of the tandem packages has a hermetic seal surrounding the packaged product, a recloseable seal externally of the hermetic seal and a permanently sealed tear strip externally of the recloseable seal. A further object of the present invention is to provide a tandem package having two distinct package sections containing a food product portion or the like, each package having a separate recloseable seal associated with each food product portion, the two distinct package section6being joined by a package central web portion having lines of weakening associated therewith which define distinct package section tear strips. 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 films. Yet another object of the present invention is to provide an improved method of making recloseable packages in tandem, wherein a double fastener assembly is adhered to confronting surfaces of opposing package panels so as to provide each distinct package with its own tamper-evident tear strip. These and other objects of the present invention will become more readily apparent from a reading of the following detailed description of an embodiment of the invention, described with reference to the drawings. Brief Description of the Drawings Figure 1 is a perspective view of a package incorporating the principles of the present invention, the package having 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 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 Figures 4 and 5 illustrate an embodiment of a recloseable package 100 constructed in accordance with the principles of the present invention which is manufactured in tandem and is separated after manufacture along a center line 103 into two distinct counterpart packages 110, 210. The first and second film sheets 116 and 114 which are combined to form the package 100 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 100 and for use in the method of the present invention is one which is impervious to air, oxygen or moisture. When the package film sheets 116, 114 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" in contact with a surface of an ethylene vinyl acetate plastic film, or of a "Surlyn" ionomer in contact with a "Surlyn" ionomer mixture or of a polyethylene in contact with a polyethylene mixture can form such desired bonds. The tandem package 100 is assembled by advancing a package first film sheet 116 having a width W t sufficient to accommodate two separate product portions 112, 212 in two distinct package sections 110, 210. An easily separable two-piece interengaged fastener assembly 127 is applied to the central portion of the first film sheet 116 to form a central web portion 105 of the tandem package 100 and which defines the adjoining two distinct package sections 110, 210. The interengaged fastener assembly 127 includes an elongated first, or lower, fastener element strip 130, which contains two parallel fastener elements, shown as rib elements 132, 232 extending along the opposite ends thereof. The two first fastener elements 132, 232 are interconnected by a central first fastener element strip integral web 150 so that the first element strip 130 may be extruded as a continuous length. An elongated second, or upper, fastener element strip 131 also contains two parallel fastener elements, illustrated as groove elements 134, 234 which extend along the opposite ends thereof. Similar to the first rib elements 132, 232, the second groove elements 134, 234 are interconnected by a central second fastener element strip integral web 152 which also permits the second fastener element strip to be extruded in a continuous length. Although illustrated as having double ribs and double grooves, the first and second fastener elements need not be limited to any particular number of interengaging fastener elements or limited in the orientation of the rib and groove elements, i.e., upper or lower. Rather, it is preferred that the fastener elements have a sufficient width and depth to be securely interengaged when assembled to withstand the rigorous handling which commonly occurs during transport, retail display and the like without separating. Additionally, the first and second fastener elements of the double fastener assembly 127 can take any number of various characteristics and configurations in addition to the rib and groove configurations illustrated herein. The first and second fastener element strips 130, 131 art preferably interengaged prior to applying the double fastener assembly 127 to the first film sheet 116. The interengaged fastener elements of the first and second integral webs 150, 152 provide each of the two distinct package sections 110, 210 with a recloseable seal 126, 226. Additionally, the first and second webs 150, 152 have a preselected width between the recloseable seal fastener elements which is sufficient to provide a tamper-evident tear strip 160, 260 for each distinct package section as more fully described below. The width of the opposite sides of each of the first and second webs 150, 152 is also wide enough to serve as respective package sealing flanges 135a, 135b which provide the double fastener assembly 127 with respective upper and lower surfaces to adhere the first and second film sheets 116, 114 together. Because the first and second integral webs 150, 152, have respective confronting film sheet portions attached thereto they are thick enough to serve as pairs of package pull flanges 136, 137 and 236, 237 associated with their respective distinct package sections 110, 210. In this regard, the outside surfaces of the two sealing flanges 136, 137 of one package section 110 are adhered respectively to the first and second film sheets, as are the sealing flanges 236, 237 of the other package section 210. The double fastener assembly 127 may be applied as a unit to the first or bottom film sheet 116 in the form of a continuous strip and trimmed, at a convenient time during the manufacturing process, to define the eventual finished package mouth. The separate rib and groove fastener elements 132, 232 and 134, 234 are permanently attached at the ends of the two package section recloseable seals 126, 226 so that the fastener material is not wasted in the trifling of the packages and so that when the recloseable seal is opened, the purchaser cannot disrupt the integrity of the interior hermetic seals 144, 244 of the two distinct package sections 110, 210. After the double fastener assembly 127 is fitted onto the bottom film sheet 116, and the ends thereof are attached together, two food product portions 112, 212, such as sliced luncheon meat or the like, are positioned on the bottom film sheet 116 in the two distinct package sections 110, 210. The top film sheet 114 is brought into contact with the two food product portions 112, 212, the bottom film sheet 116 and the double fastener assembly second fastener strip 131, and a vacuum is applied therebetween. A first permanent, hermetic seal 144, 244 is formed in the margins 122, 222 surrounding each food product 112, 212 in the two distinct package sections 110, 210. These outer hermetic seals 144, 244 surround each food product portion 112, 212 on three sides. The hermetic seals 144, 244 may be completely extended around the periphery of the two food product portions 112, 212 by forming an inner peelable hermetic seal 146, 246 in each distinct package section 110, 210 internally of the recloseable seals 126, 226 and externally of the food product portions 112, 212. It is preferable that the inner hermetic seals 146, 246 are secure, yet peelable hermetic seals which maintain a secure seal during handling and storage that can be peeled back upon the application of digital forces applied to the second recloseable seals 126, 226. The top film sheet 114 may then be adhered to the second sealing flange 135b of the double fastener assembly 127, thereby sealing the two product portions 112, 212 into their respective distinct package sections 110, 210. Means for separating and gaining access to the recloseable seals 126, 226 of the two package section as well as means for indicating prior opening of the package sections are illustrated as parallel lines of weakening 170, 270, which extend longitudinally through the package central web portion 105 between the recloseable seals 126, 226 of the two package sections. The lines of weakening 170, 270 serve as a component of a tamper-evident feature which indicates prior access to the recloseable seals 126, 226. In this regard, it is preferable that the two opposing first and second integral webs 150, 152 are adhered together along the tandem package center line 103, such as by adhesive means, heat sealing or ultrasonic welding. The lines of weakening can be administered to the package central web portion 105 in any suitable manner such as by perforations or scoring. Additionally, either one or both of the first and second fastener element strips 130, 131 of the double fastener assembly 127 may be provided with a visually distinctive layer such as a relatively bright red layer 190 which is either co-extruded with the fastener element strip, such as the first, or bottom fastener element strip 130, or separately adhered thereto. The colored layer 190 serves to provide each of the two package sections 110, 210 with a visually distinctive appearance when either of the lines of weakening 170, 270 are broken. In this regard, the lines of weakening 170, 270 are exterior of the recloseable seals 126, 226 and interior of the seal between the first and second integral webs 150, 152. After assembly of the first and second film sheets 114 and 116 to the double fastener assembly 127, the two distinct package sections 110, 210 may be separated from each other along a longitudinal line 103 extending through the center of the package central web portion 105 between the recloseable seals 126, 226. When it is desired to open a finished package, the user grips the package and tears off the tear strip 160 along the line of weakening 170 and exposes a package mouth 195 to gain access to the inner second recloseable seal 126. The excess material of the first and second integral webs 150, 152 extending from the respective fastener elements 132, 134 up to the package mouth 195 serves to provide package pull flanges 136, 137 of substantially similar length which are gripped by the user for applying digital pull apart forces thereto in order to open the recloseable seal 126 of the package section 110. The recloseable seal interengaged fastener elements 132, 134 will separate and open to form a package section mouth 195, thereby allowing access to the inner peelable hermetic seal 146 and the food product portion contained thereby. Figures 1-3 illustrate a package 10 which has been removed from its counterpart package by separating the two along the central web portion center line 3. The top and bottom film sheets 14, 16 cooperatively enclose a food product portion 12 positioned on the first film sheet 16. The food product 12 or the like is desirably positioned on the first film sheet 16 to provide a peripheral margin 22 surrounding it. The 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. The package 10 has a first recloseable seal 26 disposed above a second, inner peelable hermetic seal 46. The recloseable seal 26 includes a pair of fastener strips 28, 29 with interengaging fastener elements 32, 34 adhered to confronting faces of the first and second film sheets 16, 14. The rear surfaces of the interengaging fastener strips 28, 29 each include film sealing surfaces 35a,35b which extend transversely to the fastener strips 28, 29 and which are sealed to the package film sheets 16, 14 by any suitable means such as heat sealing or adhesive sealing. The sealing flanges 35a, 35b of the interengaging fastener elements 28, 29 are sufficiently wide so that each flange has a large enough surface to adhere to the package film sheets and to serve as package pull flanges 36, 37 to assist the user in separating the recloseable seal fastener elements of the finished package. The two sealing flanges 35a, 35b extend up to and terminate at the package top 65. A line of weakening 70 is disposed parallel to and interior of the package top 65 and defines a tear strip 60 extending at or slightly exterior of the line of weakening 70. The two sealing flanges 135a, 135b may be sealed together along the tear strip 60. Either or both of the sealing flanges 135a, 135b may include a colored layer, shown as a red portion, in the package area above the line of weakening 70. To open the package 10, the user grips the tear strip 60 along the package top 65 and tears it off along the line of weakening 70. The package mouth 62, which is formed by the opposing fastener element sealing flanges 35a, 35b is accessed and the user grips the free edges of the pull flanges 36, 37 and applies digital pull apart forces to open the recloseable seal 26. Further exertion of digital forces will separate the peel seal portion 46 of the hermetic seal 44, thereby allowing access to the package contents 12. The recloseable seal 26 is permanently secured together at its ends 80 so that the likelihood of destruction of the integrity of the package 10 is greatly diminished. Manufacture of the packages of the present invention is greatly simplified in that the three major package components, namely, the first or bottom package film 116, the double fastener assembly 127 and the second or covering package film 114 can be supplied to one or more package assembly stations in a continuous fashion to assemble, if desired, a continuous length of tandem packages which can then be separated into separate tandem packages 100 and further separated into individual packages.

Claims: A method of making tandem packages (100) comprising two tamper-evident recloseable package sections (110, 210), each package section containing a product between first and second sheets (116, 114) of packaging material, the method comprising the steps of: providing a first film sheet (116) of a width sufficient to provide two continuous package sections on the first film sheet, the two package sections being separated from each other by a first film sheet central web portion; applying a double fastener strip assembly (127) to the first film sheet central web portion, wherein the double fastener strip assembly has a first double fastener element strip (130) having two separate first interengaging fastener elements (132, 232) interconnected by a first integral web (150), and a second double fastener element strip (131) having two separate second interengaging fastener elements (134, 234) interconnected by a second integral web (152), the second interengaging fastener elements being interengaged with said first interengaging fastener elements, the first and second integral webs (150, 152) providing respective first and second flange sealing surfaces (136, 236, 137, 237) disposed on the outer sides of their respective integral webs (150, 152), the double fastener strip assembly (127) being adhered to the first film sheet central web portion by the entire first flange sealing surface (136, 236), the interengaged first and second fastener elements (132, 232, 134, 234) providing a recloseable seal (126, 226) for each of the two package sections; placing a product portion onto the first film sheet (116) in each of the two package sections (110, 210) on opposite sides of the double fastener strip assembly (127); providing a second film sheet (114) having a width at least equal to that of the first film sheet (116) and attaching the second film sheet by adhering the entire second flange sealing surface (137, 237) to the second film sheet; contacting the first and second film sheets (116, 114) with each other at a hermetic seal area (122, 222) adjacent to and around the periphery of each of the two products (112, 212) to create a hermetic seal (144, 244) of each of the two package sections, the respective hermetic seals completely enclosing the two products (112, 212) between the first and second film sheets (116, 114), wherein each hermetic seal includes at least one peelable bond area (146, 246) adjacent to and inwardly of the recloseable seal (126, 226) of each package section; and forming two lines of weakening (170, 270) between the recloseable seals (126, 226), each of the lines of weakening defining a tear strip associated with a respective one of the two package sections (110, 210), the two lines of weakening passing through the first film sheet central web portion and the first and second fastener element strip integral webs (150, 152) to the exterior of the recloseable seals (126, 226); wherein the first and second integral webs (150, 152) are adhered together between the lines of weakening (170, 270) at least to each side of a longitudinal center line (103) of the package disposed between the two lines of weakening. A method according to claim 1, wherein the first and second integral web package flange sealing surfaces (136, 236, 137, 237) are adhered to the first and second film sheets (116, 114) by adhesive means. A method according to claim 1, wherein the first and second integral web package flange sealing surfaces (136, 236, 137, 237) are adhered to the first and second film sheets (116, 114) by heat sealing means. A method according to any preceding claim, wherein the first and second double fastener element strips (130, 131) include interengaging rib and groove fastener elements (132, 232, 134, 234). A method according to any preceding claim, including the step of vacuum packing the product between the first and second film sheets (116, 114). A method according to any of claims 1 to 4 including the step of gas flushing each of the two package sections (110, 210). A method according to any preceding claim, including the step of separating the tandem package (100) into two separate package sections (110, 210) along the longitudinal line (103) of the double fastener assembly (127). A method according to any preceding claim, including the step of forming a visually distinctive portion (190) in a central portion of the double fastener assembly (127). A method of making tandem packages (100) comprising two recloseable package sections (110, 210), the method comprising the steps of: providing a continuous length of a first package panel (116), the first package panel having a width sufficient to provide two counterpart package portions separated by a first package panel central web portion; providing a continuous length of double fastener assembly (127), the double fastener assembly having a first double fastener strip (130) having two interengaging fastener elements (132, 232) disposed along opposite sides of and interconnected by a first integral web (150), the double fastener assembly further having a second double fastener strip (131) having two interengaging fastener elements (134, 234) disposed along opposite sides of and interconnected by a second integral web (152), the first and second interengaging element strips being interengaged with each other, each of the first and second fastener elements having a flange sealing surface (136, 236, 137, 237) disposed on a side opposite that of the respective interengaging fastener elements (132, 232, 134, 234) to provide two recloseable seals (126, 226) in the first package panel central web portion; adhering the continuous length of double fastener assembly to the continuous first package panel (116) along the entire width of the first fastener element flange sealing surface (136, 236); providing a continuous length of a second package panel (114), the second package panel having a width approximately equal to the first package panel width; adhering the second package panel continuous length to the first package panel continuous length so as to provide each of the two counterpart package portions with a permanent hermetic seal (122, 222) around part of its perimeter and a peelable hermetic seal (146, 246) around the remainder of its perimeter, and adhering the second package panel continuous length to the second fastener element flange sealing surface (137, 237); applying two lines of weakening (170, 270) to the double fastener assembly, each of the two lines of weakening being disposed generally parallel to and between the two recloseable seals (126, 226); and, severing the continuous lengths of the first and second package panels at preselected intervals to define individual tandem, recloseable packages; wherein the first and second integral webs (150, 152) are adhered together between the lines of weakening (170, 270) at least to each side of a longitudinal center line (103) of the package disposed between the two lines of weakening. A method according to claim 9, further including the step of separating the tandem packages (100) into two separate recloseable packages by separating the two counterpart package portions along the longitudinal center line (103). A method according to claim 9 or 10, including the step of applying a visually distinct portion (190) to one of the first and second double fastener integral webs (150, 152), the visually distinct portion extending generally along the longitudinal center line (103) of the double fastener assembly and proximate to the two lines of weakening (170, 270). A method according to any of claims 9 to 11, including the steps of adding a product (112, 212) to each counterpart product portion of the tandem package (100) and vacuum packing the product between the first and second package panels (114, 116). A method according to any of claims 9 to 11, including the step of gas flushing each counterpart product portion (110, 210) of the tandem package (100). A tandem package (100) comprising two recloseable product package sections (110, 210), each package section having a tamper-evident tear strip associated therewith, the tandem package comprising: a base film sheet (116) having a width sufficient to provide two recloseable package sections (110, 210); an elongate double fastener assembly (127) extending longitudinally of the film base sheet in approximately the center of the base film sheet, the double fastener assembly including a first, lower fastener element strip (130) having a pair of elongate first interengaging fastener elements (132, 232) disposed on opposite sides thereof, the pair of first interengaging fastener elements being interconnected by a first integral web (150) and a second, upper fastener element having a pair of elongate second fastener elements (134, 234) interengaged with respective ones of the pair of first fastener elements (132, 232); a cover film sheet (114) adhered to the second fastener elements so as to form two recloseable seals (126, 226) associated with respective ones of the recloseable package sections (110, 210), the cover film sheet (114) further being adhered to the base film sheet (116) around the periphery of each of the two recloseable package sections (110, 210) so as to form a hermetic seal (144, 244) which completely encloses each of the package sections (110, 210); the tandem package including two elongate lines of weakening (170, 270) disposed generally parallel to and between the two package section recloseable seals (126, 226), the two elongate lines of weakening defining two package section tear strips; and the tandem recloseable package being adapted to be longitudinally separated along a longitudinal center line (103) lying between and spaced from the recloseable seals (126, 226); characterised in that: the second fastener elements (134, 234) are interconnected by a second integral web (152) along opposite sides of which the second fastener elements are disposed to form a second, upper fastener element strip (131); the first and second fastener element strips (130, 131) provide respective first and second flange sealing surfaces (136, 236, 137, 237) disposed on the outer sides of their respective integral webs (150, 152); the hermetic seal includes at least one peelable bond area (146, 246) interior to and adjacent to each of the two package section recloseable seals; the first and second integral webs (150, 152) are adhered together between the lines of weakening (170, 270) and at least to each side of the longitudinal center line (103); and the lines of weakening (170, 270) pass through the first film sheet central web portion (105) and the first and second fastening element strip integral webs (150, 152). A package according to claim 14, wherein the double fastener assembly (127) includes a visually distinctive portion (190). A package according to claim 14 or 15, wherein the base and cover film sheets (116, 114) are of oxygen impermeable material. A package according to claim 14, 15 or 16, wherein the peelable bond area (146, 246) of the hermetic seal (144, 244) is formed by adhesive means. A package according to claim 14, 15 or 16, wherein the peelable bond area (146, 246) of the hermetic seal (144, 244) is formed by heat sealing means. A package according to any of claims 14 to 18, wherein the first and second interengaging fastener elements include interengaging rib and groove elements (132, 134, 232, 234). A package according to any of claims 14 to 19, wherein the integral webs (150, 152) of the double fastener assembly (127) are bonded to the base and cover film sheets (116, 114) by adhesive means. A package according to any of claims 14 to 19, wherein the integral webs (150, 152) of the double fastener assembly (127) are bonded to the base and cover film sheets (116, 114) by heat sealing means. A package according to any of claims 14 to 21, which is for enclosing perishable food products (112, 212). A package according to claim 22, wherein a food meat product (112, 212) is vacuum packed in each package section (110, 210) between the first and second film sheets (116, 114). A package according to any of claims 15 to 23, wherein the visually distinctive portion is disposed between the two lines of weakening (170, 270).

Inventors: HUSTAD GERALD O, LUCKE DONALD E, HUSTAD, GERALD O., LUCKE, DONALD E.
Applicants: MAYER OSKAR FOODS, OSCAR MAYER FOODS CORPORATION
Application year: 1991
Main classification: B65D33
IPC codes: B65B61, B31B1, B65D33, B65D77