Patent Application
20150056342
Color is an important characteristic of packaged meat products that affects merchantability. Consumers typically judge the freshness of meat by the presence of the bright red oxymyoglobin pigment. Oxymyoglobin in fresh meat decreases with time during storage as it changes to metmyoglobin. Although the pigment loss is primarily cosmetic in nature, it has serious economic consequences. For example, consumers in search of the freshest looking cuts avoid purchasing meat containing even small amounts of brown metmyoglobin. The unsold product that results from oxymyoglobin loss in red meat costs the food industry an estimated $700 million dollars annually.
To provide the consumer-preferred red color, meat is commonly packaged in a modified atmosphere package (“MAP”), where it is maintained in a sealed pocket containing an atmosphere that is different than ambient air. Packaging fresh meat products with an inert gas atmosphere has been found to be an acceptable way to preserve the meat product and provide desirable aging after shipment from a processing facility to a retail outlet. However, one problem associated with modified atmosphere packages available today is that large areas of the meat surface can contact an upper barrier film. In such instances, the contacted meat surface becomes discolored as the meat pigment converts into the metmyoglobin state.
Further, lidding materials composed of two films (a highly permeable inner film and a high barrier outer film) are known in the industry. These prior art lidding films include a small gap positioned between the inner and outer films, filled with a modified atmosphere gas. The high permeability of the inner film allows the modified atmosphere gas to permeate from the package interior into the gap and then permeate back through the inner film to transfer desired gas molecules (i.e., oxygen) to the contacted meat surface. The prior art films therefore can allow a meat product to be in full contact with the permeable inner lidding film without discoloration. Such a system works well for packages with a profile of up to about 0.5 inches above the flange of a support member. Packaging products with a higher profile often results in the loss of the gap between the films. Particularly, either too much tension from the product forces the films together or overstretches the inner film causing tearing, which makes it impossible to maintain the gap between the films.
The presently disclosed subject matter addresses the shortcomings in the prior art and discloses a package that allows all or substantially all of the surface of a red meat product to be in contact with a desired gas concentration in high profile geometries. In addition, the disclosed package ensures that large amounts of the meat surface are not in contact with the package barrier lidding film, resulting in discoloration.
The description of the presently disclosed subject matter is discussed herein primarily in relation to meat products. However, it should be appreciated that the presently disclosed subject matter can also be applied to other oxygen-sensitive foodstuffs and articles to be packaged.
In some embodiments, the presently disclosed subject matter is directed to a package comprising a support member and a thermoformed lidding film. The support member comprises a lip extending around the perimeter of the support member. The lidding film comprises a flange extending around the perimeter of the lidding film and a dome. Specifically, the dome comprises a top and sides that are interconnected to define a cavity and a plurality of inwardly-facing ridges disposed on the dome top, sides, or both. The lidding film flange is hermetically sealed to the lip of the support member to create an enclosed space.
In some embodiments, the presently disclosed subject matter is directed to a method of packaging an oxygen-sensitive product. Particularly, the method comprises providing a support member comprising a lip extending around the perimeter of the support member. The method further comprises providing a thermoformed lidding film comprising a flange and a dome. The flange extends around the perimeter of the lidding film. The dome comprises a top and sides that are interconnected to define a cavity and a plurality of inwardly-facing ridges disposed on the top, sides, or both. The method further comprises providing an oxygen-sensitive product and positioning the product on the support member. In addition, the method comprises hermetically sealing the lidding film flange to the support member lip such that the product is positioned within the cavity and all contact between the lidding film and the product occurs at the ridges.
In some embodiments, the presently disclosed subject matter is directed to a method of blooming an oxygen-sensitive product. The method comprises providing a support member comprising a lip extending around the perimeter of the support member. The method further comprises providing a thermoformed lidding film comprising a flange extending around the perimeter of the lidding film and a dome. The dome comprises a top and sides that are interconnected to define a cavity and a plurality of inwardly-facing ridges disposed on the top, sides, or both. The method comprises providing an oxygen-sensitive product and positioning the product on the support member. The method further comprises inserting a desired atmosphere into the cavity of the package prior to sealing the lidding film to the support member. In addition, the method comprises hermetically sealing the lidding film flange to the support member lip such that all contact between the lidding film and the product occurs at the ridges. Continuing, the package is either wrapped in a barrier overwrap, positioned within a gas barrier container, and/or provided with at least one opening covered by a removable member in the support member or the lidding film. The method further comprises removing the overwrap, gas barrier container, or removable member at a desired time to initiate blooming of the product.
a is a perspective view of one embodiment of the presently disclosed package.
b is a sectional view taken through line 1b-1b of
c is a perspective view of one embodiment of the disclosed package enclosed by a barrier overwrap.
d is a perspective view of one embodiment of the disclosed package enclosed in a gas barrier container.
a is a top plan view of one embodiment of a disclosed support member.
b is a fragmentary view of one embodiment of a disclosed support member.
c is a fragmentary view of one embodiment of the support member of
d is one embodiment of a ridged support member in accordance with the presently disclosed subject matter.
e is one embodiment of a package in accordance with some embodiments of the presently disclosed subject matter.
a is a perspective view of one embodiment of a lidding film of the disclosed package.
b is a sectional view taken through line 3b-3b of
c is a sectional view of one embodiment of the disclosed lidding film.
a-4c are sectional views of several embodiments of products positioned on a support member.
a-5c are perspective views of three embodiments of positioning a product on a support member.
d is a segmented view of one embodiment of a product positioned on a support member.
e is a perspective view of one embodiment of positioning a lidding film on a support member.
f is a perspective view of one embodiment of a package with a lidding film sealed to a support member.
The presently disclosed subject matter is directed to a package that allows the entire surface (or substantially the entire surface) of an oxygen-sensitive product (such as fresh red meat) to be in contact with a desired internal gas concentration. In addition, the disclosed package ensures that large amounts of the product surface are not in contact with the packaging materials, which prevents discolored product areas and provides favorable display of the packaged product.
While the following terms are believed to be understood by one of ordinary skill in the art, the following definitions are set forth to facilitate explanation of the presently disclosed subject matter.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently disclosed subject matter pertains. Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently disclosed subject matter, representative methods, devices, and materials are now described.
Following long-standing patent law convention, the terms “a”, “an”, and “the” can refer to “one or more” when used in the subject specification, including the claims. Thus, for example, reference to “a package” includes a plurality of such packages, and so forth.
Unless otherwise indicated, all numbers expressing quantities of components, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the instant specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.
As used herein, the term “about”, when referring to a value or to an amount of mass, weight, time, volume, concentration, or percentage can encompass variations of, in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments to ±0.1%, from the specified amount, as such variations are appropriate in the disclosed system and methods.
As used herein, the phrase “abuse layer” refers to an outer film layer and/or an inner film layer, so long as the film layer serves to resist abrasion, puncture, and other potential causes of reduction of package integrity, as well as potential causes of reduction of package appearance quality. An abuse layer can comprise any polymer, so long as the polymer contributes to achieving an integrity goal and/or an appearance goal. In some embodiments, an abuse layer can comprise polymers having a modulus of at least 107 Pascals, at room temperature. In some embodiments, an abuse layer can comprise (but is not limited to) polyamide and/or ethylene/propylene copolymer, polypropylene; in some embodiments, nylon 6, nylon 6/6, and/or amorphous nylon.
The term “all” as used herein (such as the phrase “all contact”) refers in some embodiments to about 100%. However, the term “all” can refer to amounts of about 80% and higher (i.e., 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99%).
As used herein, the term “antifog film” refers to a polymeric film having at least one surface with properties that have been modified or adapted to have antifog characteristics. That is, the film has a tendency to reduce or minimize the negative effects of moisture condensation. For example, an antifog film can incorporate effective amounts one or more antifog agents in the polymeric film resin before forming the resin into a film. Further, the antifog film can be a laminated film formed from two films laminated together, in which one film has antifog characteristics and the other film does not have antifog characteristics. Also, the antifog film can be multilayered, in which case the antifog agent can be incorporated in one or more of the layers of the film, such as in one or more of the outer layers of the film. The antifog agent can be absent from (i.e., not incorporated in) one or more (or all) of the internal layers of the film. Effective amounts of antifog agent in a film layer include from about 0.5% to about 12%, from about 1% to about 10%, from about 1.5% to about 8%, and from about 2% to about 6%, based on the total weight of the layer. Useful amounts of antifog agent in the film include less than about each of the following: 10%, 5%, 4%, 3%, and 2%, based on the total weight of the film.
As used herein, the term “barrier layer”, as applied to films and/or film layers, refers to the ability of a film or film layer to serve as a barrier to gases and/or odors. Examples of polymeric materials with low oxygen transmission rates useful in such a layer can include: ethylene/vinyl alcohol copolymer (EVOH), polyvinylidene dichloride (PVDC), vinylidene chloride copolymer such as vinylidene chloride/methyl acrylate copolymer, vinylidene chloride/vinyl chloride copolymer, polyamide, polyester, polyacrylonitrile (available as Barex™ resin), or blends thereof. Oxygen barrier materials can further comprise high aspect ratio fillers that create a tortuous path for permeation (e.g., nanocomposites). Oxygen barrier properties can be further enhanced by the incorporation of an oxygen scavenger, such as an organic oxygen scavenger. In some embodiments, metal foil, metallized substrates (e.g., metallized polyethylene terephthalate (PET), metallized polyamide, and/or metallized polypropylene), and/or coatings comprising SiOx or AlOx compounds can be used to provide low oxygen transmission to a package. In some embodiments, a barrier layer can have a gas (e.g., oxygen) permeability of less than or equal to about 500; in some embodiments, less than about 100; in some embodiments, less than about 50; and in some embodiments, less than about 25 cc/m2/24 hrs/atm at 73° F. (ASTM D3985).
The term “barrier overwrap” as used herein refers to a material formed from a barrier film or material that can cover the external surface of all or part of a package. In some embodiments, the overwrap can be provided around a single package; in other embodiments, the overwrap is provided around a plurality of packages.
The term “bulk layer” as used herein refers to a layer used to increase the abuse-resistance, toughness, modulus, etc., of a film. In some embodiments, the bulk layer can comprise polyolefin (including but not limited to) at least one member selected from the group comprising: ethylene/alpha-olefin copolymer, ethylene/alpha-olefin copolymer plastomer, low density polyethylene, and/or linear low density polyethylene and polyethylene vinyl acetate copolymers.
The term “dome” as used herein can refer to a rounded shape, including a hemisphere or partial sphere that generally has an elliptic arc or a circular arc-shaped vertical section and horizontal section. It should be appreciated that the term “dome” is not limited to hemispherical structures and can include any of a wide variety of shapes or structures that enclose a product to be packaged (i.e., rectangular, square, etc.).
As used herein, the phrase “easy open” refers to any unit for accessing the contents of a package that obviates the need to cut and/or pierce the package with a knife, scissors, or any other sharp implement. An easy open feature can be in at least one portion of the web used to form a package and can include one or more cuts, notches, or surface-roughened areas, lines of structural weakness, or combinations thereof. Examples of such easy open features are described in U.S. Patent Application Publication Nos. 2005/0084636 to Papenfuss et al. and 2005/0254731 to Berbert et al., both of which are incorporated herein in their entireties. In some embodiments, the easy open feature can include one or more frangible or peelable layers adapted to manually separate or delaminate at least a portion of the web used to form the package, as described in U.S. Reissued Pat. No. RE37,171 to Busche et al., which is incorporated herein in its entirety. It will be appreciated that in some embodiments peelable webs can further comprise one or more reclosable peelable layers. Examples of still other alternative easy open features include reclosable interlocking fasteners attached to at least a portion of the web used to form the package. Reclosable fasteners, in general, are known and are taught, for example, in U.S. Pat. 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, all hereby incorporated by reference in their entireties.
As used herein, the term “film” includes, but is not limited to, a laminate, sheet, web, coating, and/or the like, that can be used to package a product. The film can be a rigid, semi-rigid, or flexible product, and can be adhered to a non-polymeric or non-thermoplastic substrate such as paper or metal to form a rigid, semi-rigid, or flexible product or composite.
The term “gas barrier container” refers to an oxygen-impermeable bag, envelope, or other like container that can house one or more packages. The gas barrier container includes an interior and a closure mechanism (which can include any of a wide variety of zippers, seals, fasteners, and the like known in the art). After a product is inserted into the container interior, the container can be closed or sealed for a desired amount of time. In some embodiments, before the container is sealed, a preferred gaseous environment (low oxygen or high oxygen concentrations, for example) can be inserted into the container interior.
As used herein, the term “lidding film” comprises any of a wide variety of films that can be fitted or sealed to a support member to generate an enclosed space. For example, in some embodiments, the lidding film can comprise a thermoformed film with a flange that is bonded to a support member.
As used herein, the terms “MAP” and/or “modified atmosphere package” refer to a packaging format wherein a gas is actively flushed into the headspace of a package prior to sealing. In general, the gas is modified to be different from that normally found in the atmosphere outside the MAP. The result is a package with a considerable volume of gas surrounding the viewing surface of a packaged product. An example of such a package is disclosed in, e.g., U.S. Pat. No. 5,686,126 to Noel et al., the entire disclosure of which is hereby incorporated by reference.
The term “meat” refers to any myoglobin-containing or hemoglobin-containing tissue from an animal, such as beef, pork, veal, lamb, mutton, chicken, turkey, venison, quail, and duck. The meat can be in a variety of forms including primal cuts, subprimal cuts, and/or retail cuts as well as ground, comminuted, or mixed. The meat or meat product is preferably fresh, raw, uncooked meat, but can also be frozen, hard chilled, or thawed. In some embodiments, the meat can be subjected to other irradiative, biological, chemical and/or physical treatments. The suitability of any particular such treatment can be determined without undue experimentation in view of the present disclosure.
As used herein, the term “oxygen impermeable” refers to the ability of a film or layer to serve as a barrier to one or more gases (i.e., gaseous O2). Such barrier materials can include (but are not limited to) ethylene/vinyl alcohol copolymer, polyvinyl alcohol homopolymer, homopolymer and copolymer of polyvinylidene chloride, polyalkylene carbonate, polyamide, polyethylene naphthalate, polyester, polyacrylonitrile, polyvinyl chloride (when bonded to a barrier film), homopolymer and copolymer, liquid crystal polymer, SiOx, carbon, metal, metal oxide coated films, and the like, as known to those of ordinary skill in the art. In some embodiments, the oxygen-impermeable film has an oxygen transmission rate of no more than 100 cc/m2/day/atm; in some embodiments, less than 50, 25, 10, 5, or 1 cc/m2/day/atm (tested at 1 mil thick and at 25° C. in accordance with ASTM D3985).
As used herein, the term “oxygen permeable” refers to a film packaging material that can permit the transfer of oxygen from the exterior of the film (i.e., the side of the film in contact with the outside environment) to the interior of the film (i.e., the side of the film in contact with the internal package environment). In some embodiments, “oxygen permeable” can refer to films or layers that have a gas (e.g., oxygen) transmission rate of at least about 1,000; 5,000; 10,000; 50,000; or 100,000 cc/m2/24 hrs/atm (at 73° F. in accordance with ASTM D3985). The term “permeable” can also refer to films that do not have such high gas permeability, but that are sufficiently permeable to affect a sufficiently rapid bloom for the particular product and particular end use application.
The term “oxygen sensitive” as used herein refers to the ability of a product to react with oxygen. The term includes products that oxidize in the presence of oxygen, such as whole grains, fruit, and the like. The term also includes products such as fresh red meat that bloom in the presence of oxygen.
The term “oxygen transmission rate” is measured according to ASTM D3985, a test known to those of ordinary skill in the art, and which is hereby incorporated by reference in its entirety. Further, all ASTMs referenced herein are incorporated by reference in their entireties.
As used herein, the term “package” refers to an object of manufacture that can be in the form of a web (e.g., monolayer or multilayer films, monolayer or multilayer sheets), bag, shrink bag, pouch, casing, tray, lidded tray, overwrapped tray, shrink package, vacuum skin package, flow wrap package, thermoformed package, packaging insert, or combinations thereof. It will be appreciated by those skilled in the art that such packages can include flexible, rigid, or semi-rigid materials and can be heat shrinkable or non-heat shrinkable, oriented or non-oriented. In some embodiments, a package can include a support member and a domed lidding film.
The term “permeable member” includes any of a wide variety of permeable elements known in the art, including (but not limited to) permeable polymeric films, open netting materials, barrier or non-barrier materials with one or more openings or perforations, open weave materials, fabrics, and the like. In some embodiments, the permeable member can have a gas (e.g., oxygen) transmission rate of at least about 1,000; 5,000; 10,000; 50,000; or 100,000 cc/m2/24 hrs/atm (at 73° F. in accordance with ASTM D3985).
As used herein, the term “polymer” (and specific recited polymers) refer to the product of a polymerization reaction, and is inclusive of homopolymers, copolymers, terpolymers, etc.
As used herein, the term “polymerization” can be inclusive of homopolymerizations, copolymerizations, terpolymerizations, etc., and can include all types of copolymerizations such as random, graft, block, etc. In general, the polymers in the films of the presently disclosed subject matter can be prepared in accordance with any suitable polymerization process, including slurry polymerization, gas phase polymerization, high pressure polymerization processes, and the like.
The term “removable member” as used herein refers to any of a wide variety of labels, stickers, tags, coated paper, and the like that can be removably adhered to the disclosed package (i.e., over an opening). The removable member can be attached to the package by adhesives, heat sealing, and/or other methods well known in the packaging art. As would be appreciated, the removable member can be oxygen permeable or oxygen impermeable.
As used herein, the term “ridge” refers to any of a wide variety of downward-extending (i.e., toward the packaged product) elements integral to a lidding film of the disclosed package, including (but not limited to) projections, valleys, channels, protrusions, grooves, pyramids, facets, indentations, and the like. The ridges can be linear or non-linear. In addition, the ridges can be uniformly distributed or non-uniformly distributed about the top and/or sides of the lidding film. In some embodiments, the ridges can further be distributed on the surface of the support member. The ridges can be of uniform width and depth or can vary with respect to the width and depth depending on location.
As used herein, the term “seal” refers to any bond between a first region of a film surface to a second region of a film surface. In some embodiments, a seal can be formed by heating an area to the seal initiation temperature (often with applied pressure) to weld respective film surfaces together. In some embodiments (such as modified atmosphere packages), the seal can be a hermetic seal. The heat sealing can be performed by any one or more of a wide variety of manners, such as using a heated bar, hot air, infrared radiation, radio frequency radiation, etc.
As used herein, the phrases “seal layer”, “sealing layer”, “heat seal layer”, and “sealant layer”, refer to an outer film layer, or layers, involved in the sealing of the film to itself, another film layer of the same or another film, and/or another article that is not a film. It should also be recognized that in general, up to the outer 3 mils of a film can be involved in the sealing of the film to itself or another layer. With respect to packages having only fin-type seals, as opposed to lap-type seals, the phrase “sealant layer” generally refers to the inside film layer of a package, as well as supporting layers adjacent this sealant layer often being sealed to itself, and frequently serving as a food contact layer in the packaging of foods. In general, a sealant layer sealed by heat-sealing layer comprises any thermoplastic polymer. In some embodiments, the heat-sealing layer can comprise, for example, thermoplastic polyolefin, thermoplastic polyamide, thermoplastic polyester, and thermoplastic polyvinyl chloride. In some embodiments, the heat-sealing layer can comprise thermoplastic polyolefin.
The term “support member” as used herein refers to a component of the disclosed package onto which a packaged product is directly or indirectly placed. In some embodiments, a support member can include lip or flange that provides a sealing surface for attachment of a lidding film with a cavity to thereby receive and enclose the product within the cavity.
As used herein, the term “thermoforming” comprises vacuum forming wherein a preheated softened sheet is disposed on a molding portion having the shape of a desired product, and the air present in the gap between the molding portion of the molding die and the sheet is eliminated by pulling vacuum so that the sheet conforms to the contours of the mold. The term “thermoforming” can also comprise air pressure assist molding with jointly used vacuum forming and pressure forming wherein a sheet is contacted with the molding portions by compressed air at a pressure that is not less than atmospheric pressure. Further, the term can include match mold assist forming in which a plug matching the internal shape of the mold is used to guide the deformation of the sheet. See, for example, U.S. Pat. Nos. 4,192,699; 4,576,669; 4,735,855; 5,350,622; and 5,529,833, the entire disclosures of which are incorporated by reference herein.
As used herein, the term “tie layer” refers to an internal film layer having the primary purpose of adhering two layers to one another. In some embodiments, tie layers can comprise any nonpolar polymer having a polar group grafted thereon, such that the polymer has affinity for nonpolar polymers such as polyethylene and is also capable of covalent bonding to polar polymers such as polyamide and ethylene/vinyl alcohol copolymer. In some embodiments, tie layers can comprise at least one member selected from the group including, but not limited to, modified polyolefin, modified ethylene/vinyl acetate copolymer, and/or modified homogeneous ethylene/alpha-olefin copolymer. In some embodiments, tie layers can comprise at least one member selected from the group consisting of anhydride modified grafted linear low density polyethylene, anhydride grafted low density polyethylene, anhydride grafted homogeneous ethylene/alpha-olefin copolymer, and/or anhydride grafted ethylene/vinyl acetate copolymer.
The term “vacuum skin packaging” or “VSP” as used herein refers to a process wherein a thermoformable film (i.e., capable of being formed into a desired shape upon the application of heat) is thermoformed about a product on a tray by means of heat and/or pressure. Virtually all of the air is evacuated from a predefined space around the packaging film so that when the film is attached to the tray about the product and the resultant package is subsequently exposed to atmospheric pressure, the film conforms very closely to the contour of the packaged product. Further details are described in U.S. Pat. No. RE 30,009 to Purdue et al.; U.S. Pat. No. 5,346,735 to Logan et al.; and U.S. Pat. No. 5,770,287 to Miranda et al., the disclosures of which are incorporated by reference herein.
Any compositional percentages used herein are presented on a “by weight” basis, unless designated otherwise.
Although the majority of the above definitions are substantially as understood by those of skill in the art, one or more of the above definitions can be defined hereinabove in a manner differing from the meaning as ordinarily understood by those of skill in the art, due to the particular description herein of the presently disclosed subject matter.
As set forth herein, package 5 includes support member 10, thermoformed lidding film 15, and product 20. As illustrated in the Figures, support member 10 is generally a “bottom” member (i.e., in normal usage, the package will rest on the support member). Likewise, lidding film 15 is generally a “top” member (i.e., in normal usage, the package will be positioned such that the lidding film comprises the top of the package). Nevertheless, those skilled in the art will understand after a review of the presently disclosed subject matter that package 5 can be manufactured, stored, shipped, and/or displayed in any suitable orientation.
The films used to construct support member 10 and lidding film 15 can be monolayer or multilayer. Typically, however, the films employed will have two or more layers to incorporate a variety of properties, such as sealability, gas impermeability, and toughness into a single film. Thus, in some embodiments, support member 10 and/or lidding film 15 comprise a total of from about 4 to about 20 layers; in some embodiments, from about 4 to about 12 layers; and in some embodiments, from about 5 to about 9 layers. Accordingly, the disclosed films can comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 layers. One of ordinary skill in the art would also recognize that the disclosed films can comprise more than 20 layers, such as in embodiments wherein the films comprise microlayering technology.
Support member 10 and lidding film 15 can have any total thickness desired, so long as they provide the desired properties for the particular packaging operation used, e.g., optics, modulus, seal strength, and the like. Final web thicknesses can vary, depending on process, end use application, and the like. Typical thicknesses can range from about 0.1 to 25 mils; in some embodiments, about 0.5 to 20 mils; in some embodiments, about 1 to 18 mils; in some embodiments, about 3 to 15 mils; in some embodiments, about 5 to 12 mils; and in some embodiments, about 8 to 10 mils.
Suitable materials from which support member 10 and/or lidding film 15 can be constructed include (without limitation) polyvinyl chloride, vinylidene chloride copolymer, nylon, polyethylene terephthalate, ethylene/vinyl alcohol copolymer, polyethylene terephthalate, polystyrene, high impact polystyrene, polyolefins such as high density polyethylene or polypropylene, copolymers of polypropylene, polyurethane, polyester, copolyester, polybutylene terephthalate, styrene-butadiene copolymers, polyacrylonitrile copolymers, polycarbonate, polymethylmethacrylate, polyethylene terphthalate, crystalline polyethylene terphthalate, amorphous polyethylene terephthalate, polyamides, polylactic acid, polyhydroxyalkanoates, or combinations thereof.
Thus, support member 10 and lidding film 15 can be constructed from any of a wide variety of polymeric films that can comprise one or more barrier layers, seal layers, tie layers, abuse layers, and/or bulk layers. The polymer components used to fabricate support member 10 and lidding film 15 can also comprise appropriate amounts of other additives normally included in such compositions. For example, slip agents (such as talc), antioxidants, fillers, dyes, pigments and dyes, radiation stabilizers, antistatic agents, elastomers, and the like can be added to the disclosed films. See, for example, U.S. Pat. No. 7,205,040 to Peiffer et al.; U.S. Pat. No. 7,160,378 to Eadie et al.; U.S. Pat. No. 7,160,604 to Ginossatis; U.S. Pat. No. 6,472,081 to Tsai et al.; U.S. Pat. No. 6,222,261 to Horn et al.; U.S. Pat. No. 6,221,470 to Ciocca et al.; U.S. Pat. No. 5,591,520 to Migliorini et al.; and U.S. Pat. No. 5,061,534 to Blemberg et al., the disclosures of which are hereby incorporated by reference in their entireties.
The films used to form support member 10 and lidding film 15 can be constructed using any suitable process known to those of ordinary skill in the art, including (but not limited to) coextrusion, lamination, thermoforming, extrusion coating, and combinations thereof.
In some embodiments, at least a portion of support member 10 and/or lidding film 15 can be irradiated to induce crosslinking. In the irradiation process, a film is subjected to one or more energetic radiation treatments, such as corona discharge, plasma, flame, ultraviolet, X-ray, gamma ray, beta ray, and high energy electron treatment, each of which induces cross-linking between molecules of the irradiated material. The irradiation of polymeric films is disclosed in U.S. Pat. No. 4,064,296, to Bornstein at al., which is hereby incorporated by reference in its entirety.
In some embodiments, support member 10 and/or lidding film 15 can have oxygen transmission barrier attributes, particularly when product 20 is an oxygen-sensitive food product (such as fresh red meat). In these embodiments, support member 10 and/or lidding film 15 can have a thickness and composition sufficient to provide an oxygen transmission rate of no more than about any of the following values: 1000, 500, 150, 100, 50, 45, 40, 35, 30, 25, 20, 15, 10, and 5 cc/m2-day-atm, measured at 0% relative humidity and 23° C. (ASTM D-3985).
Alternatively, support member 10 and/or lidding film 15 can be oxygen permeable in some embodiments. In these embodiments, support member 10 and/or lidding film 15 can have a permeability of greater than about 10,000; in some embodiments, greater than about 15,000; and in some embodiments, greater than about 17,000 cc/m2-day-atm at 73° C. (ASTM D-3985). In these embodiments, package 5 can optionally comprise barrier overwrap 110 that completely or partially covers the package and adheres or clings to itself or to the package, as illustrated in
In some embodiments, support member 10 and/or lidding film 15 are transparent (at least in the non-printed regions) such that product 20 is visible. The term “transparent” as used herein can refer to the ability of a material to transmit incident light with negligible scattering and little absorption, enabling objects (e.g., packaged food or print) to be seen clearly through the material under typical unaided viewing conditions (i.e., the expected use conditions of the material). The transparency of the film can be at least about any of the following values: 20%, 25%, 30%, 40%, 50%, 65%, 70%, 75%, 80%, 85%, and 95%, as measured in accordance with ASTM D1746.
a illustrates support member 10 configured as a flat, planar portion of film. The support member includes product support surface 25 for receiving and supporting the product being packaged and lip 30 to which the lidding film is sealed. In some embodiments, lip 30 comprises the outer edges of the support member (i.e., extending away from center 35). Although support member 10 can be a flat, planar portion of film, in some embodiments it can be configured as a tray and the like, as would be known in the art.
For example, as illustrated in
Support member 10 can be rigid, semi-rigid, or flexible. For example, the support member can have a 1% secant flex modulus of at least about any of the following values: 120,000; 140,000; 160,000; 180,000; 200,000; 225,000; or 250,000 pounds/square inch (in accordance with ASTM D-790).
In some embodiments, support member 10 (and/or lidding film 15) can comprise an easy open feature, such as tab 40, depicted in
In some embodiments, the bottom and/or sides of support member 10 can include one or more ridges 25, as illustrated in
Although the support members illustrated in the enclosed Figures depict a single product 20, the presently disclosed subject matter can include a support member (and/or lidding film) formed with one or more areas to house a plurality of products. For example,
Support member 10 can have any desired configuration or shape, such as circular, oval, square, rectangular, polygonal, hexagonal, etc. In some embodiments, the shape of the support member can be dictated by the shape of the lidding film and/or the packaged product.
In the case of red meat or other similar products that can include liquids of any type, the material used to construct support member 10 can be comparably dense to prevent seepage of the liquid. Absorbent trays such as those supplied by Vitembal (Avignon, France) or Linpak (Swanton, Ohio, United States of America) can be employed for this purpose. Alternatively or in addition, in some embodiments, support member 10 can comprise an absorbent pad to absorb product drip loss and to further prevent or reduce discoloration of product 20. Examples of such absorbent pads are provided in U.S. Pat. Nos. 5,320,895 and 6,278,371, the entire disclosures of which are incorporated herein by reference.
Product 20 can be positioned on support surface 25 of support member 10 using any method known in the art. Product 20 can include any of a wide variety of food products including (but not limited to) vegetables, fruit, pasta, poultry (including chicken, duck, goose, turkey, and the like), buffalo, camel, cow, dog, game (including deer, eland, antelope, and the like), game birds (such as pigeon, quail, doves, and the like), goat, hare, horse, kangaroo, lamb, marine mammals (including whales and the like), amphibians (including frogs and the like), monkey, pig, rabbit, reptiles (including turtles, snakes, alligators, and the like), and/or sheep. One of ordinary skill in the art would readily recognize that the above list is not exhaustive.
In addition, product 20 can include any of a wide variety of non-food items including (but not limited to) pharmaceuticals, photographic film, computer components, inorganic materials susceptible to oxidation, electronics, biological systems, and the like. One of ordinary skill in the art would readily recognize that the above list is not exhaustive and can include any of a variety of non-food items.
As set forth herein above, package 5 comprises lidding film 15 which can be fitted to top surface 25 of support member 10. The lidding film can be configured as a transparent thermoformed dome that has the appropriate geometry to keep product 20 from contacting large continuous areas of the lidding film. As a result, the outer surface of the packaged product is in contact with gaseous environment of the package interior. As illustrated in
Dome 65 extends upwardly from the edges of flange 65 to form enclosed cavity 70 that houses product 20. In some embodiments, the size and shape of dome 65 approximates the size and shape of product 20. As depicted in
In some embodiments, lidding film 15 can be coated or sprayed with an effective amount of an antifog agent on its interior surface (i.e., the surface facing product 20). See, for example, U.S. Pat. No. 5,451,460 and PCT International Publication No. WO/99/00250, both of which are incorporated herein in their entireties. Alternatively or in addition, in some embodiments, lidding film 15 can be constructed from an antifog film or from a material comprising one or more antifog agents. Suitable antifog agents are known in the art. See, for example, U.S. Pat. No. 7,608,312, the entire content of which is hereby incorporated by reference.
In some embodiments, lidding film 15 (and/or support member 10) comprises one or more openings 90 that allow the influx of atmospheric air into enclosed cavity 70 (i.e., into the interior of the package) at a desired time, such as at the time of retail display. In some embodiments, openings 90 are covered by a label or other removable member 95 that is removed on demand, as illustrated in
In some embodiments, package 5 optionally comprises permeable member 100 positioned between product 20 and lidding film 15 (i.e., covering the surface of the product). Permeable member 100 can be any of a wide variety of items that are permeable to oxygen, including (but not limited to) permeable films, open netting materials, and the like. Permeable member 100 prevents the transfer of product 20 to the lidding film, which would thereby reduce visibility of the packaged product. For example, when product 20 is fresh red meat, member 100 prevents the transfer of grease and/or fat onto lidding film 15. Thus, because the permeable member stays in contact with the meat surface, any grease transfer that occurs will not be visible.
Permeable member 100 can be attached or unattached to support member 10 and lidding film 15. For example, in some embodiments, product 20 can be packaged in permeable member 100 using a flow wrap-type machine with seals, partial seals, or no seals, as illustrated in
As illustrated in
As illustrated in
Once product 20 is deposited onto support member 10, lidding film 15 can be sealed to the support member to create a closed package, as illustrated in
In some embodiments, the sealing operation can occur at a food packaging plant using a heat sealing machine designed for high speed operation. Heat sealing can occur via any of a number of techniques well known in the art, such as but not limited to, thermal conductance heat sealing, impulse sealing, ultrasonic sealing, dielectric sealing, and/or combinations thereof. Other forms of sealing can be used as appropriate, including pressure sensitive adhesives, ultrasonic sealing, mechanical closures, and/or interlocking members. Lidding film 15 and support member 10 therefore form an enclosure for product 20 that protects the product from contact with the surrounding environment including dirt, dust, moisture, microbial contaminants, and optionally ambient air, especially when product 20 is a food product.
In some embodiments, construction of package 5 can also include the step of admitting a desired gas into cavity 70 immediately prior to hermetically sealing lidding film 15 to support member 10. In these embodiments, lidding film 15 and support member 10 are constructed from oxygen impermeable materials and/or are surrounded by a barrier overwrap or gas barrier container. Thus, in some embodiments, package 5 can be a modified atmosphere package (“MAP”), wherein product 20 is maintained within the interior of the package with an atmosphere that is different than ambient air. For example, fresh meat and other food products can be packaged in a low-oxygen environment (e.g., high levels of carbon dioxide and/or nitrogen) after evacuating all or most of the air from the package. Such MAP systems are well known to those of ordinary skill in the art. Examples of such MAP packaging are disclosed in U.S. Pat. No. 5,686,126 to Noel et al. and U.S. Pat. No. 5,779,050 to Kocher et al., the entire disclosures of which are hereby incorporated by reference. In some embodiments, the internal gas pressure can be atmospheric pressure, nominal atmospheric pressure, or slightly elevated gas pressure, as can be appreciated by those of ordinary skill in the art. It should be noted that the presently disclosed subject matter also comprises embodiments wherein package 5 is not a modified atmosphere package and the interior of the article comprises ambient air.
Thus, in some embodiments, the oxygen level within the interior of package 5 can be reduced to a level in the range of less than about 0.5 weight %; in some embodiments, less than about 0.1 weight %; and in some embodiments, less than about 0.05 weight %, based on the total weight of the air within the enclosed package cavity. The reduction in oxygen level can be accomplished using one or more techniques, including (but not limited to) evacuation, gas flushing, and/or oxygen scavenging. Such methods are well known to those of ordinary skill in the packaging art. In some embodiments, the modified atmosphere can include carbon monoxide, which reacts with red meat to create a bright red color with no oxygen present. Package 5 is then sealed to provide an airtight, sealed container containing an internal low-oxygen atmosphere. The modified package can then be stored in a refrigeration unit for several weeks prior to being offered for sale at a retail establishment.
Another type of MAP employs a high-oxygen internal environment for fresh red meat or poultry. In these embodiments, ambient air is evacuated from the interior of package 5 and replaced with a high-oxygen environment (i.e., about 80% oxygen and about 20% carbon dioxide). Thus, for example, in some embodiments the interior of the modified atmosphere package can include at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% oxygen. In some embodiments, the package further comprises at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% carbon dioxide. The high-oxygen environment preserves the meat and maintains the desirable bright red color for a period of about 14 days.
As discussed herein above, package 5 can be shipped to a retail distributor in the embodiment depicted in
In embodiments wherein package 5 is packaged within barrier overwrap 110 or gas barrier container 115, a user simply removes the package from the overwrap or gas barrier container. In these embodiments, support member 10 and/or lidding film 15 are constructed from permeable materials, such that ambient air is allowed to flow into the package interior to contact product 20.
Alternatively or in addition, a physical opening can be created in the package, such as by the retailer breaching the integrity of the support member or lidding film (e.g. a knife cut, punched hole, etc.), though it is generally preferably that the package remains sealed. Further, package 5 can in some embodiments comprise openable and closeable valve members to admit ambient air into the package interior on demand. Such valve members are well known in the packaging art.
The presently disclosed package allows the viewing surface of a product to be in constant contact with a desired gas concentration. In case of fresh red meat, for example, the package displays a product that exhibits a bright red color as desired for commercial sale.
Further, the disclosed package solves the problem of how to prevent relatively large areas of the packaged product from being in direct contact with a barrier film. In the case of fresh red meat, for example, contact with a barrier film results in a discolored area on the meat due to inadequate contact with the interior package gas. By minimizing contact between the lidding film and large areas of the meat, the red color of the meat is maintained, which has proved to be desirable to consumers. In addition, the areas of grease transfer from the product to the lidding film are minimized.
The disclosed package also enables a large percentage of the packaged product to be visible, compared to prior art packages (such as fresh red meat packages wrapped in a barrier overwrap, for example). The high visibility results from the high profile and favorable optical properties provided by the convex lidding film.
Continuing, the disclosed packages take up less volume during shipping and storage compared to prior art packages. Accordingly, retailers are able to ship more packages to the end use location, thereby reducing shipping and storage costs per unit.
In addition, the disclosed packages can be produced at a lower cost compared to similar packages known and used in the art.
Further, the disclosed packages are simple in design compared to some prior art systems. Particularly, high and low oxygen gas barrier containers known in the art are shipped in a separately maintained gas environment and optionally oxygen absorbers, which add an additional processing step.
Although several advantages of the disclosed system are set forth in detail herein, the list is by no means limiting. Particularly, one of ordinary skill in the art would recognize that there can be several advantages to the disclosed system that are not included herein.
The following Examples provide illustrative embodiments. In light of the present disclosure and the general level of skill in the art, those of ordinary skill in the art will appreciate that the following Examples are intended to be exemplary only and that numerous changes, modifications, and alterations can be employed without departing from the scope of the presently disclosed subject matter.
The support member of Package 1 was a thermoformed film (VC716WB, provided by Cryovac, Inc., Duncan, S.C., United States of America) with the approximate dimensions 5 inches×7 inches×18 inches (18 mils thick), with a recessed portion sized to receive two 0.5 pound units of fresh red meat. The lidding film was a 12 mil PVC film laminated to a coextruded barrier film containing PE sealant layers, an EVOH barrier layer, and PE outer layer (available from Pack-All Inc., Melrose Park, Ill., United States of America). The surface of the lidding film included a blend of antifog materials that bloomed to the film surface after extrusion, which reduced the creation of condensation on the inner surface of the formed lidding film. During the packaging step, 3 or 4 inwardly-facing ridges of a depth of about 0.25 inches were included on the top and sides of the lidding film.
The meat product was then placed on the thermoformed part of the support member and a vacuum source was applied to remove most of the atmospheric oxygen from the package. The package was then back flushed with a mixture of about 25 weight % carbon dioxide and 75 weight % nitrogen gas, and the lidding film was sealed around the perimeter of the support member with a Multivac packaging machine (available from Multivac, Inc., Kansas City, Mo., United States of America) using standard thermal transfer heat sealing techniques.
Package 2 was constructed using the same method as Package 1, except that the package interior was flushed with a gas mixture of 80 weight % oxygen and 20 weight % carbon dioxide prior to sealing the lidding film to the support member.
Package 3 was constructed using the same method as in Package 1, except that the package interior was flushed with a tri-gas mixture of 0.7 weight % carbon monoxide gas, 20% carbon dioxide, and 79.3 weight % nitrogen gas prior to sealing the lidding film to the support member.
Package 4 was produced using the same method as Package 3, except that the meat was pre-treated by exposing the meat to carbon dioxide (0.7 weight %) and the meat surface was observed to be bright red in color.
Package 5 was produced using the method for Package 1, with the additional step of wrapping the entire surface of the meat with a piece of permeable polyolefin film (Mirabella® DL150, provided by Cryovac, Inc., Duncan, S.C., United States of America) prior to placing it on the support member.
Package 6 was produced using the method for Package 3, with the additional step of wrapping the meat with a piece of permeable polyolefin film (Mirabella® DL150) prior to placing it on the support member.
Package 7 was produced using the method for Package 4, with the additional step of wrapping the meat with a piece of permeable polyolefin film (Mirabella® DL150) prior to placing it on the support member.
Packages 1-4 were incubated for 4-8 days at about 36° F. Blooming of Packages 1, 3, and 4 was initiated by manually piercing a ⅛ inch diameter hole into the lidding film. The blooming of the packages was then observed as follows:
Package 1 maintained the meat in a reduced state (purple color) until the package was pierced. Thereafter, the meat bloomed to a red color.
Package 2 was not pierced, but maintained a red color due to the high oxygen atmosphere within the package interior.
Package 3 maintained a bright red color over the course of the refrigeration. Upon piercing, the package maintained the bright red color for about 2-3 days until the meat turned a brown color.
Package 4 maintained a bright red color over the course of the refrigeration. Upon piercing, the package maintained the bright red color for about 2-3 days until the meat turned a brown color.
Packages 5-7 were manually inverted and shaken for about 10 seconds to allow the meat to contact the transparent lidding film. The packages were then inspected for grease transfer to the lidding film. It was noted that no grease transfer was observed with Packages 5-7.
A Cryovac Mirabella® package (available from Sealed Air Corporation, Duncan, S.C., United States of America) consisting of a flanged tray and 2-part lidding film (an inner permeable film and an outer gas barrier film) was provided. About 1 lb. of fresh sliced round steak was loaded onto the tray and positioned such that the meat did not project above the plane of the tray flange. The lidding film was hermetically sealed to the tray flange under standard conditions (i.e., at a sealing temperature of about 135° C. and a sealing time of about 0.5 seconds). A modified atmosphere gas mixture of 80 weight % oxygen and 20 weight % carbon dioxide was gas flushed into the package cavity and between the two lidding films just prior to sealing the lidding film to the tray flange. It was observed that the meat was not in contact with the lidding film in the final package configuration. The package was then refrigerated at about 4° C. for 5 days.
After the refrigeration, it was observed that the meat surface of Comparative Package 1 exhibited a bright red color.
A Cryovac Mirabella® package as in Example 4 was provided. About 1.5 lbs. of fresh sliced round steak was loaded onto the tray and positioned such that the meat projected about 1.5 inches above the plane of the tray flange. The lidding film was then hermetically sealed to the tray flange under standard conditions with the inner permeable film in direct contact with the protruding portion of the meat. As a result, the lidding film was tented in appearance, causing the inner and outer films to be pressed into contact. A modified atmosphere gas mixture of 80 weight % oxygen and 20 weight % carbon dioxide was gas flushed into the package cavity and between the two lidding film components just prior to sealing the lidding film to the tray flange. The package was then refrigerated at about 4° C. for 5 days.
After the refrigeration, it was observed that the meat surface of Comparative Package 2 exhibited a brown color. It is believed that the meat received insufficient oxygen resulting from the loss of atmospheric separation between the two layers of the lidding film.
A Cryovac Mirabella® package as in Example 4 was provided. About 1 lb. of fresh sliced round steak was loaded onto the tray and positioned such that the meat projected about 0.125 inches above the plane of the tray flange. The lidding film was then hermetically sealed to the tray flange under standard conditions such that the inner permeable film was in direct contact with the protruding portion of the meat. A modified atmosphere gas mixture of 80 weight % oxygen and 20 weight % carbon dioxide was gas flushed into the package cavity and between the two lidding film components just prior to sealing the lidding film to the tray flange. The package was refrigerated at about 4° C. for 5 days.
After the incubation, it was observed that the meat surface of Comparative Package 3 exhibited bright red color. It is believed that the volume of modified gas trapped between the two lidding films was able to provide sufficient pressure to retain a separation.
