CA2178254A1 - Dual tray, dual web package having improved gaseous exchange - Google Patents
Dual tray, dual web package having improved gaseous exchangeInfo
- Publication number
- CA2178254A1 CA2178254A1 CA 2178254 CA2178254A CA2178254A1 CA 2178254 A1 CA2178254 A1 CA 2178254A1 CA 2178254 CA2178254 CA 2178254 CA 2178254 A CA2178254 A CA 2178254A CA 2178254 A1 CA2178254 A1 CA 2178254A1
- Authority
- CA
- Canada
- Prior art keywords
- support member
- flange
- sealed
- set forth
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000009977 dual effect Effects 0.000 title claims description 14
- 239000007789 gas Substances 0.000 claims abstract description 31
- 230000002093 peripheral effect Effects 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 34
- 239000001301 oxygen Substances 0.000 abstract description 34
- 229910052760 oxygen Inorganic materials 0.000 abstract description 34
- 235000020989 red meat Nutrition 0.000 abstract description 10
- 238000004806 packaging method and process Methods 0.000 abstract description 5
- 235000013372 meat Nutrition 0.000 description 21
- 230000004888 barrier function Effects 0.000 description 14
- 239000010410 layer Substances 0.000 description 11
- 235000013622 meat product Nutrition 0.000 description 9
- 238000012545 processing Methods 0.000 description 8
- 238000007789 sealing Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 239000005038 ethylene vinyl acetate Substances 0.000 description 5
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 5
- 239000000565 sealant Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- 239000004677 Nylon Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 238000011109 contamination Methods 0.000 description 3
- -1 for example Polymers 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 229920000092 linear low density polyethylene Polymers 0.000 description 3
- 239000004707 linear low-density polyethylene Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229920001778 nylon Polymers 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 239000004711 α-olefin Substances 0.000 description 3
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000005033 polyvinylidene chloride Substances 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- WJGVWFOXHWYCHL-UHFFFAOYSA-N 1,1-dichloroethene;methyl prop-2-enoate Chemical compound ClC(Cl)=C.COC(=O)C=C WJGVWFOXHWYCHL-UHFFFAOYSA-N 0.000 description 1
- 238000003855 Adhesive Lamination Methods 0.000 description 1
- 229920000089 Cyclic olefin copolymer Polymers 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229920000219 Ethylene vinyl alcohol Polymers 0.000 description 1
- 241000257303 Hymenoptera Species 0.000 description 1
- 229920010126 Linear Low Density Polyethylene (LLDPE) Polymers 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- XDXHAEQXIBQUEZ-UHFFFAOYSA-N Ropinirole hydrochloride Chemical compound Cl.CCCN(CCC)CCC1=CC=CC2=C1CC(=O)N2 XDXHAEQXIBQUEZ-UHFFFAOYSA-N 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 description 1
- DHZSIQDUYCWNSB-UHFFFAOYSA-N chloroethene;1,1-dichloroethene Chemical compound ClC=C.ClC(Cl)=C DHZSIQDUYCWNSB-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229920006228 ethylene acrylate copolymer Polymers 0.000 description 1
- 229920006242 ethylene acrylic acid copolymer Polymers 0.000 description 1
- 229920001038 ethylene copolymer Polymers 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000012968 metallocene catalyst Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 238000010943 off-gassing Methods 0.000 description 1
- 238000012858 packaging process Methods 0.000 description 1
- 239000011087 paperboard Substances 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 235000013613 poultry product Nutrition 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
Landscapes
- Packages (AREA)
- Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
Abstract
A package which allows for butchering and packaging of fresh red meat at a centralized facility is provided which includes an inner tray receiving the product, an outer tray receiving the inner tray, a gas permeable film sealed to the inner tray and the outer tray enclosing the product, a gas impermeable film sealed to the outer tray enclosing the permeable film and perforations defined within the inner tray and open channels defined by the permeable film which allow for rapid introduction of oxygen to the packaged product upon removal of the impermeable film.
Description
.
BACKGROUND OF ~F INV~NTION
The present invention relates generally to packages for fresh red meat. Particularly, this invention is directed to the 5 packaging of f ood products such that the packaged product may be maintained in one condition under certain circumstances and then converted to another condition. Specifically, packages in accordance with the present invention provide for distribution of a packaged product in a low oxygen environment and for introduction 10 of oxygen to the product surface at a supermarket or other retail outlet. Such introduction of oxygen is achieved either by permeation of oxygen through a film in contact with the product ~urface or through an exchange of atmospheric oxygen with a low oxygen gaseous atmosphere contained around the product.
While a wide variety of food products can be packaged in accordance with the teachings of this invention, it is particularly advantageous in connection with the packaging of fresh red meat such that the meat may be transported in a low oxygen atmosphere, that is, preferably 0.596 2 or less, most preferably 0.0596 l or 20 less, and then caused to bloom when it reaches a supermarket by exposure to oxygen.
Historically, large sub-primal cuts of meat have been butchered and packaged in each supermarket. This, however, can be inefficient and result in certain undesirable additional costs.
25 For example, all cuts from a large sub-primal must be sold at once.
Instead it would be preferable to permit the meat to be butchered 2 ~ 78254 and packaged at a central facility which benefits from economies of scale and thereafter shipped to individual supermarkets such as is done, for example, with many poultry products.
In the past, the goal of central fresh red meat pror~ ;ng has 5 not been achievable because most consumers prefer to buy meat which is reddened in color as a result of ~oDuLe to oxygen. However, the meat maintains its reddened color for approximately one to three days and, thereafter, turns a brown color which is undesirable to most consumers.
Therefore, if the meat was butchered and packaged in a gas permeable (hereinafter "permeable") film, as is typical at retail, at a central location and then shipped to another location for eventual sale, in all ~ikf~l ih~od~ by the time the package reached the retail outlet the meat would have undergone the transformation 15 to the brown color and would be effectively l~n~ hle. Conversely, if the meat was butchered and packaged at a central location in a gas-impermeable (hereinafter "impermeable") film, either under vacuum or with vacuum and a low oxygen gas f lush, and then shipped to another location for eventual sale, the meat would reach the 20 retail outlet having a purple color which is typical of meat prior to exposure to oxygen. Heretofore, marketing efforts to teach the consumer about the harmlessness of the purple color have proved to be difficult. And, if the gas imp~L --hl~ film was a ~ t of a conventional package having a tray which is overwrapped or lidded 25 with a film and which contains a low oxygen atmosphere, the impermeable f ilm would have to be removed and replaced with a -2 t 78254 .
permeable film in order to allow for bloom of the meat to a bright red color prior to display for the consumer, negating to a large extent the benefits of a central processing facility.
A variety of packages have been developed in an effort to 5 provide a means for transporting meat in a low oxygen environment and for quickly and easily introducing oxygen to the meat at the retail outlet immediately prior to display to the consumer.
One approach to solving this problem has involved the development of peelable f ilms . That is, f ilms have been developed 10 which readily delaminate into p~ -hl e and impermeable portions.
Such a film is sealed to a support member, such as a tray, which contains the meat product, thereby forming a gas imperme~ble package for distribution. At the retail outlet, the gas impermeable portions are peeled from the film leaving a permeable 15 film sealed to the tray and, therefore, a gas permeable package which allows the meat to bloom to bright red because of the exchange with atmospheric oxygen.
The peelable film may extend over the contained product and be sealed to the periphery of the tray as a lid or it may be heated 2~ and draped over the product under vacuum to form to a vacuum skin package. However, for both types of packages the principal drawback is the relatively low gas trAnC~ ion rate of the permeable film portion after removal of the; - --hle portion.
That is, although the permeable portion of the peelable film has a 25 much higher gas tr~n~ ion rate than that of the entire f ilm prior to ~ela~i~atio~, 5,000 to 25,000 cc/2'/2~ hrs./~t2. I~t 73'F
as compared to 0 to 50 cc/m2/24 hrs./atm. at 73F prior to delamination, it is still too low to effect bloom of the packaged meat in a low oxygen gaseous atmosphere in a short period of time, except in areas of intimate permeable film to meat contact.
Most of the other approaches to achieving the goal of central fresh red meat processing have involved the development of a variety of dual web packages of the type having a permeable film covering the meat product and an; --hle film, which is removed at the retail outlet, covering the permeable film wherein the permeable film and the impermeable film are separate, discreet films .
Examples of these types of packages include dual overwrap packages wherein a permeable film is wrapped around the meat and its support member and an impermeable film is wrapped about the permeable film; dual lid packages which include a permeable lid and an impermeable lid sealed to the periphery of the support member;
and packages with a head space which allows for the introduction of a treating gas, typically nitrogen, carbon dioxide or some mixture of the two, between a permeable film adjacent to the meat product and an impermeable upper web. But, as is the case with the peelable films discussed above, each of these dual web packages are limited in their effectiveness by the p~ -h;~ity of the p~ -hle film. Typical gas transmission rates for commercially viable gas permeable films are 5,000 to 25,000 cc/m'/24 hrs./atm. at 73F which is too low to effect rapid red meat bloom by exchange of the low oxygen gases out and the atmospheric oxygen in.
.
A further package developed to allow for central fresh red meat processing includes a gas impermeable upper lid with a valve defined in the lid. The package may include a treating gas between the packaged meat and the upper lid during distribution which is 5 withdrawn through the valve and replaced with an oxygen-rich gas.
Although a rapid bloom is possible with this system, it has the disadvantages of requiring trained operators at the retail outlet and relatively expensive equipment to exchange each package thus negating the cost savings of a central processing facility. The 10 presence of the valve has the further disadvantage of creating a package appearance which is different from that which CUI~ rS are accustomed to seeing for meat packaging. Further, a gas space between the meat product and the impermeable film is required to maintain a bloomed color which yields an underf illed package 15 appearance.
Yet another package developed to allow for central fresh red meat processing provides for an excellent exchange of gases and rapid introduction of oxygen in which an upper imperme2ble web covers a lower permeable web which includes unsealed areas in the 20 seal of the permeable web to the tray. However, the intermittent sealed and nonsealed areas are formed by an altered sealing head which comprises a series of sealing "fingers" rather than a conventional, continuous sealing surface.
Thus, it is an ob ject of the present invention to provide a 25 package which allows for central processing of fresh red meat with mini~l processing requi~ed at re~ail.
2 1 7~254 It is yet another object of the present invention to provide a package which is similar in appearance to that which cu~ rS
are accustomed to seeing for meat packaging.
It is a further object of the present invention to provide a 5 package which allows for rapid bloom of fresh red meat.
It is yet another object of the present invention to provide a package which may be assembled, filled and sealed at a central processing facility on conventional equipment.
SUM~A~Y OF T~ INVF~TION
These as well as other objects are achieved by providing a package for a product which includes a product, an inner support member having a cavity for receiving the product and a peripheral 15 flange, an outer support member having a cavity for receiving the inner support member and a peripheral flange, a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product, open 20 ~h~nnf~ defined by the inner support member providing for a free f low of gases between the cavity of the inner support member and the cavity of the outer support member, an i ~nr~ hle f ilm enclosing the permeable film, and open r-h;lnn~ defined by the permeable film, such that the removal of the i~r ~~hle film 25 allows for a free flow of gases between the external environment and the packaged product via the open ~h~nn~ def ined by the permeable film and the channels defined by the inner support member .
Such objects are also achieved by providing a package for a product which includes a product, an inner support member having a 5 cavity formed by a base and side walls for receiving product and a peripheral flange, the side walls of the inner support member having a plurality of perforations defined therein, an outer support member having a cavity for receiving the inner support member and a peripheral flange, a permeable film sealed to the 10 upper flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product, an impermeable film enclosing the permeable film, and open ~-h~nn~l c defined by the permeable film, such that the removal of the impermeable film 15 allows for a free flow of gases between the external environment and the packaged product via the open ~-hAnn~lR and the perforations def ined within the inner support member .
RRTRl;' DRS-'RTP'I'ION OF THE nRAWTNGS
A detailed description of preferred embodiments of the invention follows, with reference to the accompanying drawings, wherein:
Fig. 1 is a perspective view of a package in accordance with 25 the present invention;
Fig. 2 is a cross-section of the package of Fig. 1;
Fig. 3 is a cross-section of another ~mho-lir-mt of the packaqe of the present invention:
Fig. 4 is a cross-section of yet another omho~lir L of the package of the present invention;
Fig. 5 is a partial cross-section of a still further t of the package of the present invention;
Fig. 6 is a partial cross-section of another ~ t of the package of the present invention:
Fig. 7 is a partial cross-section of yet another ` ';- t of the package of the present invention:
Fig. 8 is an enlarged sectional perspective view of the package of Fig. 7 during removal of the imr~ -~hle film Fig. 9 is a partial cross-section of a still further embodiment of the package of the present invention; and Fig. 10 is a partial cross-section of another embodiment of the package of the present invention.
DETATrrn DES~RTPTION OF TT~r pRr~rRRFn EMr~oDIMr~NTs The present invention is directed to a tray-type package for meat and other perishable goods which includes an outer support member or tray, an inner support memher or tray nested in the outer tray, a permeable film sealed to both the inner tray and the outer tray and an impermeable film enclosing the p~ --hlf~ film. The package most preferably includes a low oxygen gaseous atmosphere, such as a nitrogen/carbon dioxide mix. Perforations defined within the permeable f ilm between its seal to the inner tray and its seal to the outer tray and perforations defined within the tray walls of the inner tray act together to form open rh~nnPl ~ for the rapid release of the low oxygen atmosphere and introduction of oxygen to s the packaged product upon removal of the impermeable film at retail while essentially precluding contamination of the packaged product.
Looking specifically to the figures of the drawing, Figure 1 shows a package 10 in accordance with the present invention. An outer support member or tray 12 includes a base 14 and side walls 16 which define a cavity 18. A flange 20 extends outwardly from the upper periphery of the side walls and includes an outer flange portion 22 and an inner flange portion 24 separated by a depression 26. Inner support member or tray 28 includes a base 30 and side walls 32 defining a cavity 34 for receiving a product 36. An upper 15 flange 38 extends outwardly about the upper periphery of the side walls .
As is better seen in the cross-sectional view of Figure 2, inner tray 28 is received by and contained within cavity 18 of outer tray 12. Preferably, ridges 40 are formed in the base of the 20 inner tray, such that a major portion of the bott~ ~ surface of inner tray base 30 is maintained at least slightly above the uppermost surface of outer tray base 14.
As may also be seen from Figure 2, the inner tray is nP~-P~s~rily smaller than the outer tray. It is also preferred that 25 the inner tray has a height from the bottommost surface of its base ~o the ~ sur~ace of its f~ange which is less than that of . 2178254 the outer tray and which, when the inner tray is nested in the outer tray, allows for the respective flanges of the two trays to be substantially coplanar. Thus, permeable film 42 may be sealed to both flanges while maintaining a substantially flat configuration. However, it is also within the scope of the present invention to provide the flange of the inner tray either below or above the level of the outer tray f lange .
Regardless of the relative levels of the two flanges, permeable film 42 is sealed to the flange 38 of the inner tray forming an inner seal 44 and to the inner portion 24 of flange 20 of the outer tray forming an outer seal 46. T ,- --hle film 48 is sealed to the outer portion 22 of outer tray flange 20 only.
Perforations 50 are defined within permeable film 42 between inner seal 44 and outer seal 46. Perforations 52 are defined within side walls 32 and, less preferably, base 30 of inner tray 28. Thus, upon removal of the ;r~r- --hle film, open ~-hAnnPlc are defined between the external c~ Are and the packaged product allowing for a rapid introduction of oxygen and a correspon~l; nAjl y rapid blooming of a packaged meat product.
The present inventive package has the unusual advantage of allowing for a free flow of gases to and from a packaged product while essentially precluding contamination of the product. After removal of the impermeable film, any contaminants entering the package through perforations 50 deîined within the p~ --hle film are trapped at the lower portion of the package at base 14 or between base 14 and base 30 and away from the packaged product.
2 t 78254 Thus, it is preferred that ridges 40 are defined within base 30 to provide ample space for receipt of any contaminates and it is preferred that perforations are not included in base 30 of the inner tray.
llowever, for applications where a space is not desired between the two bases, ridges may be omitted as is shown in Figure 3. For such embodiment package 60 includes outer tray 62 having a base 64.
Inner tray 66 includes base 68 which rests directly on the upper surface of outer tray base 64. Similarly, where contamination is unlikely or of less concern, perforations may be defined in an inner tray base which includes ridges to allow for a f low of gases to and from the bottom side of the packaged product. Such a construction may also be preferred as a means to allow any emitted blood or other liquid, known as purge, to be drained away from the lS meat product for a neater appearance when a ~ r is viewing the package through the permeable f ilm as is shown in Figure 4 .
Package 70 includes outer tray 72 having a base 74. Inner tray 76 includes a base 78 with ridges 80 and perforations 81 defined therein. A soaker pad 82 is preferably included between the inner tray base 78 and outer tray base 74.
A further alternative P~hoA;r--~t is the provision of a single flange rather than a dual flange for the outer tray. Such may be employed when a precise means is available for sealing the permeable film to an inner portion of the single flange and for subsequently sealing the i - -hl e f ilm to an outer portion of ingle il6gge ~ di~closed i= ~pe=di~ U.S. Seri-il No.
.
That is, the primary reason a dual flange is preferred for use on the outer tray of the present invention is that it facilities the automated sealing of two separate webs to the flange. In the embodiment of Figure 6 package 90 includes outer tray 92 with flange 94. Inner tray 96 includes flange 98.
Permeable film 100 is sealed to flange 98 and to the inner periphery of flange 94. Impermeable film 102 is sealed to the outer periphery of flange 94 outboard of the seal between the permeable film and the flange.
A second circumstance under which a single flange may be employed on the outer tray of the present inventive package is when an adequate, peelable seal may be made between the i ~J~L --hle film and the permeable film. Rather than sealing the illl~ L - hle film directly to the outer tray, it is possible, with the proper selection of film c~ Ants, to form a seal directly to the permeable film which may be peeled away without disturbing the seal between the permeable film and the outer tray flange. Such a tray is set forth in Figure 5. P~ckage 110 ;nAl~ e-A outer tray 112 having flange 114. Inner tray 116 includes flange 118. Permeable film 120 is sealed to flange 118 and flange 114. T --hle film 122 is sealed to permeable film 120 and may be peeled away without disrupting the seal between permeable film 120 and flange 114.
As a further variation, a single film which is capable of delaminating into a po -hle web and an imr~ --hle web may be partially perforated therethrough, with complete perforations being formed through the permeable port on, at the appropriate location, ~t 78254 .
as is disclosed in copending U.S. Serial No. . Such a film may be sealed at the permeable 3ide thereof to the two f langes .
When the impermeable portion is ~ ;n~ted and removed, perforations formed in the permeable web between the seals with the inner tray and outer tray flanges form open channels which act with perforations in the inner tray to allow for a rapid gas exchange.
Yet a further alternative embodiment of the present invention employs a tray disclosed in copending U.S. Serial No. , which is a dual f lange tray having grooves def ined in the inner portion of the dual flange. Looking specifically to Figure 7, the outer tray 161 of package 160 has a cavity 162 and an upper flange 164 which includes inner flange portion 166 and outer flange portion 168 separated by depression 170. As above, depression 170 allows for trimming of any film sealed to the inner flange portion 166 and provides a clear delineation between the sealing area for an inner permeable film and an outer impermeable film.
In the present omho~;- t, inner flange portion 166 includes grooves 172 defined therein and spaced about the perimeter of the flange. As can be seen from the drawing of Figure 8, a top ; _ --hle film 174 is sealed to the support member at outer flange portion 168. Preferably, a peelable seal is formed between the ;~r~ --hle film 174 and outer flange portion 168 such that the outer i~.~eL --hle film may be readily removed from the package at retail .
Figure 8 is an enlarged sectional view of the upper flange 164 of package 160 upon removal of impermeable film 174. Permeable film 176 is sealed to the support member at inner flange portion 166. However, ~rooves 172 defined in inner flange portion 166 provide for open channels between the tray cavity 162 and depression 170. When impermeable film 174 is sealed to outer flange portion 168, depression 170 is enclosed, as is shown in Figure 7. However, upon removal of film 174, depression 170 and grooves 172 def ine open ~-hAnn~l c into tray cavity 162 . Inner tray 180 includes side walls 182 having perforations 184 defined there.
Thus, removal of film 174 allows for a rapid release of the low oxygen atmosphere and introduction of oxygen to the packaged product via the open channels def ined by grooves 172 and perforations 184. Therefore, by the present embodiment it is not necessary to perforate the permeable film during the packaging process .
As yet a further alternative embodiment the inner tray may include grooves defined in its single flange such that perforations within the tray side walls are not needed. Such embodiment is illustrated in the cross-sectional view of Figure 9 in which package 200 includes outer tray 202 and inner tray 204. Grooves 206 defined in the flange 208 of inner tray 204 eliminate the need for perforations in side walls 210. In combination with perforations 212 defined in permeable film 214, such grooves allow for a release of any contained low oxygen gaseous c~ re and for a rapid introduction of oxygen to the packaged meat product 216, as is shown, upon removal of an upper i -hle film.
When used in conjunction with the dual flanged tray having ~ 2 1 7825~
grooves in the inner flange portion, discussed above, perforations in both the tray side walls and the film, between the two trays, are 2voided as is shown in the cross-sectional view of Figure 10.
For that ~ t, package 220 includes outer tray 222 with dual flange 224 having an outer portion 226, an inner portion 228 and depression 230 therebetween. Inner flange portion 228 includes grooves 232. Inner tray 234 has a single flange 236 with grooves 238 defined therein. Upon removal of an upper impermeable film grooves 232 and grooves 238 provide an open channel between the external atmosphere and the packaged meat product 240, as is shown.
Regardless of the package configuration employed, it is preferred that the inner tray of the present inventive package is a solid rigid polymer such as, for example, polyester, polystyrene, high density polyethylene, or polyvinyl chloride, laminated with a sealant layer. Foamed polymers are less preferred because of possible outg~c~;n~ of oxygen and other residual gases into the low oxygen c~ re of the package. However, foamed trays which include barrier sealant films laminated to both surfaces thereof are also within the scope of the present invention.
The outer tray must act as a barrier but may be a rigid solid polymer, a barrier sealant coated polymer, a barrier sealant coated foamed polymer, or a barrier sealant coated pulp or paperboard tray. If foamed, the outer tray only requires a barrier film on the inner surface in order to prevent outgassing of residual gases into the package.
The permeable f ilm or web of the present invention is an 2 t 78254 oxygen permeable or non-barrier film or skin which may be a formable or stretchable material. Typical polymeric materials for the present permeable film may include any material which may be securely sealed and bonded to the support member, such as 5 polyethylene or any of a variety of ethylene copolymers including, for example, ethylene vinyl acetate, ethylene acrylate copolymers, ethylene acrylic acid copolymers including metal neutralized salts thereof, and ethylene alpha-olefin copolymers. Such ethylene alpha-olef ins may be heterogeneous or ht j "~US in nature . That 10 is, ethylene alpha-olefins which have been formed by conventional Zeigler-Natta catalysis and are heterogeneous in nature, such as linear low density polyethylene (LLDPE), are within the scope of the present invention as well as such copolymers which are formed by single site catalysis, such as any of a variety of forms of 15 metallocene catalyst technology, and are homogeneous in nature are also within the scope of the present invention. A preferred permeable film for use in accordance with the present invention is a symmetrical, five layer oriented film having the ~ u~;LuLe:
EVA / LLDPE / EVA / LLDPE / EVA
20 although a wide variety of permeable films may be employed.
The impermeable film or web of the present invention may be any suitable barrier layer, film or laminate which is substantially impermeable to gas such as oxygen so that a fresh meat product contained in a vacuum or other low oxygen ai -- re pocct~qc-t~c an 25 t~nh lnt-t~c~ shelf life over a package without the barrier layer.
Suitable polymeric materials having gas barrier properties for use ~ 21 78254 in the present invention include ethylene vinyl alcohol copolymers, vinylidene chloride copolymers (PVDC) such as vinylidene chloride vinyl chloride or vinylidene chloride methyl acrylate. Laminates of a sealable film and a barrier structure which includes a barrier 5 layer and a tough, non-forming material such as a biaxially oriented nylon or biaxially oriented polyester are especially preferred for use as the impermeable lidding of the present inventive packages. A preferred impermeable web has the structure:
biax nylon / PVDC // EVA / LLDPE / seal lO wherein the double slashes (//) indicate adhesive lamination of the two webs, although a variety of laminates and multilayer films may be employed as the impermeable web of the present invention.
Generally, the films or webs which may be employed in accordance with the present invention may be monolayer or 15 multilayer. Nultilayer films may be employed when all of the properties required of the f ilm cannot be achieved by a single polymeric component or a blend of polymers in a single layer. For example, an impermeable film to be sealed to a tray in all l;kf-l;h~lod will comprise a multilayer film because several 20 properties are needed including peelable sealability, oxygen barrier and impact properties, and outer abuse properties. Thus, the film employed will most likely contain three layers at a minimum: a seal layer, a barrier layer and an outer abuse layer.
Further internal layers such as adhesive layers and bulk layers may 25 also be included. Laminates of sealable films and nonforming materials such as biaxially oriented polyester or biaxially oriented nylon are also within the scope of the present invention and are widaly recognized as superior lidstocks for tray-type packages .
The foregoing description of preferred ' ~ ts of the 5 invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above t~ch; ngs or may be acquired from practice of the invention. The ~ ;r--~ts were 1~ chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various ~ ; r S and with various modif ications as are suited to the particular use contemplated. It is intended that the scope of the invention be 15 def ined by the claims ~rp-~n~led hereto, and their e~uivalents .
BACKGROUND OF ~F INV~NTION
The present invention relates generally to packages for fresh red meat. Particularly, this invention is directed to the 5 packaging of f ood products such that the packaged product may be maintained in one condition under certain circumstances and then converted to another condition. Specifically, packages in accordance with the present invention provide for distribution of a packaged product in a low oxygen environment and for introduction 10 of oxygen to the product surface at a supermarket or other retail outlet. Such introduction of oxygen is achieved either by permeation of oxygen through a film in contact with the product ~urface or through an exchange of atmospheric oxygen with a low oxygen gaseous atmosphere contained around the product.
While a wide variety of food products can be packaged in accordance with the teachings of this invention, it is particularly advantageous in connection with the packaging of fresh red meat such that the meat may be transported in a low oxygen atmosphere, that is, preferably 0.596 2 or less, most preferably 0.0596 l or 20 less, and then caused to bloom when it reaches a supermarket by exposure to oxygen.
Historically, large sub-primal cuts of meat have been butchered and packaged in each supermarket. This, however, can be inefficient and result in certain undesirable additional costs.
25 For example, all cuts from a large sub-primal must be sold at once.
Instead it would be preferable to permit the meat to be butchered 2 ~ 78254 and packaged at a central facility which benefits from economies of scale and thereafter shipped to individual supermarkets such as is done, for example, with many poultry products.
In the past, the goal of central fresh red meat pror~ ;ng has 5 not been achievable because most consumers prefer to buy meat which is reddened in color as a result of ~oDuLe to oxygen. However, the meat maintains its reddened color for approximately one to three days and, thereafter, turns a brown color which is undesirable to most consumers.
Therefore, if the meat was butchered and packaged in a gas permeable (hereinafter "permeable") film, as is typical at retail, at a central location and then shipped to another location for eventual sale, in all ~ikf~l ih~od~ by the time the package reached the retail outlet the meat would have undergone the transformation 15 to the brown color and would be effectively l~n~ hle. Conversely, if the meat was butchered and packaged at a central location in a gas-impermeable (hereinafter "impermeable") film, either under vacuum or with vacuum and a low oxygen gas f lush, and then shipped to another location for eventual sale, the meat would reach the 20 retail outlet having a purple color which is typical of meat prior to exposure to oxygen. Heretofore, marketing efforts to teach the consumer about the harmlessness of the purple color have proved to be difficult. And, if the gas imp~L --hl~ film was a ~ t of a conventional package having a tray which is overwrapped or lidded 25 with a film and which contains a low oxygen atmosphere, the impermeable f ilm would have to be removed and replaced with a -2 t 78254 .
permeable film in order to allow for bloom of the meat to a bright red color prior to display for the consumer, negating to a large extent the benefits of a central processing facility.
A variety of packages have been developed in an effort to 5 provide a means for transporting meat in a low oxygen environment and for quickly and easily introducing oxygen to the meat at the retail outlet immediately prior to display to the consumer.
One approach to solving this problem has involved the development of peelable f ilms . That is, f ilms have been developed 10 which readily delaminate into p~ -hl e and impermeable portions.
Such a film is sealed to a support member, such as a tray, which contains the meat product, thereby forming a gas imperme~ble package for distribution. At the retail outlet, the gas impermeable portions are peeled from the film leaving a permeable 15 film sealed to the tray and, therefore, a gas permeable package which allows the meat to bloom to bright red because of the exchange with atmospheric oxygen.
The peelable film may extend over the contained product and be sealed to the periphery of the tray as a lid or it may be heated 2~ and draped over the product under vacuum to form to a vacuum skin package. However, for both types of packages the principal drawback is the relatively low gas trAnC~ ion rate of the permeable film portion after removal of the; - --hle portion.
That is, although the permeable portion of the peelable film has a 25 much higher gas tr~n~ ion rate than that of the entire f ilm prior to ~ela~i~atio~, 5,000 to 25,000 cc/2'/2~ hrs./~t2. I~t 73'F
as compared to 0 to 50 cc/m2/24 hrs./atm. at 73F prior to delamination, it is still too low to effect bloom of the packaged meat in a low oxygen gaseous atmosphere in a short period of time, except in areas of intimate permeable film to meat contact.
Most of the other approaches to achieving the goal of central fresh red meat processing have involved the development of a variety of dual web packages of the type having a permeable film covering the meat product and an; --hle film, which is removed at the retail outlet, covering the permeable film wherein the permeable film and the impermeable film are separate, discreet films .
Examples of these types of packages include dual overwrap packages wherein a permeable film is wrapped around the meat and its support member and an impermeable film is wrapped about the permeable film; dual lid packages which include a permeable lid and an impermeable lid sealed to the periphery of the support member;
and packages with a head space which allows for the introduction of a treating gas, typically nitrogen, carbon dioxide or some mixture of the two, between a permeable film adjacent to the meat product and an impermeable upper web. But, as is the case with the peelable films discussed above, each of these dual web packages are limited in their effectiveness by the p~ -h;~ity of the p~ -hle film. Typical gas transmission rates for commercially viable gas permeable films are 5,000 to 25,000 cc/m'/24 hrs./atm. at 73F which is too low to effect rapid red meat bloom by exchange of the low oxygen gases out and the atmospheric oxygen in.
.
A further package developed to allow for central fresh red meat processing includes a gas impermeable upper lid with a valve defined in the lid. The package may include a treating gas between the packaged meat and the upper lid during distribution which is 5 withdrawn through the valve and replaced with an oxygen-rich gas.
Although a rapid bloom is possible with this system, it has the disadvantages of requiring trained operators at the retail outlet and relatively expensive equipment to exchange each package thus negating the cost savings of a central processing facility. The 10 presence of the valve has the further disadvantage of creating a package appearance which is different from that which CUI~ rS are accustomed to seeing for meat packaging. Further, a gas space between the meat product and the impermeable film is required to maintain a bloomed color which yields an underf illed package 15 appearance.
Yet another package developed to allow for central fresh red meat processing provides for an excellent exchange of gases and rapid introduction of oxygen in which an upper imperme2ble web covers a lower permeable web which includes unsealed areas in the 20 seal of the permeable web to the tray. However, the intermittent sealed and nonsealed areas are formed by an altered sealing head which comprises a series of sealing "fingers" rather than a conventional, continuous sealing surface.
Thus, it is an ob ject of the present invention to provide a 25 package which allows for central processing of fresh red meat with mini~l processing requi~ed at re~ail.
2 1 7~254 It is yet another object of the present invention to provide a package which is similar in appearance to that which cu~ rS
are accustomed to seeing for meat packaging.
It is a further object of the present invention to provide a 5 package which allows for rapid bloom of fresh red meat.
It is yet another object of the present invention to provide a package which may be assembled, filled and sealed at a central processing facility on conventional equipment.
SUM~A~Y OF T~ INVF~TION
These as well as other objects are achieved by providing a package for a product which includes a product, an inner support member having a cavity for receiving the product and a peripheral 15 flange, an outer support member having a cavity for receiving the inner support member and a peripheral flange, a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product, open 20 ~h~nnf~ defined by the inner support member providing for a free f low of gases between the cavity of the inner support member and the cavity of the outer support member, an i ~nr~ hle f ilm enclosing the permeable film, and open r-h;lnn~ defined by the permeable film, such that the removal of the i~r ~~hle film 25 allows for a free flow of gases between the external environment and the packaged product via the open ~h~nn~ def ined by the permeable film and the channels defined by the inner support member .
Such objects are also achieved by providing a package for a product which includes a product, an inner support member having a 5 cavity formed by a base and side walls for receiving product and a peripheral flange, the side walls of the inner support member having a plurality of perforations defined therein, an outer support member having a cavity for receiving the inner support member and a peripheral flange, a permeable film sealed to the 10 upper flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product, an impermeable film enclosing the permeable film, and open ~-h~nn~l c defined by the permeable film, such that the removal of the impermeable film 15 allows for a free flow of gases between the external environment and the packaged product via the open ~-hAnn~lR and the perforations def ined within the inner support member .
RRTRl;' DRS-'RTP'I'ION OF THE nRAWTNGS
A detailed description of preferred embodiments of the invention follows, with reference to the accompanying drawings, wherein:
Fig. 1 is a perspective view of a package in accordance with 25 the present invention;
Fig. 2 is a cross-section of the package of Fig. 1;
Fig. 3 is a cross-section of another ~mho-lir-mt of the packaqe of the present invention:
Fig. 4 is a cross-section of yet another omho~lir L of the package of the present invention;
Fig. 5 is a partial cross-section of a still further t of the package of the present invention;
Fig. 6 is a partial cross-section of another ~ t of the package of the present invention:
Fig. 7 is a partial cross-section of yet another ` ';- t of the package of the present invention:
Fig. 8 is an enlarged sectional perspective view of the package of Fig. 7 during removal of the imr~ -~hle film Fig. 9 is a partial cross-section of a still further embodiment of the package of the present invention; and Fig. 10 is a partial cross-section of another embodiment of the package of the present invention.
DETATrrn DES~RTPTION OF TT~r pRr~rRRFn EMr~oDIMr~NTs The present invention is directed to a tray-type package for meat and other perishable goods which includes an outer support member or tray, an inner support memher or tray nested in the outer tray, a permeable film sealed to both the inner tray and the outer tray and an impermeable film enclosing the p~ --hlf~ film. The package most preferably includes a low oxygen gaseous atmosphere, such as a nitrogen/carbon dioxide mix. Perforations defined within the permeable f ilm between its seal to the inner tray and its seal to the outer tray and perforations defined within the tray walls of the inner tray act together to form open rh~nnPl ~ for the rapid release of the low oxygen atmosphere and introduction of oxygen to s the packaged product upon removal of the impermeable film at retail while essentially precluding contamination of the packaged product.
Looking specifically to the figures of the drawing, Figure 1 shows a package 10 in accordance with the present invention. An outer support member or tray 12 includes a base 14 and side walls 16 which define a cavity 18. A flange 20 extends outwardly from the upper periphery of the side walls and includes an outer flange portion 22 and an inner flange portion 24 separated by a depression 26. Inner support member or tray 28 includes a base 30 and side walls 32 defining a cavity 34 for receiving a product 36. An upper 15 flange 38 extends outwardly about the upper periphery of the side walls .
As is better seen in the cross-sectional view of Figure 2, inner tray 28 is received by and contained within cavity 18 of outer tray 12. Preferably, ridges 40 are formed in the base of the 20 inner tray, such that a major portion of the bott~ ~ surface of inner tray base 30 is maintained at least slightly above the uppermost surface of outer tray base 14.
As may also be seen from Figure 2, the inner tray is nP~-P~s~rily smaller than the outer tray. It is also preferred that 25 the inner tray has a height from the bottommost surface of its base ~o the ~ sur~ace of its f~ange which is less than that of . 2178254 the outer tray and which, when the inner tray is nested in the outer tray, allows for the respective flanges of the two trays to be substantially coplanar. Thus, permeable film 42 may be sealed to both flanges while maintaining a substantially flat configuration. However, it is also within the scope of the present invention to provide the flange of the inner tray either below or above the level of the outer tray f lange .
Regardless of the relative levels of the two flanges, permeable film 42 is sealed to the flange 38 of the inner tray forming an inner seal 44 and to the inner portion 24 of flange 20 of the outer tray forming an outer seal 46. T ,- --hle film 48 is sealed to the outer portion 22 of outer tray flange 20 only.
Perforations 50 are defined within permeable film 42 between inner seal 44 and outer seal 46. Perforations 52 are defined within side walls 32 and, less preferably, base 30 of inner tray 28. Thus, upon removal of the ;r~r- --hle film, open ~-hAnnPlc are defined between the external c~ Are and the packaged product allowing for a rapid introduction of oxygen and a correspon~l; nAjl y rapid blooming of a packaged meat product.
The present inventive package has the unusual advantage of allowing for a free flow of gases to and from a packaged product while essentially precluding contamination of the product. After removal of the impermeable film, any contaminants entering the package through perforations 50 deîined within the p~ --hle film are trapped at the lower portion of the package at base 14 or between base 14 and base 30 and away from the packaged product.
2 t 78254 Thus, it is preferred that ridges 40 are defined within base 30 to provide ample space for receipt of any contaminates and it is preferred that perforations are not included in base 30 of the inner tray.
llowever, for applications where a space is not desired between the two bases, ridges may be omitted as is shown in Figure 3. For such embodiment package 60 includes outer tray 62 having a base 64.
Inner tray 66 includes base 68 which rests directly on the upper surface of outer tray base 64. Similarly, where contamination is unlikely or of less concern, perforations may be defined in an inner tray base which includes ridges to allow for a f low of gases to and from the bottom side of the packaged product. Such a construction may also be preferred as a means to allow any emitted blood or other liquid, known as purge, to be drained away from the lS meat product for a neater appearance when a ~ r is viewing the package through the permeable f ilm as is shown in Figure 4 .
Package 70 includes outer tray 72 having a base 74. Inner tray 76 includes a base 78 with ridges 80 and perforations 81 defined therein. A soaker pad 82 is preferably included between the inner tray base 78 and outer tray base 74.
A further alternative P~hoA;r--~t is the provision of a single flange rather than a dual flange for the outer tray. Such may be employed when a precise means is available for sealing the permeable film to an inner portion of the single flange and for subsequently sealing the i - -hl e f ilm to an outer portion of ingle il6gge ~ di~closed i= ~pe=di~ U.S. Seri-il No.
.
That is, the primary reason a dual flange is preferred for use on the outer tray of the present invention is that it facilities the automated sealing of two separate webs to the flange. In the embodiment of Figure 6 package 90 includes outer tray 92 with flange 94. Inner tray 96 includes flange 98.
Permeable film 100 is sealed to flange 98 and to the inner periphery of flange 94. Impermeable film 102 is sealed to the outer periphery of flange 94 outboard of the seal between the permeable film and the flange.
A second circumstance under which a single flange may be employed on the outer tray of the present inventive package is when an adequate, peelable seal may be made between the i ~J~L --hle film and the permeable film. Rather than sealing the illl~ L - hle film directly to the outer tray, it is possible, with the proper selection of film c~ Ants, to form a seal directly to the permeable film which may be peeled away without disturbing the seal between the permeable film and the outer tray flange. Such a tray is set forth in Figure 5. P~ckage 110 ;nAl~ e-A outer tray 112 having flange 114. Inner tray 116 includes flange 118. Permeable film 120 is sealed to flange 118 and flange 114. T --hle film 122 is sealed to permeable film 120 and may be peeled away without disrupting the seal between permeable film 120 and flange 114.
As a further variation, a single film which is capable of delaminating into a po -hle web and an imr~ --hle web may be partially perforated therethrough, with complete perforations being formed through the permeable port on, at the appropriate location, ~t 78254 .
as is disclosed in copending U.S. Serial No. . Such a film may be sealed at the permeable 3ide thereof to the two f langes .
When the impermeable portion is ~ ;n~ted and removed, perforations formed in the permeable web between the seals with the inner tray and outer tray flanges form open channels which act with perforations in the inner tray to allow for a rapid gas exchange.
Yet a further alternative embodiment of the present invention employs a tray disclosed in copending U.S. Serial No. , which is a dual f lange tray having grooves def ined in the inner portion of the dual flange. Looking specifically to Figure 7, the outer tray 161 of package 160 has a cavity 162 and an upper flange 164 which includes inner flange portion 166 and outer flange portion 168 separated by depression 170. As above, depression 170 allows for trimming of any film sealed to the inner flange portion 166 and provides a clear delineation between the sealing area for an inner permeable film and an outer impermeable film.
In the present omho~;- t, inner flange portion 166 includes grooves 172 defined therein and spaced about the perimeter of the flange. As can be seen from the drawing of Figure 8, a top ; _ --hle film 174 is sealed to the support member at outer flange portion 168. Preferably, a peelable seal is formed between the ;~r~ --hle film 174 and outer flange portion 168 such that the outer i~.~eL --hle film may be readily removed from the package at retail .
Figure 8 is an enlarged sectional view of the upper flange 164 of package 160 upon removal of impermeable film 174. Permeable film 176 is sealed to the support member at inner flange portion 166. However, ~rooves 172 defined in inner flange portion 166 provide for open channels between the tray cavity 162 and depression 170. When impermeable film 174 is sealed to outer flange portion 168, depression 170 is enclosed, as is shown in Figure 7. However, upon removal of film 174, depression 170 and grooves 172 def ine open ~-hAnn~l c into tray cavity 162 . Inner tray 180 includes side walls 182 having perforations 184 defined there.
Thus, removal of film 174 allows for a rapid release of the low oxygen atmosphere and introduction of oxygen to the packaged product via the open channels def ined by grooves 172 and perforations 184. Therefore, by the present embodiment it is not necessary to perforate the permeable film during the packaging process .
As yet a further alternative embodiment the inner tray may include grooves defined in its single flange such that perforations within the tray side walls are not needed. Such embodiment is illustrated in the cross-sectional view of Figure 9 in which package 200 includes outer tray 202 and inner tray 204. Grooves 206 defined in the flange 208 of inner tray 204 eliminate the need for perforations in side walls 210. In combination with perforations 212 defined in permeable film 214, such grooves allow for a release of any contained low oxygen gaseous c~ re and for a rapid introduction of oxygen to the packaged meat product 216, as is shown, upon removal of an upper i -hle film.
When used in conjunction with the dual flanged tray having ~ 2 1 7825~
grooves in the inner flange portion, discussed above, perforations in both the tray side walls and the film, between the two trays, are 2voided as is shown in the cross-sectional view of Figure 10.
For that ~ t, package 220 includes outer tray 222 with dual flange 224 having an outer portion 226, an inner portion 228 and depression 230 therebetween. Inner flange portion 228 includes grooves 232. Inner tray 234 has a single flange 236 with grooves 238 defined therein. Upon removal of an upper impermeable film grooves 232 and grooves 238 provide an open channel between the external atmosphere and the packaged meat product 240, as is shown.
Regardless of the package configuration employed, it is preferred that the inner tray of the present inventive package is a solid rigid polymer such as, for example, polyester, polystyrene, high density polyethylene, or polyvinyl chloride, laminated with a sealant layer. Foamed polymers are less preferred because of possible outg~c~;n~ of oxygen and other residual gases into the low oxygen c~ re of the package. However, foamed trays which include barrier sealant films laminated to both surfaces thereof are also within the scope of the present invention.
The outer tray must act as a barrier but may be a rigid solid polymer, a barrier sealant coated polymer, a barrier sealant coated foamed polymer, or a barrier sealant coated pulp or paperboard tray. If foamed, the outer tray only requires a barrier film on the inner surface in order to prevent outgassing of residual gases into the package.
The permeable f ilm or web of the present invention is an 2 t 78254 oxygen permeable or non-barrier film or skin which may be a formable or stretchable material. Typical polymeric materials for the present permeable film may include any material which may be securely sealed and bonded to the support member, such as 5 polyethylene or any of a variety of ethylene copolymers including, for example, ethylene vinyl acetate, ethylene acrylate copolymers, ethylene acrylic acid copolymers including metal neutralized salts thereof, and ethylene alpha-olefin copolymers. Such ethylene alpha-olef ins may be heterogeneous or ht j "~US in nature . That 10 is, ethylene alpha-olefins which have been formed by conventional Zeigler-Natta catalysis and are heterogeneous in nature, such as linear low density polyethylene (LLDPE), are within the scope of the present invention as well as such copolymers which are formed by single site catalysis, such as any of a variety of forms of 15 metallocene catalyst technology, and are homogeneous in nature are also within the scope of the present invention. A preferred permeable film for use in accordance with the present invention is a symmetrical, five layer oriented film having the ~ u~;LuLe:
EVA / LLDPE / EVA / LLDPE / EVA
20 although a wide variety of permeable films may be employed.
The impermeable film or web of the present invention may be any suitable barrier layer, film or laminate which is substantially impermeable to gas such as oxygen so that a fresh meat product contained in a vacuum or other low oxygen ai -- re pocct~qc-t~c an 25 t~nh lnt-t~c~ shelf life over a package without the barrier layer.
Suitable polymeric materials having gas barrier properties for use ~ 21 78254 in the present invention include ethylene vinyl alcohol copolymers, vinylidene chloride copolymers (PVDC) such as vinylidene chloride vinyl chloride or vinylidene chloride methyl acrylate. Laminates of a sealable film and a barrier structure which includes a barrier 5 layer and a tough, non-forming material such as a biaxially oriented nylon or biaxially oriented polyester are especially preferred for use as the impermeable lidding of the present inventive packages. A preferred impermeable web has the structure:
biax nylon / PVDC // EVA / LLDPE / seal lO wherein the double slashes (//) indicate adhesive lamination of the two webs, although a variety of laminates and multilayer films may be employed as the impermeable web of the present invention.
Generally, the films or webs which may be employed in accordance with the present invention may be monolayer or 15 multilayer. Nultilayer films may be employed when all of the properties required of the f ilm cannot be achieved by a single polymeric component or a blend of polymers in a single layer. For example, an impermeable film to be sealed to a tray in all l;kf-l;h~lod will comprise a multilayer film because several 20 properties are needed including peelable sealability, oxygen barrier and impact properties, and outer abuse properties. Thus, the film employed will most likely contain three layers at a minimum: a seal layer, a barrier layer and an outer abuse layer.
Further internal layers such as adhesive layers and bulk layers may 25 also be included. Laminates of sealable films and nonforming materials such as biaxially oriented polyester or biaxially oriented nylon are also within the scope of the present invention and are widaly recognized as superior lidstocks for tray-type packages .
The foregoing description of preferred ' ~ ts of the 5 invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above t~ch; ngs or may be acquired from practice of the invention. The ~ ;r--~ts were 1~ chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various ~ ; r S and with various modif ications as are suited to the particular use contemplated. It is intended that the scope of the invention be 15 def ined by the claims ~rp-~n~led hereto, and their e~uivalents .
Claims (28)
1. A package for a product, comprising:
a product;
an inner support member having a cavity for receiving the product and a peripheral flange;
an outer support member having a cavity for receiving the inner support member and a peripheral flange;
a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product;
open channels defined by the inner support member providing for a free flow of gases between the cavity of the inner support member and the cavity of the outer support member;
an impermeable film enclosing the permeable film; and open channels defined by the permeable film, such that the removal of said impermeable film allows for a free flow of gases between the external environment and the packaged product via said open channels defined by the permeable film and said open channels defined by the inner support member.
a product;
an inner support member having a cavity for receiving the product and a peripheral flange;
an outer support member having a cavity for receiving the inner support member and a peripheral flange;
a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product;
open channels defined by the inner support member providing for a free flow of gases between the cavity of the inner support member and the cavity of the outer support member;
an impermeable film enclosing the permeable film; and open channels defined by the permeable film, such that the removal of said impermeable film allows for a free flow of gases between the external environment and the packaged product via said open channels defined by the permeable film and said open channels defined by the inner support member.
2. The package set forth in claim 1 wherein said open channels defined by said inner support member comprise perforations formed therein.
3. The package set forth in claim 1 further including grooves defined in said peripheral flange of said inner support member.
4. The package set forth in claim 3 wherein said open channels defined by said inner support member are defined by the grooves defined in said peripheral flange of the inner support member and the permeable f film sealed to said f lange .
5. The package set forth in claim 1 wherein said open channels defined by said permeable film are perforations defined within said permeable film between said first sealed area and said second sealed area.
6. The package set forth in claim 1 wherein said flange of said outer support member is a dual flange comprising an inner flange portion, an outer flange portion and a depression therebetween.
7. The package set forth in claim 6 wherein said permeable film is sealed to said flange of said outer support member at said inner flange portion forming of said second sealed area and said impermeable film is sealed to said flange of said outer support member at said outer flange portion.
8. The package set forth in claim 7 further including grooves defined in said inner flange portion.
9. The package set forth in claim 9 wherein said open channels defined by said permeable film are defined by said permeable film sealed to said inner flange portion and said grooves defined in said inner flange portion.
10. The package set forth in claim 7 wherein said open channels are perforations defined in said permeable film between said first sealed area and said second sealed area.
11. The package set forth in claim 1 wherein said flange of said outer support member is a single flange.
12. A package for a product, comprising:
a product;
an inner support member having a cavity formed by a base and side walls for receiving the product and a peripheral flange, the side walls of said inner support member having a plurality of perforations defined therein;
an outer support member having a cavity for receiving the inner support member and a peripheral flange;
a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product;
an impermeable film enclosing the permeable film; and open channels defined by the permeable film, such that the removal of said impermeable film allows for a free flow of gases between the external environment and the packaged product via said open channels and the perforations defined within said inner support member.
a product;
an inner support member having a cavity formed by a base and side walls for receiving the product and a peripheral flange, the side walls of said inner support member having a plurality of perforations defined therein;
an outer support member having a cavity for receiving the inner support member and a peripheral flange;
a permeable film sealed to the flange of the inner support member forming a first sealed area and sealed to the flange of the outer support member forming a second sealed area for enclosing the product;
an impermeable film enclosing the permeable film; and open channels defined by the permeable film, such that the removal of said impermeable film allows for a free flow of gases between the external environment and the packaged product via said open channels and the perforations defined within said inner support member.
13. The package set forth in claim 12 wherein said open channels are perforations defined within said permeable film between said first sealed area and said second sealed area.
14. The package set forth in claim 12 wherein said flange of said outer support member is a dual flange comprising an inner flange portion, an outer flange portion and a depression therebetween.
15. The package set forth in claim 14 wherein said permeable film is sealed to said flange of said outer support member at said inner flange portion forming said second sealed area and said impermeable film is sealed to said flange of said outer support member at said outer flange portion.
16. The package set forth in claim 15 further including grooves defined in said inner flange portion.
17. The package set forth in claim 16 wherein said open channels are defined by said permeable film sealed to said inner flange portion and said grooves defined in said inner flange portion.
18. The package set forth in claim 15 wherein said open channels are perforations defined in said permeable film between said first sealed area and said second sealed area.
19. The package set forth in claim 12 wherein said flange of said outer support member is a single flange.
20. The package set forth in claim 19 wherein said permeable film is sealed to an inner periphery of said single flange and said impermeable film is sealed to an outer periphery of said single flange.
21. The package set forth in claim 19 wherein said permeable film is sealed to said single flange and said impermeable film is sealed to said permeable film.
22. The package set forth in claim 21 wherein the force required to break the seal between said impermeable film and said permeable film is less than the force required to break the seal between said permeable film and said single flange.
23. The package set forth in claim 22 wherein said impermeable film is sealed to said permeable film, such that said impermeable film may be peeled away from said permeable film.
24. The package set forth in claim 1 wherein the base of said inner support member includes ridges defined at the bottommost surface thereof.
25. The package set forth in claim 24 wherein said base further includes a plurality of perforations defined therein.
26. The package set forth in claim 25 further including a soaker pad between the base of said inner support member and the base of the outer support member.
27. The package set forth in claim 12 wherein said base further includes a plurality of perforations defined therein.
28. The package set forth in claim 27 further including a soaker pad between the base of said inner support member and the base of the outer support member.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US47080895A | 1995-06-06 | 1995-06-06 | |
US08/470,808 | 1995-06-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2178254A1 true CA2178254A1 (en) | 1996-12-07 |
Family
ID=23869134
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2178254 Abandoned CA2178254A1 (en) | 1995-06-06 | 1996-06-05 | Dual tray, dual web package having improved gaseous exchange |
Country Status (3)
Country | Link |
---|---|
AR (1) | AR002392A1 (en) |
BR (1) | BR9602707A (en) |
CA (1) | CA2178254A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115108174A (en) * | 2022-06-23 | 2022-09-27 | 浙江强盟复合材料有限公司 | High-sealing-property food preservative film and preparation method thereof |
-
1996
- 1996-06-05 CA CA 2178254 patent/CA2178254A1/en not_active Abandoned
- 1996-06-07 AR ARP960103036A patent/AR002392A1/en unknown
- 1996-06-07 BR BR9602707A patent/BR9602707A/en not_active Application Discontinuation
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115108174A (en) * | 2022-06-23 | 2022-09-27 | 浙江强盟复合材料有限公司 | High-sealing-property food preservative film and preparation method thereof |
CN115108174B (en) * | 2022-06-23 | 2023-10-13 | 浙江强盟复合材料有限公司 | High-tightness food preservative film and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
BR9602707A (en) | 1998-09-08 |
MX9602197A (en) | 1997-09-30 |
AR002392A1 (en) | 1998-03-11 |
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FZDE | Dead |