CA2131882A1 - Double seal peelable barrier overwrap - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A package for a product includes a support member supporting the product; a permeable film sealed to the support member at a first seal for enclosing the product;
and an impermeable film sealed to the support member at a second seal for enclosing the permeable film whereby breaking of the second seal and removal of the impermeable film is accomplished without breaking the first seal.

Description

~ `` 2~;3~8~2 BACKGROUND OF T~E I~JENTION

This invention relates generally to packages having a peelable film. Particularly, the present invention relates to packages wherein a barrier layer or film may be peeled and separated from a non-i~arrier film and to a method for packing a product in a pac~age having a peelable barrier film.
In U.S. Pat. No. 3,574,6~ which issued on Apr. 13, 1971 to Carl Frederick Weinke, a package for a method of pack.agin~ meats is disclosed. The package includes an inner oxygen-permea~le mem~er which may ~e gas flushed or evacuated. The package preserves the freshness of the meat until the meat is ready to be marketed to the consumer. For marketing, the outer wrapper is removed and the inner package is displayed to the consumer. Being oxyq~n-pcrmeable, the inner wrapper admits oxygen ~o the interior of the package causing the fresh meat product to change to a ¦ bright red color which the consumer associates with! freshness. ~he inner pouch of the WsinXe package may - .
consist~o~ polyethylene ~ilm and the outer pouch may be cellophane fil~ with a coating of saran (vinylidene chloxide copolymer.) Another patent showing portions of fresh meat individually packaged in oxygen permea~le plastic film and .

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21 3~ 2 inserted into an outer contalner of impermeable film is U.S.
Pat. No. 3,681,092 whic~ issued to Oliver R. Titchnell et al, on Aug. 1, 1972.
Another prior art pac~age is described is U.S. Pat. No.
3,713,849 which issued to Paul E. Grindrod et al. on Jan 30, 197~. In the Grindrod et al. patent a fresh meat pac~age having an outer oxygen impermeable lamina which is readily and entirely peelable from an inner oxygen-permeable lamina is disclosed. The pac.~age includes means for initiating the peeling separation along an edge of the package. The outer oxygen barrier main~ains meats in well preserved condition in spite of the purplish color which has low consumer appeal. Shortly prior ~o display for sale to the consumer the outer lamina is removed by the retailer and the product develops a healthy,,bright red "bloom" due to the high oxygen through-put of the inner remaining film package. The material disclosed in Grindrod et al. is a laminate of PVC/Saran and EVA/Saran. (EVA designates ethylene/vinyl-acetate copolymer and PVC designates polwinyl-chloride. ) Th~ EVA and PVC la~ers are the inner layers and at the periphery of the package they are sealed together. The saran layers can be readily peeled ~rom the respective EV~
or PVC layers with gripping tabs that arQ provided.
Yet another peelable package i5 shown in U~S. Pat. No.
4,055,672 which issued on Oct. Z5, 1977 to Arthur Hir~ch et ,i~: - : ~ : -- 2 1 3 ~
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al. In the Hirsch et al. patent a semi-rigid preformed tray of oxygen imp~rmeable material is formed, a meat product placed therein, and then thè tray is sealed around its upper periphery or flange area by a composite lid which has an inner layer of oxygen permea~le material, an adhesive layer, and an outer layer of oxygén impermeable material. When the pac~aye is ready for retail display, in order that oxygen I can reach the ~resh meat packaged withln permeable material, ¦ the outer, impermeable lid is peeled away so that the oxygen can penetrate through the remaininy portion of the lid.
In the foregoing Grindrod et al. and Hirsch et al.
patents, a complication arises in that the non-barrier layer must be sufficiently adhered to the tray member so that force of removing the barrier layer, especially the force required to initiate removal of the barrier layer, does not ¦ damage or remove the non-barrier layer.
It is the principal object of the invention to provide a peelable barrier film pac~age wherein removal of the barrier film does not adversely affect the non-barrier film or its seal to-an underlying support or tray member.
Numerous peelable barrier layer pac~ages are prepared with a co-extrusion or laminating process wherein a formable composite of the various layers is produced and applied to a product.

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- -- ' ' 2 1 3 l 8 After removal o~ the barrler layer, the package must b~
marked or tagged by the grocer before it i5 placed in a display case. It is another object of the invention to provide a package wherein a label is placed on the non- ~
barrier layer ~etween the two layers so that the label is ~-exposed upon removal of the ~arrier layer.
It is a further object of the invention to pr~vide a method for manufacturing a barrier pac~aqe in accordance with the invention.
other objects and advantag~es will appear hereinbelow.

SUMMARY OF THE INVENTIOM ;~

In accordance with the invention, a peelable barrier layer pac~age for a product, par~icularly a ~resh red meat product, comprises a support member supporting the product;
a permeable film means sealed to the support member at a first seal for enclosing the product; and an impermeable f'ilm means sealed to the support member at a second seal for enclosing the permeable film means whereby breaking of the second seal and removal of the impermeable film means is accomplished without breaking the first seal.
According to the invention the package is formed by a method comprising the steps o~ prcviding a support member having a product supported thereon; sealing a permeable film 3 18 ~

to the support member at a firs~ seal so as to enclose the product; and sealing an impe~meable film to the support member at a second seal so as ~o enclose the permeable film, wher~by breaXing of the second seal and peeling of the impermeable film means is accomplished without breaking the first seal.

BRIEF DESCRIPTIOM OF TUE DR~WING5 A detailed description of Freferr~d embodiments of the invention follows, with reference to the accompanying drawinqs, ~herein:
Fig. 1 is a cross-section of a package, according to the invention;
Fig. 2 is an enlarged sectional view of a flan~e of a package, according to the invention, showing the seals of ¦ 15 the permea~le and imperm~able films;
Fig. 3 is another embodiment of the inventlon, similar to Fig. 2, and including a tab for initia~ing peel of the peelable impermeable film, according to the invention;
Fig. 4 is an alternate embodiment similar to Fig. 2;
and Flg. S is a portion of a packaged top surface of a product including a label on the permeable film, according to the invention.

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233:~882 DETAILED DESCRIPTION

The invention relates to a package for products, particularly fresh red meat products, ha~ing an inner non~
~arrier film or layer, and a peelable ~uter barrier film or S layer. .
Fig. 1 illustrates a pac~age 10 in accordance with the invention. According to the invention, package 10 comprises a support member 1~ supporting a product 12 and having a permeable film 16 enclosing the product and sealed to the support member 14, and a peelable impermeable ~ilm 18 se~led to the support member 14 and enclosing permeable film 16.
The permeable film 16 is preferably a stretch ~ilm ~pplied over the product and sealed to the support member 14;
however, the film could be a skin film formed around the product by vacuum or differential air pressure, that is, a ::
vacuum skin packaging film.
Product 12 packaged in this manner provides fresh red meat with a longer shelf life while peelable impermeable film 18 is in place. Impermeable film 18 can be peeled so that oxygen permeates permeable layer 16 and oxygenates the -fresh red meat and provides it with a bright red color or "bloom" for placement in a ret~il display case. The bright 213188?- i ~
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red "~loom" is desirable as t~e consumer assosiates a bright red color with freshness.
According to the invention, permeable film 16 is sealed .~
to support member 14 through any means known to those skilled in the art so as to enclose product 12. Preferably, permeable film 16 is heat séaled to support member 14 around a periphery of product 12 so that a por~ion 20 of support`-~
mem~er or tray 14 is not covered by permeable film 16.
Imper~eable film 18 is then sealed to support member 14 ;~
around a periphery of the seal ~f permeable film 16 so as to enclose permeable film 16. Package 10 p~eferably has an -inner space 15 which is evacuated or flushed with a low oxygen atmosphere so as to improve the shelf life of ;~
products contained therein.
According to the invention, impe~meable film 1~ and ,, permeable ~ilm 16 are sealed to tray 14 in a non-overlapping ~; fashion so that the seal of impermeable film 18 can be broken and impermeable film 18 peeled ~ithout adversely affecting the integrity of permeable film 16. Fig. 2 shows an enlarged portian of tray 14 with im~ermeable film 18 and ~ _ . ,. , ._ , permeable ~ilm 16 sealed thereto.
Tray 14 preferably has upstanding wall portions 22 with a flange 24 extending outwardly there~rom, pre~erably around substantially the entire periphery of tray 14. According to the invention, permeable film 16 is sealed to flange 24 at a .

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;~ first seal 26, preferably formed about an inner edge of flange 24. Impermeable ~ilm 18 is then pre~era~ly applied over permeable film 16 and sealed to tray 14 at a second seal 28, pre~erably formed along an outer edge, outside of first seal 26, so that, advantageously, second seal 28 can be ~roken for peeling without significant forces being exerted upon or transferred to the second seal 28.
The sealing of permeable film 16 and impermea~le film 18 is such that first seal 26 defines a .irst perimeter with tray 14 and second seal 28 de.ines a second perimeter with tray 14 which is larger and entirely encloses the first perimeter without overlapping same. In ~his manner, peeling of impermeable film 18, with the expected force necessary to breaX seal 28, does not transmit or translate the breaking force to first seal 26. Seal 26 and permeable film 16 are -t~erefore left intact on package 10 as desired.
Fig. 3 illustrates a similar embodiment wherein a tab 30 is provided to form a flap 31 ~y which impermeable fi:Lm 18 can be removed from package 10 when desired. Any suitable tab or other structure may be incorporated so as to facilitate peeling.
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It is desirable to pr~vide package 10 having a "stretch wrapped" appearance. In this regard, impermeable ~ilm 13, as shown in Fig. 4, may be sealed to flange 24 at a bottom surface 32 thereof. In ~his manner, seal 28a is not visible - 21318~-2 from the tsp and package 10 has the appearance of having been stretch wrapped. ~ote that in this configuration as well, seal 28a can be broken and impermeable ~ilm 18 peeled and removed without damaging permeable film 16.
Permeable film 16 is an oxygen permeable or non-barrier film or skin which may ~e f'ormable or stretchable material.
T~lpical materials for permeable film 16 include any material which may ~e securely sealed and bonded to tray 14, such as ethylene vinyl acetate (EVA), polyethylene film, Surlyn, stretch olefin film, blown film and the like. Further, permeable film 16 may be a single or multilayer film having other layers for numerous other purposes.
Permeable film 16 preferably admits at least about 2000 cc of a gas (oxygen) per square meter of the material per 24 hour period at a temperature of 73 F. This oxygen permeability or non-barrier characteristic is desirable so that, when impermeable film 18 is peeled, oxygen can quic~ly ~` ~ permeate package 10 and oxygenate the fresh meat product to provide the desirable bright red "bloom" associated by the consumer with freshness.
Impermeable ~ilm 18 may be any suitable barrier or laminate film which is substantially impermeable to gas such as oxygen so that a fresh meat product contained in a vacuum or other atmosphere in package 10 possesses an enhanced shel~ e over a pac~age without the barrier layer.
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2 ~ 8 2 Impermeable film 18 may suitabl~ be for~able or may be str~tched for application to product 12, and may like~ise be a si~gle or multi layer film having other layers for other -~ ;
purposes as desired.
Imper~ea~le ~ilm 18 ls preferably substantially impermeable to gas, especially oxygen, and preferably allows less than or equal to about 50 cc of oxygen to pass per s~uare meter per 24 hour period at a te~perature of 73 F.
It is noted that, because i~permeable film 18 is to be removed prior to display to the consu~e-, the appearance of impermeable film 18 is not critical. Thus, impermeable film 18 could acceptably be wrinkled, opa~ue, or translucent without adverse consumer impact. Impermeable film 18 is, howeverl preferably sufficiently translucent so as to allow the product 12 contained in package 10 to be identlfied.
Suitable impermeable films for use in the present invention include ethylene vinyl alcohol copoly~ers, vinylidene ~ -chloride copolymers, ethylene-vinyl alcohol or hydrolyzed ethyl/vinyl acetate (EVO~) and others known im the art.
Tray 14 must be a barrier type tray, because package 10 is to be a barrier package. Thus, tray 14 is preferably laminated or otherwise provided with a barrier film or layer contained therein for inhibiting the flow of gases through the tray. Alternatively, tray 14 may itself be provided from a substantially impermeable material.

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Tray 14 prefera~ly has upstanding walls 22 which are not as high as the product 12 to be packaged. This allows films 16, 1~ to be skin wrapped, stretch wrapped or formed ,~ or otherwise intimately wrapped over a top surface 36 (Fig.
~i 5 1) of the product which also provides impxoved consumer appeal.
Fig. 5 illustrates an alternate emsodiment wherein a label 34 or tag or the like is disposed between permeable film 16 and impermeable film 18 for use in properly labelling product 12 when pac~age 10 is to be displayed for sale. Label 34 is preferably a~fixed to permeable film 16 so that it remains in placP upon permeable film 16 when impermeable film 18 is remo~ed.
Product 12 can be packaqed, according to the invention, by positioning the product on tray 14 or any other suitable barrier support member. Product 12 may ~e positioned one at a time on individual trays or may be positioned in rows or other patterns on sheets of support tray material to be subsequently cut into individual unit~, all as is known in the art.
Permeable film 16 is then applied as a stretch film or ski~ and sealed around the perimeter of product 12 to tray 14 so as to enclose product 12. Excess permeable film outside of seal 26 is preferably trimmed away to expose the portion 20 of tray 14, preferably on flange 24, to which the `1 ~

`) ~ ~ `: ` ` ~ ' ' ' ' ` - 2-~3~2 impermeable film 18 i5 to be seaLed. Label 34 may be affixed to permeable film 16 if desired. Impermeable film 18 is then seaLed over permeable film 16 to tray 14 at a seal 28, 28a which is peripherally outside o~ and does not S overlap seal 26 of permeable film 16. Package 10 ls then ready for shlpping or sto~ase and, due to the ~arrier layer, possesses an excellent shelf life.
When pac~age 10 ls to be dlsplayed rOr sale, lmpermeable film 18 is easily removed without risk of damage to permeable film 16 or seal 2~. In this manner, package 10 is provided and requires a minimal amount of handling to provide a package having excellent consumer appeal.
Permeable film 16 and support member 14 define an inner space 15 of package 10 which, accordlng to the invention, may be evacuated or flushed with a low oxygen gas before sealing the permeable ~ilm 16 to the support member 14~ The low oxygen gas preferably has an oxygen content of less than or equal to abcut 0.05~ by volume.
It is noted tha~, as is well known in the art, films 16, 18 may suitably 1nclude additional film layers suited to other specific purposes such as abuse layers, moisture barrier layers, light barrier layers, and the like.
Thus provided is a pac~age and method for pacXaging which yields a package having impermeable and permeable films wherein the impermeable film provides enhanced shelf life and is easily removable without adversely affecting the integrity of the inner permeable film.
It i5 to be understocd that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which axe susceptible of modification cf form, size, arrangement of parts and details of cperation. The invention rather is intended to encompass all such modifications which are within its spirit and scope 2s defin^d by the c1aims.

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Claims (22)

1. A package for a product, comprising:
a support member supporting the product;
a permeable film means sealed to the support member at a first seal for enclosing the product; and an impermeable film means sealed to the support member at a second seal for enclosing the permeable film means whereby breaking of the second seal and removal of the impermeable film means is accomplished without breaking the first seal.

2. A package according to claim 1, wherein the first seal defines a first perimeter with the support member and the second seal defines a second perimeter with the support member which is larger than the first perimeter and which encloses the first perimeter.

3. A package according to claim 1, wherein the support member comprises a barrier tray member having upstanding wall portions and a flange portion extending outwardly from the wall portions, wherein the first seal is located at an inner edge of the flange and the second seal is located at an outer edge of the flange.

4. A package according to claim 3, wherein the product extends above the wall portions of the tray.

5. A package according to claim 4, wherein the permeable film and the impermeable film contact each other and, in combination, contact at least a top portion of the product.

6. A package according to claim 1, further including tab means for rupturing the second seal and for initiating peel of the impermeable film from the permeable film.

7. A package according to claim 1, wherein the support member is a heat sealable oxygen barrier tray.

8. A package according to claim 1, wherein the product is a fresh red meat product.

9. A package according to claim 1, wherein the permeable film means and the support member define an inner space of the package and wherein the inner space is substantially free of oxygen.

10. A package according to claim 1, wherein the first seal and the second seal are heat seals.

11. A package according to claim 1, further comprising label means for identifying the product, the label means being disposed between the permeable film and the impermeable film.

12. A method for packaging a product, comprising the steps of:
providing a support member having a product supported thereon;
sealing a permeable film to the support member at a first seal so as to enclose the product; and sealing an impermeable film to the support member at a second seal so as to enclose the permeable film whereby breaking of the second seal and peeling of the impermeable film means is accomplished without breaking the first seal.

13. A method according to claim 12, further including sealing the first so as to define a first perimeter with the support member and sealing the second seal so as to define a second perimeter with the support member which encloses the first perimeter.

14. A method according to claim 12, further including trimming the permeable film around the first seal before sealing the impermeable film.

15. A method according to claim 12, further including providing tab means for rupturing the second seal and for peeling the impermeable film from the permeable film.

16. A method according to claim 12, further including sealing by heat sealing.

17. A method according to claim 12, further including providing a support member comprising a tray having wall portions and a flange portion extending outwardly from the wall portions wherein the first seal is provided at an inner edge of the flange portion and the second seal is provided at an outer edge of the flange portion.

18. A method according to claim 17, further including providing the second seal at a bottom surface of the outer edge of the flange portion.

19. A method according to claim 12, further including evacuating an inner space defined between the permeable film and the support member of oxygen.

20. A method according to claim 12, further including flushing an inner space defined between the permeable film and the support member with a low oxygen gas prior to sealing the permeable film.

21. A method according to claim 20, including flushing with a low oxygen gas containing oxygen in an amount less than or equal to about 0.05% by volume.

22. A method according to claim 12, further including affixing a label means for identifying the product to the permeable film before sealing the impermeable film.