NZ264441A

NZ264441A - Package for product, such as meat, with removable impermeable film overlying permeable film

Info

Publication number: NZ264441A
Application number: NZ26444194A
Authority: NZ
Inventors: Henry Walker Stockley; James Akers Mize
Original assignee: Grace W R & Co
Priority date: 1993-09-14
Filing date: 1994-09-12
Publication date: 1996-09-25
Also published as: CA2131882A1; BR9403546A; AU7292594A; AU693103B2

Description

2 6 4 4 4 1 Priority Date(s): Complete Specification Filed; Class: 6 bg.g.as ] o t».

SEP 896 Publication Dat$...

P.O. Journal No: !±®& N.Z. PyiTr.-.y '."".""riQj: 1 2 SEP 1994 RECEIVED NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION DOUBLE SEAL PEELABLE BARRIER OVERWRAP PACKAGE We, W R GRACE & CO-CONN, a corporation organized and existing under the laws of the state of Connecticut, USA of 1114 Avenue of the Americas, New York, NY 10036-7794, United States of America hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - •• 26 4 4 4 « BACKGROUND OF THE INVENTION 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 5 and separated from a non-barrier film and to a method for packing a product in a package having a peelable barrier film.

In U.S. Pat. No. 3,574,642 which issued on Apr. 13, 1971 to Carl Frederick Weinke, a package for a method of 10 packaging meats is disclosed. The package includes an inner oxygen-permeable member which may be 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 15 package is displayed to the consumer. Being oxygen- permeable, the inner wrapper admits oxygen to the interior of the package causing the fresh meat product to change to a bright red color which the consumer associates with freshness. The inner pouch of the Weinke package may 20 consist "of polyethylene film and the outer pouch may be cellophane film with a coating of. saran (vinylidene chloride copolymer.) Another patent showing portions of fresh meat individually packaged in oxygen permeable plastic film and 2 2 6 4 4 4 1 * ;inserted into an outer container of impermeable film is U.S. Pat. No. 3,681,092 which issued to Oliver R. Titchnell et al, on Aug. 1, 1972. ;Another prior art package is described is U.S. Pat. No. ;5 3,713,849 which issued to Paul E. Grindrod et al. on Jan 30, ;1973. In the Grindrod et al. patent a fresh meat package having an outer oxygen impermeable lamina which is readily and entirely peelable from an inner oxygen-permeable lamina is disclosed. The package includes means for initiating the 10 peeling separation along an edge of the package. The outer oxygen barrier maintains meats in well preserved condition in spite of the purplish color which has low consumer appeal. Shortly prior to 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 polyvinyl-chloride.) 20 The EVA and PVC layers are the . inner layers and at the periphery of the package they are sealed together. The saran layers can be readily peeled from the respective EVA or PVC layers with gripping tabs that are provided. ;Yet another peelable package is shown in U.S. Pat. No. 25 4,055,672 which issued on Oct. 25, 1977 to Arthur Hirsch et ;3 ;2S 4 4 ;4 1 ;al. In the Hirsch et al. patent a semi-rigid preformed tray of oxygen impermeable material is formed, a meat product placed therein, and then the tray is sealed around its upper periphery or flange area by a composite lid which has an inner layer of oxygen permeable material, an adhesive layer, and an outer layer of oxygen impermeable material. When the package is ready for retail display, in order that oxygen can reach the fresh meat packaged within permeable material, the outer, impermeable lid is peeled away so that the oxygen 10 can penetrate through the remaining 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 package wherein removal of the barrier film does not adversely affect the non-barrier film 20 or its seal to-an underlying support or tray member. ;Numerous peelable barrier layer packages are prepared with a co-extrusion or laminating process wherein a formable composite of the various layers is produced and applied to a product. ;4 ;264441 ;After removal of the barrier layer, the package must be marked or tagged by the grocer before it is 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 between the two layers so that the label is exposed upon removal of the barrier layer. ;It is a further object of the invention to provide a method for manufacturing a barrier package in accordance with the invention. ;Other objects and advantages will appear hereinbelow. ;SUMMARY OF THE INVENTION ;In accordance with the invention, a peelable barrier layer package for a product, particularly a fresh red meat product, comprises a support member supporting the product; ;a permeable film means, having an oxygen transmission rate of at least 2000 cc/m2/24 hours at 73°F, sealed to the support member at a first seal for enclosing the product; ;and an impermeable film means, having an oxygen transmission rate of no more than 50 cc/m2/24 hours at 73°F, sealed to the support member at a second seal for enclosing the permeable film means, wherein the second seal encloses but does not overlap the first seal, 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 of providing a support member having a product supported thereon; sealing a permeable film (as defined above) ;N.Z. PATf:,\1 O; !\. ;2 - AUG 1996 ;RECEIVED ;10 ;264 4 4 1 ;to the support member at a first seal so as to enclose the product; and sealing an impermeable film (as defined above) to the support member at a second seal so as to enclose the permeable film, wherein the second seal encloses but does not overlap the first seal, whereby breaking of the second seal and peeling of the impermeable film means is accomplished without breaking the first seal. ;BRIEF DESCRIPTION OF THE DRAWINGS ;A detailed description of preferred embodiments of the invention follows, with reference to the accompanying drawings, wherein: ;Fig. 1 is a cross-section of a package, according to the invention; ;Fig. 2 is an enlarged sectional view of a flange of a package, according to the invention, showing the seals of the permeable and impermeable films; ;Fig. 3 is another embodiment of the invention, similar to Fig. 2, and including a tab for initiating peel of the peelable impermeable film, according to the invention; ;Fig. 4 is an alternate embodiment similar to Fig. 2; ;and ;Fig. 5 is a portion of a packaged top surface of a product including a label on the permeable film, according to the invention. ;2 - AUG 1996 ;2 6 4 4 4 1 ;DETAILED DESCRIPTION ;The invention relates to a package for products, ^ particularly fresh red meat products, having an inner non- ;barrier film or layer, and a peelable outer barrier film or 5 layer. ;Fig. l illustrates a package 10 in accordance with the invention. According to the invention, package 10 comprises a support member 14 supporting a 'product 12 and having a permeable film IS enclosing the product and sealed to the 10 support member 14, and a peelable impermeable film 18 sealed to the support member 14 and enclosing permeable film 16. The permeable film 16 is preferably a stretch film applied over the product and sealed to the support member 14; ;/ ;however, the film could be a skin film formed around the 15 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 ' 20 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 retail display case. The bright ;7 ;264 4 4 1 ;red "bloom" is desirable as the consumer associates 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 sealed to support member 14 around a periphery of product 12 so that a portion 20 of support member or tray 14 is not covered by permeable film 16. ;Impermeable film 18 is then sealed to support member 14 10 around a periphery of the seal of permeable film 16 so as to enclose permeable film 16. Package 10 preferably 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, impermeable film 18 and ;/ ;permeable film 16 are sealed to tray 14 in a non-over lapping fashion so that the seal of impermeable film 18 can be broken and impermeable film 18 peeled without adversely affecting the integrity of permeable film 16. Fig. 2 shows 20 an enlarged portion of tray 14 with impermeable film 18 and permeable film 16 sealed thereto. ;Tray 14 preferably has upstanding wall portions 22 with a flange 24 extending outwardly therefrom, preferably around substantially the entire periphery of tray 14. According to 25 the invention, permeable film 16 is sealed to flange 24 at a ;8 ;26 4 4 ;first seal 26, preferably formed about an inner edge of flange 24. Impermeable film 18 is then preferably applied over permeable film 16 and sealed to tray 14 at a second seal 28, preferably formed along an outer edge, outside of ) 5 first seal 26, so that, advantageously, second seal 28 can be broken for peeling without significant forces being exerted upon or transferred to th'e first seal 26. ;The sealing of permeable film 16 and impermeable film 18 is such that first seal 26 defines a first perimeter with 10 tray 14 and second seal 28 defines a second perimeter with tray 14 which is larger and entirely encloses the first perimeter without overlapping same. In this manner, peeling of impermeable film 18, with the expected force necessary to break seal 28, does not transmit or translate the breaking force to first seal 26. Seal 2 6 and permeable film 16 are therefore left intact on package 10 as desired. ;Fig. 3 illustrates a similar embodiment wherein a tab 30 is provided to form a flap 31 -by which impermeable film 18 can be removed from package 10 when desired. Any 20 suitable tab or other structure may be incorporated so as to facilitate peeling. ;It is desirable to provide package 10 having a "stretch wrapped" appearance. In this regard, impermeable film 18, as shown in Fig. 4, may be sealed to flange 24 at a bottom 25 surface 32 thereof. In this manner, seal 28a is not visible ;2 ~ AUG 1996 ;received ;264 44 1 ;from the top and package 10 has the appearance of having been stretch wrapped. Note that in this configuration as well, seal 28a can be broken and impermeable film 18 peeled and removed without damaging permeable film 16. '5 Permeable film 16 is an oxygen permeable or non-barrier film or skin which may be formable or stretchable material. Typical materials for permeable film 16 include any material which may be securely sealed and bonded to tray 14, such as ethylene vinyl acetate (EVA), polyethylene film, Surlyn, 10 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 fix»n 16 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 quickly permeate package 10 and oxygenate the fresh meat product to ^ provide the desirable bright red "bloom" associated by the ;20 consumer with freshness. ;Impermeable film 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 25 shelf life over a package without the barrier layer. ;10 ;N.Z. PA; i"; "1 ;2 - AUG 1996 ;2 6 4 4 * i Impermeable film 18 may suitably be formable or may be stretched for application to product 12, and may likewise be a single or multi layer film havi.ng other layers for other purposes as desired.

Impermeable film 18 is substantially impermeable to gas, especially oxygen, and allows less than or equal to about.50 cc of oxygen to pass per square meter per 24 hour period at a temperature of 73° F.

It is noted that, because impermeable film 18 is to be removed prior to display to the consumer, the appearance of impermeable film 18 is not critical. Thus, impermeable film 18 could acceptably be wrinkled, opaque, or translucent without adverse consumer impact. Impermeable film 18 is, however, preferably sufficiently translucent so as to allow the product 12 contained in package 10 to be identified. Suitable impermeable films for use in the present invention include ethylene vinyl alcohol copolymers, vinylidene chloride copolymers, ethylene-vinyl alcohol or hydrolyzed ethyl/vinyl acetate (EVOH) and others known in 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. 11 Tray 14 preferably has upstanding walls 22 which are not as high as the product 12 to -be packaged. This allows films 16, 18 to be skin wrapped, stretch wrapped or formed or otherwise intimately wrapped over a top surface 36 (Fig. 1) of the product which also provides improved consumer appeal.

Fig. 5 illustrates an alternate embodiment 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 package 10 is to be displayed for sale. Label 34 is preferably affixed to permeable film 16 so that it remains in place upon permeable film 16 when impermeable film 18 is removed.

Product 12 can be packaged, according to the invention, by positioning the product on tray 14 or any other suitable barrier support member. Product 12 may be 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 units, all as is known in the art.

Permeable film 16 is then applied as a stretch film or skin and sealed around the perimeter of product 12 to tr:iy 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 12 26 4 4 4 impermeable film 18 is to be sealed. Label 34 ma/ be affixed to permeable film 16 if desired. Impermeable film 13 is then sealed over permeable film 16 to tray 14 at a seal 28, 28a which is peripherally outside of and does not overlap seal 26 of permeable film 16. Package 10 is then ready for shipping or storage and, due to the barrier layer, possesses an excellent shelf life.

When package 10 is to be displayed for sale, impermeable film 18 is easily removed without risk of damage 10 to permeable film 16 or seal 26. 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, according to the invention, may be evacuated or flushed with a low oxygen gas before / sealing the permeable f ilm 16 to the support member 14. The low oxygen gas preferably has an oxygen content of less than or equal to about 0.05% by volume.

It is noted that, as is well known in the art, films 20 16, 18 may suitably include 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 package and method for packaging which yields a package having impermeable and permeable 25 films wherein the impermeable film provides enhanced shelf 13 r 26 4 4 life and is easily removable without adversely affecting the integrity of the inner permeable film.

It is to be understood 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 are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims. 14

Claims

264 44 1 WHAT ,WWE CLAIM IS

1. A package for a product, comprising:

a support member supporting the product;

a permeable film means, having an oxygen transmission rate of at least 2000 cc/m2/24 hours at 73°F, sealed to the support member at a first seal for enclosing the product; and an impermeable film means, having an oxygen transmission rate of no more than 50 cc/m2/24 hour at 73°F, sealed to the support member at a second seal for enclosing the permeable film means, wherein the second seal encloses but does not overlap the first seal, 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.

26 4 4 4

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.

16

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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, having an oxygen transmission rate of at least 2000 cc/m2/24 hours at 73°F, to the support member at a first seal so as to enclose the product; and sealing an impermeable film, having an oxygen transmission rate of no more than 50 cc/m2/24 hours at 73°F, to the support member at a second seal so as to enclose the permeable film, wherein the second seal encloses but does not overlap the first seal, 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.

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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 ^iie flange portion.

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

18

26 4 4 4 1

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 substantially 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.

with reference to the accompanying drawings.

24. A method for packaging a Droduct substantially as herein described with reference to the accompanying drawings.

A package for a product substantially as herein described