NZ232494A - Hermetically sealed package with reclosable adhesive strip - Google Patents

Description

/ 23249 Priority - v'a):..IP.P.2<.

Corr^tr1 Specification Filed: 01 ■ ?• nmw P«tffic«'.}an Dais: «...

P.6. Journal, Ko: A new zealand patents act, ] 953 No.: Date: complete specification "keclosabie package" Jc/We, W R GRACE & CO-qonn, a corporation organised under the laws of the State of Connecticut, USA having a place of business at 1114 Avenue of the Americas, New York, New York 10036, USA hereby declare the invention for which X/ we pray that a patent may be granted to SSS/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- - 1 - (Followed by page 1A) / 232 i Reclosable Package Field of the Invention The present invention relates to reclosable packaging, and more particularly to reclosable packaging for food products wherein the package is hermetically sealed and also includes an adhesive openable/reclosable strip.

Background of the Invention Many products, especially food products, are packaged in flexible or semi-rigid packaging materials made from polymeric films or laminates. In the case of food products such as luncheon meats, frankfurters, and the like, it is often desirable to use a portion of the contents and store the remainder in the refrigerator for later use.

Hermetic sealing of packaging materials for food applications is well known in the art. Because these packages are typically opened by a knife or other implement, they are not easily opened and are not reclosable.

Much effort has been directed towards the production of easy open packages where incompatible sealants or other systems are used to produce a package which can be opened without the use of a knife or other implement. However, such packages often are too easily opened, and the structural integrity and safety of the contained food product is therefore jeopardized. 4/900126.9/SPECFLDR 01/26/90 1ft Itfti- 232494 v • Even in the case of many easy open packages, these packages are often not reclosable and therefore do not provide the possibility of use of a portion of the contained product, and storage and later use of the remainder of the product.

^ It is therefore desirable to provide the combina tion of package integrity and product safety associated with a hermetic seal, and a reclosable feature which allows the end user to store unused portions of the package once opened for later use.

Attempts have been made even in this area to provide such a combination. U. S. Patent No. 4,782,951 (Griesbach et al) discloses a reclosable package having interlocking closure strips positioned outside of a hermetic seal or seal area. The hermetic seal is of the easy open type so as not to destroy the integrity of the package or closure strips on opening.

Such a combination suffers from the requirement of using interlocking closure strips which require either a complex extrusion of the closure strips during production of the package material, or the separate step of applying the strips as discrete components to the packaging material prior to the final packaging operation. Additionally, such closure strips can be relatively expensive to use in these packaging applications.

It is therefore also desirable to provide a reclosable package which includes a hermetic seal, and a means of opening and reclosing the package to preserve unused portions of the contained product, but without the necessity of utilizing relatively expensive interlocking closure strips, or complicating the extrusion process by incorporating the closure strips into the extrusion steps. 4/900126.9/SPECFLDR 01/26/90 2 2324 Summary of the Invention In one aspect of the present invention, a reclosable package comprises a first film; a second film; a product placed on the first film; a hermetic seal located around the periphery of the package, and sealing the first and second films together in the seal area; and an openable and reclosable adhesive strip bonded to and between the first and second films, and located along one side of the package, substantially parallel to and spaced apart from a relevant portion of the hermetic seal.

In another aspect of the present invention, a method for making a reclosable package comprises applying an adhesive strip along one side of a first film; placing a product on the first film; covering the product and first film with a second film; and hermetically sealing the first and second films together around the periphery of the package, the adhesive strip located substantially parallel to and spaced apart from a relevant portion of the hermetic seal, and between the first and second films.

In still another aspect of the present invention, a reclosable package comprises a tubular film; a product inserted into the interior of said tube; a longitudinal hermetic seal; a transverse hermetic seal at either end of the tube; and an openable and reclosable adhesive strip bonded to and between adjoining surfaces of the tubular film, substantially parallel to and spaced apart from the longitudinal hermetic seal.

In yet another aspect of the present invention, a method of making a reclosable package comprises indexing a film downwardly in a vertical form/fill/seal machinc; applying an adhesive strip to the inner surface of the film; forming the film into a tube; longitudinally sealing the tube; inserting the product into the tube; and transversely sealing the tube at both ends to reduce a package having a hermetic 4/900126.9/SPECFLDR 01/26/90 3 232494 longitudinal seal, hermetic transverse seals, and an adhesive strip.

Brief Description of the Drawings Figure 1 is a plan view of a reclosable package in accordance with the present invention.

Figure 2 is a plan view of an alternate embodiment of the inventive package.

Figure 3 is a partially schematic cross-sectional view of the package of Figure 1.

Figure 4 is a partially schematic cross-sectional view of the alternate embodiment of Figure 2.

Figure 5 is a plan view of still another embodiment of the invention.

Figure 6 is a plan view of yet another embodiment of the invention.

Figure 7 is a partially schematic perspective view of a thermoforming system in connection with the present invention.

Figure 8 is a partially schematic perspective view of a vertical form/fill/seal system in connection with the present invention.

Description of the Preferred Embodiments Referring to Figure 1 a package 10 includes a first film 12 (see Figure 3) and a second film 14. Packaging films especially for food applications are well known in the art, and vary according to the desired end use properties includ- 4/900126.9/SPECFLDR 01/26/90 4 2324 ing heat sealability, abuse resistance, shrinkability, optics, and other considerations.

When a suitable film 12 and film 14 are selected, these may be used in various processes such as thermoforming or vertical form/fill/seal operations, in connection with the present invention, to provide a package having a reclosable feature and a hermetic seal. Figure 1 shows a food product 16 packaged within films 12 and 14 and having a hermetic seal 18 around the periphery of the package.

An adhesive strip 20 is located on one side of films 12 and 14 i.e. towards one end of the final package, and in the case of Figure 1 is located between a relevant portion 19 of the hermetic seal 18, and the food product 16.

Upon opening the package, the hermetic seal 18, at relevant portion 19 is preferably a peelable hermetic seal which can be peeled back, and through adhesive strip 20 to gain access to food product 16.

Food product 16 is depicted in Figure 2 in general fashion, but can be for example luncheon meats, frankfurters, and other food products, often in discrete portions, which may be used in part with the remainder resealed by closing the package back along adhesive strip 20. In this way, the advantages of both a reclosable seal 20 and a hermetic seal 19 are obtained.

Figure 2 shows an alternate embodiment of the invention in which the adhesive strip 20 is located outside of the hermetic seal 18 and its relevant portion 19. Put differently, the relevant portion 19 of hermetic seal 18 of Figure 2 is located between the adhesive strip 20 and the food product 16.

The adhesive strip 20 may be applied by various means and in various ways to either the first film 12 or 4/900126.9/SPECFLDR 01/26/90 232494 second film 14, or both. Typically it will be applied in a substantially linear way along a relatively narrow portion of one side of the film 12 or 14, or both. Also typically, the adhesive strip 20 will be substantially parallel to a relevant portion 19 of the hermetic seal 18, i.e. that portion of the hermetic seal 18 closest to the adhesive strip 20.

The adhesive used in the adhesive strip 20 is preferably a green, i.e. uncured hot melt adhesive. Such adhe-sives are well known in the art. The adhesive is preferably applied by a nozzle or like dispensing means to the film during the packaging process. In this way, roll stock used in the packaging process will not be complicated by the presence of the adhesive before the packaging steps are initiated. However r the adhesive may also be applied as a discrete strip of material, for example a thermoplastic polymeric material, to which a hot melt or similar material has been applied.

Figures 3 and 4 show a cross sectional view of the packages of Figures 1 and 2, and the relationships among the various components of the package.

The films 12 and 14 of Figures 3 and 4 are depicted as monolayer films, and preferably comprise a heat sealable material which can be heat sealed at seal areas 18 to produce the finished package. Other types of films having for example radiation frequency sealability may also be used. Also, multilayer films are included within the scope of this invention.

Referring to Figures 5 and 6, alternate embodiments of the invention include the use of multiple adhesive strips 20a and 20b. Using this feature of the invention, adhesives with preferential resistance to certain types of contaminants, such as oil and water, may be used with effectiveness. Adhesive strip 20a of Figures 5 and 6 represents an adhesive with a preferential resistance to water. Adhesive 4/900126.9/SPECFLDR 01/26/90 6 232 4 94 strip 20b of Figures 5 and 6 represents an adhesive with a preferential resistance to oil. Of course, these may be reversed, or additional adhesive strips 20 may be used.

Referring to Figure 7, a thermoforming system is shown in a fragmentary partially schematic perspective view. The system 30 includes a thermoforming machine 32 and cavities 34 formed within a film 36 fed from a roll 38. As film 36 proceeds from right to left, cavities 34 are formed in the film. A source 40 of a hot melt uncured adhesive delivers the adhesive to nozzles 42 which apply the adhesive in a strip pattern 44 along the film 36 as it is advanced. A food product may then be placed in the formed cavities in film 36 and covered with a second film to produce a package like that depicted in Figures 3 and 4, but with a formed cavity in the lower film.

Figure 8 shows the use of the present invention in a vertical form/fill/seal system 50 in which film 52 is indexed around a mandrel 54 and a food product is introduced through a tube 56 in a sequence well known in the art. A source of hot melt adhesive 58 introduces the adhesive to the interior of the tubular film as it is being formed. The tubular film is longitudinally sealed at 60 and transversely sealed at 62 to produce a package having a longitudinal hermetic seal, two transverse hermetic seals (top and bottom of the finished package) and an adhesive strip located substantially parallel to and spaced apart from the longitudinal seal 60.

While the present invention has been described in terms of preferred embodiments, those skilled in the art will understand that modifications may be made after review of the specification and drawings. Such modifications are deemed to be within the scope of the claims that follow. 4/900126.9/SPECFLDR 01/26/90 7

Claims (25)

232494 WHAT J&WE. CLAIM IS:

1. A reclosable package comprising: a) a first film; b) a second film; c) a product placed on the first film; d) a hermetic seal located around the periphery of the package, and sealing the first and second films together in the seal area; and e) an openable and reclosable adhesive strip bonded to and between the first and second films, and located along one side of the package, substantially parallel to and spaced apart from a relevant portion of the hermetic seal.

2. The reclosable package of claim 1 wherein the first film is a thermof ormable film, and the product is placed in a product cavity formed in said film.

3. The reclosable package of claim 1 wherein the openable and reclosable adhesive strip is located between the relevant portion of the hermetic seal and the product.

4. The reclosable package of claim 1 wherein the relevant portion of the hermetic seal is located between the adhesive strip and the product.

5. The reclosable package of claim 1 wherein the hermetic seal is a peelable seal. 4/900126.9/SPECFLDR 01/26/90 8

6. The reclosable package of claim 5 wherein rhe hermetic seal has an opening force of substantially between 1/2 pound and 6 pounds.

7. The reclosable package of claim 5 wherein the hermetic seal has an opening force of no greater than 6 pounds.

8. The reclosable package of claim 5 wherein the hermetic seal has an opening force of no less than 1/2 pounds.

9. The reclosable package of claim 1 wherein the product is a food product.

10. The reclosable package of claim 1 wherein the first and second films each comprise a polymeric heat seal-able layer.

11. The reclosable package of claim 1 wherein two or more openable and reclosable adhesive strips are bonded to and between the first and second films, and located along one side of the package, substantially parallel to and spaced apart from each other and the hermetic seal.

12. The reclosable package of claim 11 wherein at least one of the adhesive strips resists fat contamination.

13. The reclosable package of claim 12 wherein at least one of the adhesive strips resists water contamination.

14. A method for making a reclosable package comprising: a) applying an adhesive strip along one side of a first film; ~ b) placing a product on the first film; 4/900126.9/SPECFLDR 01/26/90 9 .. 9 f 1 "v , % '^ovI99M 23248 c) covering the product and first film with a second film; and d) hermetically sealing the first and second films together around the periphery of the package, the adhesive strip located substantially parallel to and spaced apart from a relevant portion of the hermetic seal, and between the first and second films.

15. The method of claim 14 further comprising, before step (a), corona treating the first film on the film surface to which the adhesive strip of step (a) is applied.

16. The method of claim 14 further comprising thermoforming the first film to create a product cavity, and placing the product in the cavity, prior to step (C).

17. The method of claim 14 wherein the adhesive strip is applied by injecting the adhesive through a nozzle onto the film surface.

18. The method of claim 14 wherein the adhesive strip is located between the relevant portion of the hermetic seal and the product.

19. The method of claim 14 wherein the relevant portion of the hermetic seal is located between the adhesive strip and the product.

20. The method of claim 14 wherein two or more adhesive strips are applied along one side of the first film, substantially parallel to and spaced apart from each other.

21. A reclosable package comprising: a) a tubular film; 4/900126.9/SPECFLDR 01/26/90 10 ?524?4 i

22. prising: b) a product inserted into the interior of said tube; c) a longitudinal hermetic seal; d) a transverse hermetic seal at each end of the tube; and e) an openable and reclosable adhesive strip bonded to and between adjoining surfaces of the tubular film, substantially parallel to and spaced apart from the longitudinal hermetic seal. A method for making a reclosable package com- a) indexing a film downwardly in a vertical form/fill/seal machine; b) applying an adhesive strip to the inner surface of the film; c) forming the film into a tube; d) longitudinally sealing the tube; e) inserting product into the tube; and f) transversely sealing the tube at both ends to produce a package having a hermetic longitudinal seal, hermetic transverse seals, and an openable and reclosable adhesive strip bonded to and between adjoining surfaces of the tubular film. //' \ v o 4/900126.9/SPECFLDR 01/26/90 11 r _ ■■ ■ ■ v* -t;232494;

23. A package as claimed in any one of claims 1 to 13 and 21 substantially as hereinbefore described with reference to any of the accompanying drawings.;

24. A method as claimed in any one of claims 14 to 20 and 22 when performed substantially as hereinbefore described with reference to any of the accompanying drawings.;

25. A package made by a method as claimed in any one of claims 14 to 20, 22 and 24 substantially as hereinbefore described.;BATED THIS 19q0;A. J. PARK * SON per agents for the applicants -J 12-