AU751828B2 - Reclosable packaging system and relevant manufacture process - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): SAFTA S.P.A.

Invention Title: RECLOSABLE PACKAGING SYSTEM AND RELEVANT MANUFACTURE PROCESS The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 RECLOSABLE PACKAGING SYSTEM AND MANUFACTURING PROCESS The present invention relates generally to reclosable packaging systems and relates particularly, though not exclusively, to a packaging system including a container body of commercial products in doses superior to the monodose, and a composite sheet to form a lid easy to open and repeatedly reclose.

.9 10 A system of this kind is described in the Applicant's 9 European Patent No. 0661154 in which however several structural and technological aspects are not faced. For 9.

.instance the features of tamper-evident and of easily opened packaging are mentioned but no optimal embodiments 9.

thereof are described. Moreover, in the development of its packaging systems the Applicant had to protect the contents of the tray against possible contamination by the components of the reclosable cover forming laminate.

00 °1Q @9 It is understood that an undesirable interaction between the contents and the lid components can occur in the sense 99 that some particular contents may develop aggressive substances which damage or at least spoil the laminate performance which in particular can weaken the inter-layer 25 adhesion acting on the integrity of the press-sensitive adhesive. Further, the packaging is to be designed to have a specific means for the ad hoc handling of the container and in particular to be able to close and separate the outer upper layer from the internal layer with relative ease. It is also necessary to be able to handle in the best way the packaging both in the opening phase as in the phase to extract the contained product and in the last but not least phase of reclosure or re-sealing of the container.

It is convenient to premise that packaging technology is passing progressively from the phase in which the sole \\GHSYDNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 3 purpose of the packaging is the protection and conservation of the packed product to the phase in which the packaging becomes a means utilized by the transformation industry to communicate to the final user the characteristic features of the packed product. As a consequence of this always more important role of the packaging the relevant industry had to and is succeeding to create more and more innovations by putting on the market continuous improvements in the packaging with the purpose of increasing the level of the service offered to the consumer.

In line with what has previously happened with rigid (unflexible) packaging (glass, metal, plastics), the field of flexible packaging has also demanded and provided containers which can be opened and reclosed with relative ease. Thus also with flexible packaging the trend has been e from mono-dose into pluri-dose packaging, whilst maintaining the sealing and hermetic closure characteristics.

The reasons for the evolution are to improve: the services to the consumer by offering the possibility of consuming packaged product several times; the ratio of packaging cost to packed product thanks to the possibility of increasing the packed product eo quantity; V00. the environmental impact of the packaging as again a consequence of the changed ratio of the packaging to the contained product.

o According to the present invention there is provided a resealable packaging system comprising flexible composite multilayer foils forming a lid which may be opened and reclosed repeatedly, said multilayer foils comprising: an outer multilayer film including: a mechanically resistant layer adapted to receive printed data; a gas barrier layer; and J:\Speci\300 399\300 349\32463.doc 24/06/02

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r- C 4 a layer of pressure-sensitive adhesive; a second lower inner film having a cut line giving access to a container closed by said multilayer film said lower inner film comprising: a mechanically resistant layer; a thermosealing layer; and a pressure-sensitive adhesive layer; said packaging system having; an open border; an opening stopping device; a protecting layer for guarding against possible undesirable effects of a product in the package; a tamper evident device; and an easy open lifting border.

The various aspects and advantages of the invention will better appear from the description of the preferred o embodiments shown in the accompanying drawings in which: Figure 1 is a partially cross-sectioned view of a 20 basic packaging similar to that disclosed in European Patent No 0661154 but comprising some important characteristics according to one embodiment of the present invention; Figure 2 is a top view of the cross-sectioned package OF Figure 1 showing important features of the lid; Figure 3 is a cross-section view similar to Figure 1 but with a closed lid; Figure 4 is a perspective view of a package with a S•lid partially opened; 'Figures 5a, 5b and 5c represent some of the possible compositions of the laminate of the lid; Figures 5d and 5e represent some of the possible compositions of the laminate of the container (tray); and Figure 6 is a block diagram of the possible embodiments of the process to manufacture a finished package according to one embodiment of the invention.

In Figure 1 the multilayer laminate of the reclosure lid CO of the container (for example a tray) VA of the consumable product (not shown) to be protected is indicated by the \\GHSYDNT2\users\Speci\300 399\300 349\32463.doc 9/01/01 5 reference 1. Said laminate 1 comprises an external top layer 2 and preferably being a multilayer, see figures 5c) which has the function to support the "repositionable" adhesive 4 as well as personalized printing on the package.

As can be better seen from Figure 5c, the layer 2 can also and preferably comprises a gas barrier layer Layer 3 indicates the laminate inner layer which can consist of one 10 or more thermoplastic films such as those indicated with 3' Q* and 3" in the Figures 5a, 5b and 0 'e g Said layer 3 is die-cut (die-cutting 6-6 in Figures 1-4).

According to an advantageous feature of this embodiment of the invention laminate 1 can, preferably, comprise a protective film 5, as indicated in the Figures 5a and The main characteristics of this system as applied to the packaging of containers like trays, and to the relevant lids are outlined below.

A lid multilayer laminate 1 with the lower die-cut layer 3 being constructed substantially in accordance with Patent EP No 661154. The die-cuttings of this embodiment of the invention have form and size suited to the type of tray to 25 be sealed and to the packaged products, and serve to create: A particular and new opening edge 7 which allows an easy grip of the laminate during package opening and reclosing phases. It is obtained through the diecutting 6 of the lower layer of the lid laminate and repositioning of the die-cutting in correspondence with the head welding.

An access mouth which conventionally allows the access and extraction of the packed product. It is obtained through the shaped die-cutting 6 (having the desired form and size) of the lower layer of the lid laminate. Generally the shape size and position of the \\GHSYDNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 6 access mouth are proportioned to the packed product type and to the extraction exigencies.

An additional new device or opening stop 10, which is designed to prevent separation of the upper layer from the lower layer of the laminate when the lid is peeled open. This is obtained by shaping the die-cut end 6 so that it corresponds to the access mouth 9 (see for example Figure 4).

A protective film 5 which is placed on the inner part 10 of the multilayer laminate lower layer. It generally is relatively thin, less than 40 microns, and preferably from 10 to 30 microns, and is capable of breaking in 0* 1' 0. correspondence with the die-cutting outline 6.

Typically and advantageously, the main purpose of the films is to protect the die-cut zone against possible attacks from the packed product and to avoid the possible migration of undesired substances towards the e -package interior.

a.

The container, for example in form of a shaped tray, is conventionally made of plastic material. It is thermoformed on FFS (form-fill-seal) packaging lines or is preformed. The container of this embodiment of the invention is typically characterized by: 25 Grip edge 8 which is obtained by shaping the tray in

A

such a way to allow easy gripping of the tray during opening and reclosing of the lid 1.

Reclosure for several times is obtained through the overlapping and successive light pressure of the upper layer 2-4 on the lower layer 3 adhered to the tray. The gripping action of the press-sensitive adhesive 4 placed between the two layers 2-3 realises a perfect reclosure of the package.

The tamper evident device which clearly indicates any possible tampering of the package is positioned in correspondence with the lifting border 7 and is obtained by means of small thermo-weldings 12 (see Figures 1, 2, \\GHSYDNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 7 4) carried out at the same time of the sealing weldings 13. The thermo-weldings 12 have a generally circular form with a diameter of 3-5 mm and their number varies according to the tray size. The tamper evident is thus no longer obtained with the aid of adhesive points but with the aid of the small thermo-weldings 12.

Another characteristics of the system includes easy employment during the preparation phase of the finished 10 packages by the user of the laminates (generally of the food industry).

Even if a laminate according to this embodiment of the 1P 0 invention comprises additional functional features, it is still possible to obtain an advantageously complete insertion within said multilayer of the various above mentioned devices (access mouth 9, opening stop 10 etc.) in such a manner that new reels of this laminate 1 can be completely similar to the conventional laminate reels.

No addition of working parts and/or substantial 0 modification of the conventionally utilized packaging lines is necessary.

S

No particular regulation or control of the machinery •conditions (welding temperature, packaging speed) 25 normally utilized for the conventional laminate packaging is necessary.

Composition of the multilayer laminate 1.

The outer layer 2 (having the function of support of the repositionable adhesive 4 and of any possible printing) is generally constituted of one or more films of plastics, paper or metal, with characteristics of protection, barrier, printing and appearance so to be suited and adapted to the type of package and/or packed product as for instance shown in detail in the Figures 5a, 5b and \\GHSYfNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 8 The inner layer 3 of laminate 1 having the function of a thermosealable film, is submitted to die-cutting operations 6 to obtain: an invitation to the easy-open through a primer of the separation between the support upper layer 2 and the inner layer 3; product access mouth 9 having shape and size adequate to said packed product; opening block 10 positioned at the end of the S 10 access mouth 9.

eO The inner layer 3 is usually constructed of a plastic film *o or a generally plastic film combination as shown in Figures 5a, 5b and *s The intermediate layer 4 consists of repositionable adhesive AR having a particular capacity to adhere to the support outer layer 2 and the inner layer 3. This presssensitive adhesive, preferably of an acrylic nature, is so 20 formulated that its gripping capacity remains unalterated even after repeated detachments of the superior layer 2 from the inferior layer 3. During the opening phase the Soadhesive layer 4 remains positioned on the upper layer 2 while detaching a portion of the lower layer 3.

0 As anticipated and according to a feature of one embodiment of the invention, the laminate comprises also a protection thin film 5, which must in particular cover the die-cut zones 6, and has properties of thermosealability compatible with the thermosealant layer of the tray 14. Preferably the film is constructed of polyolefin resins and has a thickness not greater than 40 microns and preferably from to 30 microns.

Bottom multilayer laminate 11 The container in particular the tray now provided with a \\GHSYlNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 9 lifting edge can be preformed or be thermoformed on the FFS packaging lines normally used for the tray sealing. It consists of an inner layer having thermosealing functions 14, compatible with thermosealant films 3-5 (also protective) of the above described lid multilayer laminate 1. It is formed of polyolefin resins, for instance PE or PP. Internally to said film 14 a barrier layer can be inserted (see Figure 5c) if it is necessary for the packed product conservation. Generally it is composed of resins 10 EVOH, PVDC, PAN etc. and is applied with the aid of lamination or coextrusion technologies. There is finally an outer thermoformable layer 15 which shows particular characteristics of rigidity, thermoformability and protection, suited to the type of the product to be packed 15 and to the type of package to be manufactured.

Conventionally layer 15 can be obtained with the aid of the lamination or coextrusion technologies and is generally formed of sheets of PET, PVC, PP, PS, OPS, EPP (expanded polypropylene) of variable thickness preferably from a 20 minimum of 150 to a maximum of 800 microns.

0 e Functional features *00 The use by the final consumer of the package according to 25 this embodiment of the invention obviously takes place starting from the operations of initial opening-extraction Sof the packed product followed by reclosure and successive reopening etc.

In detail the operations take place in the following order.

The package easy-opening is carried out by catching with one hand H (Figure 4) the opening edge 7 and with the other hand (not shown) the catching edge of the tray 8. The opening border is pulled upwards so to start the separation (detachment) of the upper layer 2-4 from the lower layer 3 of the lid laminate 1. The layer separation causes the breaking of the small weldings 12 which have the function \\GHSYDNT l\users\Speci\300 399\300 349\32463.doc 20/11/98 of tamper evident element and which according to this embodiment of the invention have proved to be particularly advantageous and innovative. By continuing the operation the access mouth 9 opens and this opening continues until the meeting with the (also innovative and additional) opening stop device 10. Moreover the layer separation causes the breaking of the protective film 5 according to this example of the invention, in correspondence with the die-cutting outline 6. Once the package is opened, the S 10 packed product can be taken out through the access opening 9, which has been uncovered during the partial detachment 0000 s.e: of the support layer 2-4 from the die-cut inner layer 3.

0000 000 The package hermetic reclosure takes place with the repositioning of the upper inner layer 3 caused by a light 0oo 15 pressure capable of adhering these two layers through the repositionable adhesive 4.

The repeatability of the above mentioned operations permit access several times to the product contained in the 20 package till its complete consumption. The characteristics of the package according to this embodiment of the invention are such to allow its use even after full consumption of the packed product.

25 Examples of a detailed structure of the lid multilayer laminate 1 in its complete and relatively complex form are shown in the Figures 5a, 5b, 5c in which the laminate main components are indicated with the basic numeral references already used in the preceding Figures.

Figure 5c depicts a most complete and complex embodiments of the outer layer 2 which is composed of: an outer support film which is thermoresistant and printable, preferably in PET, OPA, OPP, paper etc.; a printing ink of various colours (from one to nine) preferably of vinyl-or nitrocellulose base: a two components polyurethanic adhesive AP; a barrier film \\GHSYDNT1\users\peci\300 399\300 349\32463.doc 20/11/98 11 for the content maximal protection for example consisting of EVOH, PVDC, aluminium, or coated with metal, oxides, PVDC, etc; a two-components polyurethane adhesive AP; a support film for the repositionable adhesive 4 having a composition similar or different from that of the outer layer. The intermediate layer 4 is constructed of the repositionable adhesive AR having the function to keep united the layers 2 and 3 and to allow the package repeated reclosures; said adhesive AR according to this S. 10 example of the invention is preferably of an acrylic base.

.The inner layer 3 comprises a support film to impart stiffness having a composition similar to that of 0. films and a two component PU adhesive; a 0 15 sealing film compatible with layer 5 and bottom 14, preferably of polyolefinic nature (for example PE, EVA, etc.). The protecting layer 5 consists of a polyolefinic film (for example PE, EVA, EAA etc.) of thin thickness (below 40 microns) and has the function to protect the die- 20 cut zone and be compatible with and 14.

e 0 S: In Figure 6 there is shown a block-diagram of a complete, very flexible and thus advantageous process comprising the main steps to obtain the finish package according to this 25 example of the invention. The manufacture of the complex laminate 1 of the package lid 1 (indicated also as CO) takes palce through a series of operations articulated as follows: the support film 2' is printed and coupled (on line with the printing or in a successive-phase) with the barrier film 2" (if present) and/or with the support film or with the combination of the two films 2" i.e.

the two layer laminate A, in the scheme direction or directly with the combination of the two-layer laminate A and B, i.e. the laminate C, in the direction the sealing film is coupled with the support film 3' (if present) to form the two-layer laminate B; \\GHSYNT1\users\Speci\300 399\300 349\32463.doc 20/11/98 12 said laminates A and B are bonded to each other with the aid of the special repositionable adhesive 4, to form the laminate C already comprising the support film 2', if operating in the direction or to be coupled with said 2' in a successive step, if operating in direction laminate C is taken to the partial die-cutting phase consisting in the incision or cut) of the sole layer 3 i.e. the laminate B, in the considered zones and S. 10 forms; the protection film 5 is finally added to C by extrusion-coating or lamination to protect the die-cut zone of B and to act as further sealing layer in addition to film 3"' With this phase the lid structure is completed which has the main function to seal the package and to render easy and safe the opening and reclosing operations.

20 The manufacture of the package bottom container 11, generally a tray, takes place through various phases, some of which are carried out on (or off) line with the filling o Sand final sealing. Synthetizing the main phases are: the sealing film 14, compatible with films 3" and 25 5 of lid 1 is coupled with the barrier film, if present, through lamination or coextrusion, and contemporaneously (or successively) is coupled or coextruded with support film the so prepared bottom laminate 11 is taken to the forming phase carried out separately or (more frequently) in line with the packaging, i.e. together with the product loading and lid welding (or sealing) by means of a thermo-forming machine normally utilized for the preparation of packages.

The finished package is then sent for distribution to be destined to the final use of the consumers. Obviously some \\GHSYDNT\users\Speci\300 399\300 349\32463.doc 20/11/98 13 coupling operations carried out for the bottom and the lid with the aid of polyurethane adhesives, can be accomplished by the coextrusion technology.

The embodiments of the invention are described for clarity with reference to the (preferred and not limitative) embodiments shown in the accompanying drawings and are susceptible of all the variations, substitutions, modifications, etc. which are in the reach of the average 10 skilled person and which fall therefore in the spirit and scope of the present invention.

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Claims (16)

1. A resealable packaging system comprising flexible composite multilayer foils forming a lid which may be opened and reclosed repeatedly, said multilayer foils comprising: an outer multilayer film including: a mechanically resistant layer adapted to receive printed data; a gas barrier layer; and a layer of pressure-sensitive adhesive; a second lower inner film having a cut line giving access to a container closed by said multilayer film said lower inner film comprising: a mechanically resistant layer; a thermosealing layer; and a pressure-sensitive adhesive layer; said packaging system having; an open border; 20 an opening stopping device; a protecting layer for guarding against possible undesirable effects of a product in the package; a tamper evident device; and an easy open lifting border.

2. The system according to claim 1, wherein the stopping 'device is formed by shaping an end of the cut line as an access mouth.

3. The system according to claim 1, wherein the protecting layer is on the inside surface of the lid and facing a content of the package, and the protecting layer has a thickness of not over 40 microns whereby the protecting layer is breakable in correspondence with the cut line. I, J:\Speci\300 399\300 349\32463.doc 24/06/02 ,h c 15

4. The system according to claim 1, further comprising tamper evident means comprising small thermo-weldings formed simultaneously with a sealing welding between the lid and a container body. The system according to claim 1 further comprising a lifting border adjacent a tray shaping edge.

6. The system according to claim 1, wherein the opening cut line is a die-cut in the lower layer of the lid and is positioned in correspondence with a package opening.

7. The system according to claim 6 wherein the lid is easy to open in response to a separation between a 15 pressure-sensitive adhesive layer and the die-cut layer.

8. A flexible composite foil including a multilayer film being adapted as an opening and reclosing means for a "'"container of products to be consumed in successive doses, 20 said composite foil comprising at least: i) an outer multilayer film including a mechanically resistant layer being adapted to serve as a printing support, and a press-sensitive adhesive support; ii) an inner film having an incision or die-cut defining 25 the configuration of a container access mouth and an opening end comprising a mechanically resistant layer; and •T iii) a press-sensitive adhesive layer disposed between the outer and the inner films, the flexible composite foil being characterized in that it comprises an opening border and a protective layer for protection against possible aggressive effects of packaged contents.

9. The flexible composite foil according to claim 8 wherein the opening border is a die-cut of the inner film, positioned in correspondence with a head welding of the "/-\container. \\GHSYDNT2\users\Speci\300 399\300 349\32463.doc 9/01/01 16 The flexible composite foil according to claim 8 wherein the protective layer is on the inferior inner portion of the multilayer film facing the products to be consumed, and has a thickness below 40 microns to be breakable in correspondence with the incision or die-cut.

11. The flexible composite foil according to claim 8 wherein easy opening is effected by separation between the press-sensitive adhesive layer and the inner film.

12. The flexible composite coil of claim 8 wherein the outer multilayer film also comprises a gas barrier layer.

13. The flexible composite foil according to claim 8 wherein the inner film also comprises a thermosealing layer.

14. The flexible composite foil according to claim 8 20 further comprising an easy-open lifting border. The flexible composite foil according to claim 14 wherein the lifting border is defined by a tray shaping of the container.

16. The flexible composite foil according to claim 8 further comprising an opening stopping device together with a tamper-evident device.

17. The flexible composite foil according to claim 16 wherein the tamper evident device includes small thermo- weldings carried out at the same time of the sealing welding between the multilayer film and the container.

18. The flexible composite foil according to claim 16 wherein the stopping device is obtained by shaping the die- cutting of the inner film as the access mouth. \\GHSYDNT2\uers\Speci\300 399\300 349\32463.doc 9/01/01 ,LF -il 17

19. A flexible composite foil substantially as herein described and illustrated in the accompanying drawings. Dated this loth day of January 2001 SAFTA S.P.A. By their Patent Attorneys GRIFFITH HACK 00 0 .0 00* <1 J:\Speci\300 399\300 349\32463 .doc 24/06/02