RECLOSABLE FOOD PACKAGING
The present invention relates to food packaging, and has particular reference to packaging for fresh or perishable foodstuffs such, for example, as meat, fish, poultry, game, meat extracts, preserved, dried or cooked vegetables or fruit, jellies, jams, fruit purees, pates, pies or pieces of meat (e.g. smoked bacon) and the like. The present invention also relates to a method of manufacturing such food packaging.
Many different ways of packaging fresh and/or perishable foodstuffs are known to those skilled in the art. Some types of such packaging are manufactured from composite thermoplastics materials. Yogurt, for example, is typically packaged in cups, bowls or other similar receptacles that are manufactured from sheets of such thermoplastic composite material. Said composite material is usually in the form of a laminate comprising an inner sealing layer and an outer structural layer to give the packaging a degree of rigidity. The inner layer may, for example, comprise PE (polyethylene) which is well known to those skilled in the art as a suitable sealing material, whilst the outer layer may comprise A- PET (amorphous polyester), X-PET (expanded polyester), PP (polypropylene) EPP (expanded polypropylene) or PS (polystyrene) . The open, upper end of the receptacle is tightly sealed after filling with the foodstuff by means of foil, usually aluminium foil. In order to remove the foodstuff from the receptacle, a consumer must first tear off the foil which can then no longer be replaced in such a manner that the receptacle is sealed. Thus, if only part of the foodstuff is removed from the receptacle, the consumer must find other ways of re- sealing the packaging to store the remaining foodstuff in the receptacle for future use.
Other kinds of food packaging known to those skilled in the art for use in packaging fresh and/or perishable foodstuffs comprise a receptacle and a separate, removable closure therefor. In particular, such packaging is often used for packaging jams and other preserves. However, with this type of packaging, the closure may be mislaid or lost. Furthermore, the manufacture of two separate components, namely the receptacle and closure, is time-consuming and costly.
After manufacture, of course, the two components have to be assembled, either by machine or manually, and this adds to the overall manufacturing cost . An object of the present invention is to provide an improved form of food packaging.
Another object of the present invention is to provide a method of manufacturing such food packaging.
In particular, it is an object of the present invention to provide an improved food packaging suitable for packaging fresh and/or perishable foodstuffs of the kind mentioned above.
A specific object of the present invention is to alleviate some or all of the problems mentioned above associated with food packagings that are known to those skilled in the art.
According to one aspect of the present invention therefore there is provided a reclosable food packaging comprising a receptacle and a closure therefor, which receptacle and closure are formed as a single piece from thermoplastics material and are joined to one another by hinge means for allowing movement of the closure relative to the receptacle for repeated opening and closing of the receptacle, and releasable securing means for releasably securing the closure in the closed position. Typically, the receptacle and closure are formed from a sheet of thermoplastics material by shaping techniques known to those skilled in the art. In some embodiments, the sheet may comprise a composite thermoplastics material such, for example, as a laminated sheet. Said composite may comprise a first layer comprising a fluid- tight sealing material that forms an inner lining of the receptacle and a second layer of structural material. In one embodiment, the first layer may comprise polyethylene which is known to those skilled in the art as a suitable sealing material for food packaging. The second layer may comprise A-PET, X-PET, PP, EPP or PS which imparts structural rigidity to the packaging.
Optionally, the laminated sheet may comprise a third layer of an oxygen-impermeable material, preferably ethylene vinyl hydroxide (EVOH) . Said third layer may interpose the first and second layers .
Alternatively, the sheet may comprise a monomaterial such, for example, as PP, which is suitable for use in microwave ovens .
Said closure may be joined to the receptacle by one or more webs of said thermoplastics material, which web or webs may be suitably treated to provide said hinge means. In particular, the web or webs may be perforated or pressed with a pressing a blade device of the kind known to those skilled in the art to form a hinge between the closure and receptacle which can be open and closed repeatably without breaking.
The present invention thus provides food packaging comprising a receptacle and an integrant closure which are manufactured as a single piece which is simpler and cheaper than manufacturing and assembling separate receptacle and closure components. Furthermore, as the closure is joined securely to the receptacle, the possibility of a consumer mislaying or using the closure is eliminated.
Said receptacle may contain a foodstuff in accordance with the present invention, typically a fresh and/or perishable foodstuff.
In a particularly advantageous aspect of the present invention, the foodstuff is sealed in a receptacle by means of a removable film that is adhered to the receptacle. Said film may comprise aluminium foil that is adhered to the receptacle by means known to those skilled in the art. Alternatively, the film may comprise a thermoplastics material such, for example, as PE (polyethylene). In some embodiments, the sealing film may comprise a laminate comprising a first sealing layer and a second oxygen-barrier layer of EVOH. Said sealing layer may comprise polyethylene. Typically, the EVOH layer will be disposed outside the sealing layer when the film is applied to the receptacle.
In some embodiments, the laminate may comprise a third layer disposed outside the EVOH layer, which third layer is formed from a material selected from OPP (oriented polypropylene), OPA (oriented polyamide), PET (polyester) or PA (polyamide) .
Said sealing film may be adhered to the receptacle by any suitable means known to those skilled in the art, for example, by heat-pressing in a wrapping machine or by ultrasonic welding.
In some embodiments, the receptacle will be provided with a rim around the opening of the receptacle. Said sealing film may be adhered to the rim. Preferably, the rim will have a flat upper surface to provide a suitable adherend for the film. Advantageously, said film will comprise at least one portion that is not adhered to the receptacle so as to provide a tear-off tab that can be gripped manually by a consumer for removing the film from the receptacle.
Preferably the closure is adapted to overlay completely the sealing film in the closed position. Typically the closure comprises a crown that is adapted to overlay the opening of the receptacle and a skirt portion that is adapted to overlay the joint between the closure and the receptacle in the closed position.
Preferably, the width of the skirt increases with distance from the hinge means. Typically, the width of the skirt may increase progressively from the hinge means such that the skirt has a wedge-like shape when viewed from "Che side.
Said releasable securing means may be positioned on the widest part of the skirt which opposes the hinge means .
Preferably, the releasable securing means is formed integrally with the receptacle and closure. In some embodiments, the releasable securing means comprises engaging means formed on the closure or receptacle and cooperating means on the receptacle or closure, which engaging means is adapted for releasably engaging the cooperating means for securing the closure in the closed position. Said engaging means may comprise one or more protrusions on the closure adapted to engage with the rim of the receptacle. In some embodiments, a plurality of protrusions may be provided. The elasticity of the thermoplastics material from which the packaging is formed allows repeated operation of the releasable securing means.
In an especially preferred aspect of the present invention, the packaging comprises a body portion that defines a plurality of receptacles and a single closure therefor, which body portion and closure are formed from a single piece of thermoplastics material and are joined to one another by hinge means for allowing movement of the closure relative to the body portion for repeated opening and closing of the packaging, and releasable securing means for releasably securing the closure in the closed position.
Each receptacle may be filled with the same or a different foodstuff. Preferably, the foodstuff in each receptacle is sealed therein by means of a removable film. A single piece of film may be used to seal all of the receptacles. Said single piece of film may be perforated to define a plurality of portions, each of said film portions sealing a respective one of the receptacles, wherein each film portion can be removed separately to allow the receptacles to be opened individually. Of course, the film material may be aluminum foil or a thermoplastics material as described above.
In another aspect of the present invention there is provided a method for manufacturing a reclosable food packaging in accordance with the present invention, which method comprises forming a sheet of thermoplastics material into a receptacle and integrant closure that are connected by a web of said thermoplastics material, and thereafter treating said web to form hinge means for allowing movement of the closure relative to the receptacle for repeated opening and closing of the receptacle, and providing releasable securing means for releasably securing the closure in the closed position.
Typically, said web may be treated using a pressing blade device which punches or perforates said web at regular intervals .
Preferably, the releasable securing means are integral with the receptacle and closure and are formed from the sheet of thermoplastics material at the same time as the receptacle and closure.
In some embodiments, the sheet of thermoplastics material may be formed into a body portion comprising a plurality of receptacles and a single closure therefor.
In some embodiments , the method may further comprise the step of charging the or each receptacle with the same or a different foodstuff, and thereafter sealing the or each receptacle with a sheet of sealing film material of the kind disclosed above. Said sealing film may be adhered to the or each receptacle by means of heat treatment or ultrasonic welding. Said method may further comprise the step of perforating the sealing film to define a plurality of portions wherein each portion seals a respective one of the receptacles, and wherein each portion can be removed separately to allow the receptacles to be opened individually. Following is a description by way of example only with reference to the accompanying drawings of methods of carrying the present invention into effect.
In the drawings : -
Figure 1 is a plan view of a food packaging in accordance with a first embodiment of the present invention, with the lid shown in an open position.
Figure 2 is a side elevation of the food packaging of figure 1 shown upside down.
Figure 3 is a plan view of a food packaging in accordance with the second embodiment of the present invention.
Figure 4 is a plan view of a third embodiment of the present invention.
Figure 5 is a side elevation of the food packaging of figure 4 with the lid shown open.
Figure 6 is an enlarged side view of the food packaging of figures 4 and 5 with the lid shown in a closed position. Figure 7 shows a detail of figure 6.
Figure 8 is a flow diagram for a method of manufacturing food packaging in accordance with the present invention.
With reference to figures 1 and 2, a food packaging 1 in accordance with the present invention comprises a plurality of receptacles 3 and a lid 2. In the embodiment shown, the packaging 1 comprises two adjacent receptacles 3, although more receptacles, for example three or four, may be provided as required. Said receptacles 3 and lid 2 are formed as a single piece from a sheet of composite thermoplastics material. Said thermoplastics material consists of a layer of polyethylene that is laminated to a layer of a structural thermoplastics material selected from A-PET, X-PET, PP, EPP or PS. The receptacles 3 and lid 2 are formed from the sheet such that the polyethylene layer forms an inner lining to the receptacles and lid 2.
Each receptacle 3 comprises a generally flat bottom wall 16 and a plurality of upstanding side walls 17. Said bottom wall 16 is formed with a plurality of ridges 18 for strength. Said side walls 17 are also ribbed at 8 for reinforcement. Each receptacle 3 has an upper end 14 which defines an opening 15 to the interior of the receptacle, which upper end 17 is surrounded by an integrant rim 13. Said rim has a generally flat upper surface 19. As can be seen from figure 1, the rim 13 is generally rectangular in plan view and is connected at one long side 21 to the lid 2 by a thin web 21 of said composite thermoplastics material. Said web 21 is pressed, for example by means of a pressing blade device, along a straight line to form a hinge between the receptacles 3 and the lid 2.
Said lid 2 is generally rectangular in plan view and is shaped to overlay completely the rim 13 of the receptacles 3. Said lid comprises a crown 22 and a circumferential skirt portion 5. Said crown 22 is formed with one or more ridges for strength. Said skirt portion 5 extends from one end of the hinge 4 around the periphery of the lid 2 to the other end of the hinge 4 as shown in figure 1. The skirt portion is of generally uniform depth along the other long side 23 of the lid 2 that opposes the elongate web 21 between the lid 2 and the receptacles 3. Across the two short sides 24 of the lid 2, the depth of the skirt portion 5 increases progressively away from the hinge 4, such that in side view, as shown in figure 2, the skirt portion 5 is wedge- shaped .
The hinge 4 allows the lid 2 to be moved relative to the receptacles 3 between an open position as shown in figures 1 and 2 and a closed position (not shown) in which the lid 2 completely overlays the rim 13 around the receptacles 3. In the closed position, the skirt portion 5 overlays the joint between the lid 2 and the rim 13, and the other long side 23 of the skirt portion 5 is provided with a plurality (in this case three) of protrusions 6 that engage resiliently under the rim 13 on the other corresponding long side 25 of the rim 13 that opposes the web 21. As the lid 2 is moved towards the closed position, the protrusions 6 on the lid 2 engage the upper surface of the rim 13, and the elasticity of the composite thermoplastics material allows the rim and/or protrusions 6 to deform sufficiently to allow the protrusions to snap behind the rim 13 for securing the lid 2 in the closed position. The packaging 1 can be reopened by urging the other long side 23 of the lid 2 away from the other long side 25 of the rim 13. The packaging can thus be opened and closed repeatably.
After filling the receptacles 3, the openings 15 of the receptacles 3 are overlaid by a sealing film 11. Said sealing film 11 comprises a laminated sheet comprising a first layer of PE as a sealing material a second oxygen-impermeable layer of EVOH and a third layer selected from OPP, OPA, PET, PP and PA. The sealing film 11 is applied to the rim 13 such that the third layer is disposed uppermost. Said sealing film 11 is sealed to the rim around the edge of each receptacle 3 by heat pressing or ultrasonic welding. Adjacent each receptacle 3, a portion of the sealing film 11 is left unattached to the rim to provide a tear-off tab 9. Said tab 9 can easily be gripped by a consumer for removing the film from the receptacle 3.
After application of the sealing film 11, said film 11 is perforated between adjacent receptacles 3 as shown at 10, so that the portion of the sealing film 11 that covers each receptacle can be removed separately from the rest of the film to allow each receptacle to be opened individually.
It will be seen that in the closed position, the lid overlays the sealing film 11 to protect the film from damage, for example tearing or puncture. In some embodiments, the packaging 1 may be perforated between adjacent receptacles 3 to allow the receptacles 3 to be detached from one another before opening.
The packaging shown in figure 3 is constructed in similar fashion to the packaging of figures 1 and 2, save that only one receptacle is provided.
Figure 4 shows a food packaging similar to the packaging of figures 1 and 2, except that each receptacle is generally circular in plan view, having only one generally circular upstanding side wall 26. Furthermore, the other long side 23 of the lid 2 is provided with a plurality of substantially uniformly spaced notches 20 that are adapted to engage under the other long side 25 of the rim 13 in the same way as the more elongate protrusions 6 of figures 1 and 2.
The interengagement of the notches 20 with the rim 13 is illustrated in detail in figures 5 to 7. Figure 5 shows the packaging 1 ' ' of figure 4 with the lid in the open position. The other long side 25 of the rim 13 is exaggerated for clarity. In figure 6, the lid 2 is shown in the closed position, with the notches 20 clearly engaged under the rim 13. As can be seen from the enlargement of figure 7, the notches 20 are configured such that the rim 13 is held snugly in a recess 26 defined by the notches 20 and the crown 22 of the lid 2, such that the lid 2 is secured firmly in the closed position. To reopen the packaging 1' ' , a consumer grips the long side 23 of the lid 2 and the receptacles 3 and urges said long side 25 upwardly away from the long side 25 of the rim. The inherent elasticity of the composite thermoplastics material from which the packaging is formed allows the notches and/or rim 13 to deform sufficiently to allow the notches 20 to ride over the rim 13 to release the lid 2.
As shown schematically in figure 8 therefore the packaging in accordance with the present invention can be formed simply and inexpensively by moulding a single sheet of thermoplastics material into the desired shape that defines one or more receptacles and an integrant lid. The or each receptacle 3 is then filled with a foodstuff, and thereafter the foodstuff(s) is sealed in the or each receptacle by means of a sealing film 11 which overlays the receptacle(s) and is adhered thereto by heat pressing. The film 11 is then perforated between the receptacles, so that the film can be removed from each receptacle separately. The web 21 that connects the receptacle(s) 3 to the lid 2 is then pressed using a known pressing device to form a hinge 4.
If desired, the receptacle(s) can be filled under vacuum or in an inert atmosphere to avoid oxygen penetration into the foodstuff (s) . The use of an EVOH layer in the sealing film 11 will assist in preventing oxygen penetrating into the foodstuff(s) during subsequent storage.