EP0701955B1 - Packaging for long-life shelf food - Google Patents

Abstract

The container consists of an outer member designed to receive a moisture absorbent pad, and a liner forming a false bottom for the container, which is hermetically sealed. The liner has one set of holes in its base and a second group between the liner and outer member to provide for gas exchange. The outer element has projections on its base to form gas exchange channels and other to support and/or fix the position of the liner. The outer member and the liner are made from polypropylene, welded together with the absorbent pad between.

Description

The present invention relates to a packaging for long-term storage and preservation intended for fresh products tending to exude a liquid capable of significantly reducing their period of consumption.

This type of packaging is intended to preserve products, in particular seafood or meat, for a period of up to twenty days, and is used in an industrial type distribution process for products considered fresh. In other words, it is a packaging used by manufacturers, upstream of the consumer sales circuit, to ensure the conservation during the succession of the various links in the distribution chain.

• conserver le produit dans une atmosphère spécifique lui assurant une durée de vie de longueur maximale, et
• compenser les émanations issues du produit au cours de la période de conservation, et qui sont susceptibles d'altérer ladite atmosphère originelle.

The product is sealed in a sealed volume, in which it is kept consumable as long as possible. Two problems arise:

• store the product in a specific atmosphere ensuring a maximum shelf life, and
• compensate for the fumes from the product during the storage period, which are likely to alter the original atmosphere.

The first is resolved by introducing a gas into the sealed volume after having evacuated therein, said gas mainly having the function of ensuring preservation.

The compensation of the emanations is then carried out by a chemical inhibitor, which must not be in contact with the food, and is hydrosensor so as to act directly on the exudates of the products to be preserved. A good solution consists in using a buffer located between the bottom and a false bottom on which the said product rests, the assembly constituting a packaging tray known per se. This buffer also contains a water-reactive agent capable of modifying the atmosphere according to the fumes of the products, by ventilation effect.

• de mettre et de maintenir les exsudats au contact du tampon, de manière à anéantir leurs effets indésirables, et
• de renouveler l'ambiance gazeuse initiale au fur et à mesure que le temps s'écoule, de manière que les émanations du produit ne la vicient pas, ce qui aurait pour effet de diminuer la durée de vie du produit.

The problem is that the chemical reaction, to perform its function of modifying the atmosphere, requires a gas circulation in the volume of said tray. We must therefore design a structure allowing:

• to bring and maintain the exudates in contact with the tampon, so as to annihilate their undesirable effects, and
• to renew the initial gaseous atmosphere as time passes, so that the fumes of the product do not vitiate it, which would have the effect of reducing the life of the product.

The original structure of the packaging of the invention aims to respond to the problems posed above, by proposing a container type of external container, intermediate buffer and false bottom fitted into the container, with a gas circulation device. internal or, according to another terminology, a ventilation device.

To this end, the invention is provided with a false bottom which comprises a first group of orifices allowing the exuded liquid to be brought into contact with the tampon, and a second group of orifices situated between the useful volume of capacity. of the packaging and a volume defined between the external container and the false bottom and / or the parts of the buffer not in contact with the exudate, so as to establish gas exchanges between the two volumes mentioned.

In addition, the respective shapes of the false bottom and the buffer are provided so as to prevent any contact between the product to be preserved and said hydrosensor buffer.

However, packages are already known which have a ventilation system produced using orifices arranged in several places.

Thus, PCT patent WO 93/06 026 in the name of SEALED AIR CORP. relates to a packaging container for food products which is recyclable and provided with a reservoir making it possible both to receive the liquid exuded by the product and to keep it in said reservoir.

The fundamental characteristic of the subject of the patent is the existence of a central orifice, placed in the lowest part of the false bottom supporting the product, so as to operate the best possible collection of the exuded liquids. The basic configuration has only one central opening at the bottom. However, modified configurations also include lateral orifices, extended by conduits whose free end is located near the bottom. They make it possible in particular to improve the collecting capacities of the product when it is in a vertical or inclined position.

The document also mentions the existence of holes located in the upper part, not connected to conduits such as those which have been mentioned, and which are intended to improve the air / liquid exchanges between the lower volume and the upper part. There is therefore the possibility of a gas circuit, the document of which however does not specifically mention the mode of operation, nor the utility.

According to some of the configurations described, an absorbent pad can also be placed between the bottom and the false bottom, making it possible to absorb the liquids possibly exuded by the product to be packaged.

The existence of regeneration circuits, however, poses the problem of their delimitation, so that the gas flows can be guided from one volume to another. However, there is no solution to this problem in the aforementioned document, which is content in fact to note that the peripheral orifices can be used for the purpose of improving gas exchanges.

The invention which is the subject of the present application responds to this problem, making it possible to maintain gas flow channels whatever the state of the absorbent pad, that is to say even if said pad increases its volume following an absorption. a large amount of liquid.

To this end, the outer container has reliefs intended to establish a gas circulation between the pad and its bottom. These reliefs in fact provide passage zones towards the orifices of the second group. They are in fact canal conduits arranged between flat raised zones supporting the tampon, said conduits intersecting and opening into a peripheral zone of the bottom which communicates with said orifices of the second group.

The configuration is therefore schematically presented as follows: one of the faces of the tampon receives the exudates which pass through the orifices of the first group, that is to say those which are formed in the flat part of the false bottom. The other side, on the other hand, is indirectly oriented towards the orifices of the second group, as well as the lateral sides. This second face rests on the raised areas and gives on the channels of the bottom which intersect, allowing the circulation of the gaseous fluid.

The channels open into a peripheral zone at the bottom of the container, of the same level and located near the orifices of the second group, which are generally located on the part of the false bottom opposite this peripheral zone.

In other words, the exudates, when they cross the false bottom, are absorbed by the buffer which performs its chemical function of neutralization and regeneration. The fumes from the product are therefore inhibited by the buffer which also regenerates the atmosphere, with the help of a gas circulation allowed by the two groups of orifices which in fact create a closed ventilation circuit inside packaging. The only obstacle to the gaseous fluid is constituted by the buffer, one of the faces of which is directed towards one of the groups of orifices, while the other face is rather oriented towards the other group of orifices. However, the nature of the material used to produce said buffer causes the liquid to stop, which cannot cross the obstacle, and simple resistance in the gaseous fluid ventilation loop.

On leaving the buffer, that is to say in the lower part, at the level of the channels formed in the bottom of the container, the air or more generally the regenerated gas can be "reinjected" into the useful volume containing the product, by through the orifices of the second group. Further on, in the gas circulation circuit, at the level of the absorption zones of the exudates by the buffer, the gas is in contact with the said exudates, after having been the product to be preserved proper. It is therefore "vitiated" and requires the regenerative treatment carried out by the tampon.

According to the invention, the outer container also has reliefs on the bottom intended to support the false bottom, or even to fix it. These reliefs, even if they are arranged over a large part of the length or width of the container, should not prevent the circulation of the gaseous fluid. In particular, they give access to the peripheral zone on which the orifices of the second group give.

The tampon may also include orifices, preferably located opposite the orifices of the first group, and forming small exudate reservoirs while the liquid is being absorbed by the tampon. Since the channels at the bottom of the container have the essential function of circulating a gaseous fluid, it is clear that they cannot be opposite the holes in the tampon, so as not to be filled with exudate. The very function of the buffer would no longer be ensured, since we would then be left with gaseous fluid in contact with the exudate on either side of the regenerating buffer.

To improve the efficiency of the exudate "reservoirs", the shape of the orifices in the first group of the false bottom is chosen so that the liquid is trapped when it falls into the holes in the tampon. Thus, the walls of these orifices are funnel-shaped protruding from the false bottom so that the narrow necks of said funnels are introduced into the holes in the tampon.

These walls protruding into the holes of the tampon act in the manner of non-return baffles to block the liquid in the volume thus created between the funnel and the walls of the holes of the tampon, so that if the packaging is tilted or even turned upside down , the liquid not yet absorbed remains in said volumes.

The ends of said funnels are moreover preferably conical, in order to further reinforce the trapping effect of the exudates.

The type of packaging applied to foods that need long shelf life can take many forms, but the need for sealing often involves a fairly deep container. In this case, the orifices of the second group are preferably located in the part of the false bottom having an appearance substantially parallel to the peripheral walls of the external container, and near the zone for fixing said false bottom to the container.

In other words, when the edges of the container rise appreciably, a false bottom is provided, the general appearance of which not only follows the shape of the bottom, but also that of the walls. This allows the designer to introduce the orifices of the second group in the upper part, near the peripheral edges and the sealing area. The ventilation circuit is then wider and improves the efficiency of gas regeneration.

These orifices may not be perforated in the false bottom, but result from residual spaces remaining between the external container and said false bottom, when the latter is fitted therein and welded.

According to an important characteristic, the packaging of the invention must be provided with a tamper-proof water-absorbing pad. This is why the false bottom is generally welded to the container.

The outer container and the false bottom, made of synthetic material, are preferably made of polypropylene.

• la figure 1 est une perspective éclatée d'une configuration possible de l'invention, vue par dessus,
• la figure 2 est une seconde perspective éclatée de la même configuration vue par dessous, et
• la figure 3 est une coupe d'une barquette selon l'invention assemblée, avec ses trois éléments constitutifs en position de fonctionnement.

In the following, a description will be given in more detail of the packaging which is the subject of the present invention, with reference to the accompanying drawings, for which:

• FIG. 1 is an exploded perspective view of a possible configuration of the invention, seen from above,
• FIG. 2 is a second exploded perspective of the same configuration seen from below, and
• Figure 3 is a section of a tray according to the invention assembled, with its three components in the operating position.

These figures propose a configuration which should be considered as an example, and not as a limiting form of the invention. This exploded perspective represents the three constituent elements of the invention, namely the outer container (1), the buffer (2) and the false bottom (3).

Said outer container (1) comprises two types of reliefs to be distinguished, because they fulfill two different functions. First, the reliefs (4) intended to allow the circulation of the gaseous fluid. In this case, these are flat prismatic mounds (4) separated by channels (5) which intersect and open out in a peripheral zone (6) partially blocked by a second type of relief (7). The latter (7) are intended to support, or even fix (for example by welding, thermal or ultrasonic ...) the false bottom (3).

Of course, the upper surface of the first reliefs (4) of the bottom of the container (1) remaining flat, in order to serve as a support for the tampon, the peripheral shape of these mounds (4) does not matter, provided that the channels which separate them intersect to allow free passage of the gaseous fluid and they open into the peripheral zone (6).

Similarly, it is possible to add reliefs (7) supports of the false bottom (3) in the area of the mounds (4), respecting the same rules. In this case, the shape of the reliefs is unimportant, only the function account. As mentioned before, this type of packaging, the vocation of which requires that they be hermetically sealed, often has fairly high edges (8): this is the case here. In the upper part of the rim (8), a flat portion (9) parallel to the bottom allows the positioning and / or fixing of the false bottom (3).

When there is fixing, the rim (17) of the false bottom is welded at this shoulder (9), as well as at the reliefs (7). Generally, the container (1) and the false bottom (3) are welded in order to make the space between them inviolable. This shoulder (9) is extended by a terminal edge (10) on which the film is heat sealed (not shown).

The buffer (2) is applied between the reliefs (7) which help in its installation by delimiting its positioning area. It is provided with cylindrical holes (11) which pass right through it, and are arranged so as to be approximately centered on the flat mounds (4) for the reasons explained above, aiming in particular to prevent exudates from arrive in the channels (5).

These holes (11) correspond to the orifices (12) of the false bottom (3) with which they are substantially coaxial in the assembled position. The liquid penetrates there and is gradually absorbed by the tampon (2) at the walls of said holes (11). These vertical walls are therefore of great functional importance, as will also be seen hereinafter, in combination with the orifices (12) known as of the first group, those of the planar part (13) of the false bottom (3).

These (12) have in fact a funnel shape making it possible to guide the liquids which flow from the main volume of the container (V) into the cavities which form the holes (11) of the pad resting on the flat mounds (4 ) from the bottom of the container (1). The ends (16) of said funnels are preferably conical, and serve to trap the liquid in the volumes formed by the holes (11).

The false bottom (3) comprises two distinct parts: a flat bottom (13) bearing on said mounds (4), and flanges (14) which rise up towards the upper peripheral edge (10) of the container (1), substantially parallel to the edges of said container (1).

Figure 2 shows particularly clearly the end portions (16) funneling the orifices (12) of the first group, protruding from the surface (13) of the false bottom (3) to be inserted in the corresponding holes (11) of the buffer (2).

Figure 3 is a cross section, but a longitudinal section would have been strictly equivalent, due to the existence of symmetry with respect to a central axis perpendicular to the bottom of the tray. It shows the systematic offset that exists between the channels (5) of the bottom of the container and the funnels (12) of the false bottom (and therefore the holes (11) of the buffer).

This view shows more explicitly the shoulder (9) of the container (1), on which the false bottom is welded, which is also welded to the reliefs (7). Finally, it allows you to get a more precise idea of the nesting of the 3 elements of the tray.

The circulation of gas in the peripheral zones (6) towards the orifices of the second group (15) is also clearly demonstrated. The orifices (15) can also be residual spaces formed between the container (1) and the false bottom (3), at the level of the rim (17) for fixing the false bottom to the shoulder (9), and making office of ventilation points.

It should be noted that, in the terminology used previously, the word gas was used, and not the term air, inappropriate. In fact, the hermetically sealed container generally contains a gas injected at the time of sealing, the preservation properties of which are adequate.

It is this gas which is regenerated by the hydroreactive buffer, containing a specific chemical reacting with the fumes of the product placed in the atmosphere in particular due to this gas.

The object of the invention is mainly oriented towards the structure of the tray and its three elements, with variants which remain in the spirit of what is claimed. The chemical compositions of the inhibitor intended to neutralize the fumes of the products and of the regeneration reagent can be of all types without changing the nature of the invention.

The synthetic materials used for the manufacture of the container (1) and of the heat-sealed film can be complex, having characteristics preventing the crossing of gases, aromas and water vapor.

Claims (10)

1. Pack for packaging and storing for a long period, designed for fresh products which may tend to exude a liquid which may significantly reduce their shelf life, including an outer receptacle (1) in which there are disposed a pad (2) of the water-capture type, at the bottom of the said receptacle (1), and a false bottom (3) fitted in the latter, on which the product to be stored rests, the whole being hermitically sealed so as to ensure storage in a closed atmosphere, the false bottom (3) having a first group of orifices (12) enabling the exuded liquid to be brought into contact with the pad, and a second group of orifices (15) situated between the containing volume (V) of the package and a volume defined between the receptacle (1) and the false bottom (3) and/or the parts of the pad which are not in contact with the exudate, so as to establish gaseous exchanges between the two volumes mentioned, the respective shapes of the false bottom (3) and of the pad (2) being designed so as to prevent any contact between the product to be stored and the said pad (2), characterised in that the outer receptacle (1) has indentations (4, 5) designed to establish gaseous circulation between the pad (2) and the bottom of the said receptacle (1), the said indentations forming areas for passage to the orifices (15) in the second group.
2. Packaging pack according to Claim 1, characterised in that the said indentations are channels (5) disposed between raised areas (4) with a flat bottom designed to support the pad (2), the said channels intersecting and opening out in a peripheral area (6) of the said bottom communicating with the orifices (15) in the second group.
3. Packaging pack according to one of the preceding claims, characterised in that the outer receptacle also has indentations (7) designed to support and/or to fix the false bottom (3), disposed so that they do not prevent gaseous passage towards the orifices (15) in the second group.
4. Packaging pack according to one of the preceding claims, characterised in that the pad (2) has orifices (11) disposed opposite the orifices (12) in the false bottom (3) in the said first group, and forming small exudate reservoirs whilst the liquid is in the course of being absorbed by the pad (2).
5. Packaging pack according to Claim 4, characterised in that the said holes (11) in the pad (2) are not positioned opposite the channel-shaped gaseous discharge conduits (5).
6. Packaging pack according to one of Claims 4 and 5, characterised in that the orifices (12) in the first group have a portion projecting beyond the flat-shaped part (13) on which the product rests and entering the spaces defined by the orifices (11) in the pad, and which has a funnel shape (16).
7. Packaging pack according to Claim 6, characterised in that the ends (16) of the said funnels are flared, so as to trap the liquid in the spaces formed by the orifices (11) in the pad.
8. Packaging pack according to any one of the preceding claims, characterised in that the orifices (15) in the second group are situated in the part of the false bottom (3) which is substantially parallel to the peripheral edges (14) of the receptacle (1), and close to the area (9) where the said false bottom (3) is fixed to the receptacle (1).
9. Packaging pack according to any one of the preceding claims, characterised in that the receptacle (1) and the false bottom (3) are made of polypropylene.
10. Packaging pack according to any one of the preceding claims, characterised in that the water-capture pad (2) is tamper-proof since the false bottom (3) is welded to the receptacle (1).

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