Patent Description:
A typical food package available on the market, such as the one in <FIG>, is made by means of a "flow pack" type machine and contemplates a single sheet of plastic film folded on itself around the food product. The so obtained package requires three welding zones A, B1, B2: one (A) to join the laminate with itself and two (B1, B2) to close the ends of the package. The food product, in case it needs a support, can be supported by a tray, which is then also inserted inside the package. This type of very common packaging can be filled with modified atmosphere if necessary, but this technology does not allow sufficient evacuation of oxygen to guarantee the quality of sliced food products, which even in presence of moderate quantities of oxygen in the modified atmosphere inside the package may change colour and flavour due to oxidative processes.

Furthermore, these oxygen residues may differ from package to package and it is thus difficult to guarantee the quality of the packaged product over a long period and on different samples. Finally, the welding is weak at the joints, and this can favour micro leaks that may cause in a short time an increase of residual oxygen inside the package and thus a rapid deterioration of the product.

In order to obviate these problems, particularly felt for example in the case of packaging of sliced meats, packages for food products such as that of <FIG> made through a thermoforming machine are used. During this packaging process, a vacuum is created inside the package before injecting a modified atmosphere, obtaining a protected atmosphere inside. In this way it is possible to reduce residual oxygen percentages by an order of magnitude, and thus to obtain a better conservation of the product.

The package of this type includes a lower tray V in thermoformed plastic material with a thickness not smaller than <NUM> micrometers. This thickness is necessary for having a rigid tray, as shown in the sectional view of <FIG>, that does not to bend due to the weight of food when a consumer picks it up. The tray containing a food products is then closed with an upper plastic film which typically has a thickness of no less than <NUM> micrometers and which is welded onto an edge of the underlying tray. Since the tray is rigid, the plastic film remains substantially flat and does not rest on the bottom of the tray.

However, in order to give the desired stiffness, a significant amount of plastic material is used. Furthermore, the plastic material of the lower tray is generally not recyclable because it is composed of several layers of different plastic films coupled together (typically a layer for stiffness, a layer for UV and oxygen barrier and a layer that welds with the other film).

<CIT> shows in Figure <NUM> a package according to the preamble of claim <NUM>, showing an outer cover having a lower part which is a rigid tray intended to contain pieces of meat, which are relatively heavy. It is to be remarked in particular that the lower part <NUM> is rigid and cannot collapse, because it supports both the closed trays containing the product without changing its shape and the upper part <NUM> which does not rest on the content <NUM>. The lower film, in this case, is flexible but not collapsible, i.e. it cannot be creased and crumpled into a ball with hands without any effort or folded more easily than a paper tissue.

<CIT> shows a cover not composed of two collapsible films, but of a single film folded on itself and sealed at the edges. The cover is inflated, as in the package of <FIG>, so as to define a housing much larger than the containment volume of the internal tray. The final appearance of the package is noticeably different from that of ordinary trays for sliced food, which is what it is desired to reproduce. This is due to a wise use of a thermoformed film, which makes the shape of the external packaging much more suitable for that of the internal tray than a bag. Furthermore, in this case, using a thermoforming machine instead of the machine of <FIG> in <CIT>, the production speed is much higher and the oxygen residues in the outer pack are lower than those obtained in the patent description. More precisely, using a thermoforming machine, which is able to make a vacuum up to 10mbar instead of the 372mbar of the machine in <FIG> in <CIT>, and thanks to the fact that the inner pack does not have a lid, unlike the one described in <CIT>, the oxygen residues are much lower than those described in the patent. In fact, as stated at paragraph [<NUM>], "Taking into account any oxygen disposed within the inner package <NUM>, i.e., oxygen disposed within the meat <NUM> itself, the wall of the tray <NUM>, and the free space beneath the stretch film <NUM>, the oxygen level in the pocket <NUM> of no less than about <NUM>,<NUM> percent corresponds to an 'equilibrium' oxygen level in the entire package <NUM> of no less than one to two percent". The package and packaging procedures presented in this application allow to reduce oxygen residues below <NUM>% from the moment the pack is closed, thus also avoiding the use of oxygen scavengers.

Both packaging of patents <CIT> and <CIT> are composed of an "internal packaging", also called "finished package" in <CIT>, and an "external packaging" (which serves to preserve the product during the journey from manufacturer to distributor), also called "master container" in <CIT>. The difference is that, in these cases, the "internal packaging" is a closed container which is the packaging of the product for the final consumer. The inner tray of the packaging disclosed in the present document is a tray without a lid, it cannot be sold without the outer packaging (the thermoformed plastic bag). Therefore, the package, as it reaches a consumer, in the case of packages presented in <CIT> and <CIT> is very different from the package of the present description.

An objective of the present invention is to provide a package for food products which:.

A further object of the present invention is to provide a packaging process for the aforementioned food package which is easy to adopt in the production lines currently in use.

These objects are achieved with a food package the main characteristics of which are specified in the enclosed claims.

<FIG> depict a food package comprising a welded cover <NUM> and a tray <NUM> configured to be inserted inside the welded cover <NUM> and to contain food. The tray has a bottom and raised edges with respect to the bottom having a nominal height, so as to define together a volume for containing the food product inside the tray <NUM>. The welded define together a volume for containing the food product inside the tray <NUM>. The welded cover <NUM> comprises a lower plastic film <NUM> and an upper plastic film <NUM> distinct and separate from the lower plastic film <NUM>. These used films are produced by coupling one or more plastic films chosen the set, by way of example but not limited to, consisting of polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP) or combinations thereof and by adding an oxygen and UV barrier.

According to one aspect, the lower plastic film <NUM> and the upper plastic film <NUM> are preferably composed of the same material. According to one aspect, the lower plastic film <NUM> and the upper plastic film <NUM> have different thicknesses and optionally also a barrier to oxygen and UV rays which can affect in different percentages.

Furthermore, the lower plastic film <NUM> and the upper plastic film <NUM> have materials and thicknesses of such dimensions as to make them both collapsible, that is, they lack sufficient rigidity to keep their shape intact when held cantilevered at only one end. In other words, the considered films can be creased and crumpled into a ball with bare hands without effort. The reduced thickness makes it possible to greatly reduce the amount of plastic material necessary for the production of the food package according to this disclosure. In this way, the external films have only the function of protecting the food product from the outside, from oxygen and UV rays.

According to the invention, the lower plastic film <NUM> has a thickness of between <NUM> micrometers and <NUM> micrometers, and the upper plastic film <NUM> has a thickness of between <NUM> micrometers and <NUM> micrometers. Tests carried out by the Applicant have shown that the use of a thermoforming machine allows the food to be packaged, reaching a residual oxygen content of less than <NUM>% inside the package, which allows the appearance of the sliced meats to be kept practically unaltered until the expiry date.

The lower plastic film <NUM> and the upper plastic film <NUM> are welded to each other at respective perimeter edges 10a, 11a so as to form the welded cover <NUM> and to define a closed, watertight internal housing. Welding is preferably carried out with a heat-sealing process, but other equivalent methods are possible such as, by way of example but not limited to, ultrasonic welding.

As shown in <FIG>, the tray <NUM> is inserted in this closed internal housing and is not fixed to the lower plastic film <NUM> or to the upper plastic film <NUM>; in other words, tray <NUM> is trapped in the closed watertight housing. The tray <NUM> is not collapsible, that is, if cantilevered held at one end it is at least capable of supporting its own weight and maintaining its shape. Furthermore, the tray <NUM> is configured to support the weight of the food product that is housed therein so that a buyer can lift the food package according to the present disclosure and the food package does not collapse under the weight of the food product contained therein.

According to the invention, the lower plastic film <NUM> is thermoformed to better adapt to the shape of the tray <NUM>. In addition, the upper plastic film <NUM> can be thermoformed. According to the invention, the lower plastic film <NUM> is thermoformed so that the watertight internal housing has a volume comparable to the containment volume of the tray <NUM>, with the lower thermoformed plastic film <NUM> enveloping the outer surface of the tray. As shown in <FIG>, the upper plastic film <NUM> will be conveniently configured to rest against the edges of tray <NUM> and to be supported by the raised edges of tray <NUM>, remaining cantilevered suspended above the bottom of tray <NUM>. In this way, the complete package will have the appearance of common trays for cold cuts, like the one shown in <FIG>, but with a much thinner lower plastic film <NUM>.

Given the collapsibility of the lower plastic film <NUM> and of the lower plastic film <NUM>, the shape of the outer cover could change substantially due to the force of gravity or other external forces. The shape of the pack for cured meats described in this document is thus preserved by the internal tray, by its shape and its mechanical strength.

Furthermore, the perimetral welding between the upper plastic film <NUM> and the lower plastic film <NUM> is configured to abut against the raised edges of the tray, keeping the upper plastic film <NUM> substantially flat, preventing it from lying on the bottom of the tray <NUM>.

According to one aspect, the tray <NUM> is made, by way of example but not limited to, of paper or of compostable material.

According to one aspect, the paper-based tray is coated with a light polymer layer or another barrier to protect the paper from moisture.

According to the invention, the watertight internal housing of the food package, after having been made under vacuum, is filled with a modified atmosphere suitable for food preservation.

A welded cover <NUM> with these characteristics has the advantage of having low oxygen residues inside the package, thus the quality of the product can be preserved for a long time. Furthermore, the food package comprising the welded cover <NUM> and the tray <NUM> preserves the rigidity and properties of trays for cold cuts available on the market produced with a thermoforming machine, and at the same time reduces consumption of plastic, as in the packages produced with a flow pack machine.

The fact of not having an oxygen permeable lid on the tray containing the product allows to realize better vacuum conditions and to have oxygen residues in the air around the product of less than <NUM>% already when the package is sealed.

Referring to <FIG>, the process for producing a food package according to the present disclosure, an example of which is depicted in <FIG>, comprises the following steps:.

In step a) it is possible to carry out the forming operation only on the lower film <NUM> and also optionally on the upper film <NUM>.

It is understood that steps b) and c) can be switched. The tray <NUM> supports its own weight and the weight of the food placed inside, thus it can be placed on the lower laminated plastic film <NUM>, before or after the insertion of the food into the tray itself.

The embodiment of the method of this disclosure shown in <FIG> refers to the case in which the upper plastic film <NUM> is taken from a first continuous film roll and the lower plastic film <NUM> is taken from a second continuous film roll. Consequently, after the two upper and lower films are welded together (step g), they must be cut (step h), in correspondence with the respective perimeter edges in order to separate the single packages.

Although less preferred, the latter operation could theoretically be avoided by providing a pre-cut upper plastic film <NUM> and a pre-cut lower plastic film <NUM> having suitable length. The food package according to the present disclosure has the advantage of reducing more than <NUM>% the used amount of plastic material than a thermoformed package according to the prior art, while maintaining the necessary rigidity of the package thanks to the internal tray. A further advantage is the fact that this tray <NUM> is recyclable or compostable.

Furthermore, the packaging process according to this disclosure allows to preserve the best quality of the product thanks to the reduced percentages of oxygen present inside the obtained package.

Advantageously, the food package according to the present disclosure does not require the lower plastic film to comprise a layer of a different material suitable for imparting rigidity to the package. In this way, not only is the lower film more easily recyclable, but it is also possible to use a lower film and an upper film based on the same plastic material, thus improving the ease of recycling of the welded cover <NUM> as a whole. Finally, the process can be easily adopted in the production lines that are currently in use for the production of rigid thermoformed tray packages.

Claim 1:
A food packaging, including:
- a welded cover (<NUM>) composed of a lower plastic film (<NUM>) and an upper plastic film (<NUM>) distinct and separate from said lower plastic film (<NUM>), said upper and lower films having thicknesses and being composed of materials such as to be collapsible, and being welded together at respective perimeter edges (10a, 11a) so as to define a perimetral sealing and a watertight internal housing;
- a non-collapsible tray (<NUM>) inserted in said closed internal housing, detached from said lower film and said upper film, trapped in said sealed housing, said tray being configured to house the food product and to support its weight, said tray having a bottom and raised edges in respect to the bottom and having a nominal height and defining together a containment volume of the food product inside the tray (<NUM>);
wherein said sealed housing is filled with a modified atmosphere suitable for food packaging;
wherein said lower plastic film (<NUM>) is thermoformed to contain said non-collapsible tray (<NUM>) so that the internal sealing housing has a volume corresponding to the containment volume of the tray with the thermoformed lower plastic film (<NUM>) wrapping an outer surface of the tray, the upper plastic film (<NUM>) being configured to remain suspended above the bottom of the tray (<NUM>);
characterized in that
said lower plastic film (<NUM>) has a thickness of between <NUM> micrometers and <NUM> micrometers, and said upper plastic film (<NUM>) has a thickness of between <NUM> micrometers and <NUM> micrometers;
said upper and lower films having thicknesses and being composed of materials such as to be creased and crumpled with bare hands into a ball or folded as a paper tissue;
the upper plastic film (<NUM>) is configured to lie on the edges of the tray (<NUM>) and to be sustained by the raised edges of the tray (<NUM>).