“Packaging apparatus and process”

DESCRIPTION

FIELD OF THE INVENTION

The present invention relates to a new process of packaging a product. The invention also relates to a new apparatus for making a package containing a product. The process and apparatus of the invention may find a specific field of use in the packaging of food products. The apparatus and process of the invention are configured to form a package having at least one stiffening member in the form of tubular element housing a gas.

BACKGROUND OF THE INVENTION

It is common in food packaging operations for a food product to be placed on a rigid tray of the type having a base, a sidewall and a peripheral flange. The function of the tray is generally that of providing a containment zone for the product and to offer a substantially rigid support. A thermoplastic film is then positioned over the food and heat sealed to the peripheral flange of the tray to hermetically enclose the food product. In these type of packages, a significant percentage of the final packaging costs is due to the relatively high cost of the trays. In addition, due to the thickness of the material forming the tray, the weight and volume of packaging remains quite high especially compared to the weight of the contained product, thus resulting in higher costs for shipping and storing. In general, there are costs and inconveniences associated with transporting and storing the trays before their use in the packages. Also, such trays add to the volume of packaging waste material with which the consumer must deal after opening the package.

In order to solve the above problems, WO 03051740 A2 and WO 2016174111 A1 disclose a package formed by top and bottom opposing films fixed together to form a chamber portion that is capable of containing the product and a hollow frame surrounding the chamber portion and providing the overall package with a certain stiffness. The package may be formed using a top chamber casing and opposing bottom chamber casing. The top and bottom chamber casings are moveable relative each other between a chamber open mode, where the top and bottom casings and are spaced apart to allow the top film and bottom film bearing the product to enter the heat closure chamber defined by the two casings, and a chamber closed mode, where the top and bottom casings are proximate each other to form an enclosed chamber volume. The top chamber casing carries an inner heating bar and an outer heating bar, which may be sequentially moved to form an inner seal between the top and bottom films around the product and to then form the hollow frame surrounding the product. Although the above solutions resulted in extremely appreciable products and processes, the Applicant envisaged ways to further improve the described prior art solutions. SCOPE OF THE INVENTION

It is a goal of the present invention providing an improved apparatus and a process for manufacturing a package of the type formed using top and bottom films defining a watertight chamber portion containing the product and a hollow frame adjacent to the chamber portion.

Furthermore, it is an aim of the invention providing simplified process and apparatus for making the mentioned package.

Additionally, it is an aim of the invention providing a process and apparatus for making the mentioned package wherein formation of vacuum in the chamber portion may be obtained in an efficient manner.

Moreover, it is an auxiliary aim providing a process and apparatus for making the mentioned package wherein inflation of gas in the hollow frame optionally in combination with formation of vacuum in the chamber portion may be obtained in an efficient manner.

Finally, it is an ancillary aim of the invention providing a process and apparatus for making the mentioned package which may be adapted to operate using continuous top and bottom films, or using discrete top and/or bottom film sheets or using a preformed support instead of the bottom film.

These and other objects, which will become more apparent from the following description, are achieved by an apparatus and process according to what is expressed in one or more of the accompanying claims and/or the aspects or features described below.

SUMMARY

One or more of the above goals are reached by a process according to any one of the appended process claims. One or more of the above goals are also reached by an apparatus according to any one of the appended apparatus claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments and some aspects of the invention are described hereinafter with reference to the accompanying drawings, provided only for illustrative and, therefore, non-limiting purposes, in which:

- Figures 1 and 2 show a possible structure of a packaging apparatus according to the present invention;

- Figures 3-8 show a first embodiment of a packaging of a packaging apparatus according to the present invention during various phases of a packaging cycle;

- Figure 9 is a detailed view of the packaging assembly of figure 3;

- Figure 9A is a detailed view of the packaging assembly of figure 6;

- FIG. 10 is a detailed view of the packaging assembly of figure 8;

- Figures 11-14 show a second embodiment of a packaging apparatus according to the present invention during various phases of a packaging cycle;

- Figures 15-19 show a third embodiment of a packaging apparatus according to the present invention during various phases of a packaging cycle; - Figure 20 is a top view of a package obtainable by a packaging apparatus, and a related packaging process, according to the present invention.

CONVENTIONS

In the present detailed description, corresponding parts illustrated in the figures are indicated by the same reference numerals. The figures may illustrate the object of the invention by representations that are not in scale; therefore, parts and components illustrated in the figures relating to the object of the invention may relate to schematic representations.

The terms upstream and downstream refer to a direction of advancement of a top film and/or of a bottom support for making a package along a predetermined path starting from a starting or forming station of said bottom support or said top film up to a packaging station where said bottom support and said top film are used in order to form said package.

DEFINITIONS

Product

The term product P means an article or a composite of articles of any kind. For example, the product may be of a foodstuff type and be in solid, liquid or gel form, i.e. in the form of two or more of the aforementioned aggregation states. In the food sector, the product may comprise: meat, fish, cheese, treated meats, prepared and frozen meals of various kinds.

Control unit

The apparatus described and claimed herein includes at least one control unit designed to control the operations performed by the apparatus. The control unit may be only one or be formed by a plurality of different control units according to the design choices and the operational needs.

The term control unit means an electronic component which can comprise at least one of: a digital processor (for example comprising at least one selected from the group of: CPU, GPU, GPGPU), a memory (or memories), an analog circuit, or a combination of one or more digital processing units with one or more analog circuits. The control unit may be "configured" or "programmed" to perform some steps: this may be done in practice by any means that allows configuring or programming the control unit. For example, in the case of a control unit comprising one or more CPUs and one or more memories, one or more programs may be stored in appropriate memory banks connected to the CPU or to the CPUs; the program or programs contain instructions which, when executed by the CPU or the CPUs, program or configure the control unit to perform the operations described in relation to the control unit. Alternatively, if the control unit is or includes analog circuitry, then the control unit circuit may be designed to include circuitry configured, in use, for processing electrical signals so as to perform the steps related to control unit. The control unit may comprise one or more digital units, for example of the microprocessor type, or one or more analog units, or a suitable combination of digital and analog units; the control unit may be configured for coordinating all the actions necessary for executing an instruction and instruction sets.

Actuator

The term actuator means any device capable of causing movement on a body, for example on a command of the control unit (reception by the actuator of a command sent by the control unit). The actuator may be of an electric, pneumatic, mechanical (for example with a spring) type, or of another type.

Suction source

The term suction source may designate a single suction source or a plurality of independent suction sources.

Gas source

The term gas source may designate a single gas source or a plurality of independent gas sources.

Bottom support

The bottom support may be made of a sheet material at least partially made of plastic material. In particular, the bottom support may comprise at least a film sheet of plastic material. For example, the bottom support may be made at least in part of a mono-layer film and/or of a multilayer film, optionally made in thermoplastic material. The bottom support may be provided with gas barrier properties. As used herein, this term refers to a film or sheet of material that has an oxygen transmission rate of less than 200 cm ³ /(m ² * day * bar), less than 150 cm ³ /( m ² * day * bar), less than 100 cm ³ /(m ² * day * bar) when measured in accordance with ASTM D-3985 at 23° C and 0% relative humidity. Gas barrier materials suitable for single-layer thermoplastic containers are e.g. polyesters, polyamides, ethylene vinyl alcohol (EVOH), PVdC and the like.

The bottom support may be made of multilayer material, optionally a multilayer film sheet material, comprising at least one gas barrier layer and at least one heat-sealable layer to allow sealing the covering film on the surface of the bottom support. The gas barrier polymers which can be employed for the gas barrier layer are PVDC, EVOH, polyamides, polyesters and mixtures thereof. Generally, a PVDC barrier layer will contain plasticizers and/or stabilizers as known in the art. The thickness of the gas barrier layer will be set in order to provide the material of which the bottom support is composed with an oxygen transmission rate at 23 °C and 0% relative humidity of less than 50 cm ³ /(m ² * day * atm), optionally less than 10 cm ³ /(m ² * day * atm), when measured in accordance with ASTM D-3985.

In general, the heat-sealable layer will be selected from polyolefins, such as ethylene homo- or copolymers, propylene homo- or copolymers, ethylene/vinylacetate copolymers, ionomers and homo- or co-polyesters, e.g. PETG, a glycol-modified polyethylene terephthalate.

Additional layers, such as adhesive layers, for example to make the gas barrier layer better adhere to the adjacent layers, may preferably be present in the material of which the bottom support is made and are selected based on the specific resins used for the gas barrier layer. A frangible layer that is easy to open can be positioned adjacent to the thermo-weldable layer to facilitate the opening of the final packaging. Blends of low-cohesion polymers which can be used as a frangible layer are for example those described in W099/54398. The overall thickness of the bottom support will be typically, but not limited to, up to 5 mm, optionally comprised between 0.04 and 3.00 mm and more optionally between 0.05 and 1.50 mm, even more optionally between 0.07 and 1.20 mm).

The bottom support may be made entirely made of a film in plastic material. In a further embodiment, the bottom support is at least partly made of paper material and at least partly of plastic material; in particular, the bottom support is made internally of plastic material and externally covered at least partly in paper material.

The bottom support may also be used to define so-called ready-meal packages; in this configuration, the bottom supports are made so that they can be inserted in the oven for heating and/or cooking the food product placed in the package. For example, bottom supports suitable for ready-meal packages may be made of CPET, APET or APET/CPET, foamed or non-foamed materials. The bottom support may further comprise a hot-weldable layer of a low melting material on the film. This hot-weldable layer can be co-extruded with a PET-based layer (as described in the patent applications No. EP 1 529797A and W02007/093495) or it can be deposited on the base film by means of deposition with solvent means or by means of extrusion coating (e.g. described in the documents US 2,762,720 and EP 1 252008 A).

Top film

A top film made of plastic material, in particular polymeric material, is applied to the bottom support (flat supports or trays), so as to create a fluid-tight package housing the product P. In order to make a vacuum pack, the top film applied to the bottom support is typically a flexible multilayer material comprising at least a first outer heat- sealable layer capable of welding to the inner surface of the bottom support, optionally a gas barrier layer and a second, heat-resistant outer layer.

If it is desired to make a modified atmosphere package (MAP) or a package under natural atmosphere (non- modified atmosphere), the top film applied with the bottom support (film made of plastic, in particular polymeric material) may typically be single-layer or multilayer. In the case of a multilayer sheet, the top film may comprise at least one of: one or more gas barrier layers, one or more heat-sealable layers (layers adapted to allow a plastic film to be welded to the support), one or more heat-resistant layers, one or more outer layers (for example polyamide or polypropylene or polyester).

For use in a skin-pack or VSP packaging process, plastic materials, especially polymers, should be easily formed as the top film needs to be stretched and softened by contact with the heating plate before it is laid on the product and the bottom support. The top film must rest on the product conforming to its shape and possibly to the internal shape of the bottom support.

The heat-sealable (for example outer) layer may comprise any polymer capable of welding to the inner surface of the bottom support. Suitable polymers for the heat-sealable layer can be ethylene and ethylene copolymers, such as LDPE, ethylene/alpha-olefin copolymers, ethylene/acrylic acid copolymers, ethylene/vinyl acetate copolymers or ethylene/vinyl acetate copolymers, ionomers, co-polyesters, for example PETG. Preferred materials for the heat-sealable layer are LDPE, ethylene/alpha-olefin copolymers, e.g. LLDPE, ionomers, ethylene/vinyl acetate copolymers and mixtures thereof.

Depending on the product to be packaged, the film may comprise a gas barrier layer. The gas barrier layer typically comprises oxygen-impermeable resins such as PVDC, EVOH, polyamides and mixtures of EVOH and polyamides. Typically, the thickness of the gas barrier layer is set to provide the film with an oxygen transmission rate of 23 °C and 0% relative humidity of , less than 100 cm ³ /m ² * m ² * atm, preferably less than 50 cm ³ /(m ² * day * atm), when measured in accordance with ASTM D-3985. Common polymers for the heat-resistant outer layer are, for example, ethylene homo- or copolymers, in particular HDPE, ethylene copolymers and cyclic olefins, such as ethylene/norbornene copolymers, propylene homo- or copolymers, ionomers, polyesters, polyamides.

The top film in its multilayer form may further comprise other layers such as adhesive layers, filling layers and the like to provide the thickness necessary for the top film and improve its mechanical properties, such as puncture resistance, abuse resistance, formability and the like. The top film is obtainable by any suitable co extrusion process, through a flat or circular extrusion head, optionally by co-extrusion or by hot blow molding. Again, for use in a skin-pack or VSP packaging process, the top film is substantially non-oriented. Typically, the top film, or only one or more of its layers, is cross-linked to improve, for example, the strength of the top film and/or heat resistance when the top film is brought into contact with the heating plate during the vacuum skin packaging process. Crosslinking can be achieved by using chemical additives or by subjecting the film layers to an energy-radiation treatment, such as high-energy electron beam treatment, to induce crosslinking between molecules of the irradiated material. Films suitable for this application may have a thickness in the range between 50 pm and 500 pm, optionally between 60 pm and 3000 pm, even more optionally between 65 pm and 100 pm.

For use in packaging processes of products under controlled atmosphere (MAP) or in a natural atmosphere (unmodified atmosphere), the top film applied to the bottom support (plastic film, in particular polymeric) is typically mono-layer or multilayer, having at least one heat-sealable layer, optionally capable of thermo- retracting under heat action. The applied top film may further comprise at least one gas barrier layer and optionally a heat-resistant outer layer. In particular, the top film can be obtained by co-extrusion and lamination processes. The top film may have a symmetrical or asymmetrical structure and may be single-layer or multilayer. Multilayer films are composed of at least two layers, more frequently at least five layers, often at least seven layers.

The total thickness of the top film may range from 30 pm to 500 pm, optionally from 40 pm to 300 pm, even more optionally from 50 pm to 200 pm; in one embodiment the film, has a thickness of between 65 pm and 100 pm.

The top films may possibly be cross-linked. Crosslinking can be achieved by irradiation with high energy electrons at an appropriate dosage level as known in the art. The films described above can be heat-shrinkable or heat-curable. Heat-shrinkable films normally show a free shrinking value at 120 °C (value measured in accordance with ASTM D2732, in oil) in the range from 2% to 80%, normally from 5% to 60%, in particular from 10% to 40% in both longitudinal and transverse directions. Heat-curable films normally have a shrinkage value of less than 10% at 120 °C, normally less than 5% both in the transverse and longitudinal direction (measured in accordance with the ASTM D2732 method, in oil). Films normally comprise at least one heat-sealable layer and an outer layer (the outermost) generally consisting of heat-resistant polymers or polyolefins. The welding layer typically comprises a heat-sealable polyolefin which in turn comprises a single polyolefin or a mixture of two or more polyolefins such as polyethylene or polypropylene or a mixture thereof. The welding layer may also be provided with anti-fogging properties through known techniques, for example by incorporation in its composition of anti-fogging additives or through a coating or a spraying of one or more anti-fogging additives that counteract the fogging on the surface of the welding layer. The welding layer may also comprise one or more plasticizers. The outermost layer may comprise polyesters, polyamides or polyolefins. In some structures, a mixture of polyamide and polyester can be used for the outermost layer. In some cases, the films include a gas barrier layer. Barrier films normally have an oxygen transmission rate, also called OTR (Oxygen Transmission Rate) below 200 cm ³ /(m ² * day * atm) and more frequently below 80 cm ³ /(m ² * day * atm) evaluated at 23 °C and 0% RH measured in accordance with the ASTM D-3985 method. The barrier layer is normally made of a thermoplastic resin selected from a saponified or hydrolyzed product of ethylene-vinyl acetate copolymer (EVOH), an amorphous polyamide and vinyl-vinylidene chloride and mixtures thereof. Some materials include an EVOH barrier layer, layered between two polyamide layers. In some packaging applications, films do not include any gas barrier layer. These films usually comprise one or more polyolefins as defined herein.

Non-gas barrier films normally have an OTR (evaluated at 23 °C and 0% RH in accordance with ASTM D-3985) of 100 cm ³ /(m ² * day * atm) up to 10000 cm ³ /(m ² * day * atm), more often up to 6000 cm ³ /(m ² * day * atm). Peculiar compositions based on polyester are those used for the films of the so-called ready-meals. For these films, the polyester resins of the film may constitute at least 50%, 60%, 70%, 80% and 90% by weight of the film. These films are normally used in combination with supports, especially trays, made from polyester.

In the case of packages for fresh red meat, a double film may be used, comprising an oxygen permeable inner film and an oxygen impermeable outer film. The combination of these two films greatly prevents discoloration of the meat even in the most critical situation in the barrier packaging of fresh meat or when the packaged meat extends outside the cavity defined by the tray, or in which the product emerges from the upper perimetral edge of the lateral wall. These films are described for example in European patent applications EP1848635 and EP0690012.

The top film may be single-layer. The typical composition of the single-layer films comprises the polyesters as defined herein and mixtures thereof or the polyolefins as defined herein and mixtures thereof.

In all the top film layers described herein, the polymeric components may contain suitable amounts of additives normally included in such compositions.

Some of these additives are normally included in the outer layers or in one of the outer layers, while others are normally added to the inner layers. These additives include slipping or anti-blocking agents such as talc, waxes, silica and the like, or antioxidant agents, stabilizers, plasticizers, fillers, pigments and dyes, cross-linking inhibitors, cross-linking agents, UV absorbers, odor absorbers, oxygen absorbers, bactericides, antistatic agents, antifog agents or compositions and similar additives known to the man skilled in the art of packaging. Furthermore, the films described herein can be formulated to provide strong welds with the bottom support or tray or peelable from the tray/support. As described above, the film may be of a multilayer type and have at least one easy to open frangible layer which can be positioned adjacent a heat-sealable layer to facilitate the opening of the final packaging: the frangible layer is adapted to allow easy removal of the same film from the support to which it is associated. This film is described for example in the PCT patent application no. WO 2017/153434 A1. A method of measuring the strength of a weld, herein referred to as a "welding force, is described in ASTM F-88-00. Acceptable welding force values to have a peelable weld are between 100 g/25 mm and 850 g/25 mm, 150 g/25 mm to 800 g/25 mm, 200 g/25 mm to 700 g/25 mm.

The top film may be made of the same material as the bottom support, in particular the top film may comprise (optionally constituted) at least one sheet of plastic material. In particular the top film may be substantially the same as the film that defines the bottom support. In particular, the top film may comprise at least one plastic film which is substantially the same as the plastic film which forms the bottom support.

Although in the above sections, the structure of bottom support and top film has been described, thanks to the invention the bottom film may alternatively be made identical (including in term of thickness) to the top film thus providing evident savings in term of quantity of plastic or other material used for the overall packaging.

Material specifications

PVDC is any vinylidene chloride copolymer in which a prevalent amount of the copolymer comprises vinylidene chloride and a lower amount of the copolymer comprises one or more unsaturated monomers copolymerizable therewith, typically vinyl chloride and alkyl acrylates or methacrylates (for example methyl acrylate or methacrylate) and mixtures thereof in different proportions.

The term EVOFI includes saponified or hydrolyzed ethylene-vinyl acetate copolymers and refers to ethylene/vinyl alcohol copolymers having an ethylene co-monomer content preferably composed of a percentage of from about 28 mole% to about 48 mole%, more preferably from about 32 mole% and about 44 mole% of ethylene and even more preferably, and a saponification degree of at least 85%, preferably at least 90%.

The term polyamides is meant to indicate homo- and co- or ter-polymers. This term specifically includes aliphatic polyamides or co-polyamides, e.g. polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 69, polyamide 610, polyamide 612, copolyamide 6/9, copolyamide 6/10, copolyamide 6/12, copolyamide 6/66, copolyamide 6/69, aromatic and partly aromatic polyamides or copolyamides, such as polyamide 61 , polyamide 6I/6T, polyamide MXD6, polyamide MXD6/MXDI, and mixtures thereof.

The term polyesters refers to polymers obtained from the polycondensation reaction of dicarboxylic acids with dihydroxylic alcohols. Suitable dicarboxylic acids are, for example, terephthalic acid, isophthalic acid, 2,6- naphthalene dicarboxylic acid and the like. Suitable dihydroxylic alcohols are for example ethylene glycol, diethylene glycol, 1,4-butanediol, 1,4-cyclohexanodimethanol and the like. Examples of useful polyesters include polyethylene terephthalate) and copolyesters obtained by reaction of one or more carboxylic acids with one or more dihydroxylic alcohols.

The term copolymer means a polymer derived from two or more types of monomers and includes terpolymers. Ethylene homo-polymers include high density polyethylene (HDPE) and low-density polyethylene (LDPE). Ethylene copolymers include ethylene/alphaolefine copolymers and unsaturated ethylene/ester copolymers. The ethylene/alpha-olefin copolymers generally include copolymers of ethylene and one or more co-monomers selected from alpha-olefins having between 3 and 20 carbon atoms, such as 1 -butene, 1-pentene, 1 -hexene, 1-octene, 4-methyl-1-pentene and the like.

Ethylene/alpha-olefin copolymers generally have a density in the range of from about 0.86 g/cm ³ to about 0.94 g/cm ³ . It is generally understood that the term linear low density polyethylene (LLDPE) includes that group of ethylene/alpha-olefin copolymers which fall in the density range of between about 0.915 g/cm ³ and about 0.94 g/cm ³ and in particular between about 0.915 g/cm ³ and about 0.925 g/cm ³ . Sometimes, linear polyethylene in the density range between about 0.926 g/cm ³ and about 0.94 g/cm ³ is referred to as linear medium density polyethylene (LMDPE). Lower density ethylene/alpha-olefin copolymers may be referred to as very low-density polyethylene (VLDPE) and ultra-low-density polyethylene (ULDPE). Ethylene/alpha-olefin copolymers can be obtained with heterogeneous or homogeneous polymerization processes. Another useful ethylene copolymer is an unsaturated ethylene/ester copolymer, which is the ethylene copolymer and one or more unsaturated ester monomers. Useful unsaturated esters include vinyl esters of aliphatic carboxylic acids, in which esters have between 4 and 12 carbon atoms, such as vinyl acetate, and alkyl esters of acrylic or methacrylic acid, in which esters have between 4 and 12 carbon atoms, lonomers are copolymers of an ethylene and an unsaturated mono-carboxylic acid having the carboxylic acid neutralized by a metal ion, such as zinc or, preferably, sodium. Useful propylene copolymers include propylene/ethylene copolymers, which are copolymers of propylene and ethylene having a percentage by weight content mostly of propylene and propylene/ethylene/butene ter polymers, which are copolymers of propylene, ethylene and 1 -butene.

DETAILED DESCRIPTION

Packaging apparatus 100

With reference 100 it is indicated an apparatus for packaging a product P arranged between a bottom support 1 and a top film 2. The apparatus 100 is adapted for modified atmosphere packaging, where the top film 2 is applied to the bottom support 1 after a modified gas atmosphere has been created inside a volume defined between said bottom support 1 and top film 2. The apparatus 100 is further adapted for vacuum skin packaging of the product P, where the top film 2 is draped down on the product P and intimately adheres at least partially to said bottom support 1 as well as to the product surface thus leaving a minimum, if any, amount of air within the packaging. The apparatus 100 may also be used in case the top film 2 applied to the bottom support 1 and neither vacuum nor modified atmosphere is created, but just the sealing between the film 2 and the bottom support 1 is performed. The apparatus 100 comprises a frame 104 defining a base body configured to support various parts of the apparatus 100, including at least a packaging assembly 101 configured to receive at least a portion 1a of the bottom support 1 and a portion 2a of the top film 2 and to engage the portion 1a with the portion 2a forming a package 200 for a product P.

Although this should not be interpreted in a limitative manner, figures 1 and 2 disclose two possible alternative configurations of packaging apparatus including components additional to the packaging assembly. In particular the apparatus 1 may include:

- a bottom support supply assembly 103 configured for supplying the bottom support 1 ,

- a transport assembly 105 receiving the bottom support from the supply assembly 103 and configured for displacing the portions 1a of the bottom support 1 towards the packaging assembly 101,

- a product loading station 111 for positioning one or more products P onto respective one or more portions 1 a of the bottom support 1 ,

- a top film supply assembly 102 configured for supplying the top film 2 to the packaging assembly 101.

The transport assembly 105 may comprise a sliding plane 106 (as shown in the examples of figures 1 and 2), which may be, at least partially, a physical plane upon which the bottom support 1, in particular the portions 1a of the bottom support 1, is/are lying and sliding or an ideal plane along which the bottom support 1 is guided e.g. by means of railways or guides. The sliding plane 106 is defined on a top area of the frame 104 and may comprise an endless conveyor belt 107 positioned on the apparatus frame 104 according to a closed loop configuration. The conveyor belt 107 is for example driven by at least one driving roller 107a connected to a driving motor 105a, for instance a stepper electric motor, controlled by a control unit 50 for operating the conveyor belt 107 with step-by-step movement.

In the example shown in figures 1 and 2, the transport assembly 105 is carried by, e.g. fixed to, the frame 104 so that the sliding plane 106 is substantially horizontal and the conveyor 107 moves the bottom support 1 according to an horizontal direction indicated by the arrow A1. The transport assembly 105 (optionally the conveyor belt 107) is configured for displacing the bottom support 1 along a predefined path from the bottom support supply assembly 103 to the packaging assembly 101 where the portion 2a of the top film 2 is tightly fixed to the portion 1a of the bottom support 1, as it will be explained herein below in detail.

The conveyor 107 displaces the bottom support 1 inside the packaging assembly 101 in proper position for receiving the top film 2. For instance, a control unit 50 (which will be further described below) may control the conveyor 107 to displace a prefixed number of portions 1a per time from a region outside the packaging assembly 101, to a region inside the packaging assembly 101 where the portion or portions 1a are vertically aligned to respective top film portions 2a. The conveyor 107 may for instance include a transfer device 108 (see figure 2) configured for picking up one or more portions 1a of the bottom support 1 from the conveyor belt 107 and bringing them into the packaging assembly 101. Note that the products P may be positioned on the bottom support 1 (optionally on the portion 1a of the bottom support 1) either upstream the packaging assembly 101 (figure 1) or inside said packaging assembly 101 (figure 2).

As shown in figure 1, the bottom support supply assembly 103 may be configured for supplying a continuous film from a bottom film supply roll 112: consecutive portions 1a of the bottom support 1 correspond to consecutive portions of the continuous bottom film unrolled from the bottom film supply roll 112. The continuous film is positioned on the sliding plane 106 of the conveyor belt 107 and driven by this latter towards the packaging assembly 101. The bottom film supply roll 112 may be connected to an actuator or motor (not shown) configured to drive in rotation the supply roll allowing supply of the continuous film. The control unit 50 is connected to said actuator or motor of the bottom film supply roll 112 in order to control rotation of this latter and consequently control the release of the continuous film support on the conveyor belt 107. In one possible non-limitative variant, the control unit 50 may be configured to synchronize the step-by-step movement of the transport assembly 105 (in particular of the conveyor belt 107) with the rotation of the continuous film roll 112. The bottom support supply assembly 103 thus allows the one or more portions 1a of the bottom support 1 to move from the supply roll 112 to the transport assembly 105, optionally on the sliding plane 106 defined by a top surface of the conveyor belt 107; the conveyor belt 107 defines an operative tract configured for receiving a plurality of consecutive portions 1a.

Alternatively, the bottom supply assembly 103 may supply the bottom support film 1 in the form of portions 1a constituted by separate discrete film sheets as shown in figure 2. In this case, a cutting assembly (not shown) may be located outside the packaging assembly 101 and configured to cut a continuous film into the discrete film sheet. Alternatively, the cutting assembly may be placed between the continuous film supply assembly 103 similar to that of figure 1 and the packaging assembly 101, such that the cutting takes place before the bottom support 1 reaches the packaging assembly 101.

In the variant of figure 2, the portions 1a of the bottom support 1 are defined by a plurality of distinct discrete portions 1a stacked in a support loading station of the support supply assembly 103 configured for dispensing and loading the plurality of distinct portions 1a on the operative tract of the conveyor 107. In this configuration, the support loading station is connected to the control unit 50 of the apparatus 100 to control the dispensing and thus deposit of the one or more portions 1a of the bottom support 1 on the conveyor operative tract: for example, the control unit 50 may be configured for commanding the support loading station to position consecutive portions 1a on the operative tract such that each portion 1a is located at a pre-determined distance from an adjacent portion 1a. As shown in figure 2, the support loading station is configured for storing a plurality of said portions 1a and for sequentially supplying, under the control offered by the control unit 50, one or more portions 1a to the conveyor 107. The control unit 50 is connected to the transport assembly 105 and to the support loading station 103 in order to synchronize the discontinuous stepping movement of the transport assembly 105 with the positioning - executed by the support loading station - of the portions 1a on the sliding plane 106 of the same transport assembly 105.

The apparatus 100 of figures 1 and 2 has the product loading station 111 located downstream the support loading station 103 or downstream the bottom film supply roll 112 (with respect to the movement of the product P on the sliding plane 106 of the transport assembly 105): the product loading station 111 is configured for allowing the positioning of one or more products P onto respective one or more portions 1 a of the bottom support 1. The product loading station 111 may comprise an automatic dispenser of the products P controlled by control unit 50. Figure 1 shows a product loading station 111 arranged upstream the packaging assembly 101 so that the product P might be positioned on the respective portion 1a of the bottom support 1 before said portion 1a reaches the packaging assembly 101. Alternatively, the product loading station 111 is located at the packaging assembly 101 so that the product P might be positioned on the portion 1a already arranged inside the packaging assembly 101: this is for example the case of the apparatus of figure 2 where however the product loading station is not represented.

The top film supply assembly 102 comprises a top film supply roll 102a supplying a continuous top film 2. The continuous top film supply assembly 102 may comprise an arm 102b (represented in dashed lines in figures 1 and 2) fixed to the frame 104 and suitable for supporting the top film supply roll 102a. Note that the continuous top film 2 may be fed from the top film supply assembly 102 to the proper position inside the packaging assembly 101 with any known means, for instance using driving rollers or driving mechanisms acting upstream and/or downstream the packaging assembly 101, or using transport devices acting on the longitudinal borders of the top film 2, or combinations of the above means or any other suitable device. In detail, the continuous top film 2 is defined by a plurality of adjacent portions 2a aligned along an unwinding path of the top film 2. The top film supply roll 102a may be connected to an actuator or motor (not shown) configured to rotate the roll, hence allowing the supply of the continuous top film. The control unit 50 is connected to said actuator or motor of the top film supply roll 102a in order to control this latter in rotation and consequently control the release of the continuous top film 2. The control unit 50 may be configured to synchronize the step-by-step movement of the transport assembly 105 (in particular of the conveyor belt 107) with the rotation of the top film supply roll 102a and, consequently, with the bottom support supply assembly 103.

Alternatively, the top film supply assembly 102 may supply a continuous top film 2 to a cutting assembly 109 located outside the packaging assembly 101 and configured to cut the continuous top film 2 into said portions 2a constituted by separate discrete film sheets. The cutting assembly 109 may be placed between the top film supply assembly 102 and the packaging assembly 101, such that the cutting takes place before the top film portions 2a reach the packaging assembly 101 (see figure 2). A transport device 110 is configured for receiving the cut film portions 2a at the cutting assembly 109 and positioning the cut film portions 2a inside the packaging assembly 101. The control unit 50 of the apparatus 100 may be connected to and control operation of the cutting assembly 109 and of the transport device 110 to control deposition of the one or more portions 2a of the top film 2 on the transfer device 110 and to synchronize movement of the transfer device with the operation of the packaging station 101.

For the sake of illustrative but not limitative purpose, the portions 1a and 2a respectively of the bottom support 1 and of the top film 2 are both supplied to the packaging assembly 101 in a continuous manner as shown in figure 1, or they are both supplied to the packaging assembly 101 as discrete portions as shown in figure 2. It is not excluded that the portion 1a of the bottom support 1 may be supplied to the packaging assembly 101 in a continuous manner (figure 1), while the portion 2a of the top film 2 may be supplied as a discrete portion (figure 2), or vice versa.

Going now into a more detailed description of the packaging assembly 101, this latter is configured for tightly fixing each portion 2a of the top film 2 to a corresponding portion 1a of the bottom support 1. As described above, the portion 1 a of the bottom support 1 may be a portion of a continuous bottom support film (see figure 1) or one of said cut film sheets (discrete portions 1a as illustrated in figure 2); similarly, the portion 2a of the top film 2 may be a portion of a continuous film (see figure 1) or one of said cut film sheets (discrete portions 2a as illustrated in figure 2). In particular, the packaging assembly 101 includes a lower tool 6 and an upper tool 5 movable between at least one open condition, a closed condition and a sealing condition. The upper tool 5 and the lower tool 6, in the open condition (see figures 3, 4, 9, 11, 15 and 16), define an open chamber C: the upper and lower tool 5, 6, during the open condition, are configured to allow the access into said open chamber C of the portion 1a of the bottom support 1, of the product P positioned or to be positioned on the portion 1a of the bottom support 1, and of the portion 2a of the top film 2. The upper and lower tools 5, 6, in the closed condition delimit a closed chamber C hermetically closed with respect to an atmosphere outside the packaging assembly 101. Note that with hermetically closed it is meant that the packaging chamber C cannot freely communicate with the atmosphere outside the same chamber as gas may be supplied or withdrawn from the chamber C in a controlled manner only via predetermined supply or discharge channels of the apparatus 100, as it is further described here below.

In the sealing condition, the upper and lower tools continue to delimit a closed chamber (in the sense just explained) and in addition certain portions of the upper and lower tools are moved proximate to each other and configured to heat seal the portions 1 a, 2a of the bottom support 1 and of the top film 2 in order to fluid-tight seal the product P between said portions 1a, 2a.

Before further detailing operation of the upper and lower tools, a detailed description of the structure of these tools is provided.

The upper tool 5 comprises a respective tool central portion 42 configured to be located above the product P (see figure 4) and facing a tool central portion 31 of the lower tool 6. When properly positioned in the closed chamber C, the product P is located below the portion 2a of the top film 2 and below the central portion 42 of the upper tool 5. The tool central portion 42 of the upper tool 5 may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the lower tool 6.

The upper tool 5 further comprises a tool peripheral portion 43 surrounding said tool central portion 42 of the same upper tool 5 and directly facing a tool peripheral portion 32 of the lower tool (see e.g. figures 5-8). In particular, the tool peripheral portion 43 of the upper tool 5 extends around and wholly encircles the tool central portion 42 of the same upper tool 5. The tool central portion 42 and the tool peripheral portion 43 of the upper tool 5 delimit an active surface 5a. In detail, the tool peripheral portion 43 may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the lower tool 6. In greater detail, the tool peripheral portion 43 of the upper tool 5 shown in the examples of the attached figures defines:

- a respective inner abutting section 43a, for example having a bottom flat shape, wholly encircling the tool central portion 42 of the same upper tool 5,

- a respective outer abutting section 43b, for example having a bottom flat shape, wholly encircling the tool central portion 42 and the inner abutting section 43a of the same upper tool 5,

- a respective intermediate abutting section 43c connecting said inner abutting section 43a with said outer abutting section 43b. The intermediate abutting section 43c has a bottom concave shape (e.g., with a substantially 'C shaped profile - see figures 3, 4, 9, 9A and 10) with concavity facing the lower tool 6.

On its turn, the lower tool 6 comprises a tool central portion 31 configured for directly contacting and supporting the portion 1a of the bottom support 1, which as we already described serves for supporting said product P. The tool central portion 31 is configured to be located below the product P (see figure 4). Thus, when the product P is positioned in the closed chamber C, said product P is located above the portion 1a of the bottom support 1 and, specifically, above the central portion 31 of the lower tool 6. The tool central portion 31 may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the upper tool 5; the tool central portion 31 of the lower tool 6 may be provided with multiple seats in order to house a plurality of portions 1a and corresponding products P.

The lower tool 6 further comprises a tool peripheral portion 32 surrounding the tool central portion 31. In particular, the tool peripheral portion 32 of the lower tool 6 extends around and wholly encircles the tool central portion 31.

In greater detail, the tool peripheral portion 32 may have a flat shape or, as shown in the enclosed figures, may define at least one cavity, having concavity facing the upper tool 5. In detail, the tool peripheral portion 32 shown in the example of the attached figures defines:

- an inner abutting section 32a, for example having a top flat shape, wholly encircling the tool central portion 31,

- an outer abutting section 32b, for example having a top flat shape, wholly encircling the tool central portion 31 and the inner abutting section 32a,

- an intermediate abutting section 32c connecting the inner abutting section 32a with the outer abutting section 32b. The intermediate abutting section 32c has a top concave shape (e.g., with a substantially 'C shaped profile - see figures 3, 4, 9, 9A and 10) with concavity facing the upper tool 5.

The structure of the tool peripheral portion 43 of the upper tool 5 allows to form, in cooperation with the tool peripheral portion 32 of the lower tool 6, a hollow structure 4 during the sealing condition of the packaging assembly 101. In particular, the inner abutting section 43a and the inner abutting section 32a are configured to cooperate in the formation of the sealing band 3, while the intermediate abutting section 43c and the intermediate abutting section 32c, thanks to their concave conformation, are configured to cause formation of said one or more hollow structures 4. The outer abutting section 43b of the upper tool and the outer abutting section 32b of the lower tool are configured to ensure a complete fluid-tight sealing of the whole package 200 and of each hollow structure 4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band 3. It is indeed worth noting that, as shown in figure 20, after the sealing condition, the hollow structure 4 comprises at least one tubular section surrounding the central portion.

Finally, as shown in the enclosed figures, the shape of the tool peripheral portion 43 lower surface of the upper tool 5 may mirror the shape of the upper surface of the tool peripheral portion 32 of the lower tool 6. On the other hand, the tool central portion 42 and the tool peripheral portion 43 of the upper tool 5 delimit the active surface 5a which, when the portion 2a of the top film is located inside the chamber C of the packaging assembly 101, is configured to directly face and be active on the portion 2a of the top film 2. At the same time, the tool central portion 31 and the tool peripheral portion 32 of the lower tool 6 delimit an active surface 6a which, when the portion 1a of the bottom support 1 is located inside the chamber of the packaging assembly 101, is configured to directly face and support said portion 1a.

Moving now to a more detailed description of the mutually facing bottom side of the upper tool and top side of the upper tool, it is noted that the upper tool 5 further comprises an outer closing surface 5b surrounding the active surface 5a of the same upper tool 5, while the lower tool 6 further comprises an outer closing surface 6b surrounding the active surface 6a of the same lower tool 6.

Various alternatives of the closing surfaces are now described with reference to the attached figures.

In a first alternative, the outer closing surface 5b of the upper tool 5 may be defined by an outer portion (for example of flat conformation), integral with the tool peripheral portion 43 of the upper tool 5: as shown in figures 3-10, the outer closing surface 5b is positioned at, or in alignment with, the bottom surface of the outer abutting section 43b, and optionally also in alignment with the bottom surface of the inner abutting section 43a, of the upper tool 5. The outer closing surface 5b extends around and wholly encircles or delimits the bottom surface of tool peripheral portion 43 of the upper tool 5.

In this first alternative of figures 3-10, the lower tool 6 may comprise a sleeve 48 slidingly mounted outside the tool peripheral portion 32 and terminally defining the outer closing surface 6b of the lower tool 6, which may be for example of flat conformation; the sleeve 48 may be normally pushed in the position for example shown in figure 9 by the action of a spring device or by an actuator controlled by control unit 50, such that the outer portion 6b (when the tools are in the open configuration) is normally positioned at a level above the top surface of the outer abutting section 32b, and optionally also of the top surface of the inner abutting section 32a, of the lower tool 6. When the upper and lower tools 5 and 6 are moved to the closed condition (see figures 6 and 9A), the closing surface 5b and the closing surface 6b interact to define a peripheral closure and form the closed chamber C. Note the outer closing surface 6b extends around and wholly encircles or delimits the tool peripheral portion 32 of the lower tool 6 and faces the closing surface 5b of the upper tool 5 in order to form a tight closure therebetween, while still maintaining the inner abutting section 32a and the outer abutting section 32b of the lower tool apart respectively from the inner abutting section 43a and the outer abutting section of the 43b of the upper tool. An additional sealing body 80 (such as an annular gasket or an O-ring) may be interposed between the closing surface 5b of the upper tool 5 and the closing surface 6b of the lower tool 6. When the upper and lower tools 5, 6 are relatively moved by a further relative stroke to the sealing condition, the sleeve 48 is relatively lowered with respect to the lower tool 6 as shown in figures 7 and 8, such that the closing surface 6b (an thus also the closing surface 5b, if we exclude the minimum contribution provided by the film) are brought in substantial alignment with each other and with the top surface and the the inner abutting section 43a and the inner abutting section 32a cooperate in the formation of the sealing band 3, while the intermediate abutting section 43c and the intermediate abutting section 32c, thanks to their concave conformation, are configured to cause formation of said one or more hollow structures 4. The outer abutting section 43b of the upper tool and the outer abutting section 32b of the lower tool ensure a complete fluid-tight sealing of the package 200 and of each hollow structure 4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band 3.

Alternatively, as shown in figures 11-14, the outer closing surface 5b of the upper tool 5 may be defined by an outer side wall of the tool peripheral portion 43 of the upper tool 5 cooperating with an inner side wall of the lower tool 6. For example, the closing surface 5b may be defined at an inferiorly protruding part of the tool peripheral portion 43 extending towards the lower tool 6 (see again figures 11-14). In the embodiment shown in figures 11-14 therefore, the closing surface 5b of the upper tool 5 is transverse (in particular perpendicular) to the outer abutting section 43b of the tool peripheral portion 43 of the upper tool 5. On its turn, the outer closing surface 6b of the lower tool 6 of the example of figures 11-14 may be defined by an inner side wall, integral with the tool peripheral portion 32 of the lower tool 6, protruding with respect to the tool peripheral portion 32 towards the upper tool 5. In this example, the closing surface 6b of the lower tool 6 is defined by a surface which transversally emerges from the outer abutting section 32b of the tool peripheral portion 32 of the lower tool 6 and internally (and tightly) receives the closing surface 5b of the upper tool 5 (in figures 11-14 both surfaces 5b and 6b are vertical). Of course, the design of the surfaces 5b and 6b may be such that it is the lower tool closing surface 6b being defined on an outer side wall of the lower tool 6 and being tightly received inside a closing surface 5b on an inner side wall of the upper tool 5. Also in the example of figures 11-14, an additional sealing body 80 (such as an annular gasket or an O-ring) may be interposed between the closing surface 5b of the upper tool and the closing surface 6b of the lower tool. The closing surfaces 5b and 6b interact such that when the upper and lower tools are 5 and 6 are moved to the closed condition (see figure 12), the closing surface 5b and the closing surface 6b interact to define a peripheral closure and form the closed chamber C. Note the outer closing surface 6b extends around and wholly encircles or delimits the tool peripheral portion 32 of the lower tool 6 and faces the closing surface 5b of the upper tool in order to form a tight closure therebetween, while still maintaining the inner abutting section 32a and the outer abutting section 32b of the lower tool apart respectively from the inner abutting section 43a and the outer abutting section of the 43b of the upper tool. When the upper and lower tools are relatively moved by a further relative stroke to the sealing condition, the closing surface 6b continuous to cooperate with the closing surface 5b to keep the closed chamber closed, while the inner abutting section 43a and the inner abutting section 32a cooperate in the formation of the sealing band 3 and the intermediate abutting section 43c and the intermediate abutting section 32c, thanks to their concave conformation, cause formation of said one or more hollow structures 4. When the upper and lower tools reach the sealing condition, the outer abutting section 43b of the upper tool and the outer abutting section 32b of the lower tool ensure a complete fluid-tight sealing of the package 200 and of each hollow structure 4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band 3.

In a yet further alternative embodiment shown in figures 15-18, the upper tool 5 may comprise an inferiorly open case 47, externally surrounding the tool peripheral portion 43 and the tool central portion 42. The bottom of the case 47 exhibits a bottom peripheral surface (for example of flat conformation) facing the lower tool 6 and defining the closing surface 5b of the upper tool 5. In detail, the case 47 is movable with respect the tool peripheral portion 43 between:

- a retracted position, where the bottom peripheral surface of said case 47 is positioned radially outside the outer abutting section 43b of the tool peripheral portion 43 substantially aligned at the same level (height) of said outer abutting section 43b (figure 15),

- a protruding position, wherein the bottom peripheral surface of the case 47 axially protrudes with respect to the tool peripheral portion 43 towards the lower tool 6 (see figures 16 and 17) forming an annular closing surface 5b abutting against the lower tool closing surface 6b or pressing film material against the lower tool closing surface 6b.

In this latter embodiment, during the closed condition of the upper and lower tools, the case 47 is arranged in the protruding position with the closing surface 5b in close proximity to or in contact against the closing surface 6b of the lower tool 6 (see figures 18 and 19), in order to define the closed chamber C and, at the same time, allow the active surfaces 5a, 6a to remain separate. During the passage of the upper and lower tools from the closed to the sealing condition, the case 47 relatively moves from the protruding back to the retracted position allowing the active surfaces 5a, 6a of the upper and lower tools to define the sealing band 3 and the hollow structure(s) 4. In the example of figures 15-18, the outer closing surface 6b of the lower tool 6 may be defined by an outer portion (for example of flat conformation), integral with the tool peripheral portion 32 of the lower tool 6; the outer surface 6b is positioned at, or in alignment with, the top surface of the outer abutting section 32b, and optionally also with the top surface of the inner abutting section 32a, of the lower tool 6. The outer closing surface 6b extends around and wholly encircles or delimits the tool peripheral portion 32 of the lower tool 6 and faces the closing surface 5b of the upper tool in order to form a tight closure therebetween, when the tools 5 and 6 are brought in the closed condition, with the case in the protruding position (figure 17). Also in this example additional sealing body 80 (such as an annular gasket or an O-ring) may be interposed between the closing surface 5b of the upper tool and the closing surface 6b of the lower tool. When the tools 5 and 6 in the closed condition (see figure 17), outer closing surface 6b extends around and wholly encircles or delimits the tool peripheral portion 32 of the lower tool 6 and faces the closing surface 5b of the upper tool in order to form a tight closure therebetween, while still maintaining the inner abutting section 32a and the outer abutting section 32b of the lower tool apart respectively from the inner abutting section 43a and the outer abutting section of the 43b of the upper tool. It is noted that with the packaging station in the closed condition of figures 16 and 17, the access 16 is formed by a channel formed by the case 47 or between the case 47 and the upper tool peripheral portion 43: the access may be connected to the gas source 15 or to the suction source 13 to respectively inject or withdraw gas from the chamber C. When the upper and lower tools are relatively moved by a further relative stroke to the sealing condition, the case 47 moves to its retracted position (figure 18), the closing surface 6b continuous to cooperate with the closing surface 5b to keep the closed chamber closed, while the inner abutting section 43a and the inner abutting section 32a cooperate in the formation of the sealing band 3 and the intermediate abutting section 43c and the intermediate abutting section 32c, thanks to their concave conformation, cause formation of said one or more hollow structures 4. When the upper and lower tools reach the sealing condition, the outer abutting section 43b of the upper tool and the outer abutting section 32b of the lower tool ensure a complete fluid-tight sealing of the package 200 and of each hollow structure 4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band 3.

In a variant of the example of figures 15-18, the case 47 may cooperate with the radially external side wall of the lower tool 6 and the closing surface 6b be defined at the superior part of the case 47 and extend transversally (in particular perpendicular) to the outer abutting section 32b of the tool peripheral portion 32 of the lower tool 6. In this case, the position of the case 47 would be overturned compared to what is shown in figures 15-18 and the upper tool 5 would include an outer portion (for example of flat conformation), integral with the tool peripheral portion 43 of the upper tool 5. Operation would be similar to what just described with reference to figures 15- 18.

Continuing in the detailed description of the upper and lower tools, it is noted that, as shown in the enclosed figures, the active surface 5a of the upper tool 5 comprises a plurality of first holes 44 in fluid communication with at least one suction source 13 via first channels 44a. The suction source 13 is configured to withdraw gas from said first holes and cause the portion 2a of the top film 2 to adhere to the active surface 5a of the upper tool 5. In detail, the suction source 13 is configured to withdraw gas from the closed chamber C, during the closed condition of the upper and lower tool in order to cause the portion 2a of the top film to intimately adhere to the active surface 5a.The suction source 13 comprises at least one vacuum pump 13a and at least one evacuation line 13b connecting the inside of said chamber C to the vacuum pump via the first holes 44. The suction source 13 may comprise a valve 13c active on said evacuation line 13b and configured to regulate the gas flow passage through said line. The control unit 50 controls the vacuum pump 13a and/or the valve 13c to withdraw gas from the closed chamber C via said first holes 44.

The tool peripheral portion 43 and the tool central portion 42 of the upper tool 5 are made, at least partially, in a heat conductive material: this allows to heat the upper tool thereby allowing the portion 2a of the top film 2 to be correctly sealed to the portion 1a of the bottom support 1 during the sealing condition. In detail, the upper tool 5 comprises at least one heater, for example comprising a resistive heater or an infrared heater or a hot fluid heater or a heater of other nature, configured for heating the active surface 5a of the upper tool 5 to allow heating of the portions 2a of the top film 2 dedicated to be directly sealed with the portion 1a of the bottom support 1. In detail, the heater (for example in the form of an electric resistor part of an electric heating circuit) is arranged at least at the tool peripheral portion 43 of the upper tool 5 allowing this latter to form the sealing band 3 and the hollow structure 4. The heater (again for example in the form of an electric resistor) may be also located at the active surface 5a of the upper tool 5 directly facing the product P arranged on the portion 1a of the bottom support 1; in other words, the heater may be arranged at the tool central portion 42 of the upper tool 5 allowing the portion 2a of the top film to warm and get deformable. In particular, when the portion 2a of the top film 2 is put in contact to the active surface 5a of the upper tool by means of the suction source 13, the heater causes the portion 2a to heat up to a temperature sufficient to allow the same portion 2a to heat bond (heat-seal) the portion 1 a of the bottom support 1.

Similar to the upper tool, also the active surface 6a of the lower tool 6 may comprise a plurality of second holes 33 in fluid communication, via second channels 33a, with the same or another suction source 13: although indicated with same reference number, suction source 13 may include a single suction source active on the first and second holes or separate suction sources 13, wherein at least one active on the first holes of the upper tool and at least another one active on the second holes of the bottom tool. The suction source 13 active on the second holes 33 is configured to withdrawn gas from said second holes to cause the portion 1a of the bottom support 1 to adhere the active surface 6a of the lower tool 6. In detail, the suction source 13 is configured to withdrawn gas from the closed chamber C, at least during the closed condition of the upper and lower tools 5 and 6, in order to pull the portion 1a of the bottom support in adhesion to the active surface 6a. The control unit 50 may for example control vacuum pump 13a and/or valve 13c of the suction source 13 active on the second holes to withdraw gas from said second holes 33.

According to a further aspect, the tool peripheral portion 32 and, in certain cases, the tool central portion 31 of the lower tool 6 are made, at least partially, in a heat conductive material. This allows to heat the lower tool thereby allowing the portion 1a of the bottom support 1 to be correctly sealed to the portion 2a of the top film during the sealing condition. In detail, the lower tool 6 comprises at least one heater, for example comprising a resistive heater or an infrared heater or a hot fluid heater or a heater of other nature, configured for heating the active surface 6a of the lower tool to heat the portions 1a and to allow heat sealing one or more parts of said portions 1a, 2a of the bottom and top film, during the sealing condition. In particular, the heater may be located at the active surface 6a of the lower tool 6 to allow heating of the portions 1 a of the bottom support 1 dedicated to be directly sealed with the portion 2a of the top film 2; in detail, the heater is arranged at least at the tool peripheral portion 32 of the lower tool 6 allowing this latter to define, in cooperation with the tool peripheral portion 43 of the upper tool 5, the sealing band 3 and the hollow structure 4.

According to a further aspect, the lower tool may comprise, preferably at a central portion 31 thereof, an insulating body 31a at least partially made in a heat insulating material (for example the insulating body may be a plastic insert as shown in the figures) such that heating of the lower tool by the respective heater does not excessively affect the insulating body and thus the product above it; the insulating body 31a is in fact configured to receive the part of the film portion 1a above which the product will rest, thereby avoiding excessive warming of products during packaging. According to a further aspect, the insulating body 31 a may be cooled: for example a cooling circuit 31b (schematically represented in the figures) may be positioned adjacent to the insulating body 31a or a part of the cooling circuit may go through the insulating body to keep the insulating body relatively cold. The cooling circuit may circulate a cooling fluid, for example water, and keep the insulating body (or at least the surface of the insulating body destined to contact the film portion 1a at a temperature below a set temperature, for example below 30 °C .

After the above description of the structure upper and lower tools 5, 6, here it is provided an indication about how the tools may cooperate together and with the other parts of the apparatus 100.

As mentioned above, the upper and lower tools 5, 6 are movable at least between the open condition, the closed condition and the sealing condition. In detail, at the open condition, the outer closing surfaces 5b, 6b and the active surfaces 5a, 6a of the upper and lower tool 5, 6 are spaced from each other in order to allow the portions 1 a, 2a to be placed between the active surfaces of the upper and lower tools 5, 6; during the open condition the chamber C is open and the active surfaces 5a, 6a are generally at their maximum distance from each other. When the upper and lower tools are relatively approached (under the control of unit 50), they initially reach the closed condition. With the tools in the closed condition, the upper and lower tools are positioned such that:

- the active surfaces 5a, 6a of the upper and lower tools 5, 6 are still spaced from each other,

- the outer closing surfaces 5b, 6b are proximate to each other: in particular, the closing surface 5b of the upper tool 5 tightly abuts against the closing surface 6b of the lower tool 6 (optionally with interposition of the film portions 1a, 2a) to hermetically close said packaging chamber C with respect to an atmosphere outside the apparatus; at said closure surfaces 5b, 6b, sealing body 80 (such as an annular gasket or an 0- ring or other element) is squeezed between the surfaces 5b and 6b thereby facilitating a gas tight closure of the chamber C.

At least during the closed condition, the at least one suction source 13 is activated in order to withdraw gas from the first and second holes, allowing the portion 1a of the bottom support to adhere to the active surface 6a of the lower tool 6 and allowing the portion 2a of the top film 2 to adhere to the active surface 5a of the upper tool 5. It should be noted that, the suction source 13 may be activated also while the upper and lower tools 5, 6 are still in the open condition; in this case, the portions 1a, 2a have to be arranged in proximity of the active surface 6a, 5a, respectively, allowing the second and first holes to pull said portions in contact with the respective active surfaces (see figures 4, 11 and 15). Thanks to the suction source 13 and the first and second holes 44, 33, the upper and lower tools 5, 6 are configured to maintain said portion 2a of the top film 2 and said portion 1a of the bottom support 1 separated the one from the other, at least during the closed condition.

The control unit 50 may then move the upper and lower tools to the sealing condition. During the sealing condition (see figures 7, 8, 10, 13, 14, 18 and 19) at least part of the upper tool 5 and part of the lower tool 6 become very close and lead to contact said portions 1 a, 2a of the bottom support 1 and of the top film 2 in order to seal said portions and form a package 200 containing the product. In greater detail, the upper and lower tools 5, 6, in said sealing condition, are configured to seal the portion 1a of the bottom support 1 to the portion 2a of the top film 2 along a sealing band 3 circumscribing the product P to sealingly house the product P in a volume V between said portion 2a of the top film 2 and said portion 1 a of the bottom support 1. Furthermore, the upper and lower tool, in said sealing condition are configured to form one or more hollow structures 4 by sealing a part of said portion 2a of the top film 2 to a part of said portion 1a of the bottom support 1 at one or more selected seal zones; as shown in figure 20, the hollow structure 4 extends around and wholly encircles said sealing band 3. In detail, during the sealing condition, the tool peripheral portion 32 of the lower tool 6 approaches and almost contacts the tool peripheral portion 43 of the upper tool 5 (figures 7, 8, 10, 13, 14, 18 and 19); moreover, during the sealing condition the components of the packaging assembly are configured to interact as follows:

- the inner abutting section 32a of the lower tool faces and is vertically aligned with the inner abutting section 43a of the upper tool 5; in particular, the inner abutting section 32a of the lower tool 6 directly contacts the portion 1a of the bottom support 1, while said inner abutting section 43a of the upper tool 5 directly contacts the portion 2a of the top film 2: the inner abutting section 32a and the inner abutting section cooperate to bring portion 1a of the bottom film in contact with portion 2a of the top film at selected areas in particular forming the sealing band 3 which sealingly joins the portions 1a and 2a tightly insulating the product inside the volume V;

- the intermediate abutting section 32c of the lower tool 6 faces the intermediate abutting section 43c of the upper tool 5; in particular, the intermediate abutting section 32c of the lower tool 6 directly contacts the portion 1a of the bottom support 1 while the intermediate abutting section 43c of the upper tool 5 directly contacts the portion 2a of the top film 2: the intermediate abutting sections 32c, 43c, during the sealing condition, face each other and, thanks to their concave shape and vertical alignment are configured to form said one or more hollow structures 4 adjacent to, and radially external from, the sealing band 3;

- the outer abutting section 32b of the lower tool faces the outer abutting section 43b of the upper tool 5; in particular, the outer abutting section 32b of the lower tool 6, which directly contacts the portion 1a of the bottom support 1, and the outer abutting section 43b, which directly contacts the portion 2a of the top film 2, bring said portion 1a in contact with the portion 2a of the top film 2; moreover, the outer abutting sections 32b, 43b respectively of the lower and upper tool, during the sealing condition, face each other and are configured to define an outer sealing band 30 which fluid-tightly seals the package 200; as schematically shown in figure 20, the one or more hollow structures 4 formed is interposed between the sealing band 3 and the outer sealing band 30.

In order to relatively move the upper and lower tools 5, 6 between the above described open condition, closed condition and sealing condition, the apparatus 100 has at least one main actuator 60 active on at least one of said upper and lower tool 5, 6 and controlled by the control unit 50. In practice, the main actuator 60 may be any kind of electric, pneumatic or hydraulic actuator configured for lifting and lowering one or both tools 5, 6 along a direction transverse (see e.g. the vertical direction identified with reference A2 in figures 1 and 2) to said horizontal direction A1 .

Furthermore, the apparatus 100 comprises at least a discharge conveyor 70 disposed downstream the packaging assembly 101 with respect to said horizontal direction A1. Discharge conveyor 70 is configured for displacing the formed package 200 towards a deposit station (not shown) placed downstream the packaging assembly 101. The conveyor 70 is controlled by the control unit 50 to be either continuously active or at least active during the open condition of the apparatus 100: a pick-up mechanism (also not shown) may be present between the packaging station 101 and the discharge conveyor to bring the formed package 200 from the closed chamber C onto the discharge conveyor 70 during the open condition of the upper and lower tools 5 and 6 following the sealing condition once the package 200 is formed.

In greater detail, the control unit 50 is configured to command the packaging assembly 101 to execute the following steps:

- positioning the upper and lower tools 5, 6 in the open condition;

- then positioning the upper and lower tools 5, 6 in the closed condition, with the portion 1 a of the bottom support 1, the product P and the portion 2a of the top film 2 received inside the closed chamber C;

- then sealing the portion 1 a of the bottom support 1 to the portion 2a of the top film 2 along the sealing band 3 circumscribing the product P to sealingly house the product P in the volume V between said portion 2a of the top film 2 and said portion 1 a of the bottom support 1 : the sealing step takes place moving the upper and lower tools 5, 6 as described above from the closed condition to the sealing condition whereby the tool peripheral portions 32 and 43 respectively of the lower and upper tools bring portions 1a, 2a in mutual contact along an area forming sealing band; of course, the control unit also commands the heater to properly heat up the at least one or both the peripheral portions 32 and 43 to reach the temperature needed for the heat bonding and formation of the sealing band 3;

- forming the one or more hollow structures 4 by sealing a part of said portion 2a of the top film 2 to a part of said portion 1 a of the bottom support 1 at one or more selected seal zones; this step of forming the hollow structure 4 is preferably executed by moving the upper and lower tools from the closed condition to the sealing condition, simultaneously with the formation of the sealing band 3;

- before the step of forming the one or more hollow structures 4 (and preferably before both the steps of formation of the sealing band 3 and of formation of the one or more hollow structures 4), and after formation of the closed chamber C, maintaining at least the peripheral part of portion 2a of the top film 2 separate and at a distance from the underlying peripheral part of portion 1a of the bottom support 1; optionally, as shown in the attached figures before the steps of forming the one or more hollow structures 4and of forming the sealing band 3, the control unit controls the packaging assembly 101 to keep the entire portion 2a spaced apart from the underlying portion 1a (see figures 5, 12 and 17); this step allows to inflate gas into the chamber with therefore the possibility to form the desired gas conditions inside the volume V and inside the hollow structure or structures 4, as it will be further explained herein below. As just described, the upper and lower tools 5, 6, are configured to maintain the portions 1 a and 2a (or parts thereof) separate thanks to the ability of positioning the active surfaces 5a, 6a mutually apart and thanks to the action of the suction source 13 which is in fluid communication with the first and second holes 33, 44 of the lower and upper tools, respectively. In particular, the control unit 50 is also connected to the suction source 13 and configured to (after commanding the packaging station in the closed condition of the upper and lower tools 5, 6, and at least during said closed condition before the sealing step takes place) command the suction source 13 to withdrawn gas from the first and second plurality of holes 44, 33 in order to separate the portion 2a of the top film 2 and the portion 1a of the bottom support 1 by adhering said portion 2a of the top film 2 to the active surface 5a of the upper tool 5 and by adhering said portion 1a of the bottom support 1 to the active surface 6a of the lower tool 6.

In this way, following the passage of the upper and lower tools from the closed to the sealing condition, the tool peripheral portions 43, 32 of the upper and lower tools 5, 6 allow to form one or more hollow structures 4.

As shown in the enclosed figures, the packaging apparatus 100 may also comprise at least one gas source 15 (figures 4-8 and 11-17) in fluid communication with at least one access 16 defined on at least one between the upper tool 5 and the lower tool 6. The access 16 is configured to put in fluid communication the gas source 15 with the closed chamber C and/or the volume V, at least during the closed condition of the upper tool 5 and the lower tool 6 of the packaging assembly 101. The gas source 15 comprises an inflation pump 15a and an inflation line 15b connecting said pump 15a with the access 16. Furthermore, the gas source 15 may comprise a regulating valve 15c active on the inflation line 15b and configured to regulate the flow passage through said line 15b. The control unit 50 is connected with the gas source 15 and it is configured to (after commanding the packaging station in the closed condition of the upper and lower tools 5, 6, and at least during said closed condition before the sealing step takes place) command the gas source 15 to inflate gas into the closed chamber C through the access 16.

The control unit 50 is configured to command the gas source 15 (e.g. acting on the inflation pump 15a and/or on the regulating valve 15c) for inflating gas into the closed chamber C through the access 16 at least during the closed condition of the upper and lower tools and during the above described step of withdrawing of gas executed by the suction source 13 via the first and second plurality of holes 44, 33; in this way, the apparatus ensures that, during the passage between the closed condition and the sealing condition, a predetermined gas pressure or a predetermined quantity of gas be present in the closed chamber C thereby facilitating the formation of one or more hollow structures 4 housing gas at a pressure above the atmospheric pressure.

In particular, according to a possible non-limiting variant and as shown in the enclosed figures, the packaging apparatus 100 may comprise at least one hollow element 10, e.g. a hollow needle, operative inside a seat 14 defined on at least one between the upper and lower tools 5, 6. The hollow element 10 is configured to pierce at least one of the portion of the top film 2 and the portion of the bottom support 1 and to be inserted at least partially inside the volume V: the hollow element 10 is further configured to inject into and/or withdrawn gas from the volume V. In the enclosed figures, the hollow element 10 is supported, in a non-limiting way, by the lower tool 6; it is not excluded that the hollow element 10 be associated to the upper tool 5 or that at least one hollow element 10 may be provided for each of said lower and upper tools.

According to a currently preferred variant, the hollow element is carried by the lower tool 6 and is configured to pierce the portion 1a of the bottom support. In particular, as shown in the figures, the hollow element 10 may be operative in correspondence the radial periphery of the lower tool central zone 31, close to the inner abutting section 32a of the tool peripheral portion 32: this allows the hollow element(s) 10, when operated, to pierce the bottom support 1 far from the area where the product P is positioned, thereby allowing (when the package is then formed) to have the holes formed by the hollow element(s) 10 in the bottom support 1 closed by the draping down of the top film portion 2a on the product and on the bottom support portion 1a not covered by the product. The hollow element 10 is relatively movable with respect to the upper and/or the lower tool 5, 6 at least between:

- a retracted position, where the hollow element 10 is spaced from the portion 1a of the bottom support 1 and spaced from the portion 2a of the top film 2 (figures 3-5, 8-11 and 14-16), and

- an advanced position, where the hollow element 10 pierces at least one between the portion 1 a of the bottom support 1 and the portion 2a of the top film 2; the hollow element 10, in the advanced position, has crossed the thickness of the bottom support (or of the top film) and has a terminal portion located inside the volume V delimited by the portions 1a, 2a of the bottom support 1 and the top film 2 (figures 6-7, 12-13 and 17-19).

The hollow element 10 is configured to be put in fluid communication with the gas source 15. The control unit 50 is connected to the hollow element 10 and to the gas source 15; the control unit 50 is also configured to control operation of the gas source 15 and command the hollow element 10 (acting on an appropriate actuator) to move between the retracted and the advanced position. In particular, the control unit 50 is configured to define an inflating cycle comprising:

- command the hollow element(s) 10 to move from the retracted position to the advanced position at least during the closed condition of the upper and lower tools 5, 6,

- with the hollow element(s) in the advanced position, command the gas source 15 to inflate gas inside the volume V through said hollow element(s) 10.

As mentioned above, the packaging apparatus 100 may also be adapted for forming modified atmosphere packaging: in this case, the packaging assembly 101 may be configured to create inside volume V defined between said bottom support 1 and top film 2 a modified gas atmosphere. The hollow element 10 may thus be used to inject inside the volume V a specific gas in order to define said modified atmosphere packaging. The control unit 50 may also be configured to control the gas source 15 in order to regulate the composition of the gas stream injected into the packaging chamber C and thus control the composition of the modified atmosphere inside said chamber C and/or inside the volume V. The gas mixtures injected into the packaging chamber to generate a modified atmosphere may vary depending upon the nature of the product P.

As shown in the enclosed figures, the hollow element 10 may also be in fluid communication with the suction source 13 (e.g. it could be configured to draw gas from the chamber C and volume V through the first and/or second holes 44, 33) for withdrawing gas from the volume V for defining a vacuum skin package surrounded by said one or more hollow structures (see figure 20). The control unit 50 is operative on the actuator connected to the hollow element(s) 10 and on the suction source 13. The control unit is configured to control the operations of the suction source 13 and - as described above - command the hollow element(s) in the retracted and in the advanced position. The control unit 50 may in particular be configured to:

- command the hollow element 10 to move from the retracted position to the advanced position at least during the sealing condition of the upper and lower tools 5, 6,

- with the hollow element(s) in the advanced position and with the tools in the sealing condition, command the suction source 13 to withdraw gas from the volume V through said hollow element 10.

The control unit may also be configured to execute the following further steps, after the step of withdrawing of gas from the volume V:

- command the hollow element 10 to move from the advanced position back to the retracted position,

- with the hollow element(s) in the retracted position, command the suction source 13 to interrupt withdrawal of gas from the volume V,

- following the interruption of withdrawal of gas from the volume V or sometime before such interruption, command the gas source 13 to also interrupt the withdrawal of gas from the first and/or second plurality of holes in order to allow the portions 1a, 2a of the bottom support 1 and of the top film 2 to wrap the product P and intimately adhere one against the other in correspondence of those areas of portions 1a and 2a not in contact with the product; note that in this phase any hole formed during piercing by the hollow element(s) is sealingly closed by the sealing attachment of the portions 1a and 2a with each other.

With the step of withdrawing gas from the volume V, the apparatus 100 is thus able to form a vacuum skin package.

Note that also when forming the vacuum skin packages, the hollow structure(s) 4 are formed preferably by inflating gas into the closed chamber. In particular, the control unit 50 may be configured to execute first the inflating cycle described above and then a suction cycle comprising:

- commanding the upper and lower tools 5, 6 to move from the closed condition to the sealing condition,

- move the hollow element(s) 10 to the advanced position and with the upper and lower tools in the sealing condition, commanding the gas source 15 to interrupt the inflation of gas into the volume V,

- maintaining the hollow element(s) 10 in the advanced position and the upper and lower tools in the sealing condition, commanding the suction source 13 to withdraw gas from the volume V through said hollow element(s) 10.

Then, after the suction cycle described above, the control unit may be configured to execute the following additional steps:

- commanding the hollow element(s) 10 to move from the advanced position back to the retracted position,

- commanding the suction source 13, with the hollow element 10 in the retracted position, to interrupt the withdrawal of gas from the volume V,

- commanding the suction source 13, following the interruption of withdrawal of gas from the volume V, to interrupt the withdrawal of gas from the chamber C or volume V via the first and/or second plurality of holes in order to allow the portions 1a, 2a of the bottom support 1 and of the top film 2 to wrap the product P and intimately adhere one against the other in correspondence of those areas of portions 1 a and 2a not in contact with the product; note that in this phase any hole formed during piercing by the hollow element(s) is sealingly closed by the sealing attachment of the portions 1a and 2a with each other.

Although the apparatus 100 may have one or both the suction source 13 and the gas source 15, it is to be understood that the control unit 50 of the apparatus 100 may also be configured to tightly engage the portion 2a of the top film 2 to the portion 1a of the bottom support 1 without activating the suction source or the gas source and thus leaving a normal environment atmosphere within the package.

Subsequently to the formation of the package 200, the control unit 50 is configured to command the upper and lower tools 5, 6 in the open condition to allow the package to be extracted from the packaging assembly 101 , and new portions 1a, 2a with a new product P to be positioned inside the open chamber C.

Packaging process

The present invention further concerns a process of packaging a product P. The process described below uses the packaging apparatus 100 disclosed above and/or according to enclosed claims. The process takes place under control of control unit 50 and achieves a process of packaging a product P between a bottom support 1 (e.g. in form of a film sheet having substantially the same structure of the top film 2 or in form of a tray) and a top film 2. In this case the described process allows making a skin packaging of the product. In any case the apparatus 100 is also capable of packaging products P under modified atmosphere. Moreover, the apparatus 100 may be used for applying the top film 2 to a bottom support 1 and thus form packaging under normal ambient atmosphere.

The packaging process comprises a step of supplying, at the same time, the bottom support 1 from the bottom support supply assembly 103 and the top film 2 from the top film supply assembly 102 such that one or more bottom support portions 1a and one or more top film portions 2a reach the packaging assembly 101 while the packaging assembly is maintained in the open condition. As described above, the bottom support and the top film may be in the form of a continuous film or may comprise a plurality of separate discrete portions. The portions 1a, 2a of the bottom support 1 and of the top film 2 are positioned inside the packaging assembly in open condition with the upper and lower tools 5, 6 defining said chamber C, which at this point is still open. The positioning step of said portions 1a, 2a may be done automatically by the control unit 50 acting on the bottom support supply assembly 103 and the top film supply assembly 102, or acting on the transfer device 108 of the portions 1a and the transport device 110 of the portions 2a. The process further comprise a step of loading at least a product P on the portion 1a of the bottom support 1 by means of a product loading station 111 which may be operative upstream the packaging assembly (see figure 1) so that the product P might be positioned on the portion 1a outside the packaging assembly 101 or which may be located at the packaging assembly 101 so that the product P might be positioned on the portion 1a already arranged inside the packaging assembly 101.

Following positioning of portions 1a, 2a and of product P inside the packaging assembly 101, the process provides for a step of forming the closed chamber C. The closed chamber C at this point of the process therefore houses: the portion 1a of the bottom support 1, the product P above said portion 1a of the bottom support 1 , and a portion 2a of the top film 2 above said product P and said portion 1 a of the bottom support 1 . In detail, the closed chamber C is defined by moving the upper and lower tools 5, 6 from the open condition to the closed condition, as described above.

With the mentioned components, namely said portion 1 a of the bottom support 1, said product P, said portion 2a of the top film 2 located inside the closed chamber C, and with the upper and lower tools in the closed condition, the active surfaces 5a, 6a of the upper and lower tools 5, 6 are spaced from each other while the outer closing surfaces 5b, 6b of the upper and lower tools are proximate to each other in order to form the closed chamber C.

During the closed condition of the upper and lower tools, said portion 2a of the top film 2 and said portion 1a of the bottom support 1 are maintained separate at a distance the one from the other; in particular, at least the part of said portion 2a of the top film 2 and the part of said portion 1 a of the bottom support 1 , which are destined to form the one or more hollow structures 4 are maintained separate at a distance the one from the other. In the examples shown the entirety of portion 2a of the top film 2 and the entirety of portion 1a of the bottom support 1 are maintained separate at a distance the one from the other. This may be achieved by adhering the portion 2a of the top film 2 to the active surface 5a of the upper tool 5 and by adhering the portion 1a of the bottom support 1 to the active surface 6a of the lower tool 6. In detail, adhering the portion 2a of the top film 2 to the lower active surface 5a of the upper tool 5 is achieved by withdrawing gas through said first holes 44 by means of said suction source 13 while adhering the portion 1a of the bottom support 1 to the active surface 6a of the lower tool 6 is achieved by withdrawing gas through said second holes 33, by means od said suction source 13.

During the closed condition of the upper and lower tools 5, 6 and while portions 1a, 2a adhere to the respective active surfaces 6a, 5a, the process provides for inflating a gas into the closed chamber C between said portion 2a of the top film 2 and said portion 1a of the bottom support 1. In particular, the step of inflating a gas is executed while:

- said portion 1a of the bottom support 1, said product P, and said portion 2a of the top film 2 located inside the closed chamber C; and - said portion 2a of the top film 2 and said portion 1a of the bottom support 1 are maintained separated at a distance the one from the other.

Always during the closed condition of the upper and lower tools 5, 6 and during the adhesion of the portions 1a, 2a to the respective active surfaces 6a, 5a, the process may provide a heating of the portions 1a of the bottom support 1 and/or of the portion 2a of the top film 2 allowing softening of said portions 1a, 2a in order to promote a correct sealing of portion 1a with portion 2a during the sealing step described below.

Subsequently, the process comprises the following further steps:

- sealing the portion 1 a of the bottom support 1 to the portion 2a of the top film 2 along a sealing band 3 circumscribing the product P to sealingly house the product in a volume V between said portion 2a of the top film 2 and said portion 1a of the bottom support 1; and

- forming one or more hollow structures 4 by sealing a part of said portion 2a of the top film 2 to a peripheral part of said portion 1 a of the bottom support 1 at one or more selected seal zones; the step of forming one or more hollow structures 4 comprises forming at least one hollow structure extending around and wholly encircling said sealing band 3.

The sealing step comprises a relative displacement of the upper tool 5 and of the lower tool 6 from the closed condition to the sealing condition, where at least part of the active surfaces 5a, 6a of the upper and lower tool 5, 6 are approached to each other and made proximate, leading to a mutual contact between the portions 1a and 2a respectively of the bottom support 1 and of the top film 2, thereby forming the sealing band 3 and the hollow structure(s) 4.

In detail, before forming the one or more hollow structures 4, at least the part of said portion 2a of the top film 2 and the part of said portion 1a of the bottom support 1, destined to form said one or more hollow structures 4, are maintained separate at a distance the one from the other. In particular, the part of the portion 1 a of the bottom support 1 destined to cooperate in the formation of the hollow structure(s) is a peripheral portion 12 surrounding a central portion 11 of the same portion 1 a of the bottom support 1 ; similarly, the part of the portion 2a of the top film 2 destined to cooperate in the formation of the hollow structure(s) is a peripheral portion 23 surrounding a central portion 22 of the same portion 2a of the top film 2; note that before said step of forming the one or more hollow structures 4, the portion 2a of the top film 2 and the portion 1a of the bottom support 1 are maintained separated the one from the other, and in vertical alignment, in correspondence of said respective peripheral portions 12, 23 destined to form said one or more hollow structures 4 (and optionally also in correspondence of the central portions of the bottom support and the top film).

As described above, in the closed condition of the upper and lower tools, the portion 1a of the bottom support 1 and the portion 2a of the top film are maintained separated by adhering said portions to the respective active surfaces of the lower and upper tools. In particular, during the adhering step of the portion 2a of the top film 2 to the active surface 5a of the upper tool 5, at least the peripheral portion 23 of the top film 2 adheres the active surface 5a of the upper tool 5. At the same time, during the adhering step of the portion 1 a of the bottom support 1 to the active surface 6a of the lower tool 6, at least the peripheral portion 12 of the bottom support 1 adheres the active surface 6a of the lower tool 6.

As shown in figures 4-7, 11-13, 15-18, the central portion 22 of the top film 2, during the adhering step, is directly in contact with the upper tool central portion 42, while the peripheral portion 23 of the top film 2 is directly in contact with the tool peripheral portion 43 of the same upper tool. In particular, the peripheral portion 23 of the portion 2a of the top film 2 comprises at least:

- an inner tract 23a radially extending from the central portion 22 of the top film 2; the inner tract 23a, during the adhering step, faces and directly contacts the inner abutting section 43a of the tool peripheral portion 43 of the upper tool 5;

- a central tract 23b radially extending from the inner tract 23a of the top film 2, away from the central portion 22 of the same top film 2, the inner tract 23a being interposed between the central portion 22 and the central tract 23b of the top film 2; the central tract 23b, during the adhering step, faces and directly contacts the intermediate abutting section 43b of the tool peripheral portion 43 of the upper tool 5;

- an outer tract 23c radially from the central tract 23b of the top film 2: the central tract 23b being interposed between the inner tract 23a and the outer tract 23c of the peripheral portion 23 of the top film 2; the outer tract 23c, during the adhering step, faces and directly contacts the outer abutting section 43c of the tool peripheral portion 43 of the upper tool 5.

On the other hand, again as shown in figures 4-7, 11-13, 15-18, the central portion 11 of the bottom support 1, during the adhering step, is directly in contact with the tool central portion 31 of the lower tool while the peripheral portion 22 of the bottom support 1 is directly in contact with the tool peripheral portion 32 of the same lower tool 6. The peripheral portion 12 of the bottom support 1 comprises at least:

- an inner tract 12a extending from the central portion 11 of the bottom support 1; the inner tract 12a, during the adhering step, faces and directly contacts the inner abutting section 32a of the tool peripheral portion 32 of the lower tool 6;

- a central tract 12b protruding from the inner tract 12a of the bottom support 1, away from the central portion 11 of the same bottom support 1 : the inner tract 12a of the bottom support 1 being interposed between the central portion 11 and the central tract 12b of the bottom support 1; the central tract 12b, during the adhering step, faces and directly contacts the intermediate abutting section 32b of the tool peripheral portion 32 of the lower tool 6;

- an outer tract 12c protruding from the central tract 12b of the bottom support 1 : the central tract 12b being interposed between the inner tract 12a and the outer tract 12c of the peripheral portion 12 of the bottom support 1 ; the outer tract 12c, during the adhering step, faces and directly contacts the outer abutting section 32c of the tool peripheral portion 32 of the lower tool 6.

Exclusively during the sealing of the portion 1a of the bottom support 1 with the portion 2a of the top film 2, the inner tract 12a of the portion 1a is brought in contact and heat sealed to the inner tract 23a of the portion 2a and the outer tract 12c of the portion 1a is brought in contact and heat sealed to the outer tract 23c of the portions 2a. Following the sealing of the portion 1a of the bottom support 1 with the portion 2a of the top film 2 as just described, the central tract 12b of the peripheral portion 12 of the bottom support 1 and the central tract 23b of the peripheral portion 23 of the top film 2 form the one or more hollow structures 4 (figure 20).

Moreover, when gas inflating is practiced between the portions 1a, 2a of the bottom support 1 and the top film 2 and thanks to the adhesion of said portions 1 a, 2a to the respective active surfaces 5a, 6a of the upper and lower tools 5, 6, the process may define one or more hollow structures 4 with the desired quantity of gas inside and thus with the desired stiffness. The step of sealing the portion 1a of the bottom support 1 to the portion 2a of the top film 2 along said sealing band 3, and said step of forming one or more hollow structures 4 are for example executed simultaneously.

The process may further comprise a step of creating an access to said volume V by insertion of at least one hollow element 10, optionally a hollow needle, through one of the portion 2a of the top film portion 2 and the portion 1a of the bottom support 1 such that the hollow element 10 is at least partially inserted into the volume V. The step of creating an access to the volume V comprises a sub-step of piercing at least one between the central portion 11 of the bottom support 1 and the central portion 22 of the top film 2 with the hollow element 10 in order to pass through said at least one central portion and positioning a terminal portion of the hollow element 10 inside the volume V. In particular, the hollow element is inserted inside the volume V during the adhering phase of the portions of the bottom support 1 and of the top film 2 to the active surface of the lower and upper tool 5, 6 respectively. The gas inflating step may be executed through the inserted hollow element(s) 10 which may be put in fluid communication with the gas source 15. Alternatively, with reference to the example of figures 15-18, the gas inflating step may take place using the access or channel 16 formed by the case 47 or between the case 47 and the upper tool peripheral portion 43: the access may be connected to the gas source 15 to inject gas into the chamber C.

The process, following the sealing step, may comprises a step of withdrawing gas from said volume V to let the portion 2a of the top film 2 portion to adhere to the product P and to the portion 1a of the bottom support 1. In particular, the step of withdrawing gas follows the sealing step and may comprise inserting the hollow element 10, optionally a hollow needle, through one of the portion 2a of the top film portion 2 and the portion 1a of the bottom support 1 such that the hollow element 10 is at least partially inserted into the volume V and creates a fluid communication between the volume and the suction source 13 positioned outside the volume V: operating the suction source 13 allows to withdraw gas from the volume V through said hollow element 10 and (once the portions 1 a and 2a have been released from the respective active surfaces 6a and 5a) causes formation of a vacuum skin package hosting the product, delimited by the sealing band 3 and surrounded by the hollow element(s) 4.

In fact, before or during said step of withdrawing gas from said volume V, the first holes 44, optionally both said first and second holes 44, 33, are either vented to external atmosphere or supplied with gas at a pressure higher than atmospheric pressure to release the portion 2a of the top film 2 from the active surface 5a of the upper tool 5 and, optionally, to release the portion 1a of the bottom support 1 from the active surface 6a of the lower tool 6

Alternatively, the process may comprise a step of inflating a mixture gas into the volume V by means of said hollow element 10, following the sealing step, allowing to control the gas composition inside the volume V in order to generate a modified atmosphere package.

After the sealing step, the process provides for the extraction of the package 200 from the packaging assembly 101. In particular, the upper and lower tools are moved away from one another, passing from the sealing condition to the open condition, in order to allow the package 200 to exit or be extracted from the packaging assembly 101. In case the top film 2 and/or the bottom support 1 are in the form of a continuous film, the process may comprise a cutting phase severing the interconnected packages formed by the packaging station 101 into separate discrete packages. Finally, the discrete packages 200 may be moved from the packaging assembly to a deposit station, for example by means of a conveyor 70.