PACKAGING APPARATUS AND PROCESS

A process of packaging includes providing a bottom support, providing a top film, and forming a closed chamber where a portion of the bottom support, a product and a portion of the top film are housed. The further includes sealing the portion of the bottom support to the portion of the top film along a sealing band circumscribing the product to sealingly house the product in a volume and forming one or more hollow structures by sealing a part of the portion of the top film to a part of the portion of the bottom support at one or more selected seal zones. Before forming the hollow structure, the part of the portion of the top film and of the portion of the bottom support destined to form the hollow structure are maintained separate at a distance the one from the other.

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

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.

SUMMARY

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.

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.

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 cm3/(m2*day*bar), less than 150 cm3/(m2*day*bar), less than 100 cm3/(m2*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 cm3/(m2*day*atm), optionally less than 10 cm3/(m2*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 WO99/54398. 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 1 529 797A and WO2007/093495) 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 U.S. Pat. No. 2,762,720 and EP 1 252 008 A).

The bottom support may be a tray (i.e. a flat tray or a tray with base wall, side wall emerging from the base wall, and top flange) which is formed inline either inside the packaging assembly or inline at a molding station positioned upstream the packaging assembly or which may come from a tray dispenser and thus be performed in a process distinct from the packaging process described herein.

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 cm3/m2*m2*atm, preferably less than 50 cm3/(m2*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 μm and 500 μm, optionally between 60 μm and 3000 μm, even more optionally between 65 μm and 100 μm.

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 μm to 500 μm, optionally from 40 μm to 300 μm, even more optionally from 50 μm to 200 μm; in one embodiment the film, has a thickness of between 65 μm and 100 μm.

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 cm3/(m2*day*atm) and more frequently below 80 cm3/(m2*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 cm3/(m2*day*atm) up to 10000 cm3/(m2*day*atm), more often up to 6000 cm3/(m2*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.

The top film may be a continuous top film which is fed as a continuous film from a supply roll to the packaging assembly or which may be cut into discrete film sheets at a cutting station located upstream the packaging assembly.

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 EVOH 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 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 poly(ethylene 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/cm3to about 0.94 g/cm3. 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/cm3and about 0.94 g/cm3and in particular between about 0.915 g/cm3and about 0.925 g/cm3. Sometimes, linear polyethylene in the density range between about 0.926 g/cm3and about 0.94 g/cm3is 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. Ionomers 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

With reference100it is indicated an apparatus for packaging a product P arranged between a bottom support1and a top film2. The apparatus100is adapted for modified atmosphere packaging, where the top film2is applied to the bottom support1after a modified gas atmosphere has been created inside a volume defined between said bottom support1and top film2. The apparatus100is further adapted for vacuum skin packaging of the product P, where the top film2is draped down on the product P and intimately adheres at least partially to said bottom support1as well as to the product surface thus leaving a minimum, if any, amount of air within the packaging. The apparatus100may also be used in case the top film2applied to the bottom support1and neither vacuum nor modified atmosphere is created, but just the sealing between the film2and the bottom support1is performed.

The apparatus100comprises a frame104defining a base body configured to support various parts of the apparatus100, including at least a packaging assembly101configured to receive at least a portion1aof the bottom support1and a portion2aof the top film2and to engage the portion1awith the portion2aforming a package200for a product P.

Although this should not be interpreted in a limitative manner,FIGS.1and2disclose two possible alternative configurations of packaging apparatus including components additional to the packaging assembly. In particular the apparatus1may include:a bottom support supply assembly103configured for supplying the bottom support1,a transport assembly105receiving the bottom support from the supply assembly103and configured for displacing the portions1aof the bottom support1towards the packaging assembly101,a product loading station111for positioning one or more products P onto respective one or more portions1aof the bottom support1,a top film supply assembly102configured for supplying the top film2to the packaging assembly101.

The transport assembly105may comprise a sliding plane106(as shown in the examples ofFIGS.1and2), which may be, at least partially, a physical plane upon which the bottom support1, in particular the portions1aof the bottom support1, is/are lying and sliding or an ideal plane along which the bottom support1is guided e.g. by means of railways or guides. The sliding plane106is defined on a top area of the frame104and may comprise an endless conveyor belt107positioned on the apparatus frame104according to a closed loop configuration. The conveyor belt107is for example driven by at least one driving roller107aconnected to a driving motor105a, for instance a stepper electric motor, controlled by a control unit50for operating the conveyor belt107with step-by-step movement.

In the example shown inFIGS.1and2, the transport assembly105is carried by, e.g. fixed to, the frame104so that the sliding plane106is substantially horizontal and the conveyor107moves the bottom support1according to an horizontal direction indicated by the arrow A1. The transport assembly105(optionally the conveyor belt107) is configured for displacing the bottom support1along a predefined path from the bottom support supply assembly103to the packaging assembly101where the portion2aof the top film2is tightly fixed to the portion1aof the bottom support1, as it will be explained herein below in detail.

The conveyor107displaces the bottom support1inside the packaging assembly101in proper position for receiving the top film2. For instance, a control unit50(which will be further described below) may control the conveyor107to displace a prefixed number of portions1aper time from a region outside the packaging assembly101, to a region inside the packaging assembly101where the portion or portions1aare vertically aligned to respective top film portions2a. The conveyor107may for instance include a transfer device108(seeFIG.2) configured for picking up one or more portions1aof the bottom support1from the conveyor belt107and bringing them into the packaging assembly101. Note that the products P may be positioned on the bottom support1(optionally on the portion1aof the bottom support1) either upstream the packaging assembly101(FIG.1) or inside said packaging assembly101(FIG.2).

As shown inFIG.1, the bottom support supply assembly103may be configured for supplying a continuous film from a bottom film supply roll112: consecutive portions1aof the bottom support1correspond to consecutive portions of the continuous bottom film unrolled from the bottom film supply roll112. The continuous film is positioned on the sliding plane106of the conveyor belt107and driven by this latter towards the packaging assembly101. The bottom film supply roll112may 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 unit50is connected to said actuator or motor of the bottom film supply roll112in order to control rotation of this latter and consequently control the release of the continuous film support on the conveyor belt107. In one possible non-limitative variant, the control unit50may be configured to synchronize the step-by-step movement of the transport assembly105(in particular of the conveyor belt107) with the rotation of the continuous film roll112. The bottom support supply assembly103thus allows the one or more portions1aof the bottom support1to move from the supply roll112to the transport assembly105, optionally on the sliding plane106defined by a top surface of the conveyor belt107; the conveyor belt107defines an operative tract configured for receiving a plurality of consecutive portions1a.

Alternatively, the bottom supply assembly103may supply the bottom support film1in the form of portions1aconstituted by separate discrete film sheets as shown inFIG.2. In this case, a cutting assembly (not shown) may be located outside the packaging assembly101and configured to cut a continuous film into the discrete film sheet. Alternatively, the cutting assembly may be placed between the continuous film supply assembly103similar to that ofFIG.1and the packaging assembly101, such that the cutting takes place before the bottom support1reaches the packaging assembly101.

In the variant ofFIG.2, the portions1aof the bottom support1are defined by a plurality of distinct discrete portions1astacked in a support loading station of the support supply assembly103configured for dispensing and loading the plurality of distinct portions1aon the operative tract of the conveyor107. In this configuration, the support loading station is connected to the control unit50of the apparatus100to control the dispensing and thus deposit of the one or more portions1aof the bottom support1on the conveyor operative tract: for example, the control unit50may be configured for commanding the support loading station to position consecutive portions1aon the operative tract such that each portion1ais located at a pre-determined distance from an adjacent portion1a. As shown inFIG.2, the support loading station is configured for storing a plurality of said portions1aand for sequentially supplying, under the control offered by the control unit50, one or more portions1ato the conveyor107. The control unit50is connected to the transport assembly105and to the support loading station103in order to synchronize the discontinuous stepping movement of the transport assembly105with the positioning—executed by the support loading station—of the portions1aon the sliding plane106of the same transport assembly105.

The apparatus100ofFIGS.1and2has the product loading station111located downstream the support loading station103or downstream the bottom film supply roll112(with respect to the movement of the product P on the sliding plane106of the transport assembly105): the product loading station111is configured for allowing the positioning of one or more products P onto respective one or more portions1aof the bottom support1. The product loading station111may comprise an automatic dispenser of the products P controlled by control unit50.FIG.1shows a product loading station111arranged upstream the packaging assembly101so that the product P might be positioned on the respective portion1aof the bottom support1before said portion1areaches the packaging assembly101. Alternatively, the product loading station111is located at the packaging assembly101so that the product P might be positioned on the portion1aalready arranged inside the packaging assembly101: this is for example the case of the apparatus ofFIG.2where however the product loading station is not represented.

The top film supply assembly102comprises a top film supply roll102asupplying a continuous top film2. The continuous top film supply assembly102may comprise an arm102b(represented in dashed lines inFIGS.1and2) fixed to the frame104and suitable for supporting the top film supply roll102a. Note that the continuous top film2may be fed from the top film supply assembly102to the proper position inside the packaging assembly101with any known means, for instance using driving rollers or driving mechanisms acting upstream and/or downstream the packaging assembly101, or using transport devices acting on the longitudinal borders of the top film2, or combinations of the above means or any other suitable device. In detail, the continuous top film2is defined by a plurality of adjacent portions2aaligned along an unwinding path of the top film2. The top film supply roll102amay 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 unit50is connected to said actuator or motor of the top film supply roll102ain order to control this latter in rotation and consequently control the release of the continuous top film2. The control unit50may be configured to synchronize the step-by-step movement of the transport assembly105(in particular of the conveyor belt107) with the rotation of the top film supply roll102aand, consequently, with the bottom support supply assembly103.

Alternatively, the top film supply assembly102may supply a continuous top film2to a cutting assembly109located outside the packaging assembly101and configured to cut the continuous top film2into said portions2aconstituted by separate discrete film sheets. The cutting assembly109may be placed between the top film supply assembly102and the packaging assembly101, such that the cutting takes place before the top film portions2areach the packaging assembly101(seeFIG.2). A transport device110is configured for receiving the cut film portions2aat the cutting assembly109and positioning the cut film portions2ainside the packaging assembly101. The control unit50of the apparatus100may be connected to and control operation of the cutting assembly109and of the transport device110to control deposition of the one or more portions2aof the top film2on the transfer device110and to synchronize movement of the transfer device with the operation of the packaging station101.

For the sake of illustrative but not limitative purpose, the portions1aand2arespectively of the bottom support1and of the top film2are both supplied to the packaging assembly101in a continuous manner as shown inFIG.1, or they are both supplied to the packaging assembly101as discrete portions as shown inFIG.2. It is not excluded that the portion1aof the bottom support1may be supplied to the packaging assembly101in a continuous manner (FIG.1), while the portion2aof the top film2may be supplied as a discrete portion (FIG.2), or vice versa.

Going now into a more detailed description of the packaging assembly101, this latter is configured for tightly fixing each portion2aof the top film2to a corresponding portion1aof the bottom support1. As described above, the portion1aof the bottom support1may be a portion of a continuous bottom support film (seeFIG.1) or one of said cut film sheets (discrete portions1aas illustrated inFIG.2); similarly, the portion2aof the top film2may be a portion of a continuous film (seeFIG.1) or one of said cut film sheets (discrete portions2aas illustrated inFIG.2).

In particular, the packaging assembly101includes a lower tool6and an upper tool5movable between at least one open condition, a closed condition and a sealing condition. The upper tool5and the lower tool6, in the open condition (seeFIGS.3,4,9,11,15and16), define an open chamber C: the upper and lower tool5,6, during the open condition, are configured to allow the access into said open chamber C of the portion1aof the bottom support1, of the product P positioned or to be positioned on the portion1aof the bottom support1, and of the portion2aof the top film2. The upper and lower tools5,6, in the closed condition delimit a closed chamber C hermetically closed with respect to an atmosphere outside the packaging assembly101. 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 apparatus100, 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 portions1a,2aof the bottom support1and of the top film2in order to fluid-tight seal the product P between said portions1a,2a.

Alternative variants of a packaging apparatus employing the principles of the invention are shown inFIGS.23-26.

For example, as shown inFIG.21, the packaging apparatus100of the invention has a top film supply assembly102in the form of a feed roll102afrom which the top film2is unrolled. The top film2ais then divided into discrete film sheets2aat a cutting station109before entering the packaging assembly101where the discrete film sheets are fixed to an underlying preformed tray300coming from bottom support supply assembly103, which in this case is in the form of a tray dispenser delivering trays (formed in a separate process) on a conveyor (not shown) which then delivers the trays300to the packaging assembly. Note that a step of loading at least a product P on the trays300by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray300outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray300already arranged inside the packaging assembly101.

The trays300ofFIG.21define the bottom portions1aand are seated in the lower tool6of the packaging assembly101.

The trays may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray300positioned in the packaging station101a corresponding film sheet2ais positioned, as shown in the right hand part ofFIG.21. At this point the upper and lower tool are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray300is not formed at the packaging station, there is no need in the variant ofFIG.21to warm the lower tool6in any part thereof.

FIG.22shows a further variant of the packaging apparatus100of the invention wherein the top film is unrolled from a top film supply roll and divided into discrete film sheets before entering the packaging assembly where the discrete film sheets are fixed to a tray formed inline from a discrete bottom sheet during execution of the packaging process at a respective tray molding station. In greater detail, the packaging apparatus100ofFIG.22has a top film supply assembly102in the form of a feed roll102afrom which the top film2is unrolled. The top film2ais then divided into discrete film sheets2aat a cutting station109before entering the packaging assembly101where the discrete film sheets are fixed to an underlying tray301, which in this case is formed in line at a molding station200. The molding station may for example receive pre-cut film sheets from a bottom support supply assembly103in the form of a film sheet dispenser103. The trays formed at the molding station may be delivered to a conveyor (not shown) which then transfers the trays301to the packaging assembly. Note that a step of loading at least a product P on the trays301by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray301outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray301already arranged inside the packaging assembly101.

The trays301ofFIG.22define the bottom portions1aand are seated in the lower tool6of the packaging assembly101. The trays301may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray301positioned in the packaging station101a corresponding film sheet2ais positioned, as shown in the right hand part ofFIG.21. At this point the upper and lower tools5and6are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray301is not formed at the packaging station, there is no need in the variant ofFIG.22to warm the lower tool6in any part thereof.

FIG.23shows another variant of the packaging apparatus of the invention wherein the top film is unrolled from a top film supply roll and divided into discrete film sheets before entering the packaging assembly where the discrete film sheets are fixed to a tray formed inline from in a portion of a continuous bottom sheet during execution of the packaging process at a respective tray molding station. In greater detail, the packaging apparatus100ofFIG.23has a top film supply assembly102in the form of a feed roll102afrom which the top film2is unrolled. The top film2ais then divided into discrete film sheets2aat a cutting station109before entering the packaging assembly101where the discrete film sheets are fixed to an underlying tray301, which in this case is formed in line at a molding station200. The molding station may for example receive a longitudinal segment of a continuous bottom support feed from a bottom support supply roll112. The trays301formed at the molding station remain connected to the continuous bottom support and are then transferred to the packaging assembly. Note that a step of loading at least a product P on the trays301by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray301outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray301already arranged inside the packaging assembly101.

The trays301ofFIG.23define the bottom portions1aand are seated in the lower tool6of the packaging assembly101. The trays301may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray301positioned in the packaging station101a corresponding film sheet2ais positioned, as shown in the right hand part ofFIG.21. At this point the upper and lower tools5and6are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray301is not formed at the packaging station, there is no need in the variant ofFIG.23to warm the lower tool6in any part thereof.

FIG.24shows a yet further variant of the packaging apparatus of the invention wherein the top film is unrolled from a top film supply roll and enters the packaging assembly where a portion of the continuous top sheet is fixed to an underlying preformed tray coming from a tray dispenser. The packaging apparatus100ofFIG.24has a top film supply assembly102in the form of a feed roll102afrom which a continuous top film2is unrolled and fed to the packaging station101remaining a continuous undivided top film. In particular, at each packaging cycle, a portion2aof the continuous top film2is located at packaging assembly101where the film portion2ais fixed to an underlying preformed tray300coming from bottom support supply assembly103, which in this case is in the form of a tray dispenser delivering trays (formed in a separate process) on a conveyor (not shown) which then delivers the trays300to the packaging assembly. Note that a step of loading at least a product P on the trays300by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray300outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray300already arranged inside the packaging assembly101.

The trays300ofFIG.24define the bottom portions1aand are seated in the lower tool6of the packaging assembly101.

The trays may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray300positioned in the packaging station101a corresponding film portion2aof the continuous top film2is positioned, as shown in the right hand part ofFIG.24. At this point the upper and lower tools5and6are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray300is not formed at the packaging station, there is no need in the variant ofFIG.24to warm the lower tool6in any part thereof.

FIG.25shows another variant of the packaging apparatus of the invention wherein the top film is unrolled from a top film supply roll and enters the packaging assembly where a portion of the continuous top sheet is fixed to a tray formed inline from a discrete bottom sheet during execution of the packaging process at a respective tray molding station. In greater detail, the packaging apparatus100ofFIG.25has a top film supply assembly102in the form of a feed roll102afrom which the top film2is unrolled and fed to the packaging station101remaining a continuous undivided top film. In particular, at each packaging cycle, a portion2aof the continuous top film2is located at packaging assembly101where the film portion2ais fixed to an underlying tray301, which in this case is formed in line at a molding station200. The molding station may for example receive pre-cut film sheets from a bottom support supply assembly103in the form of a film sheet dispenser103. The trays formed at the molding station may be delivered to a conveyor (not shown) which then transfers the trays301to the packaging assembly. Note that a step of loading at least a product P on the trays301by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray301outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray301already arranged inside the packaging assembly101.

The trays301ofFIG.25define the bottom portions1aand are seated in the lower tool6of the packaging assembly101. The trays301may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray301positioned in the packaging station101a corresponding film portion2aof the continuous top film2is positioned, as shown in the right hand part ofFIG.25. At this point the upper and lower tools5and6are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray301is not formed at the packaging station, there is no need in the variant ofFIG.25to warm the lower tool6in any part thereof.

FIG.26shows a variant of the packaging apparatus of the invention wherein the top film is unrolled from a top film supply roll and enters the packaging assembly where a portion of the continuous top sheet is fixed to a tray formed inline from in a portion of a continuous bottom sheet during execution of the packaging process at a respective tray molding station. In greater detail, the packaging apparatus100ofFIG.26has a top film supply assembly102in the form of a feed roll102afrom which the top film2is unrolled and fed to the packaging station101remaining a continuous undivided top film. In particular, at each packaging cycle, a portion2aof the continuous top film2is located at packaging assembly101where the film portion2ais fixed to an underlying tray301formed inline from in a portion of a continuous bottom sheet during execution of the packaging process at a respective tray molding station200. The molding station may for example receive a longitudinal segment of a continuous bottom support fed from a bottom support supply roll112. The trays301formed at the molding station remain connected to the continuous bottom support and are then transferred to the packaging assembly. Note that a step of loading at least a product P on the trays301by means of a product loading station111is present: the product loading station111may be operative upstream the packaging assembly so that the product P might be positioned on each respective tray301outside the packaging assembly101; alternatively, the product loading station may be operative at the packaging assembly101so that the product P might be positioned on the tray301already arranged inside the packaging assembly101.

The trays301ofFIG.26define the bottom portions1aand are seated in the lower tool6of the packaging assembly101. The trays301may include at a peripheral portion thereof a preformed cavity destined to form the inferior half of the hollow portion(s) of the final package. Above the tray301positioned in the packaging station101a corresponding film portion2aof the continuous top film2is positioned, as shown in the right hand part ofFIG.21. At this point the upper and lower tools5and6are approached to form the already described closed chamber and the process continues as described above, i.e. either according to the operation cycle described for the first embodiment or according to the operation cycle described for the second embodiment or according to operation cycle described for the third embodiment. As the tray301is not formed at the packaging station, there is no need in the variant ofFIG.23to warm the lower tool6in any part thereof.

The trays300and301described inFIGS.21-26may be flat or substantially flat trays or (as shown) trays having a base wall, a side wall emerging from the base wall, and a top flange radially emerging from a top portion of the side wall. In this latter case, the flange defines the peripheral portion of each support where a preformed cavity is present (in the examples shown having in cross section the shape for of half a circle or of half an ellipse). The preformed cavity in each flange may circularly extend along an angular portion or along the entire circumference of the flange and is destined to form the inferior half of the hollow portion(s) of the final package.

Before further detailing operation of the upper and lower tools, a detailed description of the structure of these tools is provided, which is applicable to all embodiments and variants described above, i.e., also to the variants ofFIGS.21-26.

The upper tool5comprises a respective tool central portion42configured to be located above the product P (seeFIG.4) and facing a tool central portion31of the lower tool6. When properly positioned in the closed chamber C, the product P is located below the portion2aof the top film2and below the central portion42of the upper tool5. The tool central portion42of the upper tool5may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the lower tool6.

The upper tool5further comprises a tool peripheral portion43surrounding said tool central portion42of the same upper tool5and directly facing a tool peripheral portion32of the lower tool (see e.g.FIGS.5-8). In particular, the tool peripheral portion43of the upper tool5extends around and wholly encircles the tool central portion42of the same upper tool5.

The tool central portion42and the tool peripheral portion43of the upper tool5delimit an active surface5a. In detail, the tool peripheral portion43may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the lower tool6. In greater detail, the tool peripheral portion43of the upper tool5shown in the examples of the attached figures defines:a respective inner abutting section43a, for example having a bottom flat shape, wholly encircling the tool central portion42of the same upper tool5,a respective outer abutting section43b, for example having a bottom flat shape, wholly encircling the tool central portion42and the inner abutting section43aof the same upper tool5,a respective intermediate abutting section43cconnecting said inner abutting section43awith said outer abutting section43b. The intermediate abutting section43chas a bottom concave shape (e.g., with a substantially ‘C’ shaped profile—seeFIGS.3,4,9,9A and10) with concavity facing the lower tool6.

On its turn, the lower tool6comprises a tool central portion31configured for directly contacting and supporting the portion1aof the bottom support1, which as we already described serves for supporting said product P. The tool central portion31is configured to be located below the product P (seeFIG.4). Thus, when the product P is positioned in the closed chamber C, said product P is located above the portion1aof the bottom support1and, specifically, above the central portion31of the lower tool6. The tool central portion31may have a flat shape or, as shown in the enclosed figures, may define at least one cavity having concavity facing the upper tool5; the tool central portion31of the lower tool6may be provided with multiple seats in order to house a plurality of portions1aand corresponding products P.

The lower tool6further comprises a tool peripheral portion32surrounding the tool central portion31. In particular, the tool peripheral portion32of the lower tool6extends around and wholly encircles the tool central portion31.

In greater detail, the tool peripheral portion32may have a flat shape or, as shown in the enclosed figures, may define at least one cavity, having concavity facing the upper tool5. In detail, the tool peripheral portion32shown in the example of the attached figures defines:an inner abutting section32a, for example having a top flat shape, wholly encircling the tool central portion31,an outer abutting section32b, for example having a top flat shape, wholly encircling the tool central portion31and the inner abutting section32a,an intermediate abutting section32cconnecting the inner abutting section32awith the outer abutting section32b. The intermediate abutting section32chas a top concave shape (e.g., with a substantially ‘C’ shaped profile—seeFIGS.3,4,9,9A and10) with concavity facing the upper tool5.

The structure of the tool peripheral portion43of the upper tool5allows to form, in cooperation with the tool peripheral portion32of the lower tool6, a hollow structure4during the sealing condition of the packaging assembly101. In particular, the inner abutting section43aand the inner abutting section32aare configured to cooperate in the formation of the sealing band3, while the intermediate abutting section43cand the intermediate abutting section32c, thanks to their concave conformation, are configured to cause formation of said one or more hollow structures4. The outer abutting section43bof the upper tool and the outer abutting section32bof the lower tool are configured to ensure a complete fluid-tight sealing of the whole package200and of each hollow structure4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band3. It is indeed worth noting that, as shown inFIG.20, after the sealing condition, the hollow structure4comprises at least one tubular section surrounding the central portion.

Finally, as shown in the enclosed figures, the shape of the tool peripheral portion43lower surface of the upper tool5may mirror the shape of the upper surface of the tool peripheral portion32of the lower tool6. On the other hand, the tool central portion42and the tool peripheral portion43of the upper tool5delimit the active surface5awhich, when the portion2aof the top film is located inside the chamber C of the packaging assembly101, is configured to directly face and be active on the portion2aof the top film2. At the same time, the tool central portion31and the tool peripheral portion32of the lower tool6delimit an active surface6awhich, when the portion1aof the bottom support1is located inside the chamber of the packaging assembly101, is configured to directly face and support said portion1a.

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 tool5further comprises an outer closing surface5bsurrounding the active surface5aof the same upper tool5, while the lower tool6further comprises an outer closing surface6bsurrounding the active surface6aof the same lower tool6.

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

In a first alternative, the outer closing surface5bof the upper tool5may be defined by an outer portion (for example of flat conformation), integral with the tool peripheral portion43of the upper tool5: as shown inFIGS.3-10, the outer closing surface5bis positioned at, or in alignment with, the bottom surface of the outer abutting section43b, and optionally also in alignment with the bottom surface of the inner abutting section43a, of the upper tool5. The outer closing surface5bextends around and wholly encircles or delimits the bottom surface of tool peripheral portion43of the upper tool5.

In this first alternative ofFIGS.3-10, the lower tool6may comprise a sleeve48slidingly mounted outside the tool peripheral portion32and terminally defining the outer closing surface6bof the lower tool6, which may be for example of flat conformation; the sleeve48may be normally pushed in the position for example shown inFIG.9by the action of a spring device or by an actuator controlled by control unit50, such that the outer portion6b(when the tools are in the open configuration) is normally positioned at a level above the top surface of the outer abutting section32b, and optionally also of the top surface of the inner abutting section32a, of the lower tool6. When the upper and lower tools5and6are moved to the closed condition (seeFIGS.6and9A), the closing surface5band the closing surface6binteract to define a peripheral closure and form the closed chamber C. Note the outer closing surface6bextends around and wholly encircles or delimits the tool peripheral portion32of the lower tool6and faces the closing surface5bof the upper tool5in order to form a tight closure therebetween, while still maintaining the inner abutting section32aand the outer abutting section32bof the lower tool apart respectively from the inner abutting section43aand the outer abutting section of the43bof the upper tool. An additional sealing body80(such as an annular gasket or an O-ring) may be interposed between the closing surface5bof the upper tool5and the closing surface6bof the lower tool6. When the upper and lower tools5,6are relatively moved by a further relative stroke to the sealing condition, the sleeve48is relatively lowered with respect to the lower tool6as shown inFIGS.7and8, such that the closing surface6b(an thus also the closing surface5b, 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 inner abutting section43aand the inner abutting section32acooperate in the formation of the sealing band3, while the intermediate abutting section43cand the intermediate abutting section32c, thanks to their concave conformation, are configured to cause formation of said one or more hollow structures4. The outer abutting section43bof the upper tool and the outer abutting section32bof the lower tool ensure a complete fluid-tight sealing of the package200and of each hollow structure4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band3.

Alternatively, as shown inFIGS.11-14, the outer closing surface5bof the upper tool5may be defined by an outer side wall of the tool peripheral portion43of the upper tool5cooperating with an inner side wall of the lower tool6. For example, the closing surface5bmay be defined at an inferiorly protruding part of the tool peripheral portion43extending towards the lower tool6(see againFIGS.11-14). In the embodiment shown inFIGS.11-14therefore, the closing surface5bof the upper tool5is transverse (in particular perpendicular) to the outer abutting section43bof the tool peripheral portion43of the upper tool5. On its turn, the outer closing surface6bof the lower tool6of the example ofFIGS.11-14may be defined by an inner side wall, integral with the tool peripheral portion32of the lower tool6, protruding with respect to the tool peripheral portion32towards the upper tool5. In this example, the closing surface6bof the lower tool6is defined by a surface which transversally emerges from the outer abutting section32bof the tool peripheral portion32of the lower tool6and internally (and tightly) receives the closing surface5bof the upper tool5(inFIGS.11-14both surfaces5band6bare vertical). Of course, the design of the surfaces5band6bmay be such that it is the lower tool closing surface6bbeing defined on an outer side wall of the lower tool6and being tightly received inside a closing surface5bon an inner side wall of the upper tool5. Also in the example ofFIGS.11-14, an additional sealing body80(such as an annular gasket or an O-ring) may be interposed between the closing surface5bof the upper tool and the closing surface6bof the lower tool. The closing surfaces5band6binteract such that when the upper and lower tools are 5 and 6 are moved to the closed condition (seeFIG.12), the closing surface5band the closing surface6binteract to define a peripheral closure and form the closed chamber C. Note the outer closing surface6bextends around and wholly encircles or delimits the tool peripheral portion32of the lower tool6and faces the closing surface5bof the upper tool in order to form a tight closure therebetween, while still maintaining the inner abutting section32aand the outer abutting section32bof the lower tool apart respectively from the inner abutting section43aand the outer abutting section of the43bof the upper tool. When the upper and lower tools are relatively moved by a further relative stroke to the sealing condition, the closing surface6bcontinuous to cooperate with the closing surface5bto keep the closed chamber closed, while the inner abutting section43aand the inner abutting section32acooperate in the formation of the sealing band3and the intermediate abutting section43cand the intermediate abutting section32c, thanks to their concave conformation, cause formation of said one or more hollow structures4. When the upper and lower tools reach the sealing condition, the outer abutting section43bof the upper tool and the outer abutting section32bof the lower tool ensure a complete fluid-tight sealing of the package200and of each hollow structure4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band3.

In a yet further alternative embodiment shown inFIGS.15-18, the upper tool5may comprise an inferiorly open case47, externally surrounding the tool peripheral portion43and the tool central portion42. The bottom of the case47exhibits a bottom peripheral surface (for example of flat conformation) facing the lower tool6and defining the closing surface5bof the upper tool5. In detail, the case47is movable with respect the tool peripheral portion43between:a retracted position, where the bottom peripheral surface of said case47is positioned radially outside the outer abutting section43bof the tool peripheral portion43substantially aligned at the same level (height) of said outer abutting section43b(FIG.15),a protruding position, wherein the bottom peripheral surface of the case47axially protrudes with respect to the tool peripheral portion43towards the lower tool6(seeFIGS.16and17) forming an annular closing surface5babutting against the lower tool closing surface6bor pressing film material against the lower tool closing surface6b.

In this latter embodiment, during the closed condition of the upper and lower tools, the case47is arranged in the protruding position with the closing surface5bin close proximity to or in contact against the closing surface6bof the lower tool6(seeFIGS.18and19), in order to define the closed chamber C and, at the same time, allow the active surfaces5a,6ato remain separate. During the passage of the upper and lower tools from the closed to the sealing condition, the case47relatively moves from the protruding back to the retracted position allowing the active surfaces5a,6aof the upper and lower tools to define the sealing band3and the hollow structure(s)4. In the example ofFIGS.15-18, the outer closing surface6bof the lower tool6may be defined by an outer portion (for example of flat conformation), integral with the tool peripheral portion32of the lower tool6; the outer surface6bis positioned at, or in alignment with, the top surface of the outer abutting section32b, and optionally also with the top surface of the inner abutting section32a, of the lower tool6. The outer closing surface6bextends around and wholly encircles or delimits the tool peripheral portion32of the lower tool6and faces the closing surface5bof the upper tool in order to form a tight closure therebetween, when the tools5and6are brought in the closed condition, with the case in the protruding position (FIG.17). Also in this example additional sealing body80(such as an annular gasket or an O-ring) may be interposed between the closing surface5bof the upper tool and the closing surface6bof the lower tool. When the tools5and6in the closed condition (seeFIG.17), outer closing surface6bextends around and wholly encircles or delimits the tool peripheral portion32of the lower tool6and faces the closing surface5bof the upper tool in order to form a tight closure therebetween, while still maintaining the inner abutting section32aand the outer abutting section32bof the lower tool apart respectively from the inner abutting section43aand the outer abutting section of the43bof the upper tool. It is noted that with the packaging station in the closed condition ofFIGS.16and17, the access16is formed by a channel formed by the case47or between the case47and the upper tool peripheral portion43: the access may be connected to the gas source15or to the suction source13to 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 case47moves to its retracted position (FIG.18), the closing surface6bcontinuous to cooperate with the closing surface5bto keep the closed chamber closed, while the inner abutting section43aand the inner abutting section32acooperate in the formation of the sealing band3and the intermediate abutting section43cand the intermediate abutting section32c, thanks to their concave conformation, cause formation of said one or more hollow structures4. When the upper and lower tools reach the sealing condition, the outer abutting section43bof the upper tool and the outer abutting section32bof the lower tool ensure a complete fluid-tight sealing of the package200and of each hollow structure4, which by virtue of the design of the upper and lower tools is/are formed peripherally outside the sealing band3.

In a variant of the example ofFIGS.15-18, the case47may cooperate with the radially external side wall of the lower tool6and the closing surface6bbe defined at the superior part of the case47and extend transversally (in particular perpendicular) to the outer abutting section32bof the tool peripheral portion32of the lower tool6. In this case, the position of the case47would be overturned compared to what is shown inFIGS.15-18and the upper tool5would include an outer portion (for example of flat conformation), integral with the tool peripheral portion43of the upper tool5. Operation would be similar to what just described with reference toFIGS.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 surface5aof the upper tool5comprises a plurality of first holes44in fluid communication with at least one suction source13via first channels44a. The suction source13is configured to withdraw gas from said first holes and cause the portion2aof the top film2to adhere to the active surface5aof the upper tool5. In detail, the suction source13is configured to withdraw gas from the closed chamber C, during the closed condition of the upper and lower tool in order to cause the portion2aof the top film to intimately adhere to the active surface5a. The suction source13comprises at least one vacuum pump13aand at least one evacuation line13bconnecting the inside of said chamber C to the vacuum pump via the first holes44. The suction source13may comprise a valve13cactive on said evacuation line13band configured to regulate the gas flow passage through said line. The control unit50controls the vacuum pump13aand/or the valve13cto withdraw gas from the closed chamber C via said first holes44.

The tool peripheral portion43and the tool central portion42of the upper tool5are made, at least partially, in a heat conductive material: this allows to heat the upper tool thereby allowing the portion2aof the top film2to be correctly sealed to the portion1aof the bottom support1during the sealing condition. In detail, the upper tool5comprises 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 surface5aof the upper tool5to allow heating of the portions2aof the top film2dedicated to be directly sealed with the portion1aof the bottom support1. 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 portion43of the upper tool5allowing this latter to form the sealing band3and the hollow structure4. The heater (again for example in the form of an electric resistor) may be also located at the active surface5aof the upper tool5directly facing the product P arranged on the portion1aof the bottom support1; in other words, the heater may be arranged at the tool central portion42of the upper tool5allowing the portion2aof the top film to warm and get deformable. In particular, when the portion2aof the top film2is put in contact to the active surface5aof the upper tool by means of the suction source13, the heater causes the portion2ato heat up to a temperature sufficient to allow the same portion2ato heat bond (heat-seal) the portion1aof the bottom support1.

Similar to the upper tool, also the active surface6aof the lower tool6may comprise a plurality of second holes33in fluid communication, via second channels33a, with the same or another suction source13: although indicated with same reference number, suction source13may include a single suction source active on the first and second holes or separate suction sources13, 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 source13active on the second holes33is configured to withdrawn gas from said second holes to cause the portion1aof the bottom support1to adhere the active surface6aof the lower tool6. In detail, the suction source13is configured to withdrawn gas from the closed chamber C, at least during the closed condition of the upper and lower tools5and6, in order to pull the portion1aof the bottom support in adhesion to the active surface6a. The control unit50may for example control vacuum pump13aand/or valve13cof the suction source13active on the second holes to withdraw gas from said second holes33.

According to a further aspect, the tool peripheral portion32and, in certain cases, the tool central portion31of the lower tool6are made, at least partially, in a heat conductive material. This allows to heat the lower tool thereby allowing the portion1aof the bottom support1to be correctly sealed to the portion2aof the top film during the sealing condition. In detail, the lower tool6comprises 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 surface6aof the lower tool to heat the portions1aand to allow heat sealing one or more parts of said portions1a,2aof the bottom and top film, during the sealing condition. In particular, the heater may be located at the active surface6aof the lower tool6to allow heating of the portions1aof the bottom support1dedicated to be directly sealed with the portion2aof the top film2; in detail, the heater is arranged at least at the tool peripheral portion32of the lower tool6allowing this latter to define, in cooperation with the tool peripheral portion43of the upper tool5, the sealing band3and the hollow structure4.

According to a further aspect, the lower tool may comprise, preferably at a central portion31thereof, an insulating body31aat 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 body31ais in fact configured to receive the part of the film portion1aabove which the product will rest, thereby avoiding excessive warming of products during packaging. According to a further aspect, the insulating body31amay be cooled: for example a cooling circuit31b(schematically represented in the figures) may be positioned adjacent to the insulating body31aor 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 portion1aat a temperature below a set temperature, for example below 30° C.

After the above description of the structure upper and lower tools5,6, here it is provided an indication about how the tools may cooperate together and with the other parts of the apparatus100.

As mentioned above, the upper and lower tools5,6are movable at least between the open condition, the closed condition and the sealing condition. In detail, at the open condition, the outer closing surfaces5b,6band the active surfaces5a,6aof the upper and lower tool5,6are spaced from each other in order to allow the portions1a,2ato be placed between the active surfaces of the upper and lower tools5,6; during the open condition the chamber C is open and the active surfaces5a,6aare generally at their maximum distance from each other. When the upper and lower tools are relatively approached (under the control of unit50), they initially reach the closed condition. With the tools in the closed condition, the upper and lower tools are positioned such that:the active surfaces5a,6aof the upper and lower tools5,6are still spaced from each other,the outer closing surfaces5b,6bare proximate to each other: in particular, the closing surface5bof the upper tool5tightly abuts against the closing surface6bof the lower tool6(optionally with interposition of the film portions1a,2a) to hermetically close said packaging chamber C with respect to an atmosphere outside the apparatus; at said closure surfaces5b,6b, sealing body80(such as an annular gasket or an O-ring or other element) is squeezed between the surfaces5band6bthereby facilitating a gas tight closure of the chamber C.

At least during the closed condition, the at least one suction source13is activated in order to withdraw gas from the first and second holes, allowing the portion1aof the bottom support to adhere to the active surface6aof the lower tool6and allowing the portion2aof the top film2to adhere to the active surface5aof the upper tool5. It should be noted that, the suction source13may be activated also while the upper and lower tools5,6are still in the open condition; in this case, the portions1a,2ahave to be arranged in proximity of the active surface6a,5a, respectively, allowing the second and first holes to pull said portions in contact with the respective active surfaces (seeFIGS.4,11and15). Thanks to the suction source13and the first and second holes44,33, the upper and lower tools5,6are configured to maintain said portion2aof the top film2and said portion1aof the bottom support1separated the one from the other, at least during the closed condition.

The control unit50may then move the upper and lower tools to the sealing condition. During the sealing condition (seeFIGS.7,8,10,13,14,18and19) at least part of the upper tool5and part of the lower tool6become very close and lead to contact said portions1a,2aof the bottom support1and of the top film2in order to seal said portions and form a package200containing the product. In greater detail, the upper and lower tools5,6, in said sealing condition, are configured to seal the portion1aof the bottom support1to the portion2aof the top film2along a sealing band3circumscribing the product P to sealingly house the product P in a volume V between said portion2aof the top film2and said portion1aof the bottom support1. Furthermore, the upper and lower tool, in said sealing condition are configured to form one or more hollow structures4by sealing a part of said portion2aof the top film2to a part of said portion1aof the bottom support1at one or more selected seal zones; as shown inFIG.20, the hollow structure4extends around and wholly encircles said sealing band3. In detail, during the sealing condition, the tool peripheral portion32of the lower tool6approaches and almost contacts the tool peripheral portion43of the upper tool5(FIGS.7,8,10,13,14,18and19); moreover, during the sealing condition the components of the packaging assembly are configured to interact as follows:the inner abutting section32aof the lower tool faces and is vertically aligned with the inner abutting section43aof the upper tool5; in particular, the inner abutting section32aof the lower tool6directly contacts the portion1aof the bottom support1, while said inner abutting section43aof the upper tool5directly contacts the portion2aof the top film2: the inner abutting section32aand the inner abutting section cooperate to bring portion1aof the bottom film in contact with portion2aof the top film at selected areas in particular forming the sealing band3which sealingly joins the portions1aand2atightly insulating the product inside the volume V;the intermediate abutting section32cof the lower tool6faces the intermediate abutting section43cof the upper tool5; in particular, the intermediate abutting section32cof the lower tool6directly contacts the portion1aof the bottom support1while the intermediate abutting section43cof the upper tool5directly contacts the portion2aof the top film2: the intermediate abutting sections32c,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 structures4adjacent to, and radially external from, the sealing band3;the outer abutting section32bof the lower tool faces the outer abutting section43bof the upper tool5; in particular, the outer abutting section32bof the lower tool6, which directly contacts the portion1aof the bottom support1, and the outer abutting section43b, which directly contacts the portion2aof the top film2, bring said portion1ain contact with the portion2aof the top film2; moreover, the outer abutting sections32b,43brespectively of the lower and upper tool, during the sealing condition, face each other and are configured to define an outer sealing band30which fluid-tightly seals the package200; as schematically shown inFIG.20, the one or more hollow structures4formed is interposed between the sealing band3and the outer sealing band30.

In order to relatively move the upper and lower tools5,6between the above described open condition, closed condition and sealing condition, the apparatus100has at least one main actuator60active on at least one of said upper and lower tool5,6and controlled by the control unit50. In practice, the main actuator60may be any kind of electric, pneumatic or hydraulic actuator configured for lifting and lowering one or both tools5,6along a direction transverse (see e.g. the vertical direction identified with reference A2inFIGS.1and2) to said horizontal direction A1.

Furthermore, the apparatus100comprises at least a discharge conveyor70disposed downstream the packaging assembly101with respect to said horizontal direction A1. Discharge conveyor70is configured for displacing the formed package200towards a deposit station (not shown) placed downstream the packaging assembly101. The conveyor70is controlled by the control unit50to be either continuously active or at least active during the open condition of the apparatus100: a pick-up mechanism (also not shown) may be present between the packaging station101and the discharge conveyor to bring the formed package200from the closed chamber C onto the discharge conveyor70during the open condition of the upper and lower tools5and6following the sealing condition once the package200is formed.

In greater detail, the control unit50is configured to command the packaging assembly101to execute the following steps:positioning the upper and lower tools5,6in the open condition;then positioning the upper and lower tools5,6in the closed condition, with the portion1aof the bottom support1, the product P and the portion2aof the top film2received inside the closed chamber C;then sealing the portion1aof the bottom support1to the portion2aof the top film2along the sealing band3circumscribing the product P to sealingly house the product P in the volume V between said portion2aof the top film2and said portion1aof the bottom support1: the sealing step takes place moving the upper and lower tools5,6as described above from the closed condition to the sealing condition whereby the tool peripheral portions32and43respectively of the lower and upper tools bring portions1a,2ain 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 portions32and43to reach the temperature needed for the heat bonding and formation of the sealing band3;forming the one or more hollow structures4by sealing a part of said portion2aof the top film2to a part of said portion1aof the bottom support1at one or more selected seal zones; this step of forming the hollow structure4is preferably executed by moving the upper and lower tools from the closed condition to the sealing condition, simultaneously with the formation of the sealing band3;before the step of forming the one or more hollow structures4(and preferably before both the steps of formation of the sealing band3and of formation of the one or more hollow structures4), and after formation of the closed chamber C, maintaining at least the peripheral part of portion2aof the top film2separate and at a distance from the underlying peripheral part of portion1aof the bottom support1; optionally, as shown in the attached figures before the steps of forming the one or more hollow structures4and of forming the sealing band3, the control unit controls the packaging assembly101to keep the entire portion2aspaced apart from the underlying portion1a(seeFIGS.5,12and17); 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 structures4, as it will be further explained herein below.

As just described, the upper and lower tools5,6, are configured to maintain the portions1aand2a(or parts thereof) separate thanks to the ability of positioning the active surfaces5a,6amutually apart and thanks to the action of the suction source13which is in fluid communication with the first and second holes33,44of the lower and upper tools, respectively. In particular, the control unit50is also connected to the suction source13and configured to (after commanding the packaging station in the closed condition of the upper and lower tools5,6, and at least during said closed condition before the sealing step takes place) command the suction source13to withdrawn gas from the first and second plurality of holes44,33in order to separate the portion2aof the top film2and the portion1aof the bottom support1by adhering said portion2aof the top film2to the active surface5aof the upper tool5and by adhering said portion1aof the bottom support1to the active surface6aof the lower tool6.

In this way, following the passage of the upper and lower tools from the closed to the sealing condition, the tool peripheral portions43,32of the upper and lower tools5,6allow to form one or more hollow structures4.

As shown in the enclosed figures, the packaging apparatus100may also comprise at least one gas source15(FIGS.4-8and11-17) in fluid communication with at least one access16defined on at least one between the upper tool5and the lower tool6. The access16is configured to put in fluid communication the gas source15with the closed chamber C and/or the volume V, at least during the closed condition of the upper tool5and the lower tool6of the packaging assembly101. The gas source15comprises an inflation pump15aand an inflation line15bconnecting said pump15awith the access16. Furthermore, the gas source15may comprise a regulating valve15cactive on the inflation line15band configured to regulate the flow passage through said line15b. The control unit50is connected with the gas source15and it is configured to (after commanding the packaging station in the closed condition of the upper and lower tools5,6, and at least during said closed condition before the sealing step takes place) command the gas source15to inflate gas into the closed chamber C through the access16.

The control unit50is configured to command the gas source15(e.g. acting on the inflation pump15aand/or on the regulating valve15c) for inflating gas into the closed chamber C through the access16at 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 source13via the first and second plurality of holes44,33; 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 structures4housing 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 apparatus100may comprise at least one hollow element10, e.g. a hollow needle, operative inside a seat14defined on at least one between the upper and lower tools5,6. The hollow element10is configured to pierce at least one of the portion of the top film2and the portion of the bottom support1and to be inserted at least partially inside the volume V: the hollow element10is further configured to inject into and/or withdrawn gas from the volume V. In the enclosed figures, the hollow element10is supported, in a non-limiting way, by the lower tool6; it is not excluded that the hollow element10be associated to the upper tool5or that at least one hollow element10may be provided for each of said lower and upper tools.

According to a currently preferred variant, the hollow element is carried by the lower tool6and is configured to pierce the portion1aof the bottom support. In particular, as shown in the figures, the hollow element10may be operative in correspondence the radial periphery of the lower tool central zone31, close to the inner abutting section32aof the tool peripheral portion32: this allows the hollow element(s)10, when operated, to pierce the bottom support1far 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)10in the bottom support1closed by the draping down of the top film portion2aon the product and on the bottom support portion1anot covered by the product.

The hollow element10is relatively movable with respect to the upper and/or the lower tool5,6at least between:a retracted position, where the hollow element10is spaced from the portion1aof the bottom support1and spaced from the portion2aof the top film2(FIGS.3-5,8-11and14-16), andan advanced position, where the hollow element10pierces at least one between the portion1aof the bottom support1and the portion2aof the top film2; the hollow element10, 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 portions1a,2aof the bottom support1and the top film2(FIGS.6-7,12-13and17-19).

The hollow element10is configured to be put in fluid communication with the gas source15. The control unit50is connected to the hollow element10and to the gas source15; the control unit50is also configured to control operation of the gas source15and command the hollow element10(acting on an appropriate actuator) to move between the retracted and the advanced position. In particular, the control unit50is configured to define an inflating cycle comprising:command the hollow element(s)10to move from the retracted position to the advanced position at least during the closed condition of the upper and lower tools5,6,with the hollow element(s) in the advanced position, command the gas source15to inflate gas inside the volume V through said hollow element(s)10.

As mentioned above, the packaging apparatus100may also be adapted for forming modified atmosphere packaging: in this case, the packaging assembly101may be configured to create inside volume V defined between said bottom support1and top film2a modified gas atmosphere. The hollow element10may thus be used to inject inside the volume V a specific gas in order to define said modified atmosphere packaging. The control unit50may also be configured to control the gas source15in 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 element10may also be in fluid communication with the suction source13(e.g. it could be configured to draw gas from the chamber C and volume V through the first and/or second holes44,33) for withdrawing gas from the volume V for defining a vacuum skin package surrounded by said one or more hollow structures (seeFIG.20). The control unit50is operative on the actuator connected to the hollow element(s)10and on the suction source13. The control unit is configured to control the operations of the suction source13and—as described above—command the hollow element(s) in the retracted and in the advanced position. The control unit50may in particular be configured to:command the hollow element10to move from the retracted position to the advanced position at least during the sealing condition of the upper and lower tools5,6,with the hollow element(s) in the advanced position and with the tools in the sealing condition, command the suction source13to withdraw gas from the volume V through said hollow element10.

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 element10to move from the advanced position back to the retracted position,with the hollow element(s) in the retracted position, command the suction source13to 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 source13to also interrupt the withdrawal of gas from the first and/or second plurality of holes in order to allow the portions1a,2aof the bottom support1and of the top film2to wrap the product P and intimately adhere one against the other in correspondence of those areas of portions1aand2anot 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 portions1aand2awith each other.

With the step of withdrawing gas from the volume V, the apparatus100is thus able to form a vacuum skin package.

Note that also when forming the vacuum skin packages, the hollow structure(s)4are formed preferably by inflating gas into the closed chamber. In particular, the control unit50may be configured to execute first the inflating cycle described above and then a suction cycle comprising:commanding the upper and lower tools5,6to move from the closed condition to the sealing condition,move the hollow element(s)10to the advanced position and with the upper and lower tools in the sealing condition, commanding the gas source15to interrupt the inflation of gas into the volume V,maintaining the hollow element(s)10in the advanced position and the upper and lower tools in the sealing condition, commanding the suction source13to 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)10to move from the advanced position back to the retracted position,commanding the suction source13, with the hollow element10in the retracted position, to interrupt the withdrawal of gas from the volume V,commanding the suction source13, 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 portions1a,2aof the bottom support1and of the top film2to wrap the product P and intimately adhere one against the other in correspondence of those areas of portions1aand2anot 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 portions1aand2awith each other.

Although the apparatus100may have one or both the suction source13and the gas source15, it is to be understood that the control unit50of the apparatus100may also be configured to tightly engage the portion2aof the top film2to the portion1aof the bottom support1without activating the suction source or the gas source and thus leaving a normal environment atmosphere within the package.

Subsequently to the formation of the package200, the control unit50is configured to command the upper and lower tools5,6in the open condition to allow the package to be extracted from the packaging assembly101, and new portions1a,2awith 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 apparatus100disclosed above and/or according to enclosed claims. The process takes place under control of control unit50and achieves a process of packaging a product P between a bottom support1(e.g. in form of a film sheet having substantially the same structure of the top film2or in form of a tray) and a top film2. In this case the described process allows making a skin packaging of the product. In any case the apparatus100is also capable of packaging products P under modified atmosphere. Moreover, the apparatus100may be used for applying the top film2to a bottom support1and thus form packaging under normal ambient atmosphere.

The packaging process comprises a step of supplying, at the same time, the bottom support1from the bottom support supply assembly103and the top film2from the top film supply assembly102such that one or more bottom support portions1aand one or more top film portions2areach the packaging assembly101while 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 portions1a,2aof the bottom support1and of the top film2are positioned inside the packaging assembly in open condition with the upper and lower tools5,6defining said chamber C, which at this point is still open. The positioning step of said portions1a,2amay be done automatically by the control unit50acting on the bottom support supply assembly103and the top film supply assembly102, or acting on the transfer device108of the portions1aand the transport device110of the portions2a.

The process further comprise a step of loading at least a product P on the portion1aof the bottom support1by means of a product loading station111which may be operative upstream the packaging assembly (seeFIG.1) so that the product P might be positioned on the portion1aoutside the packaging assembly101or which may be located at the packaging assembly101so that the product P might be positioned on the portion1aalready arranged inside the packaging assembly101.

Following positioning of portions1a,2aand of product P inside the packaging assembly101, 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 portion1aof the bottom support1, the product P above said portion1aof the bottom support1, and a portion2aof the top film2above said product P and said portion1aof the bottom support1. In detail, the closed chamber C is defined by moving the upper and lower tools5,6from the open condition to the closed condition, as described above.

With the mentioned components, namely said portion1aof the bottom support1, said product P, said portion2aof the top film2located inside the closed chamber C, and with the upper and lower tools in the closed condition, the active surfaces5a,6aof the upper and lower tools5,6are spaced from each other while the outer closing surfaces5b,6bof 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 portion2aof the top film2and said portion1aof the bottom support1are maintained separate at a distance the one from the other; in particular, at least the part of said portion2aof the top film2and the part of said portion1aof the bottom support1, which are destined to form the one or more hollow structures4are maintained separate at a distance the one from the other. In the examples shown the entirety of portion2aof the top film2and the entirety of portion1aof the bottom support1are maintained separate at a distance the one from the other. This may be achieved by adhering the portion2aof the top film2to the active surface5aof the upper tool5and by adhering the portion1aof the bottom support1to the active surface6aof the lower tool6. In detail, adhering the portion2aof the top film2to the lower active surface5aof the upper tool5is achieved by withdrawing gas through said first holes44by means of said suction source13while adhering the portion1aof the bottom support1to the active surface6aof the lower tool6is achieved by withdrawing gas through said second holes33, by means od said suction source13.

During the closed condition of the upper and lower tools5,6and while portions1a,2aadhere to the respective active surfaces6a,5a, the process provides for inflating a gas into the closed chamber C between said portion2aof the top film2and said portion1aof the bottom support1. In particular, the step of inflating a gas is executed while:said portion1aof the bottom support1, said product P, and said portion2aof the top film2located inside the closed chamber C; andsaid portion2aof the top film2and said portion1aof the bottom support1are maintained separated at a distance the one from the other.

Always during the closed condition of the upper and lower tools5,6and during the adhesion of the portions1a,2ato the respective active surfaces6a,5a, the process may provide a heating of the portions1aof the bottom support1and/or of the portion2aof the top film2allowing softening of said portions1a,2ain order to promote a correct sealing of portion1awith portion2aduring the sealing step described below.

Subsequently, the process comprises the following further steps:sealing the portion1aof the bottom support1to the portion2aof the top film2along a sealing band3circumscribing the product P to sealingly house the product in a volume V between said portion2aof the top film2and said portion1aof the bottom support1; andforming one or more hollow structures4by sealing a part of said portion2aof the top film2to a peripheral part of said portion1aof the bottom support1at one or more selected seal zones; the step of forming one or more hollow structures4comprises forming at least one hollow structure extending around and wholly encircling said sealing band3.

The sealing step comprises a relative displacement of the upper tool5and of the lower tool6from the closed condition to the sealing condition, where at least part of the active surfaces5a,6aof the upper and lower tool5,6are approached to each other and made proximate, leading to a mutual contact between the portions1aand2arespectively of the bottom support1and of the top film2, thereby forming the sealing band3and the hollow structure(s)4.

In detail, before forming the one or more hollow structures4, at least the part of said portion2aof the top film2and the part of said portion1aof the bottom support1, destined to form said one or more hollow structures4, are maintained separate at a distance the one from the other. In particular, the part of the portion1aof the bottom support1destined to cooperate in the formation of the hollow structure(s) is a peripheral portion12surrounding a central portion11of the same portion1aof the bottom support1; similarly, the part of the portion2aof the top film2destined to cooperate in the formation of the hollow structure(s) is a peripheral portion23surrounding a central portion22of the same portion2aof the top film2; note that before said step of forming the one or more hollow structures4, the portion2aof the top film2and the portion1aof the bottom support1are maintained separated the one from the other, and in vertical alignment, in correspondence of said respective peripheral portions12,23destined to form said one or more hollow structures4(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 portion1aof the bottom support1and the portion2aof 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 portion2aof the top film2to the active surface5aof the upper tool5, at least the peripheral portion23of the top film2adheres the active surface5aof the upper tool5. At the same time, during the adhering step of the portion1aof the bottom support1to the active surface6aof the lower tool6, at least the peripheral portion12of the bottom support1adheres the active surface6aof the lower tool6.

As shown inFIGS.4-7,11-13,15-18, the central portion22of the top film2, during the adhering step, is directly in contact with the upper tool central portion42, while the peripheral portion23of the top film2is directly in contact with the tool peripheral portion43of the same upper tool. In particular, the peripheral portion23of the portion2aof the top film2comprises at least:an inner tract23aradially extending from the central portion22of the top film2; the inner tract23a, during the adhering step, faces and directly contacts the inner abutting section43aof the tool peripheral portion43of the upper tool5;a central tract23bradially extending from the inner tract23aof the top film2, away from the central portion22of the same top film2, the inner tract23abeing interposed between the central portion22and the central tract23bof the top film2; the central tract23b, during the adhering step, faces and directly contacts the intermediate abutting section43bof the tool peripheral portion43of the upper tool5;an outer tract23cradially from the central tract23bof the top film2: the central tract23bbeing interposed between the inner tract23aand the outer tract23cof the peripheral portion23of the top film2; the outer tract23c, during the adhering step, faces and directly contacts the outer abutting section43cof the tool peripheral portion43of the upper tool5.

On the other hand, again as shown inFIGS.4-7,11-13,15-18, the central portion11of the bottom support1, during the adhering step, is directly in contact with the tool central portion31of the lower tool while the peripheral portion22of the bottom support1is directly in contact with the tool peripheral portion32of the same lower tool6. The peripheral portion12of the bottom support1comprises at least:an inner tract12aextending from the central portion11of the bottom support1; the inner tract12a, during the adhering step, faces and directly contacts the inner abutting section32aof the tool peripheral portion32of the lower tool6;a central tract12bprotruding from the inner tract12aof the bottom support1, away from the central portion11of the same bottom support1: the inner tract12aof the bottom support1being interposed between the central portion11and the central tract12bof the bottom support1; the central tract12b, during the adhering step, faces and directly contacts the intermediate abutting section32bof the tool peripheral portion32of the lower tool6;an outer tract12cprotruding from the central tract12bof the bottom support1: the central tract12bbeing interposed between the inner tract12aand the outer tract12cof the peripheral portion12of the bottom support1; the outer tract12c, during the adhering step, faces and directly contacts the outer abutting section32cof the tool peripheral portion32of the lower tool6.

Before forming the one or more hollow structures4and while the portion1aof the bottom support1(with the product (P) thereon) and said portion2aof the top film2are located at the packaging station or already located inside the closed chamber C, at least the part of said portion2aof the top film2and the part of said portion1aof the bottom support1, destined to form said one or more hollow structures4, are moved further apart the one from the other from an initial approached condition (where said portion2aand said portion1aare closely adjacent) to reach said position where they are maintained separate at a distance the one from the other (see for exampleFIG.3-5or9,9A). The control unit50is configured to command the packaging assembly101such that the above steps are carried out.

Again referring to a phase before said step of forming the one or more hollow structures4and while said portion1aof the bottom support1(with the respective product P thereon) and said portion2aof the top film2are located inside the closed chamber C, the inner tract23aof portion2aof the top film2and the inner tract12aof said portion1aof the bottom support1(which will then be sealed together to form the radially internal seal/seal band of hollow structure or structures) are maintained separate at a distance the one from the other. As shown inFIG.9A, during the same phase, namely before said step of forming the one or more hollow structures4and while said portion1aof the bottom support1(with the respective product P thereon) and said portion2aof the top film2are located inside the closed chamber C, also the central tract23bof said portion2aof the top film2and the central tract12bof said portion1aof the bottom support1are maintained separate at a distance the one from the other, and also the outer tract23cof said portion2aof the top film2and the outer tract12cof said portion1a(which will then be sealed together to form the radially external seal/seal band30of the hollow structure or structures) of the bottom support1are maintained separate at a distance the one from the other. The control unit50is configured to command the packaging assembly101such that the above steps are carried out.

Note that in a variant (not shown), during said phase before said step of forming the one or more hollow structures4and while said portion1aof the bottom support1(with the respective product P thereon) and said portion2aof the top film2are located inside the closed chamber C, the central tract23bof said portion2aof the top film2and the central tract12bof said portion1aof the bottom support1are maintained separate at a distance the one from the other, while also the outer tract23cof said portion2aof the top film2and the outer tract12cof said portion1a(which will then be sealed together to form the radially external seal/seal band of the hollow structure or structures) of the bottom support1are maintained separate at a distance the one from the other. In this variant, during the same mentioned phase, the inner tract23aof portion2aof the top film2and the inner tract12aof said portion1aof the bottom support1are not maintained separate, but bonded to each other to form the inner sealing band3, while the other sealing band will be formed at a later stage. In this way the zone destined to form the hollow structures may be inflated by accessing the space between the outer tract23cof said portion2aof the top film2and the outer tract12cof said portion1a, while the internal seal band3is already formed. The control unit50is configured to command the packaging assembly101such that the above steps are carried out.

Note that in yet other variant (not shown), during said phase before said step of forming the one or more hollow structures4and while said portion1aof the bottom support1(with the respective product P thereon) and said portion2aof the top film2are located inside the closed chamber C, the central tract23bof said portion2aof the top film2and the central tract12bof said portion1aof the bottom support1are maintained separate at a distance the one from the other, while also the inner tract23aof portion2aof the top film2and the inner tract12aof said portion1aof the bottom support1(which will then be sealed together to form the radially internal seal/seal band3of hollow structure or structures) are maintained separate at a distance the one from the other. In this variant, during the same mentioned phase, the outer tract23cof said portion2aof the top film2and the outer tract12cof said portion1aare not kept separate, but are sealed together to form the radially external seal/seal band30of the hollow structure or structures. In this way inflated gas entering into central volume V (e.g., via channel16), may inflate the zone destined to form the hollow structures, while the external seal band30is already formed. The control unit50is configured to command the packaging assembly101such that the above steps are carried out.

Exclusively during the sealing of the portion1aof the bottom support1with the portion2aof the top film2, the inner tract12aof the portion1ais brought in contact and heat sealed to the inner tract23aof the portion2aand the outer tract12cof the portion1ais brought in contact and heat sealed to the outer tract23cof the portions2a. Following the sealing of the portion1aof the bottom support1with the portion2aof the top film2as just described, the central tract12bof the peripheral portion12of the bottom support1and the central tract23bof the peripheral portion23of the top film2form the one or more hollow structures4(FIG.20).

Moreover, when gas inflating is practiced between the portions1a,2aof the bottom support1and the top film2and thanks to the adhesion of said portions1a,2ato the respective active surfaces5a,6aof the upper and lower tools5,6, the process may define one or more hollow structures4with the desired quantity of gas inside and thus with the desired stiffness. The step of sealing the portion1aof the bottom support1to the portion2aof the top film2along said sealing band3, and said step of forming one or more hollow structures4are 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 element10, optionally a hollow needle, through one of the portion2aof the top film portion2and the portion1aof the bottom support1such that the hollow element10is 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 portion11of the bottom support1and the central portion22of the top film2with the hollow element10in order to pass through said at least one central portion and positioning a terminal portion of the hollow element10inside the volume V. In particular, the hollow element is inserted inside the volume V during the adhering phase of the portions of the bottom support1and of the top film2to the active surface of the lower and upper tool5,6respectively. The gas inflating step may be executed through the inserted hollow element(s)10which may be put in fluid communication with the gas source15. Alternatively, with reference to the example ofFIGS.15-18, the gas inflating step may take place using the access or channel16formed by the case47or between the case47and the upper tool peripheral portion43: the access may be connected to the gas source15to 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 portion2aof the top film2portion to adhere to the product P and to the portion1aof the bottom support1. In particular, the step of withdrawing gas follows the sealing step and may comprise inserting the hollow element10, optionally a hollow needle, through one of the portion2aof the top film portion2and the portion1aof the bottom support1such that the hollow element10is at least partially inserted into the volume V and creates a fluid communication between the volume and the suction source13positioned outside the volume V: operating the suction source13allows to withdraw gas from the volume V through said hollow element10and (once the portions1aand2ahave been released from the respective active surfaces6aand5a) causes formation of a vacuum skin package hosting the product, delimited by the sealing band3and surrounded by the hollow element(s)4.

In fact, before or during said step of withdrawing gas from said volume V, the first holes44, optionally both said first and second holes44,33, are either vented to external atmosphere or supplied with gas at a pressure higher than atmospheric pressure to release the portion2aof the top film2from the active surface5aof the upper tool5and, optionally, to release the portion1aof the bottom support1from the active surface6aof the lower tool6.

Alternatively, the process may comprise a step of inflating a mixture gas into the volume V by means of said hollow element10, 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 package200from the packaging assembly101. 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 package200to exit or be extracted from the packaging assembly101. In case the top film2and/or the bottom support1are in the form of a continuous film, the process may comprise a cutting phase severing the interconnected packages formed by the packaging station101into separate discrete packages.

Finally, the discrete packages200may be moved from the packaging assembly to a deposit station, for example by means of a conveyor70.