PACKAGING MACHINE AND METHOD FOR PRODUCING SEALED PACKAGES

There is described a packaging machine for producing sealed packages of a pourable product from a web of packaging material, the packaging machine comprises an isolation chamber having an inner environment and within which, in use, the web of packaging material is formed into a tube, a conduct assembly being in fluid connection with the inner environment; the conduct assembly defining and/or forming together with the inner environment at least a portion of a flow circuit of the packaging machine, a nitrogen distribution unit configured to inject and/or direct nitrogen into the flow circuit and a flow controlling device configured to create a flow of gas along a flow path within the flow circuit from the inner environment through at least a portion of the conduct assembly back into the inner environment.

TECHNICAL FIELD

The present invention relates to a packaging machine for producing sealed packages of a pourable product, in particular a pourable food product.

The present invention also relates to a method for producing sealed packages of a pourable product, in particular a pourable food product.

BACKGROUND ART

As is known, many liquid or pourable food products, such as fruit juice, UHT (ultra-high-temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by sealing and folding laminated strip packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material (an oxygen-barrier layer), e.g. an aluminum foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Packages of this sort are normally produced on fully automatic packaging machines, which advance a web of packaging material from a magazine unit through a sterilization apparatus for sterilizing the web of packaging material and to an isolation chamber (a closed and sterile environment) in which the sterilized web of packaging material is maintained and advanced. During advancement of the web of packaging material through the isolation chamber, the web of packaging material is folded and sealed longitudinally to form a tube having a longitudinal seam portion, which is further fed along a vertical advancing direction.

In order to complete the forming operations, the tube is filled with a sterilized or sterile-processed pourable product, in particular a pourable food product, and is transversally sealed and subsequently cut along equally spaced transversal cross sections within a package forming unit of the packaging machine during advancement along the vertical advancing direction.

Pillow packages are so obtained within the packaging machine, each pillow package having a longitudinal sealing band, a top transversal sealing band and a bottom transversal sealing band.

In the recent years, sterilization apparatuses have become available, which are configured to sterilize the web of packaging material by means of the application of physical irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation.

A typical sterilization apparatus of this kind comprises an irradiation device typically having a pair of electron beam emitters spaced apart from one another.

A drawback of such sterilization apparatuses is seen in that reaction products may form, which require to be removed and decomposed in a controlled manner, thus increasing the complexity of the design of such packaging machines.

Even though this kind of packaging machine provides for good results, a desire is felt to simplify the design of these packaging machines.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide a packaging machine to overcome, in a straightforward and low-cost manner, at least one of the aforementioned drawbacks.

It is a further object of the present invention to provide a method for producing sealed packages to overcome, in a straightforward and low-cost manner, at least one of the aforementioned drawbacks.

According to the present invention, there is provided a packaging machine and a method according to the respective independent claims.

Preferred embodiments of the packaging machine and the method are claimed in the respective dependent claims.

BEST MODES FOR CARRYING OUT THE INVENTION

Number1indicates as a whole a packaging machine for producing sealed packages2(only partially shown to the extent necessary for the understanding of the present invention) of a pourable product, in particular a pourable food product, even more particular a sterilized or sterile-processed pourable food product, such as pasteurized milk, fruit juice, wine, tomato sauce, etc., from a tube3of a web4of packaging material. In particular, in use, tube3extends along a longitudinal axis, in particular having a vertical orientation.

Web4of packaging material has a multilayer structure (not shown), and comprises at least a layer of fibrous material, such as e.g. a paper or cardboard layer, and at least two layers of heat-seal plastic material, e.g. polyethylene, interposing the layer of fibrous material in between one another. One of these two layers of heat-seal plastic material defines the inner face of package2eventually contacting the pourable product.

Preferably but not necessarily, web4also comprises a layer of gas- and light-barrier material, e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film, in particular being arranged between one of the layers of the heat-seal plastic material and the layer of fibrous material. Preferentially but not necessarily, web4also comprises a further layer of heat-seal plastic material being interposed between the layer of gas- and light-barrier material and the layer of fibrous material.

A typical package2obtained by packaging machine1comprises a longitudinal seam portion and a pair of transversal sealing bands, in particular a transversal top sealing band and a transversal bottom sealing band.

With particular reference toFIG. 1, packaging machine1is configured to advance web4along a web advancement path, to sterilize web4during advancement along the web advancement path, to form tube3from web4, to fill tube3with the pourable product and to form single packages2from the filled tube3.

With particular reference toFIG. 1, packaging machine1comprises at least:an isolation chamber5having an inner environment6(in particular, containing a sterile gas) and separating inner environment6from an outer environment7and within which, in use, web4is formed into tube3;a sterilization apparatus8for sterilizing at least a first face, in particular also a second face, of web4at a sterilization station and comprising a sterilization chamber10having an inner space11being in fluid connection with inner environment6; in particular, web4(i.e. at least the first face, in particular also the second face) is, in use, sterilized within sterilization chamber10and/or inner space11;a conduct assembly15being in fluid connection with inner environment6, and in particular also with inner space11, and defining and/or forming together with at least inner environment6, in particular also with inner space11, a flow circuit of packaging machine1;a nitrogen distribution unit16configured to inject and/or direct nitrogen into the flow circuit, in particular conduct assembly15, at an injection station17; anda flow controlling device18configured to create a flow of gas along a flow path Q and within the flow circuit from inner environment6through at least a portion of conduct assembly15back into inner environment6, in particular from inner environment6into inner space11and from inner space11through at least a portion of conduct assembly15into inner environment6.

According to a preferred non-limiting embodiment, packaging machine1also comprises, a control valve19, in particular a three-way valve, connected to, in particular being integrated into, conduct assembly15, and configured to control an evacuation and/or releasing of a portion of the gas flowing, in use, along flow path Q from the flow circuit.

According to a preferred non-limiting embodiment, packaging machine1also comprises a control device (not shown) configured to at least partially control operation of packaging machine1.

According to a preferred non-limiting embodiment, packaging machine1also comprises a gas sensor21, configured to determine and/or measure a nitrogen content and/or an oxygen content within the gas flowing along flow path Q and/or within the flow circuit.

According to a preferred non-limiting embodiment, the flow circuit is a closed flow circuit. In particular, the closed flow circuit is configured and/or constructed such that uncontrolled losses of the gas flowing along the flow path Q and/or within the flow circuit are limited.

According to a non-limiting embodiment, it may be possible to extract gas from the (closed) flow circuit in a controlled manner.

According to a preferred non-limiting embodiment, packaging machine1also comprises:a tube forming device (not specifically shown) extending along a longitudinal axis, in particular having a vertical orientation, and being arranged, in particular at a tube forming station23and, at least partially, preferably fully, within isolation chamber5, in particular inner environment6, and being adapted to form tube3from the, in use, advancing (and sterilized) web4; and/ora sealing device (not shown) at least partially arranged within isolation chamber5and being adapted to longitudinally seal tube3formed by the tube forming device so as to form a longitudinal sealed seam portion of tube3; and/ora filling device25for filling tube3with the pourable product, in particular the pourable food product; and/ora package forming unit26adapted to at least form and transversally seal tube3, in particular the, in use, advancing tube3, for forming packages2; and/ora conveying device configured to advance web4along the web advancement path to tube forming station23and to advance tube3along a tube advancement path towards and at least partially through package forming unit26.

In particular, package forming unit26is arranged downstream of isolation chamber5and the tube forming device along the tube advancement path.

According to a preferred non-limiting embodiment, the conveying device is adapted to advance tube3and any intermediate of tube3in a manner known as such along the tube advancement path, in particular from tube forming station23towards and at least partially through package forming unit26. In particular, with intermediates of tube3any configuration of web4is meant prior to obtaining the tube structure and after folding of web4by the tube forming device has started. In other words, the intermediates of tube3are a result of the gradual folding of web4so as to obtain tube3, in particular by overlapping opposite lateral edges of web4with one another.

With particular reference toFIG. 1, isolation chamber5comprises an inlet opening31configured to allow, in use, (the sterilized) web4to enter into isolation chamber5, in particular inner environment6, and an outlet opening32configured to allow, in use, the outlet of tube3from isolation chamber5, in particular inner environment6.

With particular reference toFIG. 1, sterilization apparatus8further comprises:an irradiation device33arranged in the area of, in particular at, the sterilization station and within sterilization chamber10, even more particular within inner space11, and being configured to sterilize at least the first face, preferentially also the second face, of web4by directing a sterilizing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, onto at least the first face, preferentially also onto the second face, while, in use, web4advances along a sterilization portion of the web advancement path.

According to a preferred non-limiting embodiment, sterilization chamber10is arranged upstream of isolation chamber5along the web advancement path. In particular, in use, web4advances from inner space11into inner environment6(i.e. inner environment6receives web4after its sterilization).

According to a preferred non-limiting embodiment, sterilization chamber10comprises an inlet passage34and an outlet passage35configured to allow respectively the entrance and the exit of web4into and from sterilization chamber10, in particular inner space11.

According to a preferred non-limiting embodiment, isolation chamber5and sterilization chamber10are connected to one another, in particular such that inlet opening31and outlet passage35are adjacent to one another. In other words, in use, (the sterilized) web4exits from sterilization chamber10and enters directly into isolation chamber5.

With particular reference toFIG. 1, the tube forming device comprises at least a first forming ring assembly and a second forming ring assembly, in particular arranged within isolation chamber5, even more particular within inner environment6, and being adapted to gradually fold in cooperation with one another web4into tube3, in particular by overlapping the edges of web4with one another for forming the longitudinal seam portion.

Even more particular, the first forming ring assembly and the second forming ring assembly are spaced apart from and parallel to one another.

Furthermore, the first forming ring assembly and the second forming ring assembly are arranged coaxial to one another and define the longitudinal axis of the tube forming device.

According to a preferred non-limiting embodiment, the sealing device comprises a sealing head arranged within isolation chamber5, in particular inner environment6, and being adapted to (configured to) transfer thermal energy to tube3, in particular to the seam portion for longitudinally sealing tube3, in particular the seam portion. The sealing head can be of any type. In particular, the sealing head can be of the kind operating by means of induction heating and/or by a stream of a heated gas and/or by means of ultrasound and/or by laser heating and/or by any other means.

Preferentially but not necessarily, the sealing device also comprises a pressing assembly adapted to exert a mechanical force on tube3, in particular onto the seam portion, so as to ensure the longitudinal sealing of tube3along the seam portion. In particular, the pressing assembly comprises at least an interaction element (not shown) and a counter-interaction element (not shown) adapted to exert the mechanical force onto the seam portion from opposite sides thereof.

Preferentially but not necessarily, the sealing head is arranged between the first forming ring assembly and the second forming ring assembly.

With particular reference toFIG. 1, filling device25comprises a filling pipe39being in fluid connection with a pourable product supply (not shown) and being adapted to (configured to) direct, in use, the pourable product into tube3.

Preferentially but not necessarily, filling pipe39is, in use, at least partially placed within tube3for feeding the pourable product into tube3.

According to a preferred non-limiting embodiment as shown inFIG. 1, package forming unit26comprises a plurality of pairs of at least one respective operative assembly40and at least one counter-operative assembly41(only partially shown to the extent necessary for the understanding of the present invention); andin particular, a conveying device (not shown and known as such) adapted to advance the respective operative assemblies40and the respective counter-operative assemblies41of the pairs along respective conveying paths.

In more detail, each operative assembly40is configured to cooperate, in use, with the respective counter-operative assembly41of the respective pair for forming a respective package2from tube3. In particular, each operative assembly40and the respective counter-operative assembly41are configured to form, to transversally seal and, preferably but not necessarily also to transversally cut, tube3for forming packages2.

With particular reference toFIGS. 1 and 2, conduct assembly15comprises at least one main injection portion45configured to introduce and/or inject gas flowing, in use, within the flow circuit, in particular conduct assembly15, into isolation chamber5, in particular inner environment6.

According to the non-limiting embodiment shown, injection portion45extends within inner environment6.

Alternatively, injection portion45could be connected to isolation chamber5without extending within inner environment6.

According to a non-limiting embodiment, conduct assembly15also comprises at least an auxiliary injection portion46configured to introduce and/or inject gas flowing, in use, within the flow circuit, in particular conduct assembly15, into an interface area between isolation chamber5and sterilization chamber10.

According to a non-limiting embodiment, conduct assembly15also comprises at least a first valve47configured to selectively control the outflow of gas through main injection portion45, and in particular also at least a second valve48configured to control the outflow of gas through auxiliary injection portion46.

According to a preferred non-limiting embodiment, conduct assembly15comprises an inlet portion49configured to receive gas flowing, in use, from inner space11into conduct assembly15. In particular, inlet portion49is connected to sterilization chamber10.

According to a preferred non-limiting embodiment, conduct assembly15also comprises a main conduct portion50connected to inlet portion49and main injection portion45and/or auxiliary injection portion46. In particular, main conduct portion50fluidically connects main injection portion45and/or auxiliary injection portion46with inlet portion49.

With particular reference toFIG. 1, nitrogen distribution unit16comprises at least a nitrogen generator51configured to generate nitrogen, in particular from air. Preferentially but not necessarily, nitrogen distribution unit16also comprises a nitrogen storage tank52configured to store and/or buffer nitrogen generated by nitrogen generator51.

According to a preferred non-limiting embodiment, nitrogen distribution unit16also comprises a flow control assembly53configured to control the injection and/or inlet of the nitrogen into the flow circuit, in particular into conduct assembly15. Preferentially but not necessarily, flow control assembly53is also configured to control the flow rate of the nitrogen being, in use, introduced and/or injected by nitrogen distribution unit16, in particular so that the flow rate ranges between 1 to 20 m3/h, even more particular between 3 to 10 m3/h.

According to a preferred non-limiting embodiment, nitrogen distribution unit16is operationally connected to the control device.

With particular reference toFIG. 1, flow controlling device18comprises a rotary machine54, in particular a compressor, even more particular a dry-type compressor, being arranged within conduct assembly15, in particular main conduct portion50, and being configured to generate the flow of gas along flow path Q. In particular, rotary machine54exerts a suction force within inner space11so as to extract gas from inner space11and to direct gas, in particular through main injection portion45, into inner environment6.

According to a preferred non-limiting embodiment, rotary machine54is also configured to direct the nitrogen injected and/or introduced by nitrogen distribution unit16into at least isolation chamber5, in particular inner environment6.

Preferentially but not necessarily, rotary machine is positioned downstream of injection station17along flow path Q.

According to a preferred non-limiting embodiment, flow controlling device18is operationally connected to the control device.

According to a preferred non-limiting embodiment, control valve19is operationally connected to the control device.

According to a preferred non-limiting embodiment, control valve19is controllable, in particular by the control device, so as to at least selectively open and close for respectively allowing or impeding the evacuation and/or release of gas from the flow circuit (and through control valve19).

Preferentially but not necessarily, control valve is of the three-way type and is integrated into conduct assembly15, in particular main conduct portion50.

Preferentially but not necessarily, control valve is configured to allow a fluid connection between inlet portion49and at least main injection portion45, in particular also auxiliary injection portion46, when being opened and when being closed.

According to a preferred non-limiting embodiment, packaging machine1also comprises a pressure control assembly57configured to control the pressure within at least isolation chamber5, and in particular also within sterilization chamber10, in particular such that the pressure is above the ambient pressure, even more particular controlling an overpressure of 20 Pa or more.

Preferentially but not necessarily, pressure control assembly57is configured to control the pressure and/or the flow rate of the gas to be introduced into inner environment6and/or inner space11.

According to a preferred non-limiting embodiment, at least a portion of pressure control assembly57is arranged downstream of rotary machine54and upstream of isolation chamber5along flow path Q.

According to a preferred non-limiting embodiment, packaging machine1also comprises a gas sterilization assembly58configured to sterilize and/or purify the gas to be introduced and/or inserted into inner environment6. In particular, gas sterilization assembly58is integrated into conduct assembly15and arranged upstream of isolation chamber5and/or inner environment6along flow path Q. Preferentially but not necessarily, gas sterilization assembly58is arranged downstream of rotary machine54along flow path Q.

According to a preferred non-limiting embodiment, gas sterilization assembly58comprises at least a main sterilization portion59(comprising a plurality of gas filters) and, preferentially but not necessarily a pre-sterilization portion60arranged upstream of main sterilization portion59along flow path Q.

According to a preferred non-limiting embodiment, packaging machine1also comprises a heating unit61configured to heat the gas flowing along flow path Q. In particular, heating unit61is arranged downstream from rotary machine54and upstream of isolation chamber5, along flow path Q.

Preferentially but not necessarily, heating unit61is arranged upstream of main sterilization portion59along flow path Q; and in particular downstream form pre-sterilization portion60along flow path Q.

According to a preferred non-limiting embodiment, packaging machine1also comprises an air distribution unit62configured to at least distribute air to nitrogen distribution unit16, in particular nitrogen generator51.

Preferentially but not necessarily, air distribution unit62comprises at least an air compressor and an air filter assembly.

Preferentially but not necessarily, air distribution unit62is also configured to selectively introduce and/or inject air into the flow circuit, in particular into conduct assembly15at an air inlet station63, in particular downstream of control valve19along flow path Q.

Preferably but not necessarily, air distribution unit62also comprises an air flow control assembly64configured to control the injection and/or inlet of the air into the flow circuit, in particular into conduct assembly15.

According to a preferred non-limiting embodiment, air distribution unit62is operationally connected to the control device.

According to a preferred non-limiting embodiment, the control device is configured to control packaging machine1at least into:an operative configuration in which packaging machine1produces, in use, packages2; anda set-up configuration in which packaging machine is prepared so as to obtain the desired and/or required conditions within at least inner environment6and inner space11.

Preferentially but not necessarily, the control device is also configured to control packaging machine1into a venting configuration during which packaging machine1is vented, in particular such that inner environment6and/or inner space11is/are filled with air.

According to a preferred non-limiting embodiment, in use, packaging machine1is controlled into the set-up configuration for controlling and/or determining a defined gas atmosphere within inner environment6and/or inner space11.

According to a preferred non-limiting embodiment, the control device is configured to control packaging machine1into the set-up configuration so as to control and/or determine the gas atmosphere within inner environment6and/or inner space11and/or the gas flowing along flow path Q. In particular, the control device controls packaging machine1in the set-up configuration for obtaining a nitrogen content of the gas within inner environment6and/or inner space11and/or the gas flowing along flow path Q being at least volume %, in particular being at least 95 volume %, even more particular substantially equaling 99 volume %. According to a preferred non-limiting embodiment, the control device is configured to control, in particular when packaging machine1is, in use, controlled into the set-up configuration, control valve19so as to selectively open and close control valve19for respectively allowing or impeding the evacuation and/or release of gas from the flow circuit (and through control valve19) as a function of the nitrogen and/or oxygen content within the flow of gas, in use, along flow path Q and as determined and/or measured by gas sensor21. In particular, the control device is configured to close control valve19if the flow of gas within flow circuit and/or the gas being within inner environment6and/or within inner space11corresponds to a pre-determined and/or desired and/or required condition, in particular having the desired nitrogen content. In this way, it is guaranteed that the formation of package2and/or the sterilization of web4can be performed within a substantially nitrogen atmosphere.

In use, packaging machine1forms packages2filled with the pourable product.

According to a preferred non-limiting embodiment, packaging machine1forms packages2while being controlled, in particular by the control device, into the operative configuration.

According to a preferred non-limiting embodiment, packaging machine1is, in particular prior to being controlled into the operative configuration, controlled into the set-up configuration, so as to control the gas atmosphere within inner environment6and/or inner space11and/or of the gas flowing along flow path Q.

According to a preferred non-limiting embodiment, packaging machine1is, in particular after having been controlled in the operative configuration, controlled in the vent configuration, so as to allow a venting of at least inner environment6and/or inner space11and/or conduct assembly15, in particular so as to exchange the gas present with air.

Advantageously, a method for forming packages2comprises at least the steps of:controlling the flow of gas along flow path Q within the flow circuit; andcontrolling the gas content of the gas flowing within the flow circuit and/or of the gas present within inner environment6and/or the gas present within inner space11by introducing nitrogen into the flow circuit at injection station17.

According to a preferred non-limiting embodiment, the step of controlling the gas content is executed with packaging machine1being controlled in the operative configuration or the set-up configuration.

Preferentially but not necessarily, during the step of controlling the gas content, nitrogen distribution unit16directs the nitrogen into the flow circuit. In particular, flow control assembly53controls and/or determines the flow of nitrogen into the flow circuit, even more particular so that the flow rate ranges between 1 to 20 m3/h, most preferably between 3 to 10 m3/h.

Preferentially but not necessarily, during the step of controlling the gas content, the volume ratio of the nitrogen within inner environment6and/or inner space is controlled to be at least 90 volume %, in particular being at least 95 volume %, even more particular substantially equaling 99 volume %.

Preferentially but not necessarily, during the step of controlling the gas content, in particular, with packaging machine1being controlled in the operative configuration, the flow of the nitrogen is controlled such that the volume of the introduced nitrogen compensates for any gas, in particular any nitrogen, being lost from the flow circuit.

According to a preferred non-limiting embodiment, during the step of controlling the flow of gas, gas flows from inner environment6through at least a portion of conduct assembly15back into inner environment6. Preferentially but not necessary, the gas flows from inner environment6to inner space11and from inner space11into inner environment6through at least a portion of conduct assembly15.

According to a preferred non-limiting embodiment, rotary machine54creates a suction force on the gas present within inner space11and directs the gas through main injection portion45into inner environment6.

Preferentially but not necessarily, during the step of controlling the flow of gas, the gas flows through at least gas sterilization assembly58, in particular main sterilization portion59and/or pre-sterilization portion60, and/or heating unit61.

According to a preferred non-limiting embodiment, the method also comprises the step of producing nitrogen, during which nitrogen generator51produces nitrogen, in particular by extracting nitrogen from air. Preferentially but not necessarily, during the step of producing nitrogen, nitrogen generator51receives air from air distribution unit62.

According to a preferred non-limiting embodiment, the method also comprises a step of evacuating and/or releasing gas from the flow circuit through control valve19. Preferentially but not necessarily, the step of evacuating and/or releasing gas is executed with packaging machine1being controlled, in particular by the control device, in the set-up configuration or the venting configuration.

Preferentially but not necessarily, during the step of evacuating and/or releasing, control valve19is selectively opened for allowing the evacuation and/or release of the gas (through control valve19) and is selectively closed for impeding the evacuation and/or release of the gas (through control valve19). In particular, control valve19is controlled, in particular when packaging machine1is controlled in the set-up configuration, as a function of the oxygen and/or nitrogen content within the gas flowing along flow path Q.

Preferentially but not necessarily, during the step of evacuating and/or releasing and with packaging machine1being controlled into the set-up configuration, control valve19is opened until the nitrogen content within the gas flowing along flow path is at least 90 volume %, in particular at least 95 volume %, even more particular at least 99 volume %.

Preferentially but not necessarily, with packaging machine1being controlled into the venting configuration control valve19is opened.

According to a preferred non-limiting embodiment, the method also comprises the step of determining and/or measuring, in particular by means of gas sensor21, the nitrogen and/or oxygen content within the gas flowing along flow path Q.

According to a preferred non-limiting embodiment, the method also comprises a step of controlling the gas pressure within at least isolation chamber5and/or sterilization chamber10.

Preferentially but not necessarily, the step of controlling the gas pressure is executed with packaging machine1being controlled in the operative configuration or the set-up configuration.

Preferentially but not necessarily, during the step of controlling the gas pressure, pressure control assembly57controls the pressure within inner environment6and/or inner space11to be above ambient pressure, in particular so that there is an over-pressure of at least 20 Pa.

According to a preferred non-limiting embodiment, the method also comprises the step of sterilizing the gas flowing along flow path Q, in particular by means of gas sterilization assembly58.

Preferentially but not necessarily, during the step of sterilizing, the gas is sterilized by gas sterilization assembly58, in particular by at least main sterilization portion59and, even more particular also by pre-sterilization portion60.

According to a preferred non-limiting embodiment, the method also comprises the step of directing air into the flow circuit, in particular into conduct assembly15. Preferentially but not necessarily, the step of directing air, is executed with packaging machine1being controlled, in particular by the control device, into the venting configuration.

According to a preferred non-limiting embodiment, the steps of advancing web4and/or of forming tube3and/or of longitudinally sealing tube3and/or of filling tube3and/or of obtaining single packages is/are executed with packaging machine1being controlled, in particular by the control device, in the operative configuration.

According to a preferred non-limiting embodiment, during the step of advancing web4, the conveying device advances web4along the web advancement path through sterilization apparatus8, in particular through inner space11, and into isolation chamber5, in particular inner environment6. In particular, the conveying device advances the sterilized web4to the tube forming device so as to form tube3. In other words, the conveying device advances web4to sterilization station9and to tube forming station23.

According to a preferred non-limiting embodiment, during the step of longitudinally sealing tube3, the sealing device, in particular the sealing head, heats and/or directs thermal energy to the seam portion.

According to a preferred non-limiting embodiment, during the step of advancing tube3, the conveying device advances tube3(and any intermediates of tube3) along the tube advancement path to (and partially through) package forming unit26.

According to a preferred non-limiting embodiment, during the step of filling tube3, filling device25fills the pourable product into the longitudinally sealed tube3. In particular, the pourable product is directed into tube3through filling pipe39.

According to a preferred non-limiting embodiment, during the step of obtaining single packages2, package forming unit26, in particular the operative assemblies40and the respective counter-operative assemblies40, at least forms and transversally seals tube3between successive packages2and, preferentially, also transversally cuts tube3between successive packages2.

According to a preferred non-limiting embodiment, during the step of sterilizing web4, at least a sterilizing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, is directed onto at least the first face, preferentially also onto the second face6, of web.

The advantages of packaging machine1and the method for producing packages2according to the present invention will be clear from the foregoing description.

In particular, packaging machine1allows to obtain a nitrogen atmosphere within inner environment6and/or inner space11allowing to form and fill tube3and/or to sterilize web4in an inert gas atmosphere. With regard to the sterilization of web4, this allows to avoid the formation of unwanted substances, in particular in the case of using an irradiation. With regard to the forming and filling of tube3, this allows to avoid any oxidation processes or to provide for the nitrogen needed in the case of producing packages2with a nitrogen headspace.

Clearly, changes may be made to packaging machine1and/or the method as described herein without, however, departing from the scope of protection as defined in the accompanying claims.

According to an alternative embodiment not shown, nitrogen distribution unit16is fluidically connected to a centralized nitrogen supply of e.g. the production facility within which packaging machine1is installed. According to such an alternative embodiment, nitrogen distribution unit16does not necessarily comprises nitrogen generator51and/or nitrogen storage tank52.