TECHNICAL FIELD

The present invention relates to a packaging machine for forming packages filled with a pourable food product from a web of packaging material, in particular a web of packaging material having a multilayer structure. The packaging machine comprises a molding apparatus for molding molded portions, in particular opening devices, onto the web of packaging material.

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 a laminated packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. of paper or cardboard, 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 oxygenbarrier material (an oxygen-barrier layer) , e.g. an aluminum foil, which is superimposed on a layer of heatseal 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 apparatuses, which advance and sterilize a web of packaging material, which is then formed into a tube and filled with the pourable pre/ sterili zed product under aseptic conditions before its formation into individual sealed packages .

It is known that some types of packages also comprise respective opening devices , which allow to be manipulated for accessing the pourable product .

In order to provide the packages with the opening devices , some automatic packaging apparatuses also comprise a molding apparatus for molding the opening devices onto the web of packaging material prior to the formation of the packages .

It is furthermore known that the automatic packaging apparatus may comprise an isolation chamber within which the web of packaging material is formed and filled with the pourable product . As the web of packaging material gets into contact with the pourable product one needs to guarantee the cleanliness and/or sterility of the isolation chamber and of the web of packaging material .

Therefore , the typical automatic packaging apparatuses also comprise a sterili zation apparatus arranged downstream of the molding apparatus and upstream of the isolation chamber so as to sterili ze the packaging material .

It should be noted that the known sterili zation apparatuses can be configured to sterili ze the web of packaging material by means of chemical sterili zation or by physical sterili zation .

In the recent years , the Applicant has success fully established the use of the electron beam technology so as to sterili ze the web of packaging material . While the sterili zation of the flat web of packaging material by means of the electron beam technology is relatively easy, the situation becomes more challenging in the case of the presence of opening devices , which have been applied onto the web of packaging material . When sterili zing the web of packaging material being equipped with the opening devices , one may need to operate with rather high powers so as to obtain the desired sterility .

Thus , even though, the known packaging machine achieve excellent working results , a desire is felt in the sector to further improve the known packaging machines .

DISCLOSURE OF INVENTION

It is an obj ect of the present invention to provide in a straightforward and low-cost manner an improved packaging machine having a molding apparatus .

It is a further obj ect of the present invention, to provide in a straightforward and low-cost manner an improved method for forming packages filled with a pourable food product from a web of packaging material .

According to the present invention, there is provided a packaging machine as claimed in claim 1 and a method as claimed in claim 12 .

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

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawing, in which :

Figure 1 is a schematic view of a packaging machine according to the present invention, with parts removed for clarity .

BEST MODES FOR CARRYING OUT THE INVENTION

Number 1 indicates as a whole a packaging machine for producing ( sealed) packages 2 of a pourable food product such as pasteuri zed milk, fruit j uice , wine , tomato sauce , emulsions , beverages with pulp etc .

Each packaging 2 may comprise a main body 3 and a molded portion 4 , in particular an opening device , molded onto main body 3 .

In particular, packaging machine 1 may produce packages 2 , in particular the respective main bodies 3 , from a web of packaging material 5 .

In more detail , web of packaging material 5 may have a multilayer structure and may comprise 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 package 2 eventually contacting the pourable product .

Moreover, web of packaging material 5 also 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 .

Additionally, web of packaging material 5 may also comprise a further layer of heat-seal plastic material being interposed between the layer of gas- and lightbarrier material and the layer of fibrous material .

Web of packaging material 5 may comprise a first face and a second face , in particular the first face being the face of web of packaging material 5 defining the inner face of the formed package 2 eventually contacting the filled pourable food product .

Preferentially, web of packaging material 5 may comprise a plurality of repeat units , in particular successively arranged ( and equally spaced) with respect to one another along web of packaging material 5 . In particular, each repeat unit may form the basis of one respective package 2 . In other words , packaging machine 1 may be configured to produce packages 2 from web of packaging material 5 such that each package 2 results from one respective repeat unit .

In particular, each repeat unit may be defined by one respective pattern present on web of packaging material 5 . Even more particular, the pattern is substantially identical for all repeat units and may also di f fer in minor details from the other ones - minor di f ferences may e . g . be the presence of information tags indicating a production day, a production lot , personali zed information or similar .

With particular reference to Figure 1 , packaging machine 1 comprises :

- a conveying device 6 configured to advance web of packaging material 5 along a web advancement path P ;

- a molding apparatus 7 arranged at a molding station 8 for molding molded portions 4 , in particular the opening devices , onto web of packaging material 5 ;

- a sterili zation apparatus 9 for sterili zing web of packaging material 5 and being arranged at a sterili zation station 10 downstream of molding station 8 along web advancement path P ;

- an isolation chamber 15 having an inner environment 16 ;

- a tube forming and sealing device 17 configured to form a tube 18 from the , in use , advancing web of packaging material 5 and to longitudinally seal tube 18 within inner environment 16 at a tube formation station 19 positioned upstream of steri li zation station 10 along web advancement path P ; - a filling device 20 configured to fill tube 18 with the pourable food product ; and

- a package forming apparatus 21 configured to at least form and transversally seal tube 18 , preferentially to also transversally cut tube 18 , for forming ( sealed) packages 2 .

The Applicant has seen that after termination of the molding process , molded portions 4 are clean and/or sterile as a consequence of a number of factors including the high temperatures of plastic processing conditions needed during the molding proces s itsel f . Therefore , the Applicant wants to preserve (partially or in full ) the cleanliness and/or sterility of molded portions 4 during advancement of web of packaging material 5 from molding station 8 to sterili zation station 10 .

Therefore , packaging machinel also comprises a preserving device 22 configured to preserve the cleanliness and/or sterility of molded portions 4 , in particular opening devices , in particular after molding .

In particular, preserving device 22 is configured to preserve the cleanliness and/or sterility of molded portions 4 , in particular opening devices , during advancement of web of packaging material 5 between molding station 8 and sterili zation station 10 .

In this way, one facilitates the operation of sterili zation apparatus 9 .

According to some preferred non-limiting embodiments , molding apparatus 7 molds at least one respective molded portion 4 , in particular one respective opening device , onto each repeat unit of web of packaging material 3 .

In particular, molding apparatus 7 is configured to mold molded portions 4 from a molten polymer . In the most preferred embodiment , molding apparatus 7 molds opening devices onto web of packaging material 3 .

In particular, each opening device may be configured to allow to access and/or to outpour, in particular after a manipulation of the opening device , the pourable food product packaged within the respective package 2 . In particular, the manipulation of the opening device can be reversible or irreversible .

One example of an opening device is a lid-spout assembly, which comprises a spout and a lid, which is configured to selectively close and open a pouring outlet of the spout . In order to access and/or outpour the pourable product from packages 2 being provided with such an opening device removal of the lid is required, which typically is reversible , meaning that the lid can be newly coupled to the spout .

Another example of an opening device is a strip, which can be removed from the respective package 2 for creating an outlet hole and/or for allowing to at least partially separating two portions of the respective package 2 from one another .

In further detai l , molding apparatus 7 may comprise one or more molding units 11 each one configured to mold one or more molded portions 4 , in particular one or more opening devices ( at a time ) onto web of packaging material 5 , in particular onto at least one respective repeat unit .

According to some possible non-limiting embodiments , molding apparatus 7 may comprise one or more punching units configured to punch holes in web of packaging material 5 , in particular prior to the operation of the one or more molding units 11 . In other words , the punching unit may be arranged upstream of molding apparatuses 20 along web advancement path P . In particular, the one or more molding units 11 may be configured to mold molded portions 4 , in particular the opening devices , onto web of packaging material 5 at the holes .

Advantageously, conveying device 6 may also be configured to advance tube 18 along a tube advancement path Q towards and at least partially through package forming apparatus 21 .

In further detail , conveying device 6 may also be configured to advance tube 18 and any intermediate of tube 18 along tube advancement path Q . In particular, with intermediates of tube 18 any configuration of web of packaging material 5 is meant prior to obtaining the tube structure and after folding of web of packaging material 5 has been started . In other words , the intermediates of tube 18 are a result of a gradual folding of web of packaging material 5 so as to obtain tube 18 , in particular by overlapping opposite lateral edges of web of packaging material 5 with one another .

Preferentially, conveying device 6 may also be configured to advance web of packaging material 5 at and/or within molding apparatus 7 intermittently .

Even more preferentially, conveying device 6 may be configured to intermittently advance and stop web of packaging material 5 , and in particular each molding unit 11 may be configured to mold the respective molded portions 4 during a stop of web of packaging material 5 .

Preferentially, conveying device 6 may be configured to intermittently advance web o f packaging material 5 along a molding portion Pl of path P .

Advantageously, packaging machine 1 may also comprise a first buf fer unit and a second buf fer unit 24 arranged respectively upstream and downstream of molding station 8 along web advancement path P .

Preferentially, the buf fer capacity of the first buf fer unit and second buf fer unit 24 can be ( dynamically) varied .

Moreover, conveying device 6 may be configured to advance web of packaging material 5 to first buf fer unit and withdraw web of packaging material 5 from second buf fer unit 24 in a continuous manner .

In this way, one guarantees a continuous production of packages 2 while allowing an intermittent operation of molding apparatus 7 .

With particular reference to Figure 1 , isolation chamber 15 is configured to protect inner environment 16 from an (hostile ) outer environment .

Even more particular, isolation chamber 15 is configured to allow for forming, longitudinally sealing and filling tube 18 in a sterile inner environment 16 .

Preferentially, packaging machine 1 may also comprise a conditioning unit configured to define and control the atmosphere and conditions within inner environment 16 . In particular, the conditioning unit may be configured to maintain and control sterility of inner environment 16 . Additionally, the conditioning unit may also be configured to control temperature and/or humidity and/or pressure .

Moreover, the conditioning unit may also be configured to maintain sterility within inner environment 16 .

Preferentially, prior to operation of packaging machine 1 , inner environment 16 is subj ected to a sterili zation process , in particular a chemical and/or physical sterili zation process , so as to establish sterility of inner environment 16 . In particular, a sterili zation-in-place ( S IP ) may be executed .

With particular reference to Figure 1 , sterili zation apparatus 9 may comprise an irradiation device 30 configured to direct a sterili zing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, onto the , in use , advancing web of packaging material 5 . In particular, irradiation device 30 may be configured to direct the sterili zing irradiation onto the f irst face and the second face of web of packaging material 5 .

In further detail , irradiation device 30 may comprise one or more e-beam emitters for emitting electron beam irradiation onto the , in use , advancing web of packaging material 5 , in particular onto the first face and the second face .

More precisely, irradiation device 30 may comprise a pair of e-beam emitters , in particular a first e-beam emitter 31 and a second e-beam emitter 32 . Moreover, first e-beam emitter 31 and second e-beam emitter 32 are spaced apparat from one another such that , in use , the advancing web of packaging material 5 advances between first e-beam emitter 31 and second e-beam emitter 32 . In particular, first e-beam emitter 31 and second e-beam emitter 32 are arranged such to direct the electron beam irradiation onto respectively the first face and the second face .

Alternatively, sterili zation apparatus 9 could be configured to sterili ze web of packaging material 5 by chemical sterili zation .

Advantageously, sterili zation apparatus 9 may comprise a housing 33 having an inlet opening for receiving web of packaging material 5 to be sterili zed and an outlet opening for allowing feeding out of the sterili zed web of packaging material 5 . Preferentially, the outlet opening may be adj acent to an inlet aperture of the isolation chamber 15 such that web of packaging material 5 exits , in use , steri li zation apparatus 9 through the outlet opening and enters , in use , the isolation chamber 15 through the inlet aperture .

With particular reference to Figure 1 , packaging machine 1 may comprise a further housing (not shown) delimiting an inner space within which molding apparatus 7 is arranged and/or within which web of packaging material 5 advances , in use , along advancement path P, in particular between at least molding station 8 and sterili zation station 10 .

Advantageously, preserving device 22 comprises at least one blowing unit 39 configured to generate a flow of sterile fluid, in particular of sterile gas such as sterile air, and direct the flow of sterile fluid against at least a portion of web of packaging material 5 while web of packaging material 5 advances between molding station 8 and sterili zation station 10 .

Preferentially, the portion of web of packaging material 5 that receives the flow of sterile fluid is intended with regard to the relative position between molding station 8 and sterili zation station 10 .

In particular, by providing for blowing unit 39 and the generation of the flow of sterile fluid against web of packaging material 5 , one achieves that the deposition of possible contaminants on web of packaging material 3 and molded portions 4 is hampered, which again renders the sterili zation by means of sterili zation apparatus 9 easier . In particular, the inner space is not a sterile space , i . e . the inner space i s not part of inner environment 16 .

Preferentially, preserving device 22 may compri se more than one blowing unit 39 , each one configured to generate a respective flow of sterile fluid, in particular of sterile gas such as sterile air, against at least a portion of web of packaging material 5 while advancing along a respective portion of web advancement path P and between molding station 8 and sterili zation station 10 .

More speci fically, each blowing unit 39 may be positioned at a respective position di f ferent from the position of the other blowing units 39 so as to direct the respective flow of sterile fluid onto di f ferent portions of web of packaging material 5 . In particular, each blowing unit 39 may be arranged at respective positions along web advancement path P between molding station 8 and sterili zation station 10 , in particular such that one or more blowing units 39 may be placed at upstream positions between molding station 8 and sterili zation station 10 and with regard to web advancement path P and one or more other blowing units 39 may be positioned at downstream positions between molding station 8 and sterili zation station 10 and with regard to web advancement path P ( i . e . one or more blowing units 39 may be arranged upstream of one or more other blowing units 39 ) .

Preferentially, the at least one flow of sterile fluid and/or the plurality of flows of sterile fluid may be directed onto the first face and the second face of web of packaging material 5 . This allows to preserve the cleanliness and/or sterility of the respective zones of molded portions 4 which are accessible from the first face and the second face , respectively .

According to some possible embodiments , each blowing unit 39 may also be configured to generate two respective flows of sterile fluid . Thereby, a first flow of sterile fluid and a second flow of sterile fluid may be directed towards the first face and the second face , respectively .

According to some preferred non-limiting embodiments , each blowing unit 39 may be configured to generate a flow of sterile fluid in a direction DI transversal and/or opposite to an advancement direction D2 of web of packaging material 5 . In particular , each advancement direction D2 is the respective direction of advancement of web of packaging material 5 at the respective portion onto which the respective flow of sterile fluid is directed onto .

It should be noted that advancement direction D2 may locally vary and accordingly, the respective directions DI of blowing units 39 may di f fer from one another in dependence of the local advancement direction D2 .

In a most preferential embodiment , each blowing unit 39 may be configured to generate the flow of sterile fluid such that the respective direction DI is oppos ite to advancement direction D2 .

It may be possible that an angle defined between directions DI and the respective advancement directions D2 may vary . In other words , blowing units 39 may be configured such that at least one or more blowing units 39 may generate the respective flow of sterile fluid such that the angle defined with the respective advancement directions D2 may vary with regard to the respective angles defined by the respective flows of sterile fluid and the respective advancement directions D2 .

Advantageously, preserving device 22 may also comprise one or more disinfection units for disinfecting at least portions , in particular molded portions 4 , of web of packaging material 5 while advancing between molding station 8 and sterili zation station 10 . Disinfection unit may comprise one or more UV-light emitters .

In more detail and with reference to Figure 1 , tube forming and sealing device 17 may comprise at least two forming ring assemblies 45 , in particular arranged within inner environment 16 , being configured to gradual ly fold in cooperation with one another web of packaging material 5 into tube 18 , in particular by overlapping the edges of web of packaging material 5 with one another .

Additionally, tube forming and sealing device 17 may comprise a sealing head 46 , in particular arranged within inner environment 16 and, configured to longitudinally seal tube 18 .

Additionally, filling device 20 may comprise a filling pipe 47 being configured to direct , in use , the pourable product into tube 18 . In particular, filling pipe 47 may, in use , be at least partially placed within tube 18 for feeding, in use , the pourable product into tube 18 .

Moreover, package forming apparatus 21 may comprise :

- a plurality of forming and sealing assemblies , each one configured to at least form ( shape ) tube 18 , to transversally seal tube 18 , and in particular to also transversally cut tube 18 ; and

- a conveying unit so as to advance the forming and sealing assemblies .

In particular, package forming apparatus 12 is configured to control the forming and sealing as semblies and the conveying unit such to transversally seal and cut tube 18 along equally spaced transversal cross sections .

In use , packaging machine 1 produces packages 2 of a pourable food product . In particular, packaging machine 1 forms tube 18 from web of packaging material 5 , longitudinally seals tube 18, fills tube 18 with the pourable product and forms, transversally seals and transversally cuts tube 18 so as to obtain packages 2.

Prior to the formation of tube 18 from web of packaging material 5, web of packaging material 5 is sterilized by sterilization apparatus 9.

Additionally, prior to the sterilization, molding apparatus 7 molds molded portions 4, in particular the opening devices, onto web of packaging material 5, in particular the respective repeat units.

In more detail, operation of packaging machine 1 comprises the following steps:

- advancing, in particular by means of conveying device 6, web of packaging material 5 along web advancement path P; molding, in particular by means of molding apparatus 7, molded portions 4 onto web of packaging material 5 at molding station 8; sterilizing, in particular by means of sterilization apparatus 9, web of packaging material 5 at sterilization station 10;

- forming, in particular by means of tube forming and sealing device 17, tube 18 from the, in use, advancing web of packaging material 5 within inner environment 16;

- longitudinally sealing tube 18, in particular by means of tube forming and sealing device 17, within inner environment 16;

- filling tube 18, in particular by means of filling device 20, with the pourable food product; producing, in particular by means of package forming apparatus 21, packages 2 from tube 18 by forming, transversally sealing, and transversally cutting tube 18; and - preserving the cleanliness and/or sterility of at least molded portions 4 .

Additionally, operation of packaging machine 1 may also comprise the step of conveying tube 18 along tube advancement path Q .

Preferentially, operation of packaging machine 1 may also comprise a first step of buf fering, executed by first buf fer unit and a second step of buf fering executed by second buf fer unit 24 .

During the step of preserving, the flow of sterile fluid is directed against at least a portion, in particular at least against molded portions 4 , of web of packaging material 5 while web of packaging material 5 advances between molding station 8 and sterili zation station 10 . In particular, the flow of sterile fluid may be generated by the at least one blowing unit 39 .

Preferentially, during the step of preserving, a plurality of flows of sterile fluid are generated . In particular each blowing unit 39 generates one respective flow of sterile fluid .

Moreover, each f low of sterile f luid, in particular as generated by the respective blowing units 39 , may be directed against a respective portion distinct from the other portions of web of packaging material 5 while web of packaging material 5 advances along a respective portion of web advancement path P and while web of packaging material 5 advances between molding station 8 and sterili zation station 10 .

Preferentially, during the step of preserving, each flow of sterile fluid is such that the respective directions DI are transversal and/or opposite to the respective advancement direction D2 of the web of packaging material 5 ( in particular at the speci fic location) .

Additionally, each flow of sterile fluid is directed onto one of the first face and the second face or onto both the first face and the second face . Preferentially, the overall flows of sterile fluid are such that at least one flow of sterile fluid is directed onto the first face and at least one flow of sterile fluid is directed onto the second face .

According to some possible non-limiting embodiments , during the step of preserving, a sub-step of disinfecting is executed during which at least portions , in particular molded portions 4 , of web of packaging material 5 are disinfected while web of packaging material 5 advances between molding station 8 and sterili zation station 10 .

In particular, during the sub-step of disinfecting a UV-irradiation is directed onto web of packaging material 5 , in particular onto the first face and/or the second face .

In more detail , during the step of advancing, web of packaging material 5 is intermittently advanced at molding station 8 and/or within molding apparatus 7 .

In particular, during the step of advancing, web of packaging material 5 is intermittently advanced between first buf fer unit and second buf fer unit 24 .

Moreover, during the step of advancing, web of packaging material 5 is advanced along web advancement path P .

In more detail , during the step of molding, molding apparatus 7 molds molded portion 4 , in particular the opening devices , onto web of packaging material 5 .

In particular, during the step of molding, advancement of web of packaging material 5 at molding station 8 and/or within molding apparatus 7 is on halt . In more detail , during the step of sterili zing, the sterili zing irradiation, in particular the electromagnetic irradiation, even more particular the electron beam irradiation, is directed onto web of packaging material 5 , in particular onto the first face and the second face .

The advantages of packaging machine 1 and/or the method according to the present invention will be clear from the foregoing description .

In particular, by having preserving device 22 it is possible to maintain cleanliness and/or sterility of molded portions 4 or to at least reduce the contamination following the molding process as much as possible . This permits to facilitate the operation of the steri li zation process .

Such a solution is of particular advantage when sterili zation apparatus 9 relies on sterili zation by means of a sterili zing irradiation . This allows to operate at lower energies , which means a longer li fetime and lower energy consumption .

Another advantage resides in that the sterili zation of molded portions 4 having a more complex geometry than a flat shape is rendered more ef ficient and/or easier .

Clearly, changes may be made to packaging machine 1 or the method as described herein without , however, departing from the scope of protection as defined in the accompanying claims .