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TEXT OF THE DESCRIPTION

The present invention relates to a treatment-by-immersion apparatus, configured for treating by immersion a web of packaging material wound off a reel, of the type comprising: a system for supplying the web of packaging material, for feeding the latter along a work path; and a tank, set along said work path, for containing a bath of a liquid, in which the web of packaging material that advances along the work path is immersed.

The tank generally comprises a bottom and an opening for introduction of the liquid into said tank.

An apparatus of the type referred to above, in particular for sterilization of the web of packaging material, is for example used in aseptic machines for producing containers filled with a liquid product and sealed, starting from the aforesaid web. In this case, the web of packaging material, wound off a reel and fed along the work path, traverses a so-called aseptic area of the machine where the sterilization apparatus is located, and in which it is moreover immersed in a tank containing a sterilizing liquid.

In this connection, the present applicant has noted that during operation of the above machines there are at times produced containers that present defects around the respective sealing bands, which are such as to jeopardize the hermeticity of the containers.

The present applicant has found that this occurs even when the welding means of the machine function properly.

The present applicant has hence hypothesized that the origin of such defective containers is to be sought in the web of packaging material, in particular in more or less evident structural defects present in the web.

However, the present applicant has been able to note that the problem mentioned above of defective containers arises even when the reel off which the web is wound has previously been found to be intact.

Surprisingly, the present applicant has hence understood that the structural defects of the web of packaging material, which prevent proper welding thereof and jeopardize the hermeticity of the final containers, are not infrequently generated within the sterilization apparatus of the machine.

In particular, the present applicant has noted that, whenever there is a machine stoppage and the tank containing the bath of sterilizing liquid is emptied out, subsequent filling of the tank may cause damage to the web on account of the pressure at which the liquid is introduced into the tank and impinges upon the web that is lying in the tank.

The above pressure is in effect set at relatively high values in order to guarantee rapid filling of the tank. It is evident that lower pressures could reduce the risk of damage to the web, but at the same time would prolong the duration of the filling operation and machine stoppage, with consequent reduction in the throughput of the machine.

The present applicant has instead understood that it is possible to overcome the drawback of any damage to the web and the technical problem deriving therefrom of production of non-hermetically closed containers, without reducing the throughput of the machine, by protecting the web of packaging material from the flow of sterilizing liquid that is introduced into the tank during the filling step.

In the present description, as likewise in the claims annexed thereto, some terms and expressions are to be considered, except where otherwise explicitly indicated, as having the meaning given in the ensuing definitions.

By the term “treatment by immersion” of an object is meant the application of at least one method or process whereby the object is immersed for a certain more or less prolonged period of time in a bath of a liquid having specific properties, which enable a particular effect to be achieved on the aforesaid object. With particular reference to a web of packaging material, the treatments by immersion include, but are not limited to, sterilization or decontamination, cleaning, and dyeing.

In an apparatus or unit for processing an object that advances in a direction of feed along a work path, a first position is said to be “upstream” of a second position when the first position precedes the second position with reference to the direction of feed of the object; vice versa, the second position is said to be “downstream” of the first position in so far as it follows the first position once again with reference to the direction of feed of the object. According to a first aspect, the present invention regards a treatment- by-immersion apparatus configured for treating by immersion a web of packaging material wound off a reel. Preferably, the treatment-by-immersion apparatus comprises a system for supply of said web of packaging material, in particular for feeding said web of packaging material along a work path. Preferably, the treatment-by-immersion apparatus comprises a tank, set along said work path, in particular for containing a bath of a liquid. Preferably, said web of packaging material that advances along said work path is immersed in said liquid in said tank. Preferably, said tank comprises a bottom. Preferably, said tank comprises an opening, in particular configured for introducing said liquid into said tank. Preferably, the treatment-by- immersion apparatus comprises a screen set inside said tank. Preferably, the screen is located between said opening and said work path, in particular to protect the web of packaging material from a direct flow of said liquid that is introduced into said tank through said opening.

Thanks to the aforesaid characteristics, the treatment-by-immersion apparatus described herein is able to prevent possible damage to the web of packaging material when the liquid is introduced into the tank for filling the latter.

According to a second aspect, the present invention regards a machine for producing containers filled with a liquid product and sealed, starting from a web of packaging material wound off a reel. Preferably, the machine comprises a treatment-by-immersion apparatus according to the aforesaid first aspect of the invention. Preferably, the machine comprises a drying apparatus, in particular for drying said web of packaging material. Preferably, the drying apparatus is set downstream of said treatment-by- immersion apparatus. Preferably, the machine comprises a forming and filling unit, in particular for producing said containers filled with a liquid product and sealed. Preferably, the forming unit is set downstream of said drying apparatus.

According to a third aspect, the present invention regards a method for treating by immersion a web of packaging material wound off a reel. Preferably, the method comprises the step of feeding said web of packaging material along a work path. Preferably, the method comprises the step of providing a tank containing a bath of a liquid. Preferably, the method comprises the step of immersing said web of packaging material that advances along said work path in said tank. Preferably, the step of providing said tank containing a bath of a liquid includes introducing said liquid into said tank through an opening of said tank. Preferably, the step of providing said tank containing a bath of a liquid includes intercepting via a screen a flow of said liquid introduced through said opening and directed against said web.

Thanks to the aforesaid characteristics, the machine described herein is able to prevent any possible damage to the web of packaging material when the liquid is introduced into the tank for filling the latter, and thus to guarantee production of perfectly sealed containers, in particular without reducing the production volume.

According to one or more of the aforesaid aspects, the present invention may comprise one or more of the characteristics listed below.

According to one or more embodiments, the treatment-by-immersion apparatus of the present invention is a sterilization apparatus for sterilizing a web of packaging material wound off a reel. In other words, according to one or more embodiments said treatment by immersion is a sterilization.

According to one or more embodiments, said liquid is of the sterilizing type.

According to one or more embodiments, the treatment-by-immersion apparatus comprises a pump unit, in particular for supplying said liquid into said tank through said opening.

According to one or more embodiments, said opening is provided on the bottom of said tank.

According to one or more embodiments, said feed system comprises a deviator roller that is rotatable about an axis of rotation, preferably located inside said tank. According to one or more embodiments, said work path develops along an outer surface of said deviator roller. Preferably, said screen is set between said bottom of said tank and said deviator roller.

Thanks to the aforesaid characteristics, the screen is able to protect the web of packaging material in an effective way.

According to one or more embodiments, said screen has a substantially planar conformation. According to one or more embodiments, said screen is parallel to at least one between the axis of rotation of said deviator roller and the bottom of said tank.

According to one or more embodiments, said screen is at a first distance from the bottom of said tank. According to one or more embodiments, said screen is at a second distance from said deviator roller.

According to one or more embodiments, said first distance is shorter than said second distance.

Thanks to the aforesaid characteristics, the screen is able to protect the web of packaging material in an effective way, intercepting the flow of the liquid and deviating the flow thereof already at the opening, at a certain safety distance from the web of packaging material.

According to one or more embodiments, said opening has a reference axis Z. According to one or more embodiments, said screen is configured for separating said opening with respect to said deviator roller so as to intercept any flow that traverses said opening that has a direction with an inclination with respect to said reference axis Z of less than or equal to 45°.

Thanks to the aforesaid characteristic, the screen is able to protect the web of packaging material in an effective way.

According to one or more embodiments, said screen is set between said opening and said web.

It is pointed out that some steps of the method described above may be independent of the order of execution referred to, except where there is expressly indicated as necessary a sequentiality or simultaneity between two or more steps. Moreover, some steps may be optional. Moreover, some steps may be carried out in a repetitive way, or else may be carried out in series or in parallel with other steps of the method.

Further characteristics and advantages of the present invention will emerge clearly from the ensuing description with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

Figure 1 is a schematic illustration of an example of the treatment-by-immersion apparatus described herein;

Figure 2 illustrates a detail of the apparatus of Figure 1;

Figure 3 is a cross-sectional view according to the plane III-III of Figure 2; and Figure 4 is a schematic illustration of a machine for producing containers filled with a liquid and sealed, starting from a web of packaging material wound off a reel.

In the ensuing description, various specific details are illustrated aimed at enabling an in-depth understanding of the embodiments. The embodiments may be obtained without one or more of the specific details, or with other methods, components, or materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that various aspects of the embodiment will not be obscured.

The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments.

With reference to Figure 1, a treatment-by-immersion apparatus, in particular a sterilization apparatus, is designated as a whole by the reference number 10. The sterilization apparatus 10 comprises a system for supply of a web of packaging material (designated by the reference number 100) for feeding said web 100 along a work path KI.

As will be seen in what follows, the aforesaid feed system may form a portion of a wider feed system provided in a machine for producing containers, where the web 100 of packaging material wound off a reel is fed along a work path K (comprising the work path KI) and, along said work path K, undergoes treatments and processes until containers filled with a liquid product and sealed are obtained.

The sterilization apparatus 10 further comprises a tank 20, which is configured for containing a bath 20’ of a sterilizing liquid and, at the same time, is designed to be traversed by the work path KI of the web 100. The sterilizing liquid may for example be a solution of peroxide in water.

According to one or more preferred embodiments, like the one illustrated, the tank comprises a ???generic U shape [?portion having a generic U shape]. According to one or more preferred embodiments, like the one illustrated, the tank 20 comprises a first vertical branch 21, or upstream branch (with reference to the direction of advance of the web 100 along the work path KI), a second vertical branch 22, or downstream branch, and a chamber 23, which sets the two branches 21, 22 in communication.

According to one or more preferred embodiments, like the one illustrated, the branches 21, 22 and the chamber 23 are defined by respective distinct containers 21’, 22’, and 23’, connected together. According to one or more preferred embodiments, like the one illustrated, the branches 21 and 22 each comprise a container having a generic flattened conformation, which encloses within it a restricted passage. On the other hand, the chamber 23 is defined by a generically cylindrical container, the geometrical axis of which is oriented horizontally.

In the chamber 23, the web 100 undergoes a reversal of the motion, from a top-down direction of motion that it follows in the first branch 21, to a bottom-up direction of motion that it follows in the second branch 22.

Located inside the chamber 23 is a deviator roller 24 that is rotatable about a substantially horizontal axis of rotation I. The work path KI develops along an outer surface 24 A of the deviator roller 24 so that the web 100 that comes from the first branch 21 enters the chamber 23, runs over the deviator roller 24, and is thus directed towards the second branch 22.

On the bottom 23B of the tank 20, which in effect corresponds to the bottom of the chamber 23, an opening 23 C is provided, through which the sterilizing liquid, fed by a supply duct 32, is introduced into the tank 20 itself. Preferably, the sterilization apparatus 10 comprises a pump unit 33 for supplying the liquid to the tank 20.

The sterilization apparatus 10 comprises a screen 26, located within the tank 20, to protect the web 100, i.e., the portion thereof that extends in the tank 20 itself, from a direct flow F of the sterilizing liquid that is introduced into the tank 20 through the opening 23 C.

With reference to the embodiment illustrated in Figure 2, the screen 26 is in particular located within the chamber 23, between the opening 23 C and the deviator roller 24, setting itself between the latter.

The screen 26 has, in this embodiment, a substantially planar conformation and is parallel to the axis of rotation I of the deviator roller 24 and to the bottom 23B. Moreover, the screen 26 is positioned vertically at a distance DI from the bottom 23B that is less than a distance D2 between the screen 26 and the deviator roller 24 (see Figure 2).

According to one or more preferred embodiments, like the one illustrated, the screen 26 has a limited extension, less than the area of the portion of the web 100 directly facing the bottom 23B of the tank 20 and the opening 23 C provided thereon. According to one or more embodiments, like the one illustrated, the screen 26 is configured for separating the opening 23 C from the deviator roller 24 so as to intercept any low through the opening 23 C having a direction that is parallel to the reference axis Z of the opening itself or, in any case, inclined with respect to the axis Z up to an angle of 45°.

In this way, the screen 26 is able to intercept even possible flows of sterilizing liquid that have a direction incident to the web 100 according to angles other than 90°.

In view of the foregoing, it will be understood that the screen 26 prevents any possible damage to the web 100 of packaging material caused by the flow of sterilizing liquid introduced into the tank 20. Consequently, the solution described herein prevents the technical problem mentioned at the start, regarding the production of containers that lack a perfect hermeticity.

Figure 4 is a schematic illustration of a machine for producing containers filled with a liquid product and sealed, which includes the sterilization apparatus 10 illustrated above. With reference to Figure 4, in a way in itself known, the machine illustrated comprises a supply system for feeding the web 100 along a work path K (that comprises the work path KI within the sterilization apparatus 10) and moreover comprises, arranged in succession along the work path K, the sterilization apparatus 10, a drying apparatus 40 for drying the web 100 coming from the sterilization apparatus 10, and a forming and filling unit 50 for producing with the web 100 the containers filled with the liquid product and sealed. As mentioned at the outset, during a machine stoppage, the tank 20 of the sterilization apparatus 10 is completely emptied out and filled again only immediately prior to start of operation of the machine. Thanks to the screen 26 provided in the sterilization apparatus 10 described herein, the web of packaging material is protected from any possible damage during the step of filling of the tank. This guarantees that the web of packaging material will remain intact and unaltered so as to prevent production of defective containers.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary, even significantly, with respect to what has been illustrated herein purely by way of non-limiting example, without thereby departing from the scope of the invention, as defined by the annexed claims.