EP4613661A1

EP4613661A1 - Sterilizing agent removal assembly for a packaging apparatus configured to produce sealed packages containing a pourable product

Info

Publication number: EP4613661A1
Application number: EP25156987.7A
Authority: EP
Inventors: Emanuele Antonino MEO; Daniele Apparuti
Original assignee: Tetra Laval Holdings and Finance SA
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 2024-03-04
Filing date: 2025-02-11
Publication date: 2025-09-10
Also published as: WO2025185930A1; WO2025185930A8

Abstract

There is described a sterilizing agent removal assembly (12) for a sterilizing unit (7) of a packaging apparatus (1) configured to produce packages starting from a web (4) of packaging material provided with a longitudinal sequence of closure structures (5) pre-applied thereon, the assembly (12) comprises: a first nozzle device (14) and a second nozzle device (15) arranged facing one another, defining between one another a treatment zone (Z) for the web (4) to advance therethrough and configured to blow gas towards a respective side (4a, 4b) of the web (4); the first nozzle device (14) comprises a first nozzle wall (16) provided with openings (17) for the flow of gas, the second nozzle device (15) comprises a second nozzle wall (18) provided with openings (17, 21, 22) for the flow of gas; the second nozzle device (15) is provided with a slot (19) obtained on the second nozzle wall (18) and adapted to be repeatedly engaged by said sequence of closure structures (5), so as to allow the transit of the web (4) with its closure structures (5) through said treatment zone (Z).

Description

TECHNICAL FIELD

The present invention relates to a sterilizing agent removal assembly for a sterilization unit of a packaging apparatus configured for the production of sealed packages containing a pourable product, preferably a pourable food product.

BACKGROUND ART

As it is generally known, many 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 pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated web of packaging material.
The packaging material has a multilayer structure comprising a base layer, e.g. made 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, 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 apparatuses, which form and fill the packages starting from a multilayer web of packaging material.
In particular, a continuous tube is formed from the web of packaging material which is initially wound in a reel and fed through a plurality of unwinding rollers. The web of packaging material is typically sterilized in the packaging apparatus, e.g. by applying a chemical sterilizing agent, such as hydrogen peroxide solution, which, once sterilization is completed, is removed from the surfaces of the packaging material, e.g. evaporated by heating. The web so sterilized is then maintained in a closed, sterile environment, and, while advanced by the aforementioned unwinding rollers, is folded to form the tube by means of a known web folding unit and then sealed longitudinally.
In order to perform the package forming operations, the tube is continuously fed along a first direction, normally a straight vertical direction, is filled with the sterilized food product from above and is formed, sealed and subsequently cut along equally spaced transversal cross-sections extending along a second direction, normally a direction orthogonal to the first direction.
In detail, a typical packaging apparatus comprises a plurality of forming, sealing and cutting assemblies, each one advanced along an operative path parallel to the first direction. During such advancement, the forming, sealing and cutting assemblies start interacting with the tube at preset positions along the operative path and follow the tube advancing along the first direction so as to shape, to transversally seal and to cut the tube so as to obtain single pillow packs.
In greater detail, the known packaging apparatuses comprise a forming and sealing unit configured to form the tube, so as to imprint an external shape to it, corresponding to the desired shape of the package, and to seal the tube at equally spaced cross-sections orthogonal to the tube advancement direction.
Generally, a packaging apparatus of the above type comprises a pair of alternately movable forming and sealing jaws which are controllable with a reciprocating movement in the first direction and in a third direction orthogonal to the first direction and second direction to interact with the tube at successive portions thereof.
So-called pillow packs are obtained thereby, which have a longitudinal sealing band, a top transversal sealing band and a bottom transversal sealing band. The pillow packs are then cut at the cross-sections to be separated from one another and directed to a folding unit of the packaging machine for the final folding thereof.
The finished packages are thereby obtained.
As said, the web of packaging material must be sterilized before being folded into the tube.
Accordingly, a typical packaging apparatus comprises a sterilization unit arranged upstream of the web folding unit and configured to apply a chemical sterilizing agent, usually containing hydrogen peroxide.
After the application and the sterilization, the sterilizing agent must be removed from the web.
To this end, the sterilization unit typically comprises a pair of squeezing rollers, and in particular a roller and a counter-roller, arranged in rotational abutment against one another and configured to receive the advancing web therebetween.
By advancing the web in between the squeezing rollers, the sterilizing agent is substantially squeezed off the web itself.
In some cases, possible residues of sterilizing agent are fully dried out and/or removed by a blowing device arranged downstream of the squeezing rollers and configured to blow a jet of gas (usually sterilized air) towards the web.
In light of the above, the sterilization unit comprises a sterilization agent removal assembly which includes the squeezing rollers and the blowing device.
The use of webs of packaging material provided with a longitudinal sequence of closure structures pre-applied thereon is increasingly widespread.
In particular, each one of the aforementioned closure structures is defined by a neck of a closure (made of plastic material) adapted to receive a cap (made of plastic material as well), which neck is pre-applied by a molding process on the web of packaging material prior to the formation of the tube, according to a manner known and not described in detail.
It is evident that if a web provided with pre-applied closure structures is used the removal of the sterilizing agent is more challenging.
To this end, the sterilization agent removal assemblies for the sterilization units of the packaging apparatuses operating with such type of web have been equipped with a pair of nozzle devices, in particular a first nozzle device and a second nozzle device arranged at opposite sides of the advancing web, facing one another, and configured to blow air towards a respective side of the web. The nozzle devices may substitute or be provided in addition to the squeezing rollers. According to a particular embodiment, the squeezing rollers have a profile shaped so to define a groove configured to allow the passage of the pre-applied closure structures; in such embodiment, the nozzle devices may be located within said grooves of the squeezing rollers.
In particular, the first nozzle device is configured to direct a flow of air towards an inner side of the web adapted to define the inner wall of the packages, whereas the second nozzle device is configured to direct a flow of air towards an outer side of the web adapted to define the outer wall of the packages.
More specifically, each nozzle device has a respective blowing wall, arranged facing the blowing wall of the other nozzle device, with the interposition in use of the advancing web, and provided with a series of shaped ports or openings through which the flow of air is supplied towards the respective side of the web.
In order to allow a free passage of the closure structures, which normally protrude from the aforementioned outer side of the web, the second nozzle device is arranged so that a distance of its blowing wall from the outer side of the web is greater than a distance of the blowing wall of the first nozzle device from the inner side of the web.
Although the sterilization agent removal assemblies of the type mentioned above are structurally and functionally valid, the Applicant has observed that they are still open to further improvements, in particular as per their efficiency in terms of energy consumption and the reduction of corrosion in the components of the packaging apparatus which are located around and downstream of the sterilizing unit. In this last regard, the Applicant has observed that the closure structures pre-applied on the web may retain more sterilizing agent residues than the web, which residues may fall and deposit on other components of the packaging apparatus, thereby accelerating the corrosion thereof.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide a sterilizing agent removal assembly for a sterilizing unit of a packaging apparatus configured to produce sealed packages containing a pourable product, which is designed to meet at least one of the above-mentioned needs in a straightforward and low-cost manner.
This object is achieved by a sterilizing agent removal assembly as claimed in the appended independent claim 1. Preferred embodiments of the present invention are laid down in the appended 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 drawings, in which:

Figure 1 is a schematic perspective view, with parts removed for clarity, of a packaging apparatus including a sterilization unit equipped with a sterilizing agent removal assembly according to the present invention;
Figure 2 is a larger-scale lateral view, with parts removed for clarity, of part of the sterilizing agent removal assembly according to the invention;
Figure 3 is a larger-scale top view of the sterilizing agent removal assembly of Figure 2;
Figure 4 is an exploded perspective view, with parts removed for clarity, of the sterilizing agent removal assembly according to the invention; and
Figures 5 and 6 are larger-scale perspective views of a nozzle device of the sterilizing agent removal assembly according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to Figure 1, number 1 indicates as a whole a non-limiting example of a packaging apparatus configured for producing a plurality of sealed packages 2 containing a pourable product, preferably a pourable food product such as pasteurized or UHT milk, water, fruit juice, wine, peas, beans, etc.
In detail, packaging apparatus 1 is configured to form, seal and fold packages 2 starting from a web 4 of packaging material, which is initially wound in a reel 50, and then folded into a tube 3 of packaging material, as explained below.
Preferably, the packaging material has a multilayer structure (not shown), and comprises a layer of fibrous material, e.g. paper, covered on both sides with respective layers of heat-seal plastic material, e.g. polyethylene.
In the case of aseptic packages 2 for long-storage products, such as UHT milk, the packaging material also comprises a layer of gas-and-light barrier material, e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material, the latter forming the inner face of package 2 eventually contacting the pourable product.
As said, the packaging material is initially provided in the form of a web 4.
The present disclosure refers to a packaging apparatus 1 which uses a web 4 provided with a longitudinal sequence of closure structures 5 pre-applied thereon, as shown in Figure 1.
In particular, each one of the aforementioned closure structures 5 is defined by a closure (preferably made of plastic material) adapted to receive a cap (preferably made of plastic material as well). The closure is pre-applied by a molding process on web 4 prior to the formation of tube 3, according to a manner known and not described in detail.
More in particular, as shown in Figures 2 and 3, each closure structure 5 has a neck 5a and a base 5b embedded in the packaging material in a known manner.
In detail, neck 5a protrudes (orthogonally) from a first side 4a of web 4, which first side 4a is an outer side of web 4 destined to define the outer wall of packages 2. Base 5b protrudes (slightly) from first side 4a and also (slightly) from a second side 4b of web 4, which second side 4b is opposite to first side 4a and is an inner side of web 4 destined to define the inner wall of packages 2, i.e. the wall which contacts, in use, the pourable product.
As schematically shown in Figure 1, the packaging apparatus 1 comprises conveying means configured to advance the web 4 along an advancement path.
The packaging apparatus 1 comprises a tube folding device 6 for progressively folding the advancing web 4 into a tube 3 of packaging material, in a manner known and not described in detail.
The packaging apparatus 1 comprises a sealing element 40 for providing tube 3 with a longitudinal seal, in a manner known and not described in detail.
The packaging apparatus 1 comprises a sterilization unit 7 configured for applying a sterilizing agent, for example containing hydrogen peroxide, on web 4 prior to its folding into tube 3.
The packaging apparatus 1 comprises a forming and sealing unit 8 for forming tube 3 by imparting a predetermined external shape, corresponding to a precursor of the shape of package 2, to successive longitudinal portions of tube 3, and for sealing tube 3 at equally spaced cross-sections.
The packaging apparatus 1 comprises an isolation chamber 10 internally defining an environment containing a controlled atmosphere, in particular sterile and/or aseptic gas, preferably sterile and/or aseptic air, and housing the forming and sealing unit 8 and the tube folding device 6.
The packaging apparatus 1 comprises a filling system 11 to fill tube 3 with the pourable product.
Preferably, forming and sealing unit 8 has an axis X along which tube 3 is fed, in use.
Axis X is parallel to a straight direction, which preferably is a straight vertical direction.
Hence, in use, tube 3 is fed along axis X, downwards, and while being filled from above is formed and sealed by forming and sealing unit 8, according to a manner known and not described in detail.
More specifically, tube 3 is drawn (downwards) along axis X by forming and sealing unit 8 in a known manner.
In this way, a plurality of pillow packs 2a are obtained.
Packaging apparatus 1 may further comprise a folding unit (known per se and not shown) for folding the pillow packs 2a, thereby obtaining packages 2, according to a manner known and not described in detail.
Hence, packaging apparatus 1 is configured to form and seal a plurality of pillow packs 2a containing the pourable product starting from web 4 and tube 3 and then to fold the pillow packs 2a for obtaining the aforementioned formed, sealed and folded packages 2 containing the pourable product.
In order to sterilize also the closure structures 5, web 4 is conveniently provided with closure structures 5 at a position upstream of sterilization unit 7, with respect to the advancement path.
Sterilization unit 7 includes a sterilizing agent removal assembly 12 which is configured to remove the sterilizing agent from web 4 and from closure structures 5.
As shown in Figures 2 and 3, assembly 12 comprises or defines a longitudinal axis A.
Assembly 12 comprises a blower 13 (only schematically shown) for supplying a flow of gas, and preferably a flow of sterile air withdrawn from isolation chamber 10.
Assembly 12 comprises a first nozzle device 14 and a second nozzle device 15 arranged facing one another, defining between one another a treatment zone Z for web 4 to advance therethrough and configured to receive the flow of gas and to blow gas towards a respective side 4a, 4b of web 4.
In detail, first nozzle device 14 and second nozzle device 15 are arranged on opposite lateral sides of axis A and face one another along a transversal direction orthogonal to axis A.
In greater detail, axis A extends through treatment zone Z.
In use, web 4 is configured to be advanced along axis A, when transiting within sterilization unit 7, as schematized in Figure 1, and as shown in Figures 2, 3.
First nozzle device 14 is configured to direct the flow of gas towards second side 4b of web 4 and comprises a first nozzle wall 16 provided with shaped ports or openings 17 through which first nozzle device 14 is configured to supply the flow of gas.
Similarly, second nozzle device 15 is configured to direct the flow of gas towards first side 4a of web 4 and comprises a second nozzle wall 18 provided with shaped ports or openings 17 through which second nozzle device 15 is configured to supply the flow of gas.
To this end, both first nozzle device 14 and second nozzle device 15 are fluidly connected to blower 13 through respective ducts 13a and 13b, as schematically shown in Figures 2 and 3.
First nozzle wall 16 and second nozzle wall 18 face one another along said transversal direction orthogonal to axis A.
In light of the above, treatment zone Z is defined as the region of space within sterilization unit 7 comprised between, and laterally delimited by, first nozzle wall 16 and second nozzle wall 18.
In other words, first nozzle device 14 and second nozzle device 15 are arranged at opposite sides of axis A and face one another with the interposition of treatment zone Z and of axis A.
The openings 17 may be shaped as elongated slits and/or substantially circular holes. In particular, the second nozzle wall 18 may include a group of openings 17 shaped as elongated slits (elongated perpendicularly to axis A) and/or a group of openings 22 shaped as circular holes.
In one embodiment, openings 22 may be defined by a single elongated slot and/or a group of elongated and/or discontinued slots.
According to an aspect of the present disclosure, second nozzle device 15 is provided with a slot 19 obtained on second nozzle wall 18 and adapted to be repeatedly crossed (or engaged) by said sequence of closure structures 5, so as to allow the transit of web 4 with its closure structures 5 through treatment zone Z.
In other words, in use each closure structure 5 engages without interference slot 19.
In particular, slot 19 extends in the axial direction, i.e. parallel to axis A, and is open in the axial direction thereby defining a through passage for the closure structures 5 along the axial direction.
More in particular, slot 19 defines a recess on second nozzle wall 18, which recess is (posteriorly) delimited by a back wall 18a and (laterally) by a pair of lateral walls 20 facing one another, and is open (anteriorly) towards first nozzle wall 16.
In detail, back wall 18a is parallel to the axial direction and lateral walls 20 are substantially orthogonal to back wall 18a and face one another along a direction orthogonal to axis A and to said transversal direction.
In greater detail, and according to this non-limiting and preferred embodiment, slot 19 is defined by a substantially rectangular-shaped recess, namely a recess with a C-shaped cross section.
In light of the above, it is possible to identify two wall portions on second nozzle wall 18: a first wall portion, defined by back wall 18a (or which defines back wall 18a), and a second wall portion 18b distinct from first wall portion 18a.
Basically, first wall portion 18a defines the back wall of slot 19 and second wall portion 18b defines the rest of second nozzle wall 18 which is outside of slot 19 - and which laterally surrounds slot 19, as best visible in Figure 6.
According to a further aspect of the invention first nozzle wall 16 is arranged at a first distance D1, measured along said transversal direction, from axis A, so as to be arranged, in use, at first distance D1 from web 4 advancing through the treatment zone Z.
Furthermore, first wall portion 18a (i.e. the back wall of slot 19) is arranged at a second distance D2, measured along said transversal direction, from axis A, so as to be arranged in use at second distance D2 from web 4 advancing through the treatment zone Z, second distance D2 being advantageously greater than first distance D1 so as to allow an engagement of slot 19 by the sequence of closure structures 5 along the axial direction.
Moreover, second wall portion 18b is arranged at a third distance, measured along said transversal direction, from axis A, so as to be arranged, in use, at the third distance from web 4 advancing through the treatment zone Z, the third distance being smaller than second distance D2.
Preferably, third distance is equal to first distance D1. I.e., second wall portion 18b is arranged at said first distance D1 from axis A.
This peculiar configuration is best visible in Figure 3.
In light of the above, as web 4 advances along the advancement path carrying the closure structures 5 with itself, it enters sterilizing unit 7 and hence treatment zone Z.
The particular conformation of second nozzle device 15 according to the present invention, whereby its second nozzle wall 18 is provided with slot 19 having the aforementioned shape, allows the passage of closure structures 5 through slot 19 without interference.
Furthermore, the fact that the rest of second nozzle wall 18, i.e. second wall portion 18b, is arranged at first distance D1 (shorter than second distance D2 and equal to the distance from web 4 at which first nozzle wall 16 is arranged) determines a significant improvement of the efficacy and effectiveness of sterilizing agent removal, with respect to the known solutions whereby the whole second nozzle wall is arranged at the second distance.
In addition, for the same reasons, there is no need for an increase in power for the supply of gas (sterile air) to second nozzle device 15, thereby leading to energy (and therefore costs) savings.
Second wall portion 18b is provided with a respective plurality of said shaped ports or openings 17, which are configured to face web 4 for directing the flow of gas towards web 4. In particular, second wall portion 18b is provided with a group of openings 17 elongated transversally to the axis A and a group of openings 22 shaped as circular holes.
As said, web 4 is at first distance D1 from second wall portion 18b.
Conveniently, also first wall portion 18a is provided with a respective plurality of said shaped ports or openings 17, which are configured to face closure structures 5 for directing the flow of gas towards the respective closure structures 5 engaging slot 19 in use. In particular, second wall portion 18b is provided with openings 17 elongated transversally to the axis A.
Advantageously, also each lateral wall 20 is provided with a further respective plurality of shaped ports or openings 21 arranged so as to repeatedly face towards the respective closure structures 5 engaging slot 19.
In particular, the shaped ports or openings 21 of each lateral wall 20 are expediently arranged so as to repeatedly face base portion 5b and/or a neck portion 5a of each closure structure 5 engaging slot 19.
More in particular, such shaped ports or openings 21 are arranged at an edge portion of the respective lateral wall 20 joining lateral wall 20 and second wall portion 18b. Even more in particular, the edge portion is (slightly) inclined with respect to the rest of lateral wall 20. In such a way, an axis of openings 21 is inclined with respect to axis A.
The Applicant has observed that the presence of further openings 21 on lateral walls 20, and in particular their peculiar arrangement, increases the removal of sterilizing agent from areas of the closure structures 5 in which the sterilizing agent is most retained.
For example, an embodiment whereby openings 21 are directed so as to repeatedly face the base portion 5b of each closure structure 5 engaging slot 19 has been found to be particularly advantageous. In fact, base portion 5b is often a place which retains sterilizing agent.
Thanks to the improved removal of sterilizing agent, the Applicant has observed a drastic decrease of corrosion in other parts and components of packaging apparatus 1, which ultimately lead to an increased lifespan of the same.
Advantageously, at least one of the shaped ports or openings of first wall portion 18a is configured for directing the flow of gas inside the neck portion 5a of each closure structure 5 engaging slot 19.
More specifically, in one embodiment first wall portion 18a may be equipped with further openings 22 specifically configured for directing the flow of gas inside neck portions 5a.
This configuration is particularly, but not exclusively, advantageous for closure structures 5 with relatively complicated inner design.
In one or more embodiments, first wall portion 18a may be equipped with further openings 22 specifically configured for directing the flow of gas inside neck portions 5a.
In this way, the removal of sterilizing agent is further improved.
As visible in Figures 2 to 6, second nozzle device 15 comprises a nozzle frame 23 and a nozzle member 24 coupled with nozzle frame 23.
In detail, nozzle member 24 carries second nozzle wall 18 so that slot 19 is defined on nozzle member 24.
Advantageously, nozzle member 24 is removably couplable with nozzle frame 23.
In particular, according to an aspect of the invention, assembly 12 comprises a series of nozzle members 24, whereby each nozzle member 24 includes a slot 19 which is different for shape and/or size from the slots 19 of the other nozzle members 24 of said series of nozzle members 24.
Hence, according to such aspect of the invention, nozzle members 24 are interchangeable with one another.
In particular, nozzle members 24 are interchangeable depending on the shape of the closure structures 5 pre-applied on the web 4 to be treated.
In this way, the flexibility of sterilizing agent removal assembly 12 is highly increased. At the same time, as second nozzle device 15 can be selected based on the closure structure 5, i.e. it is "tailored" on the type of closure structure 5 to treat, the effectiveness and efficacy of the sterilizing agent removal is largely improved.
In light of the above, assembly 12 according to the present invention allows to define a kit for the removal of a sterilizing agent from a web 4 of packaging material which is provided with a longitudinal sequence of closure structures 5 pre-applied thereon, the kit comprising:

the sterilizing agent removal assembly 12; and
a plurality of nozzle members 24, whereby each nozzle member 24 includes a slot 19 which is different for shape and/or size from the slots 19 of the other nozzle members 24, said nozzle members 24 being interchangeable with one another;

The advantages of assembly 12 according to the present invention will be clear from the foregoing description.
In particular, the presence of second nozzle device 15 provided with a slot 19 as described above for the passage of the closure structures 5 pre-applied on web 4 determines a significant improvement of the efficacy and effectiveness in removing the sterilizing agent, with respect to the known solutions whereby the whole second nozzle wall is arranged at a larger distance with respect to the first nozzle wall.
In addition, for the same reasons, there is no need for an increase in power for the supply of gas (sterile air) to second nozzle device 15, thereby leading to energy (and therefore costs) savings.
Furthermore, the presence of dedicated openings 21, 22 for the closure structures 5 in the slot 19 increases the efficacy of removal of the sterilizing agent from areas of the closure structures 5 in which the sterilizing agent is mostly retained. Ultimately, this results in a drastic decrease of corrosion in other parts and components of packaging apparatus 1, which ultimately lead to an increased lifespan of the same.
Clearly, changes may be made to assembly 12 as described herein without, however, departing from the scope of protection as defined in the accompanying claims.

Claims

Sterilizing agent removal assembly (12) for a sterilizing unit (7) of a packaging apparatus (1) configured to produce sealed packages containing a pourable product starting from a web (4) of packaging material provided with a longitudinal sequence of closure structures (5) pre-applied thereon, the assembly (12) comprising:
- a blower (13) for supplying a flow of gas;

- a first nozzle device (14) and a second nozzle device (15) arranged facing one another, defining between one another a treatment zone (Z) for the web (4) to advance therethrough, and configured to receive the flow of gas and to blow the gas towards a respective side (4a, 4b) of the web (4);
wherein the first nozzle device (14) is configured to direct the flow of gas towards a first side (4b) of the web (4) destined to define an inner wall of the packages (2), and comprises a first nozzle wall (16) provided with openings (17) through which the first nozzle device (14) is configured to supply the flow of gas,

wherein the second nozzle device (15) is configured to direct the flow of gas towards a second side (4a) of the web (4) destined to define an outer wall of the packages (2), and comprises a second nozzle wall (18) provided with openings (17, 21, 22) through which the second nozzle device (15) is configured to supply the flow of gas;

and wherein the second nozzle device (15) is provided with a slot (19) obtained on the second nozzle wall (18) and adapted to be repeatedly crossed by said sequence of closure structures (5), so as to allow the transit of the web (4) with its closure structures (5) through said treatment zone (Z).
Sterilizing agent removal assembly as claimed in claim 1, and defining a longitudinal axis (A) extending through the treatment zone (Z) and along which the web (4) is configured to be advanced, in use;
wherein the first nozzle device (14) and the second nozzle device (15) are arranged at opposite sides of the longitudinal axis (A);

wherein the first nozzle wall (16) and the second nozzle wall (18) face one another along a transversal direction orthogonal to said longitudinal axis (A);

and wherein the slot (19) is elongated along an axial direction parallel to said longitudinal axis (A) thereby defining a through passage along the axial direction.
Sterilizing agent removal assembly as claimed in claim 2, wherein the first nozzle wall (16) is arranged at a first distance (D1), measured along said transversal direction, from said longitudinal axis (A), so as to be arranged, in use, at said first distance (D1) from the web (4);
the second nozzle wall (18) having:
- a first wall portion (18a) which defines a back wall of said slot (19) and is arranged at a second distance (D2), measured along said transversal direction, from said longitudinal axis (A), so as to be arranged, in use, at said second distance (D2) from the web (4), the second distance (D2) being greater than the first distance (D1) so as to allow a crossing of the slot (19) by the sequence of closure structures (5) along the axial direction; and

- a second wall portion (18b) distinct from said first wall portion (18a) and arranged at a third distance, measured along said transversal direction, from said longitudinal axis, so as to be arranged, in use, at said third distance from the web (4), the third distance being smaller than the second distance (D2).
Sterilizing agent removal assembly as claimed in claim 3, wherein said third distance is equal to said first distance (D1).
Sterilizing agent removal assembly as claimed in claim 3 or 4, wherein the second wall portion (18b) is provided with a respective plurality of said openings (17) configured to face said web (4) for directing the flow of gas towards said web (4);
and wherein the first wall portion (18a) is provided with a respective plurality of said openings (22) configured to face the closure structures (5) for directing the flow of gas towards the respective closure structures (5) crossing said slot (19).
Sterilizing agent removal assembly as claimed in claim 5, wherein the second nozzle wall (18) includes a pair of lateral walls (20) extending transversally to said first wall portion (18a);
wherein the slot (19) is delimited by said back wall portion (18a) and by said pair of lateral walls (20) facing one another and is open towards the first nozzle wall (16);

and wherein each said lateral wall (20) is provided with at least one of said openings (21) arranged so as to repeatedly face, in use, towards the respective closure structures (5) crossing said slot (19).
Sterilizing agent removal assembly as claimed in claim 6, wherein the at least one of said openings (21) of each said lateral wall (20) are arranged so as to repeatedly face, in use, a base portion (5b) and/or a neck portion (5a) of each closure structure (5) crossing said slot (19).
Sterilizing agent removal assembly as claimed in claim 6 or 7, wherein the at least one of said openings (21) of each said lateral wall (20) is arranged at an edge portion of the lateral wall (20) joining the lateral wall (20) and the second wall portion (18b).
Sterilizing agent removal assembly as claimed in any one of claims 5 to 8, wherein at least one of the openings (22) of the first wall portion (18a) is configured for directing the flow of gas inside a hollow neck portion (5a) of each closure structure (5) crossing said slot (19).
Sterilizing agent removal assembly as claimed in any one of the foregoing claims, wherein the slot (19) defines a recess on said second nozzle wall (18), the recess being delimited by a back wall (18a) and by a pair of lateral walls (20) facing one another, the recess being open towards the first nozzle wall (16).
Sterilizing agent removal assembly as claimed in any one of the foregoing claims, wherein the second nozzle device (15) comprises a nozzle frame (23) and a nozzle member (24) removably couplable with the nozzle frame (23), the nozzle member (24) carrying the second nozzle wall (18) so that said slot (19) is defined on the nozzle member (24).
Sterilizing agent removal assembly as claimed in claim 11, and comprising a series of said nozzle members (24), whereby each nozzle member (24) includes a slot (19) which is different for shape and/or size from the slots (19) of the other nozzle members (24) of said series of nozzle members (24);
wherein said nozzle members (24) are interchangeable with one another.
Sterilizing agent removal assembly as claimed in any of the foregoing claims, and defining a longitudinal axis (A) extending through the treatment zone (Z) and along which the web (4) is configured in use to be advanced, wherein at least some of said openings (17, 21, 22) are elongated orthogonally to the axial direction.
Kit for the removal of a sterilizing agent from a web (4) of packaging material which is provided with a longitudinal sequence of closure structures (5) pre-applied thereon, the kit comprising:
- a sterilizing agent removal assembly (12) as claimed in any one of the foregoing claims, wherein the second nozzle device (15) comprises a nozzle frame (23) and a nozzle member (24) removably couplable with nozzle frame (23), the nozzle member (24) carrying the second nozzle wall (18) so that said slot (19) is defined on the nozzle member (24);

- a plurality of nozzle members (24), whereby each nozzle member (24) includes a slot (19) which is different for shape and/or size from the slots (19) of the other nozzle members (24) of said plurality of nozzle members (24), said nozzle members (24) being interchangeable with one another;
wherein the kit is configured to be implemented in a sterilizing unit (7) of a packaging apparatus (1) for the production of sealed packages (2) containing a pourable product.
Packaging apparatus (1) configured for producing sealed packages (2) containing a pourable product starting from a web (4) of packaging material provided with a longitudinal sequence of closure structures (5) pre-applied thereon, the apparatus comprising:
- conveying means configured to advance the web (4) along an advancement path;

- a sterilization unit (7) for applying a sterilizing agent on the web (4) and on the closure structures (5) and including a sterilizing agent removal assembly (12) as claimed in any one of the foregoing claims 1 to 14 and configured to remove the sterilizing agent from the web (4) and the closure structures (5);

- a tube folding device (6) for folding the web (4) into a tube (3);

- a sealing element (40) for longitudinally sealing the tube (3);

- a forming and sealing unit (8) for forming the tube (3) and transversally sealing the tube (3) at cross-sections thereof, thereby obtaining a plurality of packs (2a) from which the packages (2) are subsequently obtained.