The present invention concerns a packaging device for packaging articles into boxes and relative method, which are particularly suitable for packaging articles in accordance with a process in which it is provided to form the box around the article to be packaged, known in the art as "wraparound" process.

The content of the following Italian patent applications, filed by the same Applicant, is considered to be fully incorporated herein:

- Italian patent application no. 102021000032915 entitled "Packaging device for packaging articles into boxes and relative packaging method" filed on 29 December 2021;

- Italian patent application no. 102021000032933 entitled "Packaging device for packaging articles into boxes and relative packaging method" filed on 29 December 2021;

- Italian patent application no. 102022000011699 entitled "Packaging device for packaging articles into boxes" filed on 1 June 2022; and

- Italian patent application no. 102022000011687 entitled "Packaging unit for packaging articles into boxes and relative packaging method" filed on 1 June 2022.

The present invention finds a preferred, although not exclusive, application in the field of packaging into boxes articles with variable geometry and which are relatively delicate, such as for example bags of corn flakes, a sector to which reference may be made below without however losing generality.

In particular, in the relevant technical field, it is known to package articles into a box according to two distinct manners.

A first manner provides for a first step of forming a box, which is open at least at one end thereof, the subsequent insertion of the article to be packaged into the open box and, then, the closure of the open end.

A second manner instead provides that the box is formed by wrapping a blank, for example a shaped and creased cardboard, around a mandrel made of rigid material, for example made of metal, containing the article to be packaged. This manner provides that the blank is wrapped around the mandrel so as to form a box that is closed laterally but open at one end thereof, from which the mandrel is then extracted leaving the article inside the newly formed box. Also in this case, the open end can be conveniently closed, so that the package thus made can be sent to the final steps of packaging and shipment to the points of sale.

In this description as well as in the accompanying claims, certain terms and expressions are deemed to have, unless otherwise expressly indicated, the meaning expressed in the following definitions.

The term "article" means any product that can be packaged into boxes.

The articles can have a predetermined geometric shape or they can have a variable geometry.

Preferably, the articles are food and confectionery articles, in bulk or contained inside bags or other types of wrapping, such as for example cereal bags or coffee capsules or other infusion beverages, single chocolates (wrapped or not), candies, pouches containing solid, liquid or semisolid food products; in addition, articles of the ceramic industry, absorbent articles for hygienic use, articles of the tobacco industry, articles of the cosmetic industry, articles of the pharmaceutical industry, articles of the "personal & home care" industry.

By "packaging" one or more articles in a box, it is meant the fact of obtaining a box containing said one or more of said articles. Such packaging can be obtained by inserting one or more articles into an already formed box or, preferably, it can be obtained by forming a box around the one or more articles to be contained.

By "mandrel" it is meant a container capable, on the one hand, of accommodating and supporting one or more articles to be packaged and, on the other hand, of providing an effective abutment for folding the blank when wrapped around it.

For this purpose, it should be noted that accommodating and supporting such one or more articles do not in itself imply that they must be entirely accommodated inside the mandrel or completely supported by it, but it is sufficient for them to be accommodated in the moment in which the blank is wrapped around the mandrel.

Likewise, it should be noted that also the abutment of the blank does not imply in itself that the blank is abutted for its entire surface by the mandrel, but it is sufficient for it to be abutted to an extent such as to allow the correct folding necessary for the formation of the box.

In general terms, a first element "abuts" a second element when the first element touches the second element and is able to at least partially oppose a relative displacement of the first element against the second element.

By "blank" it is meant a shaped sheet of appropriate material and thickness which is suitable to be wrapped by folding around a mandrel to form a box.

Preferably, the blank is made of cardboard.

Preferably, the blank has a thickness of at least 0.2 mm, more preferably less than 4 mm. In a greatly preferred manner, the blank has a thickness comprised between 0.25 mm and 1.6 mm, more preferably between 0.3 mm and 1 mm, even more preferably between 0.4 and 0.8 mm.

By "box" it is meant any container suitable for containing a plurality of articles for the purpose of their packaging, which can be made starting from a blank by folding around a mandrel and subsequent fixing at its flaps.

A box is "partially closed" when the box has at least one closed contour section, more preferably it is closed laterally around the mandrel while the longitudinal ends are kept open.

By "flap" it is meant a region of the blank that allows fixing the blank to another region in such a way as to form an at least partially closed box, preferably around a mandrel.

Non-limiting examples of such a fixing are gluing, stapling and jointing by means of interlocking elements or elements with laces and hooks (Velcro®).

In particular, the fixing to form an at least partially closed box takes place by at least partially overlapping two flaps of the blank, an inner flap and an outer flap.

Specifically, it is intended to indicate with "outer flap" the flap that, overlapped on the inner flap, is located outside the at least partially closed box, whereas it is intended to indicate with "inner flap" the flap that, overlapped on the outer flap, is located between it and the inside of the at least partially closed box.

A "folding line" of a blank is a predetermined line about which two blank portions are provided to rotate relative to each other so as to fold the blank.

The folding line can be a virtual, albeit predefined line.

The folding line is preferably defined by a line of weakness obtained on the blank, such as for example a crease, or an incision or a plurality of aligned holes.

Within the scope of the present invention two surfaces are to be considered misaligned when they are not parallel; specifically a misalignment between two surfaces is considered compensated when at least one of the two surfaces is oriented so as to be parallel to the other.

"Longitudinal direction" of an element means the direction along which the element is predominantly extended.

The Applicant has preliminarily observed that the wrap-around type packaging process briefly illustrated above allows to obtain significant advantages in terms of production flexibility compared to the packaging process with insertion of the article in the preformed box. In fact, in the wrap-around type packaging process, the times to switch from one format to another or to bring new formats into production are significantly reduced.

However, the Applicant has observed that the wrap-around type packaging process described above is often particularly complex and articulated, particularly when the articles contain delicate or crumbly products, like in the case of bags containing corn flakes. In fact, the latter can easily break forming crumbs and powders that lower the quality of the end product.

In particular, the Applicant has observed that one of the critical steps for packaging articles into a box by the wrap-around type packaging process is the closure of the blank once it is wrapped around the mandrel. This closure provides for a series of distinct operations, such as folding the flaps along a corresponding folding line and gluing them onto each other, which in turn provides not only that the two flaps are in their desired final relative position, but that they are kept in that position for the time necessary for the adhesive to effectively exert its function, i.e. that the two flaps no longer move with respect to each other.

These operations may generally provide that these flaps have an appropriate abutment element.

The Applicant was able to assess that the folding of the flaps onto each other along the corresponding folding line to overlap at least partially the flaps and their gluing onto each other cannot take place by folding the flaps and pressing them against the products, that is using the products as abutment elements, in particular when such articles are delicate or crumbly.

The Applicant has also observed that these operations of folding the flaps and of gluing the flaps themselves are typically carried out by different members, which make both the process and the plant for the wrap-around type packaging little flexible and complicated both from the realization and management point of view.

The Applicant has therefore felt the need to modify the plant for the wrap-around type packaging and the relative process taking into account that a simplification of the packaging operations could not, however, have dispensed with safeguarding the integrity of the articles to be packaged.

In response to this need, the Applicant has found that a device and a method for the packaging of articles into boxes that provide that the operations of folding the flaps and of gluing the flaps onto each other are carried out by a single closing group against a mandrel greatly simplifies the wraparound process and the relative packaging plant.

However, the Applicant has found that such a packaging device and relative packaging method may be affected by possible misalignments between the closing group and the mandrel.

Such misalignments can lead to accidents during the functioning of the packaging device, premature wear of some of its components, lack of closure or incorrect closure of the blank wrapped around the mandrel.

The occurrence of accidents during the operation of the device may involve damages to the device itself and/or to the articles intended for packaging and/or to any packaging personnel and such accidents generally require, as well as the wear of the components of the device, stopping production for the time necessary to resolve the accident and/or restore the correct functioning of the device.

The lack of closure and the incorrect closure of the blank wrapped around the mandrel may instead entail the need to discard the package obtained from this blank and possibly recover the articles contained therein to introduce them back into the packaging process. The Applicant has also noted that even very small misalignments are sufficient to obtain incorrect closures. He has also noted that such misalignments are difficult to avoid over time, since the mandrel and the relative closing group are in continuous movement, so that frequent and delicate operations for adjusting the mutual position between mandrel and closing group are necessary. The Applicant has realised that the issue could be solved by ensuring that the abutting element of the closing group, intended to abut with a contact surface thereof the mandrel during the step for closing the outer flap against the inner flap of the blank, was able to self-adjust its position with respect to the mandrel.

The Applicant has therefore found that a packaging device and method in which the abutting element is equipped with one or more compensating elements capable of automatically compensating for any misalignments between its contact surface and the mandrel would have made it possible to considerably improve the quality of the closure of the box and more generally the plant for wrap-around type packaging as a whole and the relative packaging process.

In a first aspect thereof, therefore, the present invention is directed to a packaging device for packaging articles in boxes comprising a mandrel and a closing group.

Preferably said mandrel is configured to accommodate one or more of said articles therein.

Preferably said mandrel is adapted to be at least partially wrapped by a blank so as to form a partially closed box.

Preferably the closing group is arranged to at least partially overlap and fix an outer flap of the blank onto an inner flap of the blank when the blank is at least partially wrapped on the mandrel. Preferably said closing group comprises an abutting element movable with respect to the mandrel. Preferably said abutting element is movable with respect to said mandrel between a rest position, in which the abutting element is in a remote position with respect to the mandrel, and a pressing position, in which the abutting element is in a position such as to press the outer flap on the inner flap and against an abutment surface of said mandrel.

Preferably said closing group comprises a displacement member.

The displacement member may be any mechanism capable of moving the abutting element between the rest position and the pressing position along a predetermined path and is represented by a conveyor driven by electric, mechanical, hydraulic or pneumatic motors or other similar systems capable of moving the abutting element along a trajectory. An example of a displacement member is robotic arms.

Preferably said displacement member is configured to displace the abutting element between the rest position and the pressing position.

Preferably the abutting element comprises at least one contact surface intended to abut the mandrel, more preferably the abutting element comprises at least one contact surface intended to abut the mandrel at the abutment surface.

Preferably the abutting element comprises one or more compensating elements.

Preferably such one or more compensating elements are configured to compensate for a misalignment between the abutment surface of the mandrel and the at least one contact surface of the abutting element.

Preferably such one or more compensating elements are configured to compensate for a misalignment between the abutment surface of the mandrel and the at least one contact surface of the abutting element such that, in the pressing position, the abutment surface of the mandrel and the at least one contact surface of the abutting element are parallel to one another.

In a second aspect thereof, the present invention comprises a method for packaging articles in boxes comprising step a) of arranging a blank at least partially around a mandrel.

Preferably step a) provides for arranging a blank at least partially around a mandrel so as to form a partially closed box around said mandrel.

Preferably step a) provides for arranging a blank at least partially around a mandrel in such a manner that the blank has two flaps, an outer flap and an inner flap.

Preferably the outer flap is at least partially overlappable on the inner flap.

Preferably the two flaps are fixable on each other when pressed against each other.

Preferably, said mandrel contains one or more of said articles therein.

Preferably the method for packaging articles in boxes comprises the step b) of arranging an abutting element movable with respect to the mandrel between a rest position, in which the abutting element is in a remote position with respect to the mandrel, and a pressing position, in which the abutting element is in a position such to press the outer flap.

Preferably in said pressing position the abutting element is in a position such to press the outer flap on the inner flap.

Preferably in said pressing position the abutting element is in a position such to press the outer flap on the inner flap and against an abutment surface of said mandrel.

Preferably said abutting element comprises at least one contact surface intended to abut the mandrel at said abutment surface.

Preferably the method for packaging articles in boxes comprises step c) of folding the inner flap at least partially towards the mandrel.

Preferably the method for packaging articles in boxes comprises step c) of folding the inner flap at least partially towards the abutment surface of said mandrel;

Preferably the method for packaging articles in boxes comprises step d) of folding the outer flap on the inner flap and against said abutment surface of said mandrel.

Preferably the method for packaging articles in boxes comprises step e) of pressing the outer flap onto the inner flap and against said abutment surface of said mandrel.

Preferably the method for packaging articles in boxes comprises step e) of pressing the outer flap on the inner flap and against said abutment surface of said mandrel by moving the abutting element to the pressing position.

Preferably the at least one contact surface of the abutting element is arranged parallel to the abutment surface of the mandrel.

Preferably the at least one contact surface of the abutting element is arranged parallel to the abutment surface of the mandrel as a result of said pressing.

Preferably the at least one contact surface of the abutting element is arranged parallel to the abutment surface of the mandrel as a result of said pressing, so as to exert a substantially uniform pressure on said outer flap and inner flap.

It will be appreciated that it is thus possible to obtain automatically that the abutting element is arranged parallel to the abutment surface of the mandrel; in fact the abutting element, if there is a misalignment between the abutment surface of the mandrel and the at least one contact surface of the abutting element itself, is able to self-adjust in such a way as to orient said contact surface parallel to the abutment surface of the mandrel thanks to the presence of said compensating elements, avoiding or limiting the issues deriving from the misalignment of said surfaces.

Of course this compensation mechanism exerts its function only when there is a misalignment between the abutment surface of the mandrel and the at least one contact surface of the abutting element.

The present solution, in at least one of the aforementioned aspects, may have at least one of the further preferred features set forth below.

In some embodiments the abutment surface of the mandrel and the at least one contact surface of the abutting element are flat.

In some embodiments the compensating elements comprise joints and/or elastically deformable elements.

This allows in a simple and effective way to compensate for any misalignment between the abutment surface of the mandrel and the at least one contact surface.

Preferably said elastically deformable elements comprise springs, such as for example spiral springs and gas springs, and/or cylinder-piston members and/or inserts of polymeric material.

In some preferred embodiments said elastically deformable elements comprise cylinder-piston members, preferably pneumatic cylinder-piston members. In some embodiments such cylinder-piston members are connected to a compressed air circuit so as to keep such at least one contact surface pressed on such overlapped outer flap and such inner flap of the blank against the abutment surface of the mandrel.

Preferably said cylinder-piston members are connected to a compressed air circuit so as to keep such at least one contact surface of the abutting element pressed on such overlapped outer flap and such inner flap of the blank against the abutment surface of the mandrel with a predetermined pressure.

Preferably said joints are ball joints and/or hinges.

In some embodiments the compensating elements are at least two.

Advantageously, this makes it possible to compensate much more efficiently for any misalignments between the two surfaces.

In a preferred embodiment, the compensating elements are distributed along a longitudinal direction of the abutting element.

It will be appreciated that this technical feature makes it possible to efficiently compensate for any misalignments between the two surfaces in particular when the abutting element has a longitudinal dimension particularly greater than the other dimensions, i.e. when the abutting element has an elongated shape in the longitudinal direction.

In some embodiments the abutting element comprises a support element engaged to the displacement member and to at least one contact element, the at least one contact surface belonging to said at least one contact element and said one or more compensating elements being interposed between the support element and said at least one contact element.

In some embodiments the compensating elements are positioned at the opposite end regions of said contact surface.

It will be appreciated that, on the basis of these characteristics, the abutting element presses the outer flap on the inner flap and against the abutment surface of the mandrel in particular in the end regions of the flaps themselves, where it is usually more important that they are fixed on each other.

Preferably said at least one contact surface belongs to a contact element distinct from said compensating elements.

This allows to further optimise the management and maintenance of the plant; for example, any particles and/or smears of glue used to fix the flaps on each other and ended up on the surface of the outer flap on which the abutting element acts may end up on the contact element but not on the compensating elements. In this way the operation of the compensating elements is preserved.

In some embodiments the contact element is a plate, preferably metallic. This technical measure makes any operation for cleaning the contact element from such particles and/or smears of glue extremely simple.

In some embodiments the compensating elements are adapted to keep said at least one contact surface pressed on said outer flap and said inner flap overlapped on the blank against the abutment surface of the mandrel with a predetermined pressure.

This technical measure ensures on the one hand an adequate gluing of the flaps and on the other hand it does not exert on the mandrel a pressure higher than necessary.

In some embodiments said device for packaging articles in boxes comprises a moving unit of the mandrel configured to move the mandrel.

In some embodiments, said mandrel is moved by said moving unit along a movement plane and said abutting element is moved between said rest position, said folding position and said pressing position along a trajectory incident with said movement plane.

Preferably, the closing group is mounted on such a moving unit.

By moving unit it is meant any mechanism capable of moving the mandrel along a predetermined path and can be represented by a conveyor driven by mechanical, pneumatic or hydraulic electric motors or other similar known systems capable of moving the mandrel along any trajectory, for example straight, curvilinear, closed-loop, circular.

Examples of moving units are conveyor belts, robotic arms and carousels.

In some preferred embodiments the moving unit is configured to move both the mandrel and the closing group along a predetermined path. Preferably said predetermined path is, at least in a portion thereof corresponding to the displacement of the abutting element from the rest position to the pressing position and vice versa, circular. In this case, the movement plane of the mandrel is represented by the plane containing the portion of circular path.

Preferably, the mandrel in its displacement along the predetermined path defines a direction of advancement and, in one embodiment, the trajectory along which said abutting element is displaced from the rest position to the pressing position, comprises a component concordant with said direction of advancement of the mandrel.

In some embodiments, the moving unit is configured to move both the mandrel and the closing group.

Preferably the moving unit comprises a carousel, more preferably it is a vertical axis carousel. More preferably, the carousel is arranged to move both the mandrel and the closing group along a circular path.

In some embodiments the packaging device for packaging articles into boxes comprises a plurality of mandrels and a closing group for each mandrel. Preferably the outer flap and/or the inner flap are at least partially separated from the rest of the blank by a folding line.

Preferably the outer flap and/or the inner flap are folded along a folding line thereof.

Preferably the outer flap and/or the inner flap are folded along a folding line thereof by the closing group.

In some embodiments, the folding line is formed by a crease or by an incision line or by a line of holes obtained on the blank.

In this way the folding of the flap along the folding line is particularly facilitated.

In a preferred embodiment, at least one of said two flaps bears an adhesive on an overlapping surface with the other flap.

In some embodiments, the adhesive is a glue.

In one embodiment, the adhesive is a glue and in step e) the abutting element presses, in the pressing position, the outer flap on the inner flap and against the abutment surface of the mandrel, preferably for a time equal to or longer than the drying time of the glue.

In this way the box is closed permanently, avoiding issues of detachment or insufficient adhesion. In some embodiments, the abutting element presses, in the pressing position, the outer flap on the inner flap and against the mandrel with a predetermined pressure.

This technical measure allows to optimally control the pressure applied, ensuring that it is sufficient for gluing but not such to damage the mandrel itself.

In some embodiments, the blank is preliminarily at least partially creased.

This makes the closing process easier to execute.

Preferably, the blank is creased at the upper flap and/or the lower flap, more preferably at both flaps.

In this way the closing process is less prone to errors, such as an erroneous overlap of the upper and lower flaps.

In some embodiments step c) is performed at least partially concurrently with step d) but before the abutting element is in the pressing position.

This allows shortening the packaging times, while maintaining a sequence of steps suitable for the packaging of articles into boxes.

In some embodiments, the abutting element, in the passage from the rest position to the pressing position, completes the folding of the inner flap against the mandrel.

With this measure, both the packaging process is simplified, which does not provide that the inner flap is kept against the mandrel during the folding of the outer flap on the inner flap and against the mandrel, and any preliminary treatments of the blank, whose inner flap does not necessarily have to be preliminarily already folded in the position that it has once glued with the upper flap.

In some embodiments, a step of returning the movable abutting element from the pressing position to the rest position after step e) is provided.

In such a case, the step of returning the movable abutting element from the pressing position to the rest position does not necessarily occur along a single trajectory, nor is such trajectory necessarily the same as the one for moving the abutting element from the rest position to the at least one folding position and from the at least one closing position to the pressing position.

In some embodiments, it is the displacement member that brings the movable abutting element from the pressing position back to the rest position after step e).

It should be noted that some steps of this method may be independent of the order of execution reported. In addition, some steps may be optional. In addition, some steps of the methods may be performed repetitively, or they may be performed in series or in parallel with other steps of the method.

The characteristics and advantages of the present solution will become clearer from the detailed description of a preferred embodiment thereof, by way of non-limiting example, with reference to the appended drawings wherein:

- Figure 1 is a partial schematic and perspective view from above of an example of packaging device for packaging articles in boxes made in accordance with this solution;

- Figure 2 is a schematic view of a blank;

- Figure 3 is a partial schematic and left side perspective view of a detail of the packaging device for packaging articles in boxes of Figure 1 ;

- Figure 4 is a partial schematic view and right side perspective view of the detail of Figure 3;

- Figure 5 is a partial schematic and left side perspective view of a detail of Figure 3;

- Figure 6 is a partial schematic view and right side perspective view of the detail of Figure 5;

- Figure 7 is the same view as Figure 5 in which some elements are represented in transparency;

- Figure 8 is the same view as Figure 6 in which some elements are represented in transparency, and

- Figures 9a to 9f are respective schematic representations of a method for packaging articles in boxes made in accordance with this solution.

With initial reference to Figure 1 , an example of a packaging device made in accordance with this solution is indicated as a whole with 100. The packaging device 100 is arranged to package one or more articles 1 into boxes 2.

The articles 1 are, in this preferred embodiment example, bags of granular, loose or bulk food products, for example corn flakes, in particular bags with a longitudinal dimension of about 300 mm (exemplary value).

The packaging device 100 comprises a plurality of mandrels 10 and a moving unit 50 for moving such mandrels 10. Such a moving unit 50 comprises a carousel 51 rotatable around a vertical axis. The moving unit 50 moves the plurality of mandrels 10 along a displacement direction F defining a substantially circular path.

Each mandrel 10 has its own closing group 30; each closing group 30 is mounted on the moving unit 50, so that said moving unit 50 moves both each mandrel 10 and the corresponding closing group 30 along the displacement direction F.

The mandrel 10 is configured to accommodate one or more such articles 1 therein. It is furthermore adapted to be wrapped at least partially by a blank 20 of cardboard so as to form a partially closed box 210.

The blank 20, an example of which is shown in Figure 2, provides a series of panels 23 adapted to form the sides of the box 2 and of the flaps 24,241,242 adapted to overlap with other flaps 24,241,242.

The flaps 24,241,242 and the panels 23 may be creased along a folding line 25,251,252 so as to be more easily folded to form the box 2.

In particular, the blank 20 is shaped such that, once wrapped at least partially around the mandrel 10, the two flaps 241,242 are overlappable on each other when folded towards each other along the corresponding folding line 251,252.

The blank 20 is shaped such that, once wrapped at least partially around the mandrel 10, the two flaps 241,242 overlap on each other abutting the mandrel 10 on an abutment surface 10a thereof, as shown in Figure 9e.

The flap 241, once this overlap has been made, will be located outside the partially closed box 210; this flap 241 is the so-called outer flap 241.

In a completely similar way, the flap 242, once such an overlap has been made, will be located between the outer flap 241 and the inside of the partially closed box 210; such flap 242 is the so- called inner flap 242.

At least one of the two flaps 241,242 also bears an adhesive 40 on an overlapping surface 222 with the other flap 241,242.

The adhesive 40 is a glue 41 distributed in glue points 411.

Still with reference to Figure 2, the glue points 411 are spaced apart stepwise along an axis X parallel to the folding lines 251 and 252.

In some embodiment variants, the glue points 411 can only be located at the end regions of the flaps 241,242.

Still with reference to Figure 2, it is the outer flap 241 that bears, on its overlapping surface 222, such glue points 411.

Figures 3 and 4 relate to a detail of the packaging device 100 in which the closing group 30 and the mandrel 10 are visible.

Each closing group 30 comprises a displacement member 32 and an abutting element 31 movable with respect to the mandrel 10 between a rest position in which the abutting element 31 is in a remote position with respect to the mandrel 10 and a pressing position, in which the abutting element 31 is in a position such to press the outer flap 241 on the inner flap 242 and against an abutment surface 10a of the mandrel 10.

The displacement member 32 moves the abutting element 31 between the rest and pressing positions.

Said displacement member 32 comprises an articulated arm 321 that actuates the displacement of the abutting element 31 between the rest and pressing positions.

With reference to Figures 5-8, the abutting element 31 comprises a support element 311 engaged to the displacement member 32, two compensating elements 312, in particular two cylinder-piston members 312a as visible in Figures 7 and 8, and a contact element 313, in particular a plate 3131 having a contact surface 3131a intended to abut the mandrel 10 in its abutment surface 10a.

Such cylinder-piston members 312a are located between the support element 311 and the plate 3131 at the opposite end regions of the contact surface 3131a of the plate 3131.

The contact surface 3131a of the plate 3131 has a longitudinal extension at least equal to or greater than the longitudinal length of the abutment surface 10a of the mandrel 10.

The abutting element 31 , in passing from the rest position to the pressing position, approaches the mandrel 10 from the side of the outer 241 and inner 242 flaps of the blank 20 until it meets the outer flap 241.

Continuing its approach towards the mandrel 10, the abutting element 31 folds the outer flap 241 against the mandrel 10 along a corresponding folding line 251. The outer flap 241, by folding against the mandrel 10 along the folding line 251, meets the inner flap 242, which is already preliminarily at least partially folded along a corresponding folding line 252 towards the mandrel 10 itself.

Continuing further its approach to the mandrel 10, the abutting element 31 continues to fold the outer flap 241 towards the mandrel 10; in turn the outer flap 241, in its folding movement, further folds the inner flap 242 against the mandrel 10 until it abuts the mandrel 10 itself on an abutment surface 10a thereof.

The approach of the abutting element 31 to the mandrel 10 from the rest position to the pressing position takes place with a straight trajectory D that is inclined with respect to the abutment surface 10a of the mandrel 10.

As soon as the abutting element 31, and in particular the plate 3131 with its contact surface 3131a, contacts the mandrel 10 on its abutment surface 10a, by pressing the outer flap 241 on the inner flap 242 and against the abutment surface 10a, the two cylinder-piston members 312a orient the abutting element 31 in such a manner that the contact surface 3131a and the abutment surface 10 abut so as to be parallel.

In this way, any misalignments between the abutment surface 10a of the mandrel 10 and the abutting element 31 are corrected in the pressing position.

Moreover, with this solution the pressure of the abutting element 31 is homogeneously distributed on the upper flap 241 overlapped on the lower flap 241 and against the mandrel 10.

Finally, Figures 9a to 9f illustrate different steps of the method according to the innovation.

Figure 9a shows the blank 20 partially wrapped around the mandrel 10 to form a partially closed box 210.

The mandrel 10 contains one or more articles 1 therein; with reference to Figures 9a-9f, only one article 1 is depicted.

The blank 20 partially wrapped around the mandrel 10 to form a partially closed box 2 210 has two partially overlappable flaps 241,242, the outer flap 241 and the inner flap 242.

Figure 9b depicts the step in which the inner flap 242 is at least partially folded towards the mandrel 10 along the corresponding folding line 251.

Figure 9c depicts the step in which the abutting element 31 is in a remote position with respect to the mandrel 10 and is about to move along a straight trajectory D that is inclined with respect to an abutment surface 10a of the mandrel 10 by an angle of about 30°.

Figure 9d depicts a step in which the abutting element 31 passes from the rest position, represented in Figure 9c, to the pressing position, represented in the corresponding Figure 9e, moving along the straight trajectory D; the abutting element 31 in its movement along the straight trajectory D, folds the outer flap 241 along the corresponding folding line 251 towards the abutment surface 10a of the mandrel 10. During the folding thereof by the abutting element 31, the outer flap 241 meets the inner flap 242 and completes the folding thereof along the corresponding folding line 252 until it abuts the abutment surface 10a of the mandrel 10.

As soon as the abutting element 31 touches the outer flap 241 on the inner flap 242 against the abutment surface 10a of the mandrel 10, the compensating elements 312, not depicted in Figures 9a-9f, make sure that the contact surface 3131a of the abutting element 31 and the abutment surface 10a of the mandrel 10 abut one another so as to be parallel; in particular the compensating elements 312 orient the contact surface 3131a of the abutting element 31 so that it is parallel to the abutment surface 10a of the mandrel 10 ensuring a homogeneous pressure on the overlapped flaps 241,242 and against the mandrel 10.

Subsequently, the closing group 31 can possibly return to the rest position with respect to the mandrel 10 (Figure 9f).

It goes without saying that, in order to meet specific and contingent application needs, a person skilled in the art will be able to make further modifications and variants to the solution described above that are nevertheless within the scope of protection as defined by the following claims.