IT201600101958A1 - METHOD AND MACHINE FOR PACKAGING PAPER ROLLS, AND PACKAGING OBTAINED - Google Patents

Description

Method and machine for wrapping paper rolls, and packaging obtained

DESCRIPTION

TECHNICAL FIELD

The present invention relates to improvements in machines and methods for producing packs of rolls, in particular but not exclusively rolls of tissue paper, such as rolls of toilet paper, kitchen paper and the like. The invention also concerns improvements to the packaging of the aforementioned products.

ANTERIOR ART

Rolls of tissue paper, for example toilet paper, kitchen paper and the like, are usually packaged in sheets of plastic material, that is, in polymeric film. A plurality of rolls are arranged to form a geometrically ordered grouping, with one or more rows of rolls, each of which comprises one or more overlapping rolls. These ordered groups of rolls are wrapped in a sheet of wrapping which laterally surrounds the group of rolls and which has flaps folded against the substantially flat opposite faces formed by the flat faces of the rolls and welded together.

Machines for wrapping groups of rolls in wrapping sheets are described for example in US 6308497, US 7707805, US 7703264, US 2014/0260087, and in US 8430232, EP1067048, EP1312549, EP1992562, US8727106, US7654386.

The edges of the wrapping sheet overlapping and overturned on the substantially flat faces of the group of rolls are welded by means of a heat sealing device. Examples of welding devices are described in US 2004/0151481 and in EP 2213577, EP1539586.

The substantially flat and opposite faces of the packages thus obtained have irregular surfaces due to the thermal deformations of the plastic film caused by heat sealing. The sealed area remains exposed and in some cases can be damaged due to the manipulations to which the packages are subject.

In some cases, welding defects can occur. If the sealing is incomplete, the package obtained is not sealed, but may have imperfections and openings. This can occur, for example, in the case of insufficient soldering temperatures. In other cases, excessive sealing temperatures can cause perforation of the plastic film with which the wrapping sheet is made. The wrapping sheet is usually printed, for example silk-screened, with the manufacturer's trademarks, with decorations, or with other technical or advertising information. Printing on the plastic film must be limited to that area of the film that wraps around the side surface of the package, while the flaps that fold and overlap on the substantially flat and opposite faces of the package must tend to be free of prints, as these areas are welded.

Packages of this type therefore have some drawbacks linked to the configuration of the sealing areas.

SUMMARY OF THE INVENTION

According to a first aspect, a package of tissue paper rolls is provided, comprising a geometrically ordered group of rolls and a wrapping sheet which laterally wraps the geometrically ordered group of rolls and forms folded flaps on two substantially flat and opposite faces of the package. The package also provides that an adhesive sheet is applied to said folded edges of at least one of the two substantially flat and opposite faces.

The substantially flat surface is in practice formed by the flat and exposed face or faces of the roll or rolls forming the geometrically ordered group of rolls.

The geometrically ordered group of rolls can also comprise a single roll. Preferably, the geometrically ordered group of rolls comprises a plurality of rolls, arranged in two or more rows and on one or more layers.

Preferably, the folded flaps are superimposed on each other and can be welded together. In other embodiments, the adhesive sheets can serve to secure the folded flaps.

Preferably, the adhesive sheets are applied on both substantially flat and opposite faces.

The adhesive sheet or each adhesive sheet advantageously covers an extended surface of the flat face, for example at least 30%, preferably at least 70%, more preferably at least 80% of the surface of the respective substantially flat face.

The adhesive sheet can be used to fix the edges of the wrapping sheet and / or to cover the sealing area of the folded and overlapping edges, for example for aesthetic reasons, to cover any welding defects, such as holes or areas not completely welded. Furthermore, the adhesive sheets can be printed, so as to complete the printing of the wrapping sheet, normally provided on the lateral surface of the package.

According to some embodiments, the package comprises a grip handle. The gripping handle can be formed by an elongated element, for example a strip of plastic film, paper, cardboard or other material, adhesively fixed between the adhesive sheet and the wrapping sheet that wraps the rolls. For example, the elongated element can have two ends fixed between the adhesive sheet and the substantially flat face of the package.

In other embodiments, the handle can be formed from the same adhesive sheet, instead of being constituted by a further and separate element, which is adhesively fixed to the package by means of the adhesive sheet. For example, the handle can be formed by incisions or cuts made in a central non-adhesive area or portion of the adhesive sheet. In other embodiments the adhesive sheet can be folded to form one or two wings adhesively applied to the substantially flat face, and a protruding portion or two protruding and folded portions, forming a handle. Gripping can be facilitated by providing cutouts, holes or cutouts in the sheet.

According to a further aspect, a method is provided for producing a package of rolls comprising the steps of:

forming a geometrically ordered group of one or more rolls; wrapping a sheet of wrapping around the geometrically ordered group of rolls and folding and overlapping edges of said wrapping sheet on two substantially flat and opposite faces defined by the geometrically ordered group of rolls.

The method further comprises the step of applying an adhesive sheet to at least one of the substantially flat and opposite faces.

According to a still further aspect, a machine is provided for the production of packages of rolls comprising:

a wrapping station, configured and arranged to wrap a geometrically ordered group of rolls in a wrapping sheet, forming folded and superimposed flaps of said wrapping sheet on two substantially flat and opposite faces of said geometrically ordered group of rolls;

along a path of advancement of the geometrically ordered groups of rolls, downstream of the winding station with respect to a direction of advancement of the geometrically ordered groups of rolls along the path of advancement, a station for applying adhesive sheets on at least one of said two faces substantially flat and opposite.

A package of tissue paper rolls is also described here, comprising:

- a geometrically ordered group of one or more rolls;

- a sheet of wrapping that wraps laterally the geometrically ordered group of one or more rolls and forms folded flaps on two substantially flat and opposite sides of the package

characterized in that on at least one of the two substantially flat and opposite faces an adhesive sheet is applied which forms a handle or through which a handle is applied on the substantially flat face.

Further characteristics and embodiments of the method, of the machine and of the package are described below and in the attached claims, which form an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by following the description and the attached drawing, which shows practical embodiments. More specifically, in the drawing:

Fig.1 illustrates a plan view of a portion of the packaging line in which machines according to the invention are inserted;

Fig.2 shows an enlargement of a head for applying the adhesive sheets to the package;

Figs. 3A to 3H illustrate a sequence showing the formation of a package according to the method described here;

Fig.4 illustrates another embodiment of the package; Figs. 5A-5F illustrate other embodiments of the package with a grip handle.

DETAILED DESCRIPTION OF FORMS OF CONSTRUCTION

The following detailed description of exemplary embodiments refers to the accompanying drawings. The same reference numerals in different drawings identify the same or similar elements. Also, the drawings are not necessarily to scale. Furthermore, the detailed description that follows does not limit the invention. Rather, the scope of the invention is defined by the attached claims.

Reference throughout the description to "an embodiment" or "the embodiment" or "some embodiment" means that a particular feature, structure or element described in connection with an embodiment is included in at least one embodiment of realization of the described object. Therefore the phrase "in an embodiment" or "in the embodiment" or "in some embodiment" at various points along the description does not necessarily refer to the same or the same embodiments. Furthermore, the particular features, structures or elements can be combined in any suitable way in one or more embodiments.

Fig.1 schematically shows a plan view of the end part of a production line for packs of rolls of web material, for example tissue paper. In the portion of the line represented in Fig. 1, 1 indicates the station in which the winding of each geometrically ordered group of rolls is carried out in a wrapping film, hereinafter briefly referred to as the wrapping station. The wrapping station 1 can comprise a sealing unit 1A which carries out the sealing of the folded overlapping edges of the wrapping sheet. The winding station 1 and the welding unit 1A can be made in a known way, for example as described in the patents cited in the section dedicated to the current art of the present description.

Reference 3 indicates a path of advancement of the packages obtained from station 1 towards a station 2 which can comprise a known type of bagging machine ("bundler"), in which a plurality of packages are inserted into larger bags for subsequent transport . F indicates the direction of advancement of the packages from station 1 to station 2.

Characteristically, downstream of the wrapping station 1, between it and the bagging machine there is a station 5 for applying adhesive sheets on the opposing substantially flat and opposing faces of the package produced by the wrapping station 1.

In the embodiment of Fig.1, the adhesive sheet application station 5 comprises four operating heads indicated by 7A, 7B, 9A, 9B, arranged in pairs on opposite sides of the advancement path 3. The four heads are substantially mutually identical and one of them is shown in the enlargement of Fig. 2. In the embodiment illustrated in Fig.1, four heads are provided to allow the station 5 for applying the adhesive sheets to work continuously, even during the replacement of the consumable materials, i.e. the adhesive sheets that the station applies to the packages in transit through of it. More specifically, the heads 7A, 7B, 9A, 9B are arranged so that while the heads 9A, 9B of one pair are in operation, the heads 7A, 7B of the other can be stationary to allow the removal of the exhausted coils. of consumable material, i.e. adhesive sheets, and their replacement with new reels. In other embodiments, a single pair of heads 7A, 7B, or 9A, 9B can be provided, in which case the line stops to change the consumable material.

In some embodiments it can be envisaged to have two or more pairs of heads, and to use at least two pairs of heads simultaneously, making them work alternately, i.e. using for example a first pair to apply the adhesive sheets on the even-numbered packs. and the other pair for applying adhesive sheets to the odd place packages in the flow of packages coming from the wrapping machine 1. More generally, one pair of heads applies the adhesive sheets on some packages and the other pair of heads applies the adhesive sheets on the remaining packages. This can be useful, for example, if you want to equip the packs with adhesive sheets of two different types. The concept can be extended to a greater than two number of pairs of heads and therefore to a greater than two number of adhesive sheets that are different from each other.

In this case, in order to change the consumable material, it is possible to provide a number of pairs of heads which is redundant with respect to the number of pairs simultaneously in operation. For example, it is possible to provide three pairs of heads, two in operation and one in waiting, which is loaded with the consumable material and replaces, of the two pairs in operation, the first which runs out of consumable material. In this way, total redundancy (ie four pairs of heads) is not necessary.

The possibility of using heads that are able to change the consumable material on the fly is not excluded.

Fig.2 schematically illustrates an enlargement of one of the heads 7A-9B, which are substantially identical to each other. Reference B1 indicates a reel on which a support tape is wound onto which adhesive sheets are applied in a removable manner to be applied to the packages in transit through the station 5 for applying the adhesive sheets. B2 indicates a reel on which the exhausted support tape is wound, ie from which the adhesive sheets have been detached to be transferred to the packages through the station 5 for applying the adhesive sheets.

In practical embodiments the heads 7A-9B are labeling heads of suitable dimensions.

Each head 7A-9B comprises an applicator blade 11 arranged with its own free end close to the substantially flat faces of the packages C which advance along the advancement path 3. A support tape N unwound from the reel B1, and on which adhesive sheets are applied E detachable, it is returned around the corner or distal edge of the applicator blade 11, so that, by synchronizing the advancement movement of the support tape N with the advancement of the packages C along the path 3, the adhesive sheets E detach from the tape N and are transferred to the respective substantially flat face of the package C, near which the distal edge of the respective blade 11 is placed. The adhesive present on each adhesive sheet E causes the adhesive sheet E to be glued to the flat face of the package. By placing two heads on the two opposite sides of the feeding path 3, adhesive sheets or labels E are applied to both flat and substantially opposite sides of the package C.

Unlike what is shown in Fig. 1, in other embodiments only one pair of operating heads 7A, 7B can be provided. In this case, the replacement of consumables requires the temporary shutdown of the production line. An accumulation buffer for the packages or individual rolls may be provided upstream of the station 5 for applying the adhesive sheets.

While two opposing adhesive sheets are preferably applied to each package, one on each flat face, the possibility of applying said adhesive sheets to only one of these faces is not excluded.

The adhesive sheets E are equipped with a pressure adhesive. Any known type pressure adhesive, suitable for adhering to the material of which the wrapping sheet F1 is made, can be used. In some embodiments, to improve adhesion, downstream of the zone for transferring the adhesive sheet E from the support tape N to the package C, a pressure system can be provided, for example comprising a rubber-coated roller, as schematically indicated with 12 in Fig. 2. Instead of a roller, any other pressure system can be provided, for example a sliding shoe, although a roller is currently preferable as it does not hinder the regular advancement of the packages along the advancement path 3.

The production method of the packs of rolls is illustrated in detail in the sequence of Figs.3A-3G. These figures show only: the rolls to be packaged indicated with R, the wrapping sheet with which the package is formed, and the adhesive sheets E applied in the station 5 for applying the adhesive sheets. The mechanical members of the various stations mentioned above are omitted, as they are known or described with reference to Figs. 1 and 2.

In Fig.3A an initial phase is shown, in which a geometrically ordered group G of rolls R is wrapped with a wrapping sheet F1, typically a plastic film. In the illustrated embodiment, the geometrically ordered group G of rolls R has a matrix of 2x4 rows of rolls, where each row contains 3 rolls. It is to be understood that this configuration is merely exemplary and that the number and arrangement of the rolls R in the geometrically ordered group G may be different from those illustrated. Relevant is only the fact that the geometrically ordered group G of rolls R has two substantially flat and opposite faces, defined by the flat faces of the various rolls R exposed on the two sides of the package.

In Fig.3B the next phase is shown in which the wrapping sheet F1 has been completely wrapped around the lateral surface of the geometrically ordered group G of rolls R, overlapping two edges L1, L2 parallel to the axes of the rolls R. These edges can be welded together in a way known per se.

The wrapping sheet F1 has a width H greater than the height of each row of rolls R, so that two opposing portions of wrapping sheet F1 protrude from the geometrically ordered group G of rolls R. These portions are folded to form flaps F2 which are folded and overturned against the substantially flat and opposite side faces of the geometrically ordered group G of rolls R. The folded flaps are superimposed on each other, see Figs.3C, 3D and 3E.

In Fig.3F the package C formed by the geometrically ordered group G of rolls R and by the wrapping sheet F1 that wraps them is shown. The package C, not yet complete, leaves the wrapping machine 1 in this configuration.

The package thus made can be passed through the sealing unit 1A of the wrapping station 1. The sealing unit 1A has sealing members which cause the heat sealing of the folded and superimposed edges F2 on the two opposite substantially flat and opposite faces of the package C.

In some embodiments, the welding assembly 1A can be omitted. In embodiments of the method, the welding assembly can be deactivated. In the case in which the sealing unit 1A is not provided, or this unit is deactivated, it is possible to use wrapping sheets of non-thermoplastic material, for example paper, whose wrapping folds are stabilized with the use of adhesive sheets E. In particular, in this case the package C can be formed by a single roll R and therefore the geometrically ordered group is constituted by a single roll of paper.

If the welding unit 1A is not provided or is deactivated, between the latter and the area of application of the adhesive sheets E, that is, in the area where the blades 11 of the heads 7A-9B are located, containment elements can be provided for the flaps folded and overlapped F2, to prevent them from reopening. For example, feed belts can be provided which remain in contact with the substantially flat and opposite faces of the package C. Alternatively, stationary surfaces, for example stationary foils, preferably made of or coated with a low coefficient of friction material, such as Teflon® or similar. In this case the packages slide along the stationary foils and in contact with them.

In the station 5 for applying the adhesive sheets to the two opposite substantially flat faces of the package C, two adhesive sheets E are applied, as schematically illustrated in Figs.3G and 3H.

Fig.3H illustrates the finished package C, complete with adhesive sheet E applied to the substantially flat face in view. A similar adhesive sheet E is applied to the opposite face (not visible in Fig.3H). The two adhesive sheets E applied to the two opposite substantially flat and opposite faces of the package C can be the same or different from each other. For example, they can be of a different shape or of a different size. In some cases, one or the other of the two adhesive sheets E can be printed. In this case, the prints on the two adhesive sheets E of the same package may be different.

Preferably, each adhesive sheet E has a sufficiently extended surface to cover most of the area of the corresponding substantially flat face on which the adhesive sheet E has been applied. For example, the sheet E can reach the lateral edges of this substantially flat face. The adhesive sheet E can also have a shaped edge to follow the rounded shape of the substantially flat face on which it has been applied, the rounding being present in the corners and being determined by the cylindrical shape of the packaged rolls.

Each adhesive sheet E serves to cover the overlapping F2 flaps, so as to protect them and prevent their wrinkled appearance from giving an aesthetically non-positive impression to the package C.

The adhesive sheets E also perform the function of stabilizing the folded and overlapping F2 flaps. As mentioned above, these flaps may not be thermally sealed, but fixed only by the effect of the adhesive with which each adhesive sheet E is supplied. In this way a more regular packaging is obtained, since the formation of wrinkles due to the effect is avoided. of the welding unit 1A. It also saves the energy required for welding.

If, on the other hand, the folded and overlapping flaps F2 are thermally sealed with the sealing unit 1A, the adhesive sheets E still have the function of improving the aesthetic appearance of the package C, of masking any imperfections such as holes and of preserving the sealed flaps. from possible damage, made more probable by the presence of wrinkles generated by the temperature on the wrapping sheet F1.

The presence of the adhesive sheets E on one and preferably on both substantially flat and opposite faces of the package C allows the latter to be equipped with writings, decorations, marks or other on all faces, even where the welding between folded and overlapping edges F2 prevents printing of the wrapping sheet F1.

In the embodiment of Figs.3A-3H the dimension H of the wrapping sheet is such that the folded flaps on the two flat faces of the package C overlap. This is particularly suitable in the case in which the wrapping sheet is closed by sealing, before applying the two adhesive sheets E on the two opposite substantially flat faces of the package. In other embodiments, the wrapping sheet F1 may have a smaller dimension H than that illustrated in Figs. 3A-3H. In this case the two substantially flat and opposite faces are not completely covered by the wrapping sheet, but have a free area. An embodiment of this type is shown in Fig. 4. Z indicates a central area of the substantially flat face visible in Fig.4, not covered by the wrapping sheet F1. To complete the package C, the two adhesive sheets E are applied, which can advantageously have a perimeter surface provided with glue and a central surface without glue. In Fig. 4, C1 indicates a perimeter zone, practically forming a frame, where the glue is applied and which surrounds a zone C2 without glue. When the adhesive sheet E is applied on the substantially flat face of the package C, the glued area C1 adheres to the wrapping sheet, along the perimeter area of the substantially flat face, while the area C2 without glue remains in contact with the rolls R in the area Z not covered by wrapping sheet F1.

In this embodiment it is usually envisaged not to seal the wrapping sheet, since there is not sufficient overlapping surface of the edges.

The use of a sheet of wrapping F1 of smaller size H than the usual size (Figs. 3A-3H), allows a substantial saving of consumable material.

In some embodiments, the adhesive sheets E can be made to form a grip handle. Figs. 5A-5F show axonometric views of packages C in which one of the adhesive sheets E form or anchor a handle indicated with M in all embodiments.

In some embodiments, the adhesive sheet E is folded so as to form one or two areas glued to the package, from which protrudes a portion of sheet, detached from the package C, which forms the handle. This portion of the sheet can have one or more openings that form a handle. In other embodiments, the handle M is formed by a band, for example in plastic film, the ends of which are locked between the adhesive sheet E and the corresponding substantially flat face of the package C. In still other embodiments the handle is made by an incision in the adhesive sheet E. In this case the incision can be formed in a central area of the adhesive sheet E without glue, between two glued side bands.

In Fig 5A the adhesive sheet E has two approximately parallel cuts, which define a handle M formed by the same material as the adhesive sheet E. In the area of the handle M the adhesive sheet E can be glue-free. In Fig.5B the adhesive sheet has a portion applied adhesively to the substantially flat face of the package C and a portion without glue in which openings are formed defining a handle. Also in this case the handle is formed by the same adhesive sheet E. In Fig.5C the handle M can be made from a punched sheet, to form the openings defining the handle, which can be glued by means of the adhesive sheet E to the package C In Fig.5D the adhesive sheet E has a central part that is folded and protrudes from the package, possibly without glue, with which the grip handle with grip holes is formed. In variant embodiments, the handle M can be formed by a folded sheet with two flaps that are inserted between the wrapping sheet of the package C and a double adhesive sheet E. In Fig. 5E the handle M is formed by a strip of material , the ends of which are folded under the adhesive sheet E, between this and the substantially flat face of the package C. In Fig. 5F the adhesive sheet E has a central area, rectangular in the example illustrated, without glue, or with an adhesive less adhesive than that applied in the area surrounding the central area. The latter can be pre-engraved along a part of its perimeter: in the example shown, the central area is rectangular and is pre-engraved along three sides. One of the long sides of the perimeter of the central area is intact. In this way the central area of the adhesive sheet E can be detached along three sides and remain adherent to the perimeter area of the adhesive sheet along one of the long sides of the central rectangular area. The flap of adhesive sheet E delimited by the central area can be raised, as shown in the drawing, and form a handle. The handle can be formed by an incision or a cut, for example curved, in the raised central portion.

In general, the handle M can be made of the same material that forms the adhesive sheet E. For example, both the handle and the adhesive sheet can be made of paper or plastic. When the handle is formed by an element applied through the adhesive sheet E but not forming an integral part of it, as in Fig. 5E, the adhesive sheet E and the handle can be made of different materials, for example the adhesive sheet E in paper and the plastic handle M, or vice versa.

In general, the adhesive sheet E can have areas glued with different glues, more or less adhesive, to allow repeated opening and closing of the package C and / or repeated lifting and lowering of the handle formed by the adhesive sheet E.

Claims (22)

Method and machine for wrapping paper rolls, and packaging obtained CLAIMS 1. A package of tissue paper rolls, comprising: - a geometrically ordered group of one or more rolls; - a sheet of wrapping that wraps laterally the geometrically ordered group of one or more rolls and forms folded flaps on two substantially flat and opposite sides of the package characterized in that an adhesive sheet is applied to said folded edges of at least one of the two substantially flat and opposite faces. 2. Packaging according to claim 1, in which respective adhesive sheets are applied on both said substantially flat and opposite faces. Packaging according to claim 1 or 2, wherein the adhesive sheet has a surface covering at least 50%, preferably at least 70%, more preferably at least 80% of the surface of the respective substantially flat face. 4. Packaging according to claim 1 or 2 or 3, in which the folded edges of the wrapping sheet are stabilized in the closed position by the respective adhesive sheet. 5. Packaging according to one or more of the preceding claims, in which the wrapping sheet is made of polymeric material. 6. Packaging according to one or more of the preceding claims, in which the folded flaps are welded together. 7. Packaging according to one or more of the preceding claims, in which the folded flaps are superimposed on each other and completely cover the respective substantially flat face. Packaging according to one or more of claims 1 to 6, wherein the folded flaps leave an area without wrapping sheet on the respective substantially flat face, said area without wrapping sheet being covered by the wrapping sheet. 9. Packaging according to claim 8, in which the adhesive sheet has a perimeter area equipped with glue and a central area without glue. Package according to one or more of the preceding claims, in which the package comprises a grip handle. 11. Packaging according to claim 10, in which the handle is formed by the adhesive sheet. Package according to claim 10, in which the handle is anchored to the package by means of the adhesive sheet. 13. A method of producing a roll package comprising the steps of: - forming a geometrically ordered group of one or more rolls; - wrapping a sheet of wrapping around the geometrically ordered group of rolls and folding flaps of said wrapping sheet onto two substantially flat and opposite faces defined by the geometrically ordered group of rolls; characterized in that it further comprises the step of applying an adhesive sheet to at least one of the substantially flat and opposite faces. 14. Method according to claim 13, in which the step of applying said adhesive sheet comprises the step of applying a respective adhesive sheet on both substantially flat and opposite faces. Method according to claim 13 or 14, wherein the adhesive sheet has a surface covering at least 30%, preferably at least 50%, more preferably at least 70% of the surface of the respective substantially flat face. 16. Method according to one or more of claims 13 to 15, in which the folded flaps are joined together and stabilized by means of the respective adhesive sheet. 17. Method according to one or more of claims 13 to 16, further comprising the step of sealing the folded flaps together before applying the respective adhesive sheet on them. 18. Method according to one or more of claims 13 to 17, comprising a step of forming a handle to the package. Method according to claim 18, wherein the step of forming a handle to the package comprises the step of attaching a handle to the package by means of said adhesive sheet. Method according to claim 18, wherein the step of forming a handle to the package comprises the step of shaping the adhesive sheet so as to form said handle. 21. A machine for the production of packs of rolls comprising: - a wrapping station, configured and arranged to wrap a geometrically ordered group of rolls in a wrapping sheet, forming folded flaps of said wrapping sheet on two substantially flat and opposite faces of said geometrically ordered group of rolls; - along a path of advancement of the geometrically ordered groups of rolls, downstream of the winding station with respect to a direction of advancement of the geometrically ordered groups of rolls along the advancement path, a station for applying adhesive sheets on at least one of said two substantially flat and opposite faces. 22. Machine according to claim 21, in which a welding station is arranged between the wrapping station and the station for applying the adhesive sheets, configured and controlled to seal the folded edges of the wrapping sheet together.