A wrapping method and a wrapping unit to produce, together, two sealed wraps containing two corresponding groups of smoking articles

Abstract

A wrapping method and unit (B) to produce, together, two sealed wraps (3) containing two corresponding groups (5) of smoking articles. It is provided to: feed a double-width initial wrapping sheet (17) made by two final wrapping sheets (8) arranged side by side and connected to one another by a pre-weakened separation line (18); fold the initial wrapping sheet (17) in a tube-like manner around the two corresponding groups (5) of smoking articles by joining two opposite ends of the initial wrapping sheet (17) by means of a transverse seal (T); and separate the initial wrapping sheet (17) already folded in a tube-like manner around the two corresponding groups (5) of smoking articles into two halves, namely, into the two final wrapping sheets (8), by applying a force that causes a tear along the pre-weakened separation line (18). The separation line (18) has two joining points (36) that are arranged in the area of the two opposite ends of the initial wrapping sheet (17) so as to be located inside the transverse seal (T).

Description

[0001] "A WRAPPING METHOD AND A WRAPPING UNIT TO PRODUCE, TOGETHER, TWO SEALED WRAPS CONTAINING TWO CORRESPONDING GROUPS OF SMOKING ARTICLES"

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This Patent Application claims priority from Italian Patent Application No. 102023000027927 filed on December 22, 2023, the entire disclosure of which is incorporated herein by reference.

[0004] TECHNICAL FIELD

[0005] The present invention relates to a wrapping method and to a wrapping unit to produce, together, two sealed wraps containing two corresponding groups of smoking articles.

[0006] The present invention finds advantageous application in the making of a rigid pack of cigarettes with a hinged lid of the "twin" type (namely, containing two sealed wraps arranged side by side to one another) , to which the following disclosure will make explicit reference without thereby losing its generality.

[0007] PRIOR ART

[0008] Rigid pack of cigarettes with a hinged lid are the most popular pack of cigarettes currently on the market as they are simple to make, easy and practical to use, and offer good protection for the cigarettes contained therein.

[0009] A rigid pack of cigarettes with a hinged lid comprises a wrap formed by a group of cigarettes wrapped in a wrapping sheet and a rigid outer casing that houses the wrap on the inside thereof. The outer casing is formed by a cup-shaped container, which houses the wrap and has an open upper end, and a lid, which is also cup-shaped and is hinged to the container to rotate, relative to the container, between an open position and a closed position of the open end. In a traditional pack of cigarettes, the group of cigarettes is wrapped in a rectangular wrapping sheet of metallized paper without glue. To preserve the integrity of the tobacco in the cigarettes, it has been proposed to create a sealed (waterproof) wrap formed by a wrapping sheet of waterproof and heat-sealable material provided with an extraction opening for the cigarettes, which is closed by a reusable sealing label.

[0010] A pack of cigarettes commercially known as "twin" has been known for several years, comprising a rigid outer container that houses two groups of cigarettes (namely, "twins" from which the commercial name of the pack of cigarettes originates) , which are arranged side by side to one another and are wrapped in corresponding wrapping sheets; some examples of a "twin" pack of cigarettes are provided by patent applications WO2023180862A1, WO2019193531A1, EP4051595A1 and EP3283397A1.

[0011] Patent US4258528A, patent EP3362365B1 and patent application WO2021084477A1 describe a packing machine that produces a rigid pack of cigarettes with a hinged lid of the "twin" type and containing two sealed and side-by-side wraps.

[0012] For example, as described in patent applications EP0309818A2 and EP0787651A1, the wrapping machine comprises one single unwinding station supporting one single reel from which one single strip of double-width wrapping material is unwound. Downstream of the unwinding station a longitudinal cutting station is provided where the strip of double-width wrapping material is divided into two separate and distinct strips of wrapping material; two transverse cutting stations are also provided where each strip of wrapping material is cut transversely to separate one single wrapping sheet from the strip of wrapping material. However, this embodiment is still relatively expensive and bulky (as it requires the presence of two independent paths for two separate and distinct strips of wrapping materials) . Patent application EP3653518A1 describes a feeding unit for two wrapping sheets in a packing machine , wherein a pre-weakened separation l ine is obtained in an initial double-width wrapping sheet , which subsequently allows the initial double-width wrapping sheet to be divided in two so as to obtain two f inal single-width wrapping sheets by applying a force that causes a tear along the pre-weakened separation l ine . However, it has been observed that when heat-sealable wrapping material (namely, provided with a plastic layer ) i s used, the tear along the preweakened separation line triggers with a non-negl igible frequency unwanted and random breaks of the wrapping sheets outside the pre-weakened separation line , especially when operating at a high production speed (measured as pack of cigarettes produced per unit of time ) ; in other words , the tearing o f the heat-sealable wrapping material can quite frequently occur in an irregular manner, that i s , developing along tear directions that are not aligned and not paral lel to the pre-weakened separation l ine .

[0013] DESCRI PTION OF THE INVENT ION

[0014] The obj ect o f the present invent ion i s to provide a wrapping method and a wrapping unit to produce , together , two sealed wraps containing two corresponding groups of smoking articles , which wrapping unit and wrapping method are simple to produce and allow to avoid unwanted breakages of the wrapping sheets even when operating at a high production speed (measured as pack of cigarettes produced in the unit of time ) .

[0015] A further obj ect of the present invention is to provide a pack of smoking articl es containing two sealed and s ide-by-s ide wraps that can be made in a wrapping unit that i s simple to make and can operate at a high production speed (measured as packs of cigarettes produced in the unit o f time ) avoiding unwanted breakages o f the wrapping sheets .

[0016] According to the present invention, a wrapping method and a wrapping unit are provided to produce together two sealed wraps containing two corresponding groups of smoking articles, as claimed in the attached claims.

[0017] Furthermore, according to the present invention, a pack of smoking articles is provided containing two sealed and side-by- side wraps, as claimed in the attached claims.

[0018] The claims describe embodiments of the present invention forming an integral part of the present description.

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting embodiment thereof, wherein:

[0021] • Figure 1 is a front perspective view and in a closed configuration of a rigid pack of cigarettes of the "twin" type, namely, containing two sealed side-by-side wraps;

[0022] • Figure 2 is a rear perspective view of the pack of cigarettes of Figure 1 in a closed configuration;

[0023] • Figure 3 is a front perspective view of the pack of cigarettes of Figure 1 in an open configuration;

[0024] • Figure 4 is a front perspective view of one single sealed wrap contained in the pack of cigarettes of Figure 1;

[0025] • Figure 5 is a schematic and cross-sectional view of the sealed wrap of Figure 4;

[0026] • Figure 6 is a plan view without folds of a wrapping sheet used to make the sealed wrap of Figure 4;

[0027] • Figure 7 is a perspective and schematic view showing the paths followed by the components of the sealed wrap of Figure 4 in a wrapping unit that is made according to the present invention;

[0028] • Figure 8 is a front view, with parts removed for clarity, of three wrapping wheels of the wrapping unit of Figure 7;

[0029] • Figure 9 is a perspective view, with parts removed for clarity, of two wrapping wheels and a linear wrapping conveyor of the wrapping unit of Figure 7; • Figure 10 is a schematic view of a feeding device of the wrapping unit of Figure 7; and

[0030] • Figure 11 is a plan view of an initial wrapping sheet that is centrally provided with a pre-weakened separation line that separates the initial wrapping sheet into two final wrapping sheets .

[0031] PREFERRED EMBODIMENTS OF THE INVENTION

[0032] In Figures 1, 2 and 3, number 1 denotes as a whole a rigid "twin" pack of cigarettes. The pack of cigarettes 1 comprises a container 2 made of rigid cardboard or paperboard and cup-shaped and a pair of wraps 3 (one of which is better illustrated in Figure 4) housed side-by-side inside the container 2.

[0033] The container 2 has an open upper end and is provided with a lid 4, which is cup-shaped and is hinged to the container 2 along a hinge (illustrated in Figure 2) to rotate, relative to the container 2, between an open position (illustrated in Figure 3) and a closed position (illustrated in Figures 1 and 2) of the open upper end.

[0034] Each sealed wrap 3 (illustrated in Figure 4) contains a group 5 of cigarettes (schematically illustrated in Figure 5) having a parallelepiped shape.

[0035] As illustrated in Figure 4, the sealed wrap 3 has an extraction opening 6 on the top and in front, which is delimited by a preweakened tearable line, is closed by a reusable closing label 7 and comprises a portion of a front wall of the sealed wrap 3 and a portion of an upper wall of the sealed wrap 3. According to a different embodiment not illustrated, the sealed wrap 3 is without of the extraction opening 6 and the respective closing label 7 and has a removable upper portion, which is separated from the rest of the sealed wrap 3 by a pre-weakened tearable line to be removed by tearing when the sealed wrap 3 is opened for the first time; in this embodiment, the sealed wrap 3 is preferably provided with a tear-off band to facilitate tearing of the sealed wrap 3 along the pre-weakened line.

[0036] The sealed wrap 3 is obtained by folding a final wrapping sheet 8 (illustrated in Figure 6) , which has a rectangular shape, comprises at least one layer of air-impermeable and heat- sealable plastic material, and is folded directly around the group 5 of cigarettes so as to be in direct contact with the cigarettes (or with at least a part of the cigarettes) . Once the final wrapping sheet 8 has been folded around the group 5 of cigarettes to form the sealed wrap 3, the shape of the sealed wrap 3 is stabilized by carrying out a sealing of the overlapping portions of the final wrapping sheet 8.

[0037] As illustrated in Figure 5, the sealed wrap 4 comprises a reinforcing element 9, which is made of cardboard or rigid paperboard, is "U"-shaped, is arranged inside the sealed wrap 3 in contact with the group 5 of cigarettes and comprises a front wall 10 and two lateral walls 11 arranged on opposite sides of the front wall 10.

[0038] The formation of the sealed wrap 3 comprises initially forming the group 5 of cigarettes and then folding the reinforcing element 9 around the group 5 of cigarettes. Subsequently and as partially illustrated in Figure 7, the final wrapping sheet 8 is folded around the group 5 of cigarettes coupled to the reinforcing element 9.

[0039] The final wrapping sheet 8 is folded (in a known manner) around the group 5 of cigarettes to form a tubular wrap that has two open lateral edges and is stabilized by means of a transverse seal T (illustrated in Figure 7) ; in particular, the tubular wrap is formed by forming a transverse sealing fin in the final wrapping sheet 8 (folded around the group 5 of cigarettes) in the area of the rear or lower wall and at the end of the sealing the transverse sealing fin is folded by 90° against the rear or lower wall. Subsequently, and as illustrated in Figure 7, the two open lateral edges of the final wrapping sheet 8 (which has a tubular shape around the group 5 of cigarettes) are closed by means of the so-called "soap-bar fold" which for each lateral edge comprises: folding two smaller flaps 12 and 13 against the smaller lateral wall of the group 5 of cigarettes, folding a larger flap 14 against the smaller lateral wall of the group 5 of cigarettes and over the two smaller flaps 12 and 13 folded previously, and finally folding the other larger flap 15 against the smaller lateral wall of the group 5 of cigarettes and over the two smaller flaps 12 and 13 and the larger flap 14 folded previously. After completing the folding of the final wrapping sheet 8 around the group of cigarettes 5 by closing the two lateral edges with respective lateral folds, these lateral folds are stabilized by means of a longitudinal seal, namely, by heatsealing the overlapping parts of the final wrapping sheet 8 in the area of the smaller lateral walls of the group of cigarettes 5.

[0040] A packing machine that is designed to produce the above described pack 1 of cigarettes generally operates with intermittent motion (namely, a motion that involves a cyclic alternation of motion steps and stop steps) and comprises a forming unit where the groups 5 of cigarettes are formed in succession, a wrapping unit B (schematically illustrated in Figure 7) where a respective final wrapping sheet 8 is wrapped around each group 5 of cigarettes to make a sealed wrap 3, and a wrapping unit where a blank is wrapped around each pair of sealed wrap 3 coupled to one another (namely, arranged side by side) to make a container 2 provided with a lid 4.

[0041] As illustrated in Figure 7, the wrapping unit B (which produces together two sealed wrap 3 containing two corresponding groups 5 of cigarettes) comprises wrapping conveyors (better illustrated in Figures 8 and 9) that are designed to advance the two side-by-side groups 5 of cigarettes along a wrapping path (partly circular, partly straight) . In particular, each wrapping conveyor supports a plurality of pairs of side-by-side pockets, each of which is shaped to receive and house a corresponding group 5 of cigarettes; in this way, at each advancement step each wrapping conveyor advances two side-by-side pockets (transversely, namely, perpendicularly to the wrapping path) and therefore two side-by-side groups 5 of cigarettes contained in the respective side-by-side pockets.

[0042] The wrapping conveyors of the wrapping unit B receive from a forming conveyor of the forming unit the pairs of groups 5 of cigarettes already coupled to the respective reinforcing elements 9 and are configured to advance the pairs of side-by- side groups 5 of cigarettes together with the corresponding reinforcing elements 9 and together with the corresponding final wrapping sheets 8 along the wrapping path to fold each final wrapping sheet 8 around the corresponding group 5 of cigarettes.

[0043] In particular, the wrapping path passes through a coupling station SI where each pair of side-by-side groups 5 of cigarettes is coupled with a corresponding pair of final wrapping sheets 8; in the coupling station SI a feeding device 16 (illustrated in Figures 8 and 10) is provided, which is configured to simultaneously feed two final wrapping sheets 8 so that each final wrapping sheet 8 is coupled to a respective group 5 of cigarettes already previously coupled to a reinforcing element 9. In particular, the feeding device 16 feeds initial wrapping sheets 17 (better illustrated in Figure 11) into the coupling station SI, each of which has a width double with respect to the width of the final wrapping sheets 8; that is, the width of the initial wrapping sheet 17 is equal to the width of two final side-by-side wrapping sheets 8. Furthermore, each initial wrapping sheet 17 has a centrally pre-weakened separation line 18 which divides the initial wrapping sheet 17 into two equal halves, each corresponding to a final wrapping sheet 8; in other words, each initial wrapping sheet 17 is formed by two final side-by-side wrapping sheets 8 and separated (or connected, depending on the point of view) from one another by the preweakened separation line 18.

[0044] The wrapping unit B comprises a series of folding devices that are configured to fold each final wrapping sheet 8 around a respective group 5 of cigarettes coupled to a reinforcing element 9 to form (and stabilize by sealing) a respective sealed wrap 3.

[0045] In the coupling station SI, the final wrapping sheet 17 (formed by two final side-by-side wrapping sheets 8) is advanced along a feeding path perpendicular to, and intersecting with, a advancement path of the two groups 5 of cigarettes; in this way, the final wrapping sheet 17 is fed in front of the two groups 5 of cigarettes so that the two groups 5 of cigarettes in advancement intercept the final wrapping sheet 17 and determine the progressive "U" folding of the final wrapping sheet 17. Subsequently, the final wrapping sheet 17 (formed by two final side-by-side wrapping sheets 8) is folded in a tube-like manner around two corresponding groups 5 of cigarettes and the tubular wrap (with two open lateral ends) thus formed is stabilized by means of a transverse seal T.

[0046] The wrapping unit B comprises a dividing device 19 (schematically illustrated in Figure 7 according to two possible conf igurations / positions ) which is able to divide the initial wrapping sheet 17 in two by applying a traction (force) which causes a tear along the pre-weakened separation line 18; in other words, the dividing device 19 applies a traction (force) to the initial wrapping sheet 17 (folded in a tube-like manner around two groups 5 of cigarettes) to tear the initial wrapping sheet 17 along the pre-weakened separation line 18 and therefore obtain two final wrapping sheets 8 (each of which is folded in a tube-like manner around a corresponding group 5 of cigarettes) . In particular, the dividing device 19 applies a traction (force) to the initial wrapping sheet 17 that causes a tear along the pre-weakened separation line 18 and therefore allows one final wrapping sheet 8 to be separated from the other final wrapping sheet 8. In other words, the dividing device 19 can be a diverter that separates the two groups 5 of cigarettes partially wrapped in the respective final wrapping sheets 8 from one another, causing a consequent tearing of the initial wrapping sheet 17 along the pre-weakened separation line 18.

[0047] The dividing device 19 generates a tear along the pre-weakened separation line 18 of each initial wrapping sheet 17 by applying to the two halves of the initial wrapping sheet 17 (namely, to the two final wrapping sheets 8 that make up the initial wrapping sheet 17 and are divided / connected to one another by the preweakened separation line 18) a traction (force) in opposite directions; this traction (force) in opposite directions can be directed transversely (namely, perpendicular to the pre-weakened separation line 18) , can be directed longitudinally (namely, parallel to the pre-weakened separation line 18) , or can be directed obliquely (namely, with both a transverse component and a longitudinal component) . In the embodiments illustrated in Figure 7, the traction (force) in opposite directions lies in a horizontal plane; alternatively, the traction (force) could lie in a vertical plane or in an inclined plane (namely, neither perfectly horizontal nor perfectly vertical) .

[0048] More generally, the dividing device 19 can comprise a countering element configured to cause a tear along the pre-weakened separation line 18. The aforementioned countering element can be fixed. Alternatively, the aforementioned countering element can be movable.

[0049] According to a possible embodiment, therefore, the traction (force) that separates the two final wrapping sheets 8 from the initial wrapping sheet 17 (namely, the traction that causes the tear along the pre-weakened separation line 18) could also be (at least partially) caused by a countering element (fixed or movable) against which the initial wrapping sheet 17 impacts during its advancement; in particular, the segment of the separation line 18 of the initial wrapping sheet 17 impacts against the countering element during the advancement of the initial wrapping sheet 17. In other words, the dividing device 19 could comprise a countering element (fixed or movable) against which the initial wrapping sheet 17 impacts during its advancement. The countering element forms a division (a tear) by breaking the initial wrapping sheet 17 along the separation line 18.

[0050] The dividing device 19 divides each initial wrapping sheet 17 into two when the initial wrapping sheet 17 has been folded in a tube-like manner around two groups 5 of cigarettes and after the transverse seal T of the initial wrapping sheet 17 has been completed .

[0051] Finally, each tubular wrap is closed laterally by means of lateral folds which are subsequently stabilized by means of two longitudinal sealings thus completing (ending) the forming of the sealed wrap 3. In particular, for each final wrapping sheet 8, the two smaller flaps 12 and 13 are initially folded against a smaller side wall of the group 5 of cigarettes, subsequently a larger flap 14 is folded against a smaller side wall of the group 5 of cigarettes over the two smaller flaps 12 and 13 folded previously, and finally the other larger flap 15 is folded against a smaller side wall of the group 5 of cigarettes over the two smaller flaps 12 and 13 and the larger flap 14 folded previously .

[0052] According to a possible embodiment, when the initial wrapping sheet 17 is still intact (and folded in a tube-like manner around the two groups 5 of cigarettes) , namely, before completely separating the two final wrapping sheets 8 by tearing along the separation line 18, all eight smaller flaps 12 and 13 (namely, the front and rear edges of the tubular wrap) are folded by 90° and against the respective groups 5 of cigarettes. Once the smaller flaps 12 and 13 have been folded, the initial wrapping sheet 17 is torn along the separation line 18 (with one of the methods described above) to divide and therefore separate the two final wrapping sheets 8 (namely, the two inner wraps 3) and the folding of the final wrapping sheets 8 (namely, the two inner wraps 3) is completed by folding one over the other and over the previously folded smaller flaps 12 and 13 the larger flaps 14 and 15 of each open lateral end of the tubular wrap.

[0053] As illustrated in Figure 8, the wrapping unit B comprises a wrapping wheel 20 (vertically arranged) which is arranged immediately downstream of the forming conveyor, is mounted so as to rotate around a horizontal rotation axis 21 and supports a plurality of pairs of pockets adapted to contain two groups 5 of cigarettes coupled to an initial wrapping sheet 17. The wrapping wheel 20, by rotating around the rotation axis 21, advances each pair of side-by-side pockets between a feeding station where the pair of side-by-side pockets receives a pair of side-by-side groups 5 of cigarettes, through a feeding station S2 where the pair of side-by-side pockets receives an initial wrapping sheet 17 (formed by a pair of final side-by- side wrapping sheets 8) which is placed outside the pair of side-by-side pockets, and the coupling station SI in which the pair of side-by-side pockets delivers the pair of side-by-side groups 5 of cigarettes coupled to the initial wrapping sheet 17.

[0054] The wrapping unit B comprises a wrapping wheel 22 (vertically arranged) which is arranged immediately downstream of the wrapping wheel 20, is mounted so as to rotate around a horizontal rotation axis 23, and supports a plurality of pairs of pockets adapted to contain a pair of side-by-side groups 5 of cigarettes coupled to the respective initial wrapping sheet 17. The wrapping wheel 22, by rotating around the rotation axis 23, moves each pair of side-by-side pockets between the coupling station SI, in which the pair of side-by-side pockets receives a pair of side-by-side groups 5 of cigarettes and coupled to the initial wrapping sheet 17 from the wrapping wheel 20 and a transfer station S3, in which the pair of side-by-side pockets releases the pair of side-by-side groups 5 of cigarettes coupled to the initial wrapping sheet 17 folded in a tube-like manner.

[0055] The packing machine 33 comprises a folding device 24 which is coupled to the wrapping wheel 22 and is configured to fold in a tube-like manner an initial wrapping sheet 17 around the corresponding pair of groups 5 of cigarettes. Each initial wrapping sheet 17 folds into a "U" shape around the corresponding pair of groups 5 of cigarettes when the corresponding pair of groups 5 of cigarettes enters (together with the initial wrapping sheet 17) into the respective pocket in the coupling station SI; the folding device 24 performs the folding in a tube-like manner of each initial wrapping sheet 17 around the corresponding pair of groups 5 of cigarettes.

[0056] A sealing device 25 is provided which is coupled to the wrapping wheel 22 and is configured to perform the transverse seal T on an initial wrapping sheet 17 folded in a tube-like manner around the corresponding pair of groups 5 of cigarettes. According to a preferred embodiment, the sealing device 25 comprises three different sealing heads 26 arranged in succession around the wrapping wheel 22 so that the transverse seal T on each final wrapping sheet 17 folded in a tube-like manner is performed in three distinct and successive steps.

[0057] As illustrated in Figure 9, the wrapping unit B comprises a wrapping conveyor 27 provided with folding devices 28 configured to fold a final wrapping sheet 8 around the corresponding group 5 of cigarettes thus completing the formation of the sealed wrap 3, namely, by closing the two open ends of the final wrapping sheet 8 folded in a tube-like manner as illustrated in Figure 7. The wrapping unit B also comprises sealing devices that are coupled to the wrapping conveyor 27 and are configured to perform longitudinal seals on a final wrapping sheet 8 folded around the group 5 of cigarettes thus completing the formation of the corresponding sealed wrap 3.

[0058] As illustrated in Figure 9, the wrapping unit B comprises a wrapping wheel 29 (arranged horizontally) which is interposed between the wrapping wheel 22 and the wrapping conveyor 27, is mounted so as to rotate around a vertical rotation axis 30, and supports four pockets, each designed to contain two side-by- side groups 5 of cigarettes wrapped in a final wrapping sheet 17 having a tubular shape.

[0059] As illustrated in Figure 10, the feeding device 16 is adapted to feed at the feeding station SI and at each cycle an initial wrapping sheet 17 formed by two final wrapping sheets 8 still joined together along the separation line 18.

[0060] The feeding device 16 comprises an unwinding station S4 in which a strip 32 of wrapping material having a width double that of the final wrapping sheets 8 is unwound from a reel 31; namely, the width of the strip 32 of wrapping material is equal to the width of two final side-by side wrapping sheets 8 and therefore is equal to the width of a final wrapping sheet 17.

[0061] The feeding device 16 comprises a feeding line 33 that feeds the strip 32 of wrapping material from the reel 31 (from which the strip 32 of wrapping material is unwound) to the wrapping unit B; the feeding line 33 is formed by idle return drums (known and partly illustrated) and pairs of motorized rollers (between which the strip 32 of wrapping material is "pulled" and also known and not illustrated) .

[0062] A weakening station S5 is arranged along the feeding line 33, where a weakening device 34 is provided, which forms the preweakened separation line 18 on the centreline of the strip 32 of wrapping material.

[0063] Furthermore, along the feeding line 33 a separation station S6 is arranged, in which a cutting device 35 is provided, which cyclically performs a transverse cut of the strip 32 of wrapping material to separate a series of initial wrapping sheets 17 from the strip 32 of wrapping material. Each initial wrapping sheet 17 (just like the strip 32 of wrapping material) has a width double that of the width of the final wrapping sheets 8; namely, the width of the initial wrapping sheet 17 is equal to the width of two final side-by-side wrapping sheets 8 (as better illustrated in Figure 11) . Furthermore, each initial wrapping sheet 17 (just like the strip 32 of wrapping material) has at the centre the pre-weakened separation line 18 (formed by the weakening device 34) which divides the initial wrapping sheet 17 into two equal halves, each of which corresponds to a final wrapping sheet 8; in other words, each initial wrapping sheet 17 is formed by two final side-by-side wrapping sheets 8 and separated from one another by the pre-weakened separation line

[0064] 18 (as better illustrated in Figure 7) .

[0065] The feeding line 33 ends in the feeding station S2, where each initial wrapping sheet 17 is fed to the wrapping wheel 20.

[0066] As illustrated in Figure 11, in each initial wrapping sheet 17 the separation line 18 has two (and exactly two) joining points 36 (namely, portions that are not separated or not completely separated) which are located at the two opposite ends of the initial wrapping sheet 17 (namely, at the head and tail of the initial wrapping sheet 17) so as to be located inside the transverse seal T. In other words, the two joining points 36 are arranged in the areas of the initial wrapping sheet 17 that overlap one another so as to form the transverse seal T. In this way, the segment where the two joining points 36 of the separation line 18 are arranged is more robust (having double the thickness due to the transverse seal T) and is therefore less subject to unwanted and uncontrolled breakages (namely, irregular tears that develop along breakage directions that are not aligned with the separation line 18) when the initial wrapping sheet 17 is separated into two halves (namely, into two final wrapping sheets 8) due to traction (as explained above) .

[0067] Furthermore, the transverse seal T is located in an area of the sealed wrap 3 that is not visible in the pack of cigarettes 1 and therefore even if irregular tears were to occur at the two joining points 36 of the separation line 18, these irregular tears would still not be visible in the pack of cigarettes 1 (as they are hidden inside the container 2) .

[0068] The presence of the two joining points 36 of the separation line 18 is important for the correct making of the transverse seal T, as it guarantees a clear separation between the transverse seal T of a final wrapping sheet 8 and the transverse seal T of the other final wrapping sheet 8 (namely, it guarantees that part of a transverse seal T of a final wrapping sheet 8 does not "invade" the area of the transverse seal T of the other final wrapping sheet 8) . In other words, it is important that the two joining points 36 of the separation line 18 (namely, breakable connections between the right side of the initial wrapping sheet 17 making a final wrapping sheet 8 and the left side of the initial wrapping sheet 17 making the other final wrapping sheet 8) forming the transverse seal T are provided in the end portions of the initial wrapping sheet 17 because these connections (namely, the joining points 36) prevent the two final wrapping sheets 8 from overlapping in the area of the two transverse seals T and therefore prevent the two transverse seals T from merging into one single transverse seal T which joins the two final side-by-side wrapping sheets 8 in a way that is difficult to separate (especially without causing significant damage to the wrapping material) .

[0069] During the side-by-side advancement of the two final wrapping sheets 8, if the two final wrapping sheets 8 were completely free from one another (namely, without any residual joining point along the separation line 18) a partial overlap could occur between the edges of the two final wrapping sheets 8 as one final wrapping sheet 8 could deviate laterally thus "invading" the area of the other final wrapping sheet 8 and this "invasion" could overlap the two transverse seals T (even just one millimetre of overlap is enough) creating an unwanted very strong union between the two final wrapping sheets 8 that causes significant damage to the wrapping material when the two final wrapping sheets 8 are separated.

[0070] In other words, the separation line 18 comprises a central segment with a higher degree of weakening and two lateral segments (namely, in the area of the two opposite ends of the initial wrapping sheet 17) which form the two joining points 36 and where it has a lower degree of weakening (if not even zero) . Preferably, in the central segment the separation line 18 has one single continuous through cut (namely, without interruption) of the wrapping material while in the two lateral areas which make the two joining points 36 the separation line 18 has a weakening (more or less marked) of the wrapping material. That is, the separation line 18 comprises one single continuous through cut (namely, without interruption) that is located at the centre of the initial wrapping sheet 17 and has at the two opposite ends (namely, in the area of the two opposite ends of the initial wrapping sheet 17) the two joining points 36 where the wrapping material is weakened but still present.

[0071] In the area of the two joining points 36, the pre-weakened separation line 18 can comprise one single non-through incision that is obtained on the wrapping material; alternatively, in the area of the two joining points 36, the pre-weakened separation line 18 can comprise a plurality of through incisions that are obtained through the wrapping material, are aligned with one another and are separate from one another, namely, between a through incision and the subsequent (adjacent) through incision, a segment is provided where the wrapping material is still intact .

[0072] The embodiments described herein can be combined with one another without departing from the scope of protection of the present invention.

[0073] The wrapping unit B described above has numerous advantages.

[0074] First, the wrapping unit B described above allows the production of a pack 1 of cigarettes containing two sealed and side-by- side wraps 3 by operating at a high production speed (measured as packs 1 of cigarettes produced per unit of time) while at the same time ensuring a high final quality of the sealed wraps 3.

[0075] This result is achieved thanks to the fact that the central division of the initial wrapping sheet 17 always and only occurs along the separation line 18 without unwanted tears in the wrapping material outside the separation line 18.

[0076] Furthermore, the wrapping unit B described above is simple to manufacture .

[0077] The embodiments illustrated in the attached figures refer to the making of a pack of cigarettes, but the present invention can be applied without substantial modifications also to the making of any other type of pack of smoking articles (for example a pack of cigars, a pack of electronic cigarettes of the liquid vaporization type, a pack of new generation cigarettes without tobacco combustion, etc. ) .

[0078] LIST OF REFERENCE NUMBERS OF THE FIGURES

[0079] 1 pack of cigarettes

[0080] 2 outer container 3 sealed wrap

[0081] 4 lid

[0082] 5 group of cigarettes

[0083] 6 extraction opening

[0084] 7 closing label

[0085] 8 wrapping sheet

[0086] 9 reinforcement element

[0087] 10 front wall

[0088] 11 lateral walls

[0089] 12 smaller flap

[0090] 13 smaller flap

[0091] 14 larger flap

[0092] 15 larger flap

[0093] 16 feeding device

[0094] 17 initial wrapping sheet

[0095] 18 separation line

[0096] 19 dividing device

[0097] 20 wrapping wheel

[0098] 21 rotation axis

[0099] 22 wrapping wheel

[0100] 23 rotation axis

[0101] 24 folding device

[0102] 25 sealing device

[0103] 26 sealing heads

[0104] 27 wrapping conveyor

[0105] 28 folding devices

[0106] 29 wrapping wheel

[0107] 30 rotation axis

[0108] 31 reel

[0109] 32 strip of wrapping material

[0110] 33 feeding line

[0111] 34 weakening device

[0112] 35 cutting device

[0113] 36 joining points

[0114] B wrapping unit

[0115] SI coupling station feeding station trans fer station unwinding station weakening station separation stationransverse seal

Claims

CLAIMS1) A wrapping method to produce, together, two sealed wraps (3) containing two corresponding groups (5) of smoking articles; the wrapping method comprises the steps of: feeding an initial wrapping sheet (17) with a double width made by two final wrapping sheets (8) arranged side by side and connected to one another by a pre-weakened separation line (18) ; folding the initial wrapping sheet (17) in a tube-like manner around the two corresponding groups (5) of smoking articles by joining two opposite ends of the initial wrapping sheet (17) by means of a transverse seal (T) ; and separating the initial wrapping sheet (17) , already folded in a tube-like manner around the two corresponding groups (5) of smoking articles into two halves, namely, into the two final wrapping sheets (8) , by applying a force that causes a tear along the pre-weakened separation line (18) ; the wrapping method is characterised in that the separation line (18) has two and only two joining points (36) , which are arranged in the area of the two opposite ends of the initial wrapping sheet (17) so as to be located inside the transverse seal (T) .2) The wrapping method according to claim 1, wherein the separation line (18) comprises a central segment, where it has a higher degree of weakening and two side segments, which are located in the area of the two opposite ends of the initial wrapping sheet (17) and make the two joining points (36) , and where the separation line (18) has a lower degree of weakening.3) The wrapping method according to claim 2, wherein the central segment of the separation line (18) has one single continuous through cut .4) The wrapping method according to claim 1, 2 or 3, wherein the separation line (18) comprises one single continuous through cut, which is arranged at the centre of the initial wrappingsheet (17) and has, at the two opposite ends in the area of the two opposite ends of the initial wrapping sheet (17) , the two joining points (36) where the wrapping material is weakened but still present.5) The wrapping method according to one of the claims from 1 to 4, wherein, in the area of the two joining points (36) , the preweakened separation line (18) comprises one single non-through incision that is obtained on the wrapping material.6) The wrapping method according to one of the claims from 1 to 4, wherein, in the area of the two joining points (36) , the preweakened separation line (18) comprises a plurality of through incisions that are made through the wrapping material, are aligned with one another and are separate from one another.7) The wrapping unit (B) to produce, together, two sealed wraps (3) containing two corresponding groups (5) of smoking articles; the wrapping unit (B) comprises: a feeding device (16) , which is configured to feed an initial double-width wrapping sheet (17) made by two final wrapping sheets (8) arranged side by side and connected to one another by a pre-weakened separation line (18) ; at least one folding device, which is configured to fold the initial wrapping sheet (17) in a tube-like manner around the two corresponding groups (5) of smoking articles by joining two opposite ends of the initial wrapping sheet (17) by means of a transverse seal (T) ; and a dividing device (19) configured to separate the initial wrapping sheet (17) , already folded in a tube-like manner around the two corresponding groups (5) of smoking articles into two halves, namely, into the two final wrapping sheets (8) , by applying a force that causes a tear along the pre-weakened separation line (18) ; the wrapping unit (B) is characterized in that the separation line (18) has two and only two joining points (36) , that arearranged at the two opposite ends of the initial wrapping sheet (17) so as to be located inside the transverse seal (T) .8) The wrapping unit (B) according to claim 7, wherein the dividing device (19) comprises a countering element configured to cause a tear along the pre-weakened separation line (18) .9) A pack (1) of smoking articles comprising: a container (2 ) ; two groups of smoking articles (5) ; two sealed wraps (3) , which are housed in the container (2) next to one another and each made by a wrapping sheet (8) , which is folded around the group (5) of smoking articles and has two opposite ends, which are joined together by means of a transverse seal (T) ; the pack (1) for smoking articles is characterised in that each wrapping sheet (8) has two and only two joining points (36) , which were separated by tearing and are arranged in the area of the two opposite ends of the wrapping sheet (8) so as to be located inside the transverse seal (T) .

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