WO2014072953A1

WO2014072953A1 - Cigarette manufacturing assembly machine, and relative assembly method

Info

Publication number: WO2014072953A1
Application number: PCT/IB2013/060015
Authority: WO
Inventors: Ivan Eusepi; Marco Esposti; Massimo Sartoni
Original assignee: G.D Societa' Per Azioni
Priority date: 2012-11-08
Filing date: 2013-11-08
Publication date: 2014-05-15
Also published as: JP6224720B2; EP2916668A1; EP2916668B1; JP2016501014A; WO2014072953A8; US20150282522A1; RU2635797C2; PL2916668T3; CN104768404A; CN104768404B; ITBO20120614A1; RU2015121674A

Abstract

A method and assembly machine (1) for producing multicomponent cigarettes (2), each having a number of portions (3), which have a central axis (X), and of which at least one portion (3) is defined by a filtering element, and at least one portion (3) is defined by an aromatic element; the assembly machine (1)' has a combining unit (CU) for forming groups (4) of portions (3) travelling perpendicularly to their central axis (X); a first wrapping unit (WUi), which receives a succession of groups (4) of portions (3) from the combining unit (CU) and feeds them parallel to their central axis (X); and a second wrapping unit (WU2), which receives a succession of groups (4) of portions (3) from the first wrapping unit (WUi), feeds them perpendicularly to their central axis (X), and winds a sheet of wrapping material (44) about each group (4) of portions (3).

Description

CIGARETTE MANUFACTURING ASSEMBLY MACHINE, AND RELATIVE ASSEMBLY METHOD

TECHNICAL FIELD

The present invention relates to a cigarette manufacturing assembly machine and relative assembly method .

BACKGROUND ART

Demand within the industry has recently extended to the manufacture of multicomponent cigarettes, each of which comprises a number of end-to-end portions, at least one of which is normally defined by a filter element, and at least another of which is defined by an aromatic, preferably tobacco-based, element.

Manufacturing cigarettes of this type calls for an assembly machine adaptable to different portion combinations .

Patent Application US-A1-2006201523, for example, describes a filter-tipped cigarette manufacturing machine, in which the cigarette comprises a tobacco portion, and a combination filter in turn comprising at least three different component parts. The cigarette manufacturing machine comprises a combining unit for forming groups of filter portions, each group comprising three different filter portions aligned axially and contacting end to end; and a unit for forming a continuous tobacco rod, which is cut into double-length portions and fed to a wrapping unit. The wrapping unit receives a succession of groups of double-length filter portions from the combining unit and a succession of double-length tobacco portions, and is designed to form groups, each comprising a tobacco portion, a double- length filter portion, and a tobacco portion, and to wrap them in a sheet of wrapping material to form double-length cigarettes, which are then cut into individual cigarettes.

The manufacturing machine described in US-A1- 2006201523 has several drawbacks, by not allowing for fast, easy brand change (i.e. switching from production of one type of cigarette to another) . To meet changing market demand, on the other hand, a modern manufacturing machine of this type must be capable of producing different types of cigarettes effectively and efficiently .

DESCRIPTION OF THE INVENTION

It is an object of the present invention to provide a cigarette manufacturing assembly machine designed to eliminate the aforementioned drawbacks, and which is cheap and easy to implement.

It is a further object of the present invention to provide a cigarette assembly method designed to eliminate the aforementioned drawbacks, and which is cheap and easy to implement.

According to the present invention, there are provided a cigarette manufacturing assembly machine, and a relative assembly method, as claimed in the accompanying Claims .

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the attached drawings, in which :

Figure 1 shows a schematic front view, with parts removed for clarity, of a first detail of a cigarette manufacturing assembly machine in accordance with the present invention;

Figure 2 shows a schematic front view, with parts removed for clarity, of a second detail of the Figure 1 assembly machine;

Figure 3 shows a schematic front view, with parts removed for clarity, of a third detail of the Figure 1 assembly machine;

Figure 4 shows a schematic plan view of the Figure

1 assembly machine;

Figures 5a to 5m show schematics of the steps in the method of assembling two cigarettes, in accordance with the present invention;

PREFERRED EMBODIMENTS OF THE INVENTION

In Figures 1 to 4, number 1 indicates as a whole an assembly machine for producing multicomponent cigarettes 2. Each cigarette 2 comprises a number of portions 3 with a central axis X, and of which at least one portion 3 is defined by a filter element, and at least one portion 3 is defined an aromatic, preferably tobacco- based, element.

As shown schematically in Figure 4, assembly machine 1 has a U-shaped layout, and comprises a combining unit CU for forming portion groups 4; a transfer unit TUi; a wrapping unit WUi; a transfer unit TU₂; and a wrapping unit WU₂.

Combining unit CU forms portion groups 4, each preferably comprising a number of axially aligned portions 3, and which are fed transversely (i.e. perpendicularly to their central axis X) . Transfer unit TUi is located downstream from combining unit CU, to transfer portion groups 4, travelling transversely, from combining unit CU, and feed them axially (i.e. parallel to central axis X) to wrapping unit WUi.

As described in more detail below, wrapping unit

WUi receives a succession of portion groups 4 from transfer unit TUi, winds a sheet of wrapping material about the succession of portion groups 4 travelling longitudinally (i.e. parallel to central axis X) and, finally, cuts portion groups 4 apart transversely.

Transfer unit TU₂ is located downstream from wrapping unit WUi, to transfer portion groups 4, travelling longitudinally, from wrapping unit WUi, and feed them transversely to wrapping unit WU₂.

Finally, wrapping unit U₂ receives portion groups 4 from transfer unit TU₂, inserts further portions 3 into portion groups 4, winds a further sheet of wrapping material about the succession of portion groups 4 and, finally, cuts portion groups 4 transversely into two cigarettes 2, which are carried off assembly machine 1 by an output conveyor.

More specifically, and as shown more clearly in Figures 1 and 2, combining unit CU comprises a frame 5, which rests on the floor and supports a number of structurally identical feed stations 6, each for supplying respective portions 3 from which to form portion groups 4.

More specifically, combining unit CU comprises three feed stations 6*, 6** and 6***. Each feed station 6 comprises a top hopper 7 containing a mass of respective portions 3; and a pickup drum 8, which withdraws portions 3 successively from the bottom of top hopper 7, and cooperates with a cutting device 9 with blades for cutting portions 3 transversely into portions 3 of desired length. Each feed station 6 also comprises a number of - in particular, three - aligning and transfer drums 10, which receive, align and, if 6

necessary, axially part portions 3 of desired length from pickup drum 8.

Except for the most upstream feed station 6*, each feed station 6 also comprises an insertion or combining drum 11, which receives portions 3 of desired length from a final aligning drum 10, and inserts them into respective portion groups 4 from the adjacent upstream feed station 6.

The first, i.e. most upstream, feed station 6* differs from the ones following it by having, instead of an insertion drum 11, a portion 3 transfer drum, which, for the sake of simplicity, is also indicated by reference number 11, despite it differing structurally from insertion drums 11 described above.

Finally, each feed station 6 comprises an output drum 12, which receives portion groups 4 from relative drum 11, and transfers them to the next feed station 6 or, in the case of the last feed station 6***, to transfer unit TUi .

As shown schematically in Figure 5a, first feed station 6* forms a portion group 4* of two coaxial portions 3A contacting end to end.

Second feed station 6** forms a portion group 4**, in which two portions 3B are positioned coaxial with portion group * from first feed station 6*, each with one end facing and contacting a respective end of portion group 4*. In other words, portion group 4* is interposed between two portions 3B at second feed station 6** (as shown in Figure 5b) .

Finally, third feed station 6*** forms a portion group ***, in which two end-to-end portions 3C are positioned coaxial with portion group 4** from second feed station 6**, with one end facing and contacting one end of portion group 4**. in other words, the two portions 3C are aligned with a portion 3B in group portion 4** (as shown in Figures 5c and 5d) .

In a variation not shown, third feed station 6*** forms a portion group 4***, in which two portions 3C are positioned coaxial with portion group 4** from second feed station 6**, each with one end facing and contacting a respective end of portion group 4**. In other words, portion group 4** is interposed between two portions 3C at third feed station 6***.

In another variation not shown, first feed station 6* forms a portion group 4*, in which two portions 3A are positioned coaxial, with their facing ends spaced axially a given distance apart. Second feed station 6** forms a portion group 4**, in which two coaxial portions 3B, spaced axially a given distance apart, are interposed between the two portions 3A. And finally, third feed station 6*** forms a portion group 4***, in which two coaxial portions 3C contacting end to end are interposed between the two portions 3B.

In the above description, combining unit CU comprises three feed stations 6, but may obviously comprise any number of feed stations 6 for supplying portions 3.

Transfer unit TUi is also fitted to frame 5, and comprises a spider 13 defined by a drum 14, which rotates continuously about a horizontal axis of rotation Y, and supports a number of peripheral members 15, each of which is fitted to drum 14 to rotate, as drum 14 rotates, about a respective axis of rotation parallel to axis of rotation Y of drum 14, so as to remain horizontal and parallel to itself at all times. Each member 15 supports a suction pickup head with two parallel suction seats, which withdraw two portion groups 4 simultaneously from two release drums 16a and 16b, i.e. the two suction seats of each suction pickup head of spider 13 simultaneously receive a portion group 4 from release drum 16a, and a portion group 4 from release drum 16b.

The two release drums 16a, 16b of transfer unit TUi are arranged side by side and parallel, and are mounted to rotate about respective horizontal axes of rotation parallel to each other and perpendicular to axis of rotation Y of drum 14; and each release drum 16a, 16b has radial arms 17 with respective suction seats on the end for receiving portion groups 4.

Finally, transfer unit TUi comprises a dividing assembly 18 for dividing a stream of portion groups 4 from combining unit CU into two symmetrical streams of portion groups 4, which are fed to the two release drums 16a, 16b, which in turn transfer respective portion groups 4 to spider 13. Dividing assembly 18 comprises a dividing drum 19a, which receives a first stream of portion groups 4 from combining unit CU and feeds it to release drum 16a over dividing drum 19a; and a dividing drum 19b, which receives a second stream of portion groups 4 from dividing drum 19a and feeds it to release drum 16b over dividing drum 19b.

The peripheral members of spider 13 are therefore each designed to receive a respective portion group 4 fed transversely from the last feed station 6*** of combining unit CU, and to transfer the respective portion group 4 axially to wrapping unit WU_X.

Wrapping unit WUi is also fitted to frame 5, receives portion groups 4 from transfer unit TUi, and feeds them forward axially.

Wrapping unit U_X supports a horizontal forming beam 19 with two grooves, inside which two half-strips, formed by longitudinally and symmetrically dividing a strip 20 of wrapping material, are wound about respective continuous successions of portion groups 4, arranged contacting end to end and travelling parallel to their central axis X, to form two continuous rods 21 of portions 3 (only one of which is shown in Figure 5e) . In a variation not shown, the two-line winding unit WUi described herein may be a one-line type.

As shown in Figure 2, winding unit WUi comprises a feed unit 22 for supplying strip 20 of wrapping material. Feed unit 22 for supplying strip 20 of wrapping material in turn comprises a reel-off station 23, where strip 20 of wrapping material is unwound off a reel 24 and fed to a set of guide rollers 25 designed to feed strip 20 of wrapping material to forming beam 19, where, divided for said two lines, it is wound about portion groups 4 to form respective rods 21.

Along forming beam 19, once strip 20 of wrapping material is wound, each continuous rod 21 of portions 3 is cut by a cutting head 26 into a succession of identical portion groups 4 (Figure 5f ) .

Each portion group 4 has a tubular wrap 27 coaxial with central axis X and covering the whole of portion group 4, which is then transferred to transfer unit U₂.

Transfer unit TU₂ comprises a spider 28 defined by a drum 29, which rotates continuously about an axis of rotation and supports a number of peripheral members 30, each of which has a suction pickup head which transfers portion groups 4, wrapped in tubular wraps 27, successively from forming beam 19 of wrapping unit WUi to an input drum 31, with peripheral suction seats for portion groups 4, of wrapping unit WU- .

Wrapping unit WU_: is also fitted to frame 5, receives portion groups 4 from transfer unit TU₂, and feeds them transversely from input drum 31 to a cutting drum 32, which cooperates with a blade 33 to cut each portion group 4 transversely in the middle, at portions 3A, into two specular portion groups 4 aligned coaxially with central axis X and contacting end to end.

Wrapping unit WU₂ then transfers the portion groups 4 from cutting drum 32 successively to a parting drum 34. On parting drum 34, each two portion groups 4, initially contacting end to end, are parted axially (by moving at least one portion group 4 axially) so they are positioned coaxial and a given axial distance apart. In other words, portion groups 4 are positioned axially end to end when loaded onto parting drum 34, and are spaced axially apart (as shown in Figure 5g) when unloaded off parting drum 34.

Parting drum 34 picks up portion groups 4 at an input station at cutting drum 32, and feeds them, spaced apart, to an output station at a downstream combining drum 35.

The axially spaced portion groups 4 are transferred to combining drum 35 at an input station 36. At a further input station 37 downstream from input station 36, each portion group 4 is ready to receive another portion 3D of desired length.

Wrapping unit WU₂ comprises a further feed unit 38 for supplying portions 3D. More specifically, a hopper 39 houses a mass of portions 3D and has a bottom outlet connected to a pickup drum 40, which cooperates with a blade 41 for cutting portions 3D transversely into portions 3D of desired length.

Portions 3D of desired length are transferred from pickup drum 40 to two transfer drums 42, and from the last transfer drum 42 to combining drum 35.

Combining drum 35 forms a portion group 4 in which two portions 3D of desired length are interposed coaxially between, and are positioned with respective ends contacting respective ends of, the two portion groups 4 from transfer unit TU? (as shown in Figure 5h) .

Portion groups 4 are transferred from combining drum 35 to an application drum 43. And a sheet 44 of wrapping material, supplied by a feed unit 45, is applied, over tubular wrap 27, to the portion group 4 in each seat on application drum 43. Each sheet 44 of wrapping material serves to mechanically connect portion groups 4 from transfer unit TU₂ and portions 3D of desired length (as shown in Figure 5i).

Each portion group 4 therefore has a tubular wrap coaxial with central axis X and completely covering tubular wrap 27, i.e. portion groups 4 from transfer unit TU? and portions 3D of desired length.

As shown in Figure 3, feed unit 45 comprises a reel-off station 46 where a single-width strip is unwound off a reel (not shown) ; and a set of guide rollers for feeding the strip to a transverse cutting station 47, which comprises a roller that cooperates with a counter-roller, equipped with a number of peripheral blades, to cut the continuous strip transversely into individual sheets 44 of wrapping material, which are then fed to application drum 43 and wound about portion groups 4 on application drum 43.

Portion groups 4 with sheets 44 of wrapping material are transferred from application drum 43 to a rolling drum 48, on which winding of sheet 44 of wrapping material about each portion group 4 is completed to form a tubular wrap coaxial with central axis X.

Wrapping unit WU? comprises a transfer drum 49, which receives portion groups 4 from rolling drum 48 and feeds them transversely to a cutting drum 50, which cooperates with a blade to transversely cut each portion group 4 in the middle, at portions 3D, into two cigarettes 2 coaxial with central axis X and contacting end to end (as shown schematically in Figure 51) . The end of assembly machine 1 comprises a so-called ^λ tip-turning' drum 51, on which one line of cigarettes 2 is flipped (as shown in Figure 5m) into the same orientation as the other line of cigarettes 2 alongside it, thus converting the two side by side lines of cigarettes 2 into one line of cigarettes 2 (obviously, with half the spacing of the two side by side lines of cigarettes 2 ) .

Finally, the end of assembly machine 1 comprises a number of drums 52, on which samples are taken, cigarettes 2 are checked, and any faulty cigarettes 2 are rejected, up to an output conveyor 53, by which cigarettes 2 are transferred from assembly machine 1 to a packing machine (not shown).

In another variation, not shown, of assembly machine 1, wrapping unit WU₂ does not comprise further feed unit 38 for supplying central portions 3D. In other words, cigarettes 2 only comprise portions 3A, 3B, 3C fed into combining unit CU, and the portion group 4 from combining unit CU is first wrapped in strip 20 of wrapping material to form tubular wrap 27 on wrapping unit WUi, and then in sheet 44 of wrapping material on wrapping unit WU₂.

In this case, sheets 44 of wrapping material serve to further improve the mechanical connection between portions 3 of portion groups 4 from transfer unit TU₂. So each portion group 4 therefore has a tubular wrap coaxial with central axis X and covering the whole of tubular wrap 27, i.e. portion groups 4 from transfer unit TU₂.

It is important to note that portion groups 4 are fed transversely (i.e. perpendicularly to their central axis X) along combining unit CU and wrapping unit U₂, but axially (i.e. parallel to their central axis X) along wrapping unit WUi .

It is important to note, as shown schematically in

Figure 4, that assembly machine 1 has a U-shaped layout, i.e. combining unit CU is positioned directly facing wrapping unit WU₂.

Combining unit CU and wrapping unit WUi are located at a 90° angle, with transfer unit TUi in between. In other words, combining unit CU and wrapping unit WUi form an L shape.

Wrapping units WUi and WU₂ are located at a 90° angle, with transfer unit TU₂ in between. In other words, wrapping units WUi and WU₂ form an L shape.

Combining unit CU is therefore parallel to wrapping unit WU? .

Moreover, all the portions 3 used to manufacture multicomponent cigarettes 2 travel along the U-shaped path indicated by the arrows in the Figure 4 diagram.

Assembly machine 1 described is cheap and easy to produce, by not being particularly complicated in design, and above all provides for effectively and efficiently producing cigarettes 2 or other tobacco articles comprising a number of different portions 3.

This is achieved by assembly machine 1 being adaptable to numerous combinations of portions 3 by simply adapting feed stations 6 of combining unit CU, and feed unit 38 of wrapping unit WU₂.

Moreover, assembly machine 1 described is compact and, above all, during normal operation or set-up, allows the operator a clear view of all its component units .

The work area of the operator, in fact, is confined to the U defined by the layout of assembly machine 1; which position allows operator control of, and fairly easy access to, combining unit CU, wrapping units WUi and WU₂, and transfer units TUi and TU₂.

Claims

1) An assembly machine (1) for producing multicomponent cigarettes (2), each comprising a number of portions (3), which have a central axis (X) and comprise at least one portion (3) defined by a filtering element, and at least another portion (3) defined by an aromatic, preferably tobacco-based, element; the assembly machine (1) comprising :

a combining unit (CU) for forming groups (4) of portions (3), each comprising at least two different first portions (3A, 3B, 3C) aligned axially and contacting end to end, and in which the groups (4) of portions (3) travel perpendicularly to their central axis (X) ;

a first wrapping unit (WUi) , which receives a succession of groups (4) of portions (3) from the combining unit (CU) , successively feeds the groups (4) of portions (3) parallel to their central axis (X), and winds a strip of wrapping material (20) about the succession of groups (4) of portions (3) to form at least one continuous rod (21) of portions (3); the first wrapping unit (WUi) comprising a cutting device (26) for cyclically and transversely cutting groups (4) of portions in respective tubular wraps (27) off the continuous rod (21) of portions (3); and a second wrapping unit ( U₂) , which receives the groups (4) of portions (3) in respective tubular wraps (27) from the first wrapping unit (WUi) , feeds the groups (4) of portions (3) in respective tubular wraps (27) perpendicularly to their central axis (X), and winds a sheet of wrapping material (44) about each group (4) of portions (3) in a respective tubular wrap (27); the assembly machine (1) being characterized by having a U-shaped layout, so that the combining unit (CU) is positioned facing the second wrapping unit (WU₂) .

2) An assembly machine (1) as claimed in Claim 1, and comprising a first transfer unit (TUi) interposed between the combining unit (CU) and the first wrapping unit (WUi) ; the combining unit (CU) and the first wrapping unit (WUi) being arranged at a 90° angle.

3) An assembly machine (1) as claimed in Claim 2, wherein the first transfer unit (TUi) has a spider (13), which receives the groups (4) of portions (3), travelling perpendicularly to their central axis (X) , from the combining unit (CU) , and feeds them, successively and parallel to their central axis (X) , to the first wrapping unit (WUi) .

4) An assembly machine (1) as claimed in one of the foregoing Claims, and comprising a second transfer unit

(TU₂) interposed between the first wrapping unit (WUi) and the second wrapping unit (WU₂) ; the first wrapping unit (WUi) and the second wrapping unit (WU₂) being arranged at a 90° angle.

5) An assembly machine (1) as claimed in Claim 4, wherein the second wrapping unit (WU₂) has a spider

(13), which receives the groups (4) of portions (3), travelling parallel to their central axis (X) , from the first wrapping unit (WUi) , and feeds them, perpendicularly to their central axis (X) , to the second wrapping unit (WU₂) ·

6) An assembly machine (1) as claimed in one of the foregoing Claims, wherein the second wrapping unit (WU₂) comprises :

a wrap feed unit (45) for supplying the sheets of wrapping material (44); and

a portion feed unit (38) located upstream from the wrap feed unit (45) to insert second portions (3D) into the groups (4) of portions (3).

7) An assembly machine (1) as claimed in Claim 6, wherein each sheet of wrapping material (44) is wound about a corresponding group (4) of portions (3) in a respective tubular wrap (27) to mechanically connect the second portion (3D) to the rest of the group (4) of portions ( 3 ) .

8) An assembly machine (1) as claimed in one of the foregoing Claims, wherein the second wrapping unit (WU₂) comprises a cutting device (50), which cuts each group (4) of portions (3) transversely into two cigarettes (2) .

9) An assembly machine (1) as claimed in one of the foregoing Claims, wherein :

the combining unit (CU) comprises a number of structurally similar feed stations (6), each for supplying a respective first portion (3A, 3B, 3C) to form the groups (4) of portions (3); and

each feed station (6) upstream from a preceding feed station (6) comprises an insertion drum (11), which receives the groups (4) of portions from the preceding feed station (6), receives respective first portions (3A, 3B, 3C) , and inserts the respective first portions (3A, 3B, 3C) into the groups (4) of portions (3).

10) An assembly machine (1) as claimed in Claim 9, wherein each feed station (6) comprises a hopper (7) containing a mass of respective first portions (3A, 3B, 3C) / a cutting drum (9) for cutting the first portions (3A, 3B, 3C) transversely to the desired length; and a pickup drum (8), which withdraws the first portions (3A, 3B, 3C) successively from the bottom of the hopper (7), cooperates with the cutting drum (9), and feeds the first portions (3A, 3B, 3C) of desired length to the insertion drum (11).

11) An assembly machine (1) as claimed in one of the foregoing Claims, wherein the first wrapping unit (WUi) comprises a forming beam (19), which receives the succession of groups (4) of portions (3) travelling parallel to their central axis (X) , and the strip of wrapping material (20) from a feed unit (22); the forming beam (19) being designed to wind the strip of wrapping material (20) about the succession of groups (4) of portions (3) to form said at least one continuous rod (21) of portions (3) .

12) An assembly machine (1) as claimed in one of

Claims 6 to 11, wherein the wrap feed unit (45) supplying the sheets of wrapping material (44) comprises a reel-off station (46) for unwinding a continuous strip; and a transverse cutting station (47) for cutting the continuous strip transversely into individual sheets of wrapping material (44);

and wherein the second wrapping unit (WU₂) comprises :

an application drum (43), which receives the groups (4) of portions and the sheets of wrapping material (44), which are wound about the groups (4) of portions; and

a rolling drum (48), which receives the groups (4) of portions from the application drum (43) and completes winding the sheets of wrapping material (44) about the groups (4) of portions. 13) An assembly machine (1) as claimed in Claim 12, wherein the second wrapping unit ( U₂) comprises a combining drum (35), which receives the groups (4) of portions from the first wrapping unit (WU_a) and the second portions (3D) of desired length from the portion feed unit (38), inserts the second portions (3D) of desired length into the groups (4) of portions (3), and feeds the groups (4) of portions to the application drum (43) .

14) An assembly machine (1) as claimed in one of Claims 6 to 13, wherein the portion feed unit (38) comprises a hopper (39) containing a mass of second portions (3D); a cutting drum (41) for cutting the second portions (3D) transversely to the desired length; and a pickup drum (40), which withdraws the second portions (3D) successively from the hopper (39) and cooperates with the cutting drum (41).

15) A method of producing multicomponent cigarettes (2), each comprising a number of portions (3), which have a central axis (X) and comprise at least one portion (3) defined by a filtering element, and at least another portion (3) defined by an aromatic, preferably tobacco-based, element; the method being implemented by an assembly machine (1) for producing multicomponent cigarettes (2), as claimed in one or more of Claims 1 to 14, and the method comprising the steps of : forming groups (4) of portions (3), each comprising at least two different first portions (3A, 3B, 3C) aligned axially, contacting end to end, and travelling perpendicularly to their central axis (X) ;

winding a strip of wrapping material (20) about the groups (4) of portions (3) travelling successively and parallel to their central axis (X) , to form at least one continuous rod (21) of portions (3); and

cutting groups (4) of portions in respective tubular wraps (27) off the continuous rod (21) of portions (3) by cyclically cutting the continuous rod (21) of portions (3) transversely;

the method being characterized by comprising the further step of winding a sheet of wrapping material (44) about the groups (4) of portions (3), in respective tubular wraps (27), travelling perpendicularly to their central axis (X) .

16) A method as claimed in Claim 15, and comprising the further step of inserting second portions (3D) into the groups (4) of portions (3) in respective tubular wraps (27), prior to winding the sheet of wrapping material (44) .