WO2017130098A1

WO2017130098A1 - Method and machine for making pieces of a multilayer, cylindrical tubular rod used to make substantially cylindrical smokers' articles, and the pieces made by the method and machine

Info

Publication number: WO2017130098A1
Application number: PCT/IB2017/050354
Authority: WO
Inventors: Marco Esposti; Giuliano Gamberini; Massimo Sartoni
Original assignee: G.D S.P.A.
Priority date: 2016-01-26
Filing date: 2017-01-24
Publication date: 2017-08-03
Also published as: RU2736437C2; EP3407742A1; JP2019509056A; JP7118897B2; KR20180108624A; RU2018125652A3; CN108601391B; ITUB20160048A1; JP2022116159A; RU2018125652A; EP3821721A1; CN108601391A

Abstract

A machine (100) for making pieces of a multilayer, cylindrical tubular rod (1) suitable for making substantially cylindrical smokers' articles comprises first means (101) for feeding at least a first continuous web (102), second means (103) for feeding a second continuous web (104), means (107) for forming a continuous, multilayer web (M) by superposing at least a first layer (2) and a second layer (5) and means (108) for feeding the continuous, multilayer web along a feed direction (X). Also provided are means (110) for forming the rod (1) around the feed direction (X) and means (111) for cutting the rod (1) into pieces. The machine (100) is configured to dispose the lateral edges (4, 7) of at least one between the first and the second layer (2, 5) in such a way as to make at least one end-to-end splice (3, 6). The machine (100) implements a method for making pieces of a multilayer, cylindrical tubular rod (1).

Description

DESCRIPTION

METHOD AND MACHINE FOR MAKING PIECES OF A MULTILAYER, CYLINDRICAL TUBULAR ROD USED TO MAKE SUBSTANTIALLY CYLINDRICAL SMOKERS' ARTICLES, AND THE PIECES MADE BY

THE METHOD AND MACHINE

Technical field

This invention relates to a method and a machine for making pieces of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles.

This invention also relates to pieces of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles.

Background art

As described in patent application WO2014/188318 machines are known in the prior art which are used to make smokers' articles where cylindrical components of smokers' products of any kind are wrapped in a multilayer web comprising strips suitable for imparting desired properties. The strips are made, for example, of a metallic material or a plastic material. Thus, the machine described in WO2014/188318 is suitable for directly making the pieces of smokers' articles by wrapping the multilayer web around the cylindrical components.

At present, therefore, no machine or method is available to provide pieces of a multilayer, cylindrical tubular rod suitable to be subsequently filled axially with the cylindrical components necessary to make the smokers' article. In effect, in this case, it would be necessary to have pieces of a multilayer, cylindrical tubular rod which comply with stringent dimensional and shape tolerances, with reference in particular to the internal diameter which has to receive the aforementioned components.

At present, prior art machines and methods are not capable of complying with specified tolerances because they are subject to errors in the positioning and/or alignment of individual layers of the multilayer web and to phase displacements between the process stations due, for example, to tension variations in the feeding of the continuous webs.

Disclosure of the invention

This invention therefore has for an aim to provide a method and a machine for making pieces of a multilayer, cylindrical tubular rod to overcome the disadvantages described above with reference to the prior art.

More specifically, the aim of this invention is to provide a method and a machine for making pieces of a multilayer, cylindrical tubular rod and capable of providing pieces of rod which comply with stringent dimensional and shape tolerances, with reference in particular to the internal diameter.

Another aim of this invention is to provide a method and a machine for making pieces of a multilayer, cylindrical tubular rod and capable of adapting to different types of products to be made and of making a reliable product which, in particular, guarantees complete closure along the circumferential direction and correct circumferential and longitudinal positioning of the different layers.

A further aim of this invention is to provide a piece of a multilayer, cylindrical tubular rod which is suitable for making substantially cylindrical smokers' articles and which allows the cylindrical components to be easily inserted at a later stage, guaranteeing the seal between the piece and the component for example in such a way that air can pass through the component.

These aims are achieved by a method and a machine for making pieces of a multilayer, cylindrical tubular rod having the features set out in one or more of the appended claims. These aims are also achieved by a piece of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles and having the features set out in one or more of the appended claims. Advantageously, carrying out the steps of the method in a single machine makes it possible to avoid phase displacements along the feed direction. Also, by wrapping the continuous, multilayer web around the feed direction to form a multilayer, cylindrical tubular rod and making at least one end-to-end splice, it is possible to reduce the shape and size irregularities of the piece, thereby complying with specified shape and size tolerances.

Advantageously, the piece of rod obtained comprises a first layer comprising a first splice, a second continuous layer comprising a second splice and, if necessary, a third continuous layer comprising a third splice, where at least one between the first and the second splice is made as an end-to-end splice.

Preferably, a first material is used which comprises one or more of the following: a metallic material, a plastic material, a paper material.

Preferably, a first, a second and a third layer are used, where the second and third layers have the same thickness. For example, the layers with the same thickness are obtained by feeding a single continuous web and dividing it longitudinally into two continuous web portions defining a second continuous web and a third continuous web. Alternatively, the second layer and the third layer have different thicknesses.

Preferably, both the first splice and the second splice are end-to-end splices. The third splice may be an end-to-end splice, offset relative to the first or the second splice, or it may be an overlapping splice, preferably offset relative to the first or the second splice.

Brief description of the drawings

Further features and advantages of the invention are more apparent from the following exemplary and therefore non-limiting description of a preferred and hence non-exclusive embodiment of a piece of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles, and a method and machine for making pieces of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles.

The invention is described below with reference to the accompanying drawings, which illustrate a non-limiting embodiment of it and in which:

- Figures 1 a, 1 b and 1 c show, respectively, a transverse cross section, a product schematic and a longitudinal cross section of a first embodiment of a multilayer, cylindrical tubular rod;

- Figures 2a-2c, 3a-3c, 4a-4c and 5a-5c show respective variants of Figures 1 a, 1 b and 1 c;

- Figures 6a-6c show a further variant of Figures 1 a, 1 b and 1 c and Figure 6d shows a further product schematic;

- Figure 7 is a schematic front view of a machine for making pieces of a multilayer, cylindrical tubular rod a filter rod, according to a first embodiment;

- Figure 8 is a schematic front view of a machine for making pieces of a multilayer, cylindrical tubular rod according to a second embodiment;

- Figure 9 shows an enlarged detail from Figure 7;

- Figure 10 is a side view of the detail of Figure 9;

- Figure 1 1 shows an enlarged detail from Figure 7;

- Figure 12 is a side view of the detail of Figure 1 1 .

Detailed description of preferred embodiments of the invention

With reference to the accompanying drawings, the numeral 1 denotes a multilayer, cylindrical tubular rod from which pieces suitable for making substantially cylindrical smokers' articles are obtained.

The rod 1 , and thus a piece of it not illustrated, comprises a first layer 2 of a first material. The first layer 2 is spliced longitudinally to form a first splice 3 of respective lateral edges 4 of the first layer 2.

The rod 1 , and thus a piece of it not illustrated, comprises a second layer 5 of a second material. The second layer 5 is spliced longitudinally to form a second splice 6 of respective lateral edges 7 of the second layer 5.

The first layer 2 occupies a radially inner position relative to the second layer 5 in both the piece and the rod 1 .

The second layer 5 is continuous along a main direction of extension "X" of the rod 1 , coinciding with the feed direction of the rod during production of the pieces.

At least one between the first splice 3 and the second splice 6 is made as an end-to-end splice, that is, a splice made without overlapping the two respective lateral edges.

The first material and the second material are different. For example, the first material may be a metallic material and the second material may be a paper material.

Figures 1 a and 1 c illustrate a rod 1 where the first layer 2 is also continuous along the main direction of extension "X" of the rod 1 . Further, both the first splice 3 and the second splice 6 are end-to-end splices and are offset from each other, that is, they are disposed at different angular positions around the direction "X". Figure 1 b illustrates a step in the production of the rod 1 from a continuous multilayer web "M" comprising the first layer 2 and the second layer 5, both laid out flat. Also illustrated is an intermediate layer 8 of adhesive material interposed between the first layer 2 and the second layer 5.

Figures 2a and 2c illustrate a rod 1 comprising a third layer 9 occupying a radially outer position relative to the first layer 2 and second layer 5. The third layer 9 is spliced longitudinally to form a third splice 10 of respective lateral edges 4 of the third layer 9. Both the first splice 3 and the second splice 6 are end-to-end splices and preferably are disposed at the same angular position around the direction "X". The third splice 10 is an end-to- end splice and is offset relative to the first and second splices, that is, disposed at a different angular position around the direction "X".

Again with reference to Figures 2a and 2c, the first layer 2 is discontinuous and comprises, along the feed direction, a sequence of strips 14 alternated with empty spaces 15. In this case, complete closure of the rod 1 is guaranteed by the third layer 9 and the third splice 10 offset from the other splices.

Figure 2b illustrates a step in the production of the rod 1 from a continuous multilayer web "M" comprising the first layer 2, the second layer 5 and the third layer 9, all laid out flat. Also illustrated is the intermediate layer 8 of adhesive material interposed between the first layer 2 and the second layer 5 and a further intermediate adhesive layer 12 interposed between the second layer 5 and the third layer 9. The third layer is offset along a direction perpendicular to the direction "X" relative to the first and second layers, so as to offset the respective third splice 10 relative to the first splice 3 and second splice 6.

The second layer 5 and the third layer 9 have the same thickness and are preferably obtained by dividing a single continuous web longitudinally, as described hereinafter.

Figures 3a and 3c illustrate a rod 1 comprising the third layer 9 occupying a radially outer position relative to the first layer 2 and second layer 5. The third layer 9 is spliced longitudinally to form the third splice 10 of respective lateral edges 4 of the third layer 9. Unlike the rod of Figures 2a and 2c, the second layer 5 and the third layer 9 have different thicknesses: in particular, the second layer 5 is smaller in thickness than the third layer 9. In this case, the function of the second layer 5 is that of transporting the first layer 2. Thanks to the reduced thickness, it is easier to wrap it around itself and it may be made in such a way as to better absorb the adhesive material of the intermediate layer 8. The third layer 9 acts mainly as a supporting layer and gives the rod 1 and the related pieces the stiffness necessary to keep their shape.

Again with reference to Figures 3a and 3c, the first layer 2 is discontinuous and comprises, along the feed direction, the sequence of strips 14 alternated with empty spaces 15. In this case, complete closure of the rod 1 is guaranteed by the third layer 9 and the third splice 10 offset from the other splices. Figure 3b is similar to Figure 2b.

Figures 4a and 4c illustrate a rod 1 comprising the third layer 9 occupying a radially outer position relative to the first layer 2 and second layer 5. The third layer 9 is spliced longitudinally to form the third splice 10 of respective lateral edges 4 of the third layer 9. Unlike the rod of Figures 2a and 2c, the second layer 5 and the third layer 9 have different thicknesses: in particular, the second layer 5 is larger in thickness than the third layer 9. In this case, the second layer 5 acts both as a layer for transporting the first layer 2 and as a supporting layer giving the rod 1 and the related pieces the stiffness necessary to keep their shape. The functions of the third layer 9 are mainly to improve aesthetic appearance and to help keep the second layer 5 closed.

Again with reference to Figures 4a and 4c, the first layer 2 is discontinuous and comprises, along the feed direction, the sequence of strips 14 alternated with empty spaces 15. In this case, complete closure of the rod 1 is guaranteed by the third layer 9 and the third splice 10 offset from the other splices. Figure 4b is similar to Figure 2b.

Figures 5a and 5c illustrate a rod 1 comprising the third layer 9 occupying a radially outer position relative to the first and second layers. The third layer 9 is spliced longitudinally to form the third splice 10 of respective lateral edges 4 of the third layer 9. Unlike the rod of Figures 2a and 2c, the third splice 10 is an overlapping splice and is preferably offset from the first splice 3 or the second splice 6, that is, is disposed at a different angular position around the direction "X". Again with reference to Figures 5a and 5c, the first layer 2 is discontinuous and comprises, along the feed direction, a sequence of strips 14 alternated with empty spaces 15. In this case, the complete closure of the rod 1 is guaranteed by the third layer 9 and the third splice 10 which is offset from the other splices and is an overlapping splice.

Figure 5b illustrates a step in the production of the rod 1 from a continuous multilayer web "M" comprising the first layer 2, the second layer 5 and the third layer 9, all laid out flat. Also illustrated is the intermediate layer 8 of adhesive material interposed between the first layer 2 and the second layer 5 and the further intermediate adhesive layer 12 interposed between the second layer 5 and the third layer 9. The third layer 9 is aligned at least at one of the lateral edges of the first layer 2 and second layer 5.

Figures 6a and 6c illustrate a rod 1 comprising the third layer 9 occupying a radially outer position relative to the first and second layers. The third layer 9 is spliced longitudinally to form the third splice 10 of respective lateral edges 4 of the third layer 9. Unlike the rod of Figures 2a and 2c, the first splice 3 is an overlapping splice, the second splice 6 is an end-to- end splice and the third splice 10 is an overlapping splice and is preferably offset from the first splice 3 or the second splice 6. The second layer 5 and the third layer 9 have different thicknesses: in particular, the second layer 5 is larger in thickness than the third layer 9.

Again with reference to Figures 6a and 6c, the first layer 2 is discontinuous and comprises, along the feed direction, a sequence of strips 14 alternated with empty spaces 15. In this case, complete closure of the rod 1 is guaranteed by the third layer 9 and the third splice 10 offset from the other splices. The continuity of the first layer 2 along a circumferential direction is guaranteed by the first splice 3, which is an overlapping splice.

Figure 6b illustrates a step in the production of the rod 1 from a continuous multilayer web "M" comprising the first layer 2 and the second layer 5, which are laid out flat and which, when subsequently wrapped on themselves, form an intermediate rod 13. Also illustrated is the intermediate layer 8 of adhesive material interposed between the first layer 2 and the second layer 5. Figure 6d illustrates a further step in the production of the rod 1 from the intermediate rod 13 and the third layer 9. The third layer 9 will be wrapped around the intermediate rod 13 to form the rod 1 . Also shown is the further intermediate adhesive layer 12 interposed between the second layer 5 and the third layer 9.

In all the examples illustrated and/or described above, the first material may comprise one or more of the following: a metallic material, a plastic material, a paper material.

Figures 7 and 8 illustrate two possible embodiments of a machine 100 for making pieces of a multilayer, cylindrical tubular rod 1 suitable for making substantially cylindrical smokers' articles. More specifically, the machine 100 is adapted to make a piece of a rod 1 according to one or more of the examples illustrated and/or described above.

The machine 100 comprises first means 101 for feeding at least a first continuous web 102 of a first material suitable for making the first layer 2 of a continuous, multilayer web "M" and of the rod 1 .

The machine 100 comprises second means 103 for feeding a second continuous web 104 of the second material suitable for making a second continuous layer 5 of the continuous, multilayer web "M" and of the rod 1 . The first continuous web 102 and/or the second continuous web 104 are preferably provided on rolls "B" unwound by respective means 102, 103 for feeding the continuous webs.

Located along the feed path of the second continuous web 104 there is a gluing device 105 configured to apply a layer of adhesive material on the second continuous web 104 to define the intermediate layer 8 of adhesive material of the rod 1 . The intermediate layer 8 is preferably continuous. The gluing device 105 may be embodied, for example by rollers, sprayers or in other ways.

Located along the feed path of the first continuous web 102 there may be a cutting device 106 configured to cut the first continuous web 102 into strips 14. The cutting device 106 is provided when the first layer 2 is discontinuous, that is to say, when it comprises a sequence of strips 14 alternated with empty spaces 15. The cutting device 106 may be a cutter of the impact or scissor type or it may be embodied in other ways.

The numeral 107 denotes means for forming the continuous, multilayer web "M" by superposing at least the first layer 2 and the second layer 5. These means may, for example, comprise a bed 107a embodied by a conveyor 108 adapted to receive the second continuous web 104 defining the second layer 5 and the strips 14 of the first continuous web 102 defining the first, discontinuous layer 2 (alternatively, the conveyor receives the first continuous web 102 defining the first continuous layer 2). The conveyor 108 is also adapted to feed the continuous, multilayer web "M" along the feed direction "X" and thus also embodies means for feeding the continuous, multilayer web "M" along the feed direction "X". Preferably, the conveyor 108 receives the second continuous web 104 with the intermediate layer 8 which is applied thereon and on which the strips 14 of the first continuous web 102 are placed by a drum 109 associated with the cutting device 106.

Downstream of the drum 109, therefore, the continuous, multilayer web "M" obtained is such that the first layer 2 in the rod 1 occupies a radially inner position relative to the second layer 5.

Downstream of the conveyor 108, means 1 10 are provided for forming the rod 1 around the feed direction "X" making the splices of the layers making up the rod itself;

The means 1 10 may comprise a forming beam 1 10a having a groove whose cross section is variable along the feed direction "X" in such a way as to wrap the continuous, multilayer web "M" around the feed direction "X" to make the rod 1.

Downstream of the means 1 10 for forming the rod 1 there are means 1 1 1 for cutting the rod 1 into pieces.

Advantageously, the machine 100 is configured to dispose the lateral edges of at least one between the first layer 2 and the second layer 5 in such a way as to make at least one between the first splice 3 and the second splice 6 as an end-to-end splice.

As illustrated in Figures 7 and 8, third means 1 12 may be provided for feeding a third continuous web 1 13 of a third material suitable for making the third layer 9 of the rod 1 . The third continuous web 1 13, hence the third layer 9, is disposed in such a way as to occupy, in the rod 1 , a radially outer position relative to the first layer 2 and second layer 5.

Along the feed path of the third continuous web 1 13 there is a gluing device 105a configured to apply the further intermediate adhesive layer 12 interposed between the second layer 5 and the third layer 9. The gluing device 105 may be embodied, for example by rollers, sprayers or in other ways.

In the example shown in Figure 7, the third means 1 12 feed the third web 1 13 downstream of the conveyor 108 and upstream of the means 1 10 to form the third layer 9. Thus, the first layer 2, the second layer 5 and the third layer 9 form the continuous, multilayer web "M" and are wrapped together on themselves along the forming beam 1 10a.

If necessary, the machine 100 may comprise two blades 1 14 located on opposite sides of the continuous, multilayer web "M" and configured to trim the edges thereof. In the case of Figure 7, the blades 1 14 are circular blades which use as their anvil element a flat surface 1 15 on which at least one active portion of the conveyor 108 slides. The blades are located downstream of the drum 109 and thus trim the continuous, multilayer web "M" comprising the first layer 2 and the second layer 5. If necessary, the machine 100 may comprise a forming device 1 16 configured to preform the continuous, multilayer web "M" before it is wrapped on itself to form the rod 1 . Figures 1 1 and 12 illustrate a possible example of the forming device 1 16, which can be used in any machine for forming a rod 1 and which comprises a moulded groove 1 17, adapted to receive the continuous, multilayer web "M", and a forming element - for example a wheel 1 18 - which fits at least partly in the moulded groove 1 17 to make in the continuous, multilayer web a grooved shape extending along the middle of it in the feed direction "X". The forming device 1 16 may act on a continuous, multilayer web "M" comprising only the first layer 2 and the second layer 5 or, as illustrated in Figure 7, on a continuous, multilayer web "M" comprising the first layer 2, the second layer 5 and the third layer 9.

The machine 100 illustrated in Figure 8 differs from the machine illustrated in Figure 7 in that it comprises two forming beams. The first forming beam 1 10a is similar to the one illustrated in Figure 7 and is configured to make the rod 1 . A further forming beam 1 19 is located at the conveyor 108 to wrap the continuous, multilayer web "M", comprising the first layer 2 and the second layer 5, on itself to form the intermediate rod 13. The third continuous web 1 13 is fed between the further forming beam 1 19 and the forming beam 1 10a to wrap the third continuous web 1 13 around the intermediate rod 13 to form the rod 1 .

In use, the machine 100 is adapted to function according to a method for making pieces of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles.

The above mentioned method comprises a step a) of feeding at least a first continuous web 102 of a first material suitable for making a first layer 2 of a continuous, multilayer web "M". This step is carried out, for example, by the first feed means 101 .

The above mentioned method comprises a step b) of feeding a second continuous web 104 of a second material suitable for making a second continuous layer 5 of the continuous, multilayer web "M". This step is carried out, for example, by the second feed means 103.

Preferably, there is a step f) of feeding a third continuous web 1 13 of a third material suitable for making a third layer 9 of the rod 1 . The third layer 9 is disposed in such a way as to occupy, in the rod 1 , a radially outer position relative to the first layer 2 and second layer 5.

The above mentioned method comprises a step c) of forming the continuous, multilayer web "M" by superposing at least the first layer 2 and the second layer 5, where the first layer 2 is positioned in such a way as to occupy, in the rod 1 , a radially inner position relative to the second layer 5, and feeding the continuous, multilayer web "M" along a feed direction "X". This step is carried out, for example, at the means 107 and at the conveyor 108.

The above mentioned method comprises a step d) of wrapping the continuous, multilayer web "M" around the feed direction "X", making at least a first splice 3 of the lateral edges of the first layer 2 and a second splice 6 of the lateral edges of the second layer 5, to form the rod 1 . This step may be carried out in the forming beam 1 10a to form a continuous, multilayer web "M" comprising the first layer 2, the second layer 5 and possibly also the third layer 9, or in the forming beam 1 19 to form a continuous, multilayer web "M" comprising the first layer 2 and the second layer 5. In the latter case, the forming of the rod 1 may, if necessary, be completed by wrapping the third layer 9 around the intermediate rod 13. The above mentioned method comprises a step e) of cutting the rod 1 into pieces.

Steps a) to e) are carried out in a single machine 100 to make a multilayer, cylindrical tubular rod 1 . Also, step d) is carried out by disposing the lateral edges of at least one between the first layer 2 and the second layer 5 in such a way as to make at least one between the first splice 3 and the second splice 6 as an end-to-end splice.

Preferably, there is a step of making strips 14 of the first continuous web 102 and making a first, discontinuous layer 2 along the feed direction "X" where the first, layer 2 comprises, along the feed direction, a sequence of strips 14 alternated with empty spaces 15. This step is carried out, for example, by the cutting device 106.

If necessary, there may be a step of feeding a single continuous web suitable for making the second layer 5 and the third layer 9 and a step of dividing the single continuous web longitudinally into two continuous web portions respectively defining the second continuous web 104 and the third continuous web 1 13. In this case, the second continuous web 104 and the third continuous web 1 13 have the same thickness. Alternatively, the second continuous web 104 and the third continuous web 1 13 have different thicknesses.

As illustrated in Figure 7, step c) comprises first forming the continuous, multilayer web "M" by superposing the first layer 2 and the second layer 5 and then adding the third layer 9. The continuous, multilayer web "M" thus obtained (that is to say, comprising the first layer 2, the second layer 5 and the third layer 9) is wrapped on itself around the feed direction "X" to form the rod 1 .

In a possible embodiment, step d) may be carried out by disposing the lateral edges of the first layer 2 in such a way as to make a first end-to- end splice 3 and disposing the lateral edges of the second layer 5 in such a way as to make a second end-to-end splice 6.

In this case, step c) might comprise the step of offsetting the third layer 9 relative to at least one between the first and the second layer along a direction perpendicular to the feed direction "X" and step d) might be carried out by disposing the lateral edges of the third layer in such a way as to make a third end-to-end splice 10 (Figures 2a-4a). Alternatively, step d) might be carried out by disposing the lateral edges of the third layer 9 in such a way as to make the third splice an overlapping splice (Figure 5a).

As illustrated in Figure 8, step c) comprises forming the continuous, multilayer web "M" by superposing the first layer 2 and the second layer 5. Next, the continuous, multilayer web "M" is wrapped on itself to form an intermediate rod 13 and juxtaposed with the third continuous web 1 13, that is, with the third layer 9, to wrap the third continuous web 1 13 around the intermediate rod 13 to form the rod 1 . In other words., there is a step g) of wrapping the third layer 9 around the intermediate rod 13 already formed by wrapping the first and second layers around themselves. Preferably, step d) may be carried out by disposing the lateral edges 4 of the first layer 2 in such a way as to make at least a first, overlapping splice 3 and disposing the lateral edges 7 of the second layer 5 in such a way as to make a second, end-to-end splice 6. Preferably, step g) is carried out by disposing the lateral edges 1 1 of the third layer 9 in such a way as to make a third, overlapping splice 10 (Figure 6a).

If necessary, the edges of the continuous, multilayer web "M" might be trimmed before the web is wrapped on itself to form a multilayer, cylindrical tubular rod. More specifically, the edges of the continuous, multilayer web "M" formed by the first layer 2 and second layer 5 might be trimmed in an embodiment where there is a third layer 9.

If necessary, before the continuous, multilayer web "M" is wrapped on itself to form the rod 1 , it might be preformed by making in the continuous, multilayer web a grooved shape extending along the feed direction "X". In an alternative not illustrated, the machine 100 is adapted to make rods 1 which comprise only the first layer 2 and the second layer 5 with a first and a second end-to-end splice. In this case, the first layer 2 is continuous along the feed direction "X" and the first layer 2 and second layer 5 are offset in a direction perpendicular to the feed direction "X". Even independently of what is described in the foregoing, the method according to this invention may involve a second layer 2 and a third layer 9 having the same thickness or different thicknesses. In the first case, there may be a step of feeding a single continuous web suitable for making the second and third layers and a step of dividing the single continuous web longitudinally into two continuous web portions respectively defining the second continuous web 104 and the third continuous web 1 13.

Claims

1 ) A method for making pieces of a multilayer, cylindrical tubular rod (1 ) suitable for making substantially cylindrical smokers' articles, comprising the steps of:

a) feeding at least a first continuous web (102) of a first material suitable for making a first layer (2) of a continuous, multilayer web (M);

b) feeding a second continuous web (104) of a second material suitable for making a second continuous layer (5) of the continuous, multilayer web (M);

c) forming the continuous, multilayer web (M) by superposing at least the first layer (2) and the second layer (5), wherein the first layer (2) is positioned in such a way as to occupy, in the rod (1 ), a radially inner position relative to the second layer (5), and feeding the continuous, multilayer web (M) along a feed direction (X);

d) wrapping the continuous, multilayer web (M) around the feed direction (X), making at least a first splice (3) of the lateral edges (4) of the first layer (2) and a second splice (6) of the lateral edges (7) of the second layer (5), to obtain a rod (1 );

e) cutting the rod (1 ) into pieces;

characterized in that steps a)-e) are performed on a single machine (100) for making a multilayer, cylindrical tubular rod (1 ) wherein the step d) is accomplished by disposing the lateral edges (4, 7) of at least one between the first and the second layer (2, 5) in such a way as to make at least one between the first and the second splice (3, 6) as an end-to-end splice.

2) The method for making pieces of a multilayer, cylindrical tubular rod according to claim 1 , characterized in that it comprises a step f) of feeding a third continuous web (1 13) of a third material suitable for making a third layer (9) of the rod (1 ), wherein the third layer (9) is positioned in such a way as to occupy, in the rod (1 ), a radially outer position relative to the first and second layers (2, 5).

3) The method for making pieces of a multilayer, cylindrical tubular rod according to claim 2, characterized in that step c) comprises forming the continuous, multilayer web (M) by superposing the first layer (2), the second layer (5) and the third layer (9) and preferably characterized in that step d) is accomplished by disposing the lateral edges (4) of the first layer (2) in such a way as to make a first end-to-end splice (3) and disposing the lateral edges (7) of the second layer (5) in such a way as to make a second end-to-end splice (6).

4) The method for making pieces of a multilayer, cylindrical tubular rod according to claim 3, characterized in that step c) comprises forming the step of offsetting the third layer (9) relative to at least one between the first and the second layer (2, 5) along a direction perpendicular to the feed direction (X) and in that step d) is accomplished by disposing the lateral edges (1 1 ) of the third layer (9) in such a way as to make a third end-to-end splice (10) or characterized in that step d) is accomplished by disposing the lateral edges (1 1 ) of the third layer (9) in such a way as to make a third, overlapping splice (10).

5) The method for making pieces of a multilayer, cylindrical tubular rod according to claim 2, characterized in that the continuous, multilayer web (M) formed by superposing the first layer (2) and the second layer (5) is wrapped to form an intermediate rod (13) with which the third layer (9) is juxtaposed and characterized in that it comprises a step g) of wrapping the third layer (9) around the first and second layers (2, 5) which are already wrapped to form the intermediate rod (13), making a third splice (10) of the lateral edges (1 1 ) of the third layer (9), the method being preferably characterized in that step d) is accomplished by disposing the lateral edges (4) of the first layer (2) in such a way as to make at least a first, overlapping splice (3) and disposing the lateral edges (7) of the second layer (5) in such a way as to make a second, end-to-end splice (6), the method being preferably characterized in that step g) is accomplished by disposing the lateral edges (1 1 ) of the third layer (9) in such a way as to make a third, overlapping splice (10).

6) The method for making pieces of a multilayer, cylindrical tubular rod according to one or more of the preceding claims, characterized in that it comprises trimming the edges of the continuous, multilayer web (M) before wrapping it and forming a multilayer, cylindrical tubular rod (1 ).

7) The method for making pieces of a multilayer, cylindrical tubular rod according to one or more of the preceding claims, characterized in that it comprises preforming the continuous, multilayer web (M), before wrapping it and forming a multilayer, cylindrical tubular rod (1 ), producing a central shape extending along the middle of the continuous, multilayer web in the feed direction (X).

8) The method for making pieces of a multilayer, cylindrical tubular rod according to one or more of the preceding claims, characterized in that it comprises a step of making strips (14) of the first continuous web (102) and making a first, discontinuous layer (2) along the feed direction (X) wherein the first, discontinuous layer (2) comprises, along the feed direction, a sequence of strips (14) alternated with empty spaces (15).

9) The method for making pieces of a multilayer, cylindrical tubular rod according to one or more of claims 1 to 7, characterized in that it comprises a step of making a first, continuous layer (2) along the feed direction (X) and preferably characterized in that step c) comprises the step of offsetting the first and second layers (2, 5) in a direction perpendicular to the feed direction (X) and in that step d) is accomplished by positioning end to end the lateral edges (4) of the first layer (2) and the lateral edges (7) of the second layer (5). 10) A machine (100) for making pieces of a multilayer, cylindrical tubular rod suitable for making substantially cylindrical smokers' articles, characterized in that it comprises:

first means (101 ) for feeding at least a first continuous web (102) of a first material suitable for making a first layer (2) of a continuous, multilayer web (M);

second means (103) for feeding a second continuous web (104) of a second material suitable for making a second continuous layer (5) of the continuous, multilayer web (M);

means (107) for forming the continuous, multilayer web (M) by superposing at least the first layer (2) and the second layer (5), wherein the first layer (2) is positioned in such a way as to occupy, in the rod (1 ), a radially inner position relative to the second layer (5), and means (108) for feeding the continuous, multilayer web along a feed direction (X);

means (1 10) for forming the rod (1 ) around the feed direction (X) making the splices (3, 6, 10) of the layers making up the rod itself;

means (1 1 1 ) for cutting the rod (1 ) into pieces;

wherein the machine (100) is configured to dispose the lateral edges (4, 7) of at least one between the first and the second layer (2, 5) in such a way as to make at least one between the first and the second splice (3, 6) as an end-to-end splice.

1 1 ) The machine (100) for making pieces of a multilayer, cylindrical tubular rod according to claim 10, characterized in that it comprises third means (1 12) for feeding a third continuous web (1 13) of a third material suitable for making a third layer (9) of the rod (1 ), wherein the third layer (9) is positioned in such a way as to occupy, in the rod (1 ), a radially outer position relative to the first and second layers (2, 5).

12) The machine (100) for making pieces of a multilayer, cylindrical tubular rod according to claim 1 1 , characterized in that the means (1 10) for forming the rod (1 ) around the feed direction (X) comprise an upstream forming beam (1 19) configured to wrap the continuous, multilayer web (M) comprising the first layer (2) and the second layer (5) and to form an intermediate rod (13) and in that it comprises a downstream forming beam (1 10a) configured to wrap the third continuous web (1 13) around the intermediate rod (13) to form the rod (1 ).

13) The machine for making pieces of a multilayer, cylindrical tubular rod according to one or more of claims 10 to 12, characterized in that it comprises two blades (1 14) located on opposite sides of the continuous, multilayer web (M) and configured to trim the edges thereof.

14) The machine for making pieces of a multilayer, cylindrical tubular rod according to one or more of claims 10 to 13, characterized in that it comprises a forming device (1 16) configured to preform the continuous, multilayer web (M) before it is wrapped to form the rod (1 ).

15) A piece of a multilayer, cylindrical tubular rod (1 ) suitable for making substantially cylindrical smokers' articles, comprising:

a first layer (2) of a first material comprising a first splice (3) of respective lateral edges (4) and a second continuous layer (5) of a second material comprising a second splice (6) of respective lateral edges (7), wherein the first layer (2) occupies a radially inner position relative to the second layer (5),

characterized in that at least one between the first and the second splice (3, 6) is made as an end-to-end splice.

16) The piece of a multilayer, cylindrical tubular rod according to claim 15, characterized in that it comprises a third continuous layer (9) of a third material occupying a radially outer position relative to the first and second layers (2, 5) and comprising a third splice (10) of respective lateral edges (1 1 ), the piece being preferably characterized in that the first splice (3) is an overlapping splice, the second splice (6) is an end-to-end splice and the third splice (10) is an overlapping splice, preferably offset relative to the first and second splices (3, 6). 17) The piece of a multilayer, cylindrical tubular rod according to claim 16, characterized in that the second layer (5) and the third layer (9) differ in thickness.

18) The piece of a multilayer, cylindrical tubular rod according to one or more of claims 15 to 17, characterized in that the first layer (2) is continuous along the feed direction (X) and in that the first and second splices (3, 6) are made end to end and offset from each other or characterized in that the first layer (2) is discontinuous and comprises, along the feed direction (X), a sequence of strips (14) alternated with empty spaces (15).