WO2016097901A2

WO2016097901A2 - Segment of multi-segment article of the tobacco industry, apparatus for the manufacture of segments of multi-segment articles, and method and apparatus for putting together segments of a continuous multi-segment rod

Info

Publication number: WO2016097901A2
Application number: PCT/IB2015/058967
Authority: WO
Inventors: Radoslaw Figarski
Original assignee: International Tobacco Machinery Poland Sp zoo
Current assignee: International Tobacco Machinery Poland Sp zoo
Priority date: 2014-12-16
Filing date: 2015-11-19
Publication date: 2016-06-23
Anticipated expiration: 2017-06-16
Also published as: PL410571A1; WO2016097901A3

Abstract

The object of the application is a segment of a multi-segment segment article of the tobacco industry characterised by comprising a sheath (4) forming a sidewall of the segment (S2), and a loose material (2) placed inside the sheath (4), whereas the segment (S2) is made outside the carrier on which the segments of the multi-segment article are put together. Furthermore, the object of the application is an apparatus for the manufacture of segments (S2) of multi-segment articles of the tobacco industry characterised by comprising: a container for the sheaths (4) forming the sidewall of the segment (S2), a loose material (2) container unit designed to feed the loose material (2) to the sheath (4), inserting means designed to bring the loose material (2) into the sheath (4).

Description

Segment of multi-segment article of the tobacco industry, apparatus for the manufacture of segments of multi-segment articles, and method and apparatus for putting together segments of a continuous multi-segment rod

The object of the invention is a segment of a multi-segment article of the tobacco industry, apparatus for the manufacture of segments of multi-segment articles, and a method and an apparatus for putting together segments of a continuous multi-segment rod.

The invention may be used in the tobacco industry, in particular in the production of multi-segment articles such as multi-segment filters.

Various kinds of filter materials are commonly used in the tobacco industry. These may be for example fibrous, powder, granulated, porous, solid and other materials, whereas multi-segment filters are commonly used, and each segment contains a different filter material. Granulated materials are usually placed loose between other segments of a solid form.

Many solutions used for placing granulated materials between other segments are known from the prior art. The US 3,482,488 document shows an apparatus designed to feed granulated material from the chamber simultaneously to multiple spaces among the segments, while the US 4,015,514 document shows an apparatus designed to feed the material into a single space at a time.

According to a method known form the WO 2004/056221 A1 publication, granulated material is poured both on the segments and into the spaces among them, and excessive granulated material is received. Also methods for the feeding of measured portions of granulated material are known, for example form the documents US 3,312,152 and US 3,570,557. The document EP 0 554 100 shows a filling apparatus for feeding granulated material, the apparatus being provided with a special belt with holes through which the granulated material is fed, in order to reduce the machine contamination.

The US 3,807,286 patent shows a method for the feeding granulated material directly to a space formed by two segments and a paper wrapper wrapped around them, the paper wrapper having holes for the feeding of granulated material. A drawback of all abovementioned known solutions is that the amount of granulated material placed into successive spaces between the segments is not repeatable due to the speed of movement of the segments at which it is difficult to perform a precise measurement of the amount of granulated material, and in addition a part of granulated material may be subject to degradation or rebound. In order to achieve the required efficiency of tobacco smoke filtering, the space among the segments is to be filled to the maximum. In case of filling the space among the segments only to a certain extent a part of the tobacco smoke will pass above the granulated material, and not through such material. Therefore, it was necessary to develop a method and an apparatus eliminating the problem of incomplete filling of the spaces among the segments.

The substance of the invention is a segment of a multi-segment article of the tobacco industry characterised by comprising a sheath forming a sidewall of the segment and a loose material placed inside the sheath, whereas the segment is made outside the carrier on which the segments of the multi- segment article are put together.

Moreover, the segment according to the invention is characterised in that the sheath forming the sidewall of the segment is open at both sides.

The segment according to the invention is characterised in that the sheath forming the sidewall of the segment is open at one side, while at the closed side it is made of a material which is permeable to gases.

The segment according to the invention is characterised in that the material of which the sheath was made was selected from a group comprising: paper, cardboard, plastics, polymer material, film of a material of plant origin.

The segment according to the invention is characterised in that the loose material was selected from the group comprising: activated charcoal, tobacco, tobacco processing products, polymer material and material of plant origin.

The segment according to the invention is characterised in that the open end pieces of the sheath are protected by a material keeping the loose material inside the sheath.

The segment according to the invention is characterised in that the material keeping the loose material inside the sheath was selected from a group comprising: paper with porous structure, mesh, fabric, materials permeable to gases in the form of honeycomb.

The segment according to the invention is characterised in that the loose material is measured out by weight or by volume.

Furthermore, the substance of the invention is an apparatus for the manufacture of segments of multi- segment articles of the tobacco industry characterised by comprising: a container for shaped sheaths forming the sidewall of the segment, a loose material container unit designed to feed the loose material to the shaped sheath, filling means designed to bring the loose material into the sheath.

The apparatus according to the invention is characterised in that the filling means comprise a seat receiving the shaped sheaths, a metering chamber and a piston bringing the loose material from the metering chamber into the cylindrical sheath.

The apparatus according to the invention is characterised by comprising a sheath closing unit putting the material holding the loose material at open end pieces.

The apparatus according to the invention is characterised by additionally comprising means designed to measure out the loose material.

The substance of the invention is also a method for putting together of segments of a multi-segment continuous rod characterised in that a previously made segment of a multi-segment article of the tobacco industry comprising a shaped sheath forming the sidewall of the segment and the loose material placed inside the sheath are received, whereas the segment is made outside the carrier on which the segments of the multi-segment article are put together, the segment containing loose material in the cylindrical sheath is placed between the segments on the carrier on which the segments of the multi-segment article are put together.

The method according to the invention is characterised in that afterwards the formed segment train is wrapped with a common wrapping material so that a multi-segment continuous rod is formed, after which the formed multi-segment continuous rod is cut into individual multi-segment rods, whereas an individual multi-segment rod may be cut into individual multi-segment rods.

The method according to the invention is characterised in that the segment containing the loose material is placed between the segments on a drum conveyor.

The method according to the invention is characterised in that the segment containing the loose material is placed between the segments on a belt conveyor.

The method according to the invention is characterised in that the segments containing the loose material are separated from one another by means of a separating unit.

The method according to the invention is characterised in that the segment containing the loose material are separated from one another by means of a separating unit comprising two separating plates, with one of such plates holding the last segment before the separation and the other, placed above the last segment, maintains the flow of successive segments.

The method according to the invention is characterised in that the segment containing the loose material is measured out by volume or by weight.

Furthermore, the substance of the invention is an apparatus designed to put together the segments of a multi-segment continuous rod, comprising a carrier transferring the segments in order to form a segment train characterised by additionally comprising a unit feeding segments containing the loose material in a sheath, with the feeding unit having a seat designed to feed individual segments containing the loose material in the sheath synchronously to the movement of other segments on the conveyor.

The apparatus according to the invention is characterised by additionally comprising a filling unit designed to bring loose material into the sheath.

The apparatus according to the invention is characterised in that at least one conveyor is a drum conveyor used to place the segment containing the loose material between solid segments.

The apparatus according to the invention is characterised in that at least one conveyor is a belt conveyor used to place the segment containing the loose material among solid segments.

The apparatus according to the invention is characterised by additionally comprising a unit separating the segments containing the loose material from one another.

The apparatus according to the invention is characterised in that the separating unit comprises two separating plates, with one of such plates holding the last segment before the separation and the second, placed above the last segment, maintaining the flow of successive segments.

Owing to the method according to the invention, it is possible to increase the efficiency of manufacturing of multi-segment rods and improve the quality of manufactured rods. Moreover, an additional effect in the form of reduced contamination of the rod manufacturing machine with the loose material has been achieved. The loose material does not find its way between other segments and the wrapping material.

The object of the invention was shown in detail in a preferred embodiment in a drawing in which:

Fig. 1 shows an example of a multi-segment rod manufactured according to the methods known in the prior art;

Fig. 2 shows a multi-segment continuous rod according to the invention;

Fig. 3 shows an apparatus for the production of segments according to the invention;

Fig. 4 shows an apparatus designed to bring segments according to the invention into a train of segments of the multi-segment continuous rod;

Fig. 5 shows another embodiment of the apparatus designed to bring segments according to the invention into a train of segments of the multi-segment continuous rod.

Fig. 1 shows a multi-segment continuous rod 1 known from the prior art, used in the tobacco industry's articles, whereas such continuous rod contains loose material 2, usually granulated material, which in a closed space (a pocket) constitutes the functional segment S. A frequently used loose material is the activated charcoal whose task is to absorb substances which are harmful to the smoker. The space occupied by the segment S is limited by solid segments S1 , in particular the front surfaces of the segments S1 , whereas the segments S1 are made of a filter material in the solid form, for example made of acetate. The alternately situated segments S and S1 form a segment train wrapped in a common paper wrapper 3, whereas the granulated material is placed in the space between the segments S1 after previous placing of the segments S1 in the paper wrapper. The paper wrapper 4 constitutes a cylindrical sidewall of the space occupied by the segments S which together with the front surfaces of the segments S1 forms the pocket for the loose material. In industrial processes, at the place at which the pocket is formed the solid segments move with considerable linear speeds. Due to the drawbacks, identified in the prior art, of known solutions used to fill the spaces in a train of segments with a loose material, each of the spaces of the segment S is filled to a slightly different degree because it is difficult to precisely control the amount of supplied material at the considerable speed of moving segments, irrespective of the fact whether the loose material is supplied by gravity or by pressure.

The multi-segment continuous rod 10 shown in Fig. 2 is free of the drawbacks known form the prior art. The train of segments with any length may be put together on any carrier, whereas the carrier may be a depression in the circumferential surface of a drum conveyor or the surface of a belt conveyor, whereas the surface of the conveyor in the time in which the train of segments is put together may be formed in the cross section in the shape of the letter U. According to the invention, the segment S2 containing the loose material 2 (granulated material or powder) is made outside the place at which the segment train is put together. The segment S2 has a sheath 4 into which the loose material 2 is brought. Due to the fact that the loose material is brought into the sheath 4 outside the place at which the segments are put together, the segment S2 may be placed in the train as a separate pre-shaped segment with a form which is independent of the adjacent segments in the train.

The segment S2 has the sheath 4 forming a sidewall of the segment, whereas such sheath may be open at both sides or open at one side. The sheath 4 which is open at one side, at the closed side is made of a material which is permeable to gases which may be the same material of which the sidewall of the sheath is made, or the side closure may be made of a different material which is permeable to gases, e.g. a mesh of plastic. The lateral closure of the segment facilitates the transport of segments S2 filled with a material which spills out to a considerable degree, that is such segments which have a low tendency to maintain the shape. The material for the sheath 4 may be supplied in the cylindrical form, or it may have the shape of a polygon and may be supplied in the folded form, to be unfolded before placing the loose material in it. With the use of an adequately deformable material, it is possible to change the shape from polygonal to cylindrical, generally close to a cylindrical shape.

Some loose materials have the ability to remain in the mass, it was observed that after filling a sheath being open at both sides they do not spill out, for example cut tobacco, generally the materials being the result of tobacco processing.

Other loose materials with a lower ability to remain in the mass require the closure of the sheath with an additional holding material preventing the spilling. However, it was noticed that even in case of spilling materials it was possible to bring a segment to the place at which it was to be placed in the multi-segment continuous rod so that the spilling was reduced or even eliminated without the need of lateral closure of the segment. For this purpose, for example guide units for example made of holding metal plates which prevent the spilling of loose material during the transport of the segment are used. Namely, the open sidewalls of the segment move on lateral guides, and the distance between the side of the segment and the guide is so small that it prevents the loose material from spilling out.

In case of materials which spill out to a considerable degree it is possible to introduce a number of additional elements protecting the material from getting out of the sheath. Apart from the segment closures at both sides mentioned above and the holding guides at both sides, for example in the form of metal plates preventing the loose material from spilling out, an alternative method to solve the problem of spilling is a momentary change of physical properties of the loose material, for example by moistening it.

The sheath 4 of the segment S2 is preferably made of a material selected from a group comprising: paper, cardboard, plastics, polymer material, film of a material of plant origin for example a maize flour based material, the material may have a compact structure or may have an openwork structure or may be a mesh with a size selected according to the size of granulated material or powder of the filter material. On the other hand, the loose material is preferably a material of a group comprising: activated charcoal, tobacco processing products, polymer material, and material of plant origin for example a maize flour based material.

The material holding the loose material 2 inside the sheath 4, of which the lateral closing elements are made, is preferably selected form a group comprising: paper of porous structure, mesh, fabric, materials permeable to gases in the form of honeycomb.

The loose material placed inside the sheath 4 may be measured out by weight or by volume. In case of loose materials in the form of granulated materials with a considerable diameter it is possible to measure out granulated material by the piece.

Fig. 3 shows an apparatus for the production of segments according to the invention. The apparatus 20 for the production of segments comprises three principal sub-assemblies, an empty sheath store 26, a filling unit 22 and a finished segment store 27. The empty sheath store 26 has the task to store the empty sheaths 4 and to deliver them to the filling unit 22. The store 26 of Fig. 3 has the form of a vertical channel limited by lateral guides 21. From the empty sheath store 26 the sheaths 4 are delivered to the filling unit 22. Empty sheaths are inserted into the filling seat 5 of the filling unit 22 by means of a unit of synchronously working separating plates or slide valves 6, 6'. By sliding, the slide valve 6 controls the insertion of empty sheaths into the filling seat 5. By sliding, the slide valve 6' controls the removal of the sheaths 4 filled with the loose material 2 from the filing seat. The filling unit 22 has the task to fill the empty sheath 4 with the loose material 2. Principal elements of the filling unit 22 are the filling seats 5, the loose material 2 container 8 which feeds the loose material 2 to the metering chamber 23 in which the piston 9 moves. The size of the metering chamber 23 matches the volume of the sheath 4. The loose material 2 from the container 8 is inserted into the metering chamber 23 by gravity or with the aid of additional inserting means (not shown). The movement of the piston 9 pushes the loose material inside the empty sheath 4 situated in the filling seat 5. Fig. 3 shows the unit 22 filling the sheaths 4 which are open at both sides, which is why the filling seat 5 comprises a limiting element 7 whose task is to limit the spilling of the loose material 2 out of the sheath 4. The limiting element 7 is preferably permeable to gases so that an unfavourable compression of gases during the movement of the loose material 2 towards the inside of the sheath 4 is avoided. Finished segments S2 are removed from the filling seat to the finished segment store 27 which in the embodiment shown in Fig. 3 has the form of lateral guides 11 , 12, 13. The right-sided guide is a divided guide and consists of an upper element 12 and a lower element 13. The division of the guide is a consequence of the use of the slide valves 14, 14' controlling the delivery of segments to the placing unit or directly to the stream of solid segments. The area between the slide valves 14, 14' constitutes the seat of the store 27 from which the segment S2 is supplied to the segment train or to the intermediate unit.

In addition, an apparatus for the production of segments according to the invention may be provided with a unit for closing material application, where such material stops the spilling of the loose material and facilitates the transport of finished segments among the production line equipment or even among individual manufacturing plants.

Fig. 4 shows an apparatus designed to bring the segments S2 into the segment train ST in the first embodiment. The apparatus has a transferring element designed to transfer the segment S2 in the form of a wheel 17 having seats 16, the wheel 17 being situated above the carrier in the form of the belt 19 on which the segment train ST is situated. The segment S2 is delivered individually to the seat 16 from the segment S2 feeding unit. Successive segments S2 are placed in successive seats 16. When rotating, the wheel 17 transfers the segments S2 to the segment train ST. After the transfer of the segment S2 so that it is situated directly above the gap between the segments S1 and S3, the segment S2 is placed in the gap between the segments S1 and S3 by means of known, not shown mechanisms comprising such element as lug, ejector, pusher, cam etc. The rotational speed of the wheel 17 is synchronised with the speed of the carrier 19 in order to facilitate the placement of the segment S2 between other segments.

Figs. 3 and 4 show the first embodiment of the invention concerning the apparatus for the manufacture of segments of multi-segment articles of the tobacco industry. The apparatus according to the first embodiment is characterised by comprising: an empty sheath store (container) 26 for shaped sheaths 4 forming a sidewall of the segment S2, a loose material 2 container unit 8 designed to feed the loose material to the sheath 4, filling means 22 designed to bring the loose material 2 into the sheath 4.

Furthermore, this apparatus comprises a filling seat 5 receiving the sheaths 4, a metering chamber 23 and a piston 9 bringing the loose material 2 from the metering chamber 23 into the sheath 4.

Optionally, the apparatus may comprise means designed to measure out the loose material as well as a typical sheath closing unit applying a material holding the loose material at the open end pieces, whereas the joining of round fragments of the material holding the loose material may take place by gluing or welding.

During the production of segments, the successive segments S2 containing the loose material 2 are separated from one another by means of a separating unit 24, with the separating unit 24 comprising two separating plates (slide valves) 14, 14', where one of such plates 14' holds the last segment S2 before the separation, and the second plate 14, disposed above the last segment, maintains the flow of successive segments S2. The guides 11 , 12 and 13 are designed to keep the loose material inside the sheaths 4.

When putting together the segments of the multi-segment continuous rod, a previously made segment S2 of the multi-segment article of the tobacco industry comprising the shaped sheath 4 forming a sidewall of the segment S2 and the loose material 2 placed inside the sheath 4 are received. It should be noted that the segment S2 is made outside the carrier 19 on which the segments on the multi-segment article are put together. The segment S2 containing the loose material 2 in the cylindrical sheath 4 is placed between the segments S1 and S3 in the segment train ST on the carrier 19 on which the segments of the multi-segment article are put together, whereas the wrapping material may be placed on the carrier. The next stage consists in that the formed segment train ST' is wrapped with the common wrapping material 3 so that a multi-segment continuous rod 10 is formed, afterwards the formed multi-segment continuous rod 10 is cut into individual multi-segment rods, whereas the individual multi-segment rod may be cut into individual multi-segment fragments to be applied to cigarettes as multi-segment filters.

A segment containing the loose material 2 may be placed between the segments on a drum or belt conveyor.

In the method according to the invention the loose material 2 is measured out by volume or by weight.

Fig. 5 shows the second embodiment of an apparatus designed to put together the segments of a multi- segment continuous rod. The apparatus according to the second embodiment differs from the first embodiment in that the process of placing of the segments S2 according to the invention takes place linearly without the use of a delivery wheel. The second embodiment feeds a linear stream of segments according to the invention perpendicular to the stream ST of solid segments S1 , S3. The segments S2 are guided among the guides 11 , 12 and 13 which are designed to hold the loose material in the sheaths 4. If the sheaths 4 have glued or welded elements closing the loose material inside the sheaths 4, then the guides 11 , 12 and 13 are adapted to the shape and the dimensions of the segments S2. The segments S2 are placed individually between the segments S1 and S3 by means of the slide valves 14, 14' similar to the first embodiment. The area between the slide valves 14, 14' constitutes the seat of the feeding unit 25 from which the segment S2 is fed to the segment train. Successive phases of placement of the segment S2 in the segment train ST are shown in Figs. 5a, 5b, 5c and 5d. During the placement of the segment S2 between the segments S1 and S3 the speed of the unit 25 feeding the segments S2 is synchronised with the speed of the segment train ST. After feeding one segment S2, the feeding unit 25 withdraws in order to feed another segment S2 into another gap. The formed segment train ST' may be directly fed to be wrapped in the wrapping material. The solution according to the second embodiment may be used for smaller linear speeds.

Combining the advantages resulting from the use of a loose material, i.e. granulated material or powder, with the ease and speed of positioning of solid segments, various problems which in the prior art made it impossible to widely use loose materials as component materials of multi-segment articles have been solved.

Claims

Patent claims

1. A segment of a multi-segment article of the tobacco industry characterised by comprising

a sheath (4) forming a sidewall of a segment (S2), and

a loose material (2) placed inside the sheath (4), whereas

the segment is made outside a carrier on which the segments of the multi-segment articles are put together.

2. The segment as in claim 1 , characterised in that the sheath (4) forming the sidewall of the segment (S2) is open at both sides.

3. The segment as in claim 1 , characterised in that the sheath (4) forming the sidewall of the segment (S2) is open at one side, while at the closed side it is made of a material which is permeable to gases.

4. The segment as in claim 2 or 3, characterised in that the sheath (4) forming the sidewall of the segment (S2) is cylindrical.

5. The segment as in any of the preceding claims 1 to 4, characterised in that the material of which the sheath (4) was made was selected from a group comprising: paper, cardboard, plastics, polymer material, film of a material of plant origin.

6. The segment as in any of the preceding claims 1 to 5, characterised in that the loose material (2) was selected from a group comprising: activated charcoal, tobacco, tobacco processing products, polymer material, and material of plant origin.

7. The segment as in any of the preceding claims 1 to 6, characterised in that the open end pieces of the sheath are protected by a material holding the loose material (2) inside the sheath (4).

8. The segment as in any of the preceding claims 1 to 7, characterised in that the material holding the loose material 2 inside the sheath 4 was selected from a group comprising: paper of porous structure, mesh, fabric, materials permeable to gases in the form of honeycomb.

9 The segment as in any of the preceding claims 1 to 8, characterised in that the loose material (2) is measured out by weight or by volume.

10. An apparatus for the manufacture of segments (S2) of multi-segment articles of tobacco industry characterised by comprising:

a container (26) for sheaths (4) forming a sidewall of the segment (S2), a loose material (2) container unit (8) designed to feed the loose material (2) to a sheath (4) ,

filling means (22) designed to bring the loose material (2) into the sheath (4).

11. The apparatus as in claim 10, characterised in that the filling means (22) comprise a seat (5) receiving the sheaths (4), a metering chamber (23) and a piston (9) bringing the loose material (2) from the metering chamber (23) into the sheath (4).

12. The apparatus as in claim 10 or 11 , characterised by comprising a sheath (4) closing unit applying a material holding the loose material (2) at the open end pieces.

13. The apparatus according to any of the claims 10 to 12, characterised by additionally comprising loose material measuring means.

14. A method of putting together of segments of a multi-segment continuous rod characterised in that

a previously made segment (S2) of a multi-segment article of the tobacco industry comprising

a shaped sheath (4) forming a sidewall of the segment (S2), and

a loose material (2) placed inside the sheath (4) are received, whereas the segment is made outside the carrier (19) on which the segments of the multi-segment article are put together,

the segment (S2) containing the loose material (2) in the sheath (4) is placed between the segments (S1 , S3) on the carrier (19) on which the segments of the multi-segment article are put together.

15. The method as in claim 14, characterised in that afterwards

the formed segment train is wrapped in a common wrapping material (3) so that a multi- segment continuous rod (10) is formed, after which

the formed multi-segment continuous rod (10) is cut into individual multi-segment rods, whereas the individual multi-segment rod may be cut into individual multi-segment filters.

16. The method as in claim 14 or 15, characterised in that the segment (S2) containing the loose material (2) is placed between the segments on a drum conveyor.

17. The method as in claim 14 or 15, characterised in that the segment (S2) containing the loose material (2) is placed between the segments on a belt conveyor (19).

18. The method as in any of the claims 14 to 17, characterised in that the segments (S2) containing the loose material (2) are separated from one another by means of a separating unit (24).

19. The method as in claim 18, characterised in that the segments (S2) containing the loose material (2) are separated from one another by means of the separating unit (24) comprising two separating plates (14, 14'), where one of such plates (14') holds the last segment (S2) before the separation, and the second plate (14), placed above the last segment (S2), maintains the flow of successive segments (S2).

20. The method as in any of the claims 14 to 19, characterised in that the loose material (2) is

measured out by volume or by weight.

21. An apparatus designed to put together the segments of a multi-segment continuous rod

comprising

a carrier (19) transferring the segments in order to form a segment train, characterised by additionally

comprising a unit (25, 27, 28) feeding the segments (S2) containing a loose material (2) in a sheath (4), whereas

the segment (S2) feeding unit (25, 27, 28) has seats (16) designed to feed individual segments (S2) containing the loose material in the sheath synchronously to the movement of other segments (S1, S3) on the carrier (19).

22. The apparatus as in claim 21 , characterised by additionally comprising a filling unit (22) designed to bring the loose material (2) into the sheath (4).

23. The apparatus as in claim 21 or 22, characterised in that the carrier (19) is a drum conveyor designed to place the segment (S2) containing the loose material (2) between the solid segments (S1 , S3).

24. The apparatus as in claim 21 or 22, characterised in that the carrier (19) is a belt conveyor designed to place the segment (S2) containing the loose material (2) between the solid segments (S1 , S3).

25. The apparatus as in any of the claims 21 to 24, characterised by additionally comprising a unit (24) separating the segments (S2) containing the loose material (2) from one another.

25. The apparatus as in claim 24, characterised in that the separating unit (24) comprises two separating plates (14, 14'), where one such plate (14') holds the last segment (S2) before the separation, and the second plate (14), placed above the last segment (S2), maintains the flow of successive segments (S2).