Patent Publication Number: US-2022218017-A1

Title: Machine and method for making a sub-unit of a smoking article

Description:
TECHNICAL FIELD 
     This invention addresses the technical field of the production of articles of the tobacco industry. 
     This invention relates in particular to a machine and a method for making a sub-unit of a smoking article, which may be for example a smoking article of the type configured to generate aerosol by heating, preferably without burning, or an electronic cigarette. 
     In this context, in order to be able to ensure the quality of the finished product, it is very important to guarantee that the active material—that is, the material that generates the aerosol—is correctly contained and retained both during the production process and during use of the article. 
     BACKGROUND ART 
     Prior art production methods involve making a smoking article composed of a rod-shaped body (for example a filter or a heating element) and a tube made of wrapping material which is then filled with the aerosol-generating element. 
     However, that solution is not well suited to guaranteeing the integrity of the article, in particular because it does not allow guaranteed correct retaining of the aerosol-generating element, that is to say, the active portion of the smoking article, inside the tubular wrapping material when a smoker inhales. 
     That means that during use of the smoking article, the aerosol generating element could come out of its sub-unit and find its way into the adjacent ones, thus negatively affecting the operation of the product. 
     Indeed, the effect of the smoker puffing at the smoking article could have the undesirable result of causing the aerosol generating element or any of the other materials making up the smoking article to come out of the sub-unit. 
     AIM OF THE INVENTION 
     In this context, the technical purpose which forms the basis of this invention is to propose a machine and a method for making a sub-unit of a smoking article which overcomes at least some of the above-mentioned disadvantages of the prior art. 
     In particular, the aim of this invention is to provide a machine and a method for making a sub-unit of a smoking article capable of optimising the production process by simultaneously improving the quality and the stability of the finished product which can be made. 
     The technical purpose specified and the aims indicated are substantially achieved by a machine and a method for making a sub-unit of a smoking article, comprising the technical features set out in one or more of the appended claims. 
     Accordingly this invention provides a machine for making sub-units of smoking articles which comprises a conveyor, a feed unit, cutting means and at least one rotary applicator. 
     The conveyor is configured to feed a succession of tubular segments of the tobacco industry. 
     The feed unit is configured to feed and convey a continuous web. 
     The cutting means are configured to separate a succession of closing elements from a front end of the continuous web. 
     The at least one rotary applicator is operatively associated with the conveyor and is configured to pick up the succession of closing elements and to apply them, preferably by gluing, to an application end of a respective tubular segment, in such a way as to form closing walls to at least partly close the application ends. 
     Preferably, the cutting means are configured to separate from the continuous web closing elements having a size such that they partly cover the application end. 
     Alternatively, the cutting means are configured to separate from the continuous web closing elements having a size such that they completely cover the application end. 
     Advantageously, the machine described herein allows application of the closing elements on the tubular segments, in such a way as to make sub-units having suitable closing walls in at least one of their ends 
     That device prevents material from accidentally going through the closed end of the segment itself. 
     This invention also relates to a method for making a sub-unit of a smoking article which comprises the steps of:
         preparing a tubular segment of the tobacco industry, being internally provided with a through duct terminating with end openings of the tubular segment;   applying a closing element on at least one application end of the tubular segment by means of a rotary applicator, in such a way as to form a closing wall to at least partly close that application end.       

     Advantageously, the method proposed herein supplies a rapid and efficient procedure for applying a closing wall to a tubular segment, in such a way as to make a sub-unit capable of guaranteeing correct retaining of the filling material of the smoking article into which it will be inserted. 
     This invention also relates to a smoking article which comprises an aerosol-generating segment, a filtering segment and at least one spacer tube interposed between the two segments. 
     In particular, the spacer tube has one end at least partly closed by a closing element applied to an application end of it to at least partly close that application end. 
     In particular, the closing element is interposed between the spacer tube and one of either the aerosol-generating segment or the filtering segment. 
     Preferably, the spacer tube directly abuts against the aerosol-generating segment and/or against the filtering segment. 
     Preferably, the smoking article comprises an additional segment, in particular a tubular cooling segment. 
     In particular, the additional segment is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment. 
     Preferably, the spacer tube abuts directly against the additional segment in such a way that the closing element is directly interposed between the spacer tube and the additional segment. 
     Preferably, the closing element is made of material that is porous and/or has a plurality of holes or perforations suitable for increasing the air and/or gas permeability of the closing wall. 
     Preferably, the closing element is made of metallic material, even more preferably the closing element is made of aluminium. 
     Preferably the closing element is made of fire-resistant material. 
     Advantageously, the particular structural configuration of the smoking article guarantees, by the presence of the closing wall interposed between adjacent segments, that the filling material is retained correctly, preventing it from migrating inside the smoking article and preferably also from coming out of it. 
     Also an object of this invention is a method for making a smoking article, comprising the following steps:
         preparing a filtering segment   preparing an aerosol-generating segment;   preparing a spacer tube having one end at least partly closed with a closing element applied in an application end of it, to at least partly close that application end,   aligning along a predominant line of extension the filtering segment, the aerosol-generating segment and the spacer tube in such a way that the closing element is interposed between the spacer tube and one of either the aerosol-generating segment or the filtering segment.       

     Preferably, the method further comprises the steps of:
         preparing an additional segment, in particular a cooling segment which is preferably tubular.   interposing the additional segment between the spacer tube and one of either the aerosol-generating segment or the filtering segment, directly abutting the spacer tube against the additional segment in such a way that the closing element is directly interposed between the two.       

     Advantageously, the method described herein allows a smoking article to be made which has a closing wall to prevent the passage of the filling material of the article itself from one portion of it to another. 
     The dependent claims, which are incorporated herein by reference, correspond to different embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of this invention are more apparent in the indicative, non-limiting description below, with reference to a preferred, but non-exclusive embodiment of a machine and a method for making a sub-unit of a smoking article, as illustrated in the accompanying drawings in which: 
         FIG. 1  schematically illustrates the main components of a machine according to this invention; 
         FIGS. 2 to 6  show in detail different possible embodiments of several of the components of the machine of  FIG. 1 ; 
         FIGS. 7 and 8  show sub-units made by the machine and according to the method disclosed; 
         FIG. 9  is a cross-section of a smoking article. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
     In the accompanying figures the reference number  10  generically indicates a machine for making sub-units  20  of smoking articles, hereinafter in this description indicated simply as the machine  10 . 
     The machine  10  comprises a conveyor  11 , a feed unit  12 , cutting means  13  and at least one rotary applicator  14 . 
     The conveyor  11  is configured to feed a succession of tubular segments  21  of the tobacco industry. 
     For example, the conveyor  11  may be made in the form of a conveyor drum, a conveyor belt or other conveying devices having appropriate seats suitable for retaining the tubular segments. 
     In particular, each tubular segment  21  has an axis of predominant extension, around which the tubular segment  21  extends and preferably defining an axial axis of symmetry of the tubular segment  21  itself. 
     Moreover, each tubular segment  21  is internally provided with a through duct, which terminates with respective openings at opposite ends of the tubular segment  21 . At each of the end openings, each tubular segment  21  has an annular front surface delimiting the above-mentioned through duct. Those front surfaces lie in respective planes which are parallel to each other and perpendicular to the above-mentioned axis of predominant extension. 
     In other words, the interior of the tubular segment  21  defines a duct, which also acts as a containment chamber for containing a filling material of the tobacco industry and which terminates in the open ends of the tubular segment  21  itself. 
     By way of a non-limiting example, the through duct may therefore contain a filling material such as an aerosol-generating material, tobacco pellets, tobacco which is loose or in another form, flavouring material (for example micro-capsules containing a flavouring liquid) or a filtering material (activated carbon, silica gel or others known in the reference sector) or even a material with cooling effect (such as PLA pellets). 
     The feed unit  12  is configured to feed a continuous web “N”, preferably by unwinding a reel housed on a suitable support, and to convey it, for example by means of guide elements such as one or more idle or motor-driven rollers. 
     The cutting means  13  are operatively associated with the feed means  12  to engage the continuous web “N” along its conveying path and are configured to separate a succession of closing elements  22  from a front end of that continuous web “N”. 
     In particular, the cutting means  13  are configured to make a cut across the full width of the continuous web “N”. 
     Preferably, the cutting means  13  comprise a pair of cutting drums which operate in conjunction with each other to separate a succession of closing elements from a front end of the continuous web “N”. 
     In particular, the pair of cutting drums comprises a first drum  13   a  whose surface is provided with a succession of cutting blades configured to engage the continuous web “N” to separate the succession of closing elements therefrom. 
     The pair of cutting drums also comprises a second drum  13   b  configured to convey the continuous web “N” until it engages the cutting blades of the first drum. 
     The second drum  13   b  is also configured to radially space the individual closing elements after they have been separated from the continuous web “N”. 
     The applicator  14  is in particular a rotary applicator operatively associated with the conveyor  11  and is configured to pick up the succession of closing elements, in particular from the cutting means  13 , and to apply each closing element  22  to an application end of a respective tubular segment  21 . 
     In particular, the applicator  14  comprises an applicator wheel which has a plurality of seats disposed radially and set equal distances apart along its circumference. 
     Those seats are moved, by the rotation of the applicator wheel along a circular path in which they sequentially engage the cutting means  13 , receiving from them and retaining a succession of closing elements  22 , and then the conveyor  11 , for application of the closing elements on respective application ends of the tubular segments  21 . 
     According to the invention, the applicator  14  is configured and/or disposed to release each closing element  22  on a front wall of a respective closing element  22 . In particular, the applicator  14  is configured and/or disposed to move each closing element  22  along a trajectory having at least one component parallel to the axis of predominant extension of the respective tubular segment  21  on which the closing element  22  must be applied. 
     According to one embodiment, schematically shown in  FIG. 2 , the applicator wheel has an axis of rotation “R” perpendicular to the axis of predominant extension of the tubular segments as they are conveyed by the conveyor  11 . That configuration and positioning of the applicator wheel  14  defines a circular conveying trajectory which is at a tangent to the trajectory followed by the front surface of the respective tubular segment  21  on which the closing element  22  must be applied. 
     Alternatively, as is schematically shown in  FIGS. 3 to 6 , the applicator wheel has an axis of rotation “R” which is inclined relative to an axis of predominant extension of the tubular segments  21  when these are being carried by the conveyor, being preferably inclined at an angle between 30° and 60° and still more preferably, at an angle of 45°. That configuration and positioning of the applicator wheel  14  defines a circular conveying trajectory which is in any case at a tangent to the trajectory followed by the front surface of the respective tubular segment  21  on which the closing element  22  must be applied. 
     Therefore, according to the invention the applicator  14  causes a gradual movement of the closing elements  22  towards the respective tubular segments  21  in such a way as to release the closing elements  22  so that they rest on the front surface of the respective tubular segment  21 . 
     Therefore, by applying the closing element  22  a closing wall is created which at least partly closes the application end on which that closing element  22  has been placed. 
     In particular, the closing wall provides a barrier which prevents any filling material of the smoking article  30  into which the sub-unit  20  will be placed from passing through the application end of the tubular segment  21 . 
     At the same time, the closing wall must be such as to allow the passage of air and/or gas and/or aerosol through the end of the sub-unit  20 , in particular in the direction of a smoker during use of the smoking article  30  into which the sub-unit  20  has been inserted. 
     According to a first possible embodiment, the closing element  22  has an overall size such that it completely covers the application end. 
     Alternatively, the closing element  22  has an overall size such that it only partly covers the application end. 
     If the closing wall completely covers the application end of the tubular segment  21 , in order to guarantee the correct inflow of air and/or gases and/or aerosol through the sub-unit  20 , the closing element  22  is made of material which is porous and/or has a plurality of holes or perforations suitable for increasing the air or gas permeability of the closing wall. 
     In other words, if the closing wall is such that it completely closes off access to the duct defined inside the tubular segment  21 , the closing element  22  is made in such a way as to in any case allow the passage of air and/or gas and/or aerosol either because it is made of porous material and/or because it has suitable openings. 
     For that purpose, the machine  10  comprises perforating means, operating in particular on the continuous web “N” to make holes or perforations configured to allow air or gas to pass through them. 
     Preferably, the perforating means comprise at least one laser. 
     In contrast, if the closing wall only partly covers the application end of the tubular segment  21 , the correct inflow of air and/or gas and/or aerosol through the sub-unit  20  is guaranteed by those portions of the application end which remain uncovered, therefore the closing element  22  may even be made of material which is impermeable to air. 
     It is also possible for the closing element  22  to in any case be made of material which is porous or which has a plurality of holes or perforations suitable for increasing the air and/or gas permeability of the closing wall, even if the closing element  22  only partly closes the application end. 
     In particular, the closing element  22  may be made of metallic material, for example of aluminium. 
     Preferably, the closing element  22  is made of fire-resistant material. 
     In general, the machine  10  further comprises folding means, disposed downstream of the at least one applicator  14 , which are configured to fold against an external surface (that is to say, cylindrical) of the tubular segment  21  end or peripheral portions of the respective closing element  22  protruding beyond an external profile of the application end (that is to say protruding radially outwards from the above-mentioned annular front wall of the tubular segment  21 ). 
     The presence of the folding means, whose structure will be described in more detail below, therefore allows improved adhesion of the closing element  22  to the tubular segment  21 , by increasing their surface area of contact with each other. 
     Moreover, the folding means allow improvement of the structural integrity of the sub-unit  20  by removing any protruding portions of the closing element  22  which could strike further portions of semi-finished products or operating devices during any further operating steps which the sub-unit  20  must be subjected to. 
     Preferably, coupling of the closing element  22  to the respective tubular segment  21  is performed by gluing. 
     For that purpose, the machine  10  comprises a gumming device configured to apply an adhesive substance on the application end of the tubular segment  21  and/or on the closing element  22 . 
     In other words, the gumming device is operatively associated either with the conveyor  11  or with the feed unit  12  in order to apply respectively on the application end or on the continuous web “N” an adhesive substance which will subsequently allow the closing element  22  and the tubular segment  21  to be constrained to each other at the application end. 
     Preferably, the gumming device is configured to apply the adhesive substance only on the portion of the closing element  22  or of the tubular segment  21  intended to come into contact respectively with the application end or with the closing element  22 . 
     In other words, the adhesive layer is applied according to a pattern which traces the profile where the closing element  22  and the application end of the tubular segment  21  are superposed, in contrast leaving free the part of the closing element  22  which is directly facing the duct defined by the tubular segment  21 . 
     The machine  10  further comprises detecting means configured to check the position of the closing element  22  relative to the application end. 
     By way of example and without limiting the scope of the invention, the detecting means may comprise optical sensors such as video cameras or acoustic sensors such as ultrasonic sensors. 
     According to one particular embodiment, the machine  10  may comprise a pair of rotary applicators  14  configured to apply respective successions of closing elements  22  on respective application ends of each tubular segment  21 . 
     According to one particular aspect of this invention, the conveyor  11  is configured to feed a succession of double-length tubular segments  21  of the tobacco industry. 
     The expression double-length tubular segment  21  denotes a tubular segment  21  whose length is such that the tubular segment can be divided into two distinct parts of equal length suitable for making two respective single-length tubular segments  21  of a smoking article  30 . 
     In other words, the double-length tubular segment  21  is suitable to be divided into two distinct parts along its centre line “M” to make two distinct tubular segments  21  each usable for making a smoking article  30 . 
     According to that embodiment, the machine  10  comprises a pair of rotary applicators  14 , which are configured to apply respective successions of closing elements  22  on respective opposite application ends of each double-length tubular segment  21 . 
     Moreover, the machine  10  comprises separating means, for example rotary blades, which are disposed upstream or downstream of the pair of applicators  14 . 
     The separating means are configured to cut the double-length tubular segment  21  along a midplane, in particular to make a succession of pairs of tubular segments  21 , which are preferably identical in terms of structure and size. 
     In this context, the folding means are movable, in particular along a line perpendicular to the application end and are configured to engage portions of the closing elements  22  that protrude beyond an edge of the respective application ends. 
     Operatively, the movable folding means are disposed downstream of the pair of applicators  14  and/or of the separating means. 
     According to a further possible embodiment, the machine comprises the separating means, but they are disposed upstream of the pair of applicators  14  and the machine  10  further comprises retracting means  15 , which are disposed downstream of the separating means. 
     The retracting means  15  are configured to axially space the pair of tubular segments  21  resulting from the cutting, by the separating means, of the double-length tubular segments  21 . 
     In particular, the retracting means  15  are configured to separate the tubular segments  21  in such a way that each tubular segment  21  has a first end that is directed towards the other tubular segment  21  and that is spaced from it and a second end that is opposite to the first end. 
     According to this embodiment, the machine  10  comprises a pair of rotary applicators  14  which in this context are configured to apply respective successions of closing elements  22  on respective application ends of the pair of tubular segments  21 , wherein in particular the application ends are defined by the first ends of the tubular segments  21 . 
     The machine  10  therefore comprises axially fixed folding means, that is to say, not movable, which are disposed along a feed path of the pair of tubular segments  21 , in such a way as to be placed between the tubular segments  21  which define the pair of tubular segments  21 . Preferably, the folding means are mounted on the conveyor in such a way as to be facing the tubular segments  21  as they are conveyed. 
     In this context, the tubular segments  21  are associated with movable elements configured to axially shift the tubular segments  21  while they are being conveyed, so that the application end engages the folding means. 
     The fixed folding means are configured to fold against an external surface of the tubular segment  21  portions of the respective closing element  22  protruding beyond the edge of the application end. 
     The machine  10  also comprises movement means configured to axially move the pair of tubular segments towards each other in such a way as to engage the folding means. 
     According to a first aspect of that embodiment, the retracting means  15  comprise a retracting drum and the rotary applicators  14  are associated with it in order to apply the closing elements  22  to tubular segments  21  disposed on the retracting drum. 
     In particular, the retracting drum comprises a plurality of movable elements, which define respective retaining seats for the tubular segments  21 , and are longitudinally translatable relative to the axis of predominant extension of the tubular segments  21  which they convey in such a way as to space them out. 
     Alternatively, according to a further aspect of that embodiment, the retracting means  15  comprise a retracting drum and a pair of conveyor drums disposed side by side and spaced from each other. 
     The pair of conveyor drums is disposed downstream of the retracting drum to receive from it respective successions of tubular segments. 
     In this context, each rotary applicator  14  is associated with a respective conveyor drum to apply the closing elements  22  on tubular segments  21  disposed on the respective conveyor drum. 
     According to one particular embodiment, if the tubular segments  21  conveyed are of double length, the feed unit  12  is configured to feed a double-width continuous web “N”. 
     In this context, the machine  10  further comprises dividing means configured to cut the continuous web “N” along its line of predominant extension, in such a way as to operatively separate it into two single-width continuous webs “N” which will then be fed to respective cutting means  13 . 
     Advantageously, this invention achieves the preset aims and overcomes the disadvantages of the prior art by providing the user with a machine for making sub-units  20  of smoking articles  30  which allows making a succession of sub-units  20  which are each provided with a closing wall adapted to hold the filling material within the smoking article  30 , in particular after the finished product has been assembled. 
     This invention also relates to a method for making a sub-unit  20  of a smoking article  30 . 
     The method comprises preparing a tubular segment  21  of the tobacco industry, in particular a tubular segment  21  which is internally provided with a through duct terminating with end openings of the tubular segment  21 . 
     The method then comprises applying a closing element  22  on at least one application end of the tubular segment  21  by means of a rotary applicator  14 , thereby forming a closing wall, which at least partly closes the application end. 
     The step of applying the closing element  22  is carried out by applying the closing element  22  resting on the front wall of the respective tubular segment  21 , in particular on the annular front wall of the respective tubular segment  21 . 
     In particular, the applying step is carried out by moving the closing element  22  along a trajectory having at least one component parallel to the axial axis of symmetry of the respective tubular segment  21 . 
     That trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment  21  and is preferably circular. 
     In particular, the closing element  22  is made starting from a continuous web “N”, which is fed and made available for processing, for example by unwinding it from a suitable reel. 
     The continuous web “N” is then cut to make a succession of closing elements whose size and shape allow them to be applied on respective application ends. 
     The method described herein comprises in particular cutting the continuous web “N” across the full width of that continuous web “N”. 
     In this way, the whole of the continuous web “N” is substantially divided into a succession of closing elements  22  without the presence or creation of any waste or offcut portions or in any case without any portions of the continuous web “N” being left over which must be disposed of because they are not suitable for making a closing element  22  or part of one. 
     After they have been separated from the continuous web “N”, for example as already indicated by using the cutting means  13 , the closing elements  22  are picked up by the at least one rotary applicator  14  which will take them near to the tubular segments  21  and apply them at the respective application ends. 
     Preferably, the method comprises applying an adhesive substance on the application end of each tubular segment  21  and/or on the respective closing element  22  according to a specific, predetermined pattern. 
     Similarly to what has already been indicated relative to the operation of the gumming device of the machine  10 , the predetermined pattern is preferably a pattern which as accurately as possible traces the shape of the contact surface between the closing element  22  and the application end, in such a way that only the parts of them which must effectively be placed in contact with each other have a layer of adhesive on them. 
     In order to guarantee the correct inflow of air through the closing wall, the method further comprises increasing the air and/or gas permeability of the closing wall, preferably by making a plurality of holes or perforations in the continuous web “N” before cutting it. 
     That step intended to improve the permeability of the closing wall is carried out in particular if the material used to make the closing element  22  is impermeable to gases, but may also be carried out if the closing element  22  is made using a material which is naturally porous. 
     According to one particular aspect of this invention, the step of applying the closing element  22  is carried out by applying a pair of closing elements  22  simultaneously on each application end of the tubular segments  21 . According to a different aspect of this invention, the step of preparing a tubular segment  21  is carried out by preparing a double-length tubular segment  21  and the method further comprises carrying out a step of cutting the double-length tubular segment  21  along its midplane, in such a way as to obtain two tubular segments  21  of the tobacco industry. 
     The cutting step may be carried out upstream or downstream of application of the closing element  22 . 
     The cutting step is carried out in such a way that the tubular segments  21  have first ends abutted against each other at the midplane of the double-length tubular segment  21  from which they were created and second ends opposite the first ends. 
     According to a first possible embodiment, the closing element  22  is applied by applying a pair of closing elements  22  simultaneously on opposite application ends of the tubular segments  21  of the pair of tubular segments  21 , that is to say, those made by cutting a double-length tubular segment  21  into two distinct parts. 
     In particular, the application ends are defined by the second ends of the tubular segments  21 . 
     Alternatively, if cutting of the double-length tubular segment  21  precedes application of the closing elements  22 , the method may comprise axially spacing the pair of tubular segments  21  in such a way that their first ends are separate and facing each other. 
     In this situation, the step of applying the closing element  22  is carried out by applying a pair of closing elements  22  on facing application ends of the tubular segments  21  of the pair of tubular segments  21 , wherein the application ends are defined by the first ends. 
     Advantageously, this invention achieves the preset aims and overcomes the disadvantages of the prior art by providing the user with a method for making a sub-unit  20  of a smoking article  30  which can guarantee the structural integrity of the finished product in which the sub-unit  20  thus made will be included. 
     This invention also relates to a smoking article  30 , in particular a smoking article  30  which comprises sub-units  20  made using the machine and/or the method described above. 
     In particular, the smoking article  30  comprises an aerosol-generating segment  31 , a filtering segment  32  and a spacer tube. 
     The aerosol-generating segment  31  is preferably a tubular segment  21  into which an aerosol-generating material of the tobacco industry has been inserted. 
     The filtering segment  32  is preferably a tubular segment  21  made of material suitable for making a filter of the tobacco industry, or a tubular segment  21  filled with a filtering material of the tobacco industry. 
     The spacer tube is preferably an empty tubular segment  21  which is interposed between the aerosol-generating segment  31  and the filtering segment  32  in such a way as to separate them. 
     The spacer tube has one end at least partly closed by a closing element  22  applied in an application end of it to at least partly close that application end. 
     In particular, the closing element  22  is interposed between the spacer tube and at least one of either the aerosol-generating segment  31  or the filtering segment  32 . 
     Preferably, the spacer tube is directly abutted against the aerosol-generating segment  31  or against the filtering segment  32 . 
     According to one particular embodiment, shown in  FIG. 9 , the smoking article  30  comprises an additional segment  32  interposed between the spacer tube and the aerosol-generating segment  31  or interposed between the spacer tube and the filtering segment  32 . 
     Therefore, the spacer tube is directly abutting the additional segment  32  in such a way that the closing element  22  is directly interposed between the spacer tube and the additional segment  32 . 
     The additional segment  32  is preferably a tubular segment  21  filled with a cooling material of the tobacco industry. 
     Advantageously, the smoking article  30  described herein overcomes the disadvantages of the prior art, since the presence of the closing wall guarantees correct retaining of the aerosol-generating element inside the smoking article  30  preventing its unwanted escape or its inhalation by a smoker. 
     This invention also relates to a method for making a smoking article  30  which comprises preparing a filtering segment  32 , an aerosol-generating segment  31  and a spacer tube, all three preferably being made as indicated above. 
     In particular, the spacer tube is made using a tubular segment  21  which has one end at least partly closed by a closing element  22  applied on an application end of it to at least partly close the application end. 
     The method therefore comprises aligning along a predominant line of extension the filtering segment  32 , the aerosol-generating segment  31  and the spacer tube in such a way that the closing element  22  is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment  32 . 
     The method may also advantageously comprise a step of preparing an additional segment  32 , in particular a cooling segment which is preferably tubular. 
     During alignment of the various elements intended to form the smoking article  30 , the additional segment  32  is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment  32 . 
     In particular, the additional segment  32  is applied by abutting it directly against the spacer tube, in such a way that the closing element  22  is directly interposed between the spacer tube and the additional segment  32 . 
     Advantageously, the method described herein allows a smoking article  30  to be made which is particularly strong and of high quality, in which correct retaining (and consequent operation) of the filling material present inside it is guaranteed.