Machines and methods for manufacturing continuous tubular elements comprising fillers having spacer and / or filtration functions.

Abstract

This invention describes a machine (M) for manufacturing a continuous tubular element with filling by means of a roll, comprising first and second means (10, 30) for conveying respective continuous rolls (A, B), a forming station (20) configured to fold and / or deform the first continuous roll (A) into a shaped configuration, and a packaging station (50) in which a second continuous roll (B) is wound into a tubular shape around the first continuous forming roll (A) to obtain a continuous tubular element (T). At least one guide bar (23) is provided between the forming station (20) and the packaging station (50), around which the first continuous roll (A) is at least partially formed and / or guided.

Description

TECHNICAL FIELD

[0001] The present invention relates to a machine and a method for manufacturing a continuous tubular element from a web, in particular a paper-based material, formed by an outer tubular element and a filler obtained from the material in the form of a web.

[0002] More specifically, the continuous tubular element obtained according to the present invention can be used (after cutting) to form a series of segments (for example, filters, spacers or cooling devices) suitable for use in cigarettes or in aerosol generators, having spacing, filtering and / or cooling functions. BACKGROUND

[0003] The prior art hand-made cigarettes comprise a paper tube wrapped on a paper filler, which is in the form of an insert or is obtained using the same paper.

[0004] In the hand-made method for manufacturing the tube, a piece of outer paper is rolled into a tubular shape and then a filler insert, usually made of paper folded by hand, is placed inside the outer tube to partially fill the cavity defined by the outer tube.

[0005] These cigarettes, which are essentially made using ready-cut paper, are very easy to make by hand, but are not suitable for industrial production due to significant reasons of incompatibility with the production process, in particular because the processing of individual pieces of paper leads to a very low production rate. In fact, the individual processing of the insert is very time-consuming and, in addition, does not allow the final quality to be obtained repeatedly.

[0006] There are also prior art machines capable of producing a continuous tubular element comprising an outer tubular element and an internal filler obtained by shaping a web that is also continuous. In these machines, the internal web is subjected to a shaping operation for forming the insert, and then to a wrapping operation in which the outer web is wrapped around the insert to obtain the continuous tubular element.

[0007] Disadvantageously, the machines described above have problems in maintaining the shape of the internal web.

[0008] More specifically, during the wrapping of the outer web, the internal web undergoes a deformation (for example elastic return) of the profile obtained during shaping and / or unwanted folding.

[0009] This results in a continuous tubular element being obtained which does not have a precise cross-section and has an insert with a shape that does not correspond to the desired shape.

[0010] Moreover, in order to wrap the filling insert in the outer web, the prior art machines require that the filling insert completely fills the tubular element. In other words, after being gathered into a tubular shape, the cross section of the filling insert must be substantially the same as the continuous tubular element to be obtained. SUMMARY

[0011] In this context, the technical aim that forms the basis of the present application is to provide a machine and a method for manufacturing a continuous tubular element comprising a filling having spacing and / or filtering functions that overcome the above-mentioned prior art drawbacks.

[0012] More specifically, the aim of the present application is to provide a machine and a method for manufacturing a continuous tubular element comprising a filling having spacing and / or filtering functions that enable effective shape control of the final product.

[0013] The indicated technical aim and specific objects are substantially achieved by the machine and the method for manufacturing a continuous tubular element comprising a filling having spacing and / or filtering functions provided by the present application. BRIEF DESCRIPTION OF DRAWINGS

[0014] Further characteristics and advantages of the present application will become better apparent from the following detailed description, made with reference to the attached drawings, which illustrate a preferred, but not exclusive, embodiment of a machine and a method for manufacturing a continuous tubular element comprising a filling having spacing and / or filtering functions, in accordance with the present application, in which:

[0015] Figure 1 a schematic view of an embodiment of a machine for manufacturing a continuous tubular element from a web, in accordance with the present application, is shown;

[0016] Figure 2 is Figure 1 a schematic view of a variant embodiment of the machine of

[0017] Figures 3A-3I and Figure 3L a series of sectional views of the machine of Figure 1 and Figure 2 corresponding to the sectional lines shown in Figure 1 and / or Figure 2

[0018] Figure 4 a sectional view of a continuous tubular element obtained using the machine of Figure 2

[0019] Figure 4A a view of an enlarged detail of Figure 4

[0020] Figure 5 is Figure 1 or​​​Figure 2 perspective view of a detail of a machine for manufacturing a continuous tubular element T from two continuous webs of material;

[0021] Figure 6 a variant embodiment of a detail of a machine for manufacturing a continuous tubular element T from two continuous webs of material is shown; Figure 3E

[0022] Figure 7 a variant embodiment of a detail of a machine for manufacturing a continuous tubular element T from two continuous webs of material is shown. Figure 3A DETAILED DESCRIPTION

[0023] With reference to the attached drawings, in which: Figure 1 and 2 the reference "M" indicates a machine for manufacturing a continuous tubular element T from two continuous webs of material, according to the present application.

[0024] More specifically, the continuous tubular element T has an insert or filling made of a first continuous web A of suitable shape and a casing made of a second continuous web B wrapped on the previously shaped first continuous web A.

[0025] In the preferred embodiment, the first and second continuous webs A, B are made of paper material. However, the materials used can be different, without altering the inventive concept of the present application, they can even form a reduced thickness to have sufficient flexibility and curvature.

[0026] More specifically, for one or both of these continuous webs, different materials can be used (alone or mixed together) chosen from:

[0027] - cellulose-derived materials: for example cellulose acetate (tow);

[0028] - tobacco, recon or other plant-derived materials: for example wheat, corn, sugar cane, sugar beet, palm, papaya;

[0029] - polymeric plastic materials: for example polylactic acid (PLA), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET);

[0030] - biodegradable or compostable materials, for example the following bioplastics: Mater-Bi, PHAs (polyhydroxyalkanoates);

[0031] - metals: for example aluminum, stainless steel.

[0032] These materials can also include:

[0033] - plasticizers, solvents or humectants: for example triacetin (glyceryl triacetate), TEC (triethyl citrate), PEG 400 (low molecular weight polyethylene glycol);​​

[0034] - materials that in turn generate vapour, smoke or aerosol: for example water, glycerol, propylene glycol;

[0035] - natural or artificial flavours, for example menthol, fruit extracts, sugar, liquorice, liqueur flavourings, cocoa;

[0036] - materials with selective or adsorptive filtering action: for example activated carbon, silica gel;

[0037] - materials that help to join the components of the web by means of gluing: typically PVA, vegetable or animal-derived gums, starch, alginate, fats.

[0038] The materials mentioned above can be present simultaneously in the web of the tube or insert, or they can be chemically mixed or mechanically joined, for example by rolling, pressing, moulding, extruding, extruding, spraying, impregnating, sintering, gluing, interlacing powders or granules or filaments.

[0039] The web can be manufactured using similar methods to those used for preparing paper or reconstituted tobacco or plastic strips, or it can be a net, woven or non-woven web.

[0040] The machine M comprises first means 10 for transporting a first continuous web A configured to transport the first continuous web A along a first transport path, and second means 30 for transporting a second continuous web B configured to transport the second continuous web B along a second transport path. Preferably, the first and second transport means 10, 30 comprise, respectively, a respective reel that unwinds the continuous web A, B step by step and suitable guide rollers positioned along the transport path.

[0041] Figure 1 and 2 The features of most of the machines are identical, the difference being only in the fact that in the machine of Figure 1 the second continuous web B (defining the outer tubular element) maintains the same thickness from the respective reel to the end of the processing sequence and in particular adopts a single-layer configuration, while in the machine of Figure 2 the second continuous web B is subjected to a double fold along a respective longitudinal line to adopt a three-layer configuration (before the tubular shape).

[0042] To this end, the machine M comprises a folding unit 32 configured to fold the longitudinal strip of the second continuous web B about a respective longitudinal fold line, in particular to obtain a three-layer web with the side edges 2a, 2b having, respectively, a lowered zone 2a and a protruding joint zone 2b designed to facilitate the closure of the continuous tubular element T, as will be described in detail below (shown in Figure 4A ).

[0043] As mentioned above, the remaining part of the machine M is identical forFigure 1 and 2 The implementation method remains the same.

[0044] Machine M also includes a forming station 20, located on the first conveying path and configured to fold and / or deform the first continuous roll A into a forming configuration such that the first continuous roll A has a predetermined shape, particularly a three-dimensional and / or arcuate shape, in a cross-section transverse to the first conveying path. In the context of this invention, this specific shape does not limit the invention, as it can be any shape other than a circle. However, the accompanying drawings illustrate a non-limiting example embodiment.

[0045] More specifically, the forming station 20 includes a pair of preforming rollers 21, 22 whose outer contours are shaped to match each other (and thus geometrically join to form a slit with a preferably constant thickness) and define a gap between them for conveying a first continuous roll A through it to undergo a first permanent forming during rotation of the preforming rollers 21, 22.

[0046] exist Figure 3A In the embodiment shown, the preforming rollers 21 and 22 each have a profile shaped to match in a cross-section in a plane passing through their axes, including a substantially semi-circular segment between two straight segments.

[0047] In this embodiment, preforming rollers 21 and 22 perform a first permanent forming on the first continuous roll A, giving it a central portion 1a that is substantially an inverted U-shape in cross-section and two flat side portions 1b.

[0048] In another feasible implementation, the profiles of the preformed rollers 21, 22 can be formed by a series of arcuate segments, particularly splines, thereby forming shapes with different undulating segments.

[0049] In another feasible implementation, the profiles of the preformed rollers 21, 22 may be defined by straight segments alternating with arcuate portions or splines, thereby giving the first continuous roll A any shape.

[0050] According to Figure 7 In one different implementation, the outer contours of the preforming rollers 21, 22 are shaped to form slits with a non-constant thickness, i.e., having a protrusion-groove coupling in any case but not having a corresponding shape.

[0051] Downstream of the preforming rollers 21, 22, machine M includes a guide bar 23 around which the first continuous roll A is at least partially formed and / or guided. The guide bar 23 thus forms the core around which the preformed first continuous roll A is conveyed.

[0052] Advantageously, thanks to the presence of the guide bar 23, undesired deformations and / or folds of the first continuous web A are avoided, for example preventing the first continuous web A from deforming with respect to the shaped configuration obtained during the first shaping step.

[0053] The guide bar 23 is fixed at the rear, at or near the shaping station 20, to the frame of the machine M and extends longitudinally along the first conveying path.

[0054] Preferably, the guide bar 23 is formed as a bar-shaped body having a constant and solid cross section.

[0055] More preferably, the outer surface of the guide bar 23 is smooth, thus preventing the first continuous web A from wobbling during its sliding / shaping around the guide bar 23.

[0056] In the embodiment shown in the attached figures, the machine M comprises a single guide bar 23 having a substantially circular cross section, thus supporting the central portion la of the first continuous web A in the shaped configuration according to the first shaping.

[0057] According to a further embodiment of the pre-shaping rollers 21, 22 which take the first shaping on the first continuous web A, different from that shown in the attached figures, the machine M can comprise two or more guide bars 23, which are parallel and / or side by side or positioned in other ways and around which respective portions of the first continuous web A are at least partially formed and / or guided. In this case, the guide bars 23 can also have a cross section shape different from the circular one, in particular compatible with the mating shape generated by the pre-shaping rollers 21, 22.

[0058] Figure 6 A different arrangement of the different mating shapes generated by the guide bars 23 and the pre-shaping rollers 21, 22 is shown, in which two guide bars 23 are positioned parallel to each other to receive a first continuous web A substantially M-shaped.

[0059] Operationally, at the outlet of the pre-shaping rollers 21, 22, the first continuous web A is fixed on the guide bar 23 so that the pre-shaped (central) portion la of the first continuous web A placed on the guide bar 23 is at least partially wound around the guide bar.

[0060] Downstream of the pair of pre-shaping rollers 21, 22, to prevent the elastic return of the first continuous web A, the guide bar 23 can cooperate with a pair of guide elements 24, 25, for example in the form of metal bars or blocks formed extending parallel to the first conveying path.

[0061] As Figure 3BAs shown, the pair of guide elements 24, 25 delimit a gap through which the first continuous web A is passed, so that the longitudinal portions of the first continuous web A slide in substantially contact with the respective guide elements 24, 25.

[0062] The pair of guide elements 24, 25 thus defines a passage having a fixed width, thereby keeping the first continuous web A in the configuration it assumes after the first shaping, preventing the relative longitudinal portions from moving away from each other, for example due to the elastic return of the material of the first continuous web A.

[0063] Downstream of the pre-shaping rollers 21, 22 and, if present, of the guide elements 24, 25, the shaping station 20 also comprises a pair of shaping elements 26, 27, which are opposite each other and cooperate with the guide rod 23 to produce a second permanent shaping of the first continuous web A.

[0064] Preferably, the shaping elements 26, 27 comprise two fixed folding units defined by respective plates pivoted with respect to the frame of the machine M and having respective folding edges 26a, 27a converging and configured to move towards each other and permanently deform the respective longitudinal portions of the first continuous web A.

[0065] In Figure 3C In the embodiment shown, the shaping elements 26, 27 push the longitudinal portions of the first continuous web A towards each other so that the cross section of the first continuous web A assumes a substantially "omega" shape ("W). More specifically, as the first continuous web A passes between the shaping elements 26, 27, the flat side portions lb move towards each other, while the central portion la is bent so as to further wrap around the guide rod 23.

[0066] The shaping station 20 allows the continuous shaping of the first web A so that the first continuous web A, as it exits the work station, is shaped and ready to be inserted as an insert into the continuous tubular element T.

[0067] The shaping procedure that causes the first continuous web A to assume the shaped configuration is completed by the progressive folding and / or wrapping of the first continuous web A around the guide rod 23, with respective first and second steps of permanent shaping performed by the pre-shaping rollers 21, 22 and by the shaping elements 26, 27, respectively.

[0068] According to a variant embodiment, not shown, the shaping station 20 can be configured to perform only one of the pre-shaping and shaping operations described above, and therefore it can have only one of the respective shaping devices (more specifically, only one of the pair of pre-shaping rollers 21, 22 and of the pair of shaping elements 26, 27).

[0069] According to one embodiment (not shown), machine M may include sensors, such as optical sensors, located downstream of the preforming rollers 21, 22, for detecting any defects in the first continuous roll A and / or controlling the centering of the first continuous roll A downstream of the preforming rollers 21, 22. Essentially, the sensors are positioned to detect the first continuous roll A at one end of the guide bar 23. Machine M may also include a control unit that receives data measured by the sensors and, based on that data, controls the first conveying device 10 (via feedback).

[0070] like Figure 1 and 2 As shown, downstream of forming station 20, machine M includes an overlap area 40 in which first and second conveying paths combine with each other, such that portions of the first continuous roll A overlap with corresponding portions of the second continuous roll B.

[0071] Advantageously, this overlap occurs at the pre-adhesive area of ​​the first and / or second continuous rolls A, B. More specifically, it is preferable to apply adhesive to the second continuous roll B upstream of the overlap area.

[0072] In order to perform adhesive application on continuous rolls A and B, machine M includes a first adhesive application device 31 located upstream of the overlap area 40 along the first and / or second conveying path and configured to apply at least one longitudinal adhesive line 33 on the first and / or second continuous rolls A and B, respectively.

[0073] In the embodiment shown in the accompanying drawings, the first adhesive applicator 31 is positioned along the second conveying path to apply adhesive line 33 along the second continuous roll B.

[0074] The respective positions of the longitudinal adhesive lines 33 define corresponding adhesive areas for the portion of the first continuous roll A being bonded, such that the continuous tubular element T has separate contact lines and / or longitudinally extending surfaces (along the tubular element T) between the continuous rolls A and B. In other words, the number and / or arrangement of these longitudinal adhesive lines 33 are selected such that they correspond to corresponding separate overlapping areas between the two continuous rolls A and B. The term "discrete" refers to longitudinal lines or surfaces being separated from each other and / or spaced apart in the transverse direction.

[0075] Preferably, the first adhesive applicator 31 is adjustable at least in terms of its lateral position, particularly perpendicular to the second conveying path, to allow adjustment of the longitudinal adhesive line 33 in the event of a change in form.

[0076] In the embodiment shown in the drawings, the gluing device 31 comprises two dispensing nozzles and applies two longitudinal (and parallel) lines of glue 33 to the second continuous web B, thus defining two adhesive zones designed to receive the flat side 1 b of the first continuous web A shaped as an omega. In this case, the second continuous web B is in a flat configuration and is positioned below the first continuous web A, thus subsequently coming into contact with at least a portion of the flat side 1 b to define a separate contact surface between the webs A, B inside the continuous tubular web T. It should be understood that the number of nozzles of the gluing device 31 can vary depending on the number of longitudinal lines to be formed.

[0077] In another possible embodiment, not shown, the first gluing device 31 is preferably positioned upstream of the overlapping zone 40 and more preferably downstream of the forming station 20, so as to apply the longitudinal lines of glue 33 on the first continuous web A. More specifically, in this embodiment, the longitudinal lines of glue 33 are applied from below on a portion of the side 1 b of the first continuous web A, thus defining two adhesive zones designed to receive the respective portions of the second continuous web B. In order to prevent the first continuous web A from folding and / or deforming during the gluing step, thus altering the shaped configuration, the guide rod 23 also extends through the overlapping zone 40 so as to be interposed between the first continuous web A and the second continuous web B.

[0078] In the embodiment shown, there is a first pair of rollers 41, 42 positioned at the overlapping zone 40. More specifically, the lower roller 42 of the pair of rollers 41, 42 drives the guide belt 51 of the forming beam 50a of the packaging station 50, which will be described in detail below. The roller 42 has substantially smooth lateral surfaces. The second continuous web B is conveyed along the second conveying path until it is partially wound around the roller 42 (in contact with the guide belt 51 ) so as to be transferred from the overlapping zone 40 to the packaging station 50.

[0079] The upper roller 41 of the pair of rollers 41, 42 is shaped so as to allow the guide rod 23 and the shaped continuous web A to pass therethrough. Preferably, the upper roller 41 is made of rubber. More specifically, the outer lateral surface of the roller 41 is covered with rubber.

[0080] The first pair of rollers 41, 42 cooperates with the guide rod 23 to keep the first continuous web A in the shaped configuration, preventing the first web A from flattening during the gluing on the second continuous web B.

[0081] The machine M can also comprise a second pair of rollers 43, 44, which are located along the first conveying path upstream of the overlapping zone 40. The second pair of rollers 43, 44 acts on the preformed first continuous web A and keeps the longitudinal portion of the first continuous web A at least partially wound on the guide rod 23 while the guide rod 23 prevents the central portion la of the first continuous web A from flattening, thus helping to maintain the shaped configuration. Moreover, the second pair of rollers 43, 44 helps the first continuous web A to unroll and tension in the shaping zone 20.

[0082] Downstream of the overlapping zone 40, the machine M comprises a packaging station 50 in which the second continuous web B is wound on the preformed first continuous web A until it adopts a closed tubular shape, in particular having a circular cross section. More specifically, the overlapping zone 40 is located at the inlet of the packaging station 50 so that the second continuous web B can be located between the roller 42 and the above-mentioned guide and folding belt 51.

[0083] As shown in Figure 3E and 3F , the packaging station 50 comprises a shaping beam 50a configured to progressively wind the second continuous web B on the first continuous web A having a shaped configuration, preferably using the guide and folding belt 51 for the second continuous web B.

[0084] Advantageously, the guide rod 23 extends up to the packaging station 50, in particular until the second continuous web B is completely wound on the preformed first continuous web A.

[0085] The packaging station 50 also comprises a fixed shaping body 52 interposed between the guide rod 23 and the shaping beam 50a at least for a segment of the packaging station 50 to form a contact for folding the second continuous web B around the preformed first continuous web A. More specifically, the fixed shaping body 52 is configured to be positioned around the guide rod 23 with a predetermined overlapping angle, preferably greater than 180° and more preferably greater than 270°, as shown in Figure 3E and 3F .

[0086] The fixed shaping body 52 is shown in detail in Figure 5 , where it can be observed that it comprises a first portion 52a having a support function and a second portion 52b having a guide and folding function.

[0087] The first portion 52a has a substantially flat shape with a vertical extension, for example trapezoidal, to be anchored to an upper support structure (not shown). The second portion 52b has a cylindrical tubular shape with a cross section with a bottom opening and is configured to give the tubular shape to the second continuous web B during its progressive winding on the outer surface of the second portion 52b. The second portion 52b has an inner surface facing the guide rod 23 and an outer surface around which the continuous web B is progressively folded.

[0088] In another embodiment, not shown, the second portion 52b of the fixed forming body 52 can have a different shape (for example, elliptical, multilobed, irregular, etc.) depending on the shape of the guide rod 23 and therefore on the shape imparted to the first continuous web A in the forming station 20.

[0089] Operationally, at the outlet of the overlapping zone 40, the first continuous web A and the second continuous web B are glued at the flat first side 1 b of the first continuous web A and slide along the first conveying path so that the second continuous web B is placed on the belt 51 while the first continuous web A is supported by the guide rod 23.

[0090] In an initial portion of the packaging station 50 (in which the first continuous web A is unwound from the first reel 10 and the second continuous web B is unwound from the second reel 20), the belt 51 begins to wind the second continuous web B on the outer surface of the fixed forming body 52, in particular on the second portion 52b. Figure 3E At the same time, the first continuous web A, having the shaped configuration, is supported and guided by the guide rod 23 inside the second portion 52b of the forming body 52, so as to be positioned in the gap delimited by the guide rod 23 and the inner surface of the second portion 52b of the forming body 52.

[0091] In this case, the central portion 1 a of the first web A is conveyed inside said gap, thus preventing the deformation or elastic return of one or more end petals, represented in the drawings by the straight portion 1 b, when they are conveyed outside the gap and progressively folded around the outer surface of the forming body 52.

[0092] More specifically, as shown in the order indicated, Figures 3D-3F during the progressive winding of the second continuous web B, the belt 51 presses the first continuous web A and the second continuous web B against each other at least at the longitudinal glue line 33, i.e. at the contact surface between the end petals 1 b of the first continuous web A and the second continuous web B.

[0093] In this way, as shown, Figure 3F the fixed forming body 52 forms a support contact element for the separation contact surface between the two webs A, B, with the second continuous web B superimposed on the end petals 1 b.

[0094] Advantageously, the combination of the fixed forming body 52 and the belt 51 ensures that the webs A, B are glued even during the winding of the second continuous web B on the first continuous web A.

[0095] The machine M also comprises, upstream and / or near the packaging station 50, a second gluing device 60 configured to apply an adhesive (for example, glue) on the second continuous web B according to one or more lines designed to close the outer tubular element, preferably parallel to each other.

[0096] More specifically, as shown in Figure 3G the stepwise winding of the second continuous web B, the second glue application device 60 applies at least one line of glue along the side strip 2b of the second continuous web B, so as to close the tubular element T in the outlet portion of the packaging station 50, with the side strip 2b of the second continuous web B superimposed on the other side strip 2a.

[0097] In the preferred embodiment, the second glue application device 60 applies the line of glue along the protruding joint zone 2b, so that the lowered zone 2a can be placed thereon to form a smooth continuous tubular element T, without having interruptions due to the superimposition of the side strips 2a, 2b. More generally, the second glue application device 60 applies the line of glue along the first side strip 2a of the second continuous web B, which is to be superimposed with the second side strip 2b.

[0098] Advantageously, the second glue application device 60 allows the side strips 2a, 2b of the second continuous web B to be progressively glued during their winding, so as to place the line of glue in a more controlled manner.

[0099] Advantageously, the second glue application device 60 allows the side strips 2a, 2b of the second continuous web B to be progressively glued, so as to minimize the rough edges of the line of glue on the outer wall of the continuous tubular element T.

[0100] Downstream of the packaging station 50, in particular downstream of the second glue application device 60, the continuous tubular element T is conveyed by a lower support 45, which preferably defines a portion or an extension of the forming beam 50a, so as to slide under a compacting unit 70. The compacting unit 70 is configured to keep the second side strip 2a of the second continuous web B superimposed on the first side strip 2b, so as to keep the continuous tubular element T closed.

[0101] As shown in Figure 3H , the compacting unit 70, as a contact element of the first side strip 2a and of the second side strip 2b, prevents the risk of the side strips 2a, 2b separating from each other and thus opening the continuous tubular element T.

[0102] Preferably, in order to prevent this, the guide rod 23 extends at the compacting unit 70 during the sliding of the continuous tubular element T under the compacting unit 70. In this case, the guide rod 23 acts as a support contact of the compacting unit 70, so as to prevent the cross section of the continuous tubular element T from flattening.

[0103] As shown in Figure 3H , the machine M further comprises, downstream of the packaging station 50, preferably downstream of the second glue application device 60, an activation device 80 configured to perform a heat exchange on the continuous tubular element, so as to facilitate the temperature change of the line of glue released by the second glue application device 60.

[0104] More specifically, if the adhesive line is made of "hot melt" type adhesive, then the activation device 80 cools the adhesive line itself.

[0105] On the other hand, if the adhesive line is made of different adhesives, such as PVA adhesive, the activation device 80 heats the adhesive line itself.

[0106] The activation device 80 is integrated with the pressing unit 70 to activate the adhesive properties of the adhesive thread and simultaneously promote and maintain the mutual adhesion of the side strips 2a, 2b of the second continuous roll B.

[0107] In another feasible implementation, the activation device 80 is located away from the pressing unit 70, so that it can activate the adhesive properties of the adhesive line at a later stage.

[0108] Machine M also includes a cooling / heating station 90 downstream of packaging station 60, particularly at or downstream of pressing device 70 and / or activation device 80. Specifically, similar to the description of activation device 80 above, if the adhesive line is made of "hot melt" type adhesive, then station 90 is a cooling station and cools the adhesive line itself. Conversely, if the adhesive line is made of a different type of adhesive, such as PVA adhesive, then station 90 is a heating station and heats the adhesive line itself.

[0109] The cooling / heating station 90 includes a cooling / heating element 91 positioned facing the continuous tubular element T while the side strips 2a, 2b of the second continuous roll B overlap.

[0110] like Figure 3I As shown, the cooling / heating element 91 has an integrated cooling / heating system and a flat plate shape shaped to match the continuous tubular element T. The plate has a recessed portion with its cavity facing downwards to face the continuous tubular element T. More specifically, the recessed portion is shaped to match the continuous tubular element T to be cooled / heated, thereby facilitating the sliding of the continuous tubular element T and preventing the risk of it flattening in the portion in contact with the plate.

[0111] Advantageously, the presence of the cooling / heating station 90 allows for the fixed side belts 2a, 2b.

[0112] Advantageously, the cooling / heating element 91 allows the adhesive line to dry quickly, thereby avoiding problems associated with the possible opening of the continuous tubular element T.

[0113] In one embodiment, the cooling / heating element 91 is formed as a single piece; in other words, the cooling / heating element 91 comprises a single plate shaped to mate with the continuous tubular element T. In an alternative embodiment, the cooling / heating element 91 may comprise multiple plates shaped to mate with the continuous tubular element T and positioned one after another. Advantageously, using multiple plates allows for optimized cooling / heating.

[0114] In the preferred embodiment, downstream of the packaging station 50 and preferably downstream of the cooling / heating station 90, the machine M further comprises an extrusion device 100 configured to shape the cross section of the continuous tubular element T.

[0115] In fact, during the steps of forming the continuous tubular element T through the various workstations of the machine M, the continuous tubular element T undergoes slight deformations, for example flattening with consequent slight lateral bulging.

[0116] The extrusion device 100 comprises first and second extrusion rollers 101, 102, which face each other and have a profile shaped so as to define a gap for the passage of the continuous tubular element T.

[0117] More specifically, the extrusion rollers 101, 102 are preferably independently adjustable towards / away from each other, for example by means of an actuator 103, to vary the passage of the continuous tubular element T, so as to shape the cross section of the continuous tubular element T according to the desired shape, in particular circular.

[0118] Preferably, the extrusion rollers 101, 102 are idle.

[0119] According to another aspect of the application, downstream of the machine M there can be a device for cutting the continuous tubular element T into discrete tubular segments equipped with shaped inserts formed using a portion of the first continuous web A having a shaped configuration. In this case, the machine M is configured for manufacturing continuous segments.

[0120] The present application achieves the above-mentioned aims, eliminating the drawbacks that are highlighted in the prior art.

[0121] The presence of the guide rod 23 eliminates problems relating to accidental or unwanted deformations and / or folds of the first continuous web A with respect to the shaped configuration.

[0122] In particular, the guide rod 23 acts as a made and shaped guide of the first continuous web A during its transport between the workstations of the machine M, facilitating the precise shaping of the first continuous web A.

[0123] The guide rod 23 also acts as a contact for the components of the various workstations of the machine M, so that each component can perform the respective operating steps while the first continuous web A remains in the shaped configuration.

[0124] The guide rod 23 is also adapted to impart any shape to the first continuous web A, thus allowing the processing of inserts of any desired shape. More specifically, the shape of the first continuous web A can be any shape other than circular, and thus can be different from the shape (circular) assumed by the second continuous web B. Preferably, in cross section, the shape of the first continuous web A is such as to cross the second continuous web B wound (i.e. to span between two opposite contact points, the inner space being defined by the final tubular element formed by the winding of the second continuous web B).

[0125] The method for manufacturing the continuous tubular element T, performed using the machine M, is particularly efficient and reliable, especially during the step of winding the second continuous web B on the first continuous web A, since it ensures that the continuous tubular element T (external wrapping paper and internal insert) is formed with a regular shape.

Claims

1. A machine (M) for manufacturing a continuous tubular element (T) comprising a filler having spacing and / or filtering functions, comprising: - first conveying means (10) for conveying at least one first continuous web (A) and configured to convey said at least one first continuous web (A) along at least one first conveying path; - second conveying means (30) for conveying at least one second continuous web (B) and configured to convey said at least one second continuous web (B) along a respective second conveying path, said first and second conveying paths converging towards an overlapping zone (40); - a forming station (20) located on said first conveying path and configured to fold and / or deform said first continuous web (A) into a shaped configuration in which said first continuous web (A) assumes a non-circular shape in a cross section transversal to said first conveying path; - a packaging station (50) downstream of said overlapping zone (40) in which said second continuous web (B) is wrapped in a tubular shape on said shaped first continuous web (A) to obtain a continuous tubular element (T), wherein at least one of said forming station (20) and said packaging station (50) comprises at least one guide rod (23) which extends longitudinally along said first conveying path and / or around which said first continuous web (A) is at least partially formed and / or guided.

2. The machine (M) according to claim 1, wherein, said non-circular shape is a three-dimensional shape.

3. The machine (M) according to claim 1, wherein, said non-circular shape is an arcuate shape.

4. The machine (M) according to claim 1, wherein, said guide rod (23) extends for the entire longitudinal extension of said packaging station (50).

5. The machine (M) according to claim 1, wherein, said guide rod (23) extends for the entire longitudinal extension of said packaging station (50) until said second continuous web (B) in a tubular shape is completely wrapped on said first continuous web (A).

6. The machine (M) according to any one of claims 1 to 5, wherein, said guide rod (23) extends longitudinally along said first conveying path in said forming station (20) and in said packaging station (50).

7. The machine (M) according to any one of claims 1 to 5, wherein, said guide rod (23) is fixed to a frame of said machine (M) at or near said forming station (20).

8. The machine (M) according to any one of claims 1 to 5, wherein, said guide rod (23) has a constant cross section.

9. The machine (M) according to any one of claims 1 to 5, wherein, said guide rod (23) has a solid cross section.

10. The machine (M) according to any one of claims 1 to 5, wherein, at least one of said forming station (20) and said packaging station (50) comprises two or more guide rods (23) which are parallel and around which respective portions of said first continuous web (A) are at least partially formed and / or guided.

11. The machine (M) according to any one of claims 1 to 5, wherein, at least one of said forming station (20) and said packaging station (50) comprises two or more guide rods (23) which are side by side and around which respective portions of said first continuous web (A) are at least partially formed and / or guided.

12. The machine (M) according to any one of claims 1 to 5, wherein, said forming station (20) comprises a pair of pre-forming rollers (21, 22) between which said first continuous web (A) is conveyed, said pre-forming rollers (21, 22) being located upstream of said guide rod (23) and having respectively an outer profile shaped to match each other to perform a first permanent shaping of said first continuous web (A).

13. The machine (M) according to claim 12, wherein, The forming station (20) comprises, downstream of the pre-forming rollers (21, 22), a pair of forming elements (26, 27) which oppose each other and cooperate with the guide rod (23) to perform a second permanent forming of the first continuous web (A) while it is at least partially wound on the guide rod (23).

14. The machine (M) according to claim 13, wherein The forming elements (26, 27) comprise two fixed folders defined by respective plates fixed to the frame of the machine (M) and have respective folding edges (26a, 27a) which converge and are configured to move towards each other and permanently deform respective longitudinal portions of the first continuous web (A).

15. The machine (M) according to any one of claims 1 to 5, wherein, The packaging station (50) comprises a forming beam (50a) configured to progressively wind the second continuous web (B) on the first continuous web (A) having the shaped configuration, and wherein the at least one guide rod (23) extends along at least one segment of the packaging station (50) to support the corresponding configuration of the first continuous web (A) having the shaped configuration during winding of the second continuous web (B).

16. The machine (M) according to claim 15, wherein The forming beam (50a) is configured to progressively wind the second continuous web (B) on the first continuous web (A) having the shaped configuration using a guide and folding belt for the second continuous web (B).

17. The machine (M) according to claim 15, wherein The packaging station (50) further comprises a fixed forming body (52) interposed between the at least one guide rod (23) and the forming beam (50a) at least for one segment of the packaging station (50) for defining a folding reference surface of the second continuous web (B) around the first continuous web (A) having the shaped configuration.

18. The machine (M) according to claim 17, wherein The fixed forming body (52) is configured to be positioned around the at least one guide rod (23) with a predetermined overlap angle greater than 180°.

19. The machine (M) according to claim 17, wherein The fixed forming body (52) is configured to be positioned around the at least one guide rod (23) with a predetermined overlap angle greater than 270°.

20. The machine (M) according to any one of claims 1 to 5, comprising first gluing means (31) located upstream and / or near the packaging station (50) and configured to apply adhesive on the second continuous web (B) according to one or more lines.

21. The machine (M) according to any one of claims 1 to 5, wherein, comprising first gluing means (31) located upstream and / or near the packaging station (50) and configured to apply adhesive on the second continuous web (B) according to a plurality of lines parallel to each other.

22. The machine (M) according to any one of claims 1 to 5, comprising downstream of the packaging station (50) an extrusion device (100) having a first extrusion roller (101) and a second extrusion roller (102) facing each other and having respectively a shaped profile defining a gap for the passage of the continuous tubular element (T), and wherein the extrusion rollers (101, 102) are adjustable towards / away from each other to adjust the gap for the passage of the continuous tubular element (T) to shape the cross section of the continuous tubular element (T) according to a desired shape.

23. The machine (M) according to claim 22, wherein The desired shape is circular.

24. A method for manufacturing a continuous tubular element (T) comprising a filling having a spacing and / or filtering function, comprising the steps of: feeding at least one first continuous web (A) along a first conveying path; feeding at least one second continuous web (B) along at least one respective second conveying path; shaping the first continuous web (A) to impart to the first continuous web (A) a shaped configuration which is non-circular; winding the second continuous web (B) on the shaped first continuous web (A) to obtain a continuous tubular element (T) defined by a tubular casing housing the first continuous web (A) having the shaped configuration, wherein at least one of the shaping step and the winding step is performed using a guide rod (23) around which the first continuous web (A) is formed and / or guided.

25. The method of claim 24, wherein, The non-circular shape is a three-dimensional shape.

26. The method of claim 24, wherein, The non-circular shape is an arcuate shape.

27. The method of claim 24, wherein, The shaping step is performed continuously by stepwise folding and / or winding the first continuous web (A) around the guide rod (23) and wherein the first continuous web (A) is made to slide around the guide rod (23) and remain wound thereon until the step of winding the second continuous web (B) on the first continuous web (A) is completed.

28. The method of any one of claims 24 to 27, wherein, The shaping step comprises a first step of imparting a first permanent deformation to the first continuous web (A).

29. The method of claim 28, wherein, The first continuous web (A) is imparted a first permanent deformation using a pair of pre-shaping rollers (21, 22) located upstream of the guide rod (23) and having respectively an outer profile shaped to match each other.

30. The method of claim 29, wherein, The shaping step comprises a second step of imparting a second permanent deformation to the pre-shaped first continuous web (A) around the guide rod (23) using a pair of shaping elements (26, 27) opposite each other and comprising two fixed folding devices respectively having converging folding edges (26a, 27a) configured to move towards each other and permanently deform respective longitudinal portions of the first continuous web (A).

31. The method of any one of claims 24 to 27, wherein, The winding step is performed by progressively winding the second continuous web (B) on the first continuous web (A) while guiding at least a portion of the first continuous web (A) in a gap between the guide rod (23) and a fixed forming body (52), and wherein the second continuous web (B) is progressively wound on the first continuous web (A) by winding the second continuous web (B) on an outer surface of the fixed forming body (52).

32. The method of claim 31, wherein, The second continuous web (B) is progressively wound on the first continuous web (A) while one or more end petals (1b) of the first continuous web (A) are located outside the gap and are progressively folded around the outer surface of the fixed forming body (52) so that the second continuous web (B) is superposed on the one or more end petals (1b). The second continuous web (B) is progressively wound on the first continuous web (A) while one or more end petals (1b) of the first continuous web (A) are located outside the gap and are progressively folded around the outer surface of the fixed forming body (52) so that the second continuous web (B) is superposed on the one or more end petals (1b).

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