Machine and method for manufacturing continuous tubular elements with spacer and / or filter fillings

Abstract

A machine (M) for producing continuous tubular elements with fillings from web material is described. The machine (M) comprises first and second means (10, 30) for supplying respective continuous webs (A, B), a forming station (20) configured to fold and / or deform the first continuous web (A) into a shaped configuration, and a winding station (50), where the second continuous web (B) is tubularly wound around the shaped first continuous web (A) to obtain a continuous tubular element (T). Between the forming station (20) and the winding station (50) there is at least one guide bar (23) along which the first continuous web (A) is at least partially shaped and / or guided.

Description

[Technical Field]

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

[0002] More specifically, the continuous tubular element obtained in the context of the present invention can be used (after cutting) to form a series of segments suitable for use in aerosol generators or cigarettes having spacer, filter and / or cooling functions (e.g., filtering, spacer or cooling means). [Background technology]

[0003] Prior art homemade cigarettes consist of a paper tube wrapped around a paper filler, the paper filler being in the form of an insert or obtained using strips of said paper.

[0004] In the hand-made tube making method, an outer sheet of paper stock is rolled into the shape of a tube, and then a filler insert (usually made from a hand-folded piece of paper) is placed inside the outer tube to partially fill the cavity defined by the outer sheet.

[0005] These cigarettes, which are essentially made using pre-cut paper sheets, are very convenient to make by hand, but are not suitable for industrial production for obvious reasons of incompatibility with the manufacturing process, in particular because of the very low productivity that can be achieved by processing separate sheets: processing the inserts individually is indeed very time-consuming and, moreover, does not allow for reproducibility of quality results.

[0006] There are also prior art machines capable of producing continuous tubular elements comprising an outer tubular element and an inner filling obtained by shaping a web that is also continuous: in these machines, the inner web is subjected to a shaping operation to form the insert, and then the outer web is subjected to a wrapping operation to encase the insert so as to obtain a continuous tubular element.

[0007] Unfortunately, the above-mentioned machines have some problems with maintaining the shape of the inner web.

[0008] More specifically, during the process of wrapping the inner web with the outer web, the inner web may undergo deformation (eg, elastic return) and / or undesirable folding that alters the profile achieved during molding.

[0009] This results in a continuous tubular element with an insert that is not precise in cross section and whose shape does not correspond to the desired shape.

[0010] Furthermore, in order to encase the filler insert in the outer web, prior art machines require that the filler insert completely fill the tubular element, i.e., the cross-section of the filler insert after being gathered into a tubular shape must be substantially the same as the cross-section of the resulting continuous tubular element. Summary of the Invention

[0011] In this context, the technical object forming the basis of the present invention is to provide a machine and a method for manufacturing continuous tubular elements with a filling having spacer and / or filter function, which overcomes the above-mentioned drawbacks of the prior art.

[0012] More specifically, the object of the present invention is to provide a machine and method for producing continuous tubular elements having a filling with spacer and / or filter functions that allow effective shape control of the final product.

[0013] The stated technical and specified objects are substantially achieved by a machine and a method for manufacturing continuous tubular elements with a filling having spacer and / or filter function, comprising the technical features set out in claims 1 and 13 and / or in one or more of the claims dependent thereon. [Brief explanation of the drawings]

[0014] Further features and advantages of the present invention will become more apparent in the following detailed description, with reference to preferred but non-exclusive embodiments of a machine and method for manufacturing continuous tubular elements with a packing having spacer and / or filter function, as illustrated in the accompanying drawings. [Figure 1] 1 shows a schematic view of an embodiment of a machine for producing continuous tubular elements from a web material according to the invention; [Figure 2] FIG. 2 is a schematic diagram of an alternative embodiment of the machine of FIG. 1; [Figures 3A-3L] 3 is a series of cross-sectional views of the machine of FIG. 1 and / or FIG. 2, showing cross-sectional views with reference to corresponding section lines identified in FIG. 1 and FIG. 2. [Figure 4] 3 shows a cross section of a continuous tubular element obtained using the machine of FIG. 2. [Figure 4A] An enlarged detail of FIG. 4 is shown. [Figure 5] FIG. 3 is a perspective view of components of a station of the machine of FIG. 1 or FIG. 2; [Figure 6] 3E shows a variant embodiment of the detail of FIG. [Figure 7] 3B shows a variant embodiment of the detail of FIG. 3A. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 and 2, reference "M" denotes a machine for manufacturing a continuous tubular element "T" according to the invention, obtained from two continuous webs, preferably made of paper. More specifically, the continuous tubular element "T" has an insert or filling made of a first, appropriately shaped continuous web "A" and an outer cover formed by winding a second continuous web "B" around the first, pre-shaped continuous web "A".

[0016] In a preferred embodiment, the first continuous web "A" and the second continuous web "B" are made of a paper stock, however, the materials used may vary without altering the inventive concept of the present invention, even if made with a low thickness to provide sufficient flexibility and bendability.

[0017] More specifically, for one or both of the continuous webs, different materials may be used selected from the following materials (individually or mixed together): Cellulose-derived materials, such as cellulose acetate (tow), Tobacco, reconstituted tobacco or other plant-derived materials, such as wheat, corn, sugarcane, hemp, sugar beet, palm, pawpaw, Polymer plastic materials, such as polylactic acid (PLA), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), Biodegradable or compostable materials, such as Mater-Bi, a bioplastic that is a PHA (polyhydroxyalkanoate); Metals such as aluminum and stainless steel.

[0018] These materials may also include: Plasticizers, solvents or humectants, such as triacetin (glycerin triacetate), TEC (triethyl citrate), PEG 400 (low molecular weight polyethylene glycol), Vapor, smoke, or aerosol-producing materials, such as water, glycerol, propylene glycol, etc. natural or artificial flavors, such as menthol, fruit extracts, sugar, licorice, liqueur flavors, cocoa, Materials with selective or adsorptive filtering effects, such as activated carbon, silica gel, etc. A material that facilitates bonding of the web components by adhesive, typically PVA, vegetable or animal based adhesives, starch, alginates, fats, and the like.

[0019] The materials may be present simultaneously in the tube or web of the insert, or may be chemically mixed or mechanically bonded together by, for example, rolling, pressing, molding, compressing, extruding, coating, impregnation, sintering, adhesive bonding, powder or granule or wire inclusion, etc.

[0020] The web can be made using methods similar to those used to prepare paper or recon tobacco, plastic tape (eg, presses), or can be a mesh, textile, or nonwoven web.

[0021] The machine "M" comprises a first supply means 10 for supplying a first continuous web "A", configured to supply the first continuous web "A" along a first supply path, and a second supply means 30 for supplying a second continuous web "B", configured to supply the second continuous web "B" along a second supply path. Preferably, the first supply means 10 and the second supply means 30 comprise respective reels from which the continuous webs "A", "B" are gradually unwound, and suitable guide rollers arranged along the supply paths.

[0022] The machines of Figures 1 and 2 are identical in most of their features, differing only in that in the machine of Figure 1, the second continuous web "B" (defining the outer tubular element) maintains its thickness unchanged from the corresponding reel to the end of the processing step and in particular assumes a single-layer structure, while in the machine of Figure 2, the second continuous web "B" is folded twice along each longitudinal line to assume a three-layer structure (prior to tubular shaping).

[0023] For this purpose, the machine "M" comprises a folding unit 32 configured to fold the longitudinal bands of the second continuous web "B" around the respective longitudinal folds, in particular to obtain a three-layer web, the lateral edges 2a, 2b of which have respectively lowered zones 2a and raised joining zones 2b (shown in Figure 4A) designed to favour the closure of the continuous tubular element "T", as will be explained in more detail below.

[0024] As noted above, the remainder of the machine "M" remains the same for both the embodiments of FIGS.

[0025] The machine "M" also comprises a forming station (20) disposed in the first feed path and configured to fold and / or deform the first continuous web "A" into a shaped configuration, so that the first continuous web "A" is given a predetermined shape, in particular a three-dimensional shape and / or a curved shape, in a cross section transverse to the first feed path. In the context of the present invention, a particular shape is not limiting, since any shape other than circular may also be used. However, the accompanying drawings show non-limiting exemplary embodiments.

[0026] More particularly, the forming station 20 comprises a pair of preforming rollers 21, 22 having contours shaped to fit together (and thus preferably geometrically engaged to form a slit having a constant thickness) and defining a gap therebetween through which the first continuous web "A" is fed to undergo a first permanent shaping during rotation of the preforming rollers 21, 22.

[0027] In the embodiment shown in FIG. 3A, the preforming rollers 21, 22 have respective mating contours that, in a cross section taken in a plane through their axes, include a substantially semicircular section disposed between two straight sections.

[0028] In this embodiment, preforming rollers 21, 22 impart a first permanent shape to a first continuous web "A" having, in cross section, a substantially upwardly "U" shaped central portion 1a and two flat side portions 1b.

[0029] In a further possible embodiment, the contour of the preforming rollers 21, 22 may be formed by splines so as to form a shape with a series of curved sections, in particular different wavy sections.

[0030] In a further possible embodiment, the contour of the preforming rollers 21, 22 may be defined by straight sections alternating with curved portions or splines so as to impart any shape to the first continuous web "A".

[0031] In another embodiment according to FIG. 7, the preforming rollers 21, 22 have an outer shape that is shaped to form slits of non-constant thickness, i.e., that have a convex-concave connection but no geometric correspondence.

[0032] Downstream of the preforming rollers 21, 22, the machine "M" comprises a guide bar 23 around which the first continuous web "A" is at least partially formed and / or guided. The guide bar 23 thus forms a core around which the first, preformed continuous web "A" is fed.

[0033] Advantageously, thanks to the presence of the guide bar 23, undesired deformation and / or bending of the first continuous web "A" is avoided, for example, preventing the first continuous web "A" from deforming relative to the formed configuration obtained during the first forming step.

[0034] A guide bar 23 is fixed at the rear to the frame of the machine "M" adjacent or at the forming station 20 and extends longitudinally along the first feed path.

[0035] Preferably, the guide bar 23 is made as a rod having a constant complete cross section.

[0036] Even more preferably, the outer surface of the guide bar 23 is smooth to prevent wobbling of the first continuous web "A" during sliding / forming of the first continuous web "A" around the guide bar 23.

[0037] In the embodiment shown in the accompanying drawings, the machine M comprises a single guide bar 23 having a substantially circular cross section so as to support the central portion 1a of the first continuous web "A" in a forming configuration according to the first forming.

[0038] According to further embodiments in which the pre-forming rollers 21, 22 apply a first shaping to the first continuous web "A" different from those shown in the accompanying drawings, the machine "M" may comprise two or more guide bars 23 arranged parallel and / or side by side or otherwise around which respective portions of the first continuous web "A" are at least partially shaped and / or guided. In that case, the two or more guide bars 23 may also have a cross-section different in shape from circular, in particular a shape compatible with the matching shape imparted by the pre-forming rollers 21, 22.

[0039] An example of different arrangements of the guide bars 23 and different fitting shapes provided by the preforming rollers 21, 22 is shown in Figure 6, where two guide bars 23 are arranged parallel to each other to receive a first continuous web "A" that is substantially M-shaped.

[0040] Operatively, at the outfeed from the preforming rollers 21, 22, the first continuous web "A" is aligned with the guide bar 23 such that the preformed (central) portion 1a of the first continuous web "A" rests on the guide bar 23 and at least partially wraps around it.

[0041] In order to prevent elastic return of the first continuous web "A" downstream of the pair of preforming rollers 21, 22, the guide bar 23 may work in conjunction with a pair of guide elements 24, 25 formed, for example, in the form of metal bars or blocks extending parallel to the first feed path.

[0042] As shown in FIG. 3B, the pair of guide elements 24, 25 define a gap for the passage of the first continuous web "A" such that a longitudinal portion of the first continuous web "A" slides substantially in contact with the guide elements 24, 25.

[0043] The pair of guide elements 24, 25 thus define a passage having a fixed width so as to maintain the first continuous web "A" in the configuration assumed after the first shaping, and prevent associated longitudinal portions from moving away from each other, for example due to the elastic return of the material of the first continuous web "A".

[0044] Downstream of the pre-forming rollers 21, 22 and downstream of the guide elements 24, 25 (if present), the forming station 20 also comprises a pair of forming elements 26, 27 which oppose each other and act in conjunction with the guide bar 23 to produce a second permanent forming of the first continuous web "A".

[0045] Preferably, the pair of forming elements 26, 27 comprises two fixed folding units defined by respective plates that rotate relative to the frame of the machine "M", the two fixed folding units having respective folding edges 26a, 27a that are configured to converge and move towards each other to permanently deform respective longitudinal portions of the first continuous web "A".

[0046] 3C, forming elements 26, 27 push longitudinal portions of first continuous web "A" toward one another so that the cross-section of first continuous web "A" assumes a substantially "omega" shape ("Ω"). More specifically, as first continuous web "A" passes between forming elements 26, 27, flat side portions 1b move toward one another and central portion 1a curves to wrap further around guide bar 23.

[0047] The forming station 20 allows for the continuous forming of the first web "A" so that as the first web "A" leaves the station, the first continuous web "A" is formed and ready to be introduced as an insert into the continuous tubular element "T".

[0048] The forming process that causes the first continuous web "A" to assume a formed configuration is accomplished by gradually folding and / or wrapping the first continuous web "A" around a guide bar 23, where there is a first step in which a first permanent shape is imparted by pre-forming rollers 21, 22 and a second step in which a second permanent shape is performed by forming elements 26, 27, respectively.

[0049] According to an alternative embodiment not shown, the forming station 20 may be configured to perform only one of the above-mentioned preforming and forming steps and may therefore have only one of the corresponding respective forming means (more specifically, only one of the pair of preforming rollers 21, 22 and the pair of forming elements 26, 27).

[0050] According to an embodiment not shown, the machine "M" may comprise a sensor, e.g. an optical sensor, arranged downstream of the pre-forming rollers 21, 22 in order to detect defects in the first continuous web "A" and / or to control the centering of the first continuous web "A" downstream of the pre-forming rollers 21, 22. Essentially, the sensor is arranged at one end of the guide bar 23 in order to detect the first continuous web "A". The machine M may also comprise a control unit which receives data measured by the sensor and controls the first supply means 10 based on this data (by feedback).

[0051] As shown in Figures 1 and 2, downstream of forming station 20, machine M includes overlap zone 40, where first and second feed paths meet one another such that portions of first continuous web "A" overlap corresponding respective portions of second continuous web "B."

[0052] Advantageously, this overlapping occurs in a pre-bonded zone of the first continuous web "A" and / or the second continuous web "B." More specifically, bonding preferably occurs on the second continuous web "B" upstream of the overlapping zone.

[0053] To bond the continuous webs "A" and "B", the machine "M" comprises a first bonding device 31 arranged along the first and / or second feed path upstream of the overlapping zone 40 and configured to apply at least one longitudinal adhesive line 33 onto the first continuous web "A" and / or the second continuous web "B", respectively.

[0054] In the embodiment shown in the accompanying drawings, a first gluing device 31 is positioned along the second feed path to apply a line of adhesive 33 along the second continuous web "B."

[0055] The location of each of the longitudinal adhesive lines 33 defines a respective adhesive zone onto which a portion of the first continuous web "A" is applied so that the continuous tubular element "T" has a distinct line of contact and / or surface extending longitudinally (along the tubular element "T") between the continuous webs "A", "B". In other words, the number and / or arrangement of these longitudinal adhesive lines 33 are selected so that they correspond to respective distinct overlap zones between the two continuous webs "A", "B". The term "distinct" means longitudinal lines or surfaces that are laterally separated and / or spaced apart from one another.

[0056] Preferably, the first gluing device 31 is adjustable at least in relative lateral position, in particular perpendicular to the second supply path, to allow adaptation of the longitudinal glue line 33 in the case of format changeover.

[0057] In the embodiment shown in the accompanying drawings, the bonding device 31 includes two supply nozzles for applying two longitudinal (and parallel) adhesive lines 33 to the second continuous web "B" so as to define two adhesive zones designed to receive the flat side portions 1b of the first continuous web "A" formed into an "Omega" shape. In this situation, the second continuous web "B" is in a flat configuration and is positioned below the first continuous web "A" and then contacts at least a portion of the flat side portions 1b to define separate contact surfaces between the webs "A" and "B" present inside the continuous tubular web "T." It will be understood that the number of nozzles of the bonding device 31 can vary depending on the longitudinal lines to be formed.

[0058] In a further possible embodiment not shown, a first gluing device 31 is positioned upstream of the overlapping zone 40, preferably along the first feed path, and more preferably downstream of the forming station 20, and applies longitudinal adhesive lines 33 to the first continuous web "A." More specifically, in this embodiment, the longitudinal adhesive lines 33 are applied from below to parts of the lateral portions 1b of the first continuous web "A," defining two adhesive zones designed to receive corresponding respective portions of the second continuous web "B."

[0059] To prevent the first continuous web "A" from bending and / or deforming in a manner that would change its formed configuration during the bonding step, the guide bar 23 also extends through the overlap zone 40 so as to be interposed between the first continuous web "A" and the second continuous web "B."

[0060] In the illustrated embodiment, there is a first pair of rollers 41, 42 disposed in the overlapping zone 40. More specifically, the lower roller 42 of the pair of rollers 41, 42 drives a guide belt 51 of a forming beam 50a of a winding station 50, which will be described in more detail below. The roller 42 has a substantially smooth side. The second continuous web "B" is fed along a second feed path until the roller 42 is partially rotated (in contact with the guide belt 51) to pass from the overlapping zone 40 to the winding station 50.

[0061] The upper roller 41 of the pair of rollers 41, 42 is shaped to allow the guide bar 23 and the shaped continuous web "A" to pass over the upper roller 41. The upper roller 41 is preferably made of rubber. More specifically, the outer surface of the roller 41 is rubberized.

[0062] A first pair of rollers 41, 42 act in conjunction with guide bar 23 to maintain first continuous web "A" in a formed configuration and prevent first web "A" from flattening during bonding to second continuous web "B."

[0063] The machine M may also include a second pair of rollers 43, 44 located upstream of the overlapping zone 40 along the first conveying path. This second pair of rollers 43, 44 acts on the first, pre-formed continuous web "A" to keep a longitudinal portion of the first continuous web "A" at least partially wrapped around the guide bar 23, which prevents flattening of the central portion 1 a of the first continuous web "A" and thus facilitates maintaining the formed configuration. Furthermore, the second pair of rollers 43, 44 contributes to unwrapping and tensioning the first continuous web "A" in the forming zone 20.

[0064] Downstream of the overlapping zone 40, the machine "M" comprises a winding station 50, in which the second continuous web "B" is wound around the first, preformed continuous web "A" until it assumes a closed tubular shape, in particular with a circular cross section. More specifically, the overlapping zone 40 is infeed of the winding station 50, so that the second continuous web "B" can be placed between the roller 42 and the above-mentioned guide belt 51.

[0065] As shown in Figures 3E and 3F, the winding station 50 comprises a forming beam 50a configured to gradually wrap the second continuous web "B" around the first continuous web "A" in a formed configuration, preferably by using a guide and folding belt 51 for the second continuous web "B."

[0066] Advantageously, the guide bar 23 extends to the winding station 50, and in particular until the second continuous web "B" is completely wrapped around the first, preformed continuous web "A."

[0067] The winding station 50 also includes, at least in a section of the winding station 50, a stationary former 52 disposed between the guide bar 23 and the forming beam 50a, the stationary former 52 forming an interface for folding the second continuous web "B" around the first, preformed continuous web "A." More specifically, the stationary former 52 is configured to be disposed around the guide bar 23 by a predetermined overlap angle, preferably greater than 180°, and more preferably greater than 270°, as shown in Figures 3E and 3F.

[0068] It should be noted that the fixed mold 52 is shown in detail in FIG. 5 and comprises a first portion 52a having a support function and a second portion 52b having a guide and folding function.

[0069] The first portion 52a has a substantially vertically extending plate-like shape, e.g., trapezoidal, for fastening to an upper support structure (not shown). The second portion 52b has a cylindrical tubular shape with an open-bottom cross section and is configured to impart a tubular shape to the second continuous web "B" as it gradually folds around the outer surface of the second portion 52b. The second portion 52b has an inner surface facing the guide bar 23 and an outer surface around which the continuous web "B" gradually folds.

[0070] In another embodiment not shown, the second portion 52b of the fixed forming body 52 can have various shapes (e.g., oval, multi-lobed, irregular, etc.) depending on the shape of the guide bar 23 and therefore depending on the shape imparted to the first continuous web "A" at the forming station 20.

[0071] Operatively, at the outfeed from the overlapping zone 40, the first continuous web "A" and the second continuous web "B" are adhered at the flat side portion 1b of the first continuous web "A" and slide along the first feed path such that the second continuous web "B" is placed on the belt 51 while the first continuous web "A" is supported by the guide bar 23.

[0072] In the first section of the winding station 50 (FIG. 3E), the belt 51 begins to wrap the second continuous web "B" around the outer surface of the stationary former 52, particularly around the second portion 52b. At the same time, the first continuous web "A" in the formed configuration is supported and guided by the guide bar 23 within the second portion 52b of the former 52 so as to be positioned within the gap defined by the guide bar 23 and the inner surface of the former 52, particularly the second portion 52b of the former 52.

[0073] In this situation, the central portion 1a of the first web "A" is fed into the gap so as to prevent deformation or elastic return, and one or more end flaps, represented in the accompanying drawings by straight portions 1b, are fed outside the gap and gradually folded around the outer surface of the forming body 52.

[0074] More specifically, as shown in the sequence of Figures 3D-3F, during the progressive winding of the second continuous web "B," the belt 51 compresses the first continuous web "A" and the second continuous web "B" relative to one another at least at the longitudinal adhesive line 33, i.e., at the interface between the end flap 1b of the first continuous web "A" and the second continuous web "B."

[0075] In this way, as shown in FIG. 3F, the fixed mold 52 forms a supporting contact element for compressing the individual contact surfaces between the two webs "A", "B" where the second continuous web "B" is superimposed on the end flap 1b.

[0076] Advantageously, the combined action of stationary former 52 and belt 51 ensures that webs "A" and "B" remain adhered together even while second continuous web "B" is being wrapped around first web "A."

[0077] The machine "M" also comprises a second gluing device 60 upstream of and / or adjacent to the winding station 50, the second gluing device 60 being configured to apply adhesive, e.g., glue, onto the second continuous web "B" according to one or more lines, preferably parallel to one another, designed to close the outer tubular element.

[0078] More specifically, as shown in FIG. 3G, during the progressive winding of the second continuous web "B," the second bonding device 60 applies at least one line of adhesive along a side band 2b of the second continuous web "B" in the outfeed section of the winding station 50 so that the side band 2b of the second continuous web "B" overlaps a further side band 2a to close the tubular element "T."

[0079] In a preferred embodiment, the second bonding apparatus 60 applies a line of adhesive along the raised bonding zone 2b so that the lowered zone 2a can be positioned over the raised bonding zone 2b to form a smooth continuous tubular element "T" without the interruption created by the overlapping of the side bands 2a, 2b. More generally, the second bonding apparatus 60 applies a line of adhesive along the first side band 2a of the second continuous web "B" onto which the second side band 2b will be overlapped.

[0080] Advantageously, the second bonding device 60 allows for the gradual bonding of the side bands 2a, 2b of the second continuous web "B" during winding of the side bands 2a, 2b of the second continuous web "B" so as to apply the adhesive lines in a more controlled manner.

[0081] Advantageously, the second bonding device 60 allows for gradual bonding of the side bands 2a, 2b of the second continuous web "B" minimizing rough edges of the adhesive line on the outer wall of the continuous tubular element "T".

[0082] Downstream of the winding station 50, in particular downstream of the second gluing device 60, the continuous tubular element "T" is fed, preferably by means of a lower support 45 defining a development of a forming beam 50a or part thereof, to slide under a press unit 70. The press unit 70 is configured to maintain the second lateral band 2a superimposed on the first lateral band 2b of the second continuous web "B" so as to maintain the closure of the continuous tubular element "T".

[0083] As shown in Figure 3H, the pressing unit 70 acts as a contact element for the first and second lateral bands 2a, 2b, preventing the lateral bands 2a, 2b from separating from each other and risking opening of the continuous tubular element "T".

[0084] Preferably, the guide bar 23 extends to the press unit 70 to prevent the continuous tubular element "T" from being flattened so as to change its cross-sectional shape while it slides under the press unit 70. In that case, the guide bar 23 functions as a support contact for the press unit 70 to prevent flattening of the cross section of the continuous tubular element "T".

[0085] As shown in FIG. 3H, the machine "M" also includes, downstream of the winding station 50 and preferably downstream of the second bonding device 60, an activation device 80 configured to perform heat exchange with the continuous tubular element to promote a change in the temperature of the adhesive line discharged by the second bonding device 60.

[0086] More particularly, if the glue line is made from a "hot melt" type adhesive, the activation device 80 cools the glue line itself.

[0087] On the other hand, if the glue line is made from a different glue, for example PVA glue, the activation device 80 heats the glue line itself.

[0088] An activation device 80 is integrated with the press unit 70 to activate the adhesive properties of the adhesive lines while promoting and maintaining the mutual adhesion of the side bands 2a, 2b of the second continuous web "B."

[0089] In another possible embodiment, the activation device 80 is separate from the press unit 70 so that the adhesive properties of the adhesive line can be activated at a later stage.

[0090] Machine "M" also comprises a cooling / heating station 90 downstream of winding station 50, and particularly downstream of or at the press unit 70 and / or activation device 80. In particular, similar to what has been described above with respect to activation device 80, if the glue line is made from a "hot melt" type adhesive, station 90 is a cooling station, cooling the glue line itself. In contrast, if the glue line is made from a different adhesive, for example a PVA adhesive, station 90 is a heating station, heating the glue line.

[0091] The cooling / heating station 90 comprises a cooling / heating element 91 positioned facing the continuous tubular element "T" on which the side bands 2a, 2b of the second continuous web "B" are superimposed.

[0092] As shown in Figure 3I, the cooling / heating element 91 has an integrated cooling / heating system and has the form of a plate shaped to fit over the continuous tubular element "T". The plate has a concave portion with a concave surface facing downward to face the continuous tubular element "T". More specifically, the concave portion is shaped to fit over the continuous tubular element "T" to be cooled / heated in a way that facilitates sliding of the continuous tubular element "T" and prevents the risk of flattening where it contacts the plate.

[0093] Advantageously, the presence of the cooling / heating station 90 allows for the fixing of the lateral bands 2a, 2b.

[0094] Advantageously, the cooling / heating element 91 allows the adhesive line to dry quickly so as to avoid problems associated with possible opening of the continuous tubular element "T".

[0095] In one embodiment, the cooling / heating element 91 is made in one piece. In other words, the cooling / heating element 91 consists of a single plate shaped to fit the continuous tubular element "T". In an alternative embodiment, the cooling / heating element 91 may comprise multiple plates shaped to fit the continuous tubular element "T" and arranged one after the other. Advantageously, the use of multiple plates allows for optimization of the cooling / heating.

[0096] In a preferred embodiment, downstream of the winding station 50, and preferably downstream of the cooling / heating station 90, the machine "M" also comprises a compression device 100 configured to model the cross section of the continuous tubular element "T".

[0097] In practice, during the steps of producing the continuous tubular element "T" through the various stations of the machine "M", the continuous tubular element "T" may become slightly deformed, for example flattened and slightly convex laterally.

[0098] The compaction device 100 comprises first and second compaction rollers 101, 102 facing each other and having respective contours shaped to define a gap for the passage of the continuous tubular element "T".

[0099] More specifically, the compression rollers 101, 102 are preferably independently adjustable towards / away from each other, for example by actuator 103, to vary the path for the continuous tubular element "T" so as to form a desired shape, in particular a circular cross section of the continuous tubular element "T".

[0100] Preferably, the compression rollers 101, 102 are idle.

[0101] According to another aspect of the invention, machine "M" may be followed by a device for cutting the continuous tubular element "T" into individual tubular segments with molded inserts formed using portions of the first continuous web "A" in a molded configuration. In this situation, machine "M" is configured as a machine for producing individual segments.

[0102] The present invention achieves the above-mentioned objectives and eliminates the drawbacks highlighted in the prior art.

[0103] The presence of guide bar 23 eliminates problems associated with accidental and undesirable deformation and / or folding of first continuous web "A" relative to the formed configuration.

[0104] In particular, the guide bar 23 acts as a support and forming guide for the first continuous web "A" during feeding of the first continuous web "A" between stations of the machine "M" to facilitate accurate forming of the first continuous web "A".

[0105] The guide bar 23 also serves as a contact point for the components of the various stations of the machine "M", allowing each component to perform its respective operating step while maintaining the first continuous web "A" in its formed configuration.

[0106] The guide bar 23 is also adaptable to any type of shape imparted to the first continuous web "A" and can therefore process any type of desired shaped insert. More specifically, the shape of the first continuous web "A" may be arbitrary and not circular, and therefore may differ from the shape (circular) assumed by the second continuous web "B." Preferably, in cross section, the first continuous web "A" has a shape such that it passes laterally through the second wound continuous web "B" (i.e., between two or more opposing contact points, it transversely traverses the interior space defined by the final tubular element formed by the winding of the second continuous web "B").

[0107] The method for manufacturing the continuous tubular element "T" carried out using the machine "M" is efficient and reliable, especially during the step of winding the second continuous web "B" around the first continuous web "A", because it is guaranteed that the continuous tubular element "T" (outer wrapper and inner insert) will be formed in a regular shape.

Claims

1. A machine (M) for producing continuous tubular elements (T) with spacer and / or filter packings, comprising: a first supply means (10) for supplying at least a first continuous web (A), the first supply means (10) being configured to supply said at least first continuous web (A) along at least a first supply path; a second supply means (30) for supplying at least a second continuous web (B), the second supply means (30) being configured to supply said at least second continuous web (B) along a second supply path, said first supply path and said second supply path merging towards a laying zone (40); a forming station (20) disposed on the first feed path and configured to perform folding and / or deformation of the first continuous web (A) into a formed configuration, wherein the first continuous web (A) has a non-circular shape, and the non-circular shape does not overlap a circumference; a winding station (50) downstream of the overlapping zone (40), in which the second continuous web (B) is wound in a tubular shape around the formed first continuous web (A) to obtain a continuous tubular element (T); At least one of the forming station (20) and the winding station (50) comprises at least one guide bar (23) extending longitudinally along the first feed path and / or along which the first continuous web (A) is at least partially formed and / or guided.

2. A machine (M) as described in claim 1, wherein the first continuous web (A) has a three-dimensional shape and / or a curved shape in cross section transverse to the first supply path.

3. 3. A machine (M) according to claim 1 or 2, wherein the guide bar (23) extends over the entire longitudinal extension of the winding station (50).

4. A machine (M) as described in claim 3, wherein the guide bar (23) extends until the second continuous web (B) is completely wound around the first continuous web (A) in a tubular shape.

5. 5. A machine (M) according to any one of claims 1 to 4, wherein the guide bar (23) extends longitudinally along the first feed path in the forming station (20) and in the winding station (50).

6. 6. A machine (M) according to any one of claims 1 to 5, wherein the guide bar (23) is fixed to a frame of the machine (M) at or adjacent to the forming station (20).

7. 7. Machine (M) according to any one of claims 1 to 6, wherein said guide bar (23) has a constant cross section.

8. A machine (M) as described in claim 7, wherein the guide bar (23) has a solid cross section.

9. 9. The machine (M) according to any one of claims 1 to 8, wherein at least one of the forming station (20) and the winding station (50) comprises two or more guide bars (23) arranged parallel and / or side by side, around which corresponding respective portions of the first continuous web (A) are at least partially formed and / or guided.

10. 10. The machine (M) according to any one of claims 1 to 9, wherein the forming station (20) comprises a pair of pre-forming rollers (21, 22) between which the first continuous web (A) is fed, the pair of pre-forming rollers (21, 22) being arranged upstream of the guide bar (23) and having respective contours shaped to mate with each other to impart a first permanent shape to the first continuous web (A).

11. 11. The machine (M) according to claim 10, wherein the forming station (20) also comprises a pair of forming elements (26, 27) downstream of the pair of pre-forming rollers (21, 22) facing each other and cooperating with the guide bar (23) to perform a second permanent forming of the first continuous web (A) while the first continuous web (A) is at least partially wrapped around the guide bar (23).

12. A machine (M) as described in claim 11, wherein the pair of forming elements (26, 27) comprise two fixed folders having respective folding edges (26a, 27a) configured to converge and move towards each other to permanently deform respective longitudinal portions of the first continuous web (A).

13. A machine (M) as described in claim 12 when dependent on claim 6, wherein the two fixed folders are defined by respective plates fixed to the frame of the machine (M).

14. 14. The machine (M) according to any one of claims 1 to 13, wherein the winding station (50) comprises a forming beam (50a) configured to progressively wrap the second continuous web (B) around the first continuous web (A) in the shaped configuration, and wherein the at least one guide bar (23) extends along at least one section of the winding station (50) to support the corresponding configuration of the first continuous web (A) in the shaped configuration during the winding of the second continuous web (B).

15. A machine (M) as described in claim 14, wherein the forming beam (50a) is configured to progressively wrap the second continuous web (B) around the first continuous web (A) in the formed configuration using guide and folding belts for the second continuous web (B).

16. A machine (M) as described in claim 14 or 15, wherein the at least one guide bar (23) extends over the entire deployment of the winding station (50).

17. 17. The machine (M) according to any one of claims 14 to 16, wherein the winding station (50) also comprises a fixed former (52) arranged between the at least one guide bar (23) and the forming beam (50a), at least in a section of the winding station (50), to define a reference plane for folding the second continuous web (B) around the first continuous web (A) in the formed configuration.

18. A machine (M) as described in claim 17, wherein the fixed molding (52) is configured to be arranged around the at least one guide bar (23) over a predetermined overlap angle.

19. A machine (M) as described in claim 18, wherein the predetermined overlap angle is an angle greater than 180° or an angle greater than 270°.

20. 20. The machine (M) according to any one of claims 1 to 19, comprising a first gluing device (31) arranged upstream of and / or in the vicinity of the winding station (50) and configured to apply an adhesive substance to the second continuous web (B) according to one or more lines.

21. A machine (M) as described in claim 20, wherein the multiple lines are parallel to each other.

22. 22. The machine (M) according to any one of claims 1 to 21, comprising a compression device (100) downstream of the winding station (50), the compression device (100) having first and second compression rollers (101, 102) facing each other and having respective contours for defining a gap for the passage of the continuous tubular element (T), the first and second compression rollers (101, 102) being adjustable to move closer to or farther away from each other to adjust the gap for the passage of the continuous tubular element (T) so as to shape the cross-section of the continuous tubular element (T) according to a desired shape.

23. A machine (M) as described in claim 22, wherein the desired shape is circular.

24. 1. A method for manufacturing a continuous tubular element (T) with a packing having spacer and / or filter function, comprising: feeding at least a first continuous web (A) along a first feeding path; feeding at least a second continuous web (B) along at least a second feeding path; a forming step of forming the first continuous web (A) to give the first continuous web (A) a non-circular formed configuration, the non-circular formed configuration not overlapping a circumference; a winding step of winding the second continuous web (B) around the first shaped web (A) to obtain a continuous tubular element (T) defined by a tubular cover that houses the first continuous web (A) in a shaped configuration, The method, wherein at least one of the forming step and the winding step is carried out using a guide bar (23) around which the first continuous web (A) is formed and / or guided.

25. The method described in claim 24, wherein the non-circular shaped configuration is a three-dimensional configuration and / or a curved configuration.

26. 26. The method according to claim 24 or 25, wherein the forming step is carried out continuously by gradually folding and / or wrapping the first continuous web (A) around the guide bar (23), and the first continuous web (A) is slid and kept wrapped around the guide bar (23) until the step of wrapping the second continuous web (B) around the first continuous web (A) is completed.

27. 27. The method according to any one of claims 24 to 26, wherein the shaping step comprises a first step of imparting a first permanent deformation to the first continuous web (A).

28. A method as described in Claim 27, wherein the first step is carried out using a pair of pre-forming rollers (21, 22) positioned upstream of the guide bar (23) and having respective outer shapes shaped to fit together.

29. A method according to claim 27 or 28, comprising a second step of performing a second permanent deformation of the first continuous web (A) previously pre-formed around the guide bar (23).

30. A method as described in Claim 29, wherein the second step is carried out using a pair of forming elements (26, 27) facing each other and comprising two fixed folding devices, the two fixed folding devices having respective folding edges (26a, 27a) configured to converge and move towards each other to permanently deform respective longitudinal portions of the first continuous web (A).

31. 31. The method according to any one of claims 24 to 30, wherein the winding step is performed by gradually winding the second continuous web (B) around the first continuous web (A) while at least a portion of the first continuous web (A) is guided in a gap between the guide bar (23) and a fixed former (52), and the gradually winding of the second continuous web (B) around the first continuous web (A) is performed by winding the second continuous web (B) around the outer surface of the fixed former (52).

32. 32. The method of claim 31, wherein the progressive wrapping of the second continuous web (B) around the first continuous web (A) is performed while one or more end flaps (1b) of the first continuous web (A) are positioned outside the gap and the second continuous web (B) is progressively folded around the outer surface of the fixed forming body (52) so as to overlap the one or more end flaps (1b).

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