Machine and method for the manufacture of tubular articles and tubular articles

Abstract

A machine (M) for the production of tubular articles (A), particularly for the food or tobacco industries, comprising first feeding means (100) for at least one first web (N1) and second feeding means (200) for at least one second continuous web (N2). The machine (M) includes an embossing station (300) designed to impart a permanent surface deformation on at least one side of the first continuous web (N1) in accordance with a predetermined embossing pattern. Downstream of the embossing station (300), the machine (M) includes a demolding station (400) designed to demold the first web (N1) in accordance with a preferably non-circular predetermined three-dimensional shape.The machine (M) includes a winding station (500) in which the second web (N2) is wound in a tubular shape around the first embossed web (N1), and a cutting station (600) to divide the continuous tube profile (T) into tubular articles of predetermined length.

Description

Technical field

[0001] The present invention relates to a machine and a method for manufacturing tubular articles, in particular tubular profiles with inserts, for use as articles for the food industry or for smoking articles. State of the art

[0002] Machines for manufacturing tubular articles from two webs are known, each designed to define an outer shell and an inner insert of the tubular article. These machines are known, for example, from patent applications WO 2021 / 171186 and WO 2021 / 171187 filed on behalf of the applicant.

[0003] The known machines include a forming station in which the web defining the inner insert is formed, and a subsequent winding station in which the web defining the outer shell is wound around the inner web.

[0004] These machines also include a cutting station downstream of the winding station for dividing the continuous tube profile into tubular articles of predetermined length, which are fitted with an insert.

[0005] In known machines, at the point when the web defining the inner insert is wound, it is possible that the web, due to particularly stiff materials or special geometries of the insert to be obtained, is difficult to deform. This highlights the web's tendency to return to its original planar shape (elastic recovery). As a result, the insert is not formed as desired and can hinder the subsequent formation of the outer tube profile, which tends to detach from it, necessitating complex holding systems. Objective of the invention

[0006] The technical object of the present invention is therefore to provide a machine and a method for the production of tubular articles which are able to eliminate the disadvantages of the prior art.

[0007] The objective of the present invention is therefore to provide a machine and a method for the production of tubular articles that facilitate the deformation of the web that defines the application.

[0008] Another objective of the present invention is to provide a machine and a method for manufacturing tubular articles that achieve adequate shape stability of the end tube profile.

[0009] The stated technical problem and objectives are essentially achieved by a machine and a method for manufacturing tubular articles comprising the technical features set out in the attached claims 1 and 13 and / or in one or more of the dependent claims.

[0010] The applicant has determined that by applying a surface embossing to at least one of the two surfaces of the web that defines its application, a reduction in the web's flexural stiffness is achieved. This facilitates achieving the specified shape and reduces the web's tendency to elastically recover without altering the web's initial parameters (thickness, material, basis weight). This reduction in stiffness is achieved by combining surface engraving and transverse compaction (in the direction of thickness) during the embossing process, which causes the material to elongate in such a way as to reduce its flexural stiffness.In particular, the stated technical problem and objectives are essentially achieved by a machine for the production of tubular articles, especially for the food or tobacco industry, comprising: first feeding means for at least one first continuous web, designed to advance the at least one first continuous web along a first feed path; second feeding means for at least one second continuous web, designed to advance the at least one second continuous web along a respective second feed path, which converges with the first feed path towards an overlap area; and upstream of the overlap area, an embossing station designed to impart a permanent surface deformation on at least one side of the first continuous web in accordance with a predetermined embossing pattern.The term "embossing" can refer not only to an actual embossing process but also to a crimping process in which the embossing pattern is present on both sides and includes parallel grooves and / or protrusions.

[0011] Between the embossing station and the overlap area, the machine also includes a forming station designed to form the first web in accordance with a preferably non-circular predetermined three-dimensional shape.

[0012] Downstream of the overlap area, the machine includes a winding station in which the second web is wound around the first embossed web in a tubular shape, resulting in a continuous tubular profile in which the first formed web defines a continuous three-dimensional insert.

[0013] The machine also includes a cutting station downstream of the winding station for dividing the continuous tube profile into tubular articles of predetermined length.

[0014] The stated technical problem and objectives are further achieved by a method for manufacturing tubular articles for the food or tobacco industry, comprising a step for feeding at least one first continuous web along a first feed path, a step for feeding at least one second continuous web along a respective second feed path which converges with the first feed path to an overlap area, and a step for embossing the first continuous web in order to impart a permanent surface deformation on at least one side of the first continuous web in accordance with a predetermined embossing pattern.

[0015] The process further comprises a step for forming the first web in accordance with a preferably non-circular predetermined three-dimensional shape and a step for wrapping the second web around the first, embossed and formed web, thereby obtaining a continuous tube profile in which the first embossed web defines a continuous three-dimensional insert.

[0016] Preferably, the embossing is carried out on longitudinal strips of the first track, which are designed to obtain a final shape that is curved in section like the three-dimensional shape of the insert.

[0017] The process ultimately includes a step to cut the continuous tube profile in order to divide the continuous tube profile into tubular articles of predetermined length.

[0018] The stated technical problem and objectives are further achieved by a tubular article comprising a three-dimensional insert wrapped in an outer tubular profile, preferably with a circular cross-section. The insert has at least one curved area, which is embossed, particularly on the concave and / or convex side of the curved area.

[0019] Advantageously, the embossing of the track, which defines the inner insert of the continuous tube profile, facilitates the shaping of the insert and makes the tubular article more precise. Brief description of the drawings

[0020] Further features and advantages of the present invention will become clearer from the approximate and therefore non-limiting description of an embodiment of a machine and a method for manufacturing tubular articles and a tubular article in accordance with the invention.

[0021] This description is provided below with reference to the accompanying drawings, which are supplied solely as guidelines and are therefore not restrictive. They show: - Fig. 1 a schematic view of a machine according to the invention; - Fig. 2 an embodiment of an embossing station of the machine; - Fig. 3 a sectional view of an embossed web using an embossing station of the machine; - Fig. 3A a sectional view of another embodiment of an embossed web using an embossing station of the machine; - Fig. 4 A sectional view of a tubular article produced by the machine. Fig. 1 was manufactured; - Fig. 5 a sectional view of the tubular article during its forming in the machine Fig. 1. Detailed description of preferred embodiments of the invention

[0022] With reference to the accompanying figures, “M” designates a machine according to the invention for the production of tubular articles “A”, particularly for the food or tobacco industries. The tubular articles “A” according to the invention are obtained from two continuous webs, preferably made of paper. In particular, the tubular articles “A” are produced by cutting a continuous tube profile “T” which has a continuous three-dimensional insert “I” comprising a correspondingly shaped continuous first web “N1” and an outer coating produced by winding a second continuous web “N2” around the first continuous web “N1”, which has been previously shaped.

[0023] In other words, the first web “N1” is shaped to define a continuous three-dimensional insert “I”, around which the second continuous web “N2” is wound to form a continuous tube profile “T”, which is then cut to obtain the tubular articles “A”.

[0024] In the preferred embodiment, the first and second continuous webs “N1”, “N2” are made of paper material, however, it is possible that the materials used are different without changing the inventive concept of the present invention.

[0025] The machine “M” comprises first feeding means 100 for at least one first continuous path “N1” which are designed to advance the at least one first continuous path “N1” along a first feed path.

[0026] The machine “M” further comprises second feeding means 200 for at least one second continuous web “N2”, which are designed to advance the at least one second continuous web “N2” along a respective second feed path. The first and second feed paths converge towards an overlap area. Preferably, the first and second feeding means 100 and 200 respectively comprise spools from which the continuous webs “N1” and “N2” are unwound stepwise, and corresponding guide rollers arranged along the feed paths.

[0027] Alternatively, the first and second feed means 100, 200 comprise a single spool from which a single web is unwound, which is cut lengthwise into two strips defining the above-mentioned first and second continuous web “N1”, “N2”.

[0028] The machine “M” further comprises an embossing station 300 upstream of the overlap area, which is designed to impart a permanent surface deformation to at least one side of the first continuous web “N1” in accordance with a predetermined embossing pattern. The term “impart” refers to the application of a compaction by means of a shaped tool designed to create a partial engraving on the surface of the first web “N1,” such that the possibility of this compaction producing corresponding protrusions on the opposite surface does not result in a corresponding impression of the embossing on both sides. Instead, “embossing,” if present, is understood to mean that at least two tools are provided with this impression and are arranged facing the respective opposing surfaces of the first web “N1.”Preferably, the permanent surface deformation is carried out only on one side of the first track “N1”, and the permanent surface deformation is designed in such a way that it does not reach the opposite side of the first track “N1” itself.

[0029] In other words, the depth of the engravings made on the first track "N1" is less than the thickness of the first track "N1" itself. In this situation, one side of the first track "N1" is deformed, while the other side is preferably smooth and free of engravings. Preferably, the depth of the engravings made on the first track "N1" is less than half the thickness of the first track "N1" itself. In this way, even if opposing embossings are provided on the same strip of the first track "N1", no continuous engraving of the first track "N1" itself is obtained.

[0030] In one embodiment, the embossing pattern is defined by a sequence of parallel protrusions and / or recesses, in particular longitudinal or transverse (inclined or perpendicular).

[0031] In a preferred embodiment, the embossing pattern is defined by a sequence of longitudinal and parallel recesses, which are realized by an embossing surface provided with parallel projections. Such projections have, for example, a height between 0.05 mm and 0.2 mm, preferably approximately 0.1 mm, and a pitch of approximately 1 mm.

[0032] In another embodiment, the embossing pattern is a structured pattern defined by a sequence of protrusions and / or recesses arranged according to a two-dimensional arrangement on the surface of the first continuous track “N1”.

[0033] The term "embossing" can refer not only to an actual embossing process but also to a crimping process in which the embossing pattern is present on both sides and includes parallel grooves and / or protrusions, for example, such that the protrusions on one side overlap and are aligned with the grooves on the other side.

[0034] In accordance with the preferred embodiment, the embossing pattern is only present on one side of the first continuous web “N1”, while the other side of the first continuous web “N1” is free of this embossing pattern.

[0035] The embossing station 300 is designed to impart permanent surface deformation to one or more longitudinal belts “F1”, “F2” of the first track “N1”, which are adapted to define one or more respective curved sections of the three-dimensional insert “I”.

[0036] Preferably, the embossing station 300 is designed to impart the permanent surface deformation exclusively on one or more longitudinal belts “F1”, “F2” of the first track “N1”, which are adapted to define one or more respective curved sections of the three-dimensional insert.

[0037] In other words, in the embossing station 300, the first web “N1” is superficially deformed in areas which, after the first web “N1” has been formed, are themselves curved by subsequent stations of the machine “M”, as described below.

[0038] In detail, the embossing station 300 is preferably designed to impart the permanent surface deformation on the side of each of the longitudinal bands “F1”, “F2”, which is intended to assume a concave design when the forming process is complete.

[0039] However, it is within the scope of the invention to arrange this embossing pattern on the side of each of the longitudinal bands “F1”, “F2” which is intended to assume a convex shape when the forming process is complete.

[0040] According to one aspect of the present invention, the embossing station 300 comprises a pair of rollers 300a, 300b which are opposite to each other in order to define a through gap between them for the first continuous web “N1”.

[0041] At least one of the rollers 300a, 300b has an embossed surface on the outside.

[0042] In other words, at least one of the rollers 300a, 300b has a knurled, textured or recessed / cut-out outer surface that defines the embossing pattern to be pressed onto the first web “N1”.

[0043] Preferably, the pair of rollers 300a, 300b comprises a pressure roller with a smooth peripheral surface and an embossing roller with a peripheral surface provided with a knurled or textured pattern. The pressure roller is designed to press the first web “N1” against the embossing roller to imprint a pattern on the first web “N1” that corresponds to the pattern of the outer surface of the embossing roller. The two rollers (or more generally, the two printing surfaces) are preferably made of steel.

[0044] In use, the first web “N1” is guided between the rollers 300a, 300b, so that the pressure roller presses the first web “N1” against the embossing roller, so that the embossing pattern, which corresponds to the pattern of the outer shell of the embossing roller, is pressed onto it.

[0045] The embossing station 300 can also be designed to impart permanent surface deformation to both sides of the first track “N1”.

[0046] In the illustrated embodiment, the embossing station 300 imparts the permanent surface deformation to both sides of the first track “N1”. In particular, the embossing station 300 imparts a first surface deformation to two lateral longitudinal bands “F2” on one side of the first track “N1”, while it imparts a second surface deformation to a central longitudinal band “F1” on the other side of the first track “N1”.

[0047] In other words, the embossing station 300 can be designed to impart permanent surface deformation on both sides of the first track “N1”, but in separate areas, in particular on separate longitudinal strips, such that one or more first longitudinal strips have an embossing on one side and one or more second longitudinal strips, which are separate or at least partially separate from the first, have an embossing on the other side.

[0048] In the Fig. In the embodiment shown in Figure 3 (in which the first embossed track “N1” is shown), the embossing station 300 is designed to impart surface deformation to longitudinal strips “F1”, “F2” of the first track “N1” which are separated from each other, such that one or more first longitudinal strips “F1” have an embossing only on one side and one or more second longitudinal strips “F2”, which are separated or at least partially separated from the first longitudinal strips “F1”, have an embossing only on the other side.

[0049] According to another variant, the embossing station 300 can be designed to impart the permanent surface deformation on both sides of the first track “N1” on the same belts, in particular on the belts which are intended to assume a curvature after the forming process is complete.

[0050] For example, in Fig. As shown in Figure 3A (in which the first embossed track “N1” is shown), the embossing station 300 is designed to impart the permanent surface deformation to one or more longitudinal bands “F” of the first track “N1” such that the at least one longitudinal band “F” has the embossing on both sides. In particular, the embossing station 300 is designed to exert an engraving effect on the first track “N1” on both sides of the at least one longitudinal band “F”.

[0051] In this situation, the surface deformations that are carried out on two sides of the first web “N1” are carried out with two different embossing tools, e.g. rollers 300a, 300b, which are opposite to each other and act simultaneously on the first web “N1” or are arranged in sequence so that they act one after the other on the first web “N1”.

[0052] Alternatively, the embossing station 300 and in particular one embossing tool thereof could impart a surface deformation effect so intensely on at least one longitudinal belt “F” of the first track “N1” that protrusions are created on the side opposite the one on which this embossing tool acts.

[0053] In other words, the embossing tool acting on one side of the at least one longitudinal band “F” of the first track “N1” could impart a surface deformation so severe that it will cause protrusions to form on the side of the at least one longitudinal band “F” of the first track “N1” opposite the side on which the embossing tool acts. According to another variant, the embossing station 300 can be designed to impart the permanent surface deformation substantially over the entire surface on one side of the first track “N1”, where “substantially” means at least 90% of the surface.

[0054] According to another variant, the embossing station 300 can be designed to impart the permanent surface deformation substantially over the entire surface of both sides of the first track “N1”, where “substantially” means at least 90% of the surface.

[0055] The Fig. 3 and Fig. Figure 4 shows a specific solution in which the first web “N1” receives an embossing pattern on one or more first longitudinal bands “F1” on one side, which are located in the middle, and on second longitudinal bands “F2” on the other side, in particular side bands. These longitudinal bands “F1”, “F2” define respective curved sections of the three-dimensional insert “I” ( Fig. 4) In particular, in Fig. 4 the first path “N1” is formed to create an insert “I” which has an “Ω” shape in cross-section, i.e. a shape in which a curved section “P1” (with inverted “U”) is inserted between two lateral sections “P2” which are determined to be curved (as described below together with the second path “N2”) to assume a concavity opposite to that of the curved section “P1”.

[0056] In this situation, the embossing station 300 could comprise a (single) pair of rollers 300a, 300b, wherein one roller 300a has a peripheral shell that has knurling or shaping only on the side sections in order to impress a corresponding pattern onto the lateral longitudinal bands “F2” on one side of the first web “N1” (i.e., on the longitudinal bands corresponding to the lateral sections “P2” of the insert “I”). The other roller 300b of the pair instead has a peripheral shell that has knurling or shaping only on the central section in order to impress a corresponding pattern onto the central longitudinal band “F1” on the other side of the first web “N1” (i.e., on the longitudinal band corresponding to the curved section “P1” of the insert “I”).

[0057] In this situation, when the first web “N1” passes through the two rollers 300a, 300b, the lateral longitudinal strips “F2” on one side are embossed simultaneously with the central longitudinal strip “F1” on the other side, resulting in an embossing like the one in Fig. The 3 shown will be obtained. Alternatively, the minting station 300 could be used to produce a coin like the one shown. Fig. To obtain 3 shown, a first pair of rollers 300a', 300b' and a second pair of rollers 300a'', 300b'' are to be included, the rollers being arranged one after the other along the first feed path ( Fig. 2).

[0058] The first pair of rollers 300a', 300b' has a roller 300a' that is arranged above the first web "N1" and is provided with a peripheral shell having a knurled or textured pattern, and a roller 300b' that is arranged below the first web "N1" having a smooth peripheral shell.

[0059] The peripheral shell of the roller 300a' (arranged above the first web "N1") is designed such that it only imprints a pattern on the two lateral longitudinal bands "F2" of the first web "N1", which corresponds to the pattern of the shell itself, i.e. on the longitudinal bands "F1", "F2", which correspond to the lateral sections "P2" of the insert "I" ( Fig. 3).

[0060] The second pair of rollers, 300a'', 300b'', comprises a roller 300a'' positioned above the first web "N1" and provided with a smooth peripheral surface, and a roller 300b'' positioned below the first web "N1" and having a peripheral surface with a knurled or textured pattern. In this configuration, the surface deformation occurs on the side of the first web "N1" opposite the side where the surface deformation was performed by the first pair of rollers 300a', 300b'. The peripheral surface of the roller 300b positioned below the first web "N1" is designed such that the pattern, corresponding to that of the surface itself, is pressed only onto a central longitudinal band "F1," which defines the curved section "P1" of the insert "I".

[0061] In this situation, the first continuous web “N1” is guided through the embossing station 300. In this way, the first web “N1” undergoes an initial surface deformation by the first pair of rollers 300a', 300b'. This first pair of rollers 300a', 300b' imprints a predetermined embossing pattern on one side of the first web “N1”, more precisely along the two lateral longitudinal bands “F2” of the first web “N1”.

[0062] The first web “N1” then undergoes a second surface deformation by the second pair of rollers 300a'', 300b''. This second pair of rollers 300a'', 300b'' imprints a predetermined embossing pattern on the other side of the first web “N1”, more precisely along the central longitudinal band “F1” of the first web “N1”.

[0063] At the exit of embossing station 300, the first track “N1” has a flat position and is embossed on both sides ( Fig. 2 and Fig. 3).

[0064] According to one aspect of the present invention, the machine “M” comprises a movement mechanism that is active on at least one of the rollers 300a, 300b of the embossing station 300 to effect and / or enable a mutual movement for approaching and moving away between the rollers 300a, 300b in order to vary the through-gap and / or a crushing pressure of the rollers 300a, 300b (in the first and second pair of rollers 300a', 300b', 300a'', 300b'', at least one roller per pair could be provided with the movement mechanism).

[0065] The term "bring about" refers to an active attitude, while the term "enable" refers to at least a partially passive attitude (e.g., simple compliance).

[0066] Preferably, the movement mechanism allows one of the two rollers 300a, 300b to be moved closer to or further away from the other in order to vary the size of the transmitted light, i.e., it allows an active adjustment of the relative position of the rollers 300a, 300b.

[0067] Preferably, the movement mechanism allows for passive adjustment of the rollers 300a, 300b, either as an alternative or in addition to active adjustment. This passive adjustment can be achieved, for example, by mounting one of the two rollers 300a, 300b by means of at least one elastic support (springs or spring elements) which is compressed or stretched depending on whether the roller 300a, 300b is pressed against or moved away from the other roller 300a, 300b. For example, if the first web “N1” has a thickness greater than a web previously processed by the machine “M”, or if a temporary increase in the thickness of the processed web occurs when it passes through the through-gap, this leads to a separation of the two rollers 300a, 300b.In this situation, the spring-connected roller 300a, 300b moves away from the other roller 300a, 300b, thereby adjusting itself to the new thickness while maintaining an appropriate embossing pressure. Conversely, if the first web “N1” has a thinner web than a web previously processed by machine “M”, or if a temporary reduction in the thickness of the processed web occurs as it passes through the through-gap, the two rollers 300a, 300b move closer together. In this situation, the spring-connected roller 300a, 300b moves closer to the other roller 300a, 300b, thereby adjusting itself to the new thickness while maintaining an appropriate embossing pressure.

[0068] In accordance with one possible embodiment, the movement mechanism can be actively operated based on the processing of one or more data points acquired by one or more sensors located downstream of the embossing station 300. These sensors are designed to monitor one or more parameters relating to the embossing status of the first web "N1" (e.g., embossing depth, extent and position of the embossing areas, embossing quality) or to the original web parameters (thickness, width, material type – paper – and others). In this scenario, the signals from the sensors are sent to a control unit, which processes them and, based on this processing, sends a command to the movement mechanism to adjust the relative positions of rollers 300a and 300b.

[0069] The machine “M” further comprises between the embossing station 300 and the overlap area a forming station 400, which is designed to form the first web “N1” in accordance with a preferably non-circular predetermined three-dimensional shape.

[0070] Within the scope of the present invention, the specific shape does not constitute a limitation of the invention, although an exemplary, non-limiting shape is shown in the accompanying figures. In particular, as already mentioned, the shape in the accompanying figures has a substantially “Ω” shape.

[0071] In accordance with a preferred embodiment, the forming station 400 comprises a guide rail 401 around which the first continuous web “N1” is at least partially formed and / or guided. This guide rail 401 defines a core around which the first continuous web “N1” is advanced.

[0072] In this situation, the first track “N1” is deformed such that the embossed central longitudinal band “F1” defines the curved section “P1” (with inverted “U”) of the insert “I”.

[0073] Preferably, in order to prevent an elastic return of the first continuous path “N1”, the guide rail 401 can interact with a pair of guide elements (not shown), which are realized, for example, in the form of rods or metal blocks that develop parallel to the first feed path and interact with the guide rail 401 to keep the first path “N1” in the position wound around it.

[0074] Following the guide elements (if present), the forming station 400 also includes a pair of forming elements that are opposite to each other and work together with the guide rail 401 to carry out a permanent shaping of the first continuous path “N1”.

[0075] Preferably, the forming elements comprise two fixed bending devices designed to bring the lateral longitudinal bands “F2” of the first continuous web “N1” closer together.

[0076] The shape elements drive the lateral longitudinal bands “F2” of the first continuous path “N1” towards each other, so that the cross-section of the first path “N1” essentially assumes the “Omega” shape (“Ω”).

[0077] In the preferred embodiment, before or at the forming station 400, the machine “M” comprises a preforming station 700, which is designed to impart a localized deformation on the first web “N1” in order to execute at least one pre-bend longitudinal line such that in the forming station 400 the first web “N1” is bent or deformed about the at least one pre-bend longitudinal line to assume the formed final design.

[0078] The at least one pre-bending longitudinal line preferably corresponds to a longitudinal bending edge of the insert “I”.

[0079] In other words, the preforming station 700 ensures that longitudinal weakening lines are pressed into the first web "N1", around which the first web "N1" is bent in the forming station 400. These longitudinal lines define the respective edges of the insert "I". Preferably, the preforming station 700 comprises at least one engraving wheel 701 designed to define each pre-bend longitudinal line. This wheel has a peripheral edge that, when pressed against the first web "N1", is suitable for defining at least a partially permanent indentation along a line, thereby defining a reduction in bending strength along this line. In the preferred embodiment, the preforming station 700 comprises two engraving wheels 701 designed to define each pre-bend longitudinal line to define the two edges of the insert "I".

[0080] More precisely, in the preferred embodiment, the engraving wheels 701 are designed such that they define respective pre-bending longitudinal lines near the lateral longitudinal bands “F2” of the first track “N1”. In this situation, when the first track “N1” is wrapped around the guide rail 401 and passes through the fixed bending devices, these latter lie along the formed pre-bending longitudinal lines and thereby define the edges of the insert “I”, i.e., define the edges of the “Ω” shape.

[0081] In the specific embodiment of the Fig. 5 the preforming station 700 (engraving wheels 701) is arranged parallel to the guide rail 401, however it could be arranged in front of the guide rail 401 and perform the engraving on a planar design of the first track “N1”.

[0082] According to one aspect of the present invention, the at least one engraving wheel 701 can be configured to define a respective pre-cut longitudinal line. This wheel has a peripheral rim suitable for defining a pre-cut (throughout the entire thickness or discontinuously) along a longitudinal line when pressed against the first track “N1”. Preferably, the pre-cut line is discontinuous, i.e., along the longitudinal line, forming cut / engraved portions that are divided into respective uncut / engraved portions.

[0083] In other words, at least one engraving wheel 701 can be designed to create a sequence of pre-cuts along the longitudinal line on the first track “N1”.

[0084] As shown in the attached figures, downstream of the forming station 400 in the overlap area, the first and second feed paths are joined together in such a way that some sections of the first formed path “N1” overlap with respective sections of the second continuous path “N2”.

[0085] This overlap occurs at pre-glued areas of the first and / or second web “N1”, “N2”. In particular, the gluing is preferably carried out on the second continuous web “N2”, in front of the overlap area.

[0086] For gluing the webs “N1”, “N2”, the machine “M” includes a gluing device 800, which is arranged upstream of the overlap area along the first and / or second feed path and is designed so that at least one longitudinal glue line is applied to the first and / or second web “N1”, “N2”.

[0087] In the embodiment shown in the accompanying figures, the gluing device 800 applies two longitudinal (and parallel) glue lines to the second continuous track “N2” to define two gluing areas adapted to obtain the lateral sections “P2” of the “Ω”-shaped insert “I”. In this situation, the second continuous track “N2” is in a flat configuration and is positioned below the first track “N2” so that it is in contact with the first track “N1”.

[0088] Preferably, the glue lines are applied at different positions in relation to the positions corresponding to the embossed sections of the first web “N1” and / or the edges.

[0089] Downstream of the overlap area, the machine “M” includes a winding station 500 in which the second web “N2” is wound tubularly around the first web “N1”, resulting in a continuous tube profile “T” in which the first formed web “N1” defines the continuous three-dimensional insert “I”.

[0090] In the illustrated embodiment, during winding, the side sections “P2” of the insert “I”, which are glued onto the second web “N2”, are curved together with the second web “N2”, thereby defining respective curved sections of the three-dimensional insert “I”. In this situation, the three-dimensional insert “I” has the two side sections “P2” that are convex opposite the curved section “P1” and are embossed on the side opposite the curved section “P1”.

[0091] As shown in the attached figures, the machine “M” additionally includes a cutting station 600 downstream of the winding station 500 to divide the continuous tube profile “T” into tubular articles “A” of predetermined length.

[0092] The present invention further relates to a tubular article “A” comprising a three-dimensional insert “I” which is wrapped in an outer tubular profile, preferably with a circular cross-section. Preferably, the insert “I” is made of paper material.

[0093] The insert “I” has at least one embossed curvature area, in particular on the concave and / or convex side of the curvature area.

[0094] Preferably, the insert “I” has at least one flat longitudinal band that is free of embossing.

[0095] Preferably, the insert “I” has a three-dimensional profile comprising at least a first and at least a second region, which are consecutive and have opposite curvatures, wherein the first region has an embossing that is executed on at least one first side of the first track “N1”, and the second region has an embossing that is executed on at least one second side of the first track “N1”, which is opposite the first side. Therefore, in this case, preferably the two embossings are executed on respective concave surfaces of the insert “I” or, alternatively, both are executed on respective convex surfaces of the insert “I”.As an alternative to this solution, the insert “I” has a three-dimensional profile which has at least one first and at least one second area which are consecutive and have opposite curvature, wherein both the first area and the second area have an embossing on both sides.

[0096] The present invention further relates to a method for producing a tubular article “A” for the food or tobacco industry.

[0097] The tubular articles “A” according to the invention are obtained from two continuous webs, preferably made of paper. In particular, the tubular articles “A” are produced by cutting a continuous tube profile “T” which has a continuous three-dimensional insert “I” comprising a correspondingly shaped continuous first web “N1” and an outer coating produced by winding a second continuous web “N2” around the first continuous web “N1”, which has been previously shaped.

[0098] The process comprises a step for feeding at least one first continuous path "N1" along a first feed path and a step for feeding at least one second continuous path "N2" along a respective second feed path. The first and second feed paths converge towards an overlap region.

[0099] The process also includes a step for embossing the first continuous track “N1” to impart a permanent surface deformation on at least one side of the first continuous track “N1” in accordance with a predetermined embossing pattern. Preferably, the embossing step is carried out on longitudinal bands “F1”, “F2” of the first track “N1” that correspond to one or more curvature regions of the continuous three-dimensional insert “I”, in particular on the concave and / or convex side of the curvature regions.

[0100] In the illustrated embodiment, during the embossing step, the first track “N1” is embossed on one side on lateral longitudinal bands “F2” and on the other side on at least one central longitudinal band “F1” ( Fig. 3).

[0101] The method also includes a step to shape the first track “N1” in accordance with a preferably non-circular predetermined three-dimensional shape, for example (but not limited to) an “Ω” shape, in order to define the three-dimensional continuous insertion “I”.

[0102] In the illustrated embodiment, the first track “N1” is bent such that the lateral longitudinal bands “F2” define side sections “P2” of the insert “I”, while the central longitudinal band “F1” defines a curved section “P1” ( Fig. 4) defined, which has a curvature opposite to that of the side sections “P2”.

[0103] The process further includes a step for wrapping the second sheet “N2” around the first embossed and formed sheet “N1”, thereby obtaining a tubular continuous tube profile “T” in which the first embossed sheet “N1” defines the continuous three-dimensional insert “I”. The side sections “P2” of the insert “I” can adhere completely to the inner surface of the outer tube profile obtained by the second sheet “N2”.

[0104] The process then includes a step to cut off the continuous tube profile “T” in order to divide the continuous tube profile “T” into tubular articles “A” of predetermined length.

[0105] This invention fulfills the underlying objectives by eliminating the disadvantages of the prior art.

[0106] In particular, the embossing of the first continuous track “N1”, i.e. the track intended to form the insert “I”, makes the forming of the insert “I” easier and simpler.

[0107] The embossing actually facilitates the bending of the insert “I” and makes it possible to obtain tubular articles “A” with a stable shape, the shaping of which is particularly easy. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2021 / 171186

[0002] WO 2021 / 171187

[0002]

Claims

[1] Machine (M) for the manufacture of tubular articles (A), in particular for the food or tobacco industry, comprising: - first feeding means (100) for at least one first continuous path (N1) designed to advance the at least one first continuous path (N1) along a first feed path; - second feeding means (200) for at least one second continuous path (N2) designed to advance the at least one second continuous path (N2) along a respective second feed path, wherein the first and second feed paths converge towards an overlap area; - downstream of the overlap area an embossing station (300) designed to impart a permanent surface deformation on at least one side of the first continuous web (N1) in accordance with a predetermined embossing pattern; - between the embossing station (300) and the overlap area a forming station (400) which is designed to form the first web (N1) in accordance with a preferably non-circular predetermined three-dimensional shape; - downstream of the overlap area a winding station (500) in which the second web (N2) is wound tubularly around the first embossed web (N1), thereby obtaining a continuous tubular profile (T) in which the first formed web (N1) defines a continuous three-dimensional insert (I); - a cutting station (600) located downstream of the winding station (500) to divide the continuous tube profile (T) into tubular articles of predetermined length. [2] Machine according to claim 1, wherein the embossing station (300) is designed to impart the permanent surface deformation on one or more longitudinal strips (F1, F2) of the first web (N1) adapted to define one or more respective curved sections of the three-dimensional insert, preferably exclusively on one or more longitudinal strips (F1, F2) of the first web (N1) adapted to define one or more respective curved sections of the three-dimensional insert (I). [3] Machine according to claim 2, wherein the embossing station (300) is designed to impart the permanent surface deformation on the concave side of each of the longitudinal strips (F1, F2). [4] Machine according to claim 2, wherein the embossing station (300) is designed to impart the permanent surface deformation on both sides of the first web (N1). [5] Machine according to claim 4, wherein the embossing station (300) is designed to impart surface deformation to longitudinal strips (F1, F2) of the first web (N1) that are separated from each other, such that one or more first longitudinal strips (F1) have an embossing only on one side and one or more second longitudinal strips (F2) that are separated or at least partially separated from the first longitudinal strips (F1) have an embossing only on the other side. [6] Machine according to claim 4, wherein the embossing station (300) is designed to impart permanent surface deformation on one or more longitudinal strips (F) of the first track (N1) such that the at least one longitudinal strip (F) has an embossing on both sides, wherein in particular the embossing station (300) is designed to exert an engraving effect of the first track (N1) on both sides of the at least one longitudinal strip (F). [7] Machine according to one of the preceding claims, wherein the embossing station (300) is designed to impart the permanent surface deformation substantially over an entire surface of at least one side of the first web (N1), preferably over at least 90% of the surface. [8] Machine according to one of the preceding claims, wherein the embossing pattern is defined by a sequence of parallel projections and / or recesses, in particular longitudinal or transverse. [9] Machine according to any one of the preceding claims 1 to 4, wherein the embossing pattern is a structured pattern defined by a sequence of protrusions and / or recesses arranged in a two-dimensional arrangement on the surface of the first continuous web (N1). [10] Machine according to one of the preceding claims, wherein the embossing station (300) comprises a pair of rollers (300a, 300b) which are opposite to each other in order to define a through gap between them for the first continuous web (N1), wherein at least one of the rollers (300a, 300b) is provided on the outside with an embossing surface. [11] Machine according to claim 10, wherein the pair of rollers (300a, 300b) comprises a pressure roller with a smooth peripheral shell and an embossing roller with a peripheral shell provided with a knurled or textured pattern, wherein the pressure roller is designed to press the first continuous web (N1) against the embossing roller in order to obtain on at least one section of the first continuous web (N1) a pattern corresponding to the pattern of the outer shell of the embossing roller. [12] Machine according to claim 10 or 11, comprising a movement mechanism active on at least one of the rollers (300a, 300b) to effect and / or enable mutual movement to approach and distance between the rollers (300a, 300b) in order to vary the through gap and / or a crushing pressure of the rollers (300a, 300b). [13] Machine according to one of the preceding claims, comprising, upstream of the forming station (400), a preforming station (700) which is designed to impart a localized deformation on the first web (N1) in order to execute at least one pre-bend longitudinal line such that in the forming station (400) the first web (N1) is bent or deformed around the at least one pre-bend longitudinal line to assume the formed design. [14] Machine according to claim 13, wherein the at least one pre-bending longitudinal line corresponds to a longitudinal bending edge of the insert (I). [15] Machine according to claim 13 or 14, wherein the preforming station (700) comprises at least one engraving wheel (701) designed to define a respective pre-bending or pre-cutting longitudinal line, wherein the pre-bending or pre-cutting longitudinal line is continuous or interrupted. [16] Method for the manufacture of tubular articles (A), in particular for the food or tobacco industries, comprising the following steps: - Feeding at least one first continuous path (N1) along a first feed path; - Feeding at least one second continuous path (N2) along a respective second feed path, wherein the first and second feed paths converge towards an overlap area; - Embossing the first continuous web (N1) to impart a permanent surface deformation on at least one side of the first continuous web (N1) in accordance with a predetermined embossing pattern; - Forming the first track (N1) in accordance with a preferably non-circular predetermined three-dimensional shape; - Wrapping the second web (N2) around the first embossed and formed web (N1), thereby obtaining a continuous tube profile (T) in which the first embossed web (N1) defines a continuous three-dimensional insert (I); - Cutting off the continuous tube profile (T) to divide the continuous tube profile (T) into tubular articles (A) of predetermined length. [17] Method according to claim 16, wherein the embossing step is carried out on longitudinal strips of the first web (N1) which correspond to one or more curvature regions of the continuous three-dimensional insert (I), in particular on the concave and / or convex side of the curvature regions. [18] Method according to claim 16 or 17, wherein the continuous three-dimensional insert (I) has at least one flat longitudinal band and wherein the embossing step is carried out such that the insert (I) has no embossing on the at least one flat longitudinal band. [19] Tubular article (A) comprising a three-dimensional insert (I) which is wrapped in an outer tubular profile, preferably with a circular cross-section, wherein the insert (I) has at least one curved area which is provided with embossing, in particular on the concave and / or convex side of the curved area. [20] Tubular article according to claim 19, wherein the insert (I) has at least one flat longitudinal band and wherein the at least one flat longitudinal band is free from embossing. [21] Tubular article according to claim 19 or 20, wherein at least the insert (I) is made of paper material.

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