A machine and method for manufacturing a continuous rod for the tobacco industry

Abstract

A machine (M) for manufacturing a continuous rod (T) for the tobacco industry, comprising first feeding means (100) for feeding a continuous web (N) configured to advance a continuous web (N) along a first advancement path, and second feeding means (200) for feeding a filling material (R). The machine (M) further comprises a winding station (300) to perform a progressive winding of the continuous web (N) in a tubular shape about the filling material (R). The machine (M) comprises a first and second gluing devices (400, 600) configured to apply a cold adhesive and arranged one along the first advancement path upstream of the joining zone (U) and one downstream of the joining zone (U), respectively. The machine (M) further comprises a control unit (C) connected to the first and second gluing devices (400, 600) and configured to selectively activate the first and second gluing devices (400, 600) based on a speed parameter of the machine (M).

Description

[0001] DESCRIPTION

[0002] A MACHINE AND METHOD FOR MANUFACTURING A CONTINUOUS ROD FOR THE TOBACCO INDUSTRY

[0003] Technical field

[0004] The present invention relates to a machine and a method for manufacturing a continuous rod for the tobacco industry.

[0005] The rod is obtained from a material, conventionally a web material, preferably paper, which is wound to form an outer tubular piece in which a filling material is arranged.

[0006] In particular, the continuous rod obtained in the context of the present invention can be used (after cutting) to form a series of segments adapted to be used in products of the tobacco industry, such as cigarettes or aerosol generators (i.e., products of the heat-not-burn type in which at least one plug is intended to be heated in order to produce aerosols). In particular, the segments obtained by cutting the continuous rod obtained in the context of the present invention can have a filtering function and / or a cooling function and / or a spacing function and / or a retaining function and / or an aerosol generating function.

[0007] Note that the term products of the tobacco industry is not understood to mean products exclusively containing tobacco; indeed, tobacco-free (and / or nicotine-free) products are also included, which are intended to be part of products smoked / inhaled by a user.

[0008] Background art

[0009] As is known, in order to manufacture a continuous rod for the tobacco industry, an adhesive substance is applied to a first side portion of a continuous web and the latter is wound about the filling material so that the first side portion surmounts a second side portion of the continuous web, opposite to the first side portion, forming a closed winding with longitudinal junction. In such a situation, the need is particularly felt to use an adhesive substance that ensures a sufficiently quick and strong adhesion between the first and second side portions so as to limit the thrust exerted by the filling material inside the tubular piece on the tubular piece itself.

[0010] Collecting the filling material by means of converging devices, which result in an at least partially elastic transverse compression of the filling material, is known. Once the tubular piece has been wound about the filling material, the latter tends to exert an elastic return thrust on the tubular piece, which could cause the reopening of the longitudinal joining, by means of the first side portion separating from the second side portion, and therefore an opening of the tubular piece.

[0011] Furthermore, the continuous web, which is wound to form the tubular piece, also tends to reopen due to its nature. In particular, such an issue becomes even greater the higher the weight of the continuous web employed to form the tubular piece is, since it is rather rigid and it could be complex to make the side portions thereof adhere in a short time.

[0012] To date, the most commonly used adhesive substance is a glue of the “hot- melt” type, i.e. , a hot glue, known for the quick setting properties thereof. In such a situation, once the first side portion overlaps the second side portion, the hot glue is cooled and almost immediately exerts the adhesive action thereof while keeping the tubular piece in a stably closed form. Therefore, said glue of the “hot-melt” type ensures a sufficiently quick and strong adhesion (such as not to affect the machine speed) between the side portions of the web.

[0013] However, such a glue of the “hot-melt” type is not biodegradable. Therefore, said glue is not usable for manufacturing continuous tubular pieces with filling adapted to define biodegradable products.

[0014] To date, in order to obviate the problem of biodegradability, a cold glue could be used (e.g., a relatively thick paste, such as starch glues or waterbased glues, such as PVA or EVA glue).

[0015] However, said water-based glue needs to be dried in order to set and has relatively long drying times to ensure a sufficiently strong sealing of the tubular piece against the elastic return thrust exerted by the filling material or by the continuous web.

[0016] Such relatively long times for drying the cold glue are poorly suited to the high production speed features of the machines for manufacturing the aforesaid types of continuous rod.

[0017] Disclosure of the invention

[0018] In this context, it is the technical task underlying the present invention to suggest a machine and a method for manufacturing a continuous rod for the tobacco industry, which overcome the aforesaid drawbacks of the prior art.

[0019] In particular, it is the object of the present invention to provide a machine and a method for manufacturing a continuous rod for the tobacco industry, having high production speeds while ensuring an end product in which the web forming the tubular piece remains closed over time and does not tend to open.

[0020] It is a further object of the present invention to provide a machine and a method for manufacturing a continuous rod for the tobacco industry, capable of producing a continuous rod in which the thrust deriving from the filling material is effectively opposed.

[0021] It is a further object of the present invention to provide a machine and a method for manufacturing a continuous rod for the tobacco industry, capable of producing a biodegradable continuous rod.

[0022] The specified technical task and the specified objects are substantially achieved by a machine and a method for producing a continuous rod for the tobacco industry comprising the technical features set out in the appended claims.

[0023] In particular, the specified technical task and the specified objects are achieved by a machine for manufacturing a continuous rod for the tobacco industry in accordance with the present invention.

[0024] The machine comprises first feeding means for feeding a continuous web configured to advance a continuous web along a first advancement path and second feeding means for feeding a filling material configured to advance the filling material along a second advancement path. The first and second advancement paths converge towards a joining zone.

[0025] Preferably, the filling material is a continuous web comprising, for example, a cellulose-based material or PLA or non-woven fabric or a combination thereof. Alternatively, the filling material could not be in the shape of a web. As a further alternative, the filling material could comprise tobacco. For example, the filling material could be in the shape of a continuous web comprising a tobacco-based material or a nicotine-containing substrate or an aerosol generator.

[0026] The machine further comprises a winding station configured to progressively wind the continuous web in a tubular shape about the filling material thus obtaining a continuous rod.

[0027] Preferably, the winding station has a forming section configured to deform the continuous web into a curved shape about a longitudinal axis and a subsequent closing section configured to close the continuous web in a tubular shape by securing opposing edges of the continuous web.

[0028] The machine further comprises a first gluing device arranged along the first advancement path and upstream of the joining zone, configured to apply the cold adhesive at a first band, in particular the side band, of the continuous web.

[0029] The first band (side band) defines a longitudinal junction zone, in particular by overlapping, of the continuous rod.

[0030] The machine further comprises a second gluing device arranged downstream of the joining zone, configured to apply a cold adhesive at the first band (side band) of the continuous web.

[0031] In accordance with an embodiment, the second gluing device is arranged in the forming section of the winding station to apply the at least one cold adhesive to the first band of the continuous web, in particular while the first band is inclined with respect to the rest of the continuous web.

[0032] In accordance with an alternative embodiment, the second gluing device is arranged upstream of the winding station to apply the at least one cold adhesive to the first band of the continuous web, in particular while the continuous web lies flat.

[0033] Preferably, the first and second gluing devices are configured to apply at least one line of adhesive at the first band of the continuous web.

[0034] Preferably, the first and second gluing devices are configured to apply the same number of lines of adhesive.

[0035] Preferably, the machine further comprises a heating device arranged downstream of the winding station and configured to operate a heating of the adhesive released by one of the first gluing device and the second gluing device.

[0036] Preferably, the machine further comprises a control unit connected to the first and second gluing devices and configured to selectively activate the first and second gluing devices based on a speed parameter of the machine, in particular the advancement speed of the continuous web along the first advancement path.

[0037] Preferably, the control unit is configured to activate the first gluing device if the speed parameter is above a threshold value and to activate said second gluing device if the speed parameter is below said threshold value. Preferably, the threshold value is between 100 m / min and 350 m / min, more preferably between 150 m / min and 300 m / min, and even more preferably between 200 m / min and 250 m / min.

[0038] Preferably, the control unit is configured to receive the speed parameter of the machine, in particular by means of an input interface.

[0039] Alternatively, the control unit is configured to detect the speed parameter of the machine by means of at least one sensor applied to the machine, preferably an angular encoder.

[0040] Alternatively, the control unit is configured to load the speed parameter of the machine from a database for setting the machine or from a current configuration set for the machine.

[0041] Preferably, the control unit is configured to selectively activate the first and second gluing devices also based on at least one additional parameter.

[0042] Preferably, the additional parameter is selectable from:

[0043] - a physical property of the cold adhesive applied by the first or second gluing device;

[0044] - a physical property of the continuous web.

[0045] In accordance with a possible embodiment, the machine further comprises at least one pre-heating device arranged upstream of the heating device and configured to operate a pre-heating of the at least one adhesive released by one of the first gluing device and the second gluing device and / or of the first band of said continuous web intended to receive said adhesive.

[0046] Preferably, the machine comprises a first preheating device arranged upstream of the joining zone, in particular arranged in a position between the first gluing device and the joining zone, configured to operate a preheating of the adhesive released by the first gluing device.

[0047] In addition or alternatively to the first preheating device, the machine can comprise a second pre-heating device arranged downstream of the joining zone, in particular arranged in a position between the joining zone and the winding station, configured to operate a pre-heating of the adhesive released by the second gluing device.

[0048] Preferably, each of the pre-heating devices is configured to operate a preheating of the adhesive released by the respective gluing device.

[0049] In such a situation, the control unit is configured to selectively activate the first gluing device and the first pre-heating device or the second gluing device and the second pre-heating device.

[0050] Preferably, the control unit is configured to vary the amount of energy emitted by the first pre-heating device and / or the second pre-heating device between a minimum value and a maximum value, in particular based on a value of the operating parameter. In detail, the specified technical task and the specified objects are achieved by a method for manufacturing a continuous rod for the tobacco industry in accordance with the present invention.

[0051] Preferably, the method is varied out by means of a machine in accordance with the above description.

[0052] The method comprises a step of advancing a continuous web along a first advancement path and a step of advancing a filling material along a second advancement path converging with the first advancement path in a joining zone.

[0053] The method further comprises a step of applying at least one cold adhesive to the continuous web at a first band, in particular, a side band of the continuous web.

[0054] The step of applying the at least one cold adhesive at the first band of the continuous web is operable by means of a first gluing device, arranged along the first advancement path upstream of the joining zone, or by means of a second gluing device, arranged downstream of the joining zone.

[0055] Both gluing devices are simultaneously present.

[0056] The step of applying the at least one cold adhesive comprises a sub-step of selectively activating one of the gluing devices based on a speed parameter of the machine, in particular, the advancement speed of the continuous web.

[0057] The method further comprises a step of progressively winding the continuous web in a tubular shape about the filling material, thus obtaining a continuous rod.

[0058] The step of winding comprises a sub-step of deforming the continuous web into a curved shape about a longitudinal axis and a sub-step of securing the opposing edges of the continuous web, defining a longitudinal junction zone of the continuous rod.

[0059] Preferably, the method further comprises a step of heating the longitudinal junction zone.

[0060] Further features and advantages of the present invention will become more apparent from the following indicative and thus non-limiting description of an embodiment of a machine and a method for producing a continuous rod for the tobacco industry according to the invention.

[0061] Brief description of drawings

[0062] Such a description will be given below with reference to the accompanying drawings, merely provided for indicative and thus non-limiting purposes, in which: figure 1 shows a diagrammatic view of a first embodiment of a machine of the present invention; figure 2 shows a section view of a part of the machine in figure 1 ; figure 3 shows a diagrammatic view of a second embodiment of a machine of the present invention; figure 4 shows a section view of a part of the machine in figure 3; figure 5 shows a section view of a rod obtained with the machine of the present invention.

[0063] With reference to the accompanying figures, “M” indicates a machine for manufacturing a continuous rod “T” for the tobacco industry.

[0064] Detailed description of preferred embodiments of the invention

[0065] In accordance with a particular embodiment, the machine "M" is a machine for manufacturing a continuous rod "T" for a filter.

[0066] In other words, the continuous rod produced by the machine "M" is intended to form segments having a filtering function.

[0067] In particular, the continuous rod “T” has a filling material “R” made of a filtering material and an outer coating made by winding a continuous web “N” about the filling material “R”.

[0068] Alternatively, the machine “M” can produce a continuous rod intended to form segments having a cooling function and / or a spacing function and / or a retaining function and / or an aerosol generating function. For example, according to an alternative embodiment, the machine “M” is a machine for manufacturing a continuous rod “T” of aerosol generating material. In such an embodiment, in particular, the continuous rod “T” has a filling material “R” made of an aerosol generating material and an outer coating made by winding a continuous web “N” about the filling material “R”. In the preferred embodiment, the continuous web “N” is made of a biodegradable material. In particular, according to a preferred embodiment, the continuous web “N” is made of a paper or cellulose-based material. However, the material used can be different without altering the inventive concept of the present invention.

[0069] According to an aspect of the present invention, the continuous web “N” can preferably be made of a paper material, having a higher or lower weight. In particular, by way of example, said continuous web “N” can have a weight between 1 and 200 grams per square meter. More in particular, said continuous web “N” can have a weight between 1 and 100 grams per square meter.

[0070] In the preferred embodiment, the filling material “R” is a continuous web. In particular, the filling material “R” of the continuous rod “T” is a continuous web gathered in a tubular shape.

[0071] Preferably, the continuous web forming the filling material “R” is made of a biodegradable material. In particular, according to a preferred embodiment, the web intended to define the filling material “R” is made of a cellulose- based material (such as paper, cellulose acetate, viscose, lyocell, crosslinked nanocellulose) or PLA or non-woven fabric or tobacco or a combination thereof. Alternatively, the filling material “R” could not be in the form of a web.

[0072] In accordance with possible embodiments, it could be in the shape of a continuous web comprising a tobacco-based material or a nicotine- containing substrate or an aerosol generator.

[0073] As further examples, the filling material “R” can comprise (or be obtained from) fibers of plant origin, such as cotton, hemp, jute, linen, colza, bamboo, coconut fiber, kenaf, raffia, ramie, for example.

[0074] Alternatively, the filling material “R” of the continuous rod “T” is made from a bulk material or from a yarn material suitably processed to form the filling.

[0075] The machine “C” comprises first feeding means 100 for feeding a continuous web “N”, configured to feed a continuous web “N” along a first advancement path.

[0076] Such a continuous web “N” has a longitudinal extension and ideally has the following three longitudinal extension bands: a first side band “N1”; a second side band “N2” opposite to the first side band “N1”; a central band positioned between the first side band “N1” and the second side band “N2”. Such a continuous web “N” has a first surface and a second surface opposing the first surface.

[0077] The continuous web “N” is preferably unwound from a coil and the first feeding means 100 comprise a support for the coil from which the continuous web “N” is progressively unwound and appropriate guide rollers positioned along the first advancement path. Alternatively, the continuous web “N” could be folded in a zig-zag shape forming a stack and be unwound therefrom.

[0078] The machine “M” further comprises second feeding means 200 for feeding a filling material “R”, configured to feed the filling material “R” along a second advancement path.

[0079] According to an embodiment, the second feeding means 200 comprise a container in which a bale is positioned, from which the filling material “R” is progressively extracted, and appropriate guide rollers positioned along the second advancement path for guiding the material.

[0080] Alternatively, according to a preferred embodiment, the filling material “R” is unwound from a coil, and the second feeding means 200 comprise a support for such a coil from which the continuous web of filling material “R” is progressively unwound, and appropriate guide rollers arranged along the second advancement path.

[0081] Alternatively, the continuous web of filling material “R” could be folded in a zigzag shape forming a stack and be unwound therefrom.

[0082] Preferably, the machine “M” comprises processing means for the filling material “R” arranged at the second advancement path, in particular arranged between the second feeding means 200 and a joining zone “U” in which the first and second advancement paths converge.

[0083] If the filling material “R” is in the form of a continuous web, the processing means can comprise at least a pair of rollers intended to define a plurality of deformation and / or cutting lines along the continuous web.

[0084] In particular, the rollers are arranged so that the continuous web of the filling material “R” passes therebetween and are shaped so as to create a deformation and / or cutting pattern on the web, which facilitates the subsequent gathering of the web in a tubular shape. For example, the deformation and / or cutting pattern can comprise a plurality of longitudinal lines for deforming and / or cutting the continuous web.

[0085] The machine “M” further comprises, in particular downstream of the joining zone “U”, a winding station 300 configured to perform a progressive winding of the continuous web “N” in a tubular shape about the filling material “R”, thus obtaining a continuous rod “T” with filling provided with a longitudinal joining zone, preferably at the top or substantially at the top. In other words, the longitudinal junction zone is defined by overlapping and securing the first side band “N1” and the second side band “N2” together (Figure 5).

[0086] Preferably, the winding station 300 has a forming section 300a configured to deform the continuous web “N” in a curved shape about a longitudinal axis but defining a still open shape.

[0087] After the forming section 300a, the winding station 300 also has a closing section 300b configured to close the continuous web “N” in a tubular shape by abutting or overlapping the opposing edges (i.e., of the first side band “N1” and the second side band “N2”) of the continuous web “N”, to define the mentioned longitudinal junction zone.

[0088] In other words, in the forming section 300a, the continuous web “N” starts to be progressively wound about the filling material “M” until the opposing edges (i.e., the first side band “N1” and the second side band “N2”) of the continuous web “N” overlap in the closing section 300b, so as to define the rod “T”.

[0089] In the preferred embodiment, the opposing edges of the continuous web “N” mutually overlap and define a rod “T” having an overlapping zone.

[0090] In a preferred embodiment, the continuous web “N” is in the form of a multilayer web with layers having laterally offset end edges to define an overlapping zone with abutting edges, in particular, in which the abutment lines of the different layers are angularly offset about the longitudinal axis.

[0091] The machine “M” further comprises a first gluing device 400 arranged along the first advancement path and upstream of the joining zone “U”, and configured to apply a cold adhesive at the first band “N1” of the continuous web “N”.

[0092] The first band “N1” defines the longitudinal junction zone, in particular by overlapping, of the continuous rod “T” (Figure 5).

[0093] The machine “M” further comprises a second gluing device 600 arranged downstream of the joining zone “U” and configured to apply a cold adhesive at the first band “N1” of the continuous web “N”.

[0094] In accordance with the embodiment in Figure 1 , the second gluing device 600 is arranged upstream of the winding station 300 to apply the cold adhesive to the first band “N1” of the continuous web “N”, in particular while the continuous web “N” lies flat (Figure 2).

[0095] In accordance with the embodiment in Figure 3, instead, the second gluing device 600 is arranged in the forming section 300a of the winding station 300 to apply the cold adhesive to the first band “N1” of the continuous web “N”, in particular while the first band “N1” is inclined with respect to the rest of the continuous web “N” (Figure 4).

[0096] Preferably, the first and second gluing devices 400, 600 apply the same type of cold adhesive to the continuous web “N”.

[0097] Preferably, the cold adhesive applied by the first and second gluing devices 400, 600 is a glue. Preferably, such a cold adhesive is an adhesive paste (more or less thick), such as a water-based adhesive, for example, such as a starch glue or PVA or EVA.

[0098] Preferably, the first gluing device 400 and the second gluing device 600 are the same.

[0099] In accordance with a possible embodiment, the first gluing device 400 and the second gluing device 600 each comprise a dispensing nozzle to apply the cold adhesive to the continuous web "N".

[0100] Alternatively, the first gluing device 400 and the second gluing device 600 could each comprise a spreader or a roller or a spray nozzle for the application of the cold adhesive to the continuous web "N".

[0101] Preferably, the first gluing device 400 and the second gluing device 600 are each configured to apply at least one line of adhesive at the first band "N1" of the continuous web "N".

[0102] Preferably, the first and the second gluing devices 400, 600 are configured to apply the same number of lines of adhesive.

[0103] The term “line of adhesive” is understood to mean the application of an adhesive along a longitudinal, preferably continuous, or substantially continuous, or discontinuous line or web. Such a line of adhesive can be formed by a strip of adhesive or, for example, by a set of adhesive dots applied one after the other.

[0104] The line of adhesive can be a straight line, i.e., substantially parallel to the edge of the continuous web “N”, or can have a non-rectilinear development (e.g., wavy or zigzag-shaped).

[0105] In accordance with a particular embodiment, the first and second gluing devices 400, 600 each comprise two or more dispensing nozzles to apply two or more longitudinal lines of adhesive to the continuous web "N". Alternatively, the first gluing device 400 and the second gluing device 600 could each comprise two or more spreaders or rollers or spray nozzles for applying the adhesive to the continuous web "N".

[0106] The longitudinal lines of adhesive are preferably mutually parallel. All the aforesaid longitudinal lines of adhesive are preferably positioned so as to be included in the longitudinal junction zone in the continuous rod “T”.

[0107] In other words, all the lines of adhesive (applied by the first gluing device 400 or the second gluing device 600) are applied to the continuous web "N" so that once wound and in a configuration with overlapping edges, the longitudinal lines of adhesive are all interposed between the first band "N1" of the continuous web "N" and the second band "N2" of the continuous web "N" opposing the first band "N1".

[0108] It is understood that, in accordance with a non-preferred embodiment, the first gluing device 400 and the second gluing device 600 can be of a different type and / or be configured to apply a different number of lines of adhesive to the continuous web "N":

[0109] As shown in the accompanying Figures, the machine "M" further comprises a heating device 500, in particular arranged downstream of the winding station 300, configured to operate a heating (drying) of the cold adhesive released by the first or second gluing device 400, 600.

[0110] In other words, once the first band "N1" and the second band "N2" overlap each other, the heating device 500 raises the temperature in the longitudinal junction zone so as to heat the cold adhesive placed there and dry the adhesive to promote the closure of the continuous rod "T".

[0111] According to an embodiment, the conformation of the heating device 500 has at least one plate (possibly counter-shaped with respect to the continuous rod “T”), positioned facing (preferably in contact with) the continuous rod “T” in the longitudinal junction zone.

[0112] In particular, the heating device 500 has a longitudinal extension (substantially parallel to the rod “T”).

[0113] In other words, the heating device 500 has a predefined length at which it is positioned in contact (or substantially in contact) with the junction zone of the rod “T” to heat (and thus dry) the adhesive. It is understood that, after establishing the energy supplied by the heating device 500 and the advancement speed of the rod “T”, the greater the length of the heating device 500, the greater the drying effect of the adhesive.

[0114] In the preferred embodiment, the machine “M” further comprises a pressing member arranged at the winding station 300 or downstream of the winding station 300 and configured to keep the first band “N1” and the second band “N2” of the continuous web “N” mutually overlapping, so as to promote the closing of the continuous rod “T”.

[0115] The heating device 500 is preferably integrated in the pressing member.

[0116] Alternatively, the heating device 500 and the pressing member are two discrete and consecutive elements, so that the pressing member is at least partially downstream of the heating device 500.

[0117] According to an aspect of the invention, the machine “M” further comprises a control unit “C” connected to the first and second gluing devices 400, 600 and configured to selectively activate the first and second gluing devices 400, 600 based on a speed parameter of the machine “M”, in particular the advancement speed of the continuous web “N” along the first advancement path.

[0118] It is emphasized that the speed parameter of the machine “M” is reflected in the linear speed of all components, i.e., the continuous web “N” and the filling material “R”, which define the continuous rod “T”.

[0119] Based on the speed parameter of the machine “M”, and in particular based on the advancement speed of the continuous web “N”, the control unit “C” activates one of the first and second gluing devices 400, 600 so as to apply the cold adhesive to the web “N” along the first advancement path or downstream of the joining zone “U”.

[0120] Selectively controlling the activation of the first and second gluing devices 400, 600 based on the advancement speed of the continuous web “N” allows the cold adhesive to begin a pre-drying process along the path from the gluing device 400, 600 activated by the control unit “C” to the winding station 300 (and in particular to the heating device 500, where the actual drying occurs).

[0121] In fact, in order to dry the cold adhesive, a certain time and / or a certain amount of energy is required.

[0122] Such an energy cannot be supplied too quickly since it could risk damaging or degrading the continuous web “N” and / or the filling material “R”. For example, increasing the energy supplied by the heating device 500 could deteriorate the continuous web “N”. In such a situation, based on the advancement speed of the continuous web “N”, by applying the adhesive in an appropriate point in the advancement path of the continuous web “N”, it is possible to perform a sort of pre-drying of the adhesive before it reaches the heating device 500. Therefore, given the same amount of energy supplied by the heating device 500, controlling the point of application of the adhesive to the continuous web “N”, based on the advancement speed thereof, advantageously allows reducing the time in which the energy of the heating device 500 must act on the continuous rod “T”.

[0123] Preferably, the control unit “C” is configured to activate the first gluing device 400 if the speed parameter is above a threshold value between 100 m / min and 350 m / min, preferably between 150 m / min and 300 m / min, and even more preferably between 200 m / min and 250 m / min.

[0124] In such a situation, since in current machines the continuous web “N” is advanced at a particularly high speed, it is advantageous to apply the adhesive to the continuous web “N” at a point, along the first advancement path, as far upstream as possible with respect to the zone where the continuous rod “T” is obtained (i.e. , as far upstream as possible with respect to the heating device 500). Since the first gluing device 400 is more distant from the zone where the continuous rod “T” is obtained than the second gluing device 600, the control unit “C” activates such a gluing device 400 when the advancement speed of the continuous web “N” is high.

[0125] Preferably, the control unit “C” is configured to activate instead the second gluing device 600 if the speed parameter is below the aforesaid threshold value.

[0126] Therefore, in such a situation, the control unit “C” activates the second gluing device 600, i.e., that arranged closer to the zone where the continuous rod “T” is obtained (i.e., closer to the heating device 500). By doing so, although the application of the adhesive occurs at a point in the advancement path which is closer to the zone where the continuous rod “T” is obtained, there is sufficient time for the cold adhesive to dry by virtue of a lower advancement speed of the continuous web “N” (in other words, not too much heat emitted by the heating device 500 is necessary as it has more time to dry said cold adhesive).

[0127] In accordance with an embodiment, the control unit “C” is configured to receive the speed parameter of the machine “M”. In detail, the control unit “C” is configured to receive the speed parameter of the machine “M” by means of an input interface, e.g., by means of a screen, a smartphone, and the like.

[0128] Alternatively, the control unit “C” is configured to detect the speed parameter of the machine “M” by means of at least one sensor applied to the machine, preferably an angular encoder.

[0129] Alternatively, the control unit “C” is configured to load the speed parameter of the machine “M” from a database for setting the machine “M” or from a current configuration set for the machine “M”.

[0130] According to a possible embodiment of the invention, the control unit “C” is configured to selectively activate the first and second gluing devices 400, 600 also based on at least one additional parameter.

[0131] Preferably, the additional parameter is selectable from:

[0132] - a physical property of the cold adhesive applied by the first or second gluing device 400, 600, e.g., viscosity, granularity, chemical composition, and the like;

[0133] - a physical property of the continuous web “N”, e.g., thickness, weight, and the like.

[0134] In use, once the control unit “C” has established the value of the speed parameter of the machine “M”, one of the first and the second gluing devices 400, 600 is activated to apply the cold adhesive to the continuous web “N”. If the continuous web “N” is advancing at a particularly high speed, the first gluing device 400, i.e., that being spaced apart from the heating device 500, is activated. In such a situation, the cold adhesive is applied to the continuous web “N” during the advancement thereof along the first advancement path. The continuous web “N”, provided with the cold adhesive, then encounters the filling material “R” in the joining zone “U” and then enters the winding station 300 where the continuous web “N” is wound about the filling material “R”.

[0135] Conversely, if the continuous web “N” is advancing at a lower speed, the second gluing device 600, i.e., that being closer to the heating device 500, is activated. In such a situation, the cold adhesive is applied to the continuous web “N” downstream of the joining zone “U”, and in particular:

[0136] - just before the continuous web “N” (and the filling material “R”) enters the forming station 300; or

[0137] - while the continuous web “N” (and the filling material “R”) is in the forming station 300, and in particular in the forming section 300a.

[0138] At the outlet of the winding station 300, the overlapping zone of the continuous web “N” is heated by the heating device 500 so as to dry the adhesive.

[0139] In order to further reduce the time required for drying the cold adhesive once the continuous rod “T” has been formed (and also the energy consumed by the heating device 500), preferably (but not mandatorily) the machine “M” can comprise at least one pre-heating device 700, 800.

[0140] In particular, the at least one pre-heating device 700, 800 is arranged upstream or at the winding station 300 (and in particular upstream of the heating device 500) and is configured to operate a pre-heating of the at least one adhesive released by one of the first or second gluing device 400, 600. In addition or alternatively to the pre-heating of the adhesive, the at least one pre-heating device 700, 800 is configured to operate a pre-heating of the continuous web N, in particular at least the first band N1 of said continuous web N intended to receive said adhesive. According to an aspect of the invention, the at least one pre-heating device 700, 800 comprises at least one electrical resistor to operate a pre-heating, preferably an increase in temperature, of the released adhesive and / or the first band N1 of the continuous web N.

[0141] In addition or alternatively, the at least one pre-heating device 700, 800 comprises an induction system to operate a pre-heating, preferably an increase in temperature, of the released adhesive and / or the first band N1 of the continuous web N.

[0142] Further in addition or alternatively, the at least one pre-heating device 700, 800 comprises an infrared system or a radiofrequency system or a microwave system to operate a pre-heating, preferably an increase in temperature, of the adhesive and / or the first band N1 of the continuous web N.

[0143] In addition or alternatively, the at least one pre-heating device 700, 800 comprises a laser emitter configured to operate a pre-heating, preferably an increase in temperature, of the released adhesive and / or of the first band N1 of the continuous web N.

[0144] In accordance with the preferred embodiment, the machine "M" comprises a first pre-heating device 700 arranged upstream of the joining zone "U", in particular arranged in a position between the first gluing device 400 and the joining zone "U", configured to operate a pre-heating of the adhesive released by the first gluing device 400 (Figures 1 and 3).

[0145] In addition or alternatively to the first pre-heating device 700, the machine "M" can comprise a second pre-heating device 800 arranged downstream of the joining zone "U" (Figures 1 and 3), in particular positioned in a position between the joining zone "U" and the winding station 300 (Figure 1 ), configured to operate a pre-heating of the adhesive released by the first or second gluing device 400, 600. Alternatively, the second pre-heating device 800 can be arranged at the winding station 300 (Figure 3).

[0146] According to an embodiment, each pre-heating device 700, 800 is configured to operate a pre-heating of the adhesive released by the respective gluing device 400, 600. In accordance with a further embodiment, the second pre-heating device 700, 800 can be configured to operate a pre-heating of the adhesive released by one of the gluing devices 400, 600. In addition or alternatively, each pre-heating device 700, 800 can be configured to operate a pre-heating of the first band N1 of the continuous web N intended to receive the adhesive.

[0147] In other words, each pre-heating device 700, 800 is thus configured to increase the temperature of the at least one adhesive and / or the web N so as to partially dry such an adhesive before it is interposed between the first band N1 and the second band N2 in the junction zone (in particular, before it is subjected to the actual heating performed by the heating device 500). Therefore, in such a situation, with the energy supplied by the heating device 500 being the same, it is possible to reduce the time needed by the heating device 500 to completely dry the adhesive.

[0148] Preferably, the control unit "C" is configured to selectively activate the first gluing device 400 and the first pre-heating device 700 or the second gluing device 600 and the second pre-heating device 800 or the first gluing device 400 and the second pre-heating device 800.

[0149] In other words, at least based on the speed parameter, if the first gluing device 400 is activated, the first pre-heating device 700 or the second preheating device 800 is also activated. If the second gluing device 600 is activated, the second pre-heating device 800 is also activated.

[0150] Therefore, among the possible embodiments of the machine "M," only the first pre-heating device 700 (which pre-heats the cold adhesive applied by the first gluing device 400) or only the second pre-heating device 800 (which pre-heats the cold adhesive applied by either the first gluing device 400 or the second gluing device 600), or both pre-heating devices 700, 800 can be provided.

[0151] Preferably, the control unit "C" is configured to vary the amount of energy emitted by the first pre-heating device 700 and / or the second pre-heating device 800 between a minimum value and a maximum value based on a value of the operating parameter.

[0152] In other words, the control unit "C" is configured to modulate the amount of energy supplied by the pre-heating devices 700, 800 (whether there is only one or both).

[0153] The present invention also relates to a method for manufacturing a continuous rod “T” for the tobacco industry.

[0154] The method comprises a step of advancing a continuous web “N” along a first feed path.

[0155] By way of non-limiting example, such a continuous web “N” can be advanced being fed from a coil and guided by guide rollers. Alternatively, the continuous web “N” can be unwound from a stack formed by overlapping layers of continuous web, folded in a zig-zag shape.

[0156] The method further comprises a step of advancing a filling material “R” along a second advancement path converging with the first advancement path in a joining zone “U”.

[0157] The method further comprises a step of applying at least one cold adhesive to the continuous web “N” at a first band (in particular, a side band) “N1” of the continuous web “N”.

[0158] Preferably, the adhesive is a water-based adhesive (e.g., PVA or EVA) or is an adhesive paste (e.g., starch glues).

[0159] Preferably, the step of applying the cold adhesive to the continuous web “N” includes applying at least one longitudinal line of adhesive.

[0160] The aforesaid longitudinal lines of adhesive are positioned so as to be included in a longitudinal junction zone of the continuous rod “T”. Longitudinal junction zone of the continuous rod “T” means the zone of the continuous rod “T” in which the first band (side band) “N1” of the web “N” and a second band (side band) “N2” of the web “N” mutually overlap.

[0161] The step of applying the cold adhesive to the continuous web “N” is operable by means of a first gluing device 400, arranged along the first advancement path upstream of the joining zone “U”, or by means of a second gluing device 600, arranged downstream of the joining zone “U”. Both gluing devices 400, 600 are simultaneously present.

[0162] The step of applying the at least one cold adhesive comprises a sub-step of selectively activating one of the gluing devices 400, 600 based on a speed parameter of the machine, in particular, the advancement speed of the continuous web “N”.

[0163] In such a situation, only one of the two gluing devices 400, 600 is activated to dispense the cold adhesive onto the continuous web “N”.

[0164] After the step of applying, the method comprises a step of winding the continuous web “N” about the filling material “R” thus obtaining a continuous rod “T”.

[0165] Preferably, the step of winding is carried out so that the first side band “N1” is in contact with an opposing second side band “N2” of the continuous web “N”, thus obtaining the continuous rod “T” defined by a tubular coating containing the filling material “R” and having the longitudinal junction zone with the adhesive.

[0166] The first lateral band “N1” preferably overlaps the second lateral band “N2”. The step of winding the continuous web “N” about the filling material “R” comprises a sub-step of deforming the continuous web “N” into a curved shape about a longitudinal axis.

[0167] Preferably, in the deforming step, the continuous web “N” takes, in section, a substantially “U” shape.

[0168] The step of winding further comprises an additional sub-step of securing, e.g., by abutting or overlapping, the opposing edges of the continuous web “N”, thus defining a longitudinal junction zone of the continuous rod “T”. Once the longitudinal junction zone is obtained, it can be heated.

[0169] In other words, the temperature in the longitudinal junction zone is increased so that the adhesive dries and keeps the opposing edges in the continuous web “N” joined to form the rod “T”.

[0170] The present invention achieves the preset objects, eliminating the drawbacks of the prior art. In detail, the possibility of selectively activating the gluing devices 400, 600 allows using an adhesive of the cold type without needing to reduce the production speed of the machine due to the drying times of such an adhesive. The possibility of selectively activating the gluing devices 400, 600 thus allows maintaining the production speed of the machine “M” and producing a continuous rod “T” with biodegradable materials. In fact, by employing a web “N” and a filling material “R” made of biodegradable materials, the use of a cold adhesive allows producing a continuous tubular piece for the creation of entirely biodegradable segments. Furthermore, the continuous tubular piece for producing segments has an external tubular piece having durable shape and structure over time, which avoids unwanted or unexpected detachments of the side edges of the continuous web.

Claims

CLAIMS1 . A machine (M) for manufacturing a continuous rod (T) for the tobacco industry, comprising:- first feeding means (100) for feeding a continuous web (N) and configured to advance a continuous web (N) along a first advancement path;- second feeding means (200) for feeding a filling material (R), configured to advance the filling material (R) along a second advancement path, said first and second advancement paths converging toward a joining zone;- a winding station (300) configured to progressively wind the continuous web (N) in a tubular shape about said filling material (R) thus obtaining a continuous rod (T);- a first gluing device (400), arranged along the first advancement path and upstream of the joining zone (U) and configured to apply a cold adhesive at a first band (N1 ), in particular a side band, of said continuous web (N), said first band (N1 ) defining a longitudinal junction zone, in particular by overlapping, in said continuous rod (T);- a second gluing device (600) arranged downstream of the joining zone (U) and configured to apply a cold adhesive at said first band (N1 );- a control unit (C) connected to the first and second gluing devices (400, 600) and configured to selectively activate said first and second gluing devices (400, 600) based on a speed parameter of the machine (M), in particular the advancement speed of the continuous web (N) along said first advancement path.

2. A machine according to claim 1 , wherein the control unit (C) is configured to selectively activate said first and second gluing devices (400, 600) also based on at least one additional parameter, preferably said additional parameter being selectable from:- a physical property of the cold adhesive applied by said first or second gluing device (400, 600);- a physical property of the continuous web (N).

3. A machine according to claim 1 or 2, wherein said control unit (C) is configured to activate said first gluing device (400) if the speed parameter is above a threshold value and to activate said second gluing device (600) if the speed parameter is below said threshold value; preferably said threshold value being between 100 m / min and 350 m / min, more preferably between 150 m / min and 300 m / min, and even more preferably between 200 m / min and 250 m / min.

4. A machine according to any one of the preceding claims, wherein said first and second gluing devices (400, 600) are configured to apply at least one line of adhesive at the first band (N1 ) of said continuous web (N), preferably said first and second gluing devices (400, 600) being configured to apply the same number of lines of adhesive.

5. A machine according to any one of the preceding claims, comprising a heating device (500), arranged downstream of the winding station (300), configured to operate a heating of said adhesive released by one of the first gluing device (400) and the second gluing device (600).

6. A machine according to any one of the preceding claims, comprising at least one pre-heating device (700, 800) arranged upstream or at the winding station (300) and configured to pre-heat the at least one adhesive released by one of the first gluing device (400) and the second gluing device (600) and / or the first band (N1 ) of said continuous web (N) intended to receive said adhesive.

7. A machine according to claim 6, comprising: a first pre-heating device (700) arranged upstream of the joining zone (U), in particular arranged in a position between the first gluing device (400) and the joining zone (U), configured to pre-heat the adhesive released by the first gluing device (400); and / or a second pre-heating device (800) arranged downstream ofthe joining zone (U), in particular arranged in a position between the joining zone (U) and the winding station (300), configured to pre-heat the adhesive released by the first gluing device (400) or by the second gluing device (600).

8. A machine according to claim 7, wherein said control unit (C) is configured to selectively activate said first gluing device (400) and said first pre-heating device (700) or said second gluing device (600) and said second pre-heating device (800) or said first gluing device (400) and said second pre-heating device (800).

9. A machine according to claim 7 or 8, wherein said control unit (C) is configured to vary the amount of energy emitted by the first pre-heating device (700) and / or the second pre-heating device (800) between a minimum value and a maximum value, in particular based on a value of said operating parameter.

10. A machine according to any one of the preceding claims, wherein said winding station (300) has a forming section (300a) configured to deform the continuous web (N) into a curved shape about a longitudinal axis and a subsequent closing section (300b) configured to close the continuous web (N) in a tubular shape by securing the opposing edges of the continuous web (N).1 1. A machine according to claim 10, wherein the second gluing device (600) is arranged in said forming section (300a) of the winding station (300) to apply said at least one adhesive to the first band (N1 ) of the continuous web (N), in particular while said first side band (N1 ) has an inclined orientation with respect to the rest of the continuous web (N) or the second gluing device (600) is arranged upstream of the winding station (300) to apply said at least one adhesive onto the first band (N1 ) of the continuousweb (N), in particular while the continuous web (N) has a planar arrangement.

12. A machine according to any one of the preceding claims, wherein the filling material (R) is a continuous web preferably comprising a cellulose- based material or PLA or non-woven fabric or tobacco or a combination thereof.

13. A machine according to any one of the preceding claims, wherein said control unit (C) is configured to receive said speed parameter of the machine (M), in particular by means of an input interface, or to detect said speed parameter of the machine (M) by means of at least one sensor applied to the machine, preferably an angular encoder.

14. A machine according to any one of the preceding claims 1 to 12, wherein said control unit (C) is configured to load said speed parameter of the machine (M) from a database for setting the machine (M) or from a current configuration set for the machine (M).

15. A method for manufacturing a continuous rod (T) for the tobacco industry, preferably operated by a machine according to one or more of the preceding claims, comprising the following steps:- advancing a continuous web (N) along a first advancement path;- advancing a filling material (R) along a second advancement path converging with the first advancement path in a joining zone (U);- progressively wrapping the continuous tape (N) in a tubular shape about said filling material (R) thus obtaining a continuous rod (T);- applying at least one cold adhesive to said continuous web (N) at a first side band (N1 ) of said continuous web (N), said first band (N1 ) defining a longitudinal junction zone, in particular by overlapping, in said continuous rod (T);wherein said step of applying the at least one cold adhesive at the first band (N1 ) of said continuous web (N) is operable by means of a first gluing device (400), arranged along said first advancement path upstream of the joining zone (U), or a second gluing device (600), arranged downstream of the joining zone (U), both said gluing devices (400, 600) being simultaneously present; and wherein said step of applying the at least one cold adhesive comprises a sub-step of selectively activating one of said gluing devices (400, 600) according to a speed parameter of the machine, in particular the advancement speed of the continuous web (N).

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