Machine and method in the tobacco-processing industry for producing a rod or paper filter, and use of the machine

Abstract

The invention relates to: a machine (2) in the tobacco-processing indusutry; a method for producing a paper filter; and the use of the machine (2). The machine (2) comprises, arranged one after the other in a material flow direction: a flat web providing device (8), a flat web structuring device (12), a flat web preforming device (26), and a rod forming device (28). A transport roller (24) is located between the flat web structuring device (12) and the flat web preforming device (26), and an application device (18) is located between the flat web structuring device (12) and the flat web preforming device (26), said application device (18) being designed to apply an additive (22) to at least one upper side (20) of the flat web (4), the application device (18) comprising a wide-slot nozzle (94) for applying the additive (22).

Description

[0001] Machine and method of the tobacco processing industry for producing a rod or paper filter and use of the machine

[0002] Description

[0003] The invention relates to a machine in the tobacco processing industry for producing a strand from a flat web, comprising the following devices arranged one behind the other in a material flow direction: a flat web supply device for supplying the flat web, a flat web structuring device, in particular a crimping device, with which a structure can be introduced into the flat web, giving the flat web a cross-section that is modified at least in sections when spread out, a flat web preforming device with which the flat web can be converted into a preformed state, and a strand forming device with which the strand can be produced from the preformed flat web. The invention also relates to the use of such a machine.

[0004] Furthermore, the invention relates to a method for producing paper filters using a machine in the tobacco processing industry for producing a strand from a flat web, wherein the machine comprises the following devices arranged one behind the other in a material flow direction: a flat web supply device which provides the flat web, a flat web structuring device, in particular a crimping device, with which a structure is introduced into the flat web, by means of which the flat web, in the spread-out state, receives a cross-section which is changed at least in sections, a flat web pre-forming device with which the flat web is converted into a pre-formed state, and a strand forming device with which the strand is produced from the pre-formed flat web.

[0005] Flat sheets are used for various purposes in the tobacco processing industry and are often processed into an infinitely long strand in a continuous process. Such a strand can be used to produce rod-shaped articles for the tobacco processing industry, such as filters or filter segments. Other application examples in which a rod-shaped article for the tobacco processing industry is produced from a strand are articles made from a flat sheet of reconstituted tobacco material (RECON) or from PLA film. Such rod-shaped segments can be used in so-called HNB articles (for "Heat-Not-Burn"), which are also known as THP articles (for "Tobacco-Heated-Product"). Such a product from the tobacco processing industry is heated and not burned, so that as a result of the heating, the ingredients of the tobacco material are released and made available for consumption in an air stream.

[0006] If a paper web is used as a flat sheet, it can be used to produce paper filters or paper filter segments, for example. Compared to conventional filter segments, these are advantageously biodegradable.

[0007] A key process step in the processing of a flat web into, for example, one of the rod-shaped articles mentioned above, is the forming of the flat web from a flat, spread-out state into a folded or gathered intermediate state and then into a strand with a substantially round cross-section. For this purpose, the flat web is gathered transversely to its longitudinal direction using a forming unit, for example, and then formed into a strand in a formatting unit, which can then be wrapped.

[0008] In some cases, it is desirable to add an additive to the filter material, such as a flavoring. Such an additive is often applied to the flat sheet in its flat, spread-out state. However, it can also be applied to the sheet gathered in a direction transverse to its longitudinal direction.

[0009] WO 2022 / 090268 A1 discloses partially fanning out the gathered flat web in order to apply the additive to the flat web in this state. The device known from this document uses a plurality of individual nozzles. These are arranged in recesses of an application device, so that the additive is applied locally to the flat web in a spraying process.

[0010] A device for applying an additive to conventional filter material made of fibers is known, for example, from EP 0 913 100 A2. In the device known from this document, a powdered material with a very small particle size is pneumatically sprayed onto the fiber material using a solids injector nozzle.

[0011] It is an object of the invention to provide a machine for the tobacco processing industry for producing a strand from a flat web, the use of such a machine and a method for producing paper filters from a flat web, wherein the application of an additive to the flat web is to be improved.

[0012] The object is achieved by a machine in the tobacco processing industry for producing a strand from a flat web, comprising the following devices arranged one behind the other in a material flow direction: a flat web supply device for providing the flat web, a flat web structuring device, in particular a crimping device, with which a structure can be introduced into the flat web, by means of which the flat web, in the spread-out state, receives a cross-section which is changed at least in sections, a flat web pre-forming device with which the flat web can be converted into a pre-formed state, and a strand forming device with which the strand can be produced from the pre-formed flat web, this machine being further developed in thatthat a transport roller is arranged between the flat web structuring device and the flat web preforming device, and the flat web is guided in the material flow direction by means of and / or along the transport roller, and the transport roller is arranged and designed to guide the spread-out flat web and / or to adjust a web tension of the flat web on a transport path between the flat web structuring device and the flat web preforming device, and between the flat web structuring device of the flat web preforming device, in particular between the flat web structuring device and the transport roller, an application device is arranged which is arranged to apply an additive, in particular a liquid, to at least one upper side of the flat web, which is opposite a lower side with which the flat web contacts the transport roller,wherein the application device comprises a slot die for applying the additive.

[0013] Advantageously, the wide slot die included in the application device allows the additive to be applied quickly and efficiently and, if desired, across the entire width of the flat web, i.e. not just locally, for example along application tracks. This makes it possible to apply a sufficiently large amount of additive homogeneously to the flat web, even at high process speeds. The wide slot die comprises, in particular, a die gap through which the additive emerges. A longitudinal direction of the die gap is oriented at least approximately perpendicular to a transport direction of the flat web. Furthermore, in particular, the wide slot die has a die gap which has a longitudinal direction which corresponds at least approximately to the width of the flat web.If the length of the nozzle gap, viewed in its longitudinal direction, is selected to be slightly shorter than the width of the flat web, this can prevent the additive from bypassing the flat web, for example, into a collection area provided for this purpose. There is no so-called "overspray", which inevitably results in material being lost. At the very least, the overspray is significantly reduced. If the length of the nozzle gap is selected to be the same as or even slightly larger than the width of the flat web, a certain amount of overspray is accepted. In return, the flat web can be wetted with the additive right across the edge. By wetting the flat web right across the edge, a particularly large amount of additive can be applied to the flat web.

[0014] A slot die also allows for the flexible application of various materials that can be used as additives. The additive material ranges from liquids to highly viscous materials that may be solid at room temperature. These can be liquids, solids, or mixtures of substances, such as dispersions, suspensions, gels, or the like.

[0015] The machine in the tobacco processing industry also includes a transport roller designed to guide the flat web and / or maintain, control, and / or regulate the web tension of the flat web. This measure can advantageously improve the application of the additive using the slot die. If the position and web tension of the flat web are kept within specified limits, this improves the application of the additive using the slot die. The two aforementioned measures—the effect of the transport roller on the one hand and the function of the slot die with regard to the application of the additive on the other—thus interact in a synergistic manner.

[0016] To assist in the application of the additive to the flat web, one embodiment provides for the application device to comprise a compressed-air-assisted slot die. With the aid of compressed air, the slot die ensures a homogeneous application of the additive by uniformly distributing it transversely to the longitudinal direction of the flat web. Furthermore, the use of compressed air allows the application of the additive to be controlled and / or regulated even more precisely. For example, the application quantity and application speed can be adapted to the type of material of the flat web, such as its porosity or air permeability. Adapting the application of the additive enables the tobacco processing industry to achieve high process speeds with the machine.

[0017] According to an advantageous embodiment, it is further provided that the slot die comprises a die gap provided for the additive and at least one air gap running at least approximately parallel to the die gap on one side thereof, in particular a pair of air gaps running at least approximately parallel to the die gap on both sides thereof.

[0018] Preferably, the at least one air gap is aligned parallel to the nozzle gap of the slot die. This applies both to a pair of air gaps arranged on either side of the nozzle gap and to a single air gap arranged on one side of the nozzle gap.

[0019] The air gap has a length, viewed in its longitudinal direction, which is less than or equal to the length of the nozzle gap, viewed in the same direction. According to a further embodiment, the air gap also has a length that is greater than the length of the nozzle gap. In this way, the additive emerging from the nozzle gap can be completely enclosed in a sheath air flow, provided two air gaps are provided on either side of the nozzle gap, so that overspray can be further reduced.

[0020] According to a further embodiment, the machine of the tobacco processing industry is further developed in that the slot die comprises a base body provided with a heater, wherein in particular the base body comprises a storage chamber for the additive which communicates fluidically with the die gap.

[0021] A heatable slot die allows you to adjust the additive's viscosity range to ensure optimal application to the flat web. The heatability of the slot die thus makes it possible to influence this process parameter. This is particularly advantageous when the viscosity cannot be adjusted by adding suitable additives to the additive.

[0022] A heated slot die makes it possible to apply even very high-viscosity additives that could not be conveyed and applied without heating. In particular, it is provided that the additive is fed to the machine in the tobacco processing industry in a preheated state. According to a further embodiment, such an additive heating device is designed as part of the machine in the tobacco processing industry. The additive is taken, for example, from a storage container, fed to the additive heating device, and heated to the desired temperature. The heating of the slot die then ensures that the additive can be applied at the desired temperature and thus with the desired viscosity.In other words, it prevents the additive from cooling undesirably in the slot die, which could affect the additive's application, for example, because the additive has a lower viscosity at lower temperatures. A heated slot die allows the desired process window to be maintained while simultaneously optimizing the additive's application. Another positive effect is that it prevents the slot die from clogging due to cooled additive residues.

[0023] Furthermore, it is specifically intended that not only the wide-slot nozzle itself, but also the application head as a whole, is heated or can be heated by means of the provided heating system. This advantageously makes it possible to control the temperature of all media passing through the application head in the desired manner. This applies in particular to the additive, but also to the compressed air, which will be discussed in more detail below.

[0024] According to a further advantageous embodiment, the machine for the tobacco processing industry is further developed in that the nozzle gap and / or the at least one air gap is or are adjustable. The adjustability can be achieved, for example, by suitable intermediate pieces. Furthermore, it is provided in particular that a length and / or a width of the nozzle gap and / or the at least one air gap is or are adjustable. A length of the nozzle gap and a length of the air gap are measured in the direction of their respective longitudinal extent. The length of the nozzle gap or air gap often extends at least approximately parallel to a width of the flat web. A width of the nozzle gap or air gap is measured transversely to the width of the flat web, i.e. in the direction of transport of the flat web. The width of the nozzle gap orThe air gap extends transversely, in particular perpendicularly, to its respective longitudinal direction, i.e., transversely to the length of the nozzle gap or air gap. Furthermore, it is particularly provided that the width of the nozzle gap and / or the air gap is between 5 pm and 1 mm (1000 pm). Furthermore, in particular, this width is between 10 pm and 500 pm, furthermore, in particular, between 50 pm and 250 pm, furthermore, in particular, between 100 pm and 300 pm.

[0025] According to a further advantageous embodiment, the machine for the tobacco processing industry, which comprises a compressed-air-assisted slot die, is further developed in that it has a compressed-air heater configured to provide heated compressed air to the slot die. This measure is advantageous because a compressed air stream guided through the slot die inevitably cools it. This undesirable cooling effect can be prevented or at least significantly reduced by supplying heated compressed air to the slot die.

[0026] According to a further advantageous embodiment, the machine for the tobacco processing industry is further developed in that the slot die is designed as a contact slot die or as a contactless slot die. In particular, the contactless slot die is arranged such that the distance between the flat web and a nozzle gap of the slot die is between 3 mm and 60 mm.

[0027] A working distance within the specified interval has proven advantageous in practice. This working distance allows for a good compromise between low overspray on the one hand and even distribution of the additive on the other. According to further advantageous embodiments, the specified distance is between 30 mm and 50 mm, and in particular between 35 mm and 45 mm.

[0028] According to a further advantageous embodiment, the slot die is configured to process the additive with a viscosity between 50 m Pa*s and 1600 m Pa*s (m Pa*s = milli Pascal * second). In particular, the machine in the tobacco processing industry comprises a control device configured to control and / or regulate the heating system present in the base body of the slot die in such a way that the additive is tempered such that its viscosity assumes a desired value within the specified range.

[0029] In practice, it has been shown that an additive viscosity within the specified range enables good and reliable processing of the additive in the slot die. In other words, the additive can be processed in the desired manner using the slot die if its viscosity is within the specified range.

[0030] According to further advantageous embodiments, the viscosity of the additive is in a range between 100 m Pa*s and 1000 m Pa*s, and more particularly in an interval between 300 m Pa*s and 600 m Pa*s. The control unit of the machine is again configured to adjust the temperature of the slot die via the heater, so that the additive has the desired viscosity.

[0031] According to a further advantageous embodiment, an application device is arranged between the flat web structuring device of the flat web preforming device, in particular between the flat web structuring device and the transport roller, which application device is configured to apply an additive, in particular a liquid, to a top and bottom side of the flat web. In other words, the application device is designed such that the flat web can be provided with the additive on both sides.

[0032] According to a further advantageous embodiment, the machine of the tobacco processing industry is further developed in that the flat web preforming device has a forming shoulder or is designed in the form of a forming shoulder, which forms or has a forming section with a contour extending substantially transversely to the material flow direction and having a substantially convex shape and a tubular section with a contour extending substantially transversely to the material flow direction and having a substantially concave shape, wherein in particular the forming section and the tubular section merge into one another along a preferably spatial forming edge, and wherein the forming section and the tubular section of the forming shoulder are arranged relative to one another in such a way thatthat in the material flow direction, the flat web, starting from the transport roller in an at least approximately flat state, first comes into contact with the forming section in a first transport direction and then, over the forming edge, in an at least partially rolled-up state, comes into contact with the tubular section in a second transport direction, wherein furthermore the first and the second transport direction enclose an angle which lies between 71° and 120° (71 to 120 degrees), in particular between 71° and 90° (71 and 90 degrees), and furthermore in particular is at least approximately 90° (90 degrees), wherein in particular the forming shoulder comprises a right and a left front shoulder element and a right and a left rear shoulder element, wherein the shoulder elements are arranged relative to one another in such a way that the flat web, starting from the transport roller and viewed in the material flow direction,first comes into contact with the front shoulder elements and then comes into contact with the rear shoulder elements, and wherein the shoulder elements are in particular individually adjustable, and further wherein in particular the shoulder elements are adjustable such that a length of the forming edge is variable.,

[0033] The flat web structuring device is particularly designed to introduce a three-dimensional structure into the flat web. In particular, it is designed to emboss a structure into the flat web. The structure introduced into the flat web by the flat web structuring device changes the cross-section of the flat web, viewed in a plane that is oriented at least approximately perpendicular to a longitudinal direction of the flat web. In an initial state, i.e., before the flat web enters the flat web structuring device, the cross-section of the flat web is at least approximately rectangular. This shape is at least locally changed by the deformation process.For example, the deformation may be accompanied by a local reduction in the cross-section of the flat sheet; likewise, the deformation, again viewed in cross-section, may cause a local curvature, bulge or similar of the flat sheet, whereby a local reduction or even a local increase in the material thickness may also occur.

[0034] Advantageously, the flat web is guided by means of, over and / or along the transport roller, and in this way the web tension of the flat web is kept at a desired value. Alternatively or additionally, the flat web can be guided by means of, over or with the help of the transport roller. The transport roller acts as a guide for the spread out, i.e. not yet gathered or compacted, flat web. In contrast to a solution in which the flat web is deflected over a deflection edge or the like, thus maintaining the web tension, transporting the flat web by means of a transport roller prevents a reduction in abrasion on the flat web. This type of web guidance is particularly advantageous for a flat web that has been provided with an additive. This applies in particular to the case in which the additive is only applied to one side of the flat web.With the aid of the flat web preforming device mentioned, the flat web only comes into contact with the flat web preforming device with one of its two sides.

[0035] The angle ranges mentioned allow the flat web preforming device to be constructed particularly compactly.

[0036] According to a further advantageous embodiment, it is provided that the shoulder elements are each adjustable in a linear movement. Furthermore, it is provided in particular that the front shoulder elements are displaceable along front displacement directions, which lie in a plane perpendicular to a longitudinal axial direction of the tubular section and point towards a center of the tubular section, and wherein the rear shoulder elements are displaceable along rear displacement directions, and the rear displacement directions run obliquely to said plane and intersect at least approximately in a straight line defined by the longitudinal axial direction, wherein this intersection point lies outside the tubular section.

[0037] According to a further embodiment, the forming edge runs spatially, which means that it does not run completely within one plane.

[0038] The shoulder elements can be individually and independently adjustable. However, this is not mandatory. According to further embodiments, the shoulder elements can be adjusted in pairs, for example.

[0039] According to a further advantageous embodiment, it is provided that a length of the forming edge of the forming shoulder is between 100 mm and 400 mm, in particular between 100 mm and 300 mm, furthermore in particular between 100 mm and 180 mm, or between 180 mm and 300 mm.

[0040] The adjustability of the shoulder elements allows the forming shoulder to be flexibly adjusted to different requirements regarding strand forming. On the one hand, the forming shoulder can be adjusted to flat webs of different widths, and on the other hand, the forming shoulder can be adjusted to different desired diameters of the material strand to be produced. The tubular section of the forming shoulder is not necessarily designed in the form of a closed tube. In particular, it is intended that the tubular section does not have a completely closed outer surface. For example, the tubular section has a groove running along its longitudinal direction. The tubular section is, for example, cylindrical in shape, but can also be designed to be slightly conical.

[0041] While the previously mentioned embodiments carry out a forming or pre-forming of the flat web with the aid of a forming shoulder, according to further embodiments it is provided that the forming of the flat web takes place with the aid of a crowned roller.

[0042] Accordingly, according to a further advantageous embodiment of the machine of the tobacco processing industry, it is provided that the transport roller is a crowned roller and the flat web preforming device comprises at least one keyway roller, wherein in particular the keyway roller comprises cheeks forming the keyway, which are coupled to one another by a connecting shaft, wherein on the connecting shaft, in particular centrally between the cheeks, a support body is present, the cross section of which is larger than the connecting shaft.

[0043] The transport roller, designed as a crowned roller, serves, due to its more or less strongly convex shape, in particular also as a guide for the flat web. According to a further advantageous embodiment, it is further provided that the flat web preforming device comprises a first and a second key-groove roller, wherein the first and the second key-groove roller are arranged such that the first key-groove roller interacts with an underside of the flat web, with which the flat web is also guided over or along the transport roller, and the second key-groove roller interacts with an upper side of the flat web and is arranged in particular downstream of the first key-groove roller.

[0044] In this context, it is further provided, in particular, that the first keyway roller comprises a first support body and the second keyway roller comprises a second support body, wherein, viewed in a cross-section that intersects the respective connecting shaft centrally, the aspect ratio of height to width of the second support body is greater than that of the first support body. The second keyway roller thus has a support body that is narrower and taller than the support body of the first keyway roller. This supports the transverse gathering of the flat web. This allows the flat web to receive its final shape before it is fed into the inlet hopper of a format unit.

[0045] According to further exemplary embodiments relating to general configurations of machines in the tobacco processing industry, regardless of whether these comprise a forming shoulder or a crowned roller, it is further provided that the flat web is guided along the transport roller, advantageously tangentially or over a wrap angle greater than zero and / or less than 95 degrees. In other words, the flat web contacts the transport roller along a wrap angle that is greater than zero and less than 95 degrees. Furthermore, according to a further exemplary embodiment, it is provided that the transport roller is driven. Preferably, it is driven to rotate about a rotational axis. The transport roller is in particular driven such that it rotates at a peripheral speed that is equal to, lower than, or higher than the speed of the material flow.The drive of the transport roller can be used to optimize both the web tension of the flat web and the abrasion occurring on the transport roller in relation to the flat web.

[0046] The machine in the tobacco processing industry allows a flat web to be processed, whereby the web tension of the flat web can also be advantageously adjusted with regard to the desired application of the additive via the transport roller. With the help of the slot die, different additives such as gel, flavor, hot melt, etc. can be applied to the web-like material of the flat web. In order to achieve the right viscosity range for optimal application of the additive, the slot die can be designed to be heated. This allows the viscosity of the additive to be adjusted if it cannot be changed by corresponding additives. Some additives are solid at room temperature, for example as granules, or are highly viscous. Such additives cannot be conveyed or applied without being heated.For this reason, the tobacco processing machine can be equipped with an additive heating device. To ensure that the additive can be applied to the flat web with the desired viscosity, the wide slot die is also provided with a heating device.

[0047] The slot die can be designed as a contact slot die or as a contactless slot die. Using a contact slot die, the additive can be processed over a wide viscosity range without excess quantities. The slot die receives the additive, maintains it at the desired temperature or heats it to the required application temperature, and passes the additive on to the die gap, for example, via the storage chamber. A slot die enables homogeneous application of the additive through uniform transverse distribution and transfers the additive to the flat web. Using a slot die, additives can be advantageously processed over a wide viscosity range between 100 m Pa*s and 1600 m Pa*s. This provides a large process window for the application of the additive.The contact slot die is always in mechanical contact with the flat web and requires a certain amount of pressure. Adjusting the web tension using the transport roller is therefore particularly advantageous for this application.

[0048] According to a further embodiment, the slot die is designed as a contactless slot die. According to this embodiment, abrasion on the flat web is minimized or completely avoided, and no or very little dust is generated. The application of the additive can be assisted by compressed air, whereby the volume flow of the compressed air can be regulated and / or controlled to suit the additive, in particular its viscosity, and / or to suit the material of the flat web, for example its porosity or air permeability. The amount of compressed air is always adjusted so that overspray occurring due to possible atomization of the additive is kept as low as possible. To prevent the slot die from cooling down, a compressed air heater can be provided.

[0049] The object is further achieved by a method for producing paper filters using a machine in the tobacco processing industry for producing a strand from a flat web, wherein the machine comprises the following devices arranged one behind the other in a material flow direction: a flat web supply device which provides the flat web, a flat web structuring device, in particular a crimping device, with which a structure is introduced into the flat web, by means of which the flat web, in the spread-out state, receives a cross-section which is changed at least in sections, a flat web pre-forming device with which the flat web is converted into a pre-formed state, and a strand forming device with which the strand is produced from the pre-formed flat web, wherein this method is advantageously further developed in thatthat a transport roller is arranged between the flat web structuring device and the flat web preforming device, and the flat web is guided in the material flow direction by means of and / or along the transport roller, and the transport roller guides the spread-out flat web and / or adjusts a web tension of the flat web on a transport path between the flat web structuring device and the flat web preforming device, and between the flat web structuring device and the flat web preforming device, in particular between the flat web structuring device and the transport roller, an application device is arranged, which applies an additive, in particular a liquid, to at least one upper side of the flat web, which is opposite a lower side with which the flat web contacts the transport roller, wherein the application device comprises a slot die for applying the additive,and wherein the flat web is a paper web and paper filters are cut to length from the strand produced.,

[0050] The process for producing paper filters using a machine in the tobacco processing industry offers the same or similar advantages as those already mentioned with regard to the machine itself. The machine in the tobacco processing industry is particularly suitable for producing paper filters, as it is often desired to add an additive, such as a flavoring or ingredient, to the paper filter. Advantageously, a homogeneous application of the additive can be achieved, and the amount of additive that can be applied lies within a wide range of parameters.

[0051] According to further embodiments, the flat web is a web made of a nonwoven fabric, a flat web for producing so-called "tissue filters," or even a paper web that, in addition to paper, also comprises, particularly in small proportions, small parts made of PLA, reconstituted tobacco material (recon film), or other materials. This advantageously applies to all embodiments.

[0052] According to one embodiment, the method is advantageously further developed in that the application device comprises a compressed air-assisted slot die and the additive is applied to the flat web with the aid of compressed air, wherein heated compressed air is provided in particular to the slot die.

[0053] According to a further embodiment, the application device itself is heated. This makes it possible to apply all media that pass through the application device, including the slot die and any storage chambers or supply channels, at the desired temperature.

[0054] According to a further advantageous embodiment, the method is further developed in that the slot die comprises a die gap through which the additive is applied to the flat web and at least on one side of the die gap an air gap running at least approximately parallel to this is encompassed by the slot die, in particular a pair of air gaps running at least approximately parallel to this on both sides of the die gap are encompassed, wherein compressed air is guided through the at least one air gap for the compressed air-assisted application of the additive.

[0055] According to a further advantageous embodiment, the method is further developed in that the nozzle gap and / or the at least one air gap is / are adjusted, wherein in particular a length and / or a width of the nozzle gap and / or the at least one air gap is / are adjusted, and wherein furthermore in particular a width of the nozzle gap is between 5 μm and 1 mm, furthermore in particular between 10 μm and 500 μm. The further values ​​for the width of the nozzle gap mentioned with regard to the device can also be applied with regard to the method according to one embodiment.

[0056] According to a further embodiment, the method is further developed in that the slot die comprises a base body provided with a heater, wherein the base body comprises a storage chamber for the additive that communicates fluidically with the die gap, and the additive is temperature-controlled in the storage chamber, wherein in particular the slot die is heated by the heater to a temperature such that the additive has a viscosity that is between 50 m Pa*s and 1600 m Pa*s (milli Pascal second). The additive is, as already mentioned, brought to the desired temperature or kept at this temperature so that it is present at the die gap of the slot die with the desired viscosity, which enables optimal application of the additive.

[0057] According to a further advantageous embodiment, the slot die is designed as a contact slot die and applies the additive to the flat web using a contact process, or the slot die is designed as a contactless slot die and applies the additive to the flat web without contact. In particular, with contactless application, the additive is applied to the flat web from a distance of between 3 mm and 60 mm. The distance is also particularly between 5 mm and 50 mm, further particularly between 10 mm and 30 mm, further particularly between 15 mm and 50 mm, further particularly between 20 mm and 30 mm.

[0058] The object is further achieved by using a machine according to one or more of the aforementioned embodiments for producing paper filters. It is also intended that the machine be used for producing paper filter segments or other or similar rod-shaped articles for the tobacco processing industry.

[0059] The use of the machine also offers the same or similar advantages as those already mentioned with regard to the machine in the tobacco processing industry and the process for producing paper filters, so that repetition will be avoided.

[0060] Further features of the invention will become apparent from the description of embodiments of the invention together with the claims and the accompanying drawings. Embodiments of the invention may incorporate individual features or a combination of several features. The invention is described below, without limiting the general inventive concept, using exemplary embodiments with reference to the drawings. For all details of the invention not explained in more detail in the text, express reference is made to the drawings. They show:

[0061] Fig. 1 shows a machine of the tobacco processing industry for producing a strand from a flat web in a schematic view,

[0062] Fig. 2 a simplified perspective view of a forming shoulder,

[0063] Fig. 3 is a simplified front view of a forming shoulder, set up to produce a strand with a large cross-section,

[0064] Fig. 4 is a simplified front view of a forming shoulder, adjusted to produce a strand with a small diameter compared to the adjustment shown in Fig. 3,

[0065] Fig. 5 a simplified side view of a forming shoulder,

[0066] Fig. 6 is a simplified perspective view of part of a machine in the tobacco processing industry, which includes a keyway roller as a preforming device,

[0067] Fig. 7 is a simplified perspective view looking at the top of a flat web gathered with a keyway roller,

[0068] Fig. 8 is a simplified perspective view looking at an underside of the flat track,

[0069] Fig. 9 is a further simplified perspective detail view of a machine in the tobacco processing industry for producing a strand from a flat web, comprising a first and a second keyway roller as a flat web preforming device,

[0070] Fig.10 is a schematic side view of a detail of a machine of the tobacco processing industry, comprising a forming shoulder and an application device comprising a slot die,

[0071] Fig. 11 is a schematically simplified side view of the application device, comprising the slot die,

[0072] Fig. 12 is a schematically simplified detailed view of the machine of the tobacco processing industry in the area of ​​the application device, which comprises a wide slot nozzle designed as a contact application nozzle and

[0073] Fig. 13 is a schematically simplified detailed view of a wide slot die which operates contactless and is assisted by compressed air.

[0074] Within the scope of the invention, features marked with “in particular” or “preferably” are to be understood as optional features.

[0075] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a repeated presentation is omitted.

[0076] Fig. 1 shows a schematic representation of a machine 2 in the tobacco processing industry. With the help of this machine 2, a strand 6 is produced from a flat web 4. The machine 2 comprises a flat web supply device 8 for supplying the flat web 4. The flat web 4 is supplied, for example, on a reel 10. The flat web supply device 8 can be designed as a reel changer. According to such an embodiment, it has more than one holder for receiving a reel 10 and, for example, a corresponding splicing device which allows the individual flat webs 4 present on a reel 10 to be connected to one another to form an infinitely long flat web 4.

[0077] The flat web 4 is, for example, a paper web. However, the flat web 4 can also be a web made of a nonwoven, a flat web for producing so-called "tissue filters", or even a paper web which, in addition to paper, particularly in small proportions, comprises small parts made of PLA, reconstituted tobacco material (recon film), or other materials. The strand produced by the machine 2 is accordingly, for example, a paper strand that can be cut into rod-shaped articles 92 using a cutting device 90. The rod-shaped articles 92 are, for example, paper filters or paper filter segments.

[0078] Downstream in the material flow direction, the machine 2 comprises a flat web structuring device 12, which comprises, for example, two crimping rollers 14. With the help of the crimping rollers 14, a three-dimensional structure is introduced, in particular embossed, into the flat web 4. Still viewed in the material flow direction, the flat web 4 then passes via a dancer 16, which serves to maintain, control, or regulate the web tension, and various deflection rollers (not shown in more detail), to an application device 18. With the help of the application device 18, an additive 22 is applied, for example, sprayed, to an upper side 20 of the flat web 4. An opposite underside 21 remains unwetted. According to a further embodiment, the application device 18 is designed such that both the upper side 20 and the underside 21 of the flat web 4 can be wetted. The additive 22 is, in particular, a liquid.For applying the additive 22, the application device 18 comprises a slot die. The design of the slot die and the application device 18 are explained in detail below.

[0079] Subsequently, the flat web 4 provided with the additive 22, still viewed in the material flow direction, reaches a transport roller 24 and is introduced over or along the transport roller 24 into a flat web preforming device 26.

[0080] The transport roller 24 ensures that the flat web 4 is held under a suitable pre-tension. Maintaining a desired pre-tension is advantageous for treating the flat web 4 with the additive 22, since this ensures a homogeneous application of the additive 22. Furthermore, maintaining the desired pre-tension is advantageous in order to convert the flat web 4 into a pre-formed state in the flat web pre-forming device 26. Starting from the flat web pre-forming device 26, the pre-formed flat web 32 reaches a strand forming device 28 in a pre-formed state. For example, the strand forming device 28 is a format unit into which the pre-formed flat web 32 enters via an inlet hopper 30. In the format unit, the strand 6 is formed from the pre-formed flat web 32.

[0081] Rod-shaped articles 92 of the tobacco processing industry, for example filter rods or segments, can be cut to length from the strand 6 using the cutting device 90.

[0082] The lower section of Fig. 1 schematically illustrates a plan view of the flat web 4. While the flat web 4 is in its original width up to the flat web preforming device 26, it is formed in the flat web preforming device 26 from a gathered or, for example, cylindrical structure. This creates the preformed flat web 32, which is formed into a strand 6 in the strand forming device 28. Important for the forming process is the web tension of the flat web 4 at the inlet into the flat web preforming device 26. The transport roller 24 is provided in order to set the web tension to a desired value and also to maintain it, for example, within a specified value interval. The transport roller 24 also serves in particular to guide the flat web 4. The transport roller 24 is, for example, designed to be driven. The transport roller 24 can also be designed to rotate freely.If the transport roller 24 is driven, this drive can be controlled or regulated. For example, the speed of the transport roller 24 is adjusted to the web speed of the flat web 4, and the speed of the transport roller 24 is controlled or regulated accordingly to the web speed of the flat web 4. As a result, there is no or only minimal relative movement between a surface of the transport roller 24 and the flat web 4. Ideally, both surfaces move at the same speed. This largely prevents abrasion on the flat web 4, and the process dust that sometimes occurs is avoided or at least significantly reduced.

[0083] According to one embodiment, the flat web preforming device 26 is designed as a forming shoulder 36. This embodiment is explained in Figs. 2 to 5. According to another embodiment, the flat web preforming device 26 is designed as a keyway roller 38. This embodiment is explained in Figs. 6 to 9.

[0084] Fig. 2 shows a simplified perspective view of a forming shoulder 36. The forming shoulder 36 comprises a forming section 40 and a tubular section 42. Both sections are distributed over different components of the forming shoulder 36, as will be explained further below. The forming section 40 and the tubular section 42 merge into one another along a forming edge 44, for example a three-dimensional one. The forming edge 44 is three-dimensional in the sense that it does not lie or run in a single plane. The tubular section 42 is, for example, cylindrical, whereby a lateral surface or inner side of the tubular section 42 does not necessarily have to form a completely closed surface. For example, in an upper region of the tubular section 42, between the shoulder elements 50, 52, which are described in more detail below, there is a gap running in the longitudinal direction of the tubular section 42.

[0085] The forming section 40 and the tubular section 42 of the forming shoulder 36 are arranged relative to one another such that, in the material flow direction, the flat web 4, starting from the transport roller 24, first comes into contact with the forming section 40 in an at least approximately flat or planar state and in a first transport direction T 1. Subsequently, the flat web 4, passing over the forming edge 44 in an at least partially rolled-up state, comes into contact with the tubular section 42 in a second transport direction T2. ​​In the illustrated embodiment, the first transport direction T 1 and the second transport direction T2 enclose an angle which is at least approximately 90°.

[0086] The forming shoulder 36 comprises a right front shoulder element 46 and a left front shoulder element 48. The two front shoulder elements 46, 48 have curved outer surfaces, which form a partial region of the forming section 40 of the forming shoulder 36. The forming shoulder 36 further comprises a right rear shoulder element 50 and a left rear shoulder element 52. The rear shoulder elements 50, 52, in turn, have curved outer surfaces, which also form a partial region of the forming section 40 of the forming shoulder 36. Starting from the transport roller 24, the flat web 4, viewed in the material flow direction, which corresponds to the first transport direction T1, first comes into contact with the front shoulder elements 46, 48, more precisely their forming sections 40. A central region of the flat web 4 initially enters the tubular section 42 of the forming shoulder 36 beyond the forming edge 44.Downstream of the forming edge 44, the flat web 4 is transported in an at least partially rolled-up state in the second transport direction T2. ​​The side or edge regions of the flat web 4 come into contact further up with the rear shoulder elements 50, 52, more precisely their forming sections 40. In this upper region, the flat web 4 is formed into an at least approximately cylindrical body and conveyed in the direction of the second transport direction T2 through the tubular section 42. The side edges of the flat web 4 can overlap one another, lie abutting one another, or have a gap between them extending in the longitudinal direction of this cylindrical body.

[0087] The shoulder elements 46, 48, 50, 52 are jointly fastened to a flange 54. A guide element 56 is provided between the flange 54 and each of the shoulder elements 46, 48, 50, 52. In Fig. 2, only the right guide element, which holds the front right shoulder element 46, is visible. Furthermore, spacer elements are provided between the front and rear shoulder elements 46, 48 and 50, 52. A right spacer element 58 extends between the right front shoulder element 46 and the right rear shoulder element 50. This right spacer element 58 allows the forming edge 44 to be continuously extended between the right front shoulder element 46 and the right rear shoulder element 50. A left spacer element 60 is located on the opposite side.The left spacer element 60 extends between the left front shoulder element 48 and the left rear shoulder element 52 and continuously extends the forming edge 44 between these two shoulder elements 48, 52. Furthermore, a central spacer element 62 can be provided, which continuously extends the forming edge 44 between the right and left front shoulder elements 46, 48.

[0088] The spacer elements 58, 60, 62 are advantageously provided because the shoulder elements 46, 48, 50, 52 are individually adjustable. The shoulder elements 46, 48, 50, 52 are each adjustable in a linear movement. For this purpose, the shoulder elements 46, 48, 50, 52 are fastened to the associated guide element, for example, via a corresponding slotted hole connection 64. A scale can enable the adjustability of the shoulder elements 46, 48, 50, 52 along precisely defined adjustment paths. The shoulder elements 46, 48, 50, 52 are adjustable such that a length of the forming edge 44 can be changed. Accordingly, spacer elements 58, 60, 62 of different sizes can be provided in order to implement appropriate adjustment of the forming shoulder 36.

[0089] The front shoulder elements 46, 48 are displaceable along front displacement directions which lie in a plane perpendicular to a longitudinal axial direction L of the tubular portion 42.

[0090] One or more motorized drives may be provided to adjust the shoulder elements 46, 48, 50, 52, particularly all shoulder elements 46, 48, 50, 52. These drives, not shown, can be implemented with manageable technical effort due to the existing linear adjustability of the shoulder elements 46, 48, 50, 52. The shoulder elements 46, 48, 50, 52 can be individually adjustable independently of one another, either motorized or manually adjustable. Coupled adjustability can also be provided.

[0091] Fig. 3 shows a simplified front view of the forming shoulder 36, schematically illustrating a right front displacement direction 66, along which the right front shoulder element 46 is displaceable, and a left front displacement direction 68, along which the left front shoulder element 48 is displaceable. The two displacement directions 66, 68 point in the direction of an axis that coincides with the longitudinal axial direction L of the tubular section 42. They therefore point toward a center of the tubular section 42.

[0092] The rear shoulder elements 50, 52 are displaceable along rear displacement directions 70, 72, wherein these rear displacement directions 70, 72 extend obliquely to the aforementioned plane. In Fig. 3, a right rear displacement direction 70, in the direction of which the right rear shoulder element 50 is displaceable, and a left rear displacement direction 72, along which the left rear shoulder element 52 is displaceable, are indicated. The rear displacement directions 70, 72 intersect at least approximately in a straight line defined by the longitudinal axial direction L, wherein this intersection point lies outside the tubular section 42.

[0093] By shifting the shoulder elements 46, 48, 50, 52, the length of the forming edge 44 can be changed. While in Fig. 3 the forming edge 44 is comparatively large, in the illustration in Fig. 4, which shows a further simplified front view of the forming shoulder 36, the shoulder elements 46, 48, 50, 52 are shifted such that the length of the forming edge 44 is shorter. If the forming shoulder 36 is in the state shown in Fig. 4, for example, the flat web 4 can be pre-formed more intensively than in a situation in which the flat web 4 passes through the forming shoulder 36 in the state shown in Fig. 3. Furthermore, it is possible to process flat webs 4 of various widths. For example, with the setting of the forming shoulder 36 shown in Fig. 3, a rather wide flat web 4 is processed than is the case when the forming shoulder 36 is in the state shown in Fig. 4.The forming shoulder 36 can therefore be flexibly adjusted to flat webs 4 of different widths.

[0094] Fig. 5 shows a simplified side view of the forming shoulder 36. The first and second transport directions T1, T2 are illustrated, which at least approximately enclose an angle of 90°. The shoulder elements 46, 48, 50, 52 are in the state shown in Fig. 4, i.e., they have been moved so far that no spacer elements 58, 60, 62 are provided between the shoulder elements 46, 48, 50, 52. Also shown are the right front displacement direction 66 of the right front shoulder element 46 and the right rear displacement direction 70 of the right rear shoulder element 50.

[0095] According to a further embodiment, the flat web preforming device 26 used is not the forming shoulder 36 previously described in connection with Figs. 2 to 4, but a keyway roller 38.

[0096] Fig. 6 shows a simplified perspective view of a part of the machine 2, which comprises a keyway roll 38 as the pre-forming device 26. The flat web 4 passes through a pair of crimping rollers 14 as the flat web structuring device 12 and then reaches the transport roll 24 along the first transport direction T1. The transport roll 24 ensures the web tension required for the subsequent pre-forming of the flat web 4. Between the flat web structuring device 12 and the transport roll 24 is arranged the application device 18, with the aid of which the additive 22 is applied to the upper side 20 of the flat web 4. This application device 18 can also be designed such that both the upper side 20 and the underside 21 of the flat web 4 can be provided with the additive 22.

[0097] In the illustrated embodiment, the transport roller 24 is designed as a spherical roller 74. The flat web 4 runs over the transport roller 24 in the direction of the keyway roller 38, wherein the flat web 4 is now conveyed in the second transport direction T2. ​​The keyway roller 38 becomes the flat web preforming device 26 by folding or gathering the flat web 4 transversely to its longitudinal direction. The preformed flat web 32 then runs into an inlet hopper 30 of a format unit as a strand forming device 28 for further processing. The keyway roller 38 comprises a left and a right cheek 76, 78 forming the keyway. These are coupled and / or connected to one another via a connecting shaft 80.

[0098] The first transport direction T1 is the direction in which the flat web 4 is fed to the transport roller 24. The second transport direction T2 is the direction in which the at least partially gathered flat web 32 is conveyed downstream of the transport roller 24. The second transport direction T2 coincides, for example, with a longitudinal extension direction of the tubular section 42 of the forming shoulder 36.

[0099] In the embodiment shown in Fig. 6, the second transport direction T2 may coincide with a conveying direction of the shirred flat web 32 in the strand forming device 28. However, the second transport direction T2 and the conveying direction of the strand forming device 28 located downstream of the inlet hopper 30 may also differ slightly from each other.

[0100] An angle between the first and second transport directions T1, T2 is always determined in a common plane. If the two transport directions are placed together like vectors, for example, the tip of the vector for the first transport direction T1 is placed at the end of the vector for the second transport direction T2, the angle between the two directions should always be the smaller of the two possible angles.

[0101] According to one embodiment, it is impossible for the vector of the first transport direction T1 to collide with the vector of the second transport direction T2 from above. In other words, according to embodiments, the machine for the tobacco processing industry should be prevented from guiding the web from above.

[0102] Fig. 7 shows a further simplified perspective view of the area of ​​the machine 2 in the region of the keyway roller 38. Fig. 8 shows this situation with a view of the underside 21 of the flat track 4. A support body 82 is located centrally on the connecting shaft 80 connecting the cheeks 76, 78. This support body 82 is arranged centrally between the cheeks 76, 78 and is enlarged in cross-section compared to the connecting shaft 80. The support body 82 supports the gathering of the flat track 4.

[0103] Fig. 9 shows, in a further simplified perspective detail view, the machine 2 of the tobacco processing industry, wherein its flat web preforming device 26 comprises a first keyway roller 38a and a second keyway roller 38b. In principle, both keyway rollers 38a, 38b are designed like the previously described keyway roller 38. The first keyway roller 38a interacts with an underside 21 of the flat web 4, with which the flat web 4 is also guided over or along the transport roller 24. For example, the transport roller 24 is again a crowned roller 74. The second keyway roller 38b interacts with an upper side 20 of the flat web 4 and is arranged, for example, downstream of the first keyway roller 38a.

[0104] The first and second keyway rollers 38a, 38b can have differently shaped support bodies 82. For example, the second support body 82b, viewed in a plane in which the connecting shaft 80 extends, is designed such that its height-to-width aspect ratio is greater than the aspect ratio of the first support body 82a. In other words, the second support body 82b is taller and narrower than the first support body 82a. This different shape of the support bodies 82a, 82b contributes to the improved preforming of the flat track 4.

[0105] Fig. 10 is a schematically simplified side view of a detail of machine 2 in the tobacco processing industry. Machine 2 comprises a forming shoulder 36 as a flat web preforming device 26. Flat web 4, which is, for example, a paper web, is deflected into the first transport direction T1 via deflection rollers (not shown in more detail). Before flat web 4 enters flat web preforming device 26, it is guided past transport roller 24. Downstream of transport roller 24 is arranged application device 18, which comprises slot die 94 for applying additive 22. Additive 22 is fed to slot die 94 or application device 18 via an additive connection 96. Furthermore, application device 18 comprises a compressed air connection 98, with which application device 18 can be supplied with compressed air.

[0106] The application device 18 is mounted such that the additive 22 is applied to the flat web 4 in an additive application direction 100. The additive application direction 100 forms an angle with a perpendicular 102 perpendicular to the plane in which the flat web 4 extends. This angle between the additive application direction 100 and the perpendicular 102 shall be referred to as the application angle. The application device 18 is mounted such that the application angle is adjustable. Furthermore, a distance D between the slot die 94 and the flat web 4 is adjustable.

[0107] The application device 18 further comprises a slot die 94, which comprises a base body 104 in which a storage chamber 106 is located. The storage chamber 106 serves to hold the additive 22 supplied to the slot die 94 via the additive connection 96. A heater 108 further provided in the base body 104 allows the additive 22 to be tempered or maintained at a desired temperature.

[0108] Fig. 11 shows a schematically simplified side view of the application device 18. The slot nozzle 94 comprises the base body 104, in which the storage chamber 106 for the additive 22 is located and into which the heater 108, for example an electrical resistance heater, is integrated. The heater 108 serves to heat the additive 22, but also to heat the compressed air supplied via the compressed air connection 98. For further heating of the compressed air, a compressed air heater (not shown) can also be included in the machine 2. The additive 22 can also be preheated before it is supplied to the application device 18 via the additive connection 96. The heater 108 integrated into the base body 106 of the slot nozzle 94 therefore preferably serves to maintain the preset temperatures or, if necessary, to slightly adjust the temperatures.The wide-slot nozzle 94 can be, for example, a contact wide-slot nozzle or a contactless wide-slot nozzle. A contact wide-slot nozzle 94 is shown in the simplified schematic detail view of Fig. 12. The wide-slot nozzle 94 sits directly on the upper side 20 of the flat web 4, thus being in direct contact with it. Overspray can be prevented by using a contact wide-slot nozzle.

[0109] Fig. 13 shows a schematically simplified detailed view, with a frontal view of the slot die 94. The slot die 94 is a compressed air-assisted slot die 94. It comprises a nozzle gap 110 provided for the additive 22, which in the illustrated embodiment, for example, extends over the entire length of the slot die 94. On both sides of the nozzle gap 110, air gaps 112 extend at least approximately parallel to it, from which compressed air emerges to assist the application of the additive 22.

[0110] The distance D (see Fig. 10) between the nozzle gap 110 of the slot die 94 and the upper side 20 of the flat web 4 is, for example, between 3 mm and 60 mm. The heater 108 is configured to heat the additive to a temperature or to maintain it at that temperature such that the additive 22 has a viscosity between 50 mPa*s and 1600 mPa*s.

[0111] All mentioned features, including those revealed solely in the drawings as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Embodiments according to the invention may be fulfilled by individual features or a combination of several features. iste

[0112] 2 machines

[0113] 4 flat track

[0114] 6 strands

[0115] 8 Flat web supply device

[0116] 10 reels

[0117] 12 Flat web structuring device

[0118] 14 crimping rollers

[0119] 16 dancers

[0120] 18 Application device

[0121] 20 Top

[0122] 21 subpage

[0123] 22 Additive

[0124] 24 transport roller

[0125] 26 Flat web preforming device

[0126] 28 Strand forming device

[0127] 30 inlet funnels

[0128] 32 preformed flat sheets

[0129] 36 Form shoulder

[0130] 38 keyway roller

[0131] 38a first keyway roller

[0132] 38b second keyway roller

[0133] 40 forming section

[0134] 42 tubular section

[0135] 44 Forming edge

[0136] 46 right front shoulder element

[0137] 48 left front shoulder element

[0138] 50 right rear shoulder element

[0139] 52 left rear shoulder element

[0140] 54 flange

[0141] 56 Guide element

[0142] 58 right spacer element

[0143] 60 left spacer element 62 central spacer element

[0144] 64 slotted hole connection

[0145] 66 right front shift direction

[0146] 68 left front shift direction

[0147] 70 right rear shift direction

[0148] 72 left rear shift direction

[0149] 74 crowned roller

[0150] 76 left cheek

[0151] 78 right cheek

[0152] 80 connecting shaft

[0153] 82 support bodies

[0154] 82a first support body

[0155] 82b second support body

[0156] 90 cutting device

[0157] 92 rod-shaped article

[0158] 94 Wide slot nozzle

[0159] 96 additive connection

[0160] 98 Compressed air connection

[0161] 100 Additive application direction

[0162] 102 Lot

[0163] 104 basic bodies

[0164] 106 Pantry

[0165] 108 Heating

[0166] 110 nozzle gap

[0167] 112 Air gap

[0168] D Distance

[0169] L Longitudinal axial direction

[0170] T1 first transport direction

[0171] T2 second transport direction

Claims

A machine (2) of the tobacco processing industry for producing a strand (6) from a flat web (4), comprising the following devices arranged one behind the other in a material flow direction: a flat web supply device (8) for supplying the flat web (4), a flat web structuring device (12), in particular a crimping device, with which a structure can be introduced into the flat web (4), by means of which the flat web (4) in the spread-out state receives a cross-section which is changed at least in sections, a flat web pre-forming device (26) with which the flat web (4) can be transferred into a pre-formed state, and a strand forming device (28) with which the strand (6) can be produced from the pre-formed flat web (4), characterized in that a transport roller (24) is arranged between the flat web structuring device (12) and the flat web pre-forming device (26), and the flat web (4) is conveyed in the material flow direction by means of and / or is guided along the transport roller (24), and the transport roller (24) is set up and designed to guide the spread-out flat web (4) and / or to adjust a web tension of the flat web (4) on a transport path between the flat web structuring device (12) and the flat web preforming device (26), and an application device (18) is arranged between the flat web structuring device (12) and the flat web preforming device (26), in particular between the flat web structuring device (12) and the transport roller (24), which application device is set up to apply an additive (22) to at least one upper side (20) of the flat web (4), which is opposite a lower side (21) with which the flat web (4) contacts the transport roller (24), wherein the application device (18) comprises a slot die (94) for applying the additive (22).

2. Machine (2) according to claim 1, characterized in that the application device (18) comprises a compressed air-assisted wide slot nozzle (94).

3. Machine (2) according to claim 2, characterized in that the wide slot nozzle (94) comprises a nozzle gap (110) provided for the additive (22) and at least one air gap (112) running at least approximately parallel to the nozzle gap (110) on one side thereof, in particular a pair of air gaps (112) running at least approximately parallel to the nozzle gap (110) on both sides thereof.

4. Machine (2) according to one of claims 1 to 3, characterized in that the wide slot die (94) comprises a base body (104) provided with a heater (108), wherein in particular the base body (104) comprises a storage chamber (106) for the additive (22) which communicates fluidically with the die gap (110). includes.

5. Machine (2) according to claim 3 or 4, characterized in that the nozzle gap (110) and / or the at least one air gap (112) are / is adjustable, wherein in particular a length and / or a width of the nozzle gap (110) and / or the at least one air gap (112) are / is adjustable and wherein furthermore in particular a width of the nozzle gap is between 5 pm and 1 mm, furthermore in particular between 10 pm and 500 pm.

6. Machine (2) according to one of claims 2 to 5, characterized by a compressed air heater which is designed to provide heated compressed air to the slot die (94).

7. Machine (2) according to one of claims 1 to 6, characterized in that the wide slot nozzle (94) is designed as a contact wide slot nozzle or as a contactless wide slot nozzle, wherein in particular the contactless wide slot nozzle (94) is arranged such that a distance (D) between the flat web (4) and a nozzle gap (110) of the wide slot nozzle (94) is between 3 mm and 60 mm.

8. Machine (2) according to one of claims 1 to 7, characterized in that the slot die (94) is designed to process the additive (22) with a viscosity of between 50 m Pa*s and 1600 m Pa*s.

9. Machine (2) according to one of claims 1 to 8, characterized in that the flat web preforming device (26) has a forming shoulder (36) or is designed in the form of a forming shoulder (36) which has a forming section (40) with a contour extending substantially transversely to the material flow direction and substantially convexly shaped and a tubular- shaped section (42) with a contour extending substantially transversely to the material flow direction and having a substantially concave shape, wherein in particular the forming section (40) and the tubular section (42) merge into one another along a preferably spatial forming edge (44), and wherein the forming section (40) and the tubular section (42) of the forming shoulder (36) are arranged relative to one another in such a way that in the material flow direction, the flat web, starting from the transport roller (24), first comes into contact with the forming section (40) in an at least approximately flat state in a first transport direction (T1) and then comes into contact with the tubular section (42) over the forming edge (44) in an at least partially rolled-up state in a second transport direction (T2), wherein furthermore the first and the second transport direction (T1, T2) enclose an angle,which lies between 71° and 120°, in particular between 71° and 90°, and furthermore is in particular at least approximately 90°, wherein in particular the forming shoulder (36) comprises a right and a left front shoulder element (46, 48) and a right and a left rear shoulder element (50, 52), wherein the shoulder elements (46, 48, 50, 52) are arranged relative to one another in such a way that the flat web (4), starting from the transport roller (24) and viewed in the material flow direction, first comes into contact with the front shoulder elements (46, 48) and then comes into contact with the rear shoulder elements (50, 52), and wherein the shoulder elements (46, 48, 50, 52) are in particular individually adjustable, and furthermore wherein in particular the shoulder elements (46, 48, 50, 52) are adjustable in such a way that a length of the forming edge (44) is variable. Machine (2) according to one of claims 1 to 9, characterized inthat the transport roller (24) is a crowned roller (74) and the flat web preforming device (26) has at least one, A keyway roller (38), wherein in particular the keyway roller (38) comprises cheeks (76, 78) forming the keyway, which are coupled to one another by a connecting shaft (80), wherein a support body (82) is provided on the connecting shaft (80), in particular centrally between the cheeks (76, 78), the cross-section of which is larger than that of the connecting shaft (80). A method for producing paper filters using a machine (2) in the tobacco processing industry for producing a strand (6) from a flat web (4), wherein the machine (2) comprises the following devices arranged one behind the other in a material flow direction: a flat web supply device (8) which supplies the flat web (4), a flat web structuring device (12), in particular a crimping device, with which a structure is introduced into the flat web (4), by means of which the flat web (4) receives an at least partially modified cross-section in the spread-out state,a flat web preforming device (26) with which the flat web (4) is converted into a preformed state, and a strand forming device (28) with which the strand (6) is produced from the preformed flat web (4), characterized in that a transport roller (24) is arranged between the flat web structuring device (12) and the flat web preforming device (26), and the flat web (4) is guided in the material flow direction by means of and / or along the transport roller (24), and the transport roller (24) guides the spread-out flat web (4) and / or adjusts a web tension of the flat web (4) on a transport path between the flat web structuring device (12) and the flat web preforming device (26), and between the flat web structuring device (12) and the flat web preforming device (26), in particular between the flat web structuring device (12) and the transport roller (24), an application device (18) is arranged, which applies an additive (22) to at least one upper side (20) of the flat web (4), which is opposite a lower side (21) with which the flat web (4) contacts the transport roller (24), wherein the application device (18) comprises a slot die (94) for applying the additive (22), and wherein the flat web (4) is a paper web and paper filters are cut to length from the produced strand (6). Method according to claim 11, characterized in that the application device (18) comprises a compressed-air-assisted slot die (94), and the additive (22) is applied to the flat web (4) with the aid of compressed air, wherein heated compressed air is provided, in particular, to the slot die (94).Method according to claim 12, characterized in that the wide slot nozzle (94) comprises a nozzle gap (110) through which the additive (22) is applied to the flat web (4) and at least on one side of the nozzle gap (110) an air gap (112) running at least approximately parallel to this is enclosed by the wide slot nozzle (94), in particular a pair of air gaps (112) running at least approximately parallel to the nozzle gap (110) are enclosed on both sides thereof, wherein compressed air is guided through the at least one air gap for the compressed air-assisted application of the additive (22).Method according to claim 13, characterized in that the nozzle gap (110) and / or the at least one air gap (112) are / is adjusted, wherein in particular a length and / or a width of the nozzle gap (110) and / or the at least one air gap (112) are / is adjusted and wherein furthermore in particular a width of the nozzle gap is between 5 pm and 1 mm, furthermore in particular between 10 pm and 500 pm. Method according to one of claims 11 to 13, characterized in that the slot die (94) comprises a base body (104) provided with a heater (108), wherein the base body (104) comprises a storage chamber (106) for the additive (22) which communicates fluidically with the nozzle gap (110), and the additive (22) is tempered in the storage chamber (106), wherein in particular the slot die (94) is heated by the heater (108) to a temperature such that the additive (22) has a viscosity which is between 50 m Pa*s and 1600 m Pa*s.Method according to one of claims 11 to 15, characterized in that the slot die (94) is designed as a contact slot die and applies the additive (22) to the flat web (4) in a contact process, or the slot die (94) is designed as a contactless slot die and applies the additive (22) to the flat web (4) in a contactless manner, wherein, in particular in the case of contactless application, the additive (22) is applied to the flat web (4) from a distance of between 3 mm and 60 mm. Use of the machine (2) according to one of claims 1 to 11 for producing paper filters.

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