Flat web processing device having a dust reduction device, method for operating the flat web processing device, and rod-like article

Abstract

The invention relates to a flat web processing device (2) for the tobacco processing industry, having a rotatably mounted first roller (4) and a rotatably mounted second roller (6) which interacts with the first roller and is configured to process a provided flat web (8) in a roller gap (10) between the first and second rollers (4, 6) and to provide a processed flat web (12) downstream of the roller gap (10), characterised by a dust reduction device (14) which is configured to reduce dust particle emission of the flat web processing device (2) by interaction with the flat web (8) and / or the processed flat web (12).

Description

[0001] Flat web processing device with a dust reduction device, method for operating the flat web processing device and rod-shaped articles

[0002] Description

[0003] The invention relates to a flat web processing device for the tobacco processing industry, comprising a rotatably mounted first roller and a rotatably mounted second roller cooperating with it, which are configured to process a supplied flat web in a roller gap located between the first and second rollers and to provide a processed flat web downstream of the roller gap. The invention further relates to a machine for the tobacco processing industry with such a flat web processing device, as well as a method for operating the flat web processing device and a method for operating the machine for the tobacco processing industry. The invention also relates to the use of a machine and a rod-shaped article for the tobacco processing industry.

[0004] In the tobacco processing industry, various process steps generate significant amounts of dust. Depending on the material being processed, this dust might be tobacco dust or paper dust, for example. Fibers, such as those from paper or filter tow, are also considered dust particles. A common technical objective is to reduce dust particle emissions from the process or the machinery used in it. Reducing dust particle emissions is often undertaken to improve the production environment with regard to occupational safety. However, this is not the only goal. Dust emissions are also reduced to minimize the amount of dust introduced into the production process, thus keeping the dust content in the finished product as low as possible.Another goal pursued in reducing dust particle emissions is to protect the machines used for processing from excessive contamination or to remove contaminants, so that consistently high quality can always be maintained.

[0005] In the processing of filter tow for the production of filters for filter cigarettes, transport rollers are used to convey the filter tow. To remove filter tow residue from these transport rollers, a cleaning device is known from EP 2 080440 B1. This device has a doctor blade with an integrated compressed air channel. This cleaning device is used, for example, to clean the stretching rollers used in filter tow processing. The document further mentions that these rollers can be cleaned with a doctor blade that incorporates a suction air channel. Filter tow residue loosened from the roller by the doctor blade can be extracted and removed via this channel.

[0006] A similar device for cleaning roller surfaces is known from DE 100 50 974 A1. A scraper removes adhering substances from the roller surface, which are then carried away by an airflow directed through a suction nozzle into an extraction duct. The prior art documents cited as examples are representative of the technical principle that has become established for cleaning rollers in the tobacco processing industry. A mechanical cleaning device, such as a scraper, abrasive, or a brush, loosens or removes contaminants adhering to the roller surface. It has become established technical knowledge that mechanical contact between the cleaning device and the contaminated surface is essential to achieve the desired cleaning performance. A corresponding cleaning device is also known from EP 1 314 363 A1.

[0007] Document EP 1 625797 A2 pursues a very similar technical approach for a cleaning device used to remove fiber debris from a suction belt. The suction belt is used, for example, to transport tobacco material or filter material. The cleaning device has a scraper edge that is cleaned of accumulating contaminants by a stream of compressed air.

[0008] From the field of paper processing, a stranding machine is known from DE 102005 046 885 A1, in which a paper web, used to wrap a filter material, is guided along a deflecting roller. A scraper and a suction device are provided on this deflecting roller to keep it free of contaminants. The scraper comes into direct mechanical contact with the deflecting roller and thus removes adhering contaminants.

[0009] The examples mentioned above from the processing of filter tow, tobacco material, and paper are representative of the established technical principles in the tobacco processing industry. When processing flat material in the tobacco processing industry, the transport or processing rollers are always cleaned with a brush or scraper that is in direct contact with the outside of the roller. This loosens contaminants, which are then vacuumed up.It is an object of the invention to provide a flat web processing device, a machine for the tobacco processing industry, a method for operating the flat web processing device and a method for operating the machine, the use of such a machine and a rod-shaped article for the tobacco processing industry, wherein dust particle emission from the flat web processing device, the machine or the method is to be reduced, a lower dust particle emission is to occur when using the machine and the rod-shaped article is to be producible with lower dust particle emission.

[0010] The problem is solved by a flat web processing device for the tobacco processing industry comprising a rotatably mounted first roller and a rotatably mounted second roller cooperating with it, wherein the flat web processing device is further developed to process a roller gap located between the first and the second roller by means of a provided flat web and to provide a processed flat web downstream of the roller gap, characterized by a dust reduction device which is designed to reduce dust particle emissions from the flat web processing device by interaction with the flat web and / or the processed flat web.

[0011] The flat web processing device is based on the technical premise that dust particle emissions during the processing of flat webs in the tobacco industry can be significantly reduced if, unlike the previously common practice, the contaminants are removed not from the processing rollers, but from the (unprocessed) flat web and / or the processed flat web itself. It is a technical misconception, substantiated by the extensive prior art presented in the introduction (and represented by several documents), that dust particles generated during the processing of flat webs in the tobacco industry can only be reduced by removing these particles directly from the processing rollers.Part of this technical misconception is the assumption that cleaning the roller surfaces always requires mechanical contact between a cleaning element, such as a scraper or brush, and the roller surface. The particles loosened in this way can then be removed with a suction air stream. However, the prior art does not eliminate the need for mechanically removing the particles from the roller surface.

[0012] Contrary to this entrenched technical prejudice, which can be demonstrated in the prior art, the technical implementation of the flat web processing device according to aspects of the invention takes a different approach. A dust reduction device is described that reduces dust particle emissions through direct interaction with the flat web and / or the processed flat web.

[0013] According to one embodiment, the dust reduction device includes an extraction device. The extraction device is capable of generating a particle transport flow that interacts with the flat web, the processed flat web, or both. This dust particle transport flow ensures that dust particles are removed from the flat web and / or the processed flat web, thereby reducing dust particle emissions from the flat web processing device.

[0014] According to an advantageous embodiment, the extraction device is designed to reduce dust particle emissions from the flat web processing device, particularly through interaction exclusively with the processed flat web. The extraction device is further designed to reduce dust particle emissions by extracting dust in an area close to the web. Furthermore, the extrusion device is designed to reduce the number of particles on the processed flat web by the interaction of a particle transport flow entering the extraction device with the processed flat web.

[0015] By reducing the number of particles on the processed flat web, the overall dust particle emission from the flat web processing equipment can be reduced. This is because dust particles from the processed flat web often escape into the surrounding atmosphere and disperse there. Reducing the dust particle concentration on the processed flat web also contributes to a lower dust particle concentration in the rod-shaped article produced from that web.

[0016] A near-web area, in which the extraction device is located or arranged, is characterized by the fact that the particle transport flow entering the extraction device is strong enough at the point where the flat web is being processed to remove particles adhering to it, possibly entrain them, and feed them into the extraction device. The specific dimensions of the near-web area can therefore depend, at least in part, on the strength of the particle transport flow entering the extraction device. Generally, a near-web area will extend at a distance of a few millimeters to centimeters from the web. The specified distance refers to the distance between an inlet opening of the extraction device and a surface of the flat web being processed.It is particularly intended that the flow velocity and / or volume per unit time of the particle transport flow be adjusted to the properties of the processed flat web. The particle transport flow strength determined in this way must not be so high that damage to the processed flat web is to be expected. According to a further embodiment, the extraction device is also provided to have at least one extraction funnel opening in the direction of the processed flat web.

[0017] For example, a central axis of the extraction funnel points perpendicularly to a surface of the machined flat surface, meaning that this central axis extends in a direction parallel to a surface normal of the machined flat surface. The central axis of the extraction funnel is, for instance, an axis around which the funnel-shaped section of the extraction funnel extends symmetrically. However, the extraction funnel can also be oriented at an angle to the surface normal. The chosen orientation of the extraction funnel determines the efficiency of dust particle extraction.

[0018] According to a further embodiment, the flat web processing device is further developed in that the extraction device has at least one particle transport flow auxiliary nozzle which is arranged and configured to emit an air jet which serves to generate or at least support the particle transport flow directed towards the extraction funnel, wherein the particle transport flow auxiliary nozzle is arranged on a side of the processed flat web opposite the extraction funnel.

[0019] The particle transport flow is specifically generated or supported by the air jet produced by the auxiliary nozzle. By positioning the auxiliary nozzle and the extraction funnel on opposite sides of the processed flat web, particles adhering to the web can be efficiently removed.

[0020] The extraction funnel is, for example, a rectangular funnel, and the auxiliary nozzle is, for example, a flat jet nozzle. The respective longitudinal directions of extension of the rectangular funnel or the flat jet nozzle run transversely to a longitudinal direction or transport direction of the processed flat web. Similar to an air curtain, the flat air jet can uniformly remove the dust particles from the flat web. The opposite and appropriately oriented rectangular funnel can collect these particles. The longitudinal directions of extension of the rectangular funnel and the flat jet nozzle extend transversely, in particular perpendicularly, to a surface normal of the processed flat web and also transversely, in particular perpendicularly, to a transport direction or longitudinal direction of the processed flat web.

[0021] According to a further embodiment, the extraction device includes an extraction table arranged below the processed flat web. An extraction table generates a uniform and gentle airflow that serves as a particle transport flow or at least supports it. The processed flat web can be cleaned of particles particularly gently. Furthermore, due to the large surface area of ​​the extraction table, there is a high probability that any particles detached from the flat web will also be captured by it.

[0022] According to a further embodiment, the extraction device comprises an extraction roller whose outer surface is provided with a plurality of extraction openings, wherein the extraction roller is in particular arranged such that its outer surface extends in a web-adjacent area at the point nearest to the processed flat web and / or is in contact with the processed flat web.

[0023] The nearest point on the surface of the suction roller is the point, or technically speaking, the small area of ​​the surface, that is closest to the processed flat web. For example, the distance between the nearest point and the processed flat web is a few millimeters or centimeters.

[0024] A dust reduction device with a suction roller is advantageous because it allows dust particles to be removed directly from the processed flat web. In other words, dust particle removal is very efficient. The suction roller rotates at the same speed as the processed flat web. In other words, the tangential speed at the outer surface of the suction roller is at least approximately equal to the transport speed of the processed flat web in contact with the outer surface of the suction roller. To ensure the suction roller rotates at the desired speed, it can be equipped with a drive. It is also possible for the suction roller to rotate passively.This requires a correspondingly smooth-running bearing for the suction roller, so that its rotation can be effected, for example, by the low frictional force between the conveyed flat web and the outer surface of the suction roller. Furthermore, a proportionality factor can be incorporated between the speed of the processed flat web and the rotational speed of the suction roller, which can be used to optimize the extraction of dust particles from the processed flat web.

[0025] Advantageously, the particles are removed from the processed flat web using the suction roller, without any loss of speed of the conveyed flat web, without it being subjected to excessive mechanical stresses, or without the risk of the processed flat web being sucked into the suction device.

[0026] The suction roller has numerous suction openings on its outer surface. These suction openings can be, for example, bores. Alternatively, the suction roller can be provided with a grid structure on its outer surface, so that the suction openings are provided by the corresponding openings in the grid structure. The particle transport flow passes through the suction openings into the interior of the suction roller. The size of the suction openings can be selected to effectively prevent the processed flat web from being drawn into the interior of the suction roller. The dimensions of the suction openings, viewed on the outer surface of the suction roller, are, for example, in the range of a few millimeters. As mentioned previously, it is advantageous that no relative movement takes place between the outer surface of the suction roller and the surface of the processed flat web.This ensures low mechanical stress on the flat web, while simultaneously allowing loose fibers or particles present on the surface of the processed flat web to be detached and removed. In the context of this description, both fibers and particles will be generally referred to as "dust particles" or "particles." The particles are conveyed through the suction openings by the particle transport stream into the interior of the suction roller or adhere to the outer surface of the suction roller. To remove the particles adhering to the outer surface of the suction roller, a further suction device or a scraper device can be provided on the suction roller.

[0027] The suction roller can further include a flow control device designed such that the particle transport flow only passes through a portion of the suction openings. For example, the flow control device, which may be a shielding plate or similar device located inside the suction roller, can close off the portion of the suction openings located in a circumferential section of the suction roller facing away from the processed flat web. The particle transport flow thus only reaches those suction openings located in a circumferential section of the suction roller facing the processed flat web. Since no particle transport flow passes through the suction openings facing away from the web, particles or fibers adhering to the outer surface of the suction roller can be removed in this area.Furthermore, the flow control device can be used to reduce the airflow required for the operation of the suction roller.

[0028] The extraction openings in the outer surface of the extraction roller can be dimensioned to effectively prevent the processed flat web from being drawn in. As will be explained in more detail below, the processed flat web can be, for example, a crimped flat web or a flat web cut into individual strips. Especially in the latter case, it is important that the processed flat web, in the form of individual strips, is not drawn into the extraction roller. If, for example, the material width of the individual strips is X mm, the dimension of the extraction openings can be, for example, X / 2, X / 3, X / 4, or X / 5 mm, i.e., half, one-third, one-quarter, or one-fifth of the strip width.

[0029] The suction roller provides particle extraction in a web-adjacent area. Direct contact with the processed flat web represents the minimum extent of this web-adjacent area. Therefore, it is intended that there is mechanical contact between the outer surface of the suction roller and the processed flat web, or that the suction roller extends into a web-adjacent area; in other words, the outer surface of the suction roller is located at its nearest point in the web-adjacent area, for example, a few millimeters away from the processed flat web.

[0030] The aforementioned design of the suction roller with a flow control device, which ensures that the suction openings are only controlled in a section of the circumference so that the particle transport flow passes through them, has the further advantage that, in the unlikely event that one of the strips of the processed flat web is drawn into the suction roller, the adhesive force on the strip only acts up to that section of the suction roller's circumference where the particle transport flow is still present. In other words, if the strip reaches the area of ​​the suction roller's circumference facing away from the processed flat web (where there is no longer a particle transport flow through the suction openings), the strip detaches itself from the suction roller and returns to the material flow. Such a design of the suction roller advantageously improves production reliability.Additionally, a scraper can be provided on the circumferential section of the suction roller facing away from the flat web for the aforementioned purpose. The suction roller makes it possible to pick up and / or extract particles directly from the processed flat web. Unlike a suction funnel, no minimum distance to the processed flat web needs to be maintained, especially if the processed flat web is in the form of separate strips. The risk of sucking in the processed flat web or the strips is significantly lower with the suction roller than with conventional solutions.

[0031] According to a further embodiment, the extraction device is arranged in an area in which the processed flat web is guided at least approximately in a horizontal transport direction.

[0032] Such an arrangement of the extraction device is particularly advantageous for the aforementioned embodiments, which relate to the design of the extraction device with an extraction funnel, an extraction table and / or an extraction roller.

[0033] According to a further advantageous embodiment, the flat web processing device is further developed in that the extraction device has a first extraction funnel which is arranged above the first and second rollers, and / or a second extraction funnel which is arranged below the first and second rollers.

[0034] The first and / or second extraction funnels can be trough-shaped or rectangular funnels, the longitudinal direction of which runs in the direction of the axes of rotation of the first and second rollers. The axes of rotation of the rollers lie, for example, in a horizontal plane. The first and / or the second extraction funnel are arranged on opposite sides of this horizontal plane or above and below this horizontal plane. According to a further advantageous embodiment, the flat web processing device is further developed by an enclosure in which at least the first and the second rollers are arranged.

[0035] By arranging the two rollers used for processing the flat web within an enclosure, dust emissions from the rollers can be contained within the enclosure's limited area. The enclosure is particularly advantageous when combined with an extraction system. For this purpose, an extraction system can be provided, for example, to generate a particle transport flow within the enclosure, continuously changing the atmosphere inside. In other words, the extraction system is designed to remove dust particles from the enclosure.

[0036] According to an advantageous embodiment, the enclosure has a feed opening through which the flat web can be fed into the enclosure and a discharge opening through which the processed flat web can be fed out of the enclosure, wherein at least one air curtain is provided at the discharge opening, which is arranged and configured to generate an air curtain that at least partially closes the discharge opening.

[0037] The use of at least one air curtain prevents dust particles from escaping the enclosure through the discharge opening. Dust particles could be carried along by the movement of the processed flat web and an airflow generated in its immediate vicinity, thus escaping the enclosure. The air curtain effectively prevents this. For example, multiple air curtains can be provided. A first air curtain can create an air curtain directed towards the top of the processed flat web, while a second air curtain can create a second air curtain directed towards the underside of the processed flat web. Furthermore, it is possible, for example, to provide one or more air curtains not only at the discharge opening but also at the feed opening. The air curtains can be generated, for example, using suitable flat jet nozzles.

[0038] According to a further advantageous embodiment, the flat web processing device is further developed by a blowing device for generating a blowing air stream, which is arranged and configured to direct the blowing air stream opposite to a transport direction of the processed flat web, in particular at an acute angle, onto the processed flat web.

[0039] The blow-off device allows for the targeted removal of dust particles from the processed flat web. For this purpose, it is advantageous if the blow-off device is located within the enclosure. Furthermore, it is advantageous if dust particle extraction from the enclosure is also provided; in other words, the dust reduction device additionally includes an extraction system designed to remove dust particles from the enclosure. The blow-off device can at least partially function as an air curtain. The air curtain and blow-off device can complement each other advantageously. While the blow-off device ensures that dust particles are removed from the processed flat web, the air curtain prevents them from escaping the enclosure.

[0040] According to a further advantageous embodiment, the flat web processing device is further developed in that the dust reduction device is configured to reduce dust particle emissions from the flat web processing device by interacting with the flat web, wherein the dust reduction device in particular

[0041] a) has a flat web moistening device which is configured to moisten the flat web upstream of the roll gap and / or

[0042] b) has a flat web heating device which is designed to heat the flat web upstream of the roller gap.

[0043] Both the flat web humidification device and the flat web heating device interact directly with the flat web. Unlike most of the previously mentioned extraction devices, however, they do not interact with the processed flat web, but rather with the unprocessed flat web. In the context of this description, the unprocessed flat web is simply referred to as the "flat web." Through their interaction with the flat web, both devices ensure that the intensity of dust particle emissions is reduced during processing. In other words, the generation of dust particles is reduced. Heating the flat web material before processing makes its fibers more flexible, which reduces dust generation. Humidifying the flat web prevents dust particles from detaching from the web and entering the surrounding atmosphere.

[0044] The flat web humidification device is designed, for example, to wet the flat web with a liquid. This device is, for instance, a spray chamber through which the flat web is fed. The humidification material can be, for example, water or another liquid. The amount of liquid applied can be controlled and / or regulated, for example, via feedback. A material moisture sensor can be used to measure the moisture content of the flat web downstream of the humidification device. The amount of liquid applied can then be adjusted based on the sensor reading.

[0045] Alternatively or additionally to a spray chamber, a mist chamber can be used, in which a liquid is finely atomized and through which the flat web is passed. During this passage, the flat web absorbs the moisture present in the mist chamber. The mist chamber can be controlled in a similar manner to the spray chamber described earlier. Based on the reading from a humidity sensor, the quantity or density of the atomized liquid in the mist chamber can be adjusted so that the flat web reaches the desired material moisture content.

[0046] The flat web moistening device can apply the liquid to the web by contact application. For example, the web material can be guided along a perforated tube filled with liquid. A film of liquid is present on the outer surface of the perforated tube, which can be absorbed by the web. A roller can also be used to apply the liquid, with or without pressure. For example, a sponge roller or similar can be used. Liquid application can also be achieved using a porous roller, such as a guide roller, which is filled with liquid from the inside. The liquid exits through openings in the outer surface of such a porous guide roller.

[0047] The aforementioned flat web humidification devices can be implemented individually or in combination. They can be arranged within the flat web processing device. An alternative arrangement of the flat web humidification device, for example upstream of the flat web processing device, is also possible and is explained in more detail below.

[0048] According to a further advantageous embodiment, the dust reduction device includes an electrostatic particle collection device. An electrostatic particle collection device ionizes the dust particles or fibers present on one side of the flat web or the processed flat web, for example, by a corona discharge. The electrostatic particle collection device can be implemented with either active or passive ionizers. The ionized dust particles detach from the device without requiring any mechanical contact between, for example, a scraper or brush and the flat web or the processed flat web. The dust particles or fibers are thus separated from the flat web or the processed flat web without contact and can be easily extracted from the surface of the flat web or the processed flat web using a suction device.The electrostatic particle collection device can advantageously be combined with a suction device.

[0049] The electrostatic particle collection device can be arranged both upstream and downstream of the roller pair. Dust particles can be removed from either the flat web or the processed flat web. Alternatively, an electrostatic particle collection device can be provided both upstream and downstream of the roller pair.

[0050] According to a further advantageous embodiment, it is further provided that the first and / or the second roller are connected to the extraction device as a dust reduction device, wherein the first and / or the second roller are designed and arranged to generate a particle transport flow in the roller gap, which is directed from the roller gap into an interior of the first and / or second roller, wherein the first and / or the second roller are provided with extraction openings on their outer surfaces.

[0051] According to this embodiment, the dust particles are extracted into an interior space within the rollers used to process the flat web. In this way, the dust particles can be removed directly at their source. This design is particularly advantageous when the first and second rollers are crimping or cutting rollers, as dust particles are generated during both the crimping and cutting processes.

[0052] According to a further embodiment, it is further provided that the first and second rollers are crimp rollers and the processed flat web is a crimped flat web, the first and second rollers are embossing rollers and the processed flat web is an embossed flat web, or the first and second rollers are cutting and / or separating rollers for separating the flat web into at least partially separate strips and the processed flat web is a plurality of strips.

[0053] As mentioned previously, both crimping and cutting a flat web are associated with the generation of dust particles, so it is particularly advantageous to reduce the process dust generated during these processes.

[0054] The problem is further solved by a machine for the tobacco processing industry, comprising a flat web supply device, a flat web processing device according to one or more of the aforementioned embodiments, and a strand forming device. The flat web supply device is configured to supply the flat web to the flat web processing device, and the flat web processing device is configured to supply the processed flat web to the strand forming device. The strand forming device, in turn, is configured to form a strand for the tobacco processing industry by further processing the processed flat web.

[0055] Advantageously, the machine used in the tobacco processing industry produces less process dust because the dust particle emission from the flat web processing device is reduced. A further advantage is that the produced strand also contains fewer dust particles than with conventional machines. According to another embodiment of the machine used in the tobacco processing industry, which also represents an independent solution to the problem according to the invention, the machine is designed as follows:

[0056] The tobacco processing machine comprises a flat web supply device, a flat web processing device, and a strand forming device. The flat web processing device has a rotatably mounted first roller and a rotatably mounted second roller interacting with it. These rollers are configured to process a supplied flat web in a roller gap located between the first and second rollers and to supply a processed flat web downstream of the roller gap. The flat web supply device is configured to supply the flat web to the flat web processing device, and the flat web processing device is configured to supply the processed flat web to the strand forming device. The strand forming device is configured to form a strand for tobacco processing by further processing the processed flat web.This machine is further developed by a dust reduction device which is configured to reduce dust particle emissions from the machine by interacting with the flat web and / or the processed flat web, wherein the dust reduction device is configured to reduce dust particle emissions from the flat web processing device by interacting with the flat web, and wherein the dust reduction device has a flat web moistening device which is configured to moisten the flat web upstream of the flat web processing device, in particular on a transport section between the flat web supply device and the flat web processing device.

[0057] In other words, the web moistening device is positioned between the web supply device and the web processing device, and is therefore not part of the web supply device itself. Such a machine offers the same or similar advantages as those already mentioned.

[0058] The problem is further solved by a method for operating a flat web processing device of the tobacco processing industry according to one or more of the aforementioned embodiments, wherein the dust reduction device reduces dust particle emissions from the flat web processing device by interaction with the flat web and / or the processed flat web.

[0059] Furthermore, the problem is solved by a method for operating a machine of the tobacco processing industry as described in the aforementioned embodiments, wherein the flat web supply device provides the flat web to the flat web processing device and the flat web processing device provides the processed flat web to the strand forming device, and wherein the strand forming device further processes the processed flat web and forms a strand of tobacco processing industry.

[0060] The same or similar advantages apply to the method for operating the flat web processing device and the method for operating the machine of the tobacco processing industry as have already been mentioned with regard to the flat web processing device and the machine of the tobacco processing industry itself, so repetition is unnecessary.

[0061] The problem is further solved by using a tobacco processing industry machine according to one or more of the aforementioned embodiments for the production of rod-shaped segments, products and / or articles of the tobacco processing industry, in particular segments in heat-not-burn articles.

[0062] The use of the machine is advantageous because the quality of the aforementioned items is improved when they contain fewer dust particles.

[0063] Finally, the problem is solved by a rod-shaped article for the tobacco processing industry, comprising at least one rod-shaped segment produced by cutting a strand to length, wherein this strand is produced using a machine according to one or more of the aforementioned embodiments. The rod-shaped article can be qualitatively improved because it contains fewer dust particles than conventional rod-shaped articles.

[0064] Further features of the invention will become apparent from the description of embodiments according to the invention, together with the claims and the accompanying drawings. Embodiments according to the invention may fulfill individual features or a combination of several features.

[0065] The invention is described below, without limiting the general concept, with reference to exemplary embodiments and the drawings, whereby for all details of the invention not explained in detail in the text, explicit reference is made to the drawings. The drawings show:

[0066] Figs. 1 to 3 are simplified perspective views of a flat web processing device;

[0067] Fig. 4 shows a schematic representation of an air curtain in a cross-sectional view;

[0068] Fig. 5 shows a schematic representation of a humidification device;

[0069] Fig. 6 a simplified perspective view of a suction roller; Fig. 7 a simplified cross-sectional view of a suction roller known from Fig. 6 in the plane AA;

[0070] Fig. 8 shows a schematic representation of a machine in the tobacco processing industry with a flat web processing device.

[0071] Within the scope of the invention, features marked with "in particular" or "preferably" are to be understood as optional features.

[0072] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a re-presentation is omitted.

[0073] Fig. 1 shows a simplified perspective view of a flat web processing device 2 for the tobacco processing industry. This device comprises a first rotatably mounted roller 4 and a second rotatably mounted roller 6 that interacts with it. The first roller 4 is rotatably mounted about a first axis of rotation D1, and the second roller 6 is rotatably mounted about a second axis of rotation D2. A flat web 8 is fed to the flat web processing device 2, for example, from a flat web supply device, which is not shown in Fig. 1. The flat web 8 passes through various deflection rollers and devices for adjusting or maintaining web tension, such as dancers, and enters a roller gap 10. The first and second rollers, 4 and 6, interact with each other in the area of ​​the roller gap 10, thus enabling the flat web 8 to be processed.Downstream of the roller gap 10, there is therefore a machined flat web 12.

[0074] The first and second rollers 4, 6 are collectively referred to as a roller pair. The rollers 4, 6 are, for example, crimp rollers. The processed flat web 12 is accordingly a crimped flat web. Crimp lines or crimp kinks are introduced into the flat web 8 along its longitudinal direction by means of the crimp rollers, so that the crimped flat web 12 can be more easily gathered transversely to its longitudinal direction. In Fig. 1, the crimp lines present in the processed flat web 12 are schematically indicated in a short section of the processed flat web 12 downstream of the roller gap 10. For the sake of clarity, the crimp lines are not shown further downstream, but are merely indicated by dots. According to another embodiment, the first and second rollers 4, 6 are embossing rollers. The embossing rollers can be designed, for example, as described in the context of application DE 102020 107421 of the same applicant.The embossing rollers are designed to imprint a three-dimensional shape onto the flat web 8. The processed flat web 12 is accordingly an embossed flat web. According to a further embodiment, the first and second rollers 4, 6 are cutting rollers and / or separating rollers for separating the flat web 8 into separate strips. A plurality of separate strips produced by separating the flat web 8 shall also be referred to as the processed flat web 12 in the context of this description. The individual strips that form the processed flat web 12 are indicated in Fig. 1 downstream of the roller gap 10 by longitudinally extending strips. The rollers 4, 6 can be disc cutters with which the flat web 8 is cut into separate individual strips. Such a disc cutter can, for example, be designed as disclosed in DE 1 954036 A1.The rollers 4, 6 can also be configured as described in DE 102018 106826. Accordingly, this is a separating device with which immediately adjacent strips are separated from one another along a predetermined separation line within a working area. The separation of the adjacent strips is achieved by stretching the flat web 8 transversely to the intended separation line so strongly that it tears apart along the separation line. The separation of the flat web 8 into strips can be intermittent in both cases. This means that adjacent strips are or remain connected to one another via webs or bridges extending transversely to the longitudinal direction of the processed flat web 12.

[0075] The flat web processing device 2 provides the processed flat web 12 (i.e., for example, a crimped or embossed flat web or a plurality of strips) to a downstream extrusion device in which further processing steps are carried out.

[0076] The flat web processing device 2 includes a dust reduction device 14, which is configured to reduce dust particle emissions from the flat web processing device 2 through interactions with the flat web 8 and / or the processed flat web 12. The dust reduction device 14 interacts directly with the flat web 8 and / or the processed flat web 12 to effect the corresponding reduction in dust particle emissions. Various embodiments of the dust reduction device 14 are described below.

[0077] According to one group of embodiments, the dust reduction device 14 is designed as an extraction device 16. In Fig. 1, such an extraction device 16 is indicated schematically, for example, by an upward-pointing arrow. The extraction device 16 can be designed and configured to extract dust particles from an enclosure. Technically, such an extraction device 16 can be designed, for example, as follows: An extraction duct is connected to the enclosure, into which a blower is integrated downstream. The blower conveys the exhaust air, thereby carrying away the dust particles present in the exhaust air. These can be removed from the exhaust air using a suitable dust separator.

[0078] The dust reduction device 14 can have a suitable enclosure 18, which is shown schematically with a dashed line in Fig. 1. At least the first and second rollers 4, 6 are arranged in the enclosure 18. The extraction device 16 removes the air contaminated with dust particles, which is contained within a spatially limited area by the enclosure 18. The enclosure 18 and the extraction device 16 together thus form the dust reduction device 14.

[0079] The flat web processing device 2 has a housing 20. This can also function as an enclosure 18. By using the extraction device 16 to extract the air from the housing 20 of the flat web processing device 2, which acts as an enclosure 18, it is possible to prevent the air contaminated with dust particles from spreading from the flat web processing device 2 into the production environment.

[0080] The housing 20 of the flat web processing device 2 has a feed opening 22 through which the flat web 8 is fed. The processed flat web 12 leaves the flat web processing device 2 through a discharge opening 24 located in the housing 20. To prevent the air containing dust particles from escaping the housing 20, which serves as an enclosure 18, an air curtain 26 is located at the discharge opening 24. The air curtain 26 is arranged and configured to close the discharge opening 24 with an air curtain, or to ensure that the dust particles do not leave the enclosure 18 due to the air curtain. By way of example, Fig. 1 shows an air curtain 26 that generates a first air curtain directed towards the upper side of the processed flat web 12. A second air curtain 26 generates a second air curtain directed towards the opposite underside of the processed flat web 12.An air curtain 26 (not shown in Fig. 1) or several air curtains can also be provided at the supply opening 22. The at least one air curtain acts as a dust reduction device 14. Advantageously, the air curtain works in conjunction with an extraction device 16, which extracts the dust particles from the housing 18.

[0081] Fig. 4 shows an air curtain 26 and another air curtain 26' in a schematic cross-sectional view. The processed flat web 12 is guided through the air curtain. The path of an airflow generated by the air curtains 26, 26' is indicated by arrows. The boundary between the flat web processing device 2 and a further unit downstream in the production process is shown by a dashed line. The air curtains 26, 26' are shown as an example of a part of the flat web processing device 2.

[0082] Another embodiment of a dust reduction device 14 is the extraction device 16 shown in Fig. 1, which has a particle transport flow auxiliary nozzle 28 and an extraction funnel 30. The particle transport flow auxiliary nozzle 28 is arranged and configured to emit an air jet, this air jet serving to generate or at least support a particle transport flow PT directed towards an extraction funnel 30. The particle transport flow auxiliary nozzle 28 is, by way of example, arranged on the upper side of the processed flat web 12. Opposite this, on the underside of the processed flat web 12, the extraction funnel 30 is arranged. The extraction funnel 30 is part of an extraction device 16 and is, for example, connected to an extraction duct (not shown).With the aid of the particle transport flow PT generated by the particle transport flow auxiliary nozzle 28, particles or fibers can be detached from the processed flat web 12 and conveyed towards the extraction funnel 30.

[0083] To increase the efficiency of such an extraction device 16, a further extraction device 16', arranged, for example, in a mirror image, can be provided, which is located downstream. A further particle transport flow auxiliary nozzle 28' is located on the underside of the processed flat web 12. The associated further extraction funnel 30' is located on the top side of the processed flat web 12. With this further extraction device 16', a further particle transport flow PT' flowing in the opposite direction can be generated.

[0084] Fig. 2 shows another flat web processing device 2 according to further embodiments. The dust reduction device 14 is shown by way of example as an extraction device 16 and has an extraction funnel 30 arranged above the rollers 4, 6. Additionally or alternatively, another extraction funnel 30' can be arranged below the rollers 4, 6. This is also connected to a corresponding extraction device 16. With the aid of the extraction funnels 30, 30', dust particles that arise in the roller gap 10 during the processing of the flat web 8 can be efficiently captured and conveyed away. The two extraction funnels 30, 30' open in the direction of the processed flat web 12 and in the direction of the flat web 8 that is fed into the roller gap 10, respectively.

[0085] A further extraction device 16, serving as a dust reduction device 14, has an extraction table 32 as shown in the embodiment illustrated in Fig. 2. The extraction table 32 is arranged below the machined flat web 12. With the aid of the extraction table 32, a uniform particle transport flow PT can be generated over a large area. Dust particles can be extracted from the machined flat web 12.

[0086] Furthermore, Fig. 2 shows a blow-off device 34, which also acts as a dust reduction device 14. The blow-off device 34 generates a blow-off airflow, which is schematically represented as a double arrow. The blow-off device 34 is arranged and configured to generate a blow-off airflow whose direction is oblique and opposite to a transport direction T of the processed flat web 12. The blow-off airflow is directed towards the upper side of the processed flat web 12. By way of example, another blow-off device 34' is also provided, which generates a blow-off airflow directed towards the underside of the processed flat web 12. The blow-off airflow strikes, for example, the upper or underside of the processed flat web 12 at an acute angle.

[0087] Fig. 3 shows a further embodiment of a flat web processing device 2. The flat web processing device 2 shown has a dust reduction device 14, which is exemplified as a suction roller 36.

[0088] The suction roller 36 is shown in a perspective detail view in Fig. 6. Fig. 7 shows a cross-section through the suction roller 36 along the plane AA shown in Fig. 6. The suction roller 36 has a plurality of suction openings 40 in its outer surface 38, of which only some are labeled for clarity. A particle transport flow PT flows through the suction openings 40. The particle transport flow PT conveys particles from the processed flat web 12 into an interior of the suction roller 36. From the interior of the suction roller 36, the particles are carried by the particle transport flow PT to a suitable collection device, where the dust particles are separated from the airflow. The suction roller 36 can be equipped with a flow control device 42.This ensures that the particle transport flow PT flows only through a portion of the extraction openings 40, and not through all of them. The flow control device 42 allows the particle transport flow PT to flow through a circumferential section of the extraction roller 36 that faces the processed flat web 12. In Fig. 6, these extraction openings 40 are shown as circles. The extraction openings 40 indicated by crosses are blocked by the flow control device 42, so that no particle transport flow PT flows through them. The flow control device 42 is, for example, a sheet metal plate or the like arranged inside the extraction roller 36. Furthermore, a scraper 44 is provided, which can be used to remove any deposits that may be present on the outer surface 38 of the extraction roller 36.

[0089] The lateral surface 38 extends at its nearest point into a region 41 close to the track. The lateral surface 38 can be in contact with the machined flat track 12. It can also be provided that the lateral surface 38 is located at its nearest point to the machined flat track 12 in the region 41 close to the track, but is not in contact with it. The region 41 close to the track extends, for example, a few millimeters to centimeters from the top surface of the machined flat track 12, in a direction that is at least approximately perpendicular to this top surface.

[0090] The aforementioned extraction devices are located, for example, in an area where the processed flat web 12 is conveyed at least approximately in a horizontal transport direction T. The extraction devices 16 are based on the interaction between the particle transport flow PT and the flat web 8 or the processed flat web 12. The particle transport flow PT enters, for example, the extraction funnels 30, 30', the extraction table 32, or the interior of the extraction roller 36.

[0091] The flat web humidification device 46 and / or the flat web heating device 48, schematically depicted in Fig. 3, can also be used as dust reduction devices 14. These two devices serve alternatively or simultaneously as dust reduction devices 14, which are designed to reduce dust particle emissions from the flat web processing device 2 by interacting with the flat web 8. The devices are each arranged upstream of the roll gap 10. Heating the flat web 8 makes it more supple, so that fewer dust particles are generated during processing in the roll gap 10. Humidifying the flat web 8 has a similar effect. Both the humidification and the heating of the flat web 8 can be controlled and / or regulated by feedback. For this purpose, a corresponding sensor 50 is provided with which the humidity and / or temperature of the flat web 8 can be measured.

[0092] Another possibility for implementing a dust reduction device 14 is an electrostatic particle collection device 52. Advantageously, such an electrostatic particle collection device 52 can be combined with an extraction device.

[0093] Fig. 5 shows an example of a flat web humidification device 46 in a schematically simplified cross-sectional view. The flat web 8 is guided around two deflection rollers 54 and around a tube 56, which has openings at its outlet end. As indicated by the arrows, moisture or liquid can exit from these openings and be absorbed by the flat web 8. The web can be guided alternatively along the two possibilities shown in Fig. 5.

[0094] According to a further embodiment, the dust reduction device 14 is implemented by connecting the first and / or the second roller 4, 6 to an extraction device 16. This is shown schematically in Fig. 3. The first and / or the second roller 4, 6 are accordingly designed and configured to generate a particle transport flow PT in the roller gap 10, which is directed out of the roller gap 10 and into an interior space of the first and / or the second roller 4, 6. For this purpose, the first and / or the second roller have extraction openings on their respective outer surfaces. If the first and second roller 4, 6 are crimping rollers or cutting rollers, the extraction openings can be arranged in those areas of the outer surface that are recessed from an outer casing of the roller. In other words, the extraction openings are located, for example, in the grooves, e.g.at the bottom of the groove, between the individual knives or projections of the rollers 4, 6. Fig. 8 shows a machine of the tobacco processing industry 60. The machine 60 has a flat web supply device 62, with which the flat web 8 is supplied, for example, from a bobbin 64. The flat web supply device 62 can be equipped with a bobbin changer so that the flat web 8 can be supplied as an endless flat web. Downstream of the flat web supply device 62, there is, by way of example and as an option, a storage device 66 with which the flat web 8 can be temporarily stored. Further downstream, a flat web processing device 2 is arranged, which can be designed according to one or more of the previously mentioned embodiments. The processed flat web 12 leaves the flat web processing device 2 in the direction of a downstream extrusion device 68.The strand forming device 68 is designed to form a strand 70 for the tobacco processing industry by further processing the processed flat web 12. For this purpose, the strand forming device 68 has functional units known per se, such as an infeed hopper 72 and a formatting unit 74. The tobacco processing machine 60 can also have a cutting device (not shown) with which individual rod-shaped segments 76 can be cut from the strand 70. These rod-shaped segments 76 can be combined or processed with further segments, as schematically shown, to form a rod-shaped article for the tobacco processing industry 78.

[0095] All features mentioned, including those discernible from the drawings alone as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Inventory embodiments may be fulfilled by individual features or a combination of several features. Reference numerals

[0096] 2 flat web processing devices

[0097] 4 first roller

[0098] 6 second roller

[0099] 8 Flat track

[0100] 10 roller gap

[0101] 12 processed flat track

[0102] 14 Dust reduction device 16 Extraction device

[0103] 16' additional extraction device

[0104] 18 Enclosure

[0105] 20 cases

[0106] 22 Inlet opening

[0107] 24 Collection opening

[0108] 26 Air curtain

[0109] 26' further air curtain

[0110] 28 Particle transport flow - Auxiliary nozzle 28' further particle transport flow - Auxiliary nozzle 30 Suction funnel

[0111] 30' further extraction funnel

[0112] 32 Extraction table

[0113] 34 Blow-out device

[0114] 34' further blow-off device

[0115] 36 Suction roller

[0116] 38 Surface area

[0117] 40 Extraction opening

[0118] 41 area near the railway

[0119] 42 Flow control device

[0120] 44 scrapers

[0121] 46 Flat-track humidification device

[0122] 48 Flat track heating device

[0123] 50 Sensor

[0124] 52 electrostatic particle collection device 54 deflection rollers

[0125] 56 pipe

[0126] 60 Machine of the tobacco processing industry 62 Flat web supply device

[0127] 64 Bobbins

[0128] 66 Storage device

[0129] 68 Extrusion forming device

[0130] 70 strands

[0131] 72 inlet funnels

[0132] 74 format unit

[0133] 76 Segment

[0134] 78 articles from the tobacco processing industry

[0135] D1 first axis of rotation

[0136] D2 second axis of rotation

[0137] T Transport direction

[0138] PT particle transport flow

Claims

Flat web processing device with a dust reduction device, method for operating the flat web processing device and rod-shaped articles Patent claims 1. Flat web processing device (2) of the tobacco processing industry, comprising a rotatably mounted first roller (4) and a rotatably mounted second roller (6) cooperating with it, which are configured to process a provided flat web (8) in a roller gap (10) located between the first and the second roller (4, 6) and to provide a processed flat web (12) downstream of the roller gap (10), characterized by a dust reduction device (14) which is configured to reduce dust particle emission from the flat web processing device (2) by interacting with the flat web (8) and / or the processed flat web (12).

2. Flat web processing device (2) according to claim 1, characterized in that the dust reduction device (14) has a suction device (16).

3. Flat web processing device (2) according to claim 2, characterized in that the extraction device (16) is configured to reduce dust particle emission from the flat web processing device (2) by interaction with the processed flat web (12), wherein the extraction device (16) is in particular configured to reduce particles on the processed flat web (12) by extraction in a web-adjacent area and by interaction of a particle transport flow (PT) flowing into the extraction device (16) with the processed flat web (12).

4. Flat web processing device (2) according to claim 3, characterized in that the extraction device (16) has at least one extraction funnel (30) opening in the direction of the processed flat web (12).

5. Flat web processing device (2) according to claims 3 and 4, characterized in that the extraction device (16) has at least one particle transport flow auxiliary nozzle (28) which is arranged and configured to discharge an air jet which serves to generate or at least support the particle transport flow (PT) directed towards the extraction funnel (30), wherein the particle transport flow auxiliary nozzle (28) is arranged on a side of the processed flat web (12) opposite the extraction funnel (30).

6. Flat web processing device (2) according to claim 2 or 3, characterized in that the extraction device (16) has an extraction table (32) arranged below the processed flat web (12).

7. Flat web processing device (2) according to claim 2 or 3, characterized in that the extraction device (16) comprises an extraction roller (36) whose outer surface (38) is provided with a plurality of extraction openings (40), wherein the extraction roller (36) is in particular arranged such that its outer surface (38) extends in a web-near area at the point nearest to the processed flat web (12) and / or is in contact with the processed flat web (12).

8. Flat web processing device (2) according to one of claims 3 to 7, characterized in that the extraction device (16) is arranged in an area in which the processed flat web (12) is guided at least approximately in a horizontal transport direction (T).

9. Flat web processing device (2) according to claim 2, characterized in that the extraction device (16) has a first extraction funnel (30) which is arranged above the first and second rollers (4, 6) and / or a second extraction funnel (30') which is arranged below the first and second rollers (4, 6).

10. Flat web processing device (2) according to one of claims 1 to 9, characterized by an enclosure (18) in which at least the first and the second roller (4, 6) are arranged.

11. Flat web processing device (2) according to claim 10, characterized in that the housing (18) has a feed opening (22) through which the flat web (8) can be fed into the housing (18), and a discharge opening (24) through which the processed flat web (12) can be discharged from the housing (18), wherein at least one air curtain (26) is provided at the discharge opening (24), which is arranged and configured to generate an air curtain that at least partially closes the discharge opening (24).

12. Flat web processing device (2) according to claims 2 and 10, characterized in that the extraction device (16) is configured to extract dust particles from the housing (18).

13. Flat web processing device (2) according to one of claims 1 to 12, characterized by a blow-out device (34) for generating a blow-out air stream, which is arranged and configured to direct the blow-out air stream opposite a transport direction (T) of the processed flat web (12), in particular at an acute angle, onto the processed flat web (12).

14. Flat web processing device (2) according to claim 1, characterized in that the dust reduction device (14) is configured to reduce dust particle emission from the flat web processing device (2) by interacting with the flat web (8), wherein the dust reduction device (14) in particular a) comprising a flat web moistening device (46) which is configured to moisten the flat web (8) upstream of the roller gap (10). and / or b) has a flat web heating device (48) which is configured to heat the flat web (8) upstream of the roller gap (10).

15. Flat web processing device (2) according to claim 1, characterized in that the dust reduction device (14) has an electrostatic particle collection device (52).

16. Flat web processing device (2) according to claim 2, characterized in that the first and / or the second roller (4, 6) are connected to the extraction device (16) as a dust reduction device (14), wherein the first and / or the second roller (4, 6) are designed and configured to generate a particle transport flow (PT) in the roller gap (10), which is directed from the roller gap (10) into an interior of the first and / or second roller (4, 6), wherein the first and / or the second roller (4, 6) are provided with extraction openings (40) on their outer surfaces (38).

17. Flat web processing device (2) according to one of claims 1 to 16, characterized in that the first and second rollers (4, 6) are crimp rollers and the processed flat web (12) is a crimped flat web, the first and second rollers (4, 6) are embossing rollers and the processed flat web (12) is an embossed flat web, or the first and second rollers (4, 6) are cutting and / or separating rollers for separating the flat web (8) into at least partially separate strips and the processed flat web (12) is a plurality of strips.

18. Machine (60) of the tobacco processing industry, comprising a flat web supply device (62), a flat web processing device (2) according to any one of claims 1 to 17 and a strand forming device (68), wherein the flat web supply device (62) is configured to supply the flat web (8) to the flat web processing device (2), and the flat web processing device (2) is configured to supply the processed flat web (12) to the strand forming device (68), and wherein the strand forming device (68) is configured to form a strand (70) of the tobacco processing industry by further processing the processed flat web (12).

19. Method for operating a flat web processing device (2) of the tobacco processing industry according to one of claims 1 to 17, wherein the dust reduction device (14) reduces dust particle emission from the flat web processing device (2) by interaction with the flat web (8) and / or the processed flat web (12).

20. Method for operating a machine (60) of the tobacco processing industry according to claim 18, wherein the flat web supply device (62) supplies the flat web (8) to the flat web processing device (2) and the flat web processing device (2) supplies the processed flat web (12) to the strand forming device (68), and wherein the strand forming device (68) further processes the processed flat web (12) and forms a strand (70) of the tobacco processing industry.

21. Use of a machine (60) according to claim 18 for the production of rod-shaped segments (76), products and / or articles of the tobacco processing industry (78), in particular segments in heat-not-burn articles.

22. Rod-shaped article (78) of the tobacco processing industry, comprising at least one rod-shaped segment (76) which is produced by cutting a strand (70) to length, wherein the strand (70) is produced using a machine (60) according to claim 18.

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