EP4116244A1 - Device and method for the tobacco processing industry for connecting two sheets of material - Google Patents

Abstract

The invention relates to a device 2 and a method in the tobacco processing industry for connecting two webs of material 4, 6. The device 2 for connecting a first porous web of material 4, which runs out in a conveying direction T, to a second porous web of material 6, comprises a cutting device 16 for cutting a free, trailing end 18 of the first web of material 4 and a free, leading end 20 of the second web of material 6, and also a connecting device 22 for connecting the free end 18 of the first web of material 4 to the free end 20 of the second web of material 6 to form an endless web of material 24 Formation of an overlapping area 26 extending transversely to the conveying direction over a width B of the endless web of material 24. The cutting device 16 is set up to produce two different cutting paths, in such a way that at the free end 18 of the first web of material 4 there is a first cutting path, de r is not complementary to a second cutting path generated at the free end 20 of the second material web 6 . The connecting device 22 is set up to connect the free ends 18, 20 of the webs of material in such a way that there is at least one opening 32 in the overlapping region 26 across the width B of the endless web of material 24. The connecting device 22 comprises an adhesive application device 48, which is set up to connect the free ends 18, 20 of the material webs 4, 6 to the free end 18 of the first material web 4 and/or the free end 20 of the second material web 6 with at least one adhesive pad 40 without carrier material to bring up.

Description

The invention relates to a device in the tobacco processing industry for connecting a first porous material web running out in a conveying direction to a second porous material web, comprising a cutting device for cutting a free, trailing end of the first material web and a free, leading end of the second material web and a Connecting device for connecting the free end of the first web of material to the free end of the second web of material to form an endless porous web of material, forming an overlapping region extending transversely to the conveying direction over a width of the endless web of material, the cutting device also being set up to produce two different cutting paths , such that at the free end of the first web of material there is a first incision that is not complementary to a second incision made at the free end of the second web of material, and wherein the V connection device is set up to connect the free ends of the material webs in such a way that in the overlapping area there is at least one opening across the width of the endless web of material.

Furthermore, the invention relates to a method for connecting a first porous material web running out in a conveying direction to a second porous material web, comprising the following steps: cutting a free, trailing end of the first material web and a free, leading end of the second material web with a cutting device, Connecting the free end of the first web of material to the free end of the second web of material to form an endless porous web of material with a connecting device, forming an overlapping area that extends transversely to the conveying direction over a width of the endless web of material, with the cutting device producing two different cuts in such a way that at the free end of the first web of material there is a first incision that is not complementary to a second incision made at the free end of the second web of material, and the free ends of the webs of material are such verb and that there is at least one opening in the overlapping area over the width of the endless web of material

Devices and methods for connecting two webs of material of finite length are used in the tobacco processing industry above all when endless webs of material are to be made available in order to maintain the production of endless strands without interruption. This applies, for example, to the manufacture of tobacco rods, filters or filter rods, but also to the manufacture of so-called heat-not-burn products, i.e. products that are heated but not burned during consumption. The finitely long webs of material are usually available on bobbins. Before a first material web present on a first reel is completely unwound and the reel runs empty, a second material web present on a second reel is positioned in the same conveying direction as the first material web. The two webs of material, more precisely the trailing one free end of the first web of material, which is still in production, and the leading free end of the new web of material, which is still almost completely on the second bobbin, are aligned with one another, cut and then joined together to form an endless web of material. Production is then continued with the second web of material on the second bobbin, which is then also transported in the conveying direction. Additional webs of material are reconnected to the web of material that is being discharged in the manner described, so that a continuous production process is ensured. The cutting and joining of finite webs of material to form an infinitely long web of material is also referred to as "splicing".

Due to the high production speed of modern machines in the tobacco processing industry, the bobbins sometimes run empty at relatively short intervals. The splicing of the material webs as well as the bobbin change therefore take place fully automatically in many cases. A device for attaching strip material from a spool to the strip material from an empty spool is already disclosed, for example DE 31 40 768 A1 out. With the machine known from this document, two webs of strip material, which are adjacent to one another on their end faces, ie butt, are connected to one another by a continuous adhesive tape running transversely to the longitudinal direction of the webs. The adhesive tape connects the large flat sides of the two strips on one side.

In such a device, the webs of material are cut at right angles, ie transversely to the conveying direction of the webs of material, and connected to one another. Should differ from DE 31 40 768 A1 the use of an adhesive strip can be avoided, it is also known to connect webs of material to one another in an overlapping area. The webs of material can be connected to one another without the use of auxiliary materials, for example by moistening and pressing or embossing. a device, with which such a type of connection between two webs of material can be produced is, for example, from DE 10 2014 018 818 A1 known.

An endless web of material, which is joined together from two overlapping webs of material or in which the two webs of material are connected to one another with a continuous adhesive strip, inevitably has an excess of material in the connection area between the two flat webs. This excess material is caused either by the adhesive tape applied to connect the flat webs or by the overlapping area in which the flat web is present twice due to the overlapping of the first and second flat webs. The overlapping area extends over the full width of the web of material, which can lead to a sudden and jerky thickening in the production process, for example of a strand produced with the aid of the endless flat web. Such a thickening has to be transported through a format, for example, which can lead to corresponding problems, including tearing of the strand to be formed or of the endless web of material. In order to make the material accumulation or thickening less jerky and sudden, it is also known not to make the cuts perpendicular to the conveying direction, but at an acute angle to it. The thickening that occurs can thus be distributed over a larger longitudinal area of the material web. A corresponding device with which such a connection between two flat webs can be realized is from DE 10 2014 018 818 A1 known. With a diagonal cut, the double layer of material is distributed over a longer distance in the conveying direction due to the triangular free ends. Nevertheless, the endless web of material is thicker in the overlapping area. So there is still an accumulation of material.

The cut edges of the webs of material produced with the aforementioned devices are always form-fitting. The tracks complement each other when the cut edges are butt pushed in front of each other in the plane of the material webs (i.e. without overlapping each other), in their form to a closed surface. Such a fit of the cut edges should also be referred to as shape-complementary.

In order to avoid an increase in mass or thickening in the connection area between a first and a second web of material, the proposes EP 3 757 046 A1 proposed to provide at least one opening in the overlapping area. A connecting station of the device known from this document is designed in such a way that the accumulation of material in the overlapping area is reduced and ideally completely avoided. The technical disadvantages associated with a thickening of the material web in the overlapping area can be overcome. The two webs of material are connected without adhesive, for example by moistening and then pressing and possibly additional heating of the connection area.

Such a device is preferably suitable for connecting material webs containing tobacco material. The situation is different with porous webs of material. In the context of the present description, a porous web of material should be understood to mean a web of material which is at least partially air-permeable. Such webs of material are processed, for example, for the production of paper filters. Conventional devices are only suitable for connecting such webs to a very limited extent.

It is an object of the invention to specify a device and a method in the tobacco processing industry for connecting a first porous material web to a second porous material web.

The object is achieved by a device in the tobacco processing industry for connecting a first porous material web, which runs out in a conveying direction, to a second porous material web, the device comprising: a cutting device for cutting a free, trailing end of the first material web and a free, leading end of the second material web and a connecting device for connecting the free end of the first material web to the free end of the second material web to form an endless material web, forming a transverse to the conveying direction over a width of endless material web extending overlapping area, wherein the cutting device is also set up to produce two different cutting paths, such that at the free end of the first material web there is a first cutting path that is not complementary to a second cutting path created at the free end of the second material web, and wherein the Connecting device is set up to connect the free ends of the material webs in such a way that in the overlapping area across the width of the endless material web there is at least one opening, the device being further developed in that the connecting device comprises an adhesive application device which is set up to apply at least one adhesive pad without carrier material to the free end of the first material web and/or the free end of the second material web in order to connect the free ends of the material webs.

The configuration of the device according to the invention is based on the finding that porous webs of material, ie webs made of a material which has a certain air permeability, can be connected very well with the aid of adhesive pads. The webs of material are in particular paper-like webs of material. Furthermore, in particular, the webs of material are free of tobacco material. The joining techniques known from the prior art, for example those in which the material is moistened and then possibly pressed under the action of heat, always require that the webs of material to be joined have the property of adhering to one another when they are moistened. This is generally not the case with paper-like material webs, which is why an adhesive-free connection can only be realized in a few cases. Embossing or knurling is one way of connecting webs of material without adhesive. These connection techniques have turned out to be unsuitable for porous materials.

It was also found that applying an adhesive pad is far superior to other adhesive application techniques for porous materials and is therefore advantageous. For example, it can advantageously be avoided that the adhesive penetrates through the porous web of material. Such an effect would make further processing of the endless web of material produced more difficult and, under certain circumstances, would require cleaning of the connecting device.

It has also proven to be advantageous to use an adhesive pad without carrier material, since otherwise the carrier material also contributes to the increase in mass in the connection area between the material webs. Unlike a double-sided adhesive tape, for example, an adhesive pad without carrier material does not have a carrier arranged centrally between the adhesive layers.

In the context of the present description, an adhesive pad should be understood to mean a spatially limited, extended area in which an adhesive is present. In particular, the adhesive pad is inherently stable, i.e. it does not disintegrate under its own weight. An adhesive pad can be provided, for example, from a high or extremely viscous adhesive, a gel-like adhesive or a film-like adhesive, ie an adhesive present in the form of a thin layer.

The adhesive pad is preferably applied to the second web of material. This configuration of the device has proven to be particularly favorable in terms of process technology.

According to one embodiment, the device is developed in that the adhesive application device is set up to apply the adhesive pad from an adhesive transfer tape. The use of transfer adhesive tapes has proven to be particularly advantageous in practice. For example, these are readily available and can be exchanged quickly.

According to further embodiments, the adhesive application device is set up to apply hot glue or other liquid adhesives that are so viscous or even highly viscous that they do not penetrate the porous web of material. Such an adhesive application device comprises in particular a transfer roller which is set up to temporarily hold one or more adhesive pad(s) and to apply them to the first and/or second web of material. For this purpose, adhesive pads are applied to one or more transverse positions on this transfer roller by means of an adhesive supply device. The adhesive application device thus comprises an adhesive supply device, with the transfer roller and the adhesive supply device being set up such that one or more adhesive pad(s) can be applied to the transfer roller by the adhesive supply device at one or more transverse positions spaced apart from one another in the axial direction of the transfer roller.

The adhesive application device is also set up in such a way that the transfer roller can be moved between a pick-up position, in which the adhesive supply device applies the at least one adhesive pad to the transfer roller, and an application position. The direction of travel is in particular at least approximately parallel to the axial direction of the transfer roller.

The adhesive application device is also set up in particular to carry out a radial displacement movement of the transfer roller in the application position for applying the adhesive pads to the first and/or second web of material. The transfer roller can be moved radially (i.e. transversely to the axial direction of the transfer roller) by a certain amount, so that the transfer roller comes into contact with the material web and the at least one adhesive pad can be applied by the transfer roller to the end of the first and/or second material web is. Alternatively or additionally, it is provided that the support surface of the cutting device is designed to be movable in the direction of the transfer roller. The material web is moved by the movement in the direction of the transfer roller, so that the at least one adhesive pad can be applied to the end of the first and/or second material web. The cutting device may include first and second support surfaces. Provision is also made for the first or the second support surface to be designed to be movable in the direction of the transfer roller. In this way, the at least one adhesive pad can be applied in a targeted manner to the end of the first or the second web of material. Of course, both support surfaces can also be designed to be movable, as described above.

Since the material web is at rest during this process, the adhesive application device can also be set up in particular to carry out a rolling movement when the transfer roller comes into contact with the material web. During this rolling movement, the transfer roller is rolled on the surface of the material web until the at least one adhesive pad has been completely transferred to the material web.

The adhesive application device, which is set up to apply the adhesive pad from an adhesive transfer tape, can also be set up to carry out the described radial displacement movement and/or the rolling movement. Such an adhesive application device can also be designed to be movable between a rest position and an application position. The adhesive application device can also include cassettes in which the transfer adhesive tape is located. These cassettes are attached to a bracket with quick-release fasteners, for example, so that they can be easily replaced. An adhesive application device, in which the adhesive pad is applied by an adhesive transfer tape, can alternatively or additionally be combined with a cutting device, the support surface of which points in the direction of the adhesive application device is designed to be movable. The above statements apply analogously, with the difference that the support surface is designed to be movable in the direction of the adhesive application device, in particular in the direction of the at least one cassette, instead of in the direction of the transfer roller.

The device also includes, in particular, a press which is provided downstream of the adhesive application device as part of the connecting device. Such a pressing device comprises, for example, two counter-rotating press rollers, between which the endless web of material runs. In order to improve the adhesion between the adhesive pad and the material webs in the overlapping area, the pressing device can be set up to exert a contact pressure on the endless material web at least in the overlapping area.

1. a) eine durch die Schneidvorrichtung bestimmte Form des Schnitts der freien Enden,
2. b) eine durch die Verbindungsvorrichtung bestimmte Abmessung des Überlappungsbereichs in Förderrichtung,
3. c) eine Masse des zumindest einen von der Klebstoffapplikationseinrichtung aufbringbaren Klebepads,

derart aufeinander abgestimmt sind, dass ein Wert eines über die Breite der endlosen Materialbahn im Überlappungsbereich gebildeten Linienintegrals der Masse und/oder des Volumens um weniger als 10 %, insbesondere um weniger als 5 %, ferner insbesondere um weniger als 3 % vom Wert eines entsprechenden entlang einer parallelen Linie außerhalb des Überlappungsbereichs berechneten Linienintegrals abweicht.According to a further advantageous embodiment, the device is developed in that at least two of the following three parameters:

1. a) a shape of the cut of the free ends determined by the cutting device,
2. b) a dimension of the overlapping area in the conveying direction determined by the connecting device,
3. c) a mass of the at least one adhesive pad that can be applied by the adhesive application device,

are matched to one another in such a way that a value of a line integral of the mass and/or volume formed across the width of the endless web of material in the overlapping area is less than 10%, in particular less than 5%, further in particular less than 3% of the value of a corresponding line integral calculated along a parallel line outside the overlap area.

By coordinating at least two, in particular all three of the parameters mentioned under a) to c), the increase in mass in the overlapping area, viewed along a line integral, can be avoided or at least almost avoided.

According to some embodiments, viewed along the line of the line integral, the material-free areas will be larger than the overlap zones. An overlapping zone is understood to mean an area that lies in the overlapping area of the flat webs and in which the flat webs lie on top of one another. In the overlapping zone, the endless flat web has a multiple material thickness, or twice the material thickness in the case of two material webs of the same thickness. The material-free areas serve to compensate for the excess mass in the overlapping zones and the mass of the applied adhesive pad. The dimensions of the material-free areas and the overlapping zones can be determined, for example, by the shape of the cut of the cutting device (measure a)).

If the overlapping area increases in the conveying direction, the overlapping zones will also increase and the increase in mass in the overlapping area, again viewed along the line integral, will also increase (measure b)). This effect can be compensated for, for example, by appropriate designs of the cut (measures a)), which then provides relatively large material-free areas. In this way, coordination between the shape of the cut and the dimension of the overlapping area in the conveying direction is conceivable. One or both parameters can now in turn be matched to the mass of the applied adhesive pads (measure c)). Depending on the size or mass of the adhesive pads, the cut, i.e. the shape and size of the material-free areas and the overlapping zones, can be adjusted and the overlapping area can be increased or decreased in the conveying direction. This measure would correspond to an exemplary coordination of all three parameters.

According to a further embodiment, the cutting device is set up in particular to cut the free ends of the two material webs in an inversely complementary manner. For example, the shape of the section sinusoidal. The sinusoidal cut made in the first web of material is 180° out of phase with the sinusoidal cut made in the second web of material. Wave crest meets wave crest and wave trough meets wave trough. The two webs of material overlap in the area of their wave crests and form overlapping zones there. In the area of the wave troughs, there are openings in the endless web of material, ie material-free areas.

If the cut of the cutting device is sinusoidal, it is advisable to make the adhesive pads round or oval. In this way, the area present in the overlapping zone, in which the two webs of material lie on top of one another, can be ideally utilized. A particularly strong and stable connection of the two webs of material is possible.

According to a further embodiment, the cutting device is developed in that it comprises a punching tool or a cutting tool which is set up to produce at least one material-free area or opening in the overlapping area of the two material webs. In this way, additional material can be saved in the overlapping area of the two material webs, with the aim of counteracting an increase in mass in the overlapping area.

According to a further embodiment, the device is developed in that the cutting device has a first support surface for contacting the outgoing first web of material and a second support surface for contacting the second web of material, the first and/or the second support surface each having at least one fluid-dynamic gripper for holding the first and/or second web of material are/is equipped.

Non-porous webs of material, such as wrapping paper webs, can be used in the cutter and splicer easily fixed using vacuum grippers. However, this is not possible with porous webs of material due to their permeability to air. For this reason, a fluid dynamic gripper is used.

In the context of the present invention, a fluid dynamic gripper is understood to mean a gripping device that makes use of the physical effect that in a fluid, which can be considered incompressible at first approximation, the flow velocity of a stationary flow decreases with the available flow cross-section increases. The increased flow speed in turn leads to a reduction in pressure in the area in which the smaller cross-section is available for the flow.

A fluid dynamic gripper uses airflow to hold an object, in this case a web of material, without physical contact. It is based on the airflow principle, according to which a high-velocity airflow has a low static pressure. With careful design, the pressure in the high velocity airflow can be less than atmospheric pressure. This results in a net force on the object, i.e. the flat web, in a direction perpendicular to the support surface. A fluid dynamic gripper exploits this by maintaining a low static pressure on a gripper surface, which is at least approximately in the support surface, compared to the ambient pressure, while at the same time there is an air gap between the gripper or support surface and the object being held, i.e. the material web , is maintained.

The fluid dynamic gripper according to the aforementioned exemplary embodiment comprises at least one connection via which compressed air is supplied to the gripper. In each case, this connection leads via a supply channel to a distribution chamber into which the supply channel opens. The distribution chamber has a narrow gap that opens out at a gripping surface of the fluid dynamic gripper. This gap is preferably designed in such a way that the air is at an acute angle to the gripping surface flows out and spreads as parallel as possible to the gripping surface.

Starting from the outflow gap, the compressed air flows between a material to be held, in the present case the first and/or second web of material, and the gripping surface of the fluid-dynamic gripper. In this area, the compressed air flows at high speed due to the small flow cross-section available. As a result, a negative pressure is created in this area between the gripping surface and the web of material. The material web is pressed against the gripping surface of the fluid dynamic gripper by the ambient pressure.

The device is further developed in that the first and the second support surface each comprise only a single fluid-dynamic gripper. If several fluid-dynamic grippers were arranged in the support surfaces, they could impede each other's effect. However, it is also provided that several fluid dynamic grippers are arranged in a single support surface.

According to a further embodiment, the at least one fluid dynamic gripper can be designed in the form of a strip. In the context of the present description, a strip-shaped fluid-dynamic gripper is to be understood as meaning a fluid-dynamic gripper whose distribution chamber is elongated and opens into a narrow outflow gap provided for air outlet, this outflow gap having straight sections opposite one another, which run at least approximately parallel to one another. The straight sections of the outflow gap are connected to one another, for example, by arcuate gap sections. This outflow gap is also designed, for example, in such a way that the air flows out at an acute angle to the gripping surface and spreads out as parallel as possible to the gripping surface. The outflow gap preferably lies in a common plane with the support surface.

Fluid dynamic grippers have proven to be particularly suitable for holding porous, air-permeable materials. According to further embodiments, it is provided that additional gripping devices should be provided, for example in the case of certain materials, that the fluid dynamic grippers develop an insufficient holding force. For example, a surface covered with needles or a mechanical holding device can be provided for fixation.

According to a further embodiment it is provided that the first and the second porous web of material are made of an air-permeable material, in particular a fleece material, and have a permeability to air which is greater than the permeability to air of a wrapping paper web.

The object is also achieved by a method for connecting a first porous material web running out in a conveying direction to a second porous material web, this method comprising the following steps: cutting a free, trailing end of the first material web and a free, leading end of the second Material web with a cutting device, connecting the free end of the first material web to the free end of the second material web to form an endless porous material web with a connecting device, forming an overlapping area extending transversely to the conveying direction over a width of the endless material web, the cutting device cutting two different courses generated in such a way that at the free end of the first web of material there is a first cut that is not complementary to a second cut that is produced at the free end of the second web of material, and the free ends de r material webs are connected in such a way that in the overlapping area across the width of the endless material web there is at least one opening, the method being developed in that the connecting device comprises an adhesive application device, with which for connecting the free ends of the material webs onto the free end of the first web of material and / or the free end of the second Material web at least one carrier material-free adhesive pad is applied and the material webs are connected to one another with the aid of the at least one adhesive pad.

The same or similar advantages apply to the method as have already been mentioned with regard to the device.

The method is further advantageously developed in that the adhesive application device is used to apply the at least one adhesive pad from an adhesive transfer tape.

The adhesive pad can advantageously also be applied in the form of hot glue or a viscous or highly viscous adhesive. For this purpose, in particular, a transfer roller is also used, as has been described above in connection with the device.

1. a) eine durch die Schneidvorrichtung bestimmte Form des Schnitts der freien Enden,
2. b) eine durch die Verbindungsvorrichtung bestimmte Abmessung des Überlappungsbereichs in Förderrichtung,
3. c) eine Masse des zumindest einen von der Klebstoffapplikationseinrichtung aufgebrachten Klebepads,

derart aufeinander abgestimmt werden, dass ein Wert eines über die Breite der endlosen Materialbahn im Überlappungsbereich gebildeten Linienintegrals der Masse und/oder des Volumens um weniger als 10 %, insbesondere um weniger als 5 %, ferner insbesondere um weniger als 3 % vom Wert eines entsprechenden entlang einer parallelen Linie außerhalb des Überlappungsbereichs berechneten Linienintegrals abweicht.The method is further developed in that at least two of the following three parameters:

1. a) a shape of the cut of the free ends determined by the cutting device,
2. b) a dimension of the overlapping area in the conveying direction determined by the connecting device,
3. c) a mass of the at least one adhesive pad applied by the adhesive application device,

be matched to one another in such a way that a value of a line integral of the mass and/or volume formed across the width of the endless web of material in the overlapping area is less than 10%, in particular less than 5%, further in particular less than 3% of the value of a corresponding line integral calculated along a parallel line outside the overlap area.

Furthermore, the method is characterized in particular by the fact that the cutting device has a first support surface on which the outgoing first web of material is in contact at least during the cutting process, and the cutting device also has a second support surface on which the second web of material is in contact at least during the cutting process, wherein the first and/or the second support surface is/are each equipped with at least one fluid-dynamic gripper with which the first and/or the second material web are/is held.

According to a further embodiment it is provided that the first and the second porous web of material are made of an air-permeable material, in particular a fleece material, and have a permeability to air which is greater than the permeability to air of a wrapping paper web.

The device according to aspects of the invention is also set up in particular to carry out the method according to aspects of the invention.

Further features of the invention will be apparent from the description of embodiments of the invention taken together with the claims and the accompanying drawings. Embodiments according to the invention can fulfill individual features or a combination of several features.

Fig. 1

eine schematische Ansicht einer Vorrichtung zum Verbinden einer ersten und zweiten Materialbahn,

Fig. 2

zwei schematisch vereinfachte Draufsichten auf jeweils zwei miteinander zu einer endlosen Materialbahn verbundene Materialbahnen, gemäß dem Stand der Technik,

Fig. 3

eine schematisch vereinfachte Detailansicht einer Draufsicht auf zwei mit Hilfe von Klebepads zu einer endlosen Materialbahn verbundene poröse Materialbahnen,

Fig. 4

eine schematische Querschnittsansicht entlang der Linie IVIV in Fig. 3,

Fig. 5

eine schematisch vereinfachte perspektivische Detailansicht einer Schneidvorrichtung, umfassend einen Splicetisch und einen Splicestempel,

Fig. 6

eine schematisch vereinfachte perspektivische Ansicht eines Splicestempels,

Fig. 7

eine schematisch vereinfachte perspektivische Detailansicht einer Verbindungsvorrichtung mit einer Klebstoffapplikationseinrichtung, welche beispielhaft dazu eingerichtet ist, Klebepads von Transferklebebändern zu applizieren,

Fig. 8a, 8b

schematische Darstellungen einer weiteren Klebstoffapplikationseinrichtung mit einer Übertragungswalze, in einer Applikationsposition (Fig. 8a)) und in einer Aufnahmeposition (Fig. 8b)),

Fig. 9

eine schematisch vereinfachte Schnittansicht eines fluiddynamischen Greifers einer Verbindungsvorrichtung,

Fig. 10a)

eine schematisch vereinfachte Draufsicht eines leistenförmigen fluiddynamischen Greifers einer Verbindungsvorrichtung und

Fig. 10b)

eine schematisch vereinfachte Schnittansicht durch den leistenförmigen fluiddynamischen Greifer entlang der Linie B-B in Fig. 10b).

The invention is described below without restricting the general inventive concept using exemplary embodiments with reference to the drawings, with express reference being made to the drawings with regard to all details according to the invention that are not explained in more detail in the text. Show it:

1

a schematic view of a device for connecting a first and second web of material,

2

two schematic simplified plan views of two each webs of material connected to one another to form an endless web of material, according to the prior art,

3

a schematically simplified detailed view of a top view of two porous webs of material connected by means of adhesive pads to form an endless web of material,

4

a schematic cross-sectional view along the line IVIV in 3 ,

figure 5

a schematically simplified perspective detailed view of a cutting device, comprising a splicing table and a splicing die,

6

a schematically simplified perspective view of a splice die,

7

a schematically simplified perspective detailed view of a connecting device with an adhesive application device, which is set up, for example, to apply adhesive pads of transfer adhesive tapes,

Figures 8a, 8b

Schematic representations of another adhesive application device with a transfer roller, in an application position ( Figure 8a )) and in a recording position ( Figure 8b )),

9

a schematically simplified sectional view of a fluid dynamic gripper of a connecting device,

Fig. 10a)

a schematically simplified plan view of a strip-shaped fluid dynamic gripper of a connecting device and

Fig. 10b)

a schematically simplified sectional view through the strip-shaped fluid dynamic gripper along the line BB in Figure 10b ).

In the context of the invention, features that are marked with "particularly" or "preferably" are to be understood as optional features.

In the drawings, elements and/or parts that are the same or of the same type are provided with the same reference numbers, so that they are not presented again in each case.

1 shows a schematic representation of a device 2 in the tobacco processing industry for connecting a first porous material web 4, which runs out in a conveying direction T, to a second porous material web 6. The material webs 4, 6 and 24 mentioned below are always porous material webs, too unless they are expressly designated as porous. The first web of material 4 is wound onto a first bobbin 8 which is held by a first receptacle 10 . The second web of material 6 is present on a second bobbin 12 which is held on a second receptacle 14 . The two reels 8, 12 each hold a material web 4, 6 of finite length.

The first material web 4 is transported in a conveying plane E with a transport means, not shown, and fed in the conveying direction T for further processing. The device 2 comprises a schematically illustrated cutting device 16 for cutting a free trailing end 18 of the first material web 4 and a free leading end 20 of the second material web 6.

The device 2 also includes a connecting device 22 for connecting the two cut free ends 18, 20 of the first and second web of material 4, 6 of finite length to form an endlessly long web of material 24, forming an area of overlap 26. Endless webs of material joined according to methods known in the art are shown in Figs 2 shown.

The transport means, not shown, can be designed for transporting the material webs 4, 6, 24 together or separately. The material webs 4, 6 of finite length or their drive means can preferably be controlled separately in order to position the free ends 18, 20 to be connected, for example in the area of a support surface 28, one above the other or below one another to form the overlapping area 26 in the conveying direction T, offset from one another. The receptacles 10, 14 for the reels 8, 12 can be pins, mandrels or shafts, which can be designed to be stationary or driven. The material webs 4, 6, 24 can also be guided over deflection and/or guide rollers 30 for deflecting and/or guiding the individual material webs 4, 6, 24. The guide roller 30 shown as an example and further guide rollers that are optionally present and not shown can also be designed as transport rollers.

The device 2 comprises the connecting device 22 which is designed and set up to form the overlapping area 26 and which is provided with at least one opening 32 over the entire width B of the endless web of material 24 . In this way, the overlapping area 26 can be formed with reduced material and an accumulation of material in the overlapping area 26 can be avoided. In contrast to a perforation, in the context of the present description, an opening 32 is always understood to mean an opening that has a surface area of more than 1 mm ² .

2 shows, in a schematically simplified plan view, two endless webs of material 24, which are formed by connecting the free ends 18, 20 of a first and a second web of material 4, 6. The Endless Webs of material 24 are made using conventional devices and methods known in the art. The following explanations are given bearing in mind that the techniques known from the prior art are not suitable for connecting porous webs of material.

A trailing free end 18 of the first material web 4 overlaps the second material web 6 in the overlapping region 26 up to a limit predetermined by the leading free end 20 thereof. This applies to both the in 2 left as well as for the in 2 Endless material web 24 shown on the right. The free ends 18, 20 of the material webs 4, 6 are cut in a complementary manner, which means that the free ends 18, 20 when connecting the material webs 4, 6 over the entire width B of the endless material web 24 form a closed overlapping area 26 . As a result, an accumulation of material occurs in the overlapping area 26 . Because the cuts made at the free ends 18, 20 are not perpendicular to the conveying direction, as is the case for the left-hand strip of material 24 in 2 shown, but guided at an acute angle, as well as in 2 shown on the right, the accumulation of material can be stretched over a larger area in the conveying direction T. Accordingly, the overlapping area 26 in the 2 Material strips 24 shown on the right larger. However, material accumulation or thickening still occurs in the overlapping area 26 .

However, the cutting device 16 according to the invention for cutting the free ends 18, 20 of the material webs 4, 6 is designed in such a way that accumulations of material in the overlapping area 26 can be compensated for.

3 shows a detail of the first web of material 4 and the second web of material 6, which overlap one another in an overlapping region 26, in a schematically simplified plan view. As already mentioned, the Overlap area 26 to compensate for material accumulations that otherwise occur in this area has at least one opening 32 . The side edges of the overlapping area 26 can, as in 3 shown, be open or closed. The number of openings 32 and overlapping zones 34 can vary as desired. The cut edges, ie the cuts at the trailing free end 18 of the first material web 4 and at the leading free end 20 of the second material web 6, can be of any shape. A sinusoidal course of the cut edges is shown as an example. The sinusoidal progression of the cuts is phase-shifted by 180°. In this context, it is crucial that there are cuts that are not complementary to one another. In this context, non-complementary means that the cut flat webs do not complement each other to form a closed surface when they are pushed against one another in one plane with their cut edges. This is the only way to create overlapping zones 34 and openings 32 . Adhesive pads 40 are located in the overlapping zones 34 to connect the free ends 18, 20 of the material webs 4, 6.

The adhesive pads 40 used are adhesive pads 40 without carrier material. Unlike, for example, a double-sided adhesive tape, they do not include any carrier material. They consist only of the adhesive itself.

The connecting device 22 can also be equipped with an in 1 not shown pressing device for connecting the free ends 18, 20 of the material webs 4, 6 may be provided. A pair of rollers, for example, is suitable for this purpose, which presses the material webs 4, 6 together from below and above, in particular in the overlapping area 26. A reliable connection of the material webs 4, 6 in the overlapping zones 34, mediated by the adhesive pads 40, can thus be achieved.

The cutting device 16 can also have a cutting or punching device, with which, in addition to the in 3 shown breakthroughs 32 further breakthroughs in the two material webs 4, 6 are introduced. In this way, the material present in the overlapping area can be further reduced in order to avoid an accumulation of material.

4 shows a cross section along the plane IV-IV in 3 . The adhesive pad 40 is preferably applied to the second web of material 6 and this is then connected to the trailing free end 18 of the first web of material 4 . Conversely, however, it is also possible to apply the adhesive pad 40 to the first material web 4 or even to apply adhesive pads 40 to both material webs 4 , 6 .

figure 5 shows the cutting device 22 in a schematic perspective view, which comprises a splicing die 42 and a splicing table 44 . The splicing die 42 and the splicing table 44 have cooperating, wavy-shaped knives 38 to produce the cutting edges shaped as desired. By the splicing table 44 being moved in the direction of the splicing stamp 42 and the two parts of the blade 38 interacting or engaging, a material web 4, 6 resting on the support surface 28 is cut. The splicing die 42 of the cutting device 16 comprises a first support surface 28a for contacting the outgoing first web of material 4 and a second support surface 28b for contacting the second web of material 6. The support surfaces are denoted jointly by reference numerals 28. Both support surfaces 28a, 28b are each equipped with a fluid dynamic gripper 46 for holding the first and second material web 4, 6, respectively. The fluid dynamic gripper 46 and its mode of operation are described in detail in connection with 9 explained.

6 shows a further perspective view of the splicing die 42. The outgoing first web of material 4 and the incoming second web of material 6 are indicated. The fluid dynamic grippers 46 in the support surfaces 28a, 28b are also shown.

7 shows a further perspective view of an adhesive application unit 48 which is set up, for example, to apply three adhesive pads 40 each from an adhesive transfer tape to the second material web 6 . The adhesive application device 48 includes, for example, three adhesive dispensers 49, in each of which the adhesive transfer tape is accommodated. If the adhesive transfer tape has been used up, the entire adhesive dispenser 49, of which only one is provided with reference numbers for reasons of clarity, can be exchanged and refilled. The adhesive application device 48 is also set up, as indicated by a double arrow, to be moved out in a travel direction 54 in order to apply the adhesive pads 40 . Otherwise, the adhesive application device 48 is located, for example, behind a rear wall 60 and is advanced through a corresponding opening. The adhesive dispensers 49 are located on a corresponding support arm 51, which can be moved in the travel direction 54 indicated by the double arrow. To apply the adhesive pads 40, the adhesive rollers 49 are moved according to a rolling movement in the direction indicated by the arrow 50.

Figures 8a and 8b schematically show different states of an alternative adhesive application device 48. This comprises a transfer roller 52, by which the adhesive pads 40 can be applied to the upper side of the second material web 6, for example. Below the support surface 28 is indicated schematically. The transfer roller 52, like the carrier arm 51, can be moved in a direction of travel 54. Figure 8a shows the application of the adhesive pads 40 to the material web 6. The transfer roller 52 is in the application position. Figure 8b shows the application of the adhesive pads 40 to the transfer roller 52, which is in the pick-up position. The direction of travel 54 is oriented at least approximately parallel to an axial direction of the transfer roller.

Applying the adhesive pads 40 to the transfer roller 52 may vary from the embodiment in FIG 7 , in which several (example three) adhesive dispensers 49 are used, only a single adhesive dispenser 49 is used. If a single adhesive dispenser 49 is used, multiple adhesive pads 40 can be applied to different positions of the transfer roller 52 by multiple unrolling movements and stepwise movement of the transfer roller 52 in the direction of travel 54 . If several adhesive rollers 49 are present, the adhesive pads 40 are transferred from the adhesive rollers 49 to the transfer roller 52 at the same time. Subsequently, the transfer roller 52 is extended through an opening 56 in the rear wall 60 for the application of the adhesive pads 40 .

In the event that only a single adhesive dispenser 49 is used, the transfer roller 52 is preferably designed in such a way that it is made up of several partial rollers (e.g. three partial rollers if three adhesive pads 40 are to be applied), the partial rollers being optionally freely rotatable and blockable and are mounted on a common axis. Depending on the number of adhesive pads 40 to be transferred, a corresponding number of partial rollers is provided. If several adhesive dispensers 49 are used, a single transfer roller 52 is sufficient.

As an alternative to applying adhesive pads 40, an adhesive, for example hot glue or another viscous to highly viscous glue or adhesive, can also be applied to the transfer roller 52. This forms adhesive pads 40 on the transfer roller 52, which are then applied.

The support surface 28 of the cutting device 16 can be designed to be movable in the direction of the transfer roller 52 or in the direction of the adhesive dispenser 49 . The material web 4, 6 is moved by this movement in the direction of the transfer roller 52 or the adhesive dispenser 49, so that the at least one adhesive pad 40 can be applied to the end 18, 20 of the first and/or second material web 4, 6.

9 shows a sectional view through a fluid dynamic gripper 46, which is preferably round in plan view (cf., for example, figure 5 and 6 ). This has two connections 58, 59 through which it can be supplied with compressed air. Starting from the connections 58, 59, the air flow passes through a supply channel 63 into a distribution chamber 61 and leaves the distribution chamber 61, as indicated by arrows, through an outflow gap 62. The outflow gap 62 is, for example, circular when viewed in a plane of the support surface 28. The compressed air supplied via the connections 58, 59 leaves the outflow gap 62 at high speed and flows from there, as also indicated by arrows, between a material web 4, 6 and a support surface 28 of the splicing table. Due to the high flow speed of the air in the narrow cross section between the web of material 4, 6 and the supporting surface 28, the ambient pressure that otherwise prevails in this area is reduced. As a result, the ambient pressure exerts a pressing force F on the material web 4, 6, as indicated by the arrows pointing vertically upwards. This pressing force F holds the material web 4, 6 at the desired location. With the aid of the fluid dynamic gripper 46 shown, it is also possible to fix material webs 4, 6 at the desired location, which are at least partially permeable to air. This is not possible with conventional vacuum grippers. For this reason, the use of the fluid dynamic gripper 46 for the processing of porous material webs 4, 6 is particularly advantageous.

Figure 10a ) shows a schematically simplified plan view of a strip-shaped fluid dynamic gripper 46, as can be integrated, for example, in a support surface 28 of a connecting device 22. Figure 10b ) shows a schematically simplified sectional view through this strip-shaped fluid dynamic gripper 46 along the line BB in Figure 10a ). As already in connection with 9 explained, this also has a connection 58 through which the gripper 46 can be supplied with compressed air. The air flow arrives from the connection 58 through the supply channel 63 into the distribution chamber 61, and leaves the distribution chamber 61 through an outflow gap 62. The outflow gap 62 is delimited by a central body 64 and the main body 66 surrounding it.

The strip-shaped fluid-dynamic gripper 46 is designed in such a way that the outflow gap 62 has straight sections 68 lying opposite one another and running at least approximately parallel to one another. The straight sections 68 of the outflow gap 62 are connected to one another, for example, by arcuate gap sections 70 .

Due to the elongated configuration of the outflow gap 62 , the air essentially flows out at the straight sections 68 . The exiting air flow is given a preferred direction in this way; it no longer spreads out from the gripper 46 in the entire plane of the support surface 28, but preferably in directions perpendicular to the straight sections 68. By appropriately arranging the fluid-dynamic grippers 46, this can be prevented be that in an embodiment in which more than one fluid dynamic gripper 46 is provided per support surface 28, the air flows of the gripper 46 impede each other and consequently the gripper 46 impair each other in their effect. For example, several strip-shaped fluid dynamic grippers 46 could be arranged in a row next to one another.

All of the features mentioned, including those that can be taken from the drawings alone and also individual features that are disclosed in combination with other features, are considered essential to the invention alone and in combination. Embodiments according to the invention can be fulfilled by individual features or a combination of several features.

Reference List

2

contraption

4

first porous web of material

6

second porous web of material

8th

first bobbin

10

first shot

12

second bobbin

14

second shot

16

cutting device

18

trailing free end of the first web of material

20

leading free end of the second web of material

22

connecting device

24

endless web of material

26

overlap area

28

support surface

28a

first support surface

28b

second support surface

30

guide rollers

32

breakthrough

34

overlap zone

36

cutting edge

38

knife

40

adhesive pads

42

splice stamp

44

splicing table

46

fluid dynamic gripper

48

Adhesive Application Device

49

glue dispenser

50

direction of rolling motion

51

carrier arm

52

transfer roller

54

travel direction

56

opening

58, 59

connections

60

back panel

61

distribution chamber

62

outflow gap

63

feed channel

64

central body

66

main body

68

straight sections

70

arcuate sections

T

conveying direction

E

funding level

B

Broad

f

pressure force

Claims (10)

Device (2) in the tobacco processing industry for connecting a first porous material web (4) running out in a conveying direction (T) to a second porous material web (6), comprising a cutting device (16) for cutting a free, trailing end (18) the first web of material (4) and a free, leading end (20) of the second web of material (6) and a connecting device (22) for connecting the free end (18) of the first web of material (4) to the free end (20) of the second Material web (6) into an endless material web (24) with the formation of an overlapping region (26) extending transversely to the conveying direction (T) over a width (B) of the endless material web (24), the cutting device (16) also being set up for this to produce two different cutting paths, such that at the free end (18) of the first web of material (4) there is a first cutting path which is not complementary to one at the free end (20) of the second Material web (6) generated second cutting course and wherein the connecting device (22) is set up to connect the free ends (18, 20) of the material webs in such a way that in the overlapping area (26) across the width (B) of the endless material web (24) there is at least one opening (32 ) is present, characterized in that the connecting device (22) comprises an adhesive application device which is set up to connect the free ends (18, 20) of the material webs (4, 6) to the free end (18) of the first material web (4 ) and/or the free end (20) of the second material web (6) to apply at least one adhesive pad (40) without carrier material. Device (2) according to Claim 1, characterized in that the adhesive application device (48) is set up to apply the adhesive pad (40) from an adhesive transfer tape. Device (2) according to claim 1 or 2, characterized in that at least two of the following three parameters: a) a shape of the cut of the free ends (18, 20) determined by the cutting device (16), b) a dimension of the overlapping area (26) in the conveying direction T determined by the connecting device (22), c) a mass of the at least one adhesive pad (40) that can be applied by the adhesive application device (48),
are matched to one another in such a way that a value of a line integral of the mass and/or volume formed across the width (B) of the endless web of material (24) in the overlapping area (26) is less than 10%, in particular less than 5%, further in particular differs by less than 3% from the value of a corresponding line integral calculated along a parallel line outside the overlap region (26). Device (2) according to any one of claims 1 to 3, characterized in that the cutting device (16) has a first support surface (28a) for the system of the outgoing first material web (4) and a second support surface (28b) for contacting the second web of material (6), the first and/or the second support surface (28) each having at least one fluid dynamic gripper (46) for holding the first and/or second web of material (4, 6) are/is equipped. Device (2) according to one of Claims 1 to 4, characterized in that the first and the second porous material web (4, 6) are made of an air-permeable material, in particular a fleece material, and have a permeability to air which is greater than that Permeability to air of a wrapping paper web. Method for connecting a first porous material web (4) running out in a conveying direction (T) to a second porous material web (6), comprising the following steps: Cutting a free, trailing end (18) of the first material web (4) and a free, leading end (20) of the second material web (6) with a cutting device (16), Connecting the free end (18) of the first material web (4) to the free end (20) of the second material web (6) to form an endless porous material web (24) with a connecting device (22), forming a transverse to the conveying direction (T ) Over a width (B) of the endless material web (24) extending overlapping area (26), wherein the cutting device (16) produces two different cutting paths such that a first cutting path is present at the free end (18) of the first web of material (4) which is not complementary to a second cutting path produced at the free end (20) of the second web of material (6). is and the free ends (18, 20) of the material webs (4, 6) being connected in such a way that there is at least one opening (32) in the overlapping area (26) over the width (B) of the endless material web (24), characterized in that the connecting device (22) comprises an adhesive application device (48) for connecting the free ends (18, 20) of the material webs (4, 6) to the free end (18) of the first material web (4) and/or the free end (20) at least one adhesive pad (40) without carrier material is applied to the second material web (6) and the material webs (4, 6) are connected to one another with the aid of the at least one adhesive pad (40). Method according to Claim 6, characterized in that the adhesive application device (48) is used to apply the at least one adhesive pad (40) from an adhesive transfer tape. Method according to claim 6 or 7, characterized in that at least two of the following three parameters: a) a shape of the cut of the free ends (18, 20) determined by the cutting device (16), b) a dimension of the overlapping area (26) in the conveying direction (T) determined by the connecting device (22), c) a mass of the at least one adhesive pad (40) applied by the adhesive application device (48),
are matched to one another in such a way that a value of a line integral of the mass and/or volume formed across the width (B) of the endless material web (24) in the overlapping area (26) is less than 10%, in particular less than 5%, further in particular differs by less than 3% from the value of a corresponding line integral calculated along a parallel line outside the overlap region (26). Method according to one of Claims 6 to 8, characterized in that the cutting device (16) has a first support surface (28a) against which the outgoing first material web (4) rests at least during the cutting process, and the cutting device (16) also has a second Support surface (28b) on which the second Material web (6) is in contact at least during the cutting process, with the first and/or the second support surface (28a, 28b) each being equipped with at least one fluid dynamic gripper (46) with which the first and/or the second material web (4, 6th ) are/is being held. Method according to one of Claims 6 to 9, characterized in that the first and the second porous material web (4, 6) are made of an air-permeable material, in particular a fleece material, and have a permeability for air which is greater than the permeability for air a wrapping paper web.

Images