DE20121347U1 - Device for producing a plurality of layers of absorbent - Google Patents

Description

&Kgr;&Rgr;00022 03.05.2002

Device for producing a plurality of absorbent layers

The present invention relates to a device for producing an absorbent layer by means of at least one absorbent layer, wherein the absorbent layer is produced continuously. The device has at least a first feed, a second feed and an absorbent feed. A first layer is fed by means of the first feed and a second layer is fed by means of the second feed in order to arrange at least one absorbent layer between them.

EP 0 429 393 A2 discloses a method in which absorbent pads for absorbing body fluids in hygiene articles are produced. According to the method described therein, absorbent pads of any shape can be produced continuously without time-consuming layering of partial layers, with excess material being sucked off and returned when the profile is created. The absorbent pads produced in this way can be separated from one another thanks to a separating edge. EP 0 860 158 A1 discloses a process for producing an absorbent layer that has an absorbent layer. A second layer, preferably made of the same material, is superimposed on a first layer, preferably made of airlaid material, with absorbent being arranged between these two layers. The first and second layers are continuously brought together. This absorbent layer is then cut, with the cut edges of the first and second layers being spread apart from one another in order to apply an adhesive as a binding agent to these end surfaces.

Based on this prior art, it is the object of the present invention to provide a device to facilitate an automated manufacturing process and at the same time to minimize the time required to produce a finished product as well as the materials to be used.

This object is achieved with a device for the continuous production of an absorbent layer with the features of claim 9, with a device with the

Features according to claim 10 as well as a device with the features of claim 11. Furthermore, an absorbent layer with the features of claim 14 is created.

A device according to the invention for producing an absorbent layer with at least one absorbent layer provides that the absorbent layer is produced continuously. A first layer is fed to a second layer so that the first and second layers surround at least one absorbent layer. A binding agent is arranged transversely to a direction of movement of the first layer at least in strip form in order to be positioned between separately arranged absorbent layers to produce a transverse seal of the absorbent layer.

A further development of the device provides that before the binding agent is applied, part of the absorbent layer is removed from the first layer. The binding agent can then be arranged, in particular applied, to a section of the first layer that has been cleared in this way without disturbing binding agent particles. This makes it easier to connect, preferably stick, the first layer to the second layer. In addition, microcracks in the seal formed by this type of connection are avoided when tensile and/or shear forces act on a later product made from the absorbent layer. Tearing or opening of the essentially sealed product is prevented. Preferably, a transverse seal of the absorbent layer is created using the binding agent. In addition, it is possible to create a longitudinal seal of the absorbent layer continuously in addition to the transverse seal. According to a further development, it is also possible for transverse sealing and longitudinal sealing to be created using one and the same binding agent, for example by applying it to the entire surface of the first layer. According to a further embodiment, a first dosing unit is provided for a transverse seal and a second dosing unit is provided for a longitudinal seal of the suction layer. This allows different binding agents and amounts to be used for the respective seal.

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According to a further development, the binding agent is supplied discontinuously, at least partially, preferably only in defined areas. This means, for example, that the binding agent is only present in a certain section of the first layer. This section can form a transverse seal or a longitudinal seal. It is also possible for one or more absorbent layers to be at least partially coated or interspersed with binding agent. For this purpose, the binding agent can be arranged, for example, between different absorbent layers arranged one above the other.

According to a further embodiment of the invention, at least part of the seal is produced mechanically, with the binding agent forming a mechanically acting connection between the first and second layers. Mechanical bonding is possible by means of carding, embossing, folding or in another way, with the material of the first layer being hooked into or onto the material of the second layer, for example. One embodiment of the invention provides for a calender with at least a first and a second roller. The first roller is, for example, a smooth roller. The second roller is a counter roller provided with a surface contour, in particular an engraved roller. Due to the surface contour, the first and second layers are connected to one another at least in partial areas according to the contour. Preferably, a complete sealing of at least one absorbent layer takes place. The geometry of the seal can be determined by selecting the surface contour. A further development provides for the use of two rollers, both of which have a structure, in particular such that one roller partially engages the other. This enables the formation of, for example, three-dimensional seals.

A further development provides that the first and/or the second layer contain at least parts that cause adhesion under pressure and/or heat. These can be, for example, adhesive fibers that are included in at least one layer. It is also possible that at least one of the layers to be connected to one another contains bicomponent fibers that enable surface bonding. According to a further embodiment, a thin adhesive film is placed between the first and the second layer. The adhesive film connects the two layers.

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with each other. The adhesive film can be fed in wide strips, lengthways or crossways, to enable longitudinal or crosswise sealing. If the first and second layers are fed through a calender, for example, sealing takes place according to the surface contour and the arrangement of the adhesive.
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A further embodiment provides that an adhesive is at least partially applied to the second layer, which is then fed to the first layer carrying the absorbent layer. This enables in particular the use of a binder application device which is in contact with the layer and which arranges at least one strip of binder on the layer. According to another embodiment, for example, a transverse and/or a longitudinal strip of binder is applied to the first layer and then at least one absorbent layer is applied, preferably in the binder-free area of the layer.

The binding agent can be used wet or dry, in particular applied to a layer. A binding agent can also be applied in this way, for example, using rotary printing or screen printing. In addition to a closed strip of binding agent, it is also possible to use binding agent dots, binding agent lines or other geometries. The binding agent can also be applied using a spraying process, for example spiral spraying. Another embodiment provides for the use of a fiber spraying device. This can be used to position adhesive fibers between the first and second layers in order to create a seal. In particular, so-called "hot melt" can be used for sealing, which has a higher viscosity when heated than at room temperature and can therefore be applied in particular via nozzles. For example, a rubber-based "hot melt" can be used.

According to a further embodiment, a melt film can be used as a binding agent. The melt film is preferably at least vapor-permeable, in particular liquid-permeable. For this purpose, the melt film can be perforated, for example in a suitable mechanical or chemical manner. It is also possible to use a

Fusible fleece should be used. Fusible fleece and fusible foil combine the first and second layers at the desired locations under pressure or heat.

Preferably, an adhesive application for sealing of about 1 to 7 g/m ² , in particular about 3 to 4 g/m ² , is used. The absorbent used can be between about 30 g/m ² and about 500 g/m ² , preferably between about 50 g/m ² and about 300 g/m ² .

An additional embodiment provides that, in addition to mechanical sealing, sealing by means of another binding agent is also provided for in an absorbent layer. For example, transverse sealing can be carried out mechanically, and longitudinal sealing can be carried out by applying an adhesive.

By arranging the binding agent in strips, preferably applying them in strips across the direction of movement, it is possible to seal them later in a subsequent work step without having to cut the absorbent layer open again. Rather, the absorbent layer produced in this way can be produced continuously and divided up accordingly. Absorbent layers that are separated from one another can, for example, be sealed and passed on to a subsequent processing step. For example, the absorbent layer can be wound up or stored, as is clear in particular from WO98/57877, WO98/58864, WO99/59907 and WOOO/53513. Reference is made to the content of these documents with regard to deposition and solidification as well as with regard to further processing and the boundary conditions and options to be observed. Another method for depositing the material is shown in WO98/18706, to which reference is also made here with regard to the type and method of deposition and the parameters to be observed.

When laying down the absorbent layer, it is best to ensure that folds only occur in areas where no absorbent layer is arranged. For this purpose, an absorbent layer can be detected, for example by means of a CCD camera, a capacitance measurement or by means of a marking that is mechanically

or is fed to the suction layer in another way. A signal is fed to the depositing device via a corresponding sensor device, for example, which causes the suction layer to fold by reversing the direction of the deposit. When storing the suction layer on a roll, it is preferable to work with different tensile forces acting on the suction layer. The tensile forces vary and depend in particular on the winding speed and the respective loading state of the winding drum. The aim is to avoid a roll that is too loose.

A further embodiment of the device provides that the first and second layers are only cut after the absorbent layer has been completely sealed. This has the advantage that no absorbent material can escape and ready-made absorbent pads that can be further processed can be continuously produced from the absorbent layer in accordance with predefined parameters. Furthermore, a prior complete sealing enables, for example, the absorbent layer to be produced in-line with subsequent further processing into a finished product. On the other hand, it is also possible to store the absorbent layer accordingly after production and to make it into the required dimensions at a further processing location. For this purpose, the absorbent layer advantageously has corresponding marking means, such as coloring, metallic inserts or overlays or similar detectable means that can be actively or passively detected via a corresponding detection device on the further processing device, for example for position detection.

The device described above enables, on the one hand, the storage of the absorbent layers that have not yet been separated from one another but are already sealed. On the other hand, it enables completely sealed and spaced-apart absorbent layers to be stored together and then fed to further processing in which the sealed absorbent layers are at least partially or completely separated from one another.

A further embodiment of the invention provides that the individual, separate and sealed absorbent layers are deposited and individual absorbent layers are sent for further processing. For example, the individual absorbent layers are transported together, but are already separated from one another in their transport packaging. It is possible to store the individual absorbent layers in magazines, preferably stack them, so that they can be used in a further processing system directly from the magazines.

Another possibility for producing the absorbent layers is to arrange not just one but several absorbent layers on top of each other. These can be made of the same material or different. The latter allows, for example, targeted liquid transport within the absorbent layers to be achieved by selecting the absorbent used and its behavior. Several absorbent layers can also be placed on top of each other and separated from each other, for example by another layer, an adhesive film or something similar.

On the other hand, it is possible for adjacent layers of absorbent material to be arranged offset from one another in the transverse direction. This alternating arrangement allows, for example, absorbent layers of different lengths to be produced next to one another. It is also possible for application devices for binding agents or the absorbent material itself, as well as a suction device for excess binding agent, to work more precisely, since adjacent contours are less disturbed during processing.

According to another embodiment, an absorbent layer can also be formed by several strips that lie next to each other and are not separated from each other. This makes it possible, for example, for one or more absorbent layers to be folded over each other to form an absorbent pad. A seal preferably forms a folding plane.

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The invention further provides a device for continuously producing an absorbent layer. The device has at least a first feed, a second feed and a suction agent feed. A first layer can be fed by means of the first feed and a second layer can be fed by means of the second feed in order to arrange at least one absorbent layer between them. A suction device is arranged on the device in order to suck suction agent from the first layer at defined points in order to create interruptions along a suction agent path.

According to a further independent device for the continuous production of an absorbent layer with at least a first feed, a second feed and an absorbent agent feed, at least one web can be applied transversely to a direction of movement on the first layer in order to form a boundary surface for absorbent to be applied, wherein the web is designed such that an area on the first layer is kept free in order to be part of a transverse seal of an absorbent layer.
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Another device for continuously producing an absorbent layer, proposed independently of this, has at least a first feed, a second feed and a suction agent feed. A first layer can be fed by means of the first feed and a second layer can be fed by means of the second feed in order to arrange at least one absorbent layer between them. A binding agent device is arranged downstream of the suction agent feed, wherein a binding agent can be applied to the material discontinuously from the binding agent device.

The proposed devices can be used individually or integrated together in a system for combining the first layer, the second layer and the at least one absorbent layer, either once or multiple times in series. This integration makes it possible to produce the absorbent layer continuously, with one or more corresponding steps being carried out at the same time, which subsequently lead to sealing of absorbent layers of the absorbent layer. In this way, it is possible to provide different production steps within one system and device. This makes it possible to save costs and time that would otherwise be incurred at these processing stations arranged outside the device.

A further development provides that a depositing device is connected downstream, which for example receives layers of absorbent material that are connected to one another but separated from one another by complete sealing. The depositing device preferably has detection means by means of which sections of the absorbent layer with and without an absorbent layer can be distinguished. This allows depositing to be carried out in a controlled manner depending on the nature of the absorbent layer.

The invention further provides an absorbent layer with at least a first layer, a second layer and an absorbent layer, the absorbent layer being arranged between the first and second layers. A transverse seal of the absorbent layer has a different binding agent than a longitudinal seal. According to a further development of the absorbent layer, the force required to destroy a transverse seal is greater than the force required for a longitudinal seal, or vice versa. For example, a force of at least 20 N/m ² to 25 N/m ² is required to achieve destruction. If thermoplastics are used for sealing, it is advantageous to measure a heat seal strength that is preferably in a range of over 2 N/15mm in a heat seal range of about 50 ^° C to 180 ^° C. In particular, values of over 6 N/15mm, preferably over 9 N/15mm, are aimed for at the maximum before the connection is completely destroyed. The spring test or the Top Wave DTC can be used as a test method, for example.

The absorbent layer preferably has at least one marking means, by means of which, for example, a production line, for example a cut, a fold line, a start and/or end of an absorbent layer, a position indication of the absorbent layer as a reference point for a further processing system and other things can be detected. One or more marking means can be arranged in the absorbent layer, in a seal or in one of the layers.

Furthermore, the invention provides a suction device for a device for the continuous production of an absorbent layer, wherein the suction device is designed such that at least one point for the suction of absorbent material on a

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first position is defined by opening or closing an extraction system of the extraction device.

Further advantageous embodiments and developments are shown in the following drawing. The details described there and the features given for individual devices with regard to production as well as the materials used, parameters, boundary conditions, structures, individual parts and their interaction as well as explanations can generally also be used in other devices and methods of the invention, whether described above or below or not. In particular, these can be combined with the embodiments described above and below to form further advantageous developments. They show:

Figure 1: A continuously rotating belt provided with slots,

Figure 2: the belt shown in Figure 1 installed in a first device for the continuous production of an absorbent layer,

Figure 3: a second device for the continuous production of an absorbent layer,

Figure 4: a third device for the continuous production of an absorbent layer,

Figure 5: a fourth device for producing an absorbent layer, which has a roller,

Figure 6: a fifth device with a roller having depressions on the surface,

Figure 7: a sixth device with a band having recesses,

Figure 8: a seventh device with a hollow roller with variable suction openings,

Figure 9: an eighth device, which includes, for example, a hollow roller as in Figure 8,

Figure 10: a section through a hollow roller, as shown in Figure 8, for example,

Figure 11: a suction channel, such as can be used in a device according to Figure 9,

Figure 12: a schematic view of an example of a suction opening,
Figure 13: a ninth device for producing a suction layer,

Figure 14: a tenth device for producing a suction layer,
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Figure 15: an eleventh device for producing a suction layer and

Figure 16: a schematic plan view of a suction layer with a detection unit.

Fig. 1 shows a belt 1 that rotates around a first roller 2 and a second roller 3. The belt 1 has slots 4. The slots 4 extend transversely to a direction of movement of the belt 1. The belt 1 is preferably made of a plastic material that is reinforced, for example, by means of fiber inserts. The slots 4 contained in the belt 1 pass through the belt 1. According to a further development, material adjacent to the slot 4 in the belt 1 is at least partially reinforced so that no cracks occur when tensions act on the belt 1.

Fig. 2 shows a first device 5 for producing an absorbent layer. The first device 5 has the first roller 2, second roller 3 and belt 1 shown in Fig. 1. The first device 5 also has a third roller 6 and a fourth roller 7. A second belt 8 runs around the third roller 6 and the fourth roller 7. The second belt 8 is preferably a sieve belt, but can also have no openings, but a

have a closed surface 9. A layer is continuously applied to the surface 9 of the second belt 8, to which in turn an absorbent layer 10 is applied. The belt 1 and the second belt 8 preferably move at the same speed, so that the absorbent layer 10 is moved in the direction of the arrow. A suction device 12 can be arranged in the cavity 11 formed by the belt 1 and the first roller 2 and the second roller 3. The suction device 12 is indicated schematically and can be implemented, for example, by means of a box profile arranged in the cavity 11. In the box profile, for example, there is a lower pressure than the ambient pressure. This allows the material of the absorbent layer 10 arranged in the immediate vicinity of the slots 4 to be suctioned off. For this purpose, the second belt 8 is preferably at least partially porous or permeable to air in some other way. According to a further embodiment, an overpressure is at least partially imposed in a second cavity 13, which is formed by the third roller 6, the fourth roller 7 and the second belt 8, so that the material of the absorbent layer 10 to be sucked off also reaches the suction device 12. The suction device 12, however, does not have to be arranged in the first cavity 11. Rather, it can also be present in the second cavity 13. It is also possible for the suction to take place over a larger area, so that the slots 4 traverse a longer path through the suction device 12. This makes it possible to lift the material from the second belt 9 and remove it permanently, preferably with relatively low pressures. According to a further development, which is not explained in more detail here, it is possible to work with at least one pressure gradient within the suction device. For example, when the suction device 12 passes through the slots 4, the pressure will increase or decrease. The pressure decrease or increase can occur suddenly. This can be made possible, for example, by means of a pressure reduction as well as via various pressure connections on the extraction system 12 itself.

Fig. 3 shows a second device 17 for the continuous production of an absorbent layer. The absorbent layer 10 is again continuously deposited on a depositing belt 14, which rotates around a first roller 15 and a second roller 16. The second device 17 has a suction device 18. The suction device 18

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is arranged above the depositing belt 14. It has a roller system 19, via which the extractors 20 are moved. The extractors 20 are connected to one another via a guide system consisting of a first connecting belt 21 and a second connecting belt 22. The respective distance between the extractors 20 is preferably variable. The first and second connecting belts 21, 22 are also designed so that additional extractors 20 can be used. The extractors are guided via the roller system 19 on an upper path 23 opposite to a direction of movement of the depositing belt 14. By deflecting them using the roller system 19, the extractors 20 are guided along a lower path 24 in the same direction as the direction of movement of the depositing belt 14. This results in a lower opening 25 of an extractor 20 slowly being brought closer to the absorbent layer 10. The suction device 20 has, for example, a suction nozzle 26 at an end opposite to the lower opening 25. The suction nozzle 26 is connected to a vacuum unit, which is not shown in detail here. By slowly approaching the lower opening 25 towards the depositing belt 14, material in the immediate vicinity of the lower opening 25 is sucked away. The suction device 18 is preferably arranged such that the lower end 25 extends as far as the depositing belt 14. This ensures that the absorbent layer 10 is completely removed in this area. The extent of the suction of the absorbent layer immediately adjacent to the lower opening 25 can be adjusted using various parameters. These include, for example, the rotational speed of the depositing belt 14 and the roller system 19, an adjustment of the respective speeds (it is also possible to adjust a speed difference between the depositing belt 14 and the suction device 20), the design of the lower opening 25, for example additional suction openings along the length of the suction device 20 that engages at least in the suction layer 10, an air volume flow as well as a volume itself that is suctioned, a gas permeability of the depositing belt 14, a pre-processing of the suction layer 10 (for example, this can be present as a loose powder with different grain diameter consistency, as pre-solidified suction material or, for example, in the form of grains attached to one another, in particular glued grains, preferably as a hardened layer). In the devices shown in Fig. 3 and Fig. 2, preferably

the surfaces that come into direct contact with the absorbent layer 10 are designed in such a way that the absorbent layer 10 does not stick to these surfaces when these surfaces are removed from the absorbent layer 10. This is done, for example, by appropriately selecting the material of the surface, an appropriate surface finish, for example in the form of a coating. In particular, the aim is for the adhesion tendency of this surface to the absorbent layer 10 to be lower than the strength and thus integrity of the absorbent layer 10 at least on its surface, in particular also across the entire material cross-section of the absorbent layer 10.

Fig. 4 shows a third device 27 for producing an absorbent layer. The device 27, like the second device 17 shown in Fig. 3, implements the idea of partial surface contact of a suction with the absorbent layer 10. Preferably, this partial surface contact is limited to a suction device such as in the form of an extractor. Fig. 4 shows an embodiment in which the material of an absorbent layer 10 is moved in the direction of the arrow on a conveyor belt 28. The third device 27 also has a rotating suction device 29. The suction device has a first transport roller 30, a second transport roller 31 and a guide belt 32. Suction nozzles 33 are embedded in the guide belt 32. The suction nozzles 33 are guided around the transport rollers 30, 31 by the guide belt 32. In doing so, they come into contact with the absorbent layer 10. A suction box 35 is arranged in an interior 34. If the suction nozzles 33 come into contact with the suction box 35, the material of the absorbent layer 10 arranged in the area of the suction nozzles 33 is sucked off. The suction box 35 is advantageously designed in such a way that suction stops before the suction nozzles 33 no longer have contact with the absorbent layer 10 or with the conveyor belt 28. This prevents material from being sucked off the side of the absorbent layer 10 or falling back again when the suction nozzles 33 are lifted off by being guided further along the second conveyor roller 31. Preferably, the suction nozzles 33 of Fig. 4, as well as devices engaging or adjacent to the absorbent layer 10 in other technical developments, have a geometry such that an edge region 36 remains largely undamaged. By appropriate design, for example in a conical, in

rounded, convex, conical or other manner, it is possible to obtain a precisely defined edge region 36 within the absorbent layer 10 after suction has taken place.

Fig. 5 shows a fourth device 37 for producing an absorbent layer. The fourth device 37 has a drum 38 instead of a circulating belt in order to achieve suction of material from the absorbent layer 10. The drum 38 is a hollow cylinder, in the outer edge 39 of which inserts 40 are arranged. Instead of the inserts 40, the drum surface can also be provided with holes or correspondingly shaped protuberances. Preferably, some of the inserts 40 protrude from the surface of the drum 38 and can engage in the absorbent layer 10 in this way. A suction device 41 is arranged inside the drum 38. The suction device 41 has a first boundary 42 and a second boundary 43. At a respective end 44 of the boundaries 42, 43, an inner surface 45 of the drum 38 is sealed. The material sucked from the absorbent layer 10 preferably reaches a further processing station via a discharge 46, where the material can be processed and returned to the process. The first limit 42 and the second limit 43 are preferably adjustable, whereby the suction or the extent of the suction can be adjusted. This adjustment option is indicated by arrows. The inserts 40 preferably extend longitudinally parallel to the axis of the drum 38. According to a further development, they have a geometry such that the area of the inserts 40 that first comes into contact with the absorbent layer 10 enables material from the absorbent layer 10 to be cut out. This is particularly advantageous when the absorbent layer 10 already has a certain strength on its surface, for example due to prior hardening such as can be achieved by heating. Furthermore, an outer surface 47 of the drum 38 can be designed in such a way that it has a shaping effect on the surface of the absorbent layer 10. For example, a shape on the surface of the absorbent layer 10 is possible in this way. This shape can be convex, concave, wavy, zigzag or in some other way. This is indicated by a dashed line along a section 48 of the absorbent layer 10. This first section 48 is followed by a second

Section 49 is separated in the transverse direction to the direction of movement of the treadmill 50 carrying the absorbent layer 10. The absorbent layer 10, which is still connected in front of the drum 38, has interruptions 51 due to the suction. These interruptions 51 can be arranged in the longitudinal direction as well as in the transverse direction to the direction of movement of the treadmill 50. The interruptions 51 are preferably designed in such a way that there is no absorbent material on the treadmill 50 in these areas. The treadmill 50 can also be designed to be permeable to air, as in the previous devices. Another possibility is to provide a multi-layer treadmill 50, wherein preferably each of these layers has a different porosity. In particular, the porosity decreases from the layer that comes into direct contact with the absorbent layer 10 to the one furthest away. The treadmill 50 can also be designed in such a way that it has a type of carrier layer that is able to ensure the necessary strength properties for long-term operation. Additional layers on or around this carrier layer can have additional functions: for example, improved absorption of the absorbent layer, good permeability and channeling effect of air flowing through, etc.

Fig. 6 shows a fifth device 52 for producing an absorbent layer. The fifth device 52 has an application drum 53. A surface 54 of the application drum 53 can be smooth, in particular roughened or also have depressions. Absorbent material 56 is fed onto the surface 54 or the depressions via an absorbent layer feed 55. The absorbent material feed can be continuous or discontinuous, for example, so that preferably sections of absorbent material 56 are created that are separate from one another. For example, an application roller 57 of the absorbent layer feed 55 can have subdivisions, so that absorbent material 56 is not only separated in the transverse direction, i.e. parallel to an axis of the application drum 53, but also in the circumferential direction of the application drum 53, for example in the form of gaps. Absorbent material 56 is preferably applied at least in the immediate vicinity of the highest point of the application drum 53. In particular, an application can also be carried out slightly before this point 58. This ensures that the material is evenly applied to the application drum 53.

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Preferably not too far from the application of the absorbent material 56, a first layer 60 is fed to the application drum 53 via a first feed 59 and brought into contact with the absorbent material. Pressure rollers 61 ensure that the absorbent material 56 and the first layer remain in their position. Preferably, a binding agent is applied to the first layer 60 via a binding agent device 62 in such a way that the binding agent lies transversely to a direction of movement of the first layer 60 between separately arranged absorbent layers. Following this, a second layer, which is not shown in detail here, is applied to the first layer 60 and the absorbent material 56. Where a binding agent is present via the binding agent device 62, a transverse seal of the absorbent layer thus created is achieved.

A further development of this fifth device 52 provides that the suction layer feed 55 is followed by a second binding agent device 53. It is also possible for the second binding agent device 63 to be arranged in front of the suction layer feed in the direction of movement of the application drum 53. Furthermore, a layer material 65 is supplied with suction material 56 or a binding agent via a layer feed 64 indicated by dashed lines. The second layer 66 is then fed via the first feed 59, so that a suction layer 67 is continued from the application drum 53. This preferably already has a transverse and longitudinal seal. For example, the second binding agent device 63 can not only be able to supply binding agent discontinuously. Rather, it is also possible for the second binding agent device 63 to allow a continuous supply of binding agent in certain sections. If different binding agents are to be used for transverse sealing and longitudinal sealing, an additional binding agent device, which is not shown in detail here, is provided, for example, upstream or downstream of the second binding agent device 63. This allows separate binding agent feeds, which can be operated at different pressures and temperatures depending on the type of binding agent.

Fig. 7 shows a sixth device 68 for producing an absorbent layer, which uses a band 69. The band 69 can have a roughened surface. Roughening

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results in the suction agent 72 supplied by a suction agent supply device 71 being deposited continuously or, as shown, partially on the belt 69 and being subjected to good adhesion there. Furthermore, the belt 69 can have recesses 70. Suction agent 72 is introduced into these recesses. Excess material can, for example, be guided into the interior of the belt 69. For this purpose, the belt 69 can, for example, be constructed like a mesh grid, so that suction agent 72 can only be deposited on the correspondingly provided surfaces. It is also possible for excess suction agent 72 to be sucked away. A layer feed device 73 is arranged downstream of the suction agent supply device 71. A first layer 74 can be guided onto the belt 69 via the layer feed device 73. Pressure rollers 75 ensure that the absorbent 72 remains in position on the first layer when transferred from a large roll 76 to a subsequent release roller 77. The release roller 77 is, as is preferably the case with all solutions that have direct contact between the absorbent or absorbent layer or the layers, preferably designed in such a way that detachment of a surface of the absorbent in contact with the aforementioned does not lead to destruction of the desired arrangement of the absorbent layer to one or both layers. An adjustment roller 78 is preferably arranged downstream of the release roller 77. The release roller 77 and the adjustment roller 78 can be moved relative to one another in particular so that a release angle 79 can be set. Adequate tension in the band 69 can be ensured by compensating rollers, which are not shown in more detail here. A supply of binding agent, not shown in more detail here, takes place, for example, after the first layer 74 has been detached from the release roller 77.

Fig. 8 shows a preferred solution. A seventh device 80 for producing a suction layer is shown in a schematic view, which device has a hollow roller 81 with variable suction openings 82. The suction opening 82 extends over an angular range 83. This angular range 83 can be adjusted by moving first locking segments 84 and second locking segments 85 mounted in the hollow roller 81. The first locking segments 84 and the second locking segments 85 are each connected to one another, so that an inner cylinder is arranged rotatably in the hollow roller 81. The inner cylinder with locking and suction segments rotates, while the remaining elements are preferably stationary.

The open angle range 83 can be changed by adjusting the first and second blocking segments 84, 85. A connection is established between a discharge line 86 and an intake 87 along the open angle range 83. This can be used to control how much suction medium 88 is sucked out of a first layer 89. The type of suction can also be influenced, for example, by the applied pressure 90, by a length 91 of the discharge line, by a length 92 of the intake 87, by a distance 93 between the suction medium 88 and an intake opening 94 of the intake 87, their geometries and other parameters. The suction behavior is also determined by the geometry of the intake opening 94, by the formation of a possible pulsation, by a design of the conveyor belt 95 for the first layer 89 and by other parameters. The conveyor belt 95 has openings 96, as shown here. It is preferably a sieve belt. The openings 96 facilitate the passage of air through the first layer 89 and thus the suction of the suction medium 88. The device 80 allows the suction to be adjusted. By changing, for example, the rotational speed of the hollow roller 81 depending on the belt speed or the segment setting in the inner cylinder, the device 80 can be adapted to different suction medium lengths, widths and production speeds. The speed of the inner cylinder is determined from a reciprocal value that is formed from the number of segment pairs multiplied by an interval time. The interval time indicates the ratio of a suction medium length added to a length of a suction medium-free point adjoining it in the direction of belt movement in relation to the belt speed.

Fig. 9 shows, by way of example, a larger section of a device 97 for producing an absorbent layer. For example, the seventh device 80 shown in Fig. 8 can be integrated into this device 97. A first layer 99 is fed from a first unwinding station 98 and a second layer 101 is fed from a second unwinding station 100 for further processing. It is also possible to run an in-line process for producing the unwound layers instead of a first and second unwinding station 98, 100. This means that the material of the first and second layers 99, 101 is produced directly before further processing. An absorbent layer 10 is applied to the first layer 99 via an absorbent feed device 102.

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Layer 99 is applied. The suction agent feed device 102 is connected to a mixing unit 103. The mixing unit 103, for example a rotary mixer, is in turn connected to storage containers 104. In the storage containers 104, for example, different materials for the suction agent layer are stored, which are mixed in the mixing unit 103 according to a predeterminable recipe and applied via the suction agent feed device 102 as the suction agent layer 10. For example, superabsorbents, cellulose, binding agents, additives, odorous substances, zeolites, fiber material, alone or in a mixture, can be present in the storage containers 104. Other, usually usable materials can also be stored alone or in a mixture in the storage containers 104. A further advantage of the arrangement of one or more storage containers is that the continuous process can be continued without interruption for refilling with appropriately suitable material by switching the supply line from one storage container to the other. After the absorbent layer 10 has been applied to the first layer 99, these are fed to the seventh device 80. There, the suction material is partially removed from the first layer. In addition to suction, there are also other options, such as mechanically stripping off part of the absorbent layer 10. In order to be able to set a uniform suction pressure during suction, this is regulated, for example. A throttling device, in particular a bypass solution, can be used for this purpose. By means of the bypass solution, in particular a partial air flow is deliberately generated, which is used to facilitate the conveyance of powder to a cyclone 106. It is also possible to design the vacuum generation unit 105, for example a fan, with a speed control. According to one embodiment, the suction material extracted is separated from the suction air flow, for example via a separating device, here represented by the cyclone 106. After appropriate processing, the suction material recovered in this way is returned to the circuit.

After suction material has been sucked off from the suction medium layer 10 according to the embodiment of Fig. 9, the first layer 99 is guided into a heating section 107. Due to the heat transfer occurring there, for example when polymer material is fed into the suction medium 72, the latter is softened, if not completely

to melt. As a result, the grains of the absorbent material stick to one another and form a stable absorbent layer on the first layer 99. Furthermore, corresponding heating also leads to the absorbent layer adhering to the surface of the first layer 99. In a modification of the device 97 not shown in detail here, heating takes place by means of a heating section 107 before the absorbent layer 10 is partially removed from the first layer 99. Preferably, the removal is achieved in particular by means of mechanical action. For this purpose, for example, an appropriately shaped roller or surface, which is guided, for example, by a rotating belt, pierces the absorbent layer 10 and removes it in a desired area. A pre-hardened absorbent layer 10 has the advantage that forces acting on this layer can be greater before an unwanted disturbance of the other areas of the absorbent layer occurs.

A first binding agent device 108 and a second binding agent device 109 are connected downstream of the heating section 107 in Fig. 9. A first binding agent is applied via the first binding agent device 108 in the direction of movement of the first layer 99, which, due to its transverse arrangement, leads to a longitudinal seal between the first and second layers 99, 101 in the further course. For this purpose, the first binding agent is applied in an intermediate space that is preferably free of suction agent. A second binding agent is applied to the first layer 99 via the second binding agent device 109. The second binding agent is applied in such a way that it subsequently leads to a transverse seal in a suction layer 110. The first and second binding agents can be sprayed on, applied by direct contact with an application head or applied to the first layer 99 in another way. Another possibility for applying the second binding agent is to wet the second layer 101 accordingly. For example, this can be done with a roller provided with application surfaces as the third binding agent device 111. According to a further development, the surface of the third binding agent device 111 has elevations which are wetted with a binding agent at a rotational speed synchronized with the movement of the first layer 99. The binding agent is then applied to the surface of the second layer 101. In particular, with this solution,

the possibility that the third binder device 111 is in constant contact with the second layer 101.

After the application of the binding agent(s), the first layer 99 and the second layer 101 are formed into an absorbent layer 110 with the absorbent layer 10 arranged between them via a pressure unit 112, in this case a calender. The calender can be structured on at least one roller surface. The structure has the task, for example, of forming the absorbent layers and/or sealing the absorbent layers. According to the design shown here, the absorbent layer 110 can be stored via a winding device 113. Furthermore, according to a further development, it is possible to guide the absorbent layer 110 directly into a further processing device in which the absorbent layer is divided up, for example, transversely and transversely into individual absorbent packets. The individual absorbent packets, which are not shown in more detail here, are then used in products such as hygiene articles, wipes, oil-absorbent cloths or others.

Fig. 10 shows a schematic longitudinal view through the hollow roller 81 from Fig. 8. The hollow roller 81 has a bearing 114 for its inner hollow core 113, via which a negative pressure is made available for the suction 87. The bearing 114 is arranged, for example, on the first end face 115 and the second end face 116. A connection 117 to the negative pressure generating unit (not shown in detail) is established via a rotating rotary feedthrough 118, for example. The rotary feedthrough 118 is designed to be gas-tight, so that no leakage occurs when the negative pressure is transmitted. So that the same negative pressure is present everywhere over a length 119 of the hollow roller at the same time, the inner hollow core 113 preferably has valve-like fittings, so that a minimum negative pressure is uniform after the suction is opened and the removal of suction material begins. In this way, absorbent layers 10 can be produced which can have any length 120, for example between 45 mm and 181 mm. Longer absorbent layers can be produced without any problems. A distance 121 in the longitudinal direction between absorbent layers can be adjusted continuously. It is preferably between 60 mm and 25 mm. A

Width 122 of the absorbent layers can be adjusted as required and is, for example, between 6 mm and 50 mm. The exact dimensions of the absorbent layers depend on various parameters. The later intended use in the product, the production speed, the materials used and the thickness to be applied all have an influence. Absorbent layers can be arranged continuously, for example, on a width 123 of the first layer of 100 cm or more. The dimensions specified can also be achieved using other devices and methods.

Fig. 11 shows a further embodiment of a suction system, wherein a suction channel 124 is used, which can be used, for example, in a device according to Fig. 9. The suction channel 124, which has, for example, a length 125 between 200 mm and 800 mm, is arranged above a first layer. The suction channel 124 is connected to a vacuum supply line 126. The vacuum line 126 has, for example, a diameter 127. The suction channel 124 in turn has a height 128.

Preferably, the height 128 of the suction channel 124 is greater than the diameter 127 by a factor of 1.5 to preferably 4. The length 125 of the suction channel 124 is in turn preferably longer than the width 129 of the first layer used by a factor of 1.1, in particular by a factor of 1.3 or more. The pressure prevailing in the suction channel 124 or via the vacuum supply line 126 is also controlled by a solenoid valve. This allows rapid opening or closing in a range of less than 0.5 s, in particular in a range between 50 ms and 4

Fig. 12 shows a schematic view of an example of a suction opening 130. In the embodiment shown, a mask 132 is arranged above the absorbent layer 10 and thus above the first layer 131. The mask preferably forms a screen and, with its gap 133, prevents more material from the absorbent layer 10 from being removed than necessary during suction. The mask allows a precise separation between areas to be suctioned and areas not to be suctioned, in particular by preventing incorrect flow due to air flow from the environment. Furthermore, in a further embodiment, the mask 132 allows a certain pressure, for example a negative pressure or a mechanical pressure, to be exerted on the absorbent layer 10. Preferably, the

Gap 133 is slightly smaller than the suction opening 130. In other embodiments, however, the gap 133 can also be larger. The suction opening 130 can in turn be conical in shape, whereby the inner diameter 134 can increase or decrease in the direction of flow. This depends on whether a high or low suction speed is to be achieved directly at the suction medium layer 10.

Fig. 13 shows a further device for producing an absorbent layer. According to this device, a hollow roller 135 is again used. An inner hollow roller 136 is arranged in this hollow roller 135. The inner hollow roller 136 has a suction channel 137, via which suction openings 138 of the hollow roller 135 can be subjected to negative pressure. For this purpose, the hollow roller 135 rotates around the inner hollow roller 136. A first counter roller 139 and a second counter roller 140 are arranged opposite the hollow roller 135. The hollow roller 135, first counter roller 139 and second counter roller 140 are preferably arranged such that the first layer 141, on which an absorbent layer 10 is located, is displaced against the counter rollers 139, 140. This creates a pressure force on the absorbent layer 10. As a result, preferably only material that is also arranged directly opposite a suction opening 138 is removed from the absorbent layer 10. The pressure exerted by the position of the hollow roller 135 in relation to the two counter rollers 139, 140 is adjustable, preferably by shifting the position of at least one of these three rollers. To prevent suction material adhering to a surface of the hollow roller 135 from being carried along with the hollow roller 135, a cleaning device 142 is arranged on the hollow roller 135. This can clean the surface of the hollow roller 135, for example by means of mechanical action, compressed air or other possibilities. The material that falls down in this way is caught and removed via the cleaning device 142. The surface of the hollow roller 135 can also be coated so that the tendency to adhere, particularly to granular materials, is extremely reduced. A binding agent supply device 143 is arranged downstream of the cleaning device 142. This can be used to apply a binding agent to the first layer 141 partially or over the entire surface.

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Fig. 14 shows a further embodiment of a device for producing a suction layer. This device shows by way of example that such a device for producing a suction layer and in particular a partial application of suction agent can also be retrofitted into an existing system. As schematically indicated, the structure of the device is compactly enclosed in a frame. If there is sufficient space within a system, the device can therefore be retrofitted as a module. Suction material 146 is applied to a first layer 147 via a circumferential belt 144 which has openings 145. The belt 144 has webs 148 which are in contact with the first layer 147. The webs 148 partially cover the surface of the first layer 147. The suction material 146 is distributed via the belt 144 to the first layer 147 via a suction material feed 149. The material that comes to rest on the webs 148 is distributed to a desired height by a distribution device 150, for example a brush, a scraper or something else. The belt 144 is then lifted off the first layer 147 and the absorbent layer 10 located thereon at a slight angle of inclination 151. The angle of inclination 151 is preferably between 5° and 35°. The belt 144 is then cleaned of any particles that may be adhering to it by a cleaning device 152. The cleaning device 152 can use suction or ultrasound, for example. In order to catch particles falling off the belt 144, a collecting device 154 is arranged in the area of the deflection 153. Furthermore, the absorbent layer 10 can be compacted in this device as in the previously described ones, for example by exerting pressure using rollers or by exerting pressure via the distribution device 150. Another possibility for compaction is through appropriate vibration compaction. An appropriate vibration can be generated, for example, using ultrasound.

Fig. 15 shows a further embodiment of a device for producing a suction layer. This device can also be retrofitted as a module into an existing system. A suction belt 156 runs around four guide rollers 155. The flexible suction belt 156 is preferably laser-cut and preferably has recesses 157, which preferably run transversely to the direction of travel of the suction belt 156. According to an embodiment not shown here in detail

the suction belt 156 has recesses 157 which are neither perpendicular to the direction of travel nor parallel to it, but rather at an angle to it. It is also possible for the recesses 157 to not only have edges that run parallel to one another, but also curves, i.e. have concave or convex shapes. This does not only apply to recesses in a suction belt 156. Rather, such a geometry can be found mirror-inverted in the absorbent layer 10 on the first layer 158. This means that not only a rectangular cross-section can be achieved with the absorbent layer 10 for different purposes. Rather, such a design also allows geometric shapes such as, for example, a water clock-like longitudinal distribution of absorbent material, conical, convex and other shapes. The suction belt 156 is guided onto the absorbent layer 10. The material of the absorbent layer 10 arranged adjacent to the recesses 157 is removed via a suction device 158. The suction device 158 can be made up of one part or, as shown here, of two or more modules. Furthermore, the suction device 158 can completely cover the suction belt 156 over an entire area. Furthermore, there is the possibility, as shown here, of the suction being carried out in two separate areas. Downstream of the suction device 158 there is a pickup roller 159, designed here as a grooved roller. This interacts with the upstream guide roller 155 of the suction belt 156 located in this intermediate section and the possibility of exerting contact pressure via the suction belt 156 on the first layer and thus also on the absorbent layer 10 arranged in between. The suction belt 156 is lifted off the absorbent layer 10 at a small angle by the pickup roller 159 using a downstream guide roller 155. The suction belt 156 is cleaned, for example, by means of a brush roller 160 shown here. This cleaning device can be supported by further cleaning, for example by means of ultrasound and/or suction. In addition, a vibrating plate 161 is assigned to the guide roller and the brush roller 160. The vibrating plate 161 catches the particles falling from the suction belt 156. On the other hand, with a suitable suspension, it is able to serve as a vibrating plate for the suction material running past on the first layer 162. Arranged downstream of the vibrating plate 161

is a binder supply device 163. The supplied binder 164 is, for example, a binder that only melts at high temperatures.

Fig. 16 shows a schematic view of an absorbent layer 165. The absorbent layer 165 has four absorbent pads 166, the absorbent pads 166 preferably having a structure made up of a first layer 167, an absorbent layer 168 arranged between them and a subsequent second layer 169. The absorbent pads 166 can, however, also have several such structures on top of one another or have several absorbent layers. This is possible, for example, by folding the absorbent layer 165 or by coating it several times. The absorbent pads 166 are also provided with a transverse seal 170 and a longitudinal seal 171. The transverse seal 170 and the longitudinal seal 171 are preferably continuous, i.e. continuous. According to a further development, the transverse seal 170 and the longitudinal seal 171 are individually or jointly partially interrupted at defined points.

Furthermore, a detection unit 172 is shown schematically in Fig. 16. A sensor 173 is able to actively or passively record a signal from the suction layer 165, which can then be evaluated by the detection unit 172. The recorded signal can, for example, provide information about a cutting plane, for example for a cross section, as well as for a longitudinal section through the suction layer to separate the suction pads 166. For this purpose, the suction layer can have markings such as grooves, colored markings or similar. It is also possible to detect an elevation of the suction layer 165, so that it is possible to determine where an absorbent layer 168 is located and in which area it is not. It is also possible to draw conclusions about the distribution of the absorbent layer 168 and subsequently obtain corresponding information by illuminating the suction layer 165 and then comparing light and dark, for example by evaluating images from a CCD camera. According to a further development, the applied binding agent is detected by means of the detection unit. In addition, the above-mentioned detection unit 172 and the various

Detection options are not only applicable for making cuts through the suction layer 165. Rather, it also makes it possible, for example, to check the position of the suction layer 165 during or at the start of further processing, for example when depositing it using a packaging unit in a transport form or a processing plant for producing the end product. As shown, it is also possible to arrange the suction layers not only parallel but also alternately with regard to their cross-sealing. This allows

The invention also makes it possible to package the individual absorbent layers separately in a transport form. The individual absorbent pads can then be specifically incorporated into or on the end product in a further processing station. For example, in the hygiene and incontinence sectors, this makes it possible to position the absorbent pads differently, for example in a diaper, depending on the gender-specific position of the genitals.

The proposed method and the devices are suitable for processing a wide variety of materials. For example, woven materials such as paper, nonwovens, especially airlaid materials, film or other thin-surface materials as well as single or multi-layer material mixtures are suitable as the first and second layers. For example, SAP, black carbon, zeolite alone, in mixtures, mixed with polymer or other materials are used as absorbent material. In particular, according to the invention, the absorbent pads that can be produced in this way can be used, for example, in the following applications: hygiene articles such as sanitary napkins, diapers or absorbent pads for weaning in nursing mothers, incontinence articles such as absorbent pads, food technology, for example for meat pads and food packaging, absorber pads, in particular for industrial products such as oil absorption, liquid absorption, in particular leakage liquids, furthermore for washing pads, usable in washing machines that have odorous substances or detergents, for example, usable for medical needs, for blood-absorbing materials such as in operating rooms, for coverings, cleaning materials for operating rooms and operating room clothing, for clothing, clothing cleaning agents in general, simultaneously also usable for

Washcloths, cloths, towels, wipes, in the household, for transporting food, for frozen goods, for goods that may lose liquid, as barriers to plug holes caused by swelling, in building structures, to protect against moisture ingress, in particular for storing moisture in the ambient air, for example during dry storage of electronic components or optical devices, as a base as well as a cover.

Claims (12)

1. Device ( 97 ) for the continuous production of an absorbent layer ( 110 ), the device ( 97 ) having at least a first feed for feeding a first layer ( 99 ), a second feed for feeding a second layer ( 101 ) and a suction medium feed in order to arrange at least one absorbent layer therebetween, characterized in that a suction device is arranged in order to suck suction medium from the first layer ( 99 ) at defined points in order to create interruptions along a suction medium path. 2. Device for the continuous production of an absorbent layer ( 165 ), the device having at least a first feed for feeding a first layer ( 147 ), a second feed for feeding a second layer and a suction agent feed in order to arrange at least one absorbent layer ( 10 ) therebetween, characterized in that at least one web ( 148 ) can be applied transversely to a direction of movement on the first layer ( 147 ) in order to form a boundary surface for suction agent to be applied, the web ( 148 ) being designed such that an area on the first layer ( 147 ) is kept free so that the area can subsequently form part of a transverse seal ( 170 ) of an absorbent layer. 3. Device for the continuous production of a first absorbent layer, the device having at least a first feed for a first layer, a second feed for a second layer and a suction agent feed, the suction agent feed arranging a suction agent layer on the first layer before the second feed feeds the second layer to the first layer, characterized in that a binder device for producing a transverse seal to the second feed is arranged such that a binder can be applied to one side of the second layer, which is then connected to a side of the first layer to which a suction agent layer is applied. 4. Device ( 97 ) according to claim 1, 2 or 3, characterized in that a depositing device is connected downstream, which receives individual or interconnected absorbent layers separated from one another by complete sealing. 5. Device ( 97 ) according to one of claims 1 to 4, characterized in that the device, in particular a depositing device, has detection means by means of which sections of the absorbent layer with and without an absorbent layer can be distinguished. 6. Device according to one of the preceding claims, characterized in that a binding agent device ( 108 , 109 ) is arranged upstream or downstream of the suction agent supply, wherein by means of the binding agent device ( 108 , 109 ) a binding agent is assigned at least partially discontinuously to at least one layer ( 99 , 110 ). 7. Device according to one of the preceding claims, characterized in that in addition to a transverse sealing device for producing a transverse seal ( 170 ), a longitudinal sealing device for continuously producing a longitudinal seal ( 171 ) of the suction layer ( 165 ) is present. 8. Device according to one of the preceding claims, characterized in that a sealing device is provided with which at least part of the seal is produced mechanically, wherein a connecting means forms a mechanically acting connection between the first and the second layer. 9. Device according to one of the preceding claims, characterized in that an adhesive application device is arranged such that an adhesive is at least partially applied to the second layer, which is subsequently fed to the first layer carrying the absorbent layer. 10. Absorbent layer ( 165 ) with at least a first layer ( 167 ), a second layer ( 169 ) and an absorbent layer ( 168 ) which is arranged between the first layer ( 167 ) and the second layer ( 169 ), characterized in that a transverse seal ( 170 ) at least partially has a different binder than a longitudinal seal. 11. Suction layer according to claim 15, characterized in that a force to be applied to destroy a transverse seal ( 170 ) is greater than the force to be applied for a longitudinal seal ( 171 ) or vice versa. 12. Suction layer ( 165 ) according to claim 15 or 16, characterized in that it has a marking means by means of which a cutting line can be detected.