How airlaid products are manufactured

Abstract

The present invention relates to a method for producing an airlaid product or nonwoven fabric from a starting material, in particular a pulp material in the form of a bundle, such as a pulp bale, in which the starting material is ground in at least one grinding line by at least one grinding device to form ground material and the ground material is fed to at least one material buffer. The ground material is metered from the at least one material buffer by at least one metering device and fed to at least one processing line with at least one defibration system, in which the ground material is defibrated to form defibrated material. The defibrated material is fed to a production machine for processing into an airlaid product or nonwoven fabric. The at least one metering device is controlled to feed a continuous mass flow rate of defibrated material to the production machine. The present invention further relates to an apparatus for carrying out the method for producing an airlaid product or nonwoven fabric.

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for producing an airlaid product or nonwoven fabric from a starting material, particularly a pulp material in the form of a bundle, such as a pulp bale.

[0002] Such methods and devices are known in principle. Typically, a fluff pulp material, known as fluff-pulp, is used. The fluff pulp material is provided as roll goods, the fluff pulp web wound into a roll not only having a defined thickness and a defined width, but also having other well-defined properties that allow smooth further processing. Thus, fluff pulp is usually of high purity, e.g. 0.65 g / cm 3 It has a uniform density of less than 1000 g / m2 and a uniform moisture content and can be very well defibrated in the dry state, which is also called defibration. This is particularly important since the production of nonwovens and dry products, in particular air-laid products, so-called airlaid products, is usually carried out without the addition of water or other solvents, i.e. "dry". Fluff pulp material as rolled goods is distinguished by good running properties, low required grinding energy and low knot content. The fluff pulp material used is usually already processed to the corresponding desired material properties and has the desired fiber composition, for example a defined long fiber and short fiber proportion.

[0003] When producing nonwoven and dry products from fluff pulp materials, roll goods are usually unwound at a defined web speed, dry defibration (disintegration) and then fed to a nonwoven or dry-laid machine (manufacturing machine). Further processing of the fluff pulp material beyond defibration is omitted, since the roll goods used already have the required properties for further processing. What is characteristic of the known manufacturing methods is that when the fluff pulp material is unwound from the material roll at a constant web speed, due to the well-defined properties of the fluff pulp web, a continuous, in particular constant in time, mass flow rate of the pulp material is formed, which is also fed continuously to the manufacturing machine. The mass flow rate is adjusted via the web speed during unwinding of the fluff pulp material. Finally, the basis weight of the nonwoven or dry product is also adjusted via the mass flow rate of the material fed to the manufacturing machine.

[0004] These special requirements for the starting material of known methods and devices for producing airlaid products or nonwovens make it virtually impossible to use conventional pulp materials in the form of commercially available bundles, as used, for example, in tissue production, when wet producing a wide variety of papers. Generally, pulp can be used in the form of pulp bales, which consist of a number of pulp sheets stacked on top of each other. Compared to fluff pulp materials, pulp bales have significant cost advantages. However, pulp bales or pulp materials that are not generally provided as roll goods with defined dimensions and defined thickness cannot be directly processed into the required continuous mass flow rate of fiberized pulp material. Furthermore, in addition to fiberization, other processing steps, such as cleaning and / or screening, are required, which processing steps may likewise impede the continuous material flow of fiberized pulp material.

[0005] The object of the present invention is to provide a method and an apparatus for producing airlaid products or nonwoven fabrics which is more economical and has more flexible possibilities for use.

[0006] This problem is solved by a method having the features of claim 1 and by a device having the features of claim 16.

[0007] In the method according to the invention for producing an airlaid product or nonwoven fabric from a starting material, in particular a pulp material in the form of a bundle, such as a pulp bale, the starting material is ground in at least one grinding line using at least one grinding device to form ground material, and the ground material is fed to at least one material buffer. The ground material is metered from the at least one material buffer using at least one metering device and fed to at least one processing line with at least one defibration system. In the defibration system, the ground material is defibrated to form defibrated material. The defibrated material is fed to a production machine and processed to form the airlaid product or nonwoven fabric. The at least one metering device is controlled to provide a continuous mass flow rate of defibrated material to the production machine.

[0008] The apparatus for producing an airlaid product or a nonwoven fabric from at least one starting material, in particular a pulp material in the form of a bundle, such as a pulp bale, comprises at least one grinding line with at least one grinding device for grinding the at least one starting material to form at least one grinding material. The apparatus further comprises at least one material buffer for receiving the grinding material respectively assigned thereto, the at least one material buffer having at least one controllable metering device for metering out the respectively assigned grinding material from the at least one material buffer and feeding the at least one grinding material to at least one processing line. The at least one processing line comprises at least one defibration system configured for defibrating the at least one grinding material to form at least one defibrated material. The apparatus further comprises a production machine for producing an airlaid product or a nonwoven fabric from the at least one defibrated material, and a control unit is provided which is adjusted and configured to control the at least one metering device such that a continuous mass flow rate of defibrated material is fed to the production machine. The apparatus according to the invention makes it possible to carry out the production method according to the invention.

[0009] According to the invention, it is proposed that in a first method section, before the starting material is defibrated, it is first comminuted in a comminuting device to form comminuted material and introduced into a material buffer, for example a store, in which the comminuted material is, as it were, stored intermediately, and in a second method section, the comminuted material is fed from the material buffer to the defibration machine and to the production machine.

[0010] The first method section preceding the fiberization, up to the grinding of the starting material and the feeding of the ground material to the material buffer, constitutes a method according to the invention for producing a nonwoven or airlaid product independent of the use of expensive fluff pulp material in roll form, and instead allows the use of any commercially available bundle starting material. For example, pulp bales can be used. This allows for cost and energy savings, since due to the low density of fluff pulp, a higher thermal drying rate is required during the production of fluff pulp compared to conventional pulp materials such as pulp bales. These advantages are likewise achieved by the device according to the invention, in particular by providing at least one grinding line and at least one material buffer with at least one metering device.

[0011] The pulp bales used consist of individual, stable and compact plates of pulp material stacked and bound together to form a bale. Pulp bales differ from the cotton bales which are usually used very frequently in that the latter unravel very easily and require only minor defibration.

[0012] The pulp material plates used are usually 400 g / m 3 Above 600g / m 2 More than 1200 g / m 3 It has the following basis weight: The plates are extremely stable and in order to be crushed they require crushing equipment adapted to this property.

[0013] The method and the device can be used not only for pulp materials, but also quite generally for any starting material that can be dry defibrated, in particular regardless of bundle shape. The starting material can be introduced into the method or device, for example, loosely, slightly pressed or in roll form. For example, waste paper and / or manufacturing waste materials can be processed in the described manner.

[0014] Airlaid products may include dry-laid products from the group of tissue webs, dusters, hand towels, napkins, table covers, paper webs, writing and printing papers, etc. Nonwovens may include dry-laid products from the group of dusters, hand towels, napkins, table covers, etc. The above groups of products should be understood to be merely exemplary and do not represent a complete list.

[0015] In the first method step, the starting material is ground to a ground material having a certain maximum fragment size, which is in particular stackable and meterable and is stacked or otherwise temporarily stored in a material buffer. The material buffer, for example the storage section, is preferably designed or dimensioned in such a way that the method steps preceding the stacking or intermediate storage of the ground material can be carried out independently of the method steps following the stacking or intermediate storage of the ground material. Thus, a batch operation in the grinding line or in the first method section is possible, in which a stock of ground material is produced in the material buffer.

[0016] In a second method section following the stacking or intermediate storage, the ground material is defibrated (disintegrated) and generally fed to a continuously operating production machine. To obtain a uniform airlaid product or a uniform nonwoven fabric, a continuous, in particular constant mass flow rate of defibrated material is therefore required. According to the invention, providing a continuous mass flow rate of defibrated material is made possible by metering the removal of ground material from at least one material buffer by means of at least one metering device, in particular in a controlled (open-loop controlled) or regulated (closed-loop controlled) manner. The at least one metering device can feed a purposefully defined amount of ground material per unit of time to the processing line.

[0017] Advantageous configurations of the invention emerge from the dependent claims, the description and the drawings.

[0018] According to a preferred embodiment, all steps of the method for producing a nonwoven or airlaid product are carried out in a continuous production line. Thus, all components of the apparatus for producing an airlaid or nonwoven product may be integrated into one common production line. No transport of material intermediate products away from the continuous production line or production of additional intermediate products on separate processing lines located outside the continuous production line is provided.

[0019] The metering device can be controlled, in particular by the control unit, on the basis of characteristic parameters of the mass flow rate of the defibrated material, detected by the sensor system. The mass flow rate of the defibrated material is particularly important for the airlaid material or nonwoven fabric being produced, since this mass flow rate directly corresponds to the amount of material fed to the production machine to be processed by the production machine. For example, at least one processing line may have a sensor device in the defibrating system or downstream of the defibrating system, which sensor device in particular optically measures the mass flow rate of the defibrated material before it is fed to the production machine. Based on the determined mass flow rate of the defibrated material, the amount of ground material discharged from the material buffer by the metering device can be adapted to form the desired mass flow rate of the defibrated material.

[0020] According to another embodiment, the metering device is controlled, in particular by a control device, based on a characteristic parameter of the produced airlaid product or nonwoven fabric detected by a sensor system, in particular in this case the parameter is the basis weight, in which case the amount of ground material discharged is directly adjusted based on the properties of the airlaid product or nonwoven fabric being produced, thereby intentionally improving the quality or uniformity of the airlaid product or nonwoven fabric.

[0021] The metering device can also be controlled in such a way that a continuous mass flow of the ground material is fed to the process line assigned to it. If in this procedure and in the configuration of the production plant it can be assumed that the continuous mass flow fed to the process line also automatically becomes, so to speak, a continuous mass flow for the production machine, then in some circumstances it is possible to dispense with further complex sensor systems or regulation techniques, since only a corresponding control of the metering device is required.

[0022] In particular, for the production of a multi-layered product with at least two layers of an airlaid product or nonwoven fabric, the ground material can be metered by at least two metering devices, taken from a material buffer assigned to the at least two metering devices, and fed to at least two processing lines each with one defibration system. In the defibration system, the ground material is respectively defibrated to form a defibrated material. Each of the at least two metering devices can be assigned to one of the at least two processing lines. The defibrated material of the at least two processing lines can be fed to the same production machine, where it can be processed to form, in particular, a multi-layered airlaid product or nonwoven fabric. In principle, more than two metering devices can be assigned to one material buffer, each metering device of the material buffer being provided for charging one processing line. The processing lines can serve, for example, to process material for a product layer for the airlaid product to be produced or the nonwoven fabric to be produced.

[0023] If provided, the at least two metering devices of the material buffer can be controlled independently of one another, so that at least two different processing lines assigned to each of the at least two metering devices can be charged with defined amounts of ground material from the material buffer independently of one another, in particular differently, thereby making it possible to produce, for example, different types of product layers of airlaid products or nonwovens.

[0024] In the method and / or the apparatus, at least two different starting materials, in particular pulp materials, can be used. For example, long fiber pulp, short fiber pulp, waste materials and / or other starting materials can be used depending on the product requirements and the requirements of the manufacturing machine. The at least two different starting materials can be introduced into the method or the apparatus in separate, material-specific bundles or bundles that already contain a material mixture.

[0025] According to an embodiment, at least two different starting materials are ground in the same grinding line or grinding device, in particular separately, to form at least two different ground materials. The grinding of the at least two different starting materials can be carried out in succession, for example, using the same grinding device.

[0026] According to another embodiment, at least two different starting materials are ground by at least two grinding lines or grinding devices to form at least two different ground materials. The equipment or production line for producing nonwoven or airlaid products may have two different grinding devices or grinding lines for this purpose. These grinding devices or grinding lines may each have different specifications that are particularly suitable for a particular starting material. Thus, a high grinding quality of the at least two different ground materials can be guaranteed.

[0027] Each of the at least two different grinding materials can be fed into a separate material buffer. The differently ground materials can be stored or stacked separately from each other in their own material buffers and can be withdrawn separately from the material buffers.

[0028] According to an embodiment, each processing line can be supplied with a defined material composition consisting of at least two different grinding materials from at least two material buffers by means of metering devices respectively assigned to these material buffers. The at least two different grinding materials can be defibrated together by the defibration system of the processing line, and the at least two defibrated materials are mixed to obtain a homogeneously defibrated material. The different grinding materials from the different material buffers can be freely mixed in any ratio, as the metering devices of the material buffers are correspondingly controlled, in particular by means of a control unit.

[0029] Basically, any number of grinding lines with any number of grinding devices, any number of material buffers and any number of processing lines with defibration systems can be combined independently of one another to obtain the desired installations or production lines. Thus, a highly flexible production method is provided that can be adapted to a multitude of product requirements, which can be configured according to the required production volume, the pulp material used and the capacity of the individual machines. If multi-layer products are produced, the flexibility of the method also allows different material compositions of the individual product layers.

[0030] At least one starting material can be ground and / or defibrated at least substantially dry, in particular without the addition of water or solvents, by means of at least one grinding device. In particular, it may be provided that the moisture content of the starting material, the ground material and / or the defibrated material does not exceed a value of 10%, in particular a value of 8% or 7%, during the production process.

[0031] According to an embodiment, the at least one ground material is screened with respect to a characteristic parameter, in particular by means of a screen and / or a cyclone separator. Alternatively or additionally, the at least one defibrated material can be screened with respect to a characteristic parameter, in particular by means of a screen and / or a cyclone separator. The characteristic parameter can be, for example, the fragment size of the ground or defibrated material, with material above the maximum fragment size being screened and possibly fed again for grinding or defibration. Thus, a high homogeneity of the ground and / or defibrated material is ensured, which has a favorable effect on the subsequent method steps and ultimately on the quality of the nonwoven or airlaid product produced.

[0032] According to another embodiment, the at least one ground material is cleaned, in particular by means of a cyclone separator and / or a magnetic separator. Alternatively or additionally, the at least one defibrated material can be cleaned, in particular by means of a cyclone separator and / or a magnetic separator. To obtain a clean and homogeneous ground and / or defibrated material, obstacles, for example metallic foreign bodies and / or heavy parts, can be removed from the ground and / or defibrated material.

[0033] According to another embodiment, the material buffer is suitable for accommodating at least one, preferably two bundles of pulp material being fed, in particular one, preferably two pulp bales. Advantageously, the material buffer is designed to allow buffering of at least one, preferably two entire pulp bales and to bridge changeover times in case of intermittent feeding of the bales. The buffer size is important for the continuous operation of the subsequent machine.

[0034] According to another embodiment, the material buffer is arranged downstream of the pulp material grinding device and upstream of the defibration system, in order to allow buffering upstream of the defibration system and continuous operation of the defibration system, preferably a hammer mill, which is advantageous for the lifespan of the defibration system used, preferably a hammer mill, which is less worn during continuous feeding, and for the continuous quality, since differences would occur between the initial and final defibrated pulp material during intermittent operation.

[0035] According to another embodiment, the pulp material used is 400 g / m 3 Above 600g / m 2 More than 1200g / m 3 The starting material has a grammage of 1000 g / m² / g, which advantageously allows the required amount of starting material to be stored space-savingly and in a compact manner. However, the high grammage also places special demands on the grinding equipment used.

[0036] According to another embodiment, the machine making the airlaid product or nonwoven is a paper machine and / or a tissue machine.

[0037] According to another embodiment, the starting material is provided solely by pulp bales. Advantageously, no expensive roll goods are used.

[0038] In the following, preferred embodiments of the invention will be described purely by way of example with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0039] [Figure 1] 1 is a schematic diagram showing a prior art apparatus for producing nonwoven or airlaid products made from fluff pulp material. [Diagram 2] FIG. 1 is a schematic diagram showing a production apparatus according to the invention for nonwoven or airlaid products made of bale-like starting material, comprising a grinding line, at least one material buffer and at least one processing line with a fiberization system. [Diagram 3] FIG. 1 is a schematic diagram showing an apparatus according to the invention for producing a three-layer nonwoven or three-layer airlaid product from a bale of starting material, comprising two grinding lines, three material buffers and three processing lines each with a fiberization system.

[0040] 1 shows a schematic diagram of a prior art apparatus 10 for producing an airlaid product or nonwoven fabric 16 from fluff pulp material, provided in the form of a fluff pulp material web 14 wound on a material roll 12. The fluff pulp material is unwound from the material roll 12 at a defined web speed and fed to a processing line 11 equipped with a fiberizing system 18, in which the fluff pulp material web 14 is fiberized. The fiberized pulp material is then fed to a manufacturing machine 20, in which the airlaid product or nonwoven fabric 16 is produced from the fiberized pulp material.

[0041] Since the fluff pulp material web 14 has defined dimensions and a uniform density, by unwinding the fluff pulp material web 14 from the material roll 12 at a defined web speed, a continuous material flow with a constant mass flow rate of fluff pulp material is provided in the device 10, which is fed to a continuously operating manufacturing machine 20. The mass flow rate of the defibrated pulp material can be detected by a sensor device 22 between the defibration system 18 and the manufacturing machine 20. If the detected mass flow rate deviates from a target mass flow rate, the mass flow rate can be adjusted to the target mass flow rate by adapting the web speed when unwinding the fluff pulp material web 14 from the material roll 12 (adjustment 24).

[0042] Optionally, additional materials can be fed to the machine 20, which is shown in FIG. 1 with dashed lines to emphasize its optional nature. On the one hand, one or more materials 26 already prepared can be fed to the machine 20 together with the pulp material defibrated by the defibration system 18. On the other hand, the device 10 can include a second processing line 28 in which a second fluff pulp material web 32 is unwound from a second material roll 30 and fed to a second defibration system 34 at a defined web speed, so that a continuous mass flow of a second defibrated material is produced. This second defibrated material can also be fed to the machine 20, and in the second processing line 28, the adjustment 38 of the web speed as described above can also be performed by a second sensor device 36.

[0043] The prior art device 10 requires the use of fluff pulp material webs 14, 32 in the form of defined and unreelable rolls of material 12, 30, since only in this way can it be guaranteed that a continuous mass flow of fluff pulp material is supplied to the machine 20.

[0044] Instead, the apparatus of the present invention is configured and constructed to allow the use of starting materials in any bonded form. Figure 2 shows an apparatus 40 for producing an airlaid product or nonwoven fabric 16 from at least one starting material 42. The essential components of the apparatus 40 are shown in solid lines, and the optional components are shown in dashed lines.

[0045] 2, all components or elements of the apparatus 40 are arranged in one continuous common production line in which a method for producing an airlaid product or nonwoven fabric 16 can be performed. In the following, the basic functional form of the apparatus 40 and the production method that can be performed using the apparatus 40 will be described first with respect to the basic apparatus components and method steps.

[0046] As starting material, in FIG. 2, a pulp material in the form of a pulp bale 45 is provided, which is formed by pulp sheets (not shown) stacked one on top of the other. Basically, any bundle of starting material 42 can be used. Firstly, the starting material 42, for example the entire pulp bale 45 or a part of the pulp bale 45, is fed to a grinding line 46 of the device 40. This grinding line 46 includes a grinding device 48, which grinds the starting material 42 to form a ground material. It is provided that the starting material 42 is ground dry without the addition of water.

[0047] The crushing device 48 may, for example, comprise a single-shaft or multi-shaft crusher. The crushing device 48 may be equipped with a screen, which defines the maximum fragment size of the crushed material to be removed from the crushing device 48, thus making this material at least partially homogenized and meterable. The removal of the crushed material from the crushing device 48 can take place, for example, by a conveyor belt, a conveyor screw or a suction box. The removal is preferably carried out by a suction box or a conveyor screw with an assisted suction section. The suction section prevents the accumulation of dust in the area of ​​the crushing device 48. Furthermore, a smooth removal of the crushed material, assisted by suction, has a favorable effect on the grinding quality.

[0048] The device 40 comprises a material buffer 50, for example a storage, which is provided for receiving the grinding material. To supply the grinding material to the material buffer 50, the material can be fed from the outlet of the grinding device 48 into an air passage and transported in the direction of the material buffer 50 by an air flow. The air flow can be formed by a conveying fan with an open impeller, which is arranged downstream of the grinding device in the material flow of the grinding material. Alternatively or additionally, an energy-efficient conveying fan with a closed impeller can also be provided. This conveying fan can in particular be connected downstream of the material buffer 50, where the grinding material has already been separated from the air flow and is stacked in the material buffer 50 or is intermediately stored in another form. For separating the grinding material from the air flow and / or for intermediately storing the grinding material in the material buffer 50, a cyclone separator and / or a screen separator can also be provided which is provided in particular for this purpose.

[0049] The material buffer 50 may be dimensioned to accommodate a larger amount of ground material than can be fed to the grinding device 48 at one time. The material buffer 50 thus enables a batch operation in the grinding line 46, i.e. a series of bundles of starting material 42, for example a number of pulp bales 45, can be ground by the grinding device 48 to form ground material, which can then be fed to the material buffer 50 and, if necessary, intermediately stored in the material buffer 50. In this respect, the first method section 52, from the grinding of the starting material 42 to the intermediate storage of the ground material in the material buffer 50, can be carried out independently of the subsequent production steps. This is indicated in FIG. 2 by the dashed and dotted line, above which the first method section 52 (batch operation) is shown.

[0050] The second method section 53 (continuous or so to speak continuous operation) begins with the removal of ground material from the material buffer 50 (FIG. 2, below the dashed line), which for this purpose has a controllable metering device 54, by means of which the ground material can be metered out of the material buffer 50. The metering device 54 supplies the ground material to a processing line 56. The controllable metering device 54 can be configured as a speed-controlled conveyor screw, which performs the removal and metering of the ground material piled up in the material buffer 50 and supplies a controlled mass flow rate of ground material to the processing line 56.

[0051] The processing line 56 includes a defibration system 58, which defibrates the pulverized material to form a defibrated material. The resulting defibrated material is then fed to a production machine 60 of the device 40, where the airlaid product or nonwoven fabric 16 is produced from the defibrated material. The defibration system 58 can be fed by a conveyor belt, a conveyor screw or by means of an air flow. According to an advantageous embodiment, the pulverized material is fed directly into a passage assigned to the processing line 56 by means of a controllable metering device 54 and fed to the defibration system 58 by means of an air flow formed by a conveying fan. The material buffer 50 and the defibration system 58 can be positioned spatially independent of each other in this type of feeding and can be flexibly connected by means of a passage of the processing line 56. Furthermore, due to the high conveying speed of the air flow, changes in the metering of the ground material fed to the processing line 56 made by the metering device 54 are effective with very small time delays in the fiberization system 58 and thus ultimately in the manufacturing machine 60, allowing a particularly direct control of the production process, which ultimately has an advantageous effect on the quality of the produced airlaid product or nonwoven fabric 16.

[0052] The fiberization system 58 is configured to fiberize the pulverized material in a substantially dry state without the addition of water. The fiberization system 58 may include at least one first hammer mill for fiberizing the pulverized material. To achieve improved fiberization quality, the fiberization system 58 may additionally have a second hammer mill downstream of the first hammer mill. The first hammer mill may be equipped with a screen to prevent the complete, unfibered portion of the pulverized material from leaving the first hammer mill and reaching the second hammer mill. The second hammer mill may have hammers that are finer and strike more closely than the first hammer mill, removing any nodes that may be present from the fiberized material by the first hammer mill, which ultimately has a favorable effect on the quality of the airlaid product or nonwoven fabric 16 produced.

[0053] The dry defibrated pulp material is then fed to the machine 60 by an air flow generated by a conveying fan, for example via a passage system connected to the defibrating system 58. The machine 60 may be a conventional continuously operating machine 60, whereby a continuous mass flow of defibrated material must be fed to the machine 60 in order to obtain a uniform airlaid product or a uniform nonwoven fabric 16. To achieve this, it is provided that the metering device 54 is controlled so that a continuous mass flow of defibrated material is fed to the machine 60. For this purpose, the device 40 has a control unit 62, which is constructed and configured in a corresponding manner to control the controllable metering device 54.

[0054] The control of the metering device 54 is based on a characteristic parameter of the mass flow rate of defibrated material between the defibrating system 58 and the production machine 60 according to Fig. 2. To determine the mass flow rate of defibrated material, a sensor device 64 is installed, for example in a passage system, immediately downstream of the defibrating system 58 or possibly downstream of the cleaning device 70 and / or downstream of the sorting device 72, which detects the actually existing mass flow rate, for example by means of a camera system or another suitable sensor. The actually detected mass flow rate is used as a control variable for the controllable metering device 54. If the actually detected mass flow rate deviates from the setpoint mass flow rate, the metering device 54 is controlled or post-adjusted (adjustment 55) in order to achieve this setpoint mass flow rate.

[0055] Alternatively, the control of the metering device 54 can be based on characteristic parameters of the produced airlaid product or nonwoven fabric 16, for example on the actual basis weight of the airlaid product or nonwoven fabric 16, detected using a suitable sensor system. If the actually detected basis weight deviates from the target basis weight, the metering device is controlled or adjusted accordingly in order to feed an adapted amount of ground material to the processing line and thus achieve the target basis weight. In principle, the metering device 54 can be controlled such that a continuous, in particular constant, i.e. time-invariant mass flow rate of ground material is fed to the processing line 56.

[0056] In Fig. 2, further optional components of the device 40 are shown in dashed lines. The grinding line 46 includes a cleaning device 66, which is connected downstream of the grinding device 48 and is arranged, for example, in a passage system for conveying the ground material. The cleaning device 66 may include a magnetic separator for removing metallic foreign bodies from the ground material. Downstream of the cleaning device 66, a sorting device 68 may be connected, which may include, for example, a cyclone separator, which ejects the heavy fraction, after which the ground, cleaned and sorted material is fed to the material buffer 50.

[0057] In a similar manner, alternatively or additionally, a cleaning device 70 and / or a sorting device 72 may be arranged in the processing line 56 downstream of the fiberization system 58 to clean the fiberized material of foreign objects and obstacles and to sort the fiberized material, for example with respect to its fragment size. For this purpose, magnetic separators, cyclone separators and / or screen separators may be used.

[0058] Furthermore, the device 40 may have a feed 74 upstream of the production machine 60 for further material that has already been processed. The device 40 may also have a second processing line 56.2, which can be supplied with ground material by a second controllable metering device 54.2 of the material buffer 50. Each processing line 56, 56.2 is thus assigned a separate, controllable metering device 54, 54.2, which supplies the processing line 56, 56.2 with ground material from the material buffer 50. Conversely, the material buffer 50 has a separate metering device 54, 54.2 for each processing line 56, 56.2. The metering devices 54, 54.2 can be controlled independently of one another, so that each processing line 56, 56.2 can be supplied with an individually definable amount of ground material from the material buffer 50.

[0059] Similar to the processing line 56, the second processing line 56.2 includes a second defibration system 58.2 for defibrating the ground material. Furthermore, as described above in relation to the first processing line 56, the second processing line 56.2 may be provided with a second cleaning device 70.2 and a second screening device 72.2. In the second processing line 56.2, a second sensor device 64.2 is arranged immediately downstream of the second defibration system 58.2 or downstream of the second cleaning device 70.2 or the second screening device 72.2. This second sensor device 64.2 detects the mass flow rate of the defibrated material. If the actual detected mass flow rate deviates from the target mass flow rate defined for the second processing line 56.2, the second metering device 54.2 assigned to the second processing line 56.2 is subsequently adjusted or controlled (adjusted 55.2) based on this in order to achieve the target mass flow rate.

[0060] When producing a multi-layer airlaid product or nonwoven fabric 16, each of the processing lines 56, 56.2 may be provided to defibrate the starting material 42 for one product layer and feed it to the production machine 60. Each processing line 56, 56.2 may be charged with the appropriate amount of comminuted starting material for this purpose by means of an assigned metering device 54, 54.2.

[0061] For the production of the airlaid product or nonwoven fabric 16, different materials can be used, in particular besides the starting material 42, a second starting material 43 and a third material 44. For example, as starting material 42, long fiber pulp can be used, as second starting material 43, short fiber pulp, each in the form of a bale, and as third starting material 44, already ground waste material (FIG. 2, top right). The device 40 can have separate material buffers for each of the materials 42, 43, 44, in particular a second material buffer 76 for receiving the second starting material 43 and a third material buffer 78 for receiving the separately provided waste material 44, which may have been pretreated.

[0062] Since the long-fiber pulp bales and the short-fiber pulp bales behave similarly during grinding, the long-fiber pulp bales and the short-fiber pulp bales can be ground in the grinding line 46 by the same grinding device 48 and can optionally be cleaned and sorted by means of the same cleaning device 66, in particular the same magnetic separator, and the same sorting device 68, in particular the same cyclone separator. The grinding, cleaning and sorting of the starting materials 42, 43 are carried out separately, i.e., for example one after the other, so that the resulting ground material each only contains one material type. In order to deposit the different ground materials in the material buffers 50, 76 assigned to these materials, respectively, the passage system of the grinding line 46 can be switched so that the ground material from the long-fiber pulp 42 is fed to the storage 50 and the ground material from the short-fiber pulp 43 is fed to the storage 76. The already ground waste material 44 is fed to a third material storage 78. To stack the respective materials 42, 43, 44, each material buffer 50, 76, 78 preferably includes a cyclone type separator and / or a screen separator.

[0063] The second material buffer 76 and the third material buffer 78 may also each have two metering devices 80, 80.2 or 82, 82.2, which are each assigned to one of the processing lines 56, 56.2 and can be controlled independently of one another. Thus, via the control unit 62, each of the two processing lines 56, 56.2 can be supplied with a defined material composition having a freely selectable proportion of the ground material of the long fiber pulp 42, the short fiber pulp 43 and the waste material 44 independently of one another. All the ground material supplied to the respective processing line 56, 56.2 is defibrated together in the defibration system 58, 58.2 arranged in the corresponding processing line 56, 56.2 and mixed therein. Thus, a multi-layered, according to FIG. 2 two-layered airlaid or nonwoven product 16 can be produced with different material compositions of the individual product layers.

[0064] By means of the sensor devices 64, 64.2 of both process lines 56, 56.2, the mass flow rates in the respective process lines 56, 56.2 can be determined, as already explained for the metering devices 54, 54.2 of the material buffer 50. On the basis of the data detected by the sensor device 64, the metering devices 54, 80, 82 assigned to the process line 56 are adjusted or controlled (adjustment 55, 81, 83). On the basis of the data detected by the second sensor device 64.2, the metering devices 54.2, 80.2, 82.2 assigned to the second process line 56.2 are adjusted or controlled (adjustment 55.2, 81.2, 83.2).

[0065] 3 shows another apparatus 40 for producing a three-layer airlaid product or nonwoven fabric 16 from three different starting materials 42, 43, 44, which are each fed to the apparatus 40 in the form of a bale. As explained in relation to FIG. 2, the starting materials may be, for example, long fiber pulp 42, short fiber pulp 43 and waste material 44. To grind the starting materials 42, 43, 44, the apparatus 40 has a first grinding line 46.1 for the long fiber pulp material 42 and the short fiber pulp material 43 (see FIG. 2) and a second grinding line 46.2 for the waste material 44, which include grinding devices 48.1, 48.2, cleaning devices 66.1, 66.2 and sorting devices 68.1, 68.2, respectively. For the waste material 44, a separate crushing device 48.2 and separate magnetic and cyclone separators are preferably used for cleaning and sorting, since this allows adaptation to the requirements of the waste material 44 with regard to shape, material properties and production volume. Thus, the long-fiber and short-fiber pulp materials 42, 43 can be crushed independently of the waste material 44, the crushing quality can be improved for all starting materials 42, 43, 44, and typically, due to the smaller amounts of waste material used, smaller machines can be used in the second crushing line 46.2, thus saving energy.

[0066] Each of the three starting materials 42, 43, 44 to be milled is fed into a separate material buffer 50, 76, 78. In order to produce, in particular, three product layers each having an individual material composition, the apparatus has a first processing line 56.1, a second processing line 56.2 and a third processing line 56.3. Each of the material buffers 50, 76, 78 thus has three independently controllable metering devices, of which one first metering device 54.1, 80.1, 82.1 is provided for charging the first processing line 56.1, one second metering device 54.2, 80.2, 82.2 is provided for charging the second processing line 56.2 and one third metering device 54.3, 80.3, 82.3 is provided for charging the third processing line 56.3. Using fiberizer systems 58.1, 58.2, 58.3 for each processing line 56.1, 56.2, 56.3, the ground material fed to the fiberizer systems 58.1, 58.2, 58.3, respectively, is fiberized and homogenously mixed and then fed to a manufacturing machine 60 which produces a three layer airlaid product or nonwoven fabric 16.

[0067] Each of the three processing lines 56.1, 56.2, 56.3 has its own sensor device 64.1, 64.2, 64.3, which is arranged between the respective grinding system 58.1, 58.2, 58.3 and the production machine 60, as described above in connection with Fig. 2, and detects the mass flow rate of defibrated material in the respective processing line 56.1, 56.2, 56.3. The comparison of the mass flow rate detected in each processing line 56.1, 56.2, 56.3 with the target mass flow rate is used as a basis for controlling the first metering device 54.1, 80.1, 82.1, the second metering device 54.2, 80.2, 82.2 and / or the third metering device 54.3, 80.3, 82.3, as the case may be, so that the target mass flow rate is reached and correspondingly a continuous, in particular constant in time, mass flow rate is supplied to the production machine 60.

[0068] From the above described embodiments it is clear that the concept according to the invention can be adapted in a simple manner to the respective requirement profile. The three processing lines 56.1, 56.2, 56.3 may be independent and thus the three layers of the airlaid product or nonwoven 16 may each be composed of the three materials 42, 43, 44 independently. [Explanation of symbols]

[0069] 10 Prior art devices 11 Processing Line 12 Material roll 14 Fluff pulp material web 16 Airlaid products or nonwoven fabrics 18 Fiber Disintegration System 20 Manufacturing machine 22 Sensor device 24 Adjustment of web speed of first processing line 26 Supply section for processed materials 28 Second Processing Line 30 Second material roll 32 second fluff pulp material web 34 Second Fiber Defibration System 36 Second sensor device 38 Adjustment of web speed of second processing line 40 Airlaid products or nonwoven fabric manufacturing equipment 42 Starting Materials 43 Second Starting Material 44 Third Starting Material 45 Pulp Bale 46 Crushing Line 46.1 First grinding line 46.2 Second grinding line 48 Crushing Equipment 48.1 First grinding device 48.2 Secondary grinding device 50 Material Buffers 52 First method division 53 Second Method Division 54 Controllable metering device for material buffer 54.1 Controllable first metering device for material buffer 54.2 Controllable second metering device for material buffer 54.3 Controllable third metering device for material buffer 55 Adjustment of material buffer metering device 55.2 Adjustment of the second metering device of the material buffer 56 Processing Line 56.1 First Processing Line 56.2 Second Processing Line 56.3 Third Processing Line 58 Fiber Disintegration System 58.1 First fiberization system 58.2 Secondary fiberizing system 58.3 The third fiberization system 60 Manufacturing machine 62 Control Unit 64 Sensor Device 64.1 First Sensor Device 64.2 Second Sensor Device 64.3 Third Sensor Device 66 Cleaning equipment for crushed materials 66.1 Cleaning device for grinding material of the first grinding line 66.2 Cleaning device for grinding material of the second grinding line 68 Sorting equipment for crushed materials 68.1 Sorting device for crushed material of the first crushing line 68.2 Separation device for crushed material of the second crushing line 70 Cleaning equipment for defibrated materials 70.2 Secondary cleaning device for defibrated material 72 Sorting equipment for defibrated materials 72.2 Secondary sorting device for defibrated material 74 Separate Material Supply Section 76 Second Material Buffer 78 3rd Material Buffer 80 Controllable metering device for second material buffer 80.1 Controllable first metering device for the second material buffer 80.2 Controllable second metering device for the second material buffer 80.3 Controllable third metering device for second material buffer 81 Adjustment of the metering device of the second material buffer 81.2 Adjustment of the second metering device of the second material buffer 82 Controllable metering device for the third material buffer 82.1 Controllable first metering device for the third material buffer 82.2 Controllable second metering device for third material buffer 82.3 Controllable third metering device for third material buffer 83 Adjustment of the metering device of the third material buffer 83.2 Adjustment of the second metering device of the third material buffer

Claims

1. A method for manufacturing an airlaid product or a nonwoven fabric (16) from a starting material (42), in particular a pulp material in the form of a bundle, such as pulp bale (45), comprising: pulverizing the starting material (42) in at least one pulverizing line (46, 46.1, 46.2) with at least one pulverizing device (48, 48.1, 48.2) to form a pulverized material; feeding the pulverized material to at least one material buffer (50, 76, 78); metering the pulverized material with at least one metering device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3), removing it from the at least one material buffer (50, 76, 78), and feeding it to at least one processing line (56, 56.1, 56.2, 56.3) equipped with at least one defibering system (58, 58.1, 58.2, 58.3), wherein in the at least one defibering system (58, 58.1, 58.2, 58.3), the pulverized material is defibered to form a defibered material; feeding the defibered material to a manufacturing machine (60) and processing it to form an airlaid product or a nonwoven fabric (16); and controlling the at least one metering device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) such that a continuous mass flow of defibered material is supplied to the manufacturing machine (60).

2. The method according to claim 1, wherein all steps of the method are carried out on a continuous production line.

3. The method according to claim 1 or 2, wherein the metering device is controlled based on characteristic parameters of the mass flow of the defibered material detected by a sensor system (64, 64.1, 64.2, 64.3).

4. The method according to claim 1 or 2, wherein the metering device is controlled based on characteristic parameters of the manufactured airlaid product or the nonwoven fabric (16) detected by a sensor system, particularly wherein the parameter is basis weight.

5. The method according to claim 1 or 2, wherein the metering device is controlled such that a continuous mass flow of pulverized material is supplied to the processing line (56, 56.1, 56.2, 56.3) assigned to the metering device.

6. In particular, for manufacturing a multi-layer product comprising at least two layers of an airlaid product or a nonwoven fabric (16), the ground material is metered by at least two metering devices and taken out from material buffers (50, 76, 78) assigned to the at least two metering devices, and supplied to at least two processing lines (56, 56.1, 56.2, 56.3) each provided with one defibering system (58, 58.1, 58.2, 58.3). In the defibering systems (58, 58.1, 58.2, 58.3), the ground material is defibered respectively to form defibered materials. Each of the at least two metering devices is assigned to one of the at least two processing lines (56, 56.1, 56.2, 56.3). The defibered materials of the at least two processing lines (56, 56.1, 56.2, 56.3) are supplied to the same manufacturing machine (60) and processed in the manufacturing machine (60) to form in particular a multi-layer airlaid product or a nonwoven fabric (16). The method according to claim 1 or 2.

7. The method according to claim 1 or 2, wherein when present, at least two metering devices of the material buffers (50, 76, 78) are controlled independently of each other.

8. The method according to claim 1, using at least two different starting materials (42, 43, 44), in particular pulp materials, that are different from each other.

9. The method according to claim 8, wherein the at least two different starting materials (42, 43, 44) that are different from each other are ground, in particular separately, by the same grinding line (46) or grinding device (48) to form at least two different ground materials.

10. The method according to claim 8, wherein the at least two different starting materials (42, 43, 44) that are different from each other are ground by at least two grinding lines (46.1, 46.2) or grinding devices (48.1, 48.2) to form at least two different ground materials.

11. The method according to claim 9 or 10, wherein each of the at least two different ground materials is supplied to a separate material buffer (50, 76, 78).

12. The method according to claim 1 or 2, wherein a defined material composition consisting of at least two different comminuted materials from at least two material buffers (50, 76, 78) can be supplied to each processing line (56, 56.1, 56.2, 56.3) by metering devices respectively assigned to said material buffers (50, 76, 78).

13. The method according to claim 1 or 2, wherein said at least one starting material (42, 43, 44) is comminuted and / or defibered by said at least one comminuting device (48, 48.1, 48.2) at least substantially dry, in particular without the addition of water or solvent.

14. The method according to claim 1 or 2, wherein said at least one comminuted material is sorted with respect to characteristic parameters, in particular by means of screens and / or cyclone separators (68, 68.1, 68.2), and / or said at least one defibered material is sorted with respect to characteristic parameters, in particular by means of screens and / or cyclone separators (72, 72.2).

15. Said at least one comminuted material is cleaned, in particular by means of cyclone separators and / or magnetic separators (66, 66.1, 66.2), and / or Said at least one defibered material is cleaned, in particular by means of cyclone separators and / or magnetic separators (70, 70.2), in the method according to claim 1 or 2.

16. An apparatus (40) for manufacturing an airlaid product or a nonwoven fabric (16) from at least one starting material (42, 43, 44), in particular from a pulp material in the form of a bundle, such as pulp bale (45), said apparatus (40) comprising At least one comminuting line (46, 46.1, 46.2) comprising at least one comminuting device (48, 48.1, 48.2) for comminuting said at least one starting material (42, 43, 44) to form at least one comminuted material, and At least one material buffer (50, 76, 78) for accommodating comminuted materials respectively assigned to said material buffers (50, 76, 78). including, wherein the at least one material buffer (50, 76, 78) measures and extracts the respectively assigned comminuted material from the at least one material buffer (50, 76, 78), and each has at least one controllable metering device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) for supplying the at least one comminuted material to at least one processing line (56, 56.1, 56.2, 56.3), and the at least one processing line (56, 56.1, 56.2, 56.3) includes at least one defibrating system (58, 58.1, 58.2, 58.3), and the at least one defibrating system (58, 58.1, 58.2, 58.3) is configured to defibrate the at least one comminuted material to form at least one defibrated material, the apparatus (40) further comprises, a manufacturing machine (60) for manufacturing an airlaid product or a nonwoven fabric (16) from the at least one defibrated material, a control unit (62) is provided, and the control unit (62) is configured and formed to control the at least one metering device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) such that a continuous mass flow of defibrated material is supplied to the manufacturing machine (60) by the method according to claim 1 or 2 in particular, apparatus (40). [

17. ] The apparatus according to claim 16, wherein all components of the apparatus are arranged on one common production line.

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