Method for producing airlaid products

Abstract

The invention relates to a method for producing an airlaid product or a nonwoven material from a starting material, in particular a cellulose material in the form of packaging, such as a cellulose bale. In said method, the starting material is comminuted into a comminuted material in at least one comminution line by means of at least one comminuting device, and the comminuted material is supplied to at least one material buffer. The comminuted material is removed from the at least one material buffer in a metered manner by means of at least one metering device and is supplied to at least one processing line with at least one defiberizing system in which the comminuted material is defiberized into a defiberized material. The defiberized material is supplied to a production machine and is processed into an airlaid product or a nonwoven product, wherein the at least one metering device is controlled such that a continuous mass flow of defiberized material is supplied to the production machine. The invention additionally relates to a device for carrying out the method for producing an airlaid product or a nonwoven product.

Description

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

[0002] Such methods and devices are generally known, for example from EP 3 450 125 A1 and US 2003 / 089478 A1.

[0003] Typically, fluff pulp is used. The fluff pulp material is delivered in rolls, whereby a fluff pulp web wound into a roll not only has a defined thickness and width, but also other well-defined properties that enable smooth further processing. For example, the fluff pulp usually has a high degree of purity, a uniform density of, for example, less than 0.65 g / cm³, and a uniform moisture content. It can be easily defibrated in a dry state. This is particularly relevant because the production of nonwovens and dry-laid products, especially air-laid or so-called airlaid products, is usually carried out "dry" without the addition of water or other solvents.Fluff pulp material in roll form is characterized by good runnability, low shredding energy requirements, and low knot content. The fluff pulp material used is usually already processed according to the desired material properties and has a desired fiber composition, for example, a specific long and short fiber ratio.

[0004] In the production of nonwoven products and dry-laid products from fluff pulp material, the roll material is usually unwound at a defined web speed, fed to dry defibration (defibration), and then fed to a nonwoven or dry-laying machine (production machine). Any further processing of the fluff pulp material beyond defibration is unnecessary, as the roll material already possesses the properties required for further processing. A characteristic of this known production process is that when the fluff pulp material is unwound from the material roll at a constant web speed, a continuous, particularly temporally constant, mass flow of pulp material is generated due to the well-defined properties of the fluff pulp web, which is also continuously fed to the production machine.The mass flow is adjusted by the web speed during unwinding of the fluff pulp material. Ultimately, the basis weight of the nonwoven or dry-laid product is also adjusted by the mass flow of the material fed into the production machine.

[0005] These special requirements of known manufacturing processes and equipment for airlaid products or nonwovens on the starting material make the use of conventional pulp materials in commercially available containers, as used for a wide variety of wet-made paper grades, for example in tissue production, practically impossible. Pulp is typically available in the form of a pulp bale, which consists of stacked pulp mats. Compared to fluff pulp material, pulp bales offer a significant cost advantage. However, pulp bales or pulp materials in general that are not supplied as rolls with defined dimensions and a defined density cannot be directly processed into the required continuous mass flow of defibrated pulp material. In addition to defibration, further processing steps are necessary, e.g.cleaning and / or sorting, which can also disrupt a continuous flow of shredded pulp material.

[0006] It is an object of the present invention to provide a method and an apparatus for producing an airlaid product or a nonwoven fabric which has a higher economic efficiency and more flexible applicability.

[0007] The object is achieved by a method having the features of claim 1 and a device having the features of claim 16.

[0008] In the method according to the invention for producing an airlaid product or a nonwoven fabric from a starting material, in particular from a cellulose material in the form of a bundle, such as a cellulose bale, the starting material is reduced to a comminuted material in at least one reduction line by means of at least one reduction device, and the comminuted material is fed to at least one material buffer. From the at least one material buffer, the comminuted material is removed in a metered manner by means of at least one metering device and fed to at least one processing line with at least one defibration system, in which the comminuted material is defibrated to a defibrated material. The defibrated material is fed to a production machine and processed into an airlaid product or a nonwoven fabric.The at least one dosing device is controlled in such a way that a continuous mass flow of shredded material is fed to the production machine.

[0009] A device for producing an airlaid product or a nonwoven fabric from at least one starting material, in particular from a cellulose material in the form of a bundle, such as a cellulose bale, comprises at least one comminution line with at least one comminution device for comminuting the at least one starting material into at least one comminuted material. Furthermore, the device comprises at least one material buffer for receiving a comminuted material assigned to the material buffer, wherein the at least one material buffer has at least one controllable metering device for metered removal of the assigned comminuted material from the at least one material buffer and for feeding the at least one comminuted material to at least one processing line.The at least one processing line comprises at least one defibration system designed to defiber the at least one shredded material into at least one defibrated material. The device further comprises a manufacturing machine for producing an airlaid product or a nonwoven fabric from the at least one defibrated material, wherein a control unit is provided which is configured and designed to control the at least one metering device such that a continuous mass flow of defibrated material is supplied to the manufacturing machine. A manufacturing method according to the invention can be carried out using the device according to the invention.

[0010] According to the invention, a starting material, prior to fiberization, is first reduced to a comminuted material by means of a comminution device in a first process step and then introduced into a material buffer, for example, a bunker, in which the comminuted material is temporarily stored. From the material buffer, the comminuted material is fed to the fiberization and production machine in a second process step.

[0011] The first process step, preceding the fiberization, from the comminution of the starting material to the feeding of the shredded material to the material buffer, makes the inventive manufacturing process for nonwovens or airlaid products independent of the use of cost-intensive fluff pulp material in roll form and instead allows the use of starting materials in any commercially available containers. For example, pulp bales can be used. In addition to cost savings, this also allows energy savings, since the low density of fluff pulp material requires a higher proportion of thermal drying during its production compared to conventional pulp materials such as pulp bales. In In a comparable manner, these advantages are achieved by the device according to the invention, in particular by providing at least one comminution line and at least one material buffer with at least one dosing device.

[0012] The pulp bales used are composed of several individual, stable, compacted pulp material sheets, which are stacked and bundled into a single bale. These pulp bales differ from the commonly used cotton bales in that they fall apart very easily and require only a small fraction of the fiberization.

[0013] The cellulose material boards used typically have a basis weight of greater than or equal to 400 g / m 3 , in particular greater than or equal to 600 g / m 2 , and preferably less than or equal to 1200 g / m 3 . The boards are very stable and require shredding equipment adapted to these properties.

[0014] The process and device can be used not only for pulp materials, but generally for any raw material that can be dry-fibered, regardless of the packaging form. The raw material can be introduced into the process or device in loose, lightly compressed, or even in roll form. For example, waste paper and / or production waste can be processed in the manner described.

[0015] Airlaid products can include dry-laid products from the group of tissue webs, wipes, towels, napkins, tablecloths, paper webs, writing and printing paper, etc. Nonwovens can include dry-laid products from the group of wipes, towels, napkins, tablecloths, etc. The products mentioned in the groups are merely examples and do not represent an exhaustive list.

[0016] In a first process step, the starting material is reduced to a comminuted material with a certain maximum piece size, which is in particular stackable and meterable and is stacked in a material buffer or temporarily stored in another form. The material buffer, for example a bunker, is advantageously designed or dimensioned such that the process steps preceding the stacking or temporary storage of the comminuted material can be carried out independently of the process steps following the stacking or temporary storage of the comminuted material. This enables batch operation in the comminution line or in the first process section, in which, in particular, a supply of comminuted material is created in the material buffer.

[0017] In the second process step following stacking or intermediate storage, the shredded material is defibred and fed to the typically continuously operating production machine. A continuous, in particular temporally constant, mass flow of shredded material is therefore required to obtain a uniform airlaid product or a uniform nonwoven fabric. According to the invention, the provision of a continuous mass flow of shredded material is made possible by metering the discharge of the shredded material from the at least one material buffer by means of the at least one metering device, in particular in a controlled or regulated manner. The at least one metering device can specifically feed a defined amount of shredded material to a processing line per unit of time.

[0018] Advantageous embodiments of the invention can be found in the dependent claims, the description and the drawings.

[0019] According to a preferred embodiment, all steps of the process for producing a nonwoven or airlaid product are carried out on a continuous production line. All components of a device for producing an airlaid product or a nonwoven can thus be combined in a common production line. In this case, the transport of intermediate material products away from the continuous production line or the production of additional intermediate products on further processing lines located outside the continuous production line is not provided for.

[0020] The dosing device can be controlled, in particular by the control unit, based on a characteristic parameter of the mass flow of shredded material detected by a sensor system. The mass flow of shredded material is particularly relevant with regard to the airlaid material or nonwoven fabric being produced, since it directly corresponds to the amount of material fed to the production machine and to be processed therein. For example, the at least one processing line in or downstream of the shredding system can have a sensor device which determines the mass flow of the shredded material before it is fed to the production machine, in particular optically. Based on the determined mass flow of shredded material, the amount of shredded material discharged from the material buffer by the dosing device can be adjusted in order to generate the desired mass flow of shredded material.

[0021] According to a further embodiment, the dosing device is controlled, in particular by the control device, based on a characteristic parameter of the manufactured airlaid product or nonwoven fabric, which parameter is detected by a sensor system, in particular wherein the parameter is a basis weight. In this case, the amount of comminuted material discharged is controlled directly based on a property of the manufactured airlaid product or nonwoven fabric, thereby purposefully improving its quality or homogeneity.

[0022] The dosing device can also be controlled in such a way that a continuous mass flow of shredded material is fed to a processing line assigned to the dosing device. If, with this approach and the design of the production plant, it can be assumed that the continuous mass flow fed to the processing line also leads – almost "automatically" – to a continuous mass flow for the production machine, additional complex sensor or control technology may be dispensed with, since only appropriate control of the dosing device is required.

[0023] In particular, for the production of a multi-layer product with at least two layers of an airlaid product or nonwoven fabric, the shredded material can be removed in a metered manner from a material buffer assigned to the at least two metering devices by means of at least two metering devices and fed to at least two processing lines, each with a fiberization system, in which the shredded material is fiberized into the fiberized material. Each of the at least two metering devices can be assigned to one of the at least two processing lines. The fiberized material from the at least two processing lines can be fed to the same production machine and processed therein into a, in particular multi-layer, airlaid product or nonwoven fabric. In principle, more than two metering devices can also be assigned to a material buffer, wherein each metering device of the material buffer is provided for feeding a processing line.A processing line can, for example, be used to process the material of a product layer for an airlaid product or a nonwoven fabric to be manufactured.

[0024] If present, at least two dosing devices of a material buffer can be controlled independently of one another. Thus, at least two different processing lines, each assigned to one of the at least two dosing devices, can be independently supplied with defined quantities of shredded material from the material buffer, in particular with different quantities. For example, different product layers of an airlaid product or nonwoven fabric can be produced in this way.

[0025] At least two different starting materials, in particular pulp materials, can be used in the process and / or device. For example, depending on the product requirements and the requirements of the production machine, long-fiber pulp, short-fiber pulp, scrap material, and / or other starting materials can be used. The at least two different starting materials can be introduced into the process or device in separate, material-specific containers or in containers already containing a material mixture.

[0026] According to one embodiment, the at least two different starting materials are comminuted by means of the same comminution line or comminution device, in particular separately, into at least two different comminuted materials. The comminution of the at least two different starting materials can, for example, be carried out successively by means of the same comminution device.

[0027] According to a further embodiment, the at least two different starting materials are shredded into at least two different shredded materials by means of at least two shredding lines or shredding devices. For this purpose, a device or production line for manufacturing a nonwoven fabric or airlaid product can have two different shredding devices or shredding lines. These can have different specifications, each of which is particularly suitable for specific starting materials. This ensures a high shredding quality of the at least two different shredded materials.

[0028] Each of the at least two different shredded materials can be fed into a separate material buffer. The different shredded materials can be stored or stacked separately in their own material buffers and can be retrieved separately from them.

[0029] According to one embodiment, a defined material composition comprising at least two mutually different comminuted materials from at least two material buffers can be supplied to each processing line by means of dosing devices assigned to these, respectively. The at least two mutually different comminuted materials can be fiberized together by the fiberization system of the processing line, wherein the at least two comminuted materials are mixed to form a homogeneous fiberized material. Different comminuted materials from different material buffers can be freely mixed together in any desired proportions by controlling the dosing devices of the material buffers accordingly, in particular by means of the control unit.

[0030] In principle, any number of shredding lines comprising a shredding device, any number of material buffers, and any number of processing lines with defibration systems can be combined independently of one another to create a desired device or production line. This provides an extremely flexible manufacturing process that can be adapted to numerous product requirements and configured according to the required production volume, the pulp material used, and the capacity of the individual machines. If a multi-layer product is manufactured, the flexibility of the process also allows for different material compositions for the individual product layers.

[0031] The at least one starting material can be comminuted and / or defibrated by means of the at least one comminution device in an at least substantially dry state, in particular without the addition of water or solvent. In particular, it can be provided that the moisture content of the starting material, the comminuted 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.

[0032] According to one embodiment, the at least one shredded material is sorted with respect to a characteristic parameter, in particular by means of a sieve and / or a cyclone separator. Alternatively or additionally, the at least one shredded material can be sorted with respect to a characteristic parameter, in particular by means of a sieve and / or a cyclone separator. The characteristic parameter can be, for example, a piece size of the shredded or shredded material, with material that exceeds a maximum piece size being sorted out and, if necessary, fed back into the shredding or shredding process. This ensures a high level of homogeneity of the shredded and / or shredded material, which has a positive effect on the subsequent process steps and ultimately on the quality of the manufactured nonwoven fabric or airlaid product.

[0033] According to a further embodiment, the at least one comminuted material is cleaned, in particular by means of a cyclone separator and / or a magnetic separator. Alternatively or additionally, the at least one fiberized material can be cleaned, in particular by means of a cyclone separator and / or a magnetic separator. In this process, impurities, such as metallic foreign matter, and / or heavy particles can be removed from the comminuted and / or fiberized material to obtain a clean and homogeneous comminuted and / or fiberized material.

[0034] According to a further embodiment, a material buffer is suitable for receiving at least one, preferably two, supplied bundles of pulp material, 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, bridging the changeover times during the discontinuous bale feed. The buffer size is crucial for the continuous operation of the downstream production machine.

[0035] According to a further embodiment, a material buffer is arranged downstream of a pulp material comminution device and upstream of a fiberization system in such a way that buffering upstream of the fiberization system and continuous operation of the fiberization system, preferably a hammer mill, is enabled. This is advantageous for the service life of the fiberization systems used, preferably hammer mills, which experience less wear with continuous feeding, and also for continuous quality, since differences in the first and last fiberized pulp materials can occur during discontinuous operation.

[0036] According to a further embodiment, the cellulose material used has a basis weight of greater than or equal to 400 g / m 3 , in particular greater than or equal to 600 g / m 2 , preferably less than or equal to 1200 g / m 3 . This advantageously allows the necessary quantities of starting material to be stored in a space-saving manner. However, the high basis weight also places special demands on the shredding devices used.

[0037] According to a further embodiment, the manufacturing machine of an airlaid product or a nonwoven fabric is a paper and / or tissue machine.

[0038] According to another embodiment, the starting material is provided solely in the form of pulp bales. Advantageously, no expensive roll material is used.

[0039] Preferred embodiments of the invention are explained below purely by way of example with reference to the accompanying drawings. They show: Fig. 1 shows a schematic representation of a manufacturing device for a nonwoven fabric or an airlaid product from fluff pulp material according to the prior art; Fig. 2 shows a schematic representation of a manufacturing device according to the invention for a nonwoven fabric or an airlaid product from a bale-shaped starting material, with a comminution line, at least one material buffer, and at least one processing line with a defibration system; Fig. 3 shows a schematic representation of a manufacturing device according to the invention for a three-layer nonwoven fabric or a three-layer airlaid product from bale-shaped starting materials, with two comminution lines, three material buffers, and three processing lines, each with a defibration system.

[0040] Fig. 1 shows a schematic representation of a device 10 according to the prior art for producing an airlaid product or a nonwoven fabric 16 from fluff pulp material, which is provided in the form of a fluff pulp material web 14 wound into 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 with a defibrillation system 18, in which the fluff pulp material web 14 is defibrated. The defibrated pulp material is then fed to a production machine 20, in which an airlaid product or a nonwoven fabric 16 is manufactured therefrom.

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

[0042] Optionally, the manufacturing machine 20 can be fed with additional materials, which in Fig. 1 to emphasize its optional nature, it is shown in dashed lines. On the one hand, one or more already fully processed materials 26 can be fed to the production machine 20 together with the pulp material defibrated by the defibration system 18. On the other hand, the device 10 can comprise a second processing line 28, on 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 created. This can also be fed to the production machine 20, wherein in the second processing line 28, too, a control 38 of the web speed can take place as described above by means of a second sensor device 36.

[0043] The device 10 according to the prior art requires the use of fluff pulp material webs 14, 32 in the form of defined unwindable material rolls 12, 30, since this is the only way to ensure that a continuous mass flow of fluff pulp material is fed to the production machine 20.

[0044] In contrast, a device according to the invention is designed and configured so that a starting material can be used in any container shape. Fig. 2 shows a device 40 for producing an airlaid product or a nonwoven fabric 16 from at least one starting material 42. Essential components of the device 40 are shown by solid lines, optional components by dashed lines.

[0045] According to Fig. 2 All parts or components of the device 40 are arranged in a continuous, common production line in which a method for producing an airlaid product or nonwoven fabric 16 can be carried out. In the following, the basic functioning of the device 40 and a manufacturing method that can be carried out with the device 40 will be explained first based on the basic device components and method steps.

[0046] The starting material is Fig. 2 A pulp material in the form of a pulp bale 45 is provided, wherein the pulp bale 45 is formed by stacked pulp mats (not shown). In principle, a starting material 42 in the form of any desired bundle can be used. First, the starting material 42, for example the entire pulp bale 45 or a portion thereof, is fed to a comminution line 46 of the device 40, which comprises a comminution device 48, by means of which the starting material 42 is comminuted into a comminuted material. It is provided that the starting material 42 is comminuted dry without the addition of water.

[0047] The comminution device 48 can, for example, comprise a single-shaft or multi-shaft comminutor. It can be equipped with a sieve that defines a maximum particle size of the comminuted material discharged from the comminution device 48, thus at least partially homogenizing and metering it. The comminution material can be discharged from the comminution device 48, for example, by means of a conveyor belt, a screw conveyor, or a suction box. Preferably, the discharge is carried out using a suction box or a screw conveyor with assisted suction. The suction prevents the accumulation of dust in the area of the comminution device 48. Furthermore, rapid discharge of the comminution material, assisted by suction, positively influences the comminution quality.

[0048] The device 40 comprises a material buffer 50, for example, a hopper, which is designed to receive the shredded material. To supply the shredded material to the material buffer 50, it can be discharged from the discharge of the shredding device 48 into an air duct and transported toward the material buffer 50 by means of an air stream. The air stream can be generated by a transport fan with an open impeller, which is arranged downstream of the shredding device in the material stream of the shredded material. Alternatively or additionally, a more energy-efficient transport fan with a closed impeller can be provided.

[0049] This can, in particular, be located downstream of the material buffer 50, where the shredded material has already been separated from the air stream and stacked in the material buffer 50 or temporarily stored in another form. A dedicated cyclone separator and / or a sieve separator can be provided to separate the shredded material from the air stream and / or to temporarily store the shredded material in the material buffer 50.

[0050] The material buffer 50 can be dimensioned such that it can accommodate a larger quantity of shredded material than can be fed to the shredding device 48 at one time. Thus, the material buffer 50 enables batch operation in the shredding line 46, i.e., a series of containers of the starting material 42, for example, several cellulose bales 45, can be shredded by the shredding device 48 into shredded material, which is then fed to the material buffer 50 and, if necessary, temporarily stored therein. In this respect, a first process section 52, from the shredding of the starting material 42 to the temporary storage of the shredded material in the material buffer 50, can be carried out independently of subsequent production steps. This is Fig. 2 indicated by a dash-dotted line, above which the first process section 52 (batch operation) is shown.

[0051] A second process section 53 (continuous or quasi-continuous operation) begins with the removal of the shredded material from the material buffer 50 ( Fig. 2 , below the dotted line). For this purpose, the material buffer 50 has a controllable dosing device 54, by means of which the shredded material can be removed from the material buffer 50 in a metered manner. The dosing device 54 feeds the shredded material to a processing line 56. The controllable dosing device 54 can be designed as a speed-controlled screw conveyor, which discharges and doses the shredded material stacked in the material buffer 50 and supplies the processing line 56 with a controlled mass flow of shredded material.

[0052] The processing line 56 comprises a fiberizing system 58, by means of which the shredded material is fiberized into a fiberized material. The resulting fiberized material is then fed to a production machine 60 of the device 40, in which an airlaid product or nonwoven fabric 16 is produced from it. The fiberizing system 58 can be fed using a conveyor belt, a screw conveyor, or with the aid of an air stream. According to an advantageous embodiment, the shredded material is fed by the controllable dosing device 54 directly into a channel assigned to the processing line 56 and fed to the fiberizing system 58 by means of an air stream generated by a transport fan. With this type of feeding, the material buffer 50 and the fiberizing system 58 can be positioned spatially independently of one another and flexibly connected via the channel of the processing line 56.In addition, a change in the dosage of the shredded material fed to the processing line 56, made by the dosing device 54, becomes effective with very little time delay in the defibration system 58 and thus ultimately also in the manufacturing machine 60 due to the high transport speed of the air flow, so that a particularly direct control of the production process is possible, which ultimately has a positive effect on the quality of the airlaid product or nonwoven fabric 16 produced.

[0053] The defibration system 58 is configured to defiber the comminuted material in a substantially dry state without the addition of water. The defibration system 58 may comprise at least a first hammer mill, which defibers the comminuted material. To achieve improved defibration quality, the defibration system 58 may additionally comprise a second hammer mill downstream of the first hammer mill. The first hammer mill may be provided with a screen to prevent entire, unfibered pieces of comminuted material from leaving the first hammer mill and entering the second hammer mill. The second hammer mill may have narrower and more tightly fitting hammers than the first hammer mill and remove any knots present in the material defibered by the first hammer mill, which ultimately has a positive effect on the quality of the produced airlaid product or nonwoven fabric 16.

[0054] The dry-fibered pulp material is then fed to the production machine 60, for example, via a duct system connected to the fiberization system 58 by means of an air flow generated by a transport fan. The production machine 60 can be a conventional continuously operating production machine 60, so that a continuous mass flow of fiberized material must be fed to it 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 such that a continuous mass flow of fiberized material is fed to the production machine 60. For this purpose, the device 40 has a control unit 62, which is designed and configured to control the controllable metering device 54 accordingly.

[0055] The control of the dosing device 54 is carried out according to Fig. 2 based on a characteristic parameter of the mass flow of shredded material between the shredding system 58 and the production machine 60. To determine the mass flow of shredded material, a sensor device 64 is mounted directly behind the shredding system 58, for example in the duct system, or possibly also behind the cleaning device 70 and / or behind a sorting device 72, which detects the actual mass flow, for example by means of a camera system or other suitable sensors. The actually detected mass flow serves as a controlled variable for the controllable dosing device 54. If it deviates from a target mass flow, the dosing device 54 is controlled or readjusted (control 55) in order to achieve this target mass flow.

[0056] Alternatively, the dosing device 54 can be controlled based on a characteristic parameter of the manufactured airlaid product or nonwoven fabric 16, for example, based on an actual basis weight of the airlaid product or nonwoven fabric 16, detected by suitable sensors. If the actually detected basis weight deviates from a target basis weight, the dosing device is controlled or adjusted accordingly in order to feed an adjusted amount of shredded material to the processing line and thus achieve the target basis weight. In principle, the dosing device 54 can be controlled such that a continuous and, in particular, constant, i.e., temporally unchanged, mass flow of shredded material is fed to the processing line 56.

[0057] In Fig. 2 Further, optionally provided, components of the device 40 are shown in dashed lines. The comminution line 46 can comprise a cleaning device 66, which is arranged downstream of the comminution device 48 and, for example, in a channel system for transporting the comminuted material. The cleaning device 66 can comprise a magnetic separator that frees the comminuted material of metallic foreign matter. The cleaning device 66 can be followed by a sorting device 68, which, for example, comprises a cyclone separator that removes heavy particles before the comminuted, cleaned, and sorted material is fed to the material buffer 50.

[0058] In a similar manner, alternatively or additionally, a cleaning device 70 and / or a sorting device 72 can be arranged in the processing line 56 downstream of the defibration system 58 to clean the defibrated material of foreign and impurities and to sort it, for example, according to its piece size. A magnetic separator, a cyclone separator, and / or a screen separator can be used for this purpose.

[0059] In addition, the device 40 can have a feed 74 for additional, already fully processed materials upstream of the production machine 60. Furthermore, the device 40 can have a second processing line 56.2, which can be fed with comminuted material by means of a controllable second dosing device 54.2 of the material buffer 50. Thus, each processing line 56, 56.2 is assigned a separate, controllable dosing device 54, 54.2, through which the processing lines 56, 56.2 are fed with comminuted material from the material buffer 50. Conversely, the material buffer 50 has a separate dosing device 54, 54.2 for each processing line 56, 56.2. The dosing devices 54, 54.2 can be controlled independently of one another, so that a separately definable quantity of shredded material from the material buffer 50 can be fed to each processing line 56, 56.2.

[0060] Analogous to the processing line 56, the second processing line 56.2 comprises a second defibration system 58.2 for defibrating shredded material. Furthermore, a second cleaning device 70.2 and a second sorting device 72.2 can be provided in the second processing line 56.2, as described above in connection with the first processing line 56. In the second processing line 56.2, a second sensor device 64.2 is arranged directly behind the second defibration system 58.2 or behind the second cleaning device 70.2 or the second sorting device 72.2, which detects the mass flow of defibrated material. Should the actually measured mass flow deviate from a target mass flow defined for the second processing line 56.2, the second dosing device 54.2 assigned to the second processing line 56.2 is readjusted or controlled (control 55.2) on this basis in order to achieve the target mass flow.

[0061] During the production of a multi-layer airlaid product or nonwoven fabric 16, each of the processing lines 56, 56.2 can be provided to shred the starting material 42 for one product layer and feed it to the production machine 60. Each processing line 56, 56.2 can be supplied with the appropriate amount of shredded starting material for this purpose by means of the dosing device 54, 54.2 assigned to it.

[0062] To produce an airlaid product or nonwoven fabric 16, various materials can be used, in particular, in addition to the starting material 42, a second starting material 43 and a third material 44. For example, long-fiber pulp can be used as the starting material 42, short-fiber pulp as the second starting material 43, each in bale form, and an already shredded scrap material can be used as the third starting material 44 ( Fig. 2 , top right). The device 40 can have a separate material buffer 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, possibly pre-processed, scrap material 44.

[0063] Since long-fiber and short-fiber pulp bales behave similarly during shredding, they can be shredded using the same shredding device 48 in the shredding line 46 and optionally cleaned and sorted using the same cleaning device 66, in particular the same magnetic separator, and the same sorting device 68, in particular the same cyclone separator. The shredding, cleaning, and sorting of the starting materials 42, 43 takes place separately, e.g., one after the other, so that the resulting shredded material only comprises one type of material. In order to deposit each of the various shredded materials in the material buffer 50, 76 assigned to it, a channel system of the shredding line 46 can be switched such that shredded material from long-fiber pulp 42 is fed to the bunker 50 and shredded material from short-fiber pulp 43 is fed to the bunker 76.The already shredded scrap material 44 is fed to the third material hopper 78. For stacking the respective material 42, 43, 44, each material hopper 50, 76, 78 preferably has a cyclone separator and / or a sieve separator.

[0064] The second and third material buffers 76, 78 can also each have two dosing devices 80, 80.2 and 82, 82.2, respectively, which are each assigned to one of the processing lines 56, 56.2 and can be controlled independently of one another. Via the control unit 62, each of the two processing lines 56, 56.2 can thus be fed independently of one another with a defined material composition of shredded material with arbitrarily selectable proportions of long-fiber pulp 42, short-fiber pulp 43 and reject material 44. All shredded materials fed to a respective processing line 56, 56.2 are shredded together in the shredding system 58, 58.2 arranged in the corresponding processing line 56, 56.2 and are thereby mixed. In this way, a multi-layer, according to Fig. 2 two-layer, airlaid product or nonwoven product 16 with different material compositions of the individual product layers.

[0065] Using the sensor devices 64, 64.2 of the two processing lines 56, 56.2, the mass flow in the respective processing line 56, 56.2 can be detected, as already described above for the dosing devices 54, 54.2 of the material buffer 50. Based on the data detected by the sensor device 64, the dosing devices 54, 80, 82 assigned to the processing line 56 are readjusted or controlled (control 55, 81, 83). Based on the data detected by the second sensor device 64.2, the dosing devices 54.2, 80.2, 82.2 assigned to the second processing line 56.2 are readjusted or controlled (control 55.2, 81.2, 83.2).

[0066] Fig. 3 shows a further device 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 device 40 in bale form. As in connection with Fig. 2 As described, this can be, for example, long-fiber pulp 42, short-fiber pulp 43, and reject material 44. In order to shred the starting materials 42, 43, 44, the device 40 has a first shredding line 46.1 for the long-fiber and short-fiber pulp materials 42, 43 (cf. Fig. 2 ) and a second comminution line 46.2 for the reject material 44, each comprising a comminution device 48.1, 48.2, a cleaning device 66.1, 66.2, and a sorting device 68.1, 68.2. For the reject material 44, a separate comminution device 48.2 as well as a separate magnetic separator and cyclone separator for cleaning and sorting are advantageously used, as this allows adaptation to the requirements of the reject material 44 with regard to shape, material properties, and production quantity. This allows the long-fiber and short-fiber pulp materials 42, 43 to be comminuted independently of the reject material 44, the comminution quality can be improved for all starting materials 42, 43, 44, and due to the typically smaller amount of reject material used, smaller machines can be used in the second comminution line 46.2, thus saving energy.

[0067] Each of the three shredded starting materials 42, 43, 44 is fed to a separate material buffer 50, 76, 78. To produce the three product layers, each of which has an individual material composition, the device has a first, a second, and a third processing line 56.1, 56.2, 56.3. Each of the material buffers 50, 76, 78 therefore has three independently controllable dosing devices, each of which has a first dosing device 54.1, 80.1, 82.1 for feeding the first processing line 56.1, a second dosing device 54.2, 80.2, 82.2 for feeding the second processing line 56.2, and a third dosing device 54.3, 80.3, 82.3 for feeding the third processing line 56.3. By means of a fiberization system 58.1, 58.2, 58.3 for each processing line 56.1, 56.2, 56.3, the shredded material fed to it is shredded and homogeneously mixed, and then fed to a manufacturing machine 60 for producing a three-layer airlaid product or nonwoven fabric 16.

[0068] Each of the three processing lines 56.1, 56.2, 56.3 has its own sensor device 64.1, 64.2, 64.3, which, as in connection with Fig. 2 described above, is arranged between the respective comminution system 58.1, 58.2, 58.3 and the production machine 60 and records the mass flow of shredded material in the respective processing line 56.1, 56.2, 56.3. A comparison of the mass flow actually recorded in each processing line 56.1, 56.2, 56.3 with a target mass flow serves as a basis for controlling each of the first dosing devices 54.1, 80.1, 82.1, second dosing devices 54.2, 80.2, 82.2 and / or third dosing devices 54.3, 80.3, 82.3, if necessary, such that the target mass flow is achieved and a correspondingly continuous, in particular temporally constant, mass flow is supplied to the production machine 60.

[0069] From the above, it is clear that the inventive concept can be easily adapted to the respective requirement profile. The three processing lines 56.1, 56.2, 56.3 and thus the three layers of the airlaid product or nonwoven fabric 16 can be independently composed of the three materials 42, 43, 44, respectively. Bezugszeichenliste

[0070] 10Device according to the prior art 11Preparation line 12Material roll 14Fluff pulp material web 16Airlaid product or nonwoven fabric 18Defibration system 20Production machine 22Sensor device 24Control of the web speed of the first preparation line 26Feed of finished processed materials 28Second preparation line 30Second material roll 32Second fluff pulp material web 34Second defibration system 36Second sensor device 38Control of the web speed of the second preparation line 40Device for producing an airlaid product or a nonwoven fabric 42Starting material 43Second starting material 44Third starting material 45Cellulum bale 46Cutting line 46.1First cutting line 46.2Second cutting line 48Cutting device 48.1First shredding device 48.2 Second shredding device 50 Material buffer 52 First process section 53 Second process section 54 Controllable dosing device of the material buffer 54.1 First controllable dosing device of the material buffer 54.2 Second controllable dosing device of the material buffer 54.3 Third controllable dosing device of the material buffer 55 Control of the dosing device of the material buffer 55.2 Control of the second dosing device of the material buffer 56 Processing line 56.1 First processing line 56.2 Second processing line 56.3 Third processing line 58 Fiberization system 58.1 First fiberization system 58.2 Second fiberization system 58.3 Third fiberization system 60 Production machine 62 Control unit 64 Sensor device 64.1 First sensor device 64.2 Second sensor device 64.3Third sensor device 66Cleaning device for shredded material 66.1Cleaning device for shredded material of the first shredding line 66.2Cleaning device for shredded material of the second shredding line 68Sorting device for shredded material 68.1Sorting device for shredded material of the first shredding line 68.2Sorting device for shredded material of the second shredding line 70Cleaning device for shredded material 70.2Second cleaning device for shredded material 72Sorting device for shredded material 72.2Second sorting device for shredded material 74Supply of further materials 76Second material buffer 78Third material buffer 80Controllable dosing device of the second material buffer 80.1First controllable dosing device of the second material buffer 80.2Second controllable dosing device of the second material buffer 80.3Third controllable dosing device of the second material buffer 81Control of the dosing device of the second material buffer 81.2Control of the second dosing device of the second material buffer 82Controllable dosing device of the third material buffer 82.1First controllable dosing device of the third material buffer 82.2Second controllable dosing device of the third material buffer 82.3Third controllable dosing device of the third material buffer 83Control of the dosing device of the third material buffer 83.2Control of the second dosing device of the third material buffer.

Claims

1. Method for producing an airlaid product or a nonwoven fabric (16) from a starting material (42), in particular from a pulp material in the form of a bundle, for example a pulp bale (45), in which the starting material (42) is shredded in at least one shredding line (46, 46.1, 46.2) by at least one shredding device (48, 48.1, 48.2) to produce a shredded material, the shredded material is fed to at least one material buffer (50, 76, 78), the shredded material is removed from the at least one material buffer (50, 76, 78) in a metered manner by 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) and fed to at least one preparation line (56, 56.1, 56.2, 56.3) having at least one defibration system (58, 58.1, 58.2, 58.2), in which the shredded material is defibrated to produce a defibrated material, the defibrated material is fed to a production machine (60) and processed to produce an airlaid product or a nonwoven fabric (16), characterized in that 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) is controlled in such a way that a continuous mass flow of defibrated material is fed to the production machine (60).

2. Method according to at least Claim 1, wherein all steps of the method are carried out on a continuous production line.

3. Method according to Claim 1 or 2, wherein the metering device is controlled on the basis of a parameter of the mass flow of defibrated material recorded by a sensor system (64, 64.1, 64.2, 64.3).

4. Method according to at least one of the preceding claims, wherein the metering device is controlled on the basis of a characteristic parameter of the produced airlaid product or nonwoven fabric (16) recorded by a sensor system, in particular wherein the parameter is a basis weight.

5. Method according to at least one of the preceding claims, wherein the metering device is controlled in such a way that a continuous mass flow of shredded material is fed to a preparation line (56, 56.1, 56.2, 56.3) associated with the metering device.

6. Method according to at least one of the preceding claims, wherein, in particular, to produce a multilayer product comprising at least two layers of an airlaid product or nonwoven fabric (16), the shredded material is removed from a material buffer (50, 76, 78) associated with at least two metering devices in a metered manner by the at least two metering devices and fed to at least two preparation lines (56, 56.1, 56.2, 56.3), each having a defibration system (58, 58.1, 58.2, 58.3), in which the shredded material is defibrated in each case to produce the defibrated material, wherein each of the at least two metering devices is associated with one of the at least two preparation lines (56, 56.1, 56.2, 56.3), and wherein the defibrated material of the at least two preparation lines (56, 56.1, 56.2, 56.3) is fed to the same production machine (60) and is processed therein to produce an airlaid product or nonwoven fabric (16), in particular a multilayer airlaid product or nonwoven fabric.

7. Method according to Claim 6, wherein at least two metering devices of a material buffer (50, 76, 78) are controlled independently of one another.

8. Method according to at least one of the preceding claims, wherein at least two mutually different starting materials (42, 43, 44), in particular pulp materials, are used.

9. Method according to Claim 8, wherein the at least two mutually different starting materials (42, 43, 44) are shredded by the same shredding line (46) or shredding device (48), in particular separately, to produce at least two mutually different shredded materials.

10. Method according to at least Claim 8, wherein the at least two mutually different starting materials (42, 43, 44) are shredded by at least two shredding lines (46.1, 46.2) or shredding devices (48.1, 48.2) to produce two mutually different shredded materials.

11. Method according to at least Claim 9 or 10, wherein each of the at least two mutually different shredded materials are fed to a separate material buffer (50, 76, 78).

12. Method according to at least one of the preceding claims, wherein each preparation line (56, 56.1, 56.2, 56.3) may be supplied with a defined material composition consisting of at least two mutually different shredded materials from at least two material buffers (50, 76, 78) by metering devices respectively associated therewith.

13. Method according to at least one of the preceding claims, wherein the at least one starting material (42, 43, 44) is shredded and / or defibrated at least substantially dry by the at least one shredding device (48, 48.1, 48.2), in particular without the addition of water or solvent.

14. Method according to at least one of the preceding claims, wherein the at least one shredded material is sorted according to a characteristic parameter, in particular using a screen and / or a cyclone separator (68, 68.1, 68.2), and / or wherein the at least one defibrated material is sorted according to a characteristic parameter, in particular using a screen and / or a cyclone separator (72, 72.2).

15. Method according to at least one of the preceding claims, wherein the at least one shredded material is cleaned, in particular using a cyclone separator and / or a magnetic separator (66, 66.1, 66.2), and / or wherein the at least one defibrated material is cleaned, in particular using a cyclone separator and / or a magnetic separator (70, 70.2).

16. Device (40) for producing 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, for example a pulp bale (45), comprising at least one shredding line (46, 46.1, 46.2) having at least one shredding device (48, 48.1, 48.2) for shredding the at least one starting material (42, 43, 44) to produce at least one shredded material, at least one material buffer (50, 76, 78) for receiving a material respectively associated with the material buffer (50, 76, 78), wherein the at least one material buffer (50, 76, 78) 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) in each case for the metered removal of the respectively associated shredded material from the at least one material buffer (50, 76, 78) and for feeding the at least one shredded material to at least one preparation line (56, 56.1, 56.2, 56.3), wherein the at least one preparation line (56, 56.1, 56.2, 56.3) comprises at least one defibration system (58, 58.1, 58.2, 58.2), which is designed to defibrate the at least one shredded material to produce at least one defibrated material, and a production machine (60) for producing an airlaid product or a nonwoven fabric (16) from the at least one defibrated material, characterized in that a control unit (62) is provided, which is configured and designed to control the at least one metering device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 80, 82.1, 82.2, 82.3) in such a way that a continuous mass flow of defibrated material is fed to the production machine (60), in particular according to a method according to at least one of claims 1 to 15.

17. Device according to Claim 16, wherein all components of the device are arranged in a common production line.

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