EP4367322A1

EP4367322A1 - Method for producing airlaid products

Info

Publication number: EP4367322A1
Application number: EP22738484.9A
Authority: EP
Inventors: Thomas EHL; Jonas BERGSTRÖM
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2021-07-08
Filing date: 2022-07-05
Publication date: 2024-05-15
Also published as: CN117642540A; US20240141568A1; WO2023280812A1

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

Manufacturing process for airlaid products

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.

Such methods and devices are known in principle. Typically, fluff cellulosic material known as fluff pulp is used. The fluff cellulose material is delivered as roll goods, with a fluff cellulose web wound into a roll not only having a defined thickness and a defined width, but also other well-defined properties that enable smooth further processing. The fluff pulp usually has a high degree of purity, a uniform density of, for example, less than 0.65 g/cm ³ and a uniform moisture content, and can be defibrated very easily in the dry state, also known as defibration. This is particularly relevant as the manufacture of nonwovens and dry-laid products, especially airlaid or so-called airlaid products, is usually done without the addition of water or other solvents, ie 'dry'. Fluff cellulose material as rolled goods is characterized by good running properties, low shredding energy required and a low knot content. The fluff cellulose material used is usually already prepared according to the desired material properties and has a desired fiber composition, for example a specific proportion of long and short fibers.

In the manufacture of non-woven products and dry-laid products from fluff pulp material, the roll material is usually unwound at a defined web speed, dry defibration (defibration) and then a non-woven or dry-laid machine (manufacturing machine) fed. There is no need for any further processing of the fluff cellulose material beyond defibration, since the rolls used already have the properties required for further processing. It is characteristic of the known production method that when the fluff cellulose material is unwound from the material roll at a constant web speed, due to the well-defined properties of the fluff cellulose web, a continuous, in particular temporally constant, mass flow of cellulose material is generated, which is also continuously fed to the production machine . The mass flow is adjusted via the web speed during the unwinding of the fluff cellulose material. Finally, the weight per unit area of the fleece or dry-laid product is also set via the mass flow of the material fed to the manufacturing machine.

These special requirements of known production processes and devices for airlaid products or nonwovens on the starting material make it practically impossible to use conventional cellulose materials in commercial containers, as is used with a wide variety of wet-processed paper types, for example in tissue production. Typically, pulp is available in the form of a pulp bale composed of pulp mats stacked on top of one another. Compared to fluff pulp material, pulp bales have a significant cost advantage. However, cellulose bales or cellulose materials in general, which are not supplied as roll goods with defined dimensions and a defined density, cannot be processed directly into the required continuous mass flow of defibrated cellulose material. In addition to defibration, further processing steps are necessary, for example cleaning and/or sorting, which can also disrupt a continuous material flow of defibrated cellulose material. It is an object of the present invention to provide a method and a device for producing an airlaid product or a nonwoven fabric that is more economical and more flexible in use.

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

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 comminuted in at least one comminution line by means of at least one comminution device to form a comminuted material, and that shredded material is fed to at least one material buffer. The comminuted material is removed from the at least one material buffer in a dosed manner by means of at least one dosing device and fed to at least one processing line with at least one defibration system, in which the comminuted material is defibered into a defibrated material. The shredded material is fed to a manufacturing 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 fiberized material is supplied to the production machine.

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 comminuting 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 accommodating a comminuted material assigned to the material buffer, the at least one material buffer in each case at least has a controllable metering device for the metered removal of the respectively 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, which is designed to defiber the at least one comminuted material into at least one defibrated material. The device also includes a manufacturing machine for manufacturing an airlaid product or a nonwoven fabric from the at least one shredded material, a control unit being provided which is set up and configured to control the at least one dosing device in such a way that the manufacturing machine is supplied with a continuous mass flow shredded material is fed. A production method according to the invention can be carried out with the device according to the invention.

According to the invention, a starting material is first comminuted into a comminuted material before defibration by means of a comminuting device and placed in 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 defibration and the manufacturing machine in a second process step.

The first stage of the process, upstream of the defibration, from the comminution of the starting material to the feeding of the comminuted material to the material buffer, makes the production method according to the invention for nonwovens or airlaid products independent of the use of the cost-intensive fluff cellulose material in roll form and instead allows the use of starting materials in any standard packaging. For example, pulp bales can be used. In addition to costs, energy can also be saved as a result of the low density of fluff Pulp material in the production of which a higher proportion of thermal drying is required compared to conventional cellulose material such as cellulose bales. These advantages are achieved in a comparable manner 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.

The cellulose bales used are made up of several individual, stable and compacted cellulose material panels, which are stacked and bundled into a bale. The cellulose bales differ from the cotton bales that are usually very often used in that the cotton bales fall apart very easily and require only a small fraction of defibration.

The sheets of cellulose material used usually have a weight per unit area 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 . The plates are very stable and require shredding equipment adapted to these properties for shredding.

The method and the device can be used not only for cellulose materials, but in general for any starting materials that can be defibrated dry, in particular regardless of the shape of the container. The starting material can, for example, be introduced into the process or the device loosely, lightly pressed, or in roll form. For example, waste paper and/or production rejects can be processed in the manner described.

Airlaid products can include dry-laid products from the group of tissue webs, wipes, towels, serviettes, tablecloths, paper webs, writing and printing paper, etc. Nonwoven fabrics can include dry-laid products from the group of wipes, towels, napkins, tablecloths, etc. the The products of the groups mentioned are only to be understood as examples and do not correspond to a complete list.

In a first method step, the starting material is comminuted into a comminuted material with a certain maximum piece size, which in particular can be stacked and dosed and is stacked in a material buffer or temporarily stored in some other way. The material buffer, for example a bunker, is advantageously designed or dimensioned in such a way that the method steps preceding the stacking or intermediate storage of the comminuted material can be carried out independently of the method steps following the stacking or intermediate storage of the comminuted material. Thus, batch operation in the comminution line or in the first process section is possible, in which in particular a supply of comminuted material is created in the material buffer.

In the second process step following the stacking or intermediate storage, the comminuted material is defibrated (defibrated) and fed to the manufacturing machine, which typically operates continuously. A continuous mass flow of shredded material, in particular one that is constant over time, is therefore required in order 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 in that the shredded material is discharged from the at least one material buffer in a metered manner by means of the at least one metering device, in particular in a controlled or regulated manner. The at least one dosing device can supply a defined quantity of comminuted material to a processing line in a targeted manner per unit of time.

Advantageous developments of the invention can be found in the dependent claims, the description and the drawings. 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. A transport of intermediate material products away from the continuous production line or the manufacture of additional intermediate products on further processing lines arranged outside of the continuous production line is not intended in this case.

The dosing device can be controlled, in particular by the control unit, on the basis of a characteristic parameter of the mass flow of shredded material that is detected using a sensor system. The mass flow of shredded material is particularly relevant in relation to the airlaid material or nonwoven fabric produced, since it directly corresponds to the amount of material to be processed by the production machine and supplied to it. For example, the at least one processing line can have a sensor device in or behind the fiberization system, which determines the mass flow of the fiberized material before it is fed to the production machine, in particular optically. Based on the determined mass flow of shredded material, the quantity 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.

According to a further embodiment, the dosing device is controlled, in particular by the control device, on the basis of a characteristic parameter of the airlaid product or nonwoven produced that is detected using a sensor system, in particular the parameter being a basis weight. In this case, the amount of discharged crushed matter becomes instantaneous based on a property of the manufactured airlaid product or nonwoven fabric, which improves its quality or homogeneity in a targeted manner.

The dosing device can also be controlled in such a way that a continuous mass flow of comminuted material is fed to a processing line assigned to the dosing device. If, with this procedure and the design of the production plant, it can be assumed that the continuous mass flow that is fed to the processing line also - as it were "automatically" - leads to a continuous mass flow for the production machine, then under certain circumstances additional complex sensors or control technology can be used be dispensed with, since only a corresponding control of the dosing device is required.

In particular, for the production of a multi-layer product with at least two layers of an airlaid product or nonwoven fabric, the comminuted material can be removed in metered amounts from a material buffer assigned to the at least two metering devices by means of at least two dosing devices and fed to at least two processing lines, each with a defibration system, in which the comminuted Material is defibrated in each case to the defibrated material. Each of the at least two dosing devices can be assigned to one of the at least two processing lines. The shredded material of the at least two processing lines can be fed to the same manufacturing machine and processed therein to form an airlaid product or non-woven fabric, in particular a multi-layer one. In principle, more than two dosing devices can also be assigned to a material buffer, with each dosing device of the material buffer being provided for feeding a processing line. A processing line can be used, for example, to prepare the material of a product layer for an airlaid product to be produced or a nonwoven fabric to be produced. 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 of which is assigned to one of the at least two dosing devices, can be fed independently of one another with, in particular different, defined amounts of comminuted material from the material buffer. For example, different product layers of an airlaid product or non-woven fabric can be produced in this way.

At least two different starting materials, in particular cellulose materials, can be used in the method and/or in the device. For example, depending on the product requirement 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 method or the device in separate, material-specific containers or in containers that already contain a mixture of materials.

According to one embodiment, the at least two starting materials that are different from one another are comminuted by means of the same comminution line or comminution device, in particular separately, into at least two comminuted materials that are different from one another. The at least two different starting materials can be comminuted, for example, one after the other using the same comminution device.

According to a further embodiment, the at least two different starting materials are comminuted by means of at least two comminution lines or comminution devices to form at least two different comminuted materials. A device or production line for the production of a nonwoven or airlaid product can have two for this purpose have different crushing devices or crushing lines. These can have different specifications, each of which is particularly suitable for certain starting materials. A high comminution quality of the at least two different comminuted materials can thus be ensured.

Each of the at least two different comminuted materials can be supplied to a separate material buffer. The different comminuted materials can be stored or stacked separately from each other in their own material buffers and can be called up separately from there.

According to one embodiment, each processing line can be supplied with a defined material composition of at least two different comminuted materials from at least two material buffers by means of dosing devices assigned to them. The at least two different comminuted materials can be fibrillated together by the fibrillation system of the processing line, with the at least two comminuted materials being mixed to form a homogeneous fibrillated material. Various crushed materials from different material buffers can be freely mixed together in any proportion by controlling the dosing devices of the material buffers accordingly, in particular by means of the control unit.

In principle, any number of comminution lines comprising a comminution device, any number of material buffers and any number of processing lines with defibration systems can be combined independently of one another in such a way that a desired device or production line is created. In this way, an extremely flexible manufacturing process that can be adapted to numerous product requirements is provided can be 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 a different material composition of the individual product layers.

The at least one starting material can be comminuted and/or defibrated at least essentially dry, in particular without the addition of water or solvent, by means of the at least one comminution device. In particular, it can be provided that the moisture content of the starting material, the comminuted material and/or the shredded material does not exceed a value of 10%, in particular a value of 8% or 7%, during the production process.

According to one embodiment, the at least one comminuted material is sorted with regard 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 regard 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 comminuted or defibrated material, with material that exceeds a maximum piece size being sorted out and, if necessary, fed back to the comminution or defibration. This ensures a high degree of homogeneity of the comminuted and/or defibrated material, which has a positive effect on the subsequent process steps and ultimately on the quality of the nonwoven fabric or airlaid product produced.

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 shredded Material are cleaned, in particular by means of a cyclone separator and / or a magnetic separator. In this way, impurities, for example metallic foreign matter, and/or heavy parts can be removed from the comminuted and/or defibrated material in order to obtain a clean and homogeneous comminuted and/or defibrated material.

According to a further embodiment, a material buffer is suitable for accommodating at least one, preferably two, supplied bundles of cellulose material, in particular one, preferably two cellulose bales. Advantageously, the material buffer is designed in such a way that buffering of at least one, preferably two, entire pulp bales is made possible in order to bridge the changeover times when the bales are fed in discontinuously. The buffer size is crucial for continuous operation of the downstream manufacturing machine.

According to a further embodiment, a material buffer is arranged after a shredding device for the cellulose material and before a defibration system in such a way that buffering before the defibration system and continuous operation of the defibration system, preferably a hammer mill, is made possible. This is advantageous for the service life of the defibration systems used, preferably hammer mills, which wear out less with continuous feeding, and also for the continuous quality, since discontinuous operation can show differences in the first and last defibrated pulp materials.

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 . Advantageously, the necessary quantities of starting material can thus be stored in a space-saving manner will. However, the high basis weight also places special demands on the shredding devices used.

According to a further embodiment, the machine for manufacturing an airlaid product or a nonwoven is a paper and/or tissue machine.

According to a further embodiment, the starting material is only provided by pulp bales. Advantageously, no expensive rolled goods are used.

In the following, preferred embodiments of the invention are explained purely by way of example with reference to the attached drawings. Show it:

Fig. 1 is a schematic representation of a manufacturing device for a

nonwoven fabric or an airlaid product made from fluff pulp material according to prior art;

2 shows a schematic representation of an inventive

Production device for a non-woven fabric or an airlaid product from a bale-shaped starting material with a shredding line, at least one material buffer and at least one processing line with a defibration system;

3 shows a schematic representation of an inventive

Manufacturing device for a three-layer nonwoven fabric or a three-layer airlaid product from bale-shaped starting materials with two shredding lines, three material buffers and three processing lines, each with a defibration system. 1 shows a schematic representation of an apparatus 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 cellulose fluff material is unwound from the material roll 12 at a defined web speed and fed to a processing line 11 with a defibration system 18 in which the cellulose fluff material web 14 is defibrated. The defibrated cellulose material is then fed to a manufacturing machine 20 in which an airlaid product or a non-woven fabric 16 is manufactured from it.

Since the cellulose fluff material web 14 has defined dimensions and a uniform density, unwinding the cellulose fluff material web 14 from the material roll 12 at a defined web speed provides a continuous material flow with a constant mass flow of cellulose fluff material in the device 10, which continuously operating manufacturing machine 20 is supplied. The mass flow of fiberized cellulose material can be detected between the fiberization system 18 and the manufacturing 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 set to the target mass flow by adjusting the web speed when unwinding the fluff cellulose material web 14 from the material roll 12 (regulation 24).

Optionally, the manufacturing machine 20 can be loaded with additional materials, which is shown in FIG. 1 with dashed lines to emphasize the optional character. On the one hand, one or more materials 26 that have already been completely processed can be fed to the manufacturing machine 20 together with the pulp material that has been defibrated by the defibration system 18 . Alternatively, the apparatus 10 may include a second processing line 28 on which a second fluff cellulosic web 32 is fed from a second roll of material 30 is unwound and fed to a second fiberization system 34 at a defined web speed, so that a continuous mass flow of a second fiberized material is produced. This can likewise be supplied to the production machine 20, in which case the web speed can also be regulated 38 in the second processing line 28, as described above, by means of a second sensor device 36.

The device 10 according to the prior art requires the use of fluff cellulose material webs 14, 32 in the form of material rolls 12, 30 that can be unwound in a defined manner, since this is the only way to ensure that a continuous mass flow of fluff cellulose material is fed to the production machine 20.

In contrast to this, a device according to the invention is designed and set up so that a starting material can be used in any container form. 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 represented by solid lines, optional components by dashed lines.

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 first be explained on the basis of the basic device components and method steps.

According to FIG. 2, a cellulose material in the form of a cellulose bale 45 is provided as the starting material, the cellulose bale 45 being formed by cellulose mats (not shown) stacked on top of one another. Basically a starting material 42 can be used in the form of any container. First, the starting material 42, for example the entire pulp bale 45 or part thereof, is fed to a comminuting line 46 of the device 40, which includes a comminuting 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 crushed dry without adding water.

The comminution device 48 can comprise a single-shaft or multi-shaft comminutor, for example. It can be equipped with a sieve, which defines a maximum piece size of the comminuted material discharged from the comminution device 48 and thus makes it at least partially homogenized and meterable. The comminuted material can be discharged from the comminuting device 48, for example, by means of a conveyor belt, a screw conveyor, or a suction box. The discharge is preferably carried out with a suction box or a screw conveyor with supported suction. The suction prevents dust from accumulating in the area of the comminution device 48 . In addition, a rapid discharge of the shredded material supported by suction has a positive effect on the shredding quality.

The device 40 includes a material buffer 50, for example a bunker, which is intended to receive the shredded material. In order to feed the comminuted material to the material buffer 50, it can be fed from the outlet of the comminution device 48 into an air duct and transported in the direction of the material buffer 50 by means of an air flow. The air flow can be generated by a transport fan with an open impeller, which is arranged after the comminution device in the material flow of the comminuted material. Alternatively or additionally, a more energy-efficient transport fan with a closed impeller can be provided. This can in particular be located downstream of the material buffer 50, where the comminuted material has already been separated from the air flow and stacked in the material buffer 50 or temporarily stored in another form. A cyclone separator and/or a sieve separator provided specifically for this purpose can be provided for separating the comminuted material from the air flow and/or for intermediate storage of the comminuted material in the material buffer 50 .

The material buffer 50 can be dimensioned in such a way that it can accommodate a larger quantity of comminuted material than can be fed to the comminuting device 48 at once. The material buffer 50 thus enables batch operation in the comminution line 46, i.e. a number of containers of the starting material 42, for example several cellulose bales 45, can be comminuted by means of the comminution device 48 to form comminuted material, which is then fed to the material buffer 50 and, if necessary is cached in this. In this respect, a first method section 52 from the comminution of the starting material 42 to the intermediate storage of the comminuted material in the material buffer 50 can be carried out independently of subsequent production steps. This is indicated in FIG. 2 by a dot-dash line, above which the first method section 52 (batch operation) is shown.

A second method section 53 (continuous or quasi-continuous operation) begins with the removal of the comminuted material from the material buffer 50 (FIG. 2, below the chain-dotted line). For this purpose, the material buffer 50 has a controllable dosing device 54, by means of which the comminuted material can be removed from the material buffer 50 in a dosed manner. The dosing device 54 feeds the comminuted material to a processing line 56 . The controllable dosing device 54 can be designed as a speed-controlled screw conveyor, which accomplishes discharge and dosing of the stacked in the material buffer 50 shredded material and the Processing line 56 supplies a controlled mass flow of shredded material.

The processing line 56 includes a defibration system 58, by means of which the comminuted material is defibered into a defibrated material. The resulting shredded material is then fed to a manufacturing machine 60 of apparatus 40 where an airlaid product or nonwoven 16 is manufactured from it. The fiberization system 58 can be fed with a conveyor belt, a screw conveyor, or with the help of an air stream. According to an advantageous embodiment, the comminuted material is fed directly into a channel assigned to the processing line 56 by the controllable dosing device 54 and fed to the defibrating system 58 by means of an air flow generated by a transport fan. With this type of loading, the material buffer 50 and the fiberization system 58 can be positioned spatially independently of one another and flexibly connected by means of the channel of the processing line 56 . In addition, a change made by the metering device 54 in the metering of the comminuted material fed to the processing line 56 takes effect with a very short time delay in the fiberization system 58 and thus ultimately also in the production machine 60 due to the high transport speed of the air flow, so that a particularly direct control of the production process is possible is, which ultimately has a positive effect on the quality of the airlaid product or nonwoven fabric 16 produced.

The defibration system 58 is configured to defibrate the comminuted material in a substantially dry state without the addition of water. The defibration system 58 may include at least a first hammermill that defibrates the comminuted material. In order to achieve improved defibration quality, the defibration system 58 can additionally have a second hammer mill downstream of the first hammer mill. the the first hammer mill may be provided with a screen to prevent whole, unfragmented pieces of crushed material from exiting the first hammer mill and entering the second hammer mill. The second hammer mill can have narrower and more closely fitting hammers than the first hammer mill and can remove any knots that may be present from the material shredded by the first hammer mill, which ultimately has a positive effect on the quality of the airlaid product or nonwoven fabric 16 produced.

The dry defibrated cellulose material is then fed to the manufacturing machine 60, for example via a channel system connected to the defibration system 58 by means of an air flow generated by a transport fan. The manufacturing machine 60 may be a conventional continuous manufacturing machine 60 such that a continuous mass flow of shredded material must be fed to it in order to obtain a uniform airlaid product or web 16 . In order to achieve this, it is provided that the dosing device 54 is controlled in such a way that the production machine 60 is supplied with a continuous mass flow of shredded material. For this purpose, the device 40 has a control unit 62 which is set up and designed to control the controllable dosing device 54 in a corresponding manner.

According to FIG. 2, the dosing device 54 is controlled on the basis of a characteristic parameter of the mass flow of fiberized material between the fiberization system 58 and the production machine 60. To determine the mass flow of fiberized material, a sensor device 64 is located directly behind the fiberization system 58, for example in the channel 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 by means of other suitable sensors. The actually detected mass flow serves as Control variable for the controllable dosing device 54. If it deviates from a target mass flow, the dosing device 54 is controlled or readjusted (regulation 55) in order to achieve this target mass flow.

Alternatively, the dosing device 54 can be controlled on the basis of a characteristic parameter of the airlaid product or nonwoven 16 produced, for example on the basis of an actual basis weight of the airlaid product or nonwoven 16 detected by means of suitable sensors. If the basis weight actually detected deviates from a target -Area weight decreases, the dosing device is controlled or readjusted accordingly in order to feed the processing line with an adjusted amount of shredded material and thus to achieve the target area weight. In principle, the dosing device 54 can be controlled in such a way that the processing line 56 is supplied with a continuous and in particular constant, i.e. temporally unchanged, mass flow of comminuted material.

In FIG. 2 , further components of the device 40 that can be optionally provided are shown with dashed lines. The comminution line 46 can include a cleaning device 66 which is connected downstream of the comminution device 48 and is arranged, for example, in a channel system for transporting the comminuted material. The cleaning device 66 can comprise a magnetic separator which frees the comminuted material from metallic foreign substances. The cleaning device 66 can be followed by a sorting device 68 which, for example, comprises a cyclone separator which ejects heavy parts before the comminuted, cleaned and sorted material is fed to the material buffer 50 .

In a comparable manner, alternatively or additionally, a cleaning device 70 and/or a sorting device 72 can be arranged in the processing line 56 behind the fiberization system 58 in order to to clean shredded material from foreign and disruptive substances and to sort it, for example with regard to its piece size. A magnetic separator, a cyclone separator and/or a sieve separator can be used for this purpose.

In addition, the device 40 in front of the production machine 60 can have a feed 74 for further materials that have already been completely processed. Furthermore, the device 40 can have a second processing line 56.2, which can be fed with shredded material by means of a controllable second dosing device 54.2 of the material buffer 50. Each processing line 56, 56.2 is therefore 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 each processing line 56, 56.2 can be supplied with a separately definable quantity of comminuted material from the material buffer 50.

Analogously to the processing line 56, the second processing line 56.2 includes a second defibration system 58.2 for defibrating comminuted material. In addition, 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 fiberizing system 58.2 or also behind the second cleaning device 70.2 or the second sorting device 72.2, which detects the mass flow of fiberized material. If the actually recorded mass flow deviates from a target mass flow defined for the second processing line 56.2, then on this basis the second Second dosing device 54.2 assigned to processing line 56.2 is readjusted or controlled (control 55.2) in order to achieve the target mass flow.

When producing a multi-layer airlaid product or non-woven fabric 16, each of the processing lines 56, 56.2 can be provided for the starting material

42 to fray for a product layer and to feed the manufacturing machine 60 .

Each processing line 56, 56.2 can by means of their assigned

Dosing device 54, 54.2 are charged for this purpose with the appropriate amount of crushed starting material.

Various materials can be used to produce an airlaid product or nonwoven fabric 16, in particular, in addition to the starting material 42, a second starting material 43 and a third material 44 can be used. For example, the starting material 42 can be long-fiber pulp, the second starting material

43 short-fiber pulp, each in bale form, and as the third starting material 44 an already shredded scrap material can be used (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.

Since long-fiber and short-fiber pulp bales behave similarly during comminution, they can be comminuted with the same comminution device 48 in the comminution line 46 and optionally be 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 crushing, cleaning and sorting of the starting materials 42, 43 takes place separately, ie for example one after the other, so that the resulting crushed material comprises only one type of material. To each of the different comminuted materials in the material buffer 50, 76 assigned to it, a channel system of the comminution line 46 can be switched over in such a way that comminuted material from long-fiber pulp 42 is fed to the bunker 50 and comminuted material from short-fiber pulp 43 is fed to the bunker 76. The scrap material 44 that has already been shredded is fed to the third material bunker 78 . For stacking the respective material 42, 43, 44, each material buffer 50, 76, 78 preferably has a cyclone separator and/or a sieve separator.

The second and third material buffers 76, 78 can each have two dosing devices 80, 80.2 and 82, 82.2, which are each assigned to one of the processing lines 56, 56.2 and can be controlled independently of one another. A defined material composition of comminuted material with freely selectable proportions of long-fiber pulp 42, short-fiber pulp 43 and scrap material 44 can thus be fed to each of the two processing lines 56, 56.2 independently of one another via the control unit 62. All of the comminuted materials fed to a respective processing line 56, 56.2 are defibrated together in the defibrating system 58, 58.2 arranged in the corresponding processing line 56, 56.2, and are mixed in the process. Thus, a multi-layer, according to FIG. 2 two-layer, airlaid product or nonwoven product 16 can be produced with different material compositions of the individual product layers.

As already described above for the dosing devices 54, 54.2 of the material buffer 50, the mass flow in the respective processing line 56, 56.2 can be detected by means of the sensor devices 64, 64.2 of the two processing lines 56, 56.2. On the basis of the data recorded by the sensor device 64, the dosing devices 54, 80, 82 assigned to the processing line 56 are readjusted or controlled (regulation 55, 81, 83). On the basis of the data recorded by the second sensor device 64.2, the data of the second Dosing devices 54.2, 80.2, 82.2 assigned to processing line 56.2 are readjusted or controlled (regulation 55.2, 81.2, 83.2).

3 shows a further device 40 for producing a three-layer airlaid product or non-woven fabric 16 from three different starting materials 42, 43, 44, which are fed to the device 40 in the form of bales. As described in connection with FIG. 2, it can be long-fiber pulp 42, short-fiber pulp 43 and waste material 44, for example. In order to comminute the starting materials 42, 43, 44, the device 40 has a first comminution 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 of which has a comminution device 48.1, 48.2, a cleaning device 66.1, 66.2 and a sorting device 68.1, 68.2. A separate crushing device 48.2 and a separate magnetic separator and cyclone separator for cleaning and sorting are advantageously used for the scrap material 44, since this allows adaptation to the requirements of the scrap material 44 in terms of shape, material properties and production volume. Thus, the long-fiber and short-fiber pulp materials 42, 43 can be shredded independently of the scrap material 44, the shredding quality can be improved for all starting materials 42, 43, 44, and due to the typically lower amount of scrap material used, smaller machines can be used in the second shredding line 46.2 and thus energy can be saved.

Each of the three comminuted starting materials 42, 43, 44 is fed to a separate material buffer 50, 76, 78. In order to produce the three product layers, which in particular each have 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 Metering 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 defibration system 58.1, 58.2, 58.3 for each processing line 56.1, 56.2, 56.3, the comminuted material supplied to each processing line is defibrated and homogeneously mixed, and then fed to a production machine 60 for producing a three-layer airlaid product or nonwoven fabric 16.

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 described above in connection with FIG.

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 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 to be activated, if necessary, in such a way that the target mass flow is achieved and a correspondingly continuous, in particular temporally constant, mass flow is supplied to the production machine 60.

It is clear from the above statements that the concept according to the invention can be easily adapted to the respective profile of requirements. The three processing lines 56.1, 56.2, 56.3 and thus the three layers of the airlaid product or non-woven fabric 16 can be composed of the three materials 42, 43, 44, respectively, independently. Reference character list

10 Prior art device

11 processing line

12 roll of material

14 fluff pulp web

16 airlaid product or non-woven fabric

18 defibration system

20 crafting machine

22 sensor setup

24 Control of the web speed of the first processing line

26 Supply of finished materials

28 second processing line

30 second roll of material

32 second fluff pulp web

34 second defibration system

36 second sensor device

38 Control of the web speed of the second processing line

40 Device for producing an airlaid product or a non-woven fabric

42 starting material

43 second starting material

44 third starting material

45 pulp bales

46 shredding line

46.1 first crushing line

46.2 second crushing line

48 crushing device

48.1 first crushing device

48.2 second crushing device

50 material buffers

52 first part of the procedure

53 second part of the procedure

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 defibration system

58.1 first defibration system

58.2 second defibration system 58.3 third defibration system 60 manufacturing machine

62 control unit

64 sensor setup

64.1 first sensor device

64.2 second sensor device

64.3 third sensor device

66 cleaning device for shredded material

66.1 Cleaning device for crushed material of the first crushing line

66.2 Cleaning device for crushed material of the second crushing line

68 sorting device for shredded material

68.1 Sorting device for crushed material of the first crushing line

68.2 Sorting device for crushed material of the second crushing line

70 shredded material cleaning device

70.2 second cleaning device for shredded material

72 shredded material sorting device

72.2 second sorting device for shredded material

74 Supply of further materials

76 second material buffer

78 third material buffer

80 controllable metering device of the second material buffer

80.1 first controllable dosing device of the second material buffer

80.2 second controllable dosing device of the second material buffer

80.3 third controllable dosing device of the second material buffer

81 Control of the dosing device of the second material buffer

81.2 Control of the second dosing device of the second material buffer

82 controllable dosing device of the third material buffer

82.1 first controllable dosing device of the third material buffer

82.2 second controllable dosing device of the third material buffer

82.3 third controllable dosing device of the third material buffer

83 Control of the dosing device of the third material buffer

83.2 Control of the second dosing device of the third material buffer

Claims

Expectations

1. A method for producing an airlaid product or a nonwoven fabric (16) from a starting material (42), in particular from a cellulose material in the form of a bundle, such as a cellulose bale (45), in which the starting material (42) is processed in at least one shredding line (46, 46.1, 46.2) is comminuted into a comminuted material by means of at least one comminuting device (48, 48.1, 48.2), the comminuted material is fed to at least one material buffer (50, 76, 78), the comminuted material is fed by means of at least one dosing device (54 , 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) taken from the at least one material buffer (50, 76, 78) and at least one processing line (56, 56.1, 56.2, 56.3) is fed with at least one defibration system (58, 58.1, 58.2, 58.3), in which the comminuted material is defibered into a defibrated material, the defibrated material of a manufacturing machine (60) is fed and processed into an airlaid product or a nonwoven (16), the at least one dosing device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) being controlled in this way that the production machine (60) is supplied with a continuous mass flow of shredded material.

2. The method according to at least 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 dosing device is controlled on the basis of a characteristic parameter of the mass flow of shredded material detected by means of a sensor system (64, 64.1, 64.2, 64.3).

4. The method according to at least one of the preceding claims, wherein the dosing device is controlled on the basis of a sensor-detected characteristic parameter of the airlaid product or nonwoven fabric (16) produced, in particular wherein the parameter is a basis weight.

5. The method according to at least one of the preceding claims, wherein the dosing device is controlled in such a way that a continuous mass flow of comminuted material is fed to a processing line (56, 56.1, 56.2, 56.3) assigned to the dosing device.

6. The method according to at least one of the preceding claims, wherein, in particular for the production of a multi-layer product comprising at least two layers of an airlaid product or non-woven fabric (16), the comminuted material is metered by means of at least two metering devices from a material buffer (50 , 76, 78) and fed to at least two processing lines (56, 56.1, 56.2, 56.3), each with a defibration system (58, 58.1, 58.2, 58.3), in which the comminuted material is defibered into the fibrillated material, each the at least two dosing devices are assigned to one of the at least two processing lines (56, 56.1, 56.2, 56.3), and wherein the shredded material of the at least two processing lines (56, 56.1, 56.2, 56.3) is fed to the same manufacturing machine (60) and is fed therein is processed into an, in particular multi-layer, airlaid product or non-woven fabric (16).

7. The method according to at least one of the preceding claims, wherein - if present - at least two metering devices of a material buffer (50, 76, 78) are controlled independently of one another.

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

9. The method according to at least claim 8, wherein the at least two different starting materials (42, 43, 44) are comminuted by means of the same comminuting line (46) or comminuting device (48), in particular separately, into at least two different comminuted materials.

10. The method according to at least claim 8, wherein the at least two different starting materials (42, 43, 44) are crushed into at least two different crushed materials by means of at least two crushing lines (46.1, 46.2) or crushing devices (48.1, 48.2).

11. The method according to at least claim 9 or 10, wherein each of the at least two different comminuted materials is supplied to a separate material buffer (50, 76, 78). 12. The method according to at least one of the preceding claims, wherein each processing line (56, 56.1, 56.2, 56.3) is supplied with a defined material composition of at least two different comminuted materials from at least two material buffers (50, 76, 78) by means of dosing devices assigned to them can.

13. The method according to at least one of the preceding claims, wherein the at least one starting material (42, 43, 44) is comminuted at least essentially dry, in particular without the addition of water or solvent, by means of the at least one comminution device (48, 48.1, 48.2) and /or is shredded.

14. The method according to at least one of the preceding claims, wherein the at least one comminuted material is sorted with regard to a characteristic parameter, in particular by means of a sieve and/or a cyclone separator (68, 68.1, 68.2), and/or wherein the at least one shredded material Material is sorted with regard to a characteristic parameter, in particular by means of a sieve and/or a cyclone separator (72, 72.2).

15. The method according to at least one of the preceding claims, wherein the at least one comminuted material is cleaned, in particular by means of a cyclone separator and/or a magnetic separator (66,

66.1. 66.2), and/or wherein the at least one shredded material is cleaned, in particular by means of a cyclone separator and/or a magnetic separator (70,

70.2). 16. Device (40) for producing an airlaid product or a

Nonwoven fabric (16) made from at least one starting material (42, 43, 44), in particular from a cellulose material in the form of a bundle, such as a cellulose bale (45), comprising at least one comminution line (46, 46.1, 46.2) with at least one comminution device (48 , 48.1, 48.2) for crushing the at least one starting material (42, 43, 44) into at least one crushed material, at least one material buffer (50, 76, 78) for receiving a crushed material assigned to the material buffer (50, 76, 78). , wherein the at least one material buffer (50, 76, 78) 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 the metered removal of the respectively assigned comminuted material material from the at least one material buffer (50, 76, 78) and for feeding the at least one comminuted material to at least one processing line (56, 56.1, 56.2, 56.3), the z uat least one processing line (56, 56.1, 56.2, 56.3) comprises at least one defibration system (58, 58.1, 58.2, 58.3), which is designed to defiber the at least one comminuted material into at least one fibrillated material, and a production machine (60) for producing an airlaid product or a non-woven fabric (16) from the at least one shredded material, a control unit (62) being provided which is set up and configured to have at least one dosing device (54, 54.1, 54.2, 54.3, 80, 80.1, 80.2, 80.3, 82, 82.1, 82.2, 82.3) in such a way that the manufacturing machine (60) is supplied with a continuous mass flow of fiberized material, 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.