Method and machine for producing an air-laid fiber web

Abstract

The invention relates to a method for producing an air-laid fibrous web from a fibrous material (200), in which the fibrous material (200) is processed into a fiberized fibrous material (208) using a low-water process, and the fibrous web is formed from the fiberized fibrous material in an air-laying process using at least one forming device. During the processing, the fibrous material is processed stepwise into fiberized fibrous material (208) at least in a comminution device (221) and then in at least one fiberizing device (222, 223) and transported further in a fiber / air stream.The invention is characterized in that an air supply device (91) is provided between a last fiber / air stream in the transport direction of the fiber / air stream, the at least one fiberizing device (223) and the forming device, by means of which additional air is supplied to the last fiber / air stream exiting the last fiberizing device (223) before it enters the forming device.

Description

The invention relates to a method for producing an air laid fibrous web, in particular a dry formed paper, board or tissue web or a nonwoven web of a fiber material, in particular a bale- or plate-shaped fiber material, in which the fiber material is formed from a non-woven web.in a treatment process to form a defibrated fibre material, the material is treated with low water content, preferably without water;forming a planar fiber laid scrim from the defibrated fiber material in a forming device by means of an air flow in a dry forming process;in a consolidation process, the planar fibrous web is consolidated to the fibrous web by applying pressure and / or temperature; wherein, in the processing process a), the fiber material is comminuted in at least one comminution device to give individualized, chip-shaped fiber material and b) thereafter, in at least one first comminution device and one second comminution device, the individualized, chip-shaped fiber material is processed further in stages to give defibrated fiber material and the fiber material is transported as a fiber / air stream via the processing process and up to the dry forming process.The invention also relates to a machine for producing an air-laid fibrous web, in particular a dry-formed paper, board or tissue web or a nonwoven web, from a, in particular bale- or plate-shaped, fibrous material, in particular for carrying out the method according to claim 1, comprising:a low-water fiber material treatment plant; anda fiber web manufacturing plant; wherein the low water fiber material treatment plant further comprises:at least one comminution device; andat least one defibrating device; anda fiber / air flow transport system connectable to the fiber web manufacturing plant; wherein the fibrous web manufacturing plant further comprises:at least one forming device; andat least one solidification device; anda reeling device.Many fibrous webs and in particular paper, board or tissue webs have been produced in the past and are still produced on an industrial scale almost exclusively by wet processes. For this purpose, if waste paper is not used, bale market pulp is usually dissolved in a vat in large amounts of water, so that a fiber suspension is obtained which consists to the extent of about 99% by weight of water and only to the extent of about 1% by weight of fibers. The fiber suspension is then applied to a forming wire via a headbox for sheet formation. The fibrous web is then dewatered or dried by pressure and heat until it can be wound up at the end or processed in another way. The wet process has the advantage that hydrogen bonds form between the individual fibers during dewatering or drying, which hydrogen bonds impart the necessary strength to the fibrous web. However, a disadvantage of this process is that large amounts of energy are required for drying the fibrous web. Especially against the background of current climate conversion, therefore, alternatives to this classic wet method are being intensively sought.As an alternative to the wet process, the dry air laying process or dry laying process is already known, among others, in which fibers are laid down in the largely dry state to form a fibrous web. In order to impart the necessary strength to the fibrous web, only relatively small amounts of water (for forming hydrogen bonds) and / or other binders are added to the latter. This results in significantly less energy having to be applied for the drying. One challenge with this method is to achieve a good or uniform fiber distribution (also called formation). Unlike in the suspension, the dry fibers tend to form flakes in an undesirable manner. A good separation of the fibers is therefore very important. For this reason, the dry air laying method is generally based on what is known as fluff pulp. This is fresh-fiber pulp which has been pretreated in such a way that the individual fibers already have fewer and / or weaker bonds to one another. This makes the fluff pulp bulkier, absorbent and more suitable for the dry airlaying process. However, fluff pulp, which is typically produced as roll stock, is much more expensive than ordinary bale market pulp, as typically used in the paper industry. Therefore, the dry air-laying process is nowadays also used primarily only for the production of sanity products, such as diapers, and not for the production of paper, cardboard or tissue webs, at least not on an industrial scale. For such an industrial scale, the use of fluff pulp would be uneconomical despite the currently high energy costs.It would therefore be advantageous if a possibility were to be able to produce a fibrous web, in particular a paper, board or tissue webs or nonwoven web, on an industrial scale, with sufficiently good formation in the dry air laying process or dry forming process from the relatively inexpensive conventional bale market pulp.The production of a fibrous web from bale pulp by the dry air laying method is disclosed in the publication WO 2023 / 280 812 A1. A method and an apparatus for producing an air-laid ("air-laid") product or a nonwoven from a starting material, in particular from a cellulose material in the form of a bundle, such as a cellulose bale, with a higher economic efficiency and more flexible applicability, is disclosed. For the fibrous web production plant, the fibrous material processing plant with metering devices is intended to provide a continuous mass flow of defibrated fibrous material. The publication discloses various solutions and arrangements with material buffers and a plurality of comminution and fiberizing systems in order to supply a constant mass flow to the fiberizing systems and to the downstream fibrous web production plant.Furthermore, for example, the publications DE 10 2023 129 657 A1, DE 10 2023 129 655 A1, U.S. Pat. No. 2020 / 0 149 219 A1, EP 3 266 918 B1, EP 4 339 344 A1, EP 3 450 125 A1 and DE 10 2022 127 320 A1 disclose methods and machines for producing an air-laid fibrous web.However, tests with these configurations have shown that the result, in particular the formation of the airlaid fibrous web, is still unsatisfactory with this method as well.This is especially evident when the production speeds are increased to an industrial, economical scale. The air laid fibrous web still has unsatisfactory qualities, such as, for example, with regard to the formation, the feel (haptics) and the appearance (appearance). The surface weight profiling in machine (MD) and transverse (CD) directions also has too great a range of variation.By "dry-formed" it is equivalently possible to mean the terms "dry-formed", "air-formed", "dry-laid" or "dry-formed".The object of the invention is to specify a method and an apparatus for the low-water or dry production of a high-quality air laid fibrous web for a constant, high, industrial production speed with a low use of water and at the same time high quality properties of the fibrous web. In particular, the formation of the air laid fibrous web in the dry forming process is to be improved.In particular, the low-water, preferably water-free, treatment process to give a defibrated fiber material is to be improved, so that substantially defibrated fiber material consisting of individual fibers and no or a very small proportion of fiber bundles with nodes is produced.The fibrous web should have high mechanical strengths, preferably tear strengths or tensile strengths in the dry as well as wet state, and quality factors such as a good and uniform formation, a constant surface weight profile in the machine MD and transverse direction CD, and quality parameters with regard to the appearance and the haptics.Furthermore, for example, in the case of a preferably produced tissue web having low and high pressure zones, the feel, the appearance and the absorption rates are also very decisive; this is shown, for example, in the case of produced wipes for domestic use, where the customer is expecting a high absorbency, a good appearance and feel.The method for producing a fibrous web further comprises at least one air supply device being provided between a last of the at least one defibering device in the transport direction of the fiber / air stream and the forming device, by means of which air additional air is supplied to the last fiber / air stream exiting the last defibering device before it enters the forming device.According to the invention, a method for producing a fibrous web is proposed, which is distinguished by the characterizing part of claim 1.The inventors have recognized that an improvement in the formation of the airlaid fibrous web can be achieved by supplying additional air after the last defibering device and before the dry forming process. This is due to decoupling the fiberization of the fiber material and the dry forming process. In this case, it has proven to be particularly advantageous since decoupling can be achieved in a continuous process without an interruption, for example by an intermediate storage facility. Furthermore, this means that the at least one last fiberizing device, which is arranged upstream of the forming device, can operate at an optimum operating point before the addition of additional air, so that substantially individual fibers and / or substantially knot-free fiber bundles are produced. Furthermore, the desired fiber parameters, such as fiber lengths and fiber surfaces, can also be exactly adjusted and controlled.By supplying the additional air after the last fiberizing device and before the forming device, the exact volume flow for the forming device can likewise be adjusted and controlled, so that these operate at an optimum operating point and can form a fiber laid scrim from the fiberized fiber material, which laid scrim conforms to the requirements.For production on an industrial scale, a high, continuous production speed or fibrous web speed of greater than or equal to 300 m / min, in particular greater than or equal to 400 m / min, preferably greater than or equal to 500 m / min, particularly preferably greater than 600 m / min or greater than 800 m / min, and a width of the continuously produced fibrous web of greater than or equal to 0.5 m, preferably greater than or equal to 1 m, in particular greater than or equal to 2.7 m and less than or equal to 7.2 m, to less than or equal to 10 m, are sought. The proposed method is particularly suitable for producing such fibrous webs.An air laid fibrous web can be, for example, a dry formed paper, board or tissue web or a nonwoven web, usually in the area weight range from 5 g / m 2 to 600 g / m 2. In an alternative embodiment of the process, the fibrous web produced is a dry formed tissue web having low and high pressure zones. Particularly preferably, a dry-formed tissue web is a dry-formed tissue web having a basis weight of 5 g / m 2 to 75 g / m 2, in particular of 15 g / m 2 to 60 g / m 2, preferably of 25 g / m 2 to 45 g / m 2, particularly preferably of 28 g / m 2 to 42 g / m 2. The proposed method is particularly suitable for producing such fibrous webs.The dry-formed tissue web can be configured here as a single layer, in particular two-, three-, four- or multilayer. For example, in a possible embodiment with a plurality of dry forming apparatuses, it is easily conceivable to introduce different fiber materials per dry forming apparatus. This can lead, for example, in three dry forming apparatuses to a three-ply fibrous web having an upper, middle and lower ply. In principle, when using the same fiber material, a single-ply fibrous web is used in an embodiment with a plurality of dry forming apparatuses, even if this web is formed by, for example, three dry forming apparatuses.To distinguish between the fibrous webs produced, for example a tissue, paper or board web or a nonwoven web (in English "nonwoven"), the following distinction is made, which is based on the fiber length, density and type of fiber bonding.A tissue, paper or board web is understood to mean a fibrous web having predominantly average fiber lengths, preferably shorter fiber lengths compared to a nonwoven web, of less than or equal to 5 mm, in particular less than or equal to 4 mm, preferably less than or equal to 3 mm, a predominant bond by hydrogen bonds (OH bonds) and a bulk density of greater than or equal to 0.4 g / cm 3.The fibers used in a tissue, paper or board web are additionally distinguished in that they have a slenderness ratio of fiber length to fiber diameter of less than or equal to 200, in particular less than or equal to 150, preferably less than or equal to 100. The proposed method is particularly suitable for producing such fibrous webs.A nonwoven web, which likewise consists mainly of fibers, is understood as a substantial delimitation from a tissue, paper or board web to mean that the nonwoven web has a fiber content of between 30% and 50% of very long fibers having an average fiber length of more than 5 mm or even continuous fibers which determine the nonwoven character. In the case of a nonwoven web, the aspect ratio of fiber length to fiber diameter of the fibers of greater than or equal to 300 is also sought.The remaining fibre portion of a nonwoven web can be composed otherwise and the bulk density should be below 0.40 g / cm 3 in order to add to the nonwoven webs.A further distinguishing feature in the case of a nonwoven web to form a tissue, paper or cardboard web lies in the manner of fiber bonding of the fibers to one another, wherein in the nonwoven web the fibers are achieved by a form fit (by entanglement, for example "spun-lacing" or "hydro-deangling") and / or by cohesion and / or by adhesion. However, nonwoven webs produced by the wet nonwoven fabric process, which is similar to the process of papermaking, often also occur, once as a nonwoven web, otherwise referred to as a long-fiber special paper web.A structured and / or consolidated fibrous web, preferably a tissue web having low- and high-pressure zones, is understood to mean that the fibrous web retains a constant basis weight distribution in the machine direction MD and the transverse direction CD after the structuring. This is different in comparison with an embossing or structuring method which is known in tissue web production under the English term "embossing", since here the fibers are "bent into" the desired structure and the previously formed fiber laid scrim with existing fiber bonds partially dissolves with respect to one another, since the fibers pull apart in the fiber laid scrim and thus obtain different basis weights by means of this measure. In the present structuring and / or consolidation and / or heating, the laid fiber web is consolidated free from fiber elongations relative to one another.A fibrous web having low and high pressure zones, preferably a tissue web having low and high pressure zones, is further characterized in that the fibrous web is consolidated, compressed or pressed over the entire surface or over the surface, that is to say the low and high pressure zones are consolidated in a different ratio to one another.According to the invention, the method is characterized in that the additionally supplied air is increased by a factor greater than or equal to 2, preferably 2.25, particularly preferably 2.50, to the last fiber / air stream exiting with a first volume flow before it enters the forming apparatus to form a last fiber / air stream with a second volume flow.Advantageously, the second volume flow upstream of the forming device is increased to such an extent that at least one bisection of the concentration occurs in the last fiberizing device.In an alternative embodiment, the method is characterized in that a volume flow of the fiber / air flow through the last of the at least one defibrating device, preferably and a first defibrating device, is kept constant or increased.It is advantageous if the volume flow through the defibrating device is kept constant; preferably, the volume flow in the defibrating device is increased. Losses occurring in the fiberizing device can thus be compensated for and the formation of individual fibers and / or fiber bundles with a lower proportion of nodes can also be achieved.In an alternative embodiment, the method is characterized in that a volume flow of the additionally supplied air is set in such a way that a negative pressure in and / or directly after the at least one last fiberizing device, preferably and / or a first fiberizing device, of more than 4 kPa, in particular more than 5 kPa, preferably more than 7 kPa, is set.Advantageously, the last fiberizing device can be operated at an optimized operating point with respect to the reduced pressure in the last fiberizing device by the volume flow of the supplied air or the second volume flow of the last fiber / air mixture to be set, which can lead to a better discharge of the fiberized fiber material from the fiberizing device and also assists the formation of individual fibers and / or fiber bundles with a lower proportion of nodes.A negative pressure can assist in discharging fiber material from the fiberizing device and, for example, reduce the residence time of the fiber material in the fiberizing device.In an alternative embodiment, the method is characterized in that a second air supply device is provided directly upstream of a dry forming device, which is arranged downstream of the at least one air supply device, by means of which a second air is supplied to the last fiber / air stream increased to a second volume flow, in particular by an exhaust air stream from the dry forming process, preferably by at least one fiber / exhaust air stream from a suction box and / or an edge suction device and / or a transfer tail cutting device, which increases the second volume flow of the last fiber / air stream to a third volume flow of the last fiber / air stream, which is increased by a factor greater than or equal to 1.3, in particular greater than or equal to 1.5, preferably less than or equal to 2.Advantageously, the further air supply can be carried out stepwise, which makes it possible to carry out a reduction of the required air supply devices, such as air pumps, air fans, etc., and also of the fiber / air flow transport system, smaller and more efficiently in the case of longer transport paths. An efficient return of the waste from the machine can also advantageously be arranged just before the dry forming device; this is advantageous on the one hand for an efficient use of the fiber material and also the short return transport systems.For a particularly efficient return, the third volume flow should be increased only slightly.In an alternative embodiment, the method is characterized in that a third air supply device is provided, which is arranged downstream of the at least one air supply device and / or a second air supply device, by means of which the last fiber / air stream entering the forming device with a second or third volume flow is increased to a fourth volume flow by a factor greater than or equal to 3, in particular greater than or equal to 3.5, particularly preferably greater than or equal to 4.0, preferably less than or equal to 5. A fourth air supply device within the dry forming device is particularly advantageous, which immediately before the formation of the flat fiber web dilutes the fiber / air stream to such an extent, or reduces the fiber concentration in the fiber / air stream to such an extent, or increases the third volume stream to such an extent that at least one third of the concentration of the fibers is established.The high amounts of air lead to a final dissolution of the few fiber bundles with a low proportion of nodes and allow an optimum formation of the individual fibers and / or the fiber bundles substantially free of nodes of the laid fiber fabric on the forming belt.In an alternative embodiment, the method is characterized in that a first fiberizing device is provided, which is arranged upstream of the last fiberizing devices in the transport direction of the fiber / air stream. For improved defibering of the fiber material, a stepwise defibering with at least a first and a last defibering device is advantageous. The first defibrating device can relieve the last defibrating device and assist in improving the formation of single fibers and / or fiber bundles with a lower proportion of nodes.In an alternative embodiment, the method is characterized in that a fourth air supply device is provided, which is arranged downstream of the first fiberizing device, by means of which additional air is supplied to a second fiber / air stream exiting from the first fiberizing devices.It has proven to be advantageous if additional air is supplied during a stepwise fiberizing even after the first fiberizing, this improves the discharge of fiberized fiber material from the first fiberizing device and enables improved transport up to the second or last fiberizing device.In an alternative embodiment, the method is characterized in that at least one fifth air feed is provided, which is arranged upstream of the last defibrating device and / or the first defibrating device, by means of which additional air is fed to a third fiber / air stream entering the last defibrating device before the entry and / or additional air is fed to a first fiber / air stream entering the first defibrating device before the entry, in particular of single-out, chip-shaped fiber material.Advantageously, the defibering process in the defibering device can be regulated and controlled even more efficiently by a fourth air supply arranged upstream.A further supply of additional air before and after, instead of only after, the defibrating devices makes it possible to have the defibrating in the respective defibrating devices set and controlled even more precisely. In particular, the pressure differences from before to after the fiberizing device can be adjusted exactly, which has an advantageous effect on the fiberizing.In an alternative embodiment, the method is characterized in that a mass flow of the fiber material in the fiber / air flow is kept substantially constant before and after the at least one last fiberizing device, preferably up to the forming device.In an alternative embodiment, the method is characterized in that the chip-shaped fiber material is guided from the at least one comminution device in a first fiber / air stream to the first fiberizing device and in that a first fiberized fiber material is guided from the first fiberizing device in a second fiber / air stream to the last fiberizing device and in that a last fiberized fiber material is supplied to the forming device in a last fiber / air stream and in that the first, second and last fiber / air stream are each acted upon with additional air, such that the proportion of individual fibers and / or fiber bundles in the last fiber / air stream is smaller than the proportion of individual fibers and / or fiber bundles in the second fiber / air stream and smaller than in the first fiber / air stream.In an alternative embodiment, the method is characterized in that a compressed intermediate web of individual fibers and / or fiber bundles with individualized nodes is formed from the first defibrated material between the first defibrating device and the second defibrating device, and in that the intermediate web is fed to the second defibrating device directly or in a precomminuted form.Advantageously, by forming a compressed, preferably slightly compressed, intermediate web, decoupling of the mass flow from the first to the last defibering device can be achieved. This further means that the comminution devices can be operated at a respective optimum coordinated operating point and a buffering possibility of a few seconds of fiber material storage capacity can be achieved by the intermediate web, such that a constant mass flow control for the dry forming process of less than + / - 4% mass deviation, for example of the final basis weight of the fiber material web, can be achieved at production speeds of more than 300 m / min, in particular more than 400 m / min, preferably more than 500 m / min.The machine for producing an air-laid fibrous web further comprises at least one air supply device being included between the at least one defibering device and the forming device.The machine according to the invention for producing an air laid fibrous web is characterized by the characterizing part of claim 13.In an alternative embodiment, the machine is characterized in that a second air supply device is provided directly upstream of a dry forming device, which is arranged downstream of the at least one air supply device.In an alternative embodiment, the machine is characterized in that a third air supply device is provided, which is arranged downstream of the at least one air supply device and / or the second air supply device.The defibrated fibre material exiting from the last defibrating device is gradually diluted further with air until it is laid as a fibre laid scrim in the dry forming device, in particular on a revolving forming screen. An arrangement of up to three air supply devices makes it possible to provide an optimally matched fiber / air mixture for the individual components. Furthermore, with the required high air quantities for the final formation of the fiber scrim, it makes it possible to reduce the losses in the transport system of the fiber / air stream and not to over-dimension the air supply devices unnecessarily with regard to their design, such as the drive power, for example.The invention expressly also extends to such embodiments which are not given by combinations of features from explicit references back to the claims, whereby the disclosed features of the invention can be combined with one another as desired, insofar as this is technically expedient.Further features and advantages of the invention will become apparent from the following description of a preferred exemplary embodiment with reference to the drawing.The invention is explained below with reference to the following figures. FIG. 1 shows a schematic illustration of a simplified fiber material processing plant 2 for the low-water processing of fiber material 200; FIG. 2 shows a schematic illustration of a fibrous web production plant 3 for producing a dry-formed fibrous web 309.To clarify the individual directions, a superordinate, Cartesian coordinate system is set up in the figures, on which system the individual directions can be clarified. The x direction here illustrates the extension in the longitudinal direction, which is also referred to as the machine direction MD (machine direction). The y direction corresponds to the direction perpendicular to the machine direction and is referred to as cross direction CD (cross direction), while the z direction corresponds to the height direction.Possibly further transport and / or movement directions of further features are marked with separate arrows.FIGS. 1 and 2 show a possible embodiment of a machine 1 or of a production method, in particular on an industrial scale, for producing an, in particular continuously, air-laid fibrous web 309, in particular a dry-formed paper, board or tissue web or a nonwoven web, in particular a tissue web having low-pressure and high-pressure zones, particularly preferably a tissue web having a basis weight of 5 g / m 2 to 75 g / m 2, in schematic illustration.The fibrous web production plant 3 for producing a continuous fibrous web 309 is designed for a high, continuous production speed of greater than or equal to 300 m / min, in particular greater than or equal to 400 m / min, preferably greater than or equal to 500 m / min.The width of the continuously produced fibrous web 309 can be designed to be greater than or equal to 0.5 m to less than or equal to 10 m, in accordance with the operator requirements. For example, in tissue machines it is possible to make them "single width" or "double width" as is customary on the market, which usually corresponds to a width of about 2.7 m to 3.6 m in a "single width" construction.The typically produced basis weights of the continuously produced fibrous web 309 are in this case in the range of greater than or equal to 5 g / m 2 to less than or equal to 400 g / m 2, preferably in the case of a tissue web of greater than or equal to 5 g / m 2 to less than or equal to 75 g / m 2, particularly preferably in the case of a tissue web of 28 g / m 2 to 42 g / m 2.This results in very high mass flows of required fiber material per hour, wherein a fiber material processing plant 2 should be designed in such a way as to provide more than 500 kg / h, in particular more than 1000 kg / h, preferably more than 1500 kg / h of defibrated fiber material 209.These boundary conditions have a direct influence on required quantities, storage volumes, transport capacities and transport paths of the fiber material. It is therefore decisive to consider the fiber material processing plant 2 and the fibrous web production plant 3, which are in direct operative connection with one another, as a common machine 1.FIG. 1 schematically represents a possible embodiment of a low-water treatment or a low-water fiber material treatment plant 2, in which the defibrated fiber material 209, preferably individual fibers and / or fiber bundles, is produced in stages essentially free of nodes, for example from fiber material 200, in particular market pulp and / or fiber-containing recycled material as bale product 200, by at least one comminution device 221 and at least two defibration devices 222, 223 connected in series or one after the other. During fiber material processing and further transport, the fiber material or comminuted or defibrated fiber material always form a fiber / air mixture with varying concentrations of fibers dissolved in air.The fiber material processing plant 2 or the fiber material processing process, in particular at production speeds of more than 300 m / min or at a mass flow of required fiber material of more than 500 kg / h, comprises at least as essential features:• at least one comminution device 221,• at least one, preferably two, defibrating device(s) 222, 223,• at least one fiber / air flow transport system.The fiber material processing plant 2 is suitable for processing a defibrated fiber material from a starting material, in particular fiber material, preferably market pulp and / or recycled fiber material in the form of a bale, low in water, preferably waterless, in particular at production speeds of more than 300 m / min or at a mass flow of required fiber material of more than 500 kg / h. The fiber material processing process in the fiber material processing plant 2 comprises at least as essential processes or method steps:• at least one comminution process,• at least one, preferably two, defibering process(s),• at least one fiber / air flow transport process.If the comminuted or defibrated fibre material is transported through a processing device or from one processing device to a next processing device, a fibre / air stream is referred to. Before and / or after comminution or comminution has taken place, a further air stream or else a further fiber / air stream 91, 92, 93, 94, 95, 96 can be fed to the fiber material or a fiber / air stream, respectively, and the fiber / air stream can be fed via a distribution duct or a plurality of distribution ducts to a fibrous web production plant 3 illustrated in FIG. 2 for producing a dry-formed fibrous web 309. The fiber / air flow has a volumetric and mass flow.A parallel arrangement of a plurality of fiber material processing installations 2 is likewise conceivable, which can feed a single fiber web production installation 3 (FIG. 2 ). This is advantageous if a fiber material processing plant 2 alone cannot produce the required amount of defibrated fiber material and / or different types or types of starting material 200 or fiber material 200 are used.This can be advantageous, inter alia, for example for a multilayered, in particular two-, three- or four-ply, fibrous web 309 or even if, for ecological and economic reasons, it is desired to mix a proportion of recycled material into the fibrous web 309.In this case, a fibrous web production plant 3 can preferably be designed with a plurality of, in particular two, three or four, dry forming apparatuses, wherein each individual dry forming apparatus is ideally assigned its own fibrous material processing plant. The corresponding number of dry forming devices can be arranged upstream of the dry forming device 4C shown in FIG. 2, preferably all dry forming devices deposit the defibrated fibre material on a common forming screen 41, wherein the following dry forming device then deposits the defibrated fibre material on the fibre laid previously on the forming screen. The basic remaining structure of the fiber web production and fiber material processing plant can be designed as illustrated, but it can also optionally be adapted to the processed fiber material in details such as, for example, the operating parameters.The low-water, in particular waterless, fiber material treatment contributes critically to the quality and properties of the dry-formed fibrous web 309 produced and to the overall balance of the production process with regard to economic and energy aspects.A great challenge here for production on an industrial scale is the use of bale product 200 as starting material or fiber material. For this purpose, a discontinuous process must be transformed into a continuous process, wherein the very high production quantities of several thousand tons of completely produced fibrous web 309 per year provide a particular challenge. For efficient and economically viable operation of the fibrous web production plant 3, a production speed of more than 300 m / min, in particular more than 400 m / min, preferably more than 500 m / min, is sought. Compared to the otherwise customary fibrous web production plants for producing a dry-formed fibrous web, this is at least more than twice to six times as high and the entire previously known fibrous material treatment and fibrous web production maintains a reliable and high-quality production process under these boundary conditions against new challenges.These high or industrial production quantities mean that the available fiber material 200 should ideally be stored as compactly as possible in order to reduce storage as far as possible. An important aspect in the low-water fiber material treatment is that the required volume of the treated fiber material 200 increases steadily until the final processing of the defibrated fiber material in the fiber web plant 3. The increase in volume can increase between the supplied starting material or the fiber material, in particular market pulp as bale product 200, up to the defibrated fiber material dissolved in the fiber / air stream, comprising individual fibers and / or fiber bundles upstream of the fibrous web production plant 3 or directly upstream of or in the dry forming device 4C, usually in the range of 30 000 to 50 000 times. As a result, stock keeping or intermediate storage of defibrated fibre material in the fibre material processing process is to be kept as low as possible and is to be provided only at decisive processing steps.A further aspect of the overall balance is to keep the supplied fiber material high in terms of its availability and low in terms of its costs. In current dry lay processes or dry forming processes, fluff virgin fiber pulp or "fluff pulp" is usually used for the most part in the form of roll goods for end products. The fluff pulp can be supplied directly and continuously regulated only to a fiberizing device and, as a result, a continuous mass flow with a small fluctuation width can already be supplied to the fiber web production plant.In comparison, in current wet-laying processes, an industry-standardized market virgin fiber pulp, usually in bale form, is usually used. This is also predominant with respect to the current world-wide market share of virgin fiber pulp in comparison to fluff pulp. Both types could also originate from the same production plant for virgin fiber pulp, but the market pulp has been produced in a significantly less expensive manner and is thus available in larger quantities and also at lower costs.As an important distinguishing feature, at least two further production steps have additionally been carried out in fluff pulp in comparison with market pulp. These lead on the one hand to a lower material density as a result of a higher proportion of air and / or a significantly lower fluctuation or tolerance range in the basis weight in the final, rolled fluff pulp compared to market pulp.Usually, in the case of fluff pulp in the form of roll stock, a major part of the fiber material treatment for the produced fibrous web is already shifted into the production process of the fluff pulp. The production of fluff pulp is more complex and complicated. Furthermore, the composition of the fluff pulp during its production can be adjusted with additives already for the production of the final fibrous web. The most important requirement for fluff pulp is a low tolerance of the mass distribution or the weight per unit area in comparison with the market pulp. This is necessary for the known fibrous web production processes in order to provide a continuous mass flow.Also usually added to the fluff pulp are additives, such as, for example, "debond agents", which facilitate the fiberization of the fiber material or the dissolution of the individual fibers among one another and counteract a renewed accumulation (agglomeration) of the individual fibers in the further production process; this is usually not the case in market pulp or is reduced to a minimum, since the lowest possible production costs are sought here.The term fluff pulp, fluff pulp or also fluff pulp must therefore be clearly distinguished from a market fresh fiber pulp or market pulp. The generic term of both types / types can be understood to mean virgin fiber pulp.Furthermore, the market pulp in bale form is distinguished by a smaller storage volume and better transportability or a higher density or concentration of fibers or a fiber quantity per cubic meter volume compared to the fluff pulp in roll form. This is due on the one hand to the presentation shape, for example a cubic bale compared to a cylindrical roll, and on the other hand to the lower material density of the fluff pulp itself.A bale of market pulp may consist of a plurality of pulp sheets stacked one above the other. This market pulp can be NBSK pulp, as is usually used for producing a paper, board or tissue web by wet process. The market pulp may have a material density between 800 kg / m 3 and 1,000 kg / m 3, in particular of around 920 kg / m 3, wherein the individual pulp sheets may have a thickness between 1.0 mm and 2.0 mm, in particular of approximately 1.5 mm.Alternatively, a bale can also consist of recycled material, for example pressed recycled material. In this case, the bale is roughly pre-comminuted as a whole of the at least one comminution device or with an optional further comminution device arranged upstream, so that the pre-comminuted recycled material corresponds substantially to the quantity of cellulose boards fed in.The generic term starting material or fiber material is used here for pulp-containing fiber material, in particular market pulp and / or recycling fibers.A particularly efficient recycling can be the direct reuse of so-called "machine waste", which originates from the present machine, in particular the fiber material processing plant and / or the fibrous web production plant itself. This very high-quality scrap from the machine can be fed directly back into the machine 1, for example the fiber material processing plant 2 and / or fiber web production plant 3. Alternatively, in the case of contamination, for example by additives, the machine waste can be processed again before it is fed back to the machine. This makes it possible to achieve a further improvement in the overall balance of the production process. An efficient configuration of this return can also represent a distinct inventive idea.Higher-order coupling and matching of the two production processes of the low-water fiber material treatment plant 2 and the fibrous web production plant 3 is an important feature for the production of a high-quality fibrous web 309 on an industrial scale. Both installations have a superordinate control and regulating device 60 which makes it possible to operate both installations in a manner coordinated with one another, in a controllable and regulable manner.The low-water fiber material treatment process or the fiber material treatment plant 2 is characterized by a stepwise comminution or fiberization 221, 222, 223 of the discontinuously fed starting material 200, wherein at the end of the low-water fiber material treatment process a last fiber / air stream 208 to 210 matched to the downstream fibrous web production plant 3, preferably comprising individual fibers and / or fiber bundles dissolved in air with a small proportion of nodes or free of nodes, is provided continuously with a maximum fluctuation or tolerance width in the range of + / - 4%, in particular + / - 2%, preferably less than + / - 1.5%, of the mass flow required in the fibrous web production plant 3.The fiber material processing plant 2 comprises at least two comminution or fiberizing devices, wherein at least one final fiberizing device 223 is provided.The discontinuously supplied starting material 200 is usually supplied in the form of substantially cubic or cuboidal bales 200, in particular cellulose, preferably market cellulose, comprising a plurality of stacked plates or recycled material, via conveying means to a first comminution device 221. As shown, for example, in FIG. 1, at least one bale 200 can be supplied to the at least one first comminution device 221, in particular a plurality of bales, in particular three bales are shown, are supplied in a row horizontally or vertically one behind the other, advantageously an approximately uniform supply of the bales has a positive effect on the comminution quality and the service life of the comminution device 221.The first comminution device 221 is designed in such a way that it can carry out a first comminution of the bales 200 into coarse chips, chips or so-called chips 201.The chips 201 produced by the comminution device 221 have a weight-to-circumference ratio of between 5 g / m and 10 g / m, preferably between 5.5 g / m and 8.7 g / m. A chip 201 resembles the shape of the scherbe of a broken glass sheet. It has a plurality of substantially rectilinearly extending edges which together give the shape of an irregular polygon. By summing the length of the individual edges, the circumference of the chip 201 is obtained. If, in addition, the weight of the chip 201 is also measured, the aforementioned weight-to-circumference ratio can be calculated easily. In the present exemplary embodiment, at least 50%, preferably at least 70%, further preferably at least 80%, of the chips 201 can weigh between 0.5 g and 1.0 g, preferably between 0.6 g and 0.9 g. The chips 201 are further distinguished in that their edges are free from plasticizing. Discoloration of the fibers or increased densification of the material in this area should not occur. Further, the average length of the fibers in the chips 201 should still correspond to more than 95% of the average length of the fibers in the original bale pulp 200.In an alternative embodiment, for example, the comminution device 221 is designed as a shredder 221, so that the shredder 221 comprises a rotor which is provided with projections and has a diameter of approximately 300 to 450 mm and which is operated at a rotational speed of between 500 and 800 revolutions per minute which is kept substantially constant. This advantageously allows the tips of the projections on the rotor to have a speed of approximately 12 m / s. The torque of the rotor is measured in operation and the measured quantity is used to control the speed at which the bale 200 is fed to the shredder 221.The chips 201 can then be supplied to a cleaning device 230, wherein any unwanted constituents still contained in the chips 201 so-called "rejects" such as, for example, metals, contaminants and / or packaging residues can be filtered out and cleaned chips 202 are present after the cleaning device 230, preferably embodied as a cyclone separator 230.These cleaned chips 202 can be temporarily stored in a storage device 240, preferably a bulk material container 240 or a silo 240. This is a larger storage unit 240, in a fiber material processing line or the fiber material processing plant 2.A "larger" store 240 is understood to mean that, likewise in individual components of the fiber material processing plant 2, due to their design or design, smaller "micro" stores can be provided or result, but these are not suitable for continuously supplying the fibrous web production plant 3 over a plurality of minutes up to a plurality of hours. The larger memory 240 enables, without renewed feeding of chips 201, a supply of the downstream installation over a specific period of time.Advantageously, the storage device 240 can be arranged after the cleaning 230 of the chips 201, wherein the volume increase of the fiber material can be kept as small as possible, and a maximum storage capacity of the storage device 240 of greater than or equal to 30 min, in particular greater than or equal to 60 min, preferably greater than or equal to 90 min, and less than or equal to 120 min of the production of the fibrous web manufacturing plant 3 can furthermore be provided.The size of the storage 240 can thus be configured depending on the produced weights per unit area and width of the fibrous web 309 and the production speeds of the fibrous web production plant 3. The embodiment of the memory 240 is designed to be geometrically optimized, so that a compact, low-air, volume-optimized storage of the cleaned chips 202 is made possible.In Fig. 1, a single stepwise defibrating line is shown downstream of the store 240 with a discharge device 241 and two successive defibrating devices 222, 223. Alternatively, a single storage 240 can also be provided to feed a plurality of, preferably two or three or four, parallel fiberizing lines. It is understood that in such an embodiment the discharge device 241 and the two consecutive defibrating devices 222, 223 will be present in the same number as defibrating lines.Alternatively, a conditioning device 260 or a conditioning of the fiber material can be provided after the cleaning device 230 of the chips 201 for the cleaned fiber material or the cleaned chips 202.An arrangement of the conditioning device 260 in front of the memory 240 is shown, but an arrangement of the conditioning device 260 in the memory 240 is also conceivable.The conditioning allows treatment of the fiber material, for example, a small amount of moisture can be supplied and / or removed; this can be advantageous in order to minimize or avoid dust formation and / or electrostatic charging. This also allows an explosion risk to be minimized.Conditioning may also be necessary, for example, depending on the climatic boundary conditions at the installation location or may be designed to be dependent on the seasons.In addition to water (moisture), additives can also be added to a conditioning system.If conditioning is provided, the means used for conditioning must be taken into account in the overall balance of the machine 1.The storage 240 can preferably be embodied as a vertical storage, in particular a vertical bulk material container or a vertical silo, wherein the weight force of the cleaned chips 202 can advantageously enable a slight compaction and thus the fiber / air mixture is concentrated to a higher level and forms chips 203 stored in the storage 240.Furthermore, at least one, preferably two or three or four, discharge device(s) 241 can be provided in the storage 240, which can enable continuous discharge of the stored chips 203.To assist the discharge of the stored chips 203 from the storage unit 240, a sixth air stream can be mixed in by a sixth air supply device 96 directly at the outlet of the storage unit 240 or after the discharge device 241, so that the stored chips 203 can be distributed and mixed in a first fiber / air stream 204 in a subsequent distribution channel or fiber / air stream transport system and thus transported to at least one comminution device 222, 223.Optionally, a first defibering device 222 may be arranged upstream of the last defibering device 223. As shown, the stored chips 203 are conveyed by the at least one discharge device 241 into the first defibering device 222 via a fiber / air flow conveying system.The first and last fiberizing device 222, 223 each comprise at least one rotating rotor with cutting elements arranged on the rotor circumference, which fiberizes a supplied fiber material. Furthermore, in the fiberizing device, at least one filter device, preferably a screen, is respectively included, which retains a fiber material fiberized by the rotor in the corresponding fiberizing device for such a time that the rotor with the cutting elements can fiberize the fiber material further until the fiberized fiber material can pass through the plurality of individual openings included in the filter device and emerge from the fiberizing device. The residence time of the fiber material in the defibrating device is measured from its entry into the defibrating device to its exit through the respective filter device of the defibrating device.The speed and diameter of the rotor determine the speeds at which the cutting elements can move and meet the fiber material.The first and last defibrating device 222, 223 can be embodied, for example, as a hammer mill, wherein the cutting elements are hammers in this embodiment.A first fiber / air stream 204, in particular comprising cleaned or stored chips 203, is fed to the first defibering device 222.The supplied fiber material contained in the first fiber / air stream 204 can be defibrated by the first defibrating device 222 until a first defibrated fiber material, comprising individual fibers and / or fiber bundles with individualized nodes, is formed.The first defibrated fiber material can now pass through the filter device and then exit the first defibrating device 222 as a second fiber / air stream. The first volume and mass flow of the second fiber / air flow 205 corresponds substantially to the volume flow of the first fiber / air flow 204.By "a volume flow corresponds substantially to another volume flow" is meant that slight deviations in the positive as well as negative direction due to possible leaks and leaks, for example due to bearings and fastenings, are conceivable, which make it possible for a small amount of air to be added to and / or escapes compared to the remaining contained air.By "a mass flow corresponds substantially to another mass flow or is constant" is meant that slight deviations in the negative direction due to possible leaks and leaks, for example due to bearings and fastenings, are conceivable, which make it possible for the slight mass, in particular fiber material, to be lost in the stream.Optionally, a fourth air feed 94 can be provided downstream of the first fiberizing device 222, which can increase the first volume flow of the second fiber / air flow 205 to a second volume flow of the second fiber / air flow 206. Thus, the discharge of the fiber material, comprising individual fibers and / or fiber bundles with individualized nodes, from the first fiberizing device 222 can be advantageously supported and the further transport to the next processing station can be improved.The second fiber / air stream can alternatively be supplied with its first volume flow 205 directly to the second fiberizing device 223.Optionally, a fifth air feed 95 can be provided upstream of the second fiberizing device 223, which can increase the first volume flow of the second fiber / air flow 205 to a third volume flow of the second fiber / air flow 207. Losses that may possibly occur in the preceding fiber material processing steps can thus advantageously be compensated for and improved fiberization in the second fiberizing device 223 can also be supported.Optionally, the first volume flow of the second fiber / air flow 205 can be supplied to a further fiber processing device 250 after exiting the first fiberizing device 222 and before entering the last fiberizing device 223.In the embodiment with a further fiber processing device 250, the first fiberized fiber material can be processed again; for example, conditioning and / or addition of additives is conceivable.Alternatively, in the embodiment, with a further fiber processing device 250 in the further fiber processing device 250, the first defibrated fiber material can be formed into a compacted fiber intermediate web.If a fiber intermediate web is formed, the individual fibers and / or fiber bundles comprised with individualized nodes of the second fiber / air stream 205 are separated from a large part of the air and are easily compacted, so that an intermediate web having a constant thickness and mass is formed. The thickness of the intermediate fiber web should be between 1 cm and 25 cm, in particular 2 cm to 15 cm, preferably between 4 cm to 10 cm, in order to achieve sufficient, but not too great, densification without the formation of additional fiber bundles with nodes.The intermediate fiber web can be regulated and controlled in terms of production speed and / or degree of compaction by the fiber processing device 250.For constant mass flow control, at least one means is included in the further fiber processing device 250 which controls and controls the intermediate web production in speed, thickness and compaction as a function of the requirements from the fibrous web production plant 3 via the higher-order control and regulating system 60.The majority of the previously separated air from the second fiber / air flow 205 can be conducted for the most part as a by-pass around the further fiber processing device 250 and fed back directly after or still in the further fiber processing device 250 and thus form a second fiber / air flow 206 with a third volume flow.Furthermore, the further fiber processing device 250 can be directly upstream of the last fiberizing device 223 and the intermediate fiber web and the previously separated air from the second fiber / air stream 205 and the fiber material can be supplied as a compacted intermediate web as a newly formed second fiber / air stream 207.Alternatively, a further comminution device can be included in the further fiber processing device 250, which is suitable for precomminuting the intermediate fiber web into uniform pieces. The further comminution device can be seen as a further means in order to achieve a regulation of a constant mass or volume flow for the following fibrous web production plant 3. The pre-comminuted pieces are then supplied with the previously separated air from the second fiber / air stream 205 as newly formed fiber / air stream 207 to the last fiberizing device 223.The last fiberizing device 223 defibers the first defibered fiber material of the supplied second fiber / air stream 207, comprising individual fibers and / or fiber bundles with individualized nodes, until only individual fibers and / or fiber bundles essentially free of nodes or with a smaller proportion of nodes form, which can then pass a filter device, in particular a screen device or a screen, comprised in the last fiberizing device 223 as the last defibered fiber material. The last defibrated fibre material exits the last defibrating device 223 as the last fibre / air stream 208.The rotor of the last defibrating device 223 is thereby operated at the same or higher speed than the rotor of the first defibrating device 222, this means that the speed of the cutting elements of the last defibrating device move and strike the first defibrated fiber material at the same or higher speed than the cutting elements of the first defibrating device 222. This leads to an advantageous reduction in the proportion of fiber bundles with nodes in the last defibrated fiber material in comparison to the first defibrated fiber material.According to the invention, at least one air feed 91 is provided downstream of the last fiberizing device 223, which increases a first volume flow of the last fiber / air flow 208. Losses that may possibly occur in the preceding fiber material processing steps can thus advantageously be compensated for and improved fiberization in the last fiberizing device 223 can also be supported.Furthermore, it is particularly advantageous with respect to the following dry forming device 4C, which can be operated at a more efficient operating point by the additional air with a higher second volume flow of the last fiber / air flow 209. By the additional air supply, the continuous and coherent fiber material processing process can be decoupled from the fiber web production process and thus an optimum operating point of the last fiberizing device 223 and the optimum operating point of the following dry forming device 4C are established.After the low-water treatment in the fiber material treatment plant 2 has taken place, the last defibered fiber material is fed to the fibrous web production plant 3 in a second volume flow 209 and thus leaves the fiber material treatment plant 2.The fibrous web production plant 3 illustrated in FIG. 2 is described below. The fibrous web production plant 3 or the fibrous web production process, in particular at production speeds of more than 300 m / min, comprises at least as essential features:• at least one dry forming device 4C,• at least one, preferably two, solidification device(s) 81, 83,• at least one application device for a fluid 71, 72, 73,• at least one drying device 110 or heating device 110, and• A reeling device 120.The fibrous web production plant 3 is suitable for producing an air laid fibrous web, in particular at production speeds of more than 300 m / min, the fibrous web production process in the fibrous web production plant 3 comprises at least as essential processes or process steps:• at least one dry forming process 4,• at least one, preferably two, solidification process(s) 8,• at least one process of application of a fluid 7,• at least one drying process 11 and• A rolling process 12.The fibrous web production plant 3 comprises a dry forming process 4 having at least one dry forming device 4C, preferably two or three or four dry forming devices, which can be supplied from a fibrous material processing plant 2 by a respective fiber / air stream 209 of defibrated fibrous material, which is preferably supplied on both sides.The at least one dry forming device 4C forms a flat, continuous fiber laid scrim 300 on a revolving support element, preferably a permeable forming belt 40 or forming screen 40, wherein the fiber material is for the most part removed from the supplied fiber / air stream 209. The forming belt 40 runs in the running direction 22 marked with an arrow.The last fiber / air stream 209 exiting from the fiber material processing plant 2 or the defibered fiber material 209 or the individual fibers and / or fiber bundles transported with the fiber / air stream substantially free of nodes 209 are guided directly into the at least one dry forming apparatus 4C of the downstream fibrous web manufacturing plant 3 and distributed uniformly transversely to the machine running direction MD of the fibrous web manufacturing plant 3 via further means included in the at least one dry forming apparatus 4C.The planar laid fiber fabric 300 formed from defibrated fiber material is then consolidated at least once, preferably twice or three times, to form a consolidated laid fiber fabric 305. The consolidation 8 of the laid fiber fabric 300 takes place stepwise in two or more consolidation processes. The at least one consolidation process 8 takes place in at least one, preferably first, consolidation device 81. in particular, in the case of a plurality of consolidation processes provided, the consolidation pressure and / or temperatures applied in the respective step increases in the transport direction of the laid fiber web or of the fibrous web in comparison with the previous step.After the dry forming device 4C, at least one application process 7 is provided by means of at least one, preferably first, application device 71 which applies or applies a fluid, preferably a water and / or a water-additive mixture, to the laid fiber fabric 300 and / or to the consolidated laid fiber fabric 305. The first application device 71 is preferably arranged in front of the at least one consolidation device 81 and applies a fluid to the laid fiber fabric 300After the at least one application device 71, the fibrous web is dried or heated. This drying 11 is carried out by a drying device 110, preferably a contactless and / or electrical drying device 110. The drying 11 is carried out below 350° C., in particular less than or equal to 250° C., preferably less than or equal to 100° C.In the case of the temperature specifications of drying and / or heating, the temperatures relate to the temperature of the heating elements used, the temperature acting on the fibrous web or the fibrous web or the temperature reached can be lower in this case and is dependent on the production speed and dimension of the drying or heating devices used. If the fiber lay temperature is referenced, this is explicitly stated.The produced fibrous web 309 is wound up by a winding device 120 at the end of the production process in a winding process 12.Alternatively, at least one of the consolidation devices 81, 83 can be designed with a strength-enhancing structuring device which makes it possible to introduce an advantageous increased strength-enhancing structuring into the fibre laid scrim 305. Advantageously, this allows an increased strength of the fibrous web to be achieved than only by consolidation. In addition, an optically appealing pattern can be introduced into the fibrous web through the structure.If a structuring is carried out in a consolidation step 8, for example in the case of a simultaneous consolidation and structuring in the at least one consolidation device, the press roller 811 can be embodied as a structured press roller 811 having a surface structure and / or the press element 812 can be embodied as a structured press element 812.In the case shown, with a first main consolidation device 81 which is arranged in a consolidation belt 41, the press roll 811 and the press element 812 can preferably be embodied with a smooth surface and the consolidation belt 41 can have a surface structure which can introduce structuring into the fibre laid scrim 300. The consolidation belt 41 runs in the running direction 22 marked with an arrowAfter the dry forming process 4, a pre-consolidation process can be provided which pre-consolidates the fibre web 300 with a pre-consolidation device 83 before it undergoes main consolidation in the at least one consolidation device 81.Furthermore, a second (main) solidification process can be carried out with a second solidification device arranged downstream of the at least one first solidification device 81. The second consolidation device can advantageously form a consolidation nip comprising a press roll and a press element, free of a further support element such as a consolidation belt.Furthermore, the second consolidation device can also be designed as a structuring device, in which case the press roller is advantageously designed as a structured press roller having a surface structure and / or the press element is designed as a structured press element.In an alternative embodiment, a second air stream, preferably fiber / air stream, can be supplied to the last fiber / air stream with a second volume flow 209 directly upstream of and / or in the at least one dry forming device 4C with a second air supply device 92 and a last fiber / air stream with a third volume flow 210 can be formed. For a further optimisation of the decoupling of the forming process from the last fiberizing step, a second air supply device 92 can be arranged before the dry forming device 4C. By means of the second air supply 92, further air can be supplied to the first 208 or second 209 volume flow of the last fiber / air flow. Alternatively, the further air can be supplied to the second air supply device 92, for example from the exhaust air of the vacuum boxes 31, 32 from the fiber web recovery process, which receives, for example, a certain proportion of waste fibers or machine waste. The supplied air can also be supplied in the second air supply device from a suction device, for example a border strip suction device 50, a tail strip cutting device 55 and / or also from an air filter system of the machine shop.Furthermore, an optional combination of the sources for a second air supply is conceivable.In a further alternative embodiment, a third air stream, preferably fiber / air stream, can be supplied to the last fiber / air stream in the dry forming apparatus 4C by a third air feed 93, which can form the last fiber / air stream with a fourth volume stream 211. The third air supply 94 is preferably supplied for the most part directly from a suction device 30 of the corresponding dry forming device 4C. This enables an energy-optimized very short cycle of the large quantities of air required in the dry forming process 4. The amounts of air required in the dry forming process 4 or within the dry forming apparatus 4C are 10 times higher than the amounts which can be achieved from the last fiber / air stream exiting at a first volume flow from the last fiberizing apparatus.Advantageously, the main portion of the required volume flow for a dry forming process 4 can be supplied in a short, efficient recirculation circuit of the dry forming device 4C itself. This enables a reduction in the sizes of the required components.In an embodiment with a second 92 and / or third air supply 93, a fiber / air stream with a small proportion of machine waste fibers can preferably be supplied instead of a pure air stream. Returning the machine waste at these points can represent a separate inventive idea.The individual fibers and / or fiber bundles contained in the last fiber / air stream, substantially free of nodes, are deposited in the dry forming device 4C, preferably partially by the weight force, onto a revolving, permeable forming belt 40 and form a flat laid fiber scrim 300.The dry forming process 4 in the at least one dry forming apparatus 4C may be controlled and regulated by at least one included control and regulation means.Furthermore, the dry forming device 4C can comprise a suction device 30, preferably a vacuum box, which can assist the deposition of the individual fibers 209 on the permeable forming belt 40 and / or can control it as further control and regulating means.Furthermore, the laid fiber fabric 300 emerging from the dry forming apparatus 4C on the forming belt 40 can be detected by a measuring apparatus 61 with regard to relevant laid fiber fabric parameters such as thickness, distribution and formation. Preferably, a mass measuring device 61 extending in the transverse direction CD can be provided, which detects the formed fiber laid scrim in its mass distribution or basis weight distribution. These parameters can be used directly via the superordinate control and regulating device 60 as a control and regulating variable in the production quantity of the fiber material to be chopped of the fiber material processing plant 2, as well as in the control and regulating means included in the dry forming device 4C and preferably in the suction device 30, and can be matched to one another.Furthermore, immediately after leaving the dry forming device 4C, the laid fiber fabric 300 can, by means of a suction device 50 arranged in the transverse direction CD, control and specifically suck off excess fibers in the z direction (thickness) over the entire transverse direction CD from the surface of the laid fiber fabric, so that a homogeneous weight per unit area distribution in the CD and MD direction can be established.Alternatively, the suction device 50 can comprise a both-sided edge strip suction 50 or can even be configured only as a both-sided edge strip suction 50. The edge strip suction 50 can be sucked off in a targeted manner from the edge regions of the laid fiber fabric 300 which often vary very greatly in thickness or weight per unit area and differ from the main or central region of the laid fiber fabric 300.Advantageously, this edge strip suction 50 can be used to return fresh machine waste or defibrated fiber material, which is still contaminated without additives or chemicals, directly to the fiber material processing plant 2 or to the dry forming process 4 directly after the dry forming device 4C, which has a positive effect on the overall balance of the machine.Furthermore advantageously, a clean edge of the fibrous web 309 can thereby be produced, which can make a further edge trimming before a final roll-up device 12 of the final fibrous web 309 unnecessary.Furthermore, a machine waste originating from the fibrous web production plant 3, for example the above-explained edge trimming or else individual fibers and / or fiber bundles which are filtered from the ambient air and are not deposited, can preferably be recycled or recovered again and, for example, fed back into the fibrous material processing plant 2 at a suitable location or else fed back directly upstream of and / or into the dry forming apparatus 4C. This is particularly advantageous if the machine waste still contains no additives and corresponds qualitatively substantially to the defibrated fiber material.Machine waste is understood to mean that during a production process of the fibrous web 309, either defibrated fibre material can form in clean or contaminated or defibrated fibre material contaminated by chemicals or additives. Both types of machine waste can ideally be appropriately processed directly via a feedback system and fed back to the production process. An improved recirculation system may also represent a distinct inventive concept.In an embodiment with a first application device 71, it is advantageous if the first application device 71 is arranged before the at least one solidification process 8 or the first solidification device 81. Furthermore, three application processes 7 can be provided after the dry forming device 4C. As shown in FIG. 2, a first application device 71, a second application device 72 and a third application device 73 can be provided. The first application device 71 can be arranged before the at least one solidification process 8 or the at least one, preferably first, solidification device 81.The second application device 72 and third application device 73 can be arranged after the at least one solidification process 8 or the at least one, preferably first, solidification device 81.Furthermore, at least one consolidation device 81, 83 is provided downstream of the dry-forming device 4C, which consolidation device can consolidate and / or heat and / or structure the fibre laid scrim 300.In an alternative embodiment, it can also be provided that two, three or four consolidation devices are arranged, which consolidate and / or structure and / or heat the laid fiber fabric or the fibrous web successively.Furthermore, it can be provided that in the case of a plurality of consolidation apparatuses, for example a presolidifier 83, a first consolidation apparatus 81 and / or a last consolidation apparatus, the pressures or line loads applied for consolidation of the laid scrim from the presolidifier 83 are lower than the line loads in the first consolidation apparatus 81.The individual consolidation gaps or press gaps or press nips can be formed in each case by at least two press rolls or else be combined in a multiple press roll arrangement, wherein one, two or three consolidation gaps can be formed in combination with the same press rolls. The consolidation devices can also comprise further support elements, for example a forming belt 40 or a consolidation belt 41, which can be guided through the consolidation gap or press gap.The application devices 71, 72, 73 are preferably designed as nozzle applicators which can spray the fluid 70 in the form of a spray jet as fluid droplets 70 onto the fiber scrim 300, 305.Alternatively, the application devices can also be designed such that the fluid is applied in the form of droplets, foam, mist or vapor.Alternatively, a curtain applicator or a roller applicator can also be provided, wherein the roller applicator can advantageously be integrated into a consolidation device 81, 82 and coated with a fluid via an application means, for example the press roller 811, which fluid is then transferred to the fiber laid scrim 300 in the following pres nip.Furthermore, in an alternative embodiment, a pre-consolidation device 83 can be arranged after the dry-forming device 4C and still before the first application device 71.As shown in FIG. 2, during drying 11, the fibrous web can be transported through the drying device 110 by the drying device 110 with a support element, preferably a drying belt 42 or a drying wire 42, or else unsupported, i.e. free of a support element. The drying belt 42 shown runs in the running direction 22 marked with an arrow.Further, the non-contact drying device 110 may be configured as, for example, a hot air drying device, a through-flow drying hood, a TAD drying device, or an infrared drying device. Preferably, in all embodiments, an electric heating of the drying device 110 can be provided.Advantageously, contactless drying 11 allows the properties of the fibrous web 309 to be adjusted and maintained exactly with regard to its thickness, its feel properties and its absorbency.Due to the low total moisture contents in the illustrated dry laying method, the length of the drying device 110 in the machine direction MD can be kept very compact in comparison to the usual drying sections from the wet laying methods and thus advantageously the overall length of the fibrous web manufacturing plant 3 and infrastructure costs can be significantly reduced. Compared with the conventional dry forming processes, too, the further reduced total amount of moisture-increasing fluids used, in particular water and water-additive mixtures, results in an advantageous reduction in the required dry energy.Another important constituent for decarbonization is not only the reduction of the total energy used, but also the execution of the otherwise customary fossil-heated apparatuses with efficient electrical heating. This enables the use of electrical energy produced "regeneratively" and thus forms an important step to form a fibrous web 309 produced in neutral CO2.At least one further heating process can be provided, which heats or heats the laid laid laid fiber scrim 300 or the consolidated fiber scrim 305 upstream of the drying device 110.The at least one further heating process can be integrated, for example, into one of the consolidation devices 81, 83 by heating the press roller provided for consolidation and / or the press element.Alternatively, the at least one further heating process can be provided directly before and / or after the at least one solidification process 8 by means of at least one further heating device.In a further alternative, the at least one further heating process can be provided directly before and / or after an application step 71, 72, 73 by means of at least one further heating device.In all embodiments of the at least one further heating process, heating below 200° C., in particular less than or equal to 150° C., preferably less than or equal to 100° C., can be provided. This is advantageous since the further heating process, for example after a first application step 71, assists the applied fluid, preferably water or a water-additive mixture, in its depth of penetration into and in its distribution in the laid fiber fabric 300, which can simultaneously have an effect by a downstream, more efficient consolidation and / or structuring.In particular, it can be advantageous if the laid fiber fabric in the at least one heating device reaches a laid fiber fabric temperature of not more than 100° C., preferably less than 80° C., before the last drying device 110. It is understood that the temperatures of the heating devices or heating elements are to be adjusted to the achievable final temperature in the fiber scrim depending on the fiber web manufacturing plant parameters.The first application device 71 can be arranged directly in front of the at least one, preferably first, solidification device 81 and apply a fluid.Further, the first application device 71 may apply water using normal or distilled water. Normal and distilled water means that the water is free of artificial or chemical additives. Alternatively, it can also be provided that the first application device 71 applies a water-additive mixture. If a water-additive mixture is applied to the laid fiber fabric 300 before consolidation 8, the additive is selected from the group of dry strength agents, for example a starch, to increase the strength in a dry state of the fibrous web 309 produced. The dry strength agents are also suitable for application before consolidation 8, since they have a lower tendency to adhere, such as adhesives or wet strength agents.Furthermore, as shown in FIG. 2, a first, second and third application device 71, 72, 73 can be provided. For uniform application, it may be advantageous if at least one of the three application devices is arranged on an opposite laid-open fibre side; preferably, the second and third application devices are arranged on the opposite laid-open fibre side.Furthermore, the second and third application devices 72, 73 can apply a water or a water-additive mixture to the laid fiber scrim. Preferably, the second and third application devices 72, 73 are arranged after the last solidification device and apply a water-additive mixture, wherein the water-additive mixture comprises an additive from the group of the adhesives or wet strength agents.Furthermore, the application devices 71, 72, 73 can be designed in such a way that the laid fiber fabric 300 can be wetted with the fluid in a planar manner. Here, "flat" is understood to mean that the fluid is applied substantially homogeneously over the entire width or over the entire transverse direction CD of the laid fiber fabric.Furthermore, in the case of the first, second and third application devices 71, 72, 73 a vacuum box 31 can be arranged on the respective opposite side, which is to the wetting side of the laid fiber web 300, which vacuum box draws in ambient air through the laid fiber web 300 and a permeable support element 40, 41, 42 on which the laid fiber web 300 is supported by a vacuum applied, preferably during application.This can advantageously allow a greater penetration depth of the applied fluid into the fiber scrim 300 during the application of a fluid or a control of the application quantities in the transverse direction CD and / or the machine direction MD.Optionally, at least one moisture measuring device 63 can be included in the fibrous web production plant 3, which can measure the moisture contents or the applied fluids on or in the fibrous laid scrim 300, 305 or the fibrous web 309.Furthermore, the at least one humidity measuring device 63 can be stationary or traversing.Furthermore, the moisture measuring device 63 can be arranged in such a way that it can measure before and / or after the drying device 110 and / or before and / or after the at least one, preferably first, second and / or third, application device 71, 72, 73.Further, moisture measuring device 63 may also be suitable for measuring other fibrous web properties such as mass, thickness, formation, opacity or other properties.List of reference characters1 Machine 2 Fiber material processing plant 3 Fiber web manufacturing plant 4 Dry forming process 4C Dry forming device 7 Application process 8 Consolidation process 10 Drying process 12 Reeling process 22 Running direction of the support elements 30 Suction device of the dry forming device 31 Vacuum box - application device 40 Forming belt 41 Consolidation belt 42 Drying belt 50 Suction device, Preferably, edge strip suction 55 tail strip cutting device 60 control and regulating device 61 mass distribution measuring device 63 moisture measuring device 71 first application device 72 second application device 73 third application device 81 first consolidation device 811 pressing roller 812 pressing element 83 pre-consolidation device 91 air supply device 92 second air supply device 93 third air supply device 94 fourth air supply device 95 fifth air supply device 96 sixth air supply device 110 drying device 120 rolling device 200 bale product 201 comminuted bale product or "chips" 202 cleaned chips 203, interposed chips 204 first fiber / air stream with a comminuted fiber material 205 second fiber / air stream with a first defibrated fiber material 206 second fiber / air stream after a fiber processing device 207 second fiber / air stream before entering the last defibrating device 208 last fiber / air stream with a second fiber The invention relates to a fiberized fibrous material having a first volume flow 209 of last fiber / air flow with additionally supplied air and a second volume flow 210 of last fiber / air flow with a third volume flow 211 of last fiber / air flow with a fourth volume flow 221 of first comminution device 222 of first fiberizing device 223 of last fiberizing device 230 of cleaning device 240 of storage 241 of discharge device 250 of fiber processing device 260 of conditioning device 300 of fiber laid 305 of consolidated fiber laid 309 of fibrous web MD of machine direction CD of machine transverse direction z of vertical direction

Claims

Method for producing an air-laid fibrous web (309), in particular a dry-formed paper, board or tissue web or a nonwoven web, from a, in particular bale- or plate-shaped, fibre material (200), in which the fibre material (200) - in a conditioning process is conditioned to form a defibered fibre material (209) with low water content, preferably without water; - in a dry-forming process a planar fibre web (300) is formed from the defibered fibre material (209) in a forming device (4C) by means of an air flow; - in a consolidation process the planar fibre web (300) is consolidated by applying pressure and / or temperature to the fibrous web (309); wherein, in the treatment process a), the fiber material (200) is comminuted in at least one comminution device (221) to individual, chip-shaped fiber material (201, 202, 203, 204); and b) thereafter, in at least one comminution device (222, 223), the individual, chip-shaped fiber material (201, 202, 203, 204) is further processed in stages to fiberized fiber material (205, 206, 207, 208 209); and the fiber material is transported as a fiber / air stream via the treatment process and up to the dry forming process; wherein at least one air supply device (91) is provided between a last fiber / air stream, the at least one fiberizing device (223), in the transport direction of the fiber / air stream, and the forming device (4C), by means of which air is supplied to the last fiber / air stream (208) exiting the last fiberizing device (223) before it enters the forming device (4C), characterized in that the additionally supplied air increases the last fiber / air stream (208) exiting with a first volume stream before it enters the forming device (4C) to a last fiber / air stream (209) with a second volume stream by a factor greater than or equal to 2, preferably 2.25, particularly preferably 2.50.Method according to claim 1, characterised in that a volume flow of the fibre / air flow (207) through the last of the at least one defibering device (223), preferably and a first defibering device (222), is kept constant or increased.Method according to at least one of the preceding claims, characterized in that a volume flow of the additionally supplied air is set in such a way that a negative pressure in and / or directly after the at least one last fiberizing device (223) of more than 4 kPa, in particular more than 5 kPa, preferably more than 7 kPa, is set.Method according to at least one of the preceding claims, characterized in that a second air supply device (92), which is arranged downstream of the at least one air supply device (91), is provided directly upstream of the forming device (4C), by means of which second air is supplied to the last fiber / air stream (209) increased to a second volume flow, in particular is supplied by an exhaust air stream from the dry forming process (4), preferably is supplied by at least one fiber / exhaust air stream from a suction box (31, 32) and / or an edge suction device (50) and / or a transfer tail cutting device (55), wherein the second air supply device (92) increases the second volume flow of the last fiber / air stream (209) to a third volume flow of the last fiber / air stream (210) by a factor greater than or equal to 1.3, in particular greater than or equal to 1.5, preferably less than or equal to 2.Method according to at least one of the preceding claims, characterized in that a third air supply device (93) is provided, which is arranged downstream of the at least one air supply device (91) and / or a second air supply device (92), by means of which the last fiber / air stream entering the forming device (4C) with a second (209) or third (210) volume flow is increased to a fourth volume flow (211) by a factor greater than or equal to 3, in particular greater than or equal to 3.5, particularly preferably greater than or equal to 4.0, preferably less than or equal to 5.Method according to at least one of the preceding claims, characterized in that a first fiberizing device (222) is provided, which is arranged upstream of the last fiberizing device (223) in the transport direction of the fiber / air stream.Method according to claim 6 characterised in that a fourth air supply device (94) is provided, which is arranged downstream of the first defibering device (222), by means of which additional air is supplied to a second fibre / air stream (205) emerging from the first defibering device (222).Method according to Claim 1 and / or 6, characterized in that at least one fifth air feed (95) is provided, which is arranged upstream of the last defibrating device (223) and / or of the first defibrating device (222), by means of which additional air is fed to a third fiber / air stream (206) entering the last defibrating device (223) before the entry and / or additional air is fed to a first fiber / air stream (204) entering the first defibrating device (222) before the entry, in particular from singled, chip-shaped fibre material.Method according to at least one of the preceding claims, characterized in that a mass flow of the fibre material in the fibre / air flow before (207) and after (208) the at least one last fiberizing device (223), preferably up to the forming device (4C), is kept substantially constant.Method according to claim 6, characterised in that between the first defibering device (222) and the last defibering device (223) a compacted intermediate web (250) of individual fibres and / or fibre bundles with individualized nodes is formed from the first defibered material (205), and that the intermediate web (250) is fed to the last defibering device (223) directly or in pre-comminuted form.Machine (1) for producing an air laid fibrous web (309), in particular a dry formed paper, board or tissue web or a nonwoven web, from a, in particular bale- or plate-shaped, fibrous material (200), in particular for carrying out the method according to claim 1, comprising: - a low-water fibrous material processing plant (2); and - a fibrous web production plant (3); wherein the low-water fibrous material processing plant (2) further comprises: - at least one comminution device (221); and - at least one last comminution device (222, 223); and - a fiber / air flow transport system connectable to the fibrous web production plant (3); wherein the fibrous web production plant (3) further comprises: - at least one forming device (4C); and - at least one consolidation device (81, 83); and - a reeling device (120); wherein at least one air supply device (91) is included between the at least one defibrating device (223) and the forming device (4C), characterized in that the at least one air supply device (91) is set in such a way that air is additionally supplied to the last fiber / air stream (208), which exits with a first volume flow, before it enters the forming device (4C), and is increased by a factor greater than or equal to 2, preferably 2.25, particularly preferably 2.50, to a last fiber / air stream (209) with a second volume flow.Machine (1) according to claim 11, characterised in that a second air supply device (92) is provided directly upstream of a dry forming device (4C), which is arranged downstream of the at least one air supply device (91).Machine (1) according to Claim 11 and / or 12, characterized in that a third air supply device (93) is provided, which is arranged downstream of the at least one air supply device (91) and / or of the second air supply device (92).

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