EP3740614A1

EP3740614A1 - Method and device for producing a fiber mat

Info

Publication number: EP3740614A1
Application number: EP18808249.9A
Authority: EP
Inventors: Dominik FRANKENREITER; Alexander GLONING; Thomas Martin
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2018-01-15
Filing date: 2018-11-16
Publication date: 2020-11-25
Also published as: CN111601927A; CN111601927B; EP4345208A2; WO2019137667A1

Abstract

The invention relates to a method for producing a fiber mat, having the following steps: collecting and providing the fibrous material-containing recycling material; treating the fibrous material-containing recycling material in an airflow in order to form raw material containing individual fibers and/or fiber bundles using little water; forming the individual fibers and/or fiber bundles (12) in the airflow into a flat fiber mat (10) using a dry forming process; applying water to the fibers of the formed fiber mat (10); and solidifying the formed fiber mat (10); wherein the fiber mat (10) is pressed in a solidification step e) between two support elements (9a, 9b), each of which has a contact surface facing the fiber mat (10), in a horizontal manner for a pressing time of less than 1 s, in particular less than 0.8 s, preferably less than 0.5 s.

Description

METHOD AND DEVICE FOR PRODUCING A FIBER MAT

The invention relates to a method for producing a fiber mat, and to an apparatus for carrying out the method and to a fiber mat produced by the method.

In the known papermaking the processed in a stock preparation natural fibers such as pulp fibers are mixed with water to form a fiber suspension and applied uniformly on a dewatering screen a forming unit, mechanically dehydrated there and led the fibrous web formed for further mechanical dewatering through a press and then thermally dried , The aqueous pulp suspension has very small substance densities, for example, 1%, that is, the fibers are mixed with a lot of water. This is necessary for a homogeneous mixing of the fibers with water and a prerequisite for the formation of a uniform fibrous web. Also, the water enables bonding between the fibers through hydrogen bonding, thereby achieving a fibrous web having good mechanical strength. These processes require a high expenditure on equipment and energy. In particular, the thermal drying of the fibrous web from about 50% dry content after the press to more than 90% final dry content requires large drying sections and large amounts of thermal energy.

Document DE2314893A proposes a method for producing a fibrous web without using large volumes of water. In this case, a fleece is made from substantially dry fibers and moistened with water to below the Quellfeuchtigkeitsaufhahme. In a further step, the moistened fleece is passed through a heated pressure zone. The pressure zone is designed so that the applied water has sufficient time to penetrate the fibers to increase the compliance of the fibers and to provide the prerequisite for entering the chemical bond portions between the fibers.

The object of the invention is to specify an improved method and an improved device for the economic production of a fiber mat with lower investment and energy costs. The object is solved by features of claim 1. It is a process for producing a fiber mat, which is particularly suitable for use in the production of packaging board or fibrous structural elements, from a fibrous recycling goods, Wehpappenab cases and / or Kartonab cases and / or waste paper and / or paper or cardboard waste from the Papermaking, proposed. The method comprises the following steps:

a. Collecting and providing the fibrous recycled goods;

b. Low-water treatment of fiber-containing recycled goods in the airstream to produce commodities comprising individual fibers and / or fiber bundles;

c. Forming the Einzelfasem and / or fiber bundles in air flow to a flat fiber mat by a Trockenformgemngsverfahren;

d. Applying water to the fibers of the formed fiber mat;

e. Solidifying the formed fiber mat;

wherein provision is made for the fiber mat in the solidification step e) to be pressed between two support elements having a contact surface facing the fiber mat, with a pressing time of less than 1 s, in particular less than 0.8 s, preferably less than 0.5 s.

The method according to the invention enables the economic production of a fiber mat which at least partially comprises natural fiber material. The recycled fabric may comprise at least one fiber material from the pulp, wood pulp, cotton, annual plants such as bamboo, straw, grass, hemp. For the processing of recycled goods, only a small amount of additional water is required. For the treatment, the amount of water already contained in the air-dry recycled goods may be sufficient. The dry content of the collected air-dry recycled fabric is usually 1% to 10%.

The inventors have recognized that a short press pulse for the consolidation of the fibers of the fiber mat is sufficient for sufficient mechanical strength. At the same time a good quality in terms of performance characteristics of the fiber mat can be achieved with little effort.

In one possible embodiment, the recycled product is comminuted in the preparation step, freed of impurities and in individual fibers and / or fiber bundles, for example, in Hochkonsistenzrefmem or in Querstromzerfaserem or disassembled in mills. Subsequently, a cleaning of the fraction of the individual fibers and / or fiber bundles can take place. In this step, further impurities are removed.

The formation of the individual fibers and / or the fiber bundles in the stream of flow into a flat fiber mat by a dry forming process requires only a fraction of the energy of the known papermaking processes. The inventors have found that a short pressing time in the solidification step is sufficient for sufficient bonding between the individual fibers and / or fiber bundles to form a fiber mat. At the same time penetration of the applied water into the Einzelfasem and / or fiber bundles is made difficult by the short pressing time. However, this has proven to be an advantage in terms of lower energy requirements. The water that has penetrated into the fibers can only be removed with thermal energy. The thermal drying effort for drying the fiber mat is thus comparable to that for a conventionally produced paper web after the press section of a paper machine. For a fiber mat produced by the process of the invention, however, the thermal drying effort is reduced or avoided altogether, since the applied water is largely only on the surface of the Einzelfasem and / or the fiber bundles.

In a practical embodiment, the fiber mat is pressed with a pressing time of more than 0.0lms, in particular of more than 0, lms, preferably of more than lms. This favors the mutual bonding of the individual fibers and / or fiber bundles at the points of contact. The adhesive bonding capacity of the individual fibers and / or fiber bundles is thereby used to a significant extent, in particular by the formation of hydrogen bonds. The resulting fiber network of the fiber mat thus receives a high strength.

The solidification step e) preferably follows the application step d) after a maximum of 20 s, in particular after a maximum of 10 s, preferably after a maximum of 5 s. This prevents the penetration of the applied water into the interior of the Einzelfasem and / or fiber bundles before the solidification step e), whereby the cost of the thermal drying of the fiber mat is reduced or even avoided. In an advantageous embodiment, the solidification step e) is carried out so that the fiber mat then has a solids content of more than 50%, in particular more than 70%, preferably more than 80%, particularly preferably more than 90%. This can be influenced, for example, by heating the fiber mat in the solidification step.

In a practical case, the treatment step b) is carried out with fibers, or with recycled goods with a dry content of more than 50%, in particular more than 70% and preferably of more than 80%. In particular, the recycling center can also be air-dry.

In one possible embodiment of the forming step c), a very loose layer of individual fibers and / or fiber bundles is produced. In the forming step c), a flat fiber mat with a specific volume of more than 12 cm ³ / g, in particular more than 20 cm ³ / g, preferably more than 25 cm ³ / g is placed. This has a favorable effect on the homogeneous distribution of Einzelfasem and / or fiber bundles in the volume of the fiber mat and on the other to the effect and uniformity of the distribution of the applied water. As a result, a fiber mat with a homogeneous distribution of strength can be achieved when using minimal amount of water.

In a practical case, after the forming step c), the flat fiber mat is precompressed, in particular to a value of more than 50%, preferably more than 70% of the specific volume of the fiber mat laid in the forming step e). In other words, the compression is carried out so that the thickness of the laid fiber mat immediately after compression is at least 50%, preferably at least 70% of the thickness of the laid fiber mat after the forming step and before the compression step. This improves the stability of the laid fiber mat. This is especially true in a continuous production of the fiber mat. The fiber mat is thus insensitive to occurring Fuftströmungen.

Advantageously, in the application step d), the laid fiber mat with an amount of water in the range between 5% and 50%, in particular between 5% and 40%, preferably between 5% and 30% of the mass of the laid fiber mat acted upon. It is also conceivable amounts of water between 5% and 20% or between 5% and 10%. This has an energetically favorable effect. One possibility for applying the water is that in the application step d) the top and / or the underside of the laid fiber mat is sprayed with drops of water and advantageously the drops of water have a drop size in the diameter of less than or equal to 3 mm, in particular less than or equal to 2 mm, preferably of less than or equal to 1 mm. This improves the rate of wetting of the surfaces of the individual fibers and / or fiber bundles of the laid fiber mat.

In the application step d), water is preferably applied by means of an application element which can be brought into contact with the upper side and / or the underside of the laid fiber mat in a contact region.

The applicator element can be provided, at least in the contact area, with a porous, preferably compressible layer for storing and dispensing water. The layer may for example be designed as a sponge. The sponge may be applied to a harder carrier element.

In a further embodiment, the application element is provided, at least in the contact area, with a structured surface for storing and dispensing water.

It is also possible that the applicator element is formed by at least one support element.

The applicator element is preferably designed as a roll in the continuous production process or as a stamp in the discontinuous production process.

In a practical case, in the application step d), the top and / or the underside of the laid fiber mat can be subjected to steam.

The temperature of the steam is preferably adjusted to the temperature of the fiber mat so that the steam condenses on impact with the top and / or bottom of the laid fiber mat.

In one possible development, the steam is applied to the fiber mat in such a way that drops of water on the top and / or on the underside of the laid fiber mat be formed with a droplet size in the diameter of less than or equal to 3 mm, in particular of less than or equal to 2mm, preferably less than or equal to lmm.

The water can also be applied in the form of steam, which is preferably saturated at a temperature above the temperature of the fiber mat, on the top and / or bottom of the fiber mat.

The water can also be applied in the form of steam, which is preferably saturated at a temperature above the temperature of the fiber mat, wherein the fiber mat is flowed through by the steam. Preferably, the vapor condenses on the Einzelfasem and / or the fiber bundle of the fiber mat. As a result, the water can be very evenly distributed in the fiber mat.

In an advantageous embodiment, at least one support element in the solidification step e) is formed such that the fiber mat is fully or zonelessly supported over the entire surface. Due to the full-area or zone-wide full-area support the contact is strengthened in the solidification step by the pressing at the contact points of the contacting fibers and thus improves the solidification. Zone-wide support generates support zones in the zones. It has an advantageous effect in the production of, for example, tissue paper. The fiber mat is pressed and compacted in the support zones, so that a solidification is achieved there, while not or less pressed or compressed between the support zones. This creates areas with a larger specific volume between the support zones. These areas have an advantageous effect when using tissue papers due to a higher water absorption and higher fluffiness.

Preferably, at least one support element in the solidification step e) is made permeable or impermeable.

The contact surface of at least one support element is preferably made smooth for smoothing or with a structure for structuring or zone-wise full-surface solidification of the fiber mat. In this case, the structure in its dimensions, in particular the structure depth and the distance of the structure peaks, designed so that the fiber mat is supported over the entire surface. Bridging the fiber mat between Structure tips are avoided. The full-surface support causes a uniform formation of strength in the area of the contact surface.

For heating the fiber mat preferably at least one support element is heated directly or indirectly, preferably to a temperature between 20 ° C and 300 ° C. As a result, the adhesive bond between the individual fibers and / or the fiber bundle can be required and the dry content of the fiber mat can be influenced after the solidification step.

In a practical embodiment, at least one support element is designed as a band. The support element may be guided around one or more rollers.

A running as a band support member may have support zones, so that the fiber mat is supported zone-wise over the entire surface. This can be a film or a membrane designed as a band. The band is permeable in this example and has openings, holes or the like in the thickness direction. The lying between the openings Fandflächen form the support zones. The Fandflächen themselves can have a structuring. The diameters of the openings may range between 0.1 mm and less than 3 mm. The distance between adjacent openings is preferably in the range of 0.3 mm to 3 mm.

In an advantageous embodiment, the openings of the band can be produced by drilling by means of fiber. This allows economical production of small openings.

In a possible further development, the support element is formed as a band of a belt calender and the material of the belt preferably comprises metal or plastic or composite material.

Further, it may be advantageous if the band designed as a supporting element disposed on the side facing away from the fiber mat pressing member for pressing the fiber mat is assigned, wherein the pressing member may be designed as a roller, a shoe roll or a belt press.

It is also possible if at least one support element is designed as a roller, for example a press roll, for pressing the fiber mat. The roll surface can for Smoothing of the fiber mat can be performed smoothly or with a structure for structuring the fiber mat.

Preferably, in the forming step c) the fiber mat is formed on a preferably permeable forming belt, in particular on a woven forming belt. The Formierband can be permeable to air or permeable to water. As a result, the filing of the fiber mat can be stabilized. In addition, the Formierband be designed so that an electrostatic charge can be. This stabilizes the filing of the individual fibers and / or fiber bundles on the forming belt.

In an advantageous embodiment variant, the forming belt is formed by a support element. It is advantageous if the solidification step e) is carried out on the support element. This allows a process in a compact and cost-effective design.

In one possible development, the laid fiber mat is transferred from the permeable forming belt to a support element. This allows both a vote of the execution of the forming belt to the specific requirements of the forming step as well as a vote of the execution of the support element to the specific requirements of the solidification step.

The support member may be electrostatically charged to assist in particular the transfer of the fiber mat from the forming belt to the support member.

Preferably, the flat fiber mat is produced endlessly. This continuous production process is particularly advantageous when the fiber mat is used as a packaging board.

However, it is also conceivable if the flat fiber mat is produced piecewise. In this case, the pieces of the fiber mat individually produced in a discontinuous process may be a final product or processed into a final product. For example, boxes can be made from the individual pieces. In a discontinuous process, the sheet-like fiber mat can be formed in a three-dimensional forming mold to produce a three-dimensional product. Three-dimensional products may be boxes, boxes, etc. or parts thereof.

According to the invention, the object is also achieved by a device for carrying out the method according to claim 1 for producing a fiber mat, which is particularly suitable for use in the production of packaging board or fiber-containing construction elements, from a fibrous recycling goods, Wehpappenab cases and / or waste cardboard and / or waste paper and / or paper or cardboard waste from papermaking, with a treatment plant for the low-water treatment of fiber-containing recycled goods in the air stream to raw material which comprises Einzelfasem and / or fiber bundles; and with a dry-forming device for forming the individual fibers and / or fiber bundles in air flow to a flat fiber mat, and with a moistening device for applying water to the fibers of the formed fiber mat and with a solidification device for solidifying the formed fiber mat, wherein the fiber mat in the solidification device is arranged between two, each one of the fiber mat facing contact surface having support elements and is pressed and that the solidification device is designed such that the pressing time is less than ls, in particular less than 0.8s, preferably less than 0.5s.

The invention also relates to a fiber mat which is produced by the method according to claim 1.

The invention expressly extends to such embodiments, which are not given by combinations of features of explicit back references of the claims, whereby the disclosed features of the invention - as far as is technically feasible - can be combined with each other.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings.

Show it

Figure 1 shows a first possible embodiment of a device according to the invention in a simplified representation; Figure 2 shows a second possible embodiment of a device according to the invention in a simplified representation;

Figure 3 shows another possible embodiment of a device according to the invention in a simplified representation;

FIG. 4 a shows by way of example a fiber mat with applied water in cross section in FIG

simplified representation;

FIG. 4b shows by way of example a fiber mat with applied water according to FIG. 4a in FIG

Top view in a simplified representation;

Figure 5a shows a first possible variant of a device according to the invention for the

discontinuous production process in a simplified representation;

FIG. 5b shows a second possible variant of a device according to the invention for the discontinuous production process in a simplified representation;

1 shows a first possible embodiment of a device 1 according to the invention for producing a fiber mat 10 in a simplified representation. The provided recycled product, which contains natural fibers, which may be selected for example from the group of pulp, wood pulp, cotton, annual plants such as bamboo, straw, grass, hemp, is fed to a treatment plant 2 via a hopper. The recycled goods are in air-dry condition, ie the dry content has adjusted to an equilibrium value according to the climatic conditions of the environment. However, the recycled fabric may also be lightly wetted, such as having a dry content in the range of greater than 80%. The humidification can basically take place anywhere in the treatment plant 2. There, the recycled material is crushed, freed of impurities and broken down into Einzelfasem and / or fiber bundles 12, for example in Hochkonsistenzrefinem or in Querstromzerfaserem or mills. Subsequently, a cleaning of the fraction of the individual fibers and / or fiber bundles 10 can take place. In this step, further impurities are removed. This processing takes place in the air stream, which the Einzelfasem and / or fiber bundles 10th contributes, allows a uniform spatial distribution and transported. Subsequently, the impurities contained in the air stream are discharged in a run as a cyclone separator 3 via the air flow 3 a. The proportion of the air flow with the individual fibers and / or fiber bundles 10 is fed to a dry forming device 4. It is arranged opposite a speed-continuous, endless permeable or impermeable forming belt 5, which may be designed as a woven screen or as a membrane, and comprises a closed space with turbulence elements for the homogeneous distribution of the individual fibers and / or fiber bundles 10 in the stream. The enclosed space is open to the forming belt 5, so that the individual fibers and / or fiber bundles 10 can be deposited on the forming belt 5 to form a fiber mat 10. The formed fiber mat 10 is deposited so that a very high specific volume of more than 12 cm ³ / g is achieved. In the area of the formation of the fiber mat 10, the forming belt 5 runs obliquely upward in this example at an angle. In the case of an impermeable forming belt 5, not shown here, suction elements for supporting the formation of the fiber mat 10 may be arranged on the side of the forming belt 5 opposite the dry forming device 4. To further assist in the formation and transport of the fiber mat 10, particularly in the case of an impermeable forming belt 10, the forming belt 5 may be electrostatically charged. The deposited fiber mat 10 is guided on the Formierband 5 lying to a horizontally extending portion. In this section is a moistening device 7a for applying water to the individual fibers and / or fiber bundles 10 of the formed fiber mat 10. The water is applied in this example by a spray nozzle on the top of the laid fiber mat 10 in the form of small droplets 13. Since the droplets 13 are supposed to be small, the spray nozzle is designed so that the diameters of the droplets 13 are less than or equal to 3 mm. The amount of water applied should be as small as possible and just sufficient to activate the adhesive bonding potential between the individual fibers and / or fiber bundles. In principle, the water can also be applied in the form of water vapor, the state of which is adjusted in such a way that the vapor condenses on impacting the individual fibers and / or fiber bundles 10. The application amount of water in this example is between 5% and 20% of the mass of the laid fiber mat 10. The humidifying device 7a is followed by a solidifying device 8 at a distance. The distance is chosen so that as little water as possible can penetrate into the interior of the individual fibers and / or fiber bundles and is available for bonding to the surfaces of the individual fibers and / or fiber bundles 12. The Hardening device 8 follows at the latest after 20 seconds after the application of water. The distance therefore depends on the speed of the forming belt encircling in a running direction 22. In the solidifying device 8, the moistened fiber mat 10 is pressed and heated between a support element 9b, in this case the forming belt 5, and a heated support element 9a. The support member 9a is formed by a press roller 15. It is also possible to carry out the support element 9a as a heatable calender roll. The forming belt 5 and the support element 9a each have a contact surface which is in direct contact with the fiber mat 10. The pressing time is less than ls and more than 0,0lms (milliseconds). The pressing time or pressing period in the press nip formed by the press roller 15 and one of these opposed press members 14 can be determined by the configuration of the press roller 15 and the press member 14. Thus, the pressing member 14 and / or the press roller 15 can be equipped with a hard or soft roll cover and so the length of the press nip and thus, for a certain speed with which the fiber mat 10 moves, and the pressing time are set. Another possibility is to carry out the pressing element 14 as a shoe roll or belt press or belt calender with extended press nip. The solidification device 8 is designed and operated such that the dry content of the solidified fiber mat at the end of the solidification device 8 is more than 80%. This reduces or avoids the expense of thermal drying of the fiber mat 10. After the solidification device 8, the fiber mat 10 is led away from the forming belt 5 and forwarded to a padding 21.

A second possible embodiment of a device 1 according to the invention is shown in a simplified representation in FIG. With regard to the description of the elements corresponding to the elements in Figure 1 with the same reference numerals, reference is made to the description in Figure 1. Also in this embodiment, the provided recycled product is fed to a treatment plant 2 via a funnel and processed there to Einzelfasem and / or fiber bundles. Subsequently, the individual fibers and / or fiber bundles are deposited in a dry forming device 4 on the upper side of the horizontally extending part of the forming belt 5. After the dry forming device 4, the fiber mat 10 is precompressed slightly by a compacting device 6 before a moistening device 7a, 7b to 70% of the specific volume of the fiber mat 10 before the compacting device 6. That is, the fiber mat thickness 11 after the compacting device 6 is 70% of Fiber mat thickness 11 in front of the compacting device 6. Subsequently, the individual fibers and / or fiber bundles 12 of the fiber mat 10 are moistened by a moistening device 7a, 7b. In this example, the individual fibers and / or fiber bundles 12 of the fiber mat are moistened twice in succession by a respective moistening device 7a, 7b before it passes through the solidifying device 8. The second moistening device 7b is formed by the support element 9a designed as a pressure roller 15 and a water application nozzle, wherein the pressure roller 15 simultaneously acts as an application element 7d. Both humidifiers 7a, 7b can both be used. However, it is also possible that only one of the two humidifying devices 7a, 7b can be provided. The surface of the press roll 15 directly contacts the fiber mat 10 in a contact area and has a structure or porous layer for receiving and storing water applied to the surface through a water applicator nozzle or, in the case of steam, via a vapor deposition box. The press roll 15 forms with the pressing member 14 the press nip of the solidification device 8. Here, therefore, the water is applied immediately before the solidification device 8 on top of the fiber mat. After the solidification device 8, the fiber mat 10 is again supplied to a filling. The formed fiber mat 10 is deposited so that a very high specific volume of more than 12 cm ³ / g is achieved. The application amount of water in this example is between 5% and 20% of the mass of the laid fiber mat 10. The humidifying device 7a is followed by a solidifying device 8 at a distance. The distance is chosen so that as little water as possible can penetrate into the interior of the individual fibers and / or fiber bundles and is available for bonding to the surfaces of the individual fibers and / or fiber bundles 12. The solidification device 8 follows at the latest after 20 seconds after the application of water. The pressing time in the solidifying device 8 is less than ls and more than 0.0 lms.

In the example of Figure 3, a further embodiment of the device 1 of the invention is shown in a simplified representation, in which the solidification device 8 is not arranged on the forming belt 5, but in the region of a downstream support member 9a, which is designed as a band. The individual fibers and / or fiber bundles 12 are again formed on the forming belt 5 to form a loose fiber mat 10 with a fiber mat thickness 11 and optionally moistened by a moistening device 7a. Subsequently, the fiber mat 10 by a designed as a band support member 9a from Formierband 5 removed. The circulating, endless belt is guided over a first and a second roller, wherein the second roller acts as a pressing element 14 in the solidifying device 8. This forms, together with the support element 9b designed as a press roll, the press nip of the solidification device 8. The support elements 9a, 9b have contact surfaces which are in direct contact with the fiber mat 10. In this example, both contact surfaces are impermeable and designed such that the fiber mat 10 is supported over the entire surface. Before the solidification device 8, a moistening device 7c can optionally be provided to apply water to the underside of the fiber mat 10. Before that, a compression device 6 can again be arranged. The formed fiber mat 10 is deposited so that a very high specific volume of more than 12 cm ³ / g is achieved. The application amount of water in this example is between 5% and 20% of the mass of the laid fiber mat 10. The humidifying device 7a is followed by a solidifying device 8 at a distance. The distance is chosen so that as little water as possible can penetrate into the interior of the individual fibers and / or fiber bundles and is available for bonding to the surfaces of the individual fibers and / or fiber bundles 12. The solidification device 8 follows at the latest after 20 seconds after the application of water. The pressing time in the solidifying device 8 is less than ls and more than 0.0 lms.

FIG. 4a shows, by way of example, a fiber mat 10 with applied water in cross-section in a simplified representation. The water may be applied in a liquid form or as a vapor condensed upon application to the fiber mat 10. The Einzelfasem and / or fiber bundles 12 are formed in the dry forming device 4 in a loose scrim to form a fiber mat 10, that the distance between the Einzelfasem and / or fiber bundles 12 leads to a formation of water droplets 13 initially on the surface of the fiber mat 10. The solidification step then leads to a distribution of the water applied to the surface of the fiber mat 10 over the fiber mat thickness 11.

FIG. 4b shows by way of example a fiber mat 10 with applied water in a top view in a simplified representation.

The devices 1 of FIGS. 1 to 3 are suitable for the continuous production of an endless flat fiber mat 10. FIG. 5a shows a first possible variant of a device 1 according to the invention for the discontinuous production process in a simplified representation. The sheet-like fiber mat 10 is produced piecewise as a sheet-like product 20. Such products 20 can for example be processed in a further processing step for boxes or boxes. After the processing plant 2, the individual fibers and / or fiber bundles 12 are fed to a dry forming device 4 and placed in a forming mold 17 assigned to the dry forming device 4 to form a piece of fiber mat 10. Subsequently, it is moistened by a separate, not shown, separate moistening device and then solidified by pressing in its geometry on the forming mold 17 matched punch 18. Again, the punch 17 may be heated. In the case of the device 1 shown in FIG. 5a, the stamp comprises an application element 7d having a contact surface. This is connected as a porous, compressible layer with the stamp. After each pressing process, the application element is moistened. The punch 18 and the forming die 7 together constitute the solidifying device 8, and the applicator 7d and the forming die 17 act as supporting members 9a, 9b.

FIG. 5b shows a second possible variant of a device 1 according to the invention for the discontinuous production process in a simplified representation. This device shows a section of the device shown in FIG. 5a. In contrast to FIG. 5a, instead of a flat product, a three-dimensional product 20 is produced in one step. In this case, the flat fiber mat 10 is formed and solidified in a spatial forming mold 17 for producing a three-dimensional product 20. The forming mold 17 and the punch 18 are matched to the geometry of the product 20. Three-dimensional products 20 may be boxes, boxes, etc., or parts thereof.

Corresponding elements of the embodiments in the figures are provided with the same reference numerals. The functions of such elements in the individual figures correspond to each other, unless otherwise described and it does not lead to contradictions. A repeated description is therefore omitted. It is also pointed out that the distinguishing features of the exemplary embodiments shown are interchanged and combined with one another can. The invention is therefore not limited to the illustrated combinations of features of the exemplary embodiments shown.

List of Reference Devices

processing plant

cyclone

a air

Trockenformiervorrichtung

forming belt

compacting device

a humidifier

b Humidifier

c Humidifier

d order element

Solidification device

a support element

b support element

0 fiber mat

1 fiber mat thickness

2 Einzelfasem and / or fiber bundles

3 drops of water

4 pressing element

5 press roll

6 deflecting roller

7 Forming form

8 stamps

0 product

1 reel

2 direction

Claims

Method and device for producing a fibrous web in a paper machine Claims

Anspruch [en] A process for producing a fiber mat which is particularly suitable for use in the manufacture of packaging board or fibrous material

Construction elements, from a fibrous recycled material comprising corrugated cardboard waste and / or waste cardboard and / or waste paper and / or paper or cardboard waste from papermaking, comprising the following steps: a. Collecting and providing the fibrous recycled goods; b. Low-water treatment of fiber-containing recycled goods in the airstream to produce commodities comprising individual fibers and / or fiber bundles; c. Forming the Einzelfasem and / or fiber bundles (12) in Fuftstrom to a flat fiber mat (10) by a dry forming process; d. Applying water to the fibers of the formed fiber mat (10); e. Solidifying the formed fiber mat (10);

wherein the fiber mat (10) in the solidification step e) between two, in each case one of the fiber mat (10) facing contact surface,

Supporting elements (9a, 9b) lying with a pressing time of less than ls,

especially less than 0.8s, preferably less than 0.5s is pressed.

2. The method according to claim 1,

characterized in that

the fiber mat (10) is pressed with a pressing time of more than 0.0lms, in particular of more than 0, lms, preferably of more than lms.

3. The method according to any one of the preceding claims,

characterized in that

the solidification step e) follows the application step d) after a maximum of 20 seconds, in particular after a maximum of 10 seconds, preferably after a maximum of 5 seconds.

4. The method according to any one of the preceding claims,

characterized in that

the solidification step e) is carried out so that the fiber mat (10) thereafter has a solids content of more than 50%, in particular more than 70%, preferably more than 80%, particularly preferably more than 90%.

5. Method according to one of the preceding claims,

characterized in that

the treatment step b) is carried out with fibers having a solids content of more than 50%, in particular more than 70% and preferably more than 80%.

6. The method according to any one of the preceding claims,

characterized in that

in the forming step c) a flat fiber mat (10) having a specific volume of more than 12 cm ³ / g, in particular more than 20cm ³ / g, preferably more than 25cm ³ / g is placed.

7. The method according to any one of the preceding claims,

characterized in that.

after the forming step c) the flat fiber mat (10) is precompressed, in particular to a value of more than 50%, preferably of more than 70% of the specific volume of the fiber mat (10) laid in the forming step e).

8. The method according to any one of the preceding claims,

characterized in that

in the application step d) the laid fiber mat (10) with an amount of water in the range between 5% and 50%, in particular between 5% and 40%, preferably between 5% and 30% of the mass of the laid fiber mat (10) is acted upon.

9. The method according to any one of the preceding claims,

characterized in that

at least one support element in the solidification step e) is formed in such a way that the fiber mat (10) is supported over its entire area or zone-wise.

10. The method according to any one of the preceding claims,

characterized in that

at least one support element (9a, 9b) in the solidification step e) is made permeable or impermeable.

11. The method according to any one of the preceding claims,

characterized in that

the contact surface of at least one support element (9a, 9b) smooth for smoothing or with a structure for structuring the fiber mat (10) is executed.

12. The method according to any one of the preceding claims,

characterized in that

the flat fiber mat (10) is produced endlessly.

13. The method according to any one of the preceding claims 1 to 11,

characterized in that

the flat fiber mat (10) is produced piecewise.

14. An apparatus for carrying out the method according to claim 1 for producing a fiber mat (10), which is particularly suitable for use in the production of packaging board or fibrous construction elements, from a fibrous recycled goods, comprising corrugated cardboard waste and / or waste cardboard and / or waste paper and / or paper or cardboard waste from papermaking, with a water treatment plant (2)

Preparation of the fiber-containing recycled goods in the airstream to raw material which individual fibers and / or fiber bundles (12) comprises; and with one

Dry forming device (4) for forming the Einzelfasem and / or

Fiber bundle (12) in the air flow to a flat fiber mat (10), and with a humidifying device (7a, 7b, 7c) for applying water to the

Single fiber and / or fiber bundle (12) of the formed fiber mat (10) and with a solidification device (8) for solidifying the formed

Fiber mat (10),

wherein the fiber mat (10) in the solidification device (8) between two, each one of the fiber mat (10) facing contact surface, having support elements (9a, 9b) is arranged and pressed and that the

Solidification device (8) is designed such that the pressing time is less than ls, in particular less than 0.8s, preferably less than 0.5s.

15. fiber mat (10) by production according to the method of claim 1.