Method for manufacturing a fibrous web

Abstract

The invention relates to a method for producing a fibrous web (1), in particular a paper towel web or a nonwoven, which is produced by means of a dry-laid process and which is pressed and consolidated in an extrusion nip between a first support element (2) and a second support element (3) in an extrusion step, the first and second support elements (2, 3) each having a contact surface (2.1, 3.1) facing the fibrous web (1). The contact surface (2.1) of at least one first support element (2) is designed to produce at least one low-pressure region (4) and at least one high-pressure region (5) in the fibrous web (1) and to exert an extrusion pressure of more than 10 MPa, in particular more than 15 MPa, preferably more than 25 MPa, on the fibrous web (1) in the at least one high-pressure region (5).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing fiber webs, particularly tissue webs or nonwoven fabrics, wherein the fiber webs are formed by a dry web forming process.

[0002] The present invention also relates to a machine for carrying out the method and a fiber web with better strength. Background Technology

[0003] Reinforcing agents are typically used when manufacturing fiber webs using wet web forming processes, especially when manufacturing tissue webs or nonwoven fabrics.

[0004] Wet web forming is the most common method for manufacturing fiber webs, such as tissue paper webs and nonwoven fabrics. At the start of the manufacturing process, the solids of the fiber web are suspended in water and fed through a headbox into the forming section of the paper machine. Mechanical dewatering occurs in the downstream press section, followed by thermal drying in the drying section. The presence of water forms hydrogen bonds, which increase the basic strength of the fiber web. Reinforcing agents are added to the fiber web to further improve its basic strength.

[0005] To optimize the fiber web manufacturing process and reduce energy consumption and carbon dioxide emissions, dry web forming processes are increasingly being adopted. Compared to wet web forming, dry web forming eliminates the need for water in fiber web preparation, thus saving significant energy and carbon dioxide emissions by avoiding the heat drying step. However, in these methods, because little or no water is used, the strength of the fiber web cannot be fully achieved through hydrogen bonding; therefore, the fibers are almost entirely formed into the web through dry web forming. In the manufacture of tissue paper webs and nonwoven fabrics, latex polymers are sprayed onto the paper surface, or synthetic molten fibers are added to the fibers before dry web forming. The fiber web with the molten fibers is then heated. The molten fibers melt and bond with the cellulose fibers of the fiber web, thereby increasing or forming the strength of the fiber web. These reinforcing agents are also expensive, accounting for a large proportion of the production cost of these papers. Furthermore, latex polymers and molten fibers have poor or no biodegradability. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to provide a method and machine for achieving inexpensive and eco-friendly enhancement in the manufacture of fiber webs, such as tissue webs and nonwoven fabrics, and to reduce or even completely eliminate the disadvantages of known methods.

[0007] The aforementioned technical problem is solved by the method according to the present invention. A method is proposed for manufacturing fiber webs, particularly tissue webs or nonwoven fabrics, the fiber webs being formed by a dry web-forming process, and the fiber webs being extruded and cured in an extrusion gap located between a first support element and a second support element in an extrusion step, the first and second support elements each having a contact surface facing the fiber webs, wherein the contact surface of at least one first support element is designed to construct at least one low-pressure zone and at least one high-pressure zone in the fiber webs, and an extrusion pressure greater than 10 MPa, particularly greater than 15 MPa, preferably greater than 25 MPa, is applied to the fiber webs in the at least one high-pressure zone.

[0008] A three-dimensional structure is imprinted in the fiber web through the contact surface of the first support element in the extrusion gap. This invention improves strength, such as tensile strength, without compromising desired properties of the fiber web, such as thickness, absorbency, softness, and specific volume.

[0009] By intense localized compression of the fiber web in at least one high-pressure zone, where the fiber web is compressed, at least one low-pressure zone is determined. The sum of the areas of all low-pressure zones and at least one high-pressure zone on the test surface of the fiber web corresponds to the total area and thus to the test area. Therefore, the area share of at least one high-pressure zone is simply derived.

[0010] It is also advantageous that multiple extrusion slits or multiple extrusion steps, preferably two extrusion slits, and especially three extrusion slits, are arranged sequentially. This allows for advantageous further improvement of parameters with only a slight increase in investment costs. Here, additional components, such as coating devices for moisture-resistant agents or other reinforcing agents to further increase strength, can be added between, before, or after each extrusion slit. The alternative embodiments of the extrusion slits shown in the accompanying drawings can also be combined with each other in different ways; for example, it is conceivable that in the first extrusion slit... Figure 2 Or the embodiment shown in 3, and in the second and third extrusion gaps is Figure 5 The implementation method shown.

[0011] New improvements to the manufacturing process for fiber webs, aimed at reducing energy consumption and CO2 emissions, involve a dry web-forming process. In this method, fibers are separated and conveyed to a dry web-forming apparatus for forming the fiber webs, in a nearly dry, maximally air-dried state. The required strength of the fiber webs thus produced cannot be sufficiently achieved by forming hydrogen bonds because little or no water is used, and therefore the fibers used to form the webs are in a nearly dry state.

[0012] Here, the present invention is particularly advantageous and plays a role in the manufacture of tissue paper webs and nonwoven fabrics. With this type of paper, sufficient strength must be achieved on one side during the dry web forming process, and on the other side, requirements must be met in terms of application aspects, such as specific volume, absorbency, water content, stretchability, and hand feel. Thus, it is suitable in the present invention to apply a compressive pressure greater than 10 MPa, especially greater than 15 MPa, to the fiber web in a high-pressure zone, so as to achieve the requirements for fiber web application in addition to strength.

[0013] In the case of toilet paper, the invention can be applied particularly advantageously for the aforementioned reasons. Toilet paper can include paper towels and nonwoven fabrics. They can include products from the following exemplary and incomplete group: wet wipes, towels, paper napkins, tablecloths, etc.

[0014] This invention can also have advantageous effects in the manufacture of nonwoven fabrics, as they can include plastic fibers that at least partially do not form hydrogen bonds.

[0015] It is also advantageous that the tissue paper or nonwoven fabric to be manufactured is designed with a unit area weight of 10g / m² to 50g / m², preferably 12g / m² to 45g / m².

[0016] Therefore, it is also advantageous that the at least one high-voltage zone is designed with a diameter of less than 9mm. 2 Especially smaller than 4mm 2 And preferably less than 0.5mm 2 The area. Thus, sufficient strength is generated on one side, and the requirements for application, such as specific volume, water absorption, water content, spreadability, and so-called "feel," are met on the other side.

[0017] In a favorable design scheme, it is also feasible to design at least one high-voltage zone with a 0.5mm... 2 Up to 2mm 2 The area within the specified range.

[0018] It is also advantageous that the at least one high-pressure zone accounts for 5% to 60% of the area of ​​the compressed area, particularly 5% to 20%, particularly 5% to 30%, preferably 30% to 60%, and especially preferably 35% to 50%.

[0019] Multiple high-pressure zones can be constructed in possible design schemes. In this case, the total area of ​​these high-pressure zones accounts for 5% to 60% of the area of ​​the extruded area, particularly 5% to 30%, preferably 30% to 60%, and especially preferably 35% to 50%.

[0020] In practice, multiple high-pressure zones can be constructed, and the spacing between adjacent high-pressure zones is less than the average fiber length of the fiber width.

[0021] Alternatively, it is conceivable that the at least one high-pressure zone is connected to an adjacent high-pressure zone via another high-pressure zone. The other high-pressure zones can extend linearly. These other high-pressure zones extend in a star shape from one high-pressure zone. This improves the strength of the fiber web while also providing a better specific volume.

[0022] In cases where multiple high-pressure zones are provided, an extrusion pressure of greater than 10 MPa, particularly greater than 15 MPa, and preferably greater than 25 MPa is applied to the fiber web in each high-pressure zone.

[0023] For particularly high strength, or in the case of paper towels or nonwoven fabrics containing specific fiber types, the extrusion pressure in the high-pressure zone can be up to 70 MPa, preferably up to 50 MPa.

[0024] In the at least one low-pressure zone, an extrusion pressure of less than 10 MPa, particularly less than 8 MPa, preferably greater than 0 MPa, or in the range of 0 to 3 MPa, may be applied to the fiber web. The at least one low-pressure zone is preferably only lightly extruded, such that the extrusion pressure is approximately greater than 0 MPa, particularly greater than 0.1 MPa, preferably greater than 1 MPa.

[0025] Advantageously, the flattened fiber web is also pre-compressed or extruded in the low-pressure zone, particularly to a volume less than 50%, preferably less than 80%, of the original specific volume of the fiber web in the dry web forming process. In other words, the compression or extrusion is designed such that the thickness of the fiber web laid immediately following at least one extrusion step is at most 50%, preferably at most 80%, of the thickness of the fiber web laid in the dry web forming process before the extrusion step. This improves the stability of the laid fiber web. This is particularly suitable for the continuous production of fiber webs. Consequently, the fiber web becomes less sensitive to airflow.

[0026] The characteristics of dry-laid fiber webs typically lie in their specific volumetric strength, which is greater than 12 cm³ / g, particularly greater than 20 cm³ / g, and preferably greater than 25 cm³ / g. This is beneficial for both the uniform distribution of individual fibers and / or fiber bundles within the fiber web's volume and for the effectiveness and uniformity of water distribution. Therefore, a fiber web with uniform strength distribution can be obtained using minimal water. In other words, the thickness of the fiber web before the extrusion step is greater than 2 mm, particularly greater than 5 mm, and preferably greater than 10 mm.

[0027] In an advantageous embodiment, the dry web forming process is carried out prior to at least one extrusion step, such that the dry content of the fiber web exceeds 50%, particularly 70%, preferably 80%, and especially preferably 90% before the at least one extrusion step. Typically, the dry web forming fiber web has a very high dry content because no or only a small amount of water needs to be added during slurry preparation.

[0028] In an alternative implementation, the dry content can be affected if a wet strength agent or other reinforcing agent, such as water, is added prior to the extrusion step, for example by heating the fiber web during the extrusion step.

[0029] The first support element and / or the second support element may be designed as rollers with contact surfaces, which may or may not have protrusions for generating at least one high-pressure zone. The rollers may optionally be designed as rollers with a metal or coated surface, or as shoe rollers or rollers with plastic sleeves.

[0030] In rollers that preferably have a metallic or coated surface, the roller surface directly forms the contact surface. Here, rollers with a preferred metallic or coated surface are harder than rollers with plastic sleeves. In the case of shoe rollers, the pressure sleeve forms the contact surface. In the case of rollers with plastic sleeves, the sleeve forms the contact surface.

[0031] The contact surface can be designed with protrusions.

[0032] For example, the first support element is designed as a roller with a surface that directly forms a contact surface, and the second support element is designed as a roller with a plastic sleeve and a soft surface; such a combination of the first and second support elements can be envisioned. This forms a so-called "soft clamp" compression gap.

[0033] For example, the contact surface of the first support element is preferably a raised metal surface or a coated surface of the roller.

[0034] As an alternative, a plastic roller sleeve with raised protrusions can be provided. Here, the roller sleeve with raised protrusions forms the contact surface of the support element.

[0035] In the case where a contact surface is formed directly on the roller surface, the surface can be designed to be raised, for example, by using processing techniques such as etching or milling.

[0036] In another alternative embodiment, the second support element is preferably designed as a roller with a metal or coated surface and a smooth surface without protrusions.

[0037] In another conceivable combination, the first support element is designed to have a preferred metal or coated surface and a raised roller, and the second support element is designed to have a preferred metal or coated surface and a smooth surface. A pressure roller with its contact surface directly contacting the roller surface serves as the first support element, and a corresponding roller with its contact surface directly contacting the roller surface serves as the second support element; their combination relates to a "hard clamp" compression gap.

[0038] In an alternative embodiment, the first support element and / or the second support element are designed as rollers, and the first support element and / or the second support element are preferably designed with protrusions for fiber web structuring (or texturing).

[0039] The first support element and / or the second support element may be designed as a looping strip with raised sections, which are used to generate multiple high-voltage zones.

[0040] The recirculating belt can be designed as a film or woven belt, such as a screen, with protrusions on the contact surface. These protrusions may include and be embossed with plastic.

[0041] The looped belt can be designed as a braided belt, where the protrusions can be formed by the braided threads.

[0042] The first support element and / or the second support element may be permeable or impermeable.

[0043] Rollers used to form the extrusion gap can be arranged in first support elements and / or second support elements made of belts, each forming a loop. The extrusion gap can be formed by pressure rollers and corresponding rollers. Pressure rollers can also be designed as shoe rollers with extended extrusion gaps. The extrusion gap can also be formed by calendering rollers.

[0044] In a possible implementation, at least one high-voltage zone may be formed by a protrusion on the contact surface of at least the first support element. The cross-sectional shape of the protrusion may be circular, triangular, rectangular, or elongated, such that the shape of the high-voltage zone may also be correspondingly circular, triangular, rectangular, or elongated. The shape of the high-voltage zone may also be different.

[0045] The height of the protrusion is preferably 0.05 mm to 1 mm, particularly 0.05 mm to 0.5 mm. Thus, the pressure in at least one high-pressure zone and at least one low-pressure zone can be adjusted relative to each other.

[0046] In a possible improvement, at least the first support element is designed as a perforated thin plate, and the at least one high-pressure zone is generated through the contact surface of the thin plate, while the low-pressure zone is generated through the perforated surface of at least the first support element. Therefore, the difference in this embodiment is that each opening forms a low-pressure zone, while only a high-pressure zone is formed in the middle.

[0047] To increase strength, at least one high-pressure zone can be heated to a temperature of 50ºC to 250ºC, especially 110ºC to 160ºC, particularly the surface temperature of the roller, by means of a support element.

[0048] In a possible improvement, at least the contact surface of the first support element is designed to generate multiple high-voltage zones and these high-voltage zones are arranged in a pattern for aesthetic purposes.

[0049] In another feasible design, at least the contact surface of the first support element can be designed to generate multiple high-pressure zones, and the arrangement of these high-pressure zones can be chosen such that the tensile strength in the plane of the fiber web is direction-dependent. Thus, for example, by providing more high-pressure zones per unit length in one direction than in another, the tensile strength in that direction can be increased. Consequently, the density of high-pressure zones in a particular direction is higher.

[0050] It is also conceivable that paper properties, such as strength and orientation, can be designed by adjusting the density and / or shape of the high-pressure zone.

[0051] In a feasible design, the second support element, opposite to at least the first support element, is flexibly designed to structure the side of the fiber web that contacts the second support element. Consequently, the back side of the fiber web is also structured, thereby supporting and better meeting application requirements such as specific volume, absorbency, water content, spreadability, and so-called hand feel.

[0052] In some cases, it is advantageous to add wet strength agents or other reinforcing agents to the fiber web before and / or after the extrusion step, which can further improve the strength.

[0053] The fiber web can also be wrinkled after the extrusion step.

[0054] Another advantage of dry-laid fiber webs is that if the fiber webs are subjected to a large area of ​​slight pre-compression before entering the extrusion gaps, the laid, loose fiber mat can resist airflow.

[0055] The technical problem described above is also solved according to the invention by a machine for implementing the method according to the invention, the method being used to manufacture fiber webs, particularly tissue webs or nonwoven fabrics. The machine includes a dry web forming section and an extrusion slit, in which the fiber web is extruded and cured in the extrusion slit located between a first support element and a second support element, the first and second support elements each having a contact surface facing the fiber web, wherein the contact surface of at least one first support element is designed to construct at least one low-pressure zone and at least one high-pressure zone in the fiber web, and an extrusion pressure greater than 10 MPa, particularly greater than 15 MPa, preferably greater than 25 MPa, is applied to the fiber web within the at least one high-pressure zone.

[0056] The present invention also relates to a fiber web formed by a dry web-forming process according to the method of the present invention, the fiber web having at least one low-pressure zone and at least one high-pressure zone, wherein an extrusion pressure of greater than 10 MPa, particularly greater than 15 MPa, preferably greater than 25 MPa is applied to the fiber web in the at least one high-pressure zone.

[0057] The invention also extends to embodiments where no specific combination of features is given, and the features disclosed herein may be combined with each other as needed, provided that it is technically advantageous. Attached Figure Description

[0058] Further features and advantages of the invention will become apparent from the following description of preferred embodiments in conjunction with the accompanying drawings.

[0059] In the attached diagram:

[0060] Figure 1 A simplified schematic diagram illustrating a possible embodiment of the fiber web according to the invention;

[0061] Figure 2 A simplified, non-scale view showing a possible embodiment of the extrusion slot of the extrusion assembly of the machine according to the invention; wherein the two support elements are implemented as belts or rollers with sleeves;

[0062] Figure 3 A simplified, non-scale view showing a possible embodiment of the extrusion slot of the extrusion assembly of the machine according to the invention; wherein the two support elements are implemented as rollers and are smooth, the surfaces of the rollers being directly configured as contact surfaces;

[0063] Figure 4 A simplified, non-scale view showing a possible embodiment of the extrusion slot of the extrusion assembly of the machine according to the invention; wherein two support elements are implemented as rollers and have protrusions, the surfaces of the rollers being directly configured as contact surfaces;

[0064] Figure 5 A simplified, non-scale view of a possible embodiment of the extrusion gap of the extrusion assembly of the machine according to the invention is shown; wherein two support elements are implemented as rollers, the surfaces of which are directly configured as contact surfaces. Detailed Implementation

[0065] exist Figure 1 The diagram shows a simplified top view of a possible embodiment of the fiber web according to the invention. In this embodiment, the fiber web 1 has multiple high-pressure zones 5. These high-pressure zones 5 are subjected to vigorous compression during manufacturing to produce higher strength. The local compression pressure in the high-pressure zones 5 is greater than 10 MPa. The area between these high-pressure zones 5 is only lightly compressed and forms a single low-pressure zone 4. The compression pressure in the low-pressure zone 4 is in the range of greater than 0 MPa to 1 MPa. The high-pressure zones 5 are designed in a trapezoidal shape. However, the high-pressure zones can also have any shape, such as circular, triangular, quadrilateral, etc. The high-pressure zones 5 are evenly distributed in the compressed surface 7. However, these high-pressure zones can also be designed with a pattern to make the fiber web 1 more attractive. This is advantageous in tissue paper webs and nonwoven fabrics. The spacing 6 between adjacent high-pressure zones 5 is preferably less than the average fiber length of the fiber web 1. The dimensions of each high-pressure zone 5 are less than 9 mm. 2 Furthermore, it has a surface area ratio of 5% to 50% on the extrusion surface. The dimensions of each high-pressure zone 5 can be the same or different.

[0066] Figure 2 A simplified, non-scale view of a possible embodiment of the extrusion slit 9 of the extrusion assembly of the machine according to the invention is shown. A fiber web 1 is guided along a running direction 12 through the extrusion slit 9 located between a first support element 2 and a second support 3. The first support element 2 and the second support element 3 are formed by a circulating belt. The extrusion slit 9 includes a pressure roller 10 arranged within an annulus of the first support element and a corresponding roller 11 arranged within an annulus of the second support element. The first support element 2 has protrusions 8 in its contact surface facing the fiber web 1 for generating a high-pressure zone 5. The fiber web 1 is locally and intensely compressed by the protrusions 8 as it passes through the extrusion slit 9 and is thereby solidified. After the extrusion slit 9, these protrusions 8 are released from the fiber web 1, thereby creating a structured three-dimensional surface structure with a high-pressure zone 5 and, in this embodiment, a single low-pressure zone 4.

[0067] Figure 3 A simplified, non-scale view of an alternative possible embodiment of the extrusion slit 9 of the extrusion assembly of the machine according to the invention is shown. A fiber web 1 is guided through the extrusion slit 9 along the running direction 12 between a first support element 2 and a second support element 3. The extrusion slit 9 includes a pressure roller 10 and a corresponding roller 11.

[0068] The pressure roller 10 can be arranged within the ring of the first support element 2, wherein the first support element 2 is formed by a circulating belt or the roller sleeve of the pressure roller 10.

[0069] The corresponding roller 11 preferably forms the second support element 3 and the second contact surface 3.1 through a smooth surface that is metallic or coated. The first support element 2 has protrusions 8 in the contact surface facing the fiber web 1 for generating a high-pressure zone 5. The fiber web 1 is locally and intensely compressed by the protrusions 8 as it passes through the extrusion gap 9 and is thereby solidified. After the extrusion gap 9, these protrusions 8 are released from the fiber web 1, thereby creating a structured three-dimensional surface structure with a high-pressure zone 5 and, in this embodiment, a single low-pressure zone 4.

[0070] Figure 4 A simplified, non-scale view of an alternative possible embodiment of the extrusion slit 9 of the extrusion assembly of the machine according to the invention is shown. A fiber web 1 is guided through the extrusion slit 9 along the running direction 12 between a first support element 2 and a second support element 3. The extrusion slit 9 includes a pressure roller 10 and a corresponding roller 11.

[0071] The corresponding roller 11 can be arranged within the ring of the second support element 3, wherein the second support element 3 is formed by a circulating belt or a roller sleeve of the corresponding roller 11.

[0072] The pressure roller 10 preferably forms the first support element 2 and the first contact surface 2.1 by means of a metallic or coated surface with raised features. The first support element 2 or pressure roller 10 has protrusions 8 in the contact surface 2.1 facing the fiber web 1 for generating a high-pressure zone 5. The fiber web 1 is locally and intensely compressed by the protrusions 8 as it passes through the extrusion gap 9 and is thereby solidified. After the extrusion gap 9, these protrusions 8 are released from the fiber web 1, thereby creating a structured three-dimensional surface structure with a high-pressure zone 5 and, in this embodiment, a single low-pressure zone 4.

[0073] Figure 5 A simplified, non-scale view of an alternative possible embodiment of the extrusion slit 9 of the extrusion assembly of the machine according to the invention is shown. A fiber web 1 is guided through the extrusion slit 9 along the running direction 12 between a first support element 2 and a second support element 3. The extrusion slit 9 includes a pressure roller 10 and a corresponding roller 11.

[0074] The corresponding roller 11 preferably forms the second support element 3 and the second contact surface 3.1 through a smooth surface that is metallic or coated.

[0075] The pressure roller 10 preferably forms the first support element 2 and the first contact surface 2.1 by means of a metallic or coated surface with raised features. The first support element 2 or pressure roller 10 has protrusions 8 in the contact surface 2.1 facing the fiber web 1 for generating a high-pressure zone 5. The fiber web 1 is locally and intensely compressed by the protrusions 8 as it passes through the extrusion gap 9 and is thereby solidified. After the extrusion gap 9, these protrusions 8 are released from the fiber web 1, thereby creating a structured three-dimensional surface structure with a high-pressure zone 5 and, in this embodiment, a single low-pressure zone 4.

[0076] Corresponding elements in the embodiments shown in the accompanying drawings are given the same reference numerals. Unless otherwise stated and without contradiction, the functions of such elements in the various drawings correspond to each other. Therefore, repeated descriptions are omitted.

[0077] List of reference numerals

[0078] 1. Fiber fabric width, tissue paper width, non-woven fabric width

[0079] 2 First support element

[0080] 2.1 Contact Surface

[0081] 3 Second support element

[0082] 3.1 Contact Surface

[0083] 4 Low-pressure area

[0084] 5 High-voltage zone

[0085] 6 High-voltage zone spacing

[0086] 7 Extrusion surface

[0087] 8 protrusions

[0088] 9 Extrusion gaps

[0089] 10 pressure rollers

[0090] 11 Corresponding Rollers

[0091] 12 directions of operation

Claims

1. A method for manufacturing a fiber web (1), the fiber web being formed by a dry web forming process, and the fiber web (1) being extruded and cured in an extrusion gap located between a first support element (2) and a second support element (3) in an extrusion step, the first support element (2) and the second support element (3) respectively having contact surfaces (2.1, 3.1) facing the fiber web (1), wherein, The contact surface (2.1) of at least one first support element (2) is designed to form at least one low-pressure zone (4) and at least one high-pressure zone (5) in the fiber web (1), and to apply an extrusion pressure greater than 10 MPa and up to 70 MPa on the fiber web (1) in the at least one high-pressure zone (5).

2. The method according to claim 1, characterized in that, The at least one high-voltage zone (5) is designed with a diameter of less than 9 mm. 2 The area.

3. The method according to claim 1, characterized in that, The structure has multiple high-pressure zones (5), and the spacing between adjacent high-pressure zones (5) is less than the average fiber length of the fiber width (1).

4. The method according to claim 1, characterized in that, The at least one high-voltage zone (5) is connected to an adjacent high-voltage zone (5) through another high-voltage zone (5).

5. The method according to claim 1, characterized in that, The area share of the at least one high-pressure zone (5) in the compressed area (7) is 5% to 60%.

6. The method according to claim 1, characterized in that, An extrusion pressure of less than 10 MPa and greater than 0 MPa is applied to the fiber web (1) in at least one low-pressure zone (4).

7. The method according to any one of claims 1 to 6, characterized in that, Multiple high-pressure zones (5) are generated by multiple protrusions (8) within the contact surface (2.1) of at least the first support element (2).

8. The method according to claim 7, characterized in that, The protrusion (8) is designed to have a height of 0.05 mm to 1 mm.

9. The method according to any one of claims 1 to 6, characterized in that, At least the first support element (2) is designed as a perforated thin plate, and the at least one high-pressure zone (5) is generated through the contact surface (2.1) of the thin plate, and the low-pressure zone (4) is generated through the perforated surface of at least the first support element (2).

10. The method according to claim 1, characterized in that, At least the contact surface (2.1) of the first support element (2) is designed to generate multiple high-voltage zones (5) and these high-voltage zones (5) are arranged in a pattern for aesthetic purposes.

11. The method according to claim 1, characterized in that, The second support element (3) disposed opposite to at least the first support element (2) is flexibly designed to structure the side of the fiber web (1) that contacts the second support element (3).

12. The method according to claim 1, characterized in that, The first support element (2) and / or the second support element (3) are designed as rollers.

13. The method according to claim 7, characterized in that, The first support element (2) and / or the second support element (3) are designed to structure the fiber web (1) by means of a plurality of protrusions (8).

14. The method according to claim 1, characterized in that, The fiber web (1) is added with a wet strength agent or other liquid reinforcing agent before the extrusion step.

15. A machine for carrying out the method according to claim 1, the method for manufacturing a fiber web (1), the machine comprising a dry web forming section and an extrusion slit (9), wherein the fiber web (1) is extruded and cured in the extrusion slit located between a first support element (2) and a second support element (3), the first support element (2) and the second support element (3) respectively having contact surfaces (2.1, 3.1) facing the fiber web (1), wherein, The contact surface (2.1) of at least one first support element (2) is designed to form at least one low-pressure zone (4) and at least one high-pressure zone (5) in the fiber web (1), and to apply an extrusion pressure greater than 10 MPa and up to 70 MPa on the fiber web (1) in the at least one high-pressure zone (5).

16. A fiber web (1) formed by a dry web-forming process according to the method of claim 1, the fiber web (1) having at least one low-pressure zone (4) and at least one high-pressure zone (5), wherein, An extrusion pressure greater than 10 MPa is applied to the fiber web (1) within the at least one high-pressure zone (5).

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