Tool for processing fibrous material, molding system and method for producing fibrous products

Abstract

A tool for processing fibrous material for the production of three-dimensional products, a molding system for producing fibrous products and a method for producing fibrous products are described.

Description

Technical area

[0001] A tool for processing fibrous material for the production of three-dimensional products, a molding system for producing fibrous products and a method for producing fibrous products are described.

[0002] Fibrous materials are sometimes used to produce packaging for food (e.g., trays, capsules, boxes, etc.) and consumer goods (e.g., electronic devices, etc.), as well as beverage containers. Everyday items, such as disposable cutlery and tableware, are also made from fibrous materials. Fibrous materials include natural or synthetic fibers. Recently, there has been an increasing use of fibrous materials that contain natural fibers or are made from fibers that can be obtained, for example, from renewable resources or recycled paper. background

[0003] Fiber-containing materials can be processed in a moist state in a so-called "wet fiber" processing process, where natural fibers, for example, are mixed in an aqueous fiber suspension (pulp) and, if necessary, other additives, such as starch. The pulp can, for example, contain between 0.5 and 10 wt.% natural fibers. The proportion of natural fibers varies depending on the process used to manufacture packaging, etc., and the product properties of the product being manufactured. Additives in a pulp can affect the color, barrier properties, and mechanical properties.

[0004] To produce three-dimensional products from the pulp, the fibers are drawn in via a suction tool. The fibers then adhere to the surface (suction surface) of a suction body, which essentially corresponds to the geometry of the product to be manufactured. The suction also causes the dewatering of the drawn-in fiber cake or the resulting preform. Such a moist preform typically has a moisture content of 50 to 70 wt.% after suction.

[0005] A device and a manufacturing method for producing products from fibers are known, for example, from DE 10 2019 127 562 A1.

[0006] After the fibers have been sucked in, it has already been proposed to pre-press the fiber cake to further dewater and strengthen it. For this purpose, it is also known to spray the underside of the suction tool with water using a spray bar to remove or align fibers in the edge area of ​​the suction body. This ensures that the fiber cakes have a smooth edge without fraying, etc., even before pre-pressing. This ultimately improves the edge formation of fiber-containing products in the subsequent manufacturing process.

[0007] When fibers are sucked in, two types of unwanted fiber deposits can occur in particular. These deposits persist throughout the further processing and lead to protruding fibers in the edge area of ​​the finished product. The fibers that adhere to the suction surface during suction into the cavity of a suction body of the suction tool and form a composite there, show a tendency to settle on a wiper edge in the edge area along the direction of movement (Type I). To remove the protruding fibers on an inner edge of the cavity, pre-press bodies of a pre-press tool can have a lip that pushes protruding fibers along the wiper edge towards the cavity. If fibers protrude beyond the area where the lip grips into the edge area, the lip clamps them off. This results in fiber protrusions.These usually persist throughout the process and ultimately lead to excess fiber at the outer edge of the finished product. This excess appears there as frayed and wave-like edges.

[0008] During the suction process, the suction tool plunges into a pulp basin at the bottom. Upon exiting this basin, another form of unwanted fiber deposits (Type II) occurs, in which fiber clumps from the pulp settle on the tool surface. If clumps settle in the edge area of ​​the cavities, they are usually also clamped off by the lip of a pre-press body. The resulting overhangs remain throughout the process and form large overhangs in the final product.

[0009] However, conventional spray bar designs do not guarantee reliable cleaning of the product edge area, as a spray bar only moves along a linear axis from the upper cavity end to the lower one. This linear axis results in different relative speeds at the differently aligned scraper edges. An edge aligned perpendicular to the spray bar movement is generally cleaned less reliably than an edge aligned horizontally to the spray axis movement.

[0010] Furthermore, it is not possible to specifically clean the edge area of ​​cavities with a spray bar. Instead, a carrier plate for the cavities and all of the cavities installed on it are sprayed in their entirety. Depending on the size and number of cavities installed, only a comparatively small portion of the jet falls on the critical edge area. This also means that the interior of the cavities, which are already filled with fibers at this point, are sprayed with the jet. This softens the fibers again. Furthermore, fiber clumps can break away and partially settle in the edge area that was originally intended to be freed of fibers. Furthermore, such fiber flight not only contaminates the edge area but also contaminates the engine room.

[0011] As a result, it is still necessary to rework the edges of such products. Furthermore, it requires high resource consumption (water, energy, etc.) and complex machine design. Finally, it results in significant contamination of machines and machine components. Task

[0012] In contrast, the task is to provide a solution that eliminates the disadvantages of the state of the art. Another task is to optimize edge formation as early as possible in the fiber processing process. Furthermore, the effort and installation space required for edge formation should be kept to a minimum, while also minimizing resource consumption. Solution

[0013] The above-mentioned object is achieved by a tool for processing fibrous material for the production of three-dimensional products, comprising a shaped body with a three-dimensional surface which essentially depicts the shape of a product to be shaped, wherein the shaped body has a circumferential edge region, further comprising a spray arrangement via which a medium for aligning fibers in the edge region of the shaped body and / or for aligning fibers in the edge region of an opposite tool with a further shaped body can be dispensed.

[0014] Integrating a spray system into the fiber processing tool (suction tool or pre-compression tool) offers the advantage of applying a medium as a targeted stream and directing it to an area critical for edge formation. This way, irrelevant areas are not sprayed, and the spraying targets only the relevant areas with the desired orientation and intensity for the respective application.

[0015] The medium can be, for example, water, a gas or gas mixture (e.g., air), or an air-water mixture. In further embodiments, other media (liquids) or additives for the media described above can also be used, for example, to influence the bonding of fibers and / or (barrier) properties.

[0016] The media stream exiting the spray assembly, which may have multiple outlets, can be directed, for example, toward another opposing tool, so that the fibers on the opposing tool can be pressed into a cavity in the edge area. Alternatively or additionally, fibers that protrude beyond an edge area on the opposing tool can be sprayed away. This results in a clear edge formation without protruding fibers. During further processing, the edge only becomes drier and firmer, so that this does not impair the edge formation. Thus, the final products have an edge formation without fraying.

[0017] The spray arrangement can be designed in such a way that a media stream emerging via, for example, several outlets specifically hits areas of, for example, an opposite tool and fibers and thereby deflects and / or moves them.

[0018] The outlets themselves can be designed as nozzles, for example. Instead of nozzles, simple holes, slots, etc., can also serve as outlets that allow for "spraying."

[0019] In further embodiments, the mold body and the further mold body of an opposing tool can be designed differently. For example, a corresponding pair of tools can be a suction tool and a pre-press tool. Instead of completely spraying the underside of a suction tool using a spray bar after suction, as has been the case up to now in the art, a media stream is output via the spray arrangement on one of the tools at a definable distance between the pre-press tool and the suction tool. Since the two tools are coordinated with one another with regard to the design of the products to be manufactured, the media stream in the edge area always hits a corresponding edge area of ​​the opposite tool. Furthermore, the orientation of outlets, e.g.of nozzles, the spray arrangement and the amount of medium dispensed can be specifically tailored to the design of the other tool.

[0020] In further embodiments, the spray arrangement can have outlets arranged at regular intervals so that uniform spraying can take place.

[0021] In further embodiments, the spray arrangement can have a common reservoir for providing a medium for the outlets (e.g. nozzles) so that pressure equalization is provided and the pressure or the media output is uniform at all outlets.

[0022] In further embodiments, the spray arrangement can have at least one supply to the reservoir. In yet further embodiments, multiple supply lines can be provided, which are distributed evenly, preferably symmetrically, so that the discharge of a uniform media flow at all outlets is further supported.

[0023] In further embodiments, the spray arrangement can have at least one deflection arrangement for deflecting and / or fanning out an exiting media stream. The deflection arrangement can, for example, have a deflection tongue. This allows for the fanning out of a media stream. Furthermore, the direction of the discharged media stream can be determined with respect to the design of a corresponding tool (opposite tool).

[0024] In further embodiments, the deflection arrangement can have a continuous deflection edge running parallel to the edge region of the molded body. The deflection arrangement can, for example, have a circumferential deflection edge. The deflection edge can be designed such that a circulating media stream is discharged via outlets of the spray arrangement, which impinges essentially evenly on the edge region of an opposing tool like a "curtain."

[0025] In further embodiments, the deflection arrangement can have a deflection angle for a media flow exiting the spray arrangement of 0 to 85° relative to the exit direction.

[0026] In further embodiments, the deflection arrangement can have a plurality of deflection tongues. Each outlet (e.g., nozzle) can be assigned a deflection tongue. The exiting and deflected or fanned-out media streams can overlap in certain areas, forming a "curtain" overall.

[0027] In further embodiments, outlets can be formed as holes in the spray arrangement and / or the outlets can be nozzles, in particular dual-fluid nozzles and / or tongue nozzles. The design of outlets as holes enables a customized and simple configuration. For example, holes can be introduced into a ring that has a common supply line (reservoir) for a medium. The arrangement and design of the openings (diameter, cross-section, exit angle, and orientation relative to an opposite spray surface) can be specifically adapted. Tongue nozzles have the advantage of allowing a fanning out of an exiting media stream.

[0028] In further embodiments, the molded body can have a wiper lip in the edge area. Such a wiper lip enables, for example, the stripping of protruding fibers when closing the pre-pressing tool of a pre-pressing station, wherein a pre-pressing tool with at least one pre-pressing body and a suction tool with at least one suction body are moved relative to one another. As the distance between the suction body and the pre-pressing body decreases, a circumferential wiper lip, which can be made of a flexible material (e.g. silicone), can come into contact with the edge area of ​​the suction body in the edge area. Any remaining fibers that protrude beyond the edge area of ​​a suction surface of the suction body after spraying are stripped off and the edge of the fiber cake is pressed. A suction tool usually has a suction surface with a plurality of openings through which the fibers and the liquid from a pulp are sucked in.The sucked-in liquid is discharged via channels in the suction tool. A ring surrounds the suction surface at the edge, with the inner surface of the ring defining the outer edge of the fiber cake / preform and thus of the product to be manufactured. The wiper lip can have an outer diameter that essentially corresponds to the inner diameter of the ring, allowing the wiper lip to dip into the ring and strip the fibers, as well as compress the edge of the fiber cake. To facilitate the "dipping" of the wiper lip into the ring, the ring can have a dipping area with a larger diameter. The wiper lip can have a varying diameter at its outer edge in relation to the closing direction, thereby assisting the stripping and compressing of fibers. In other designs, the height of the wiper lip can be at least as large as the height of a ring in the closing or pressing direction.

[0029] In further embodiments, the tool can be a pre-pressing tool for pressing three-dimensional preforms or sucked-in fibers / fiber cakes made of a fiber-containing material and the molded body can be a pre-pressing body, wherein the three-dimensional surface is a pressing surface of the pre-pressing body, and wherein the pre-pressing body consists of a flexible material (e.g. silicone or silicone-containing plastic mixture).

[0030] In further embodiments, the tool can be a suction tool for sucking fibers from a fiber-containing suspension and the molded body can be a suction body, wherein the three-dimensional surface is a suction surface of the suction body.

[0031] The above-mentioned object is also achieved by a molding system for producing fiber-containing products, comprising a pre-pressing station for pressing three-dimensional preforms made of a fiber-containing material with at least one pre-pressing tool and a suction station with at least one suction tool, wherein at least one spray arrangement is arranged on the at least one pre-pressing tool or the at least one suction tool and outlets of the at least one spray arrangement are aligned with an edge region of the at least one opposite suction tool or the at least one opposite pre-pressing tool.

[0032] A molding system with an integrated spray assembly in a tool (suction tool or pre-compression tool) offers the advantages described above and enables faster processing by shortening the cycle time, because spraying takes place during the closing process of a suction tool and a pre-compression tool. In the prior art, spraying takes place as a separate process step, which requires cycle time. Furthermore, the integration of the spray assembly offers optimal alignment and spraying of fibers, because there is no overspray of areas that are not needed (e.g. underside of the support plate of the tool and fiber cake outside the edge area). In addition, the outlets of a spray assembly can be specifically aligned and designed to suit the design of suction bodies and individually for products without compromise solutions.

[0033] In further embodiments, a molding system may comprise at least one pre-pressing tool designed according to one of the above embodiments or at least one suction tool designed according to one of the above embodiments.

[0034] In further embodiments, a molding system can have a device for supplying media, which has at least one actuator for controlling the supply of media to the at least one spray arrangement. The at least one actuator is arranged directly upstream of a reservoir for providing a medium within the spray arrangement and / or directly upstream of openings in the spray arrangement. The actuator can be, for example, a valve, a motor, a throttle valve, etc. The direct arrangement of the actuator upstream of a reservoir or the openings of the outlets of the spray arrangement allows for rapid response of the outlets to discharge a media stream. Furthermore, this can simplify control of the actuator.

[0035] In further embodiments, the suction surface of the suction body and suction channels in the edge region for sucking in fibers can have different permeabilities for a suction effect that is reduced compared to the rest of the suction body. The different permeabilities can be achieved by a different design and distribution of openings in the suction surface (e.g. the mesh structure of a suction tool that rests against a suction surface of a suction body, whereby the suction body has suction channels). For example, the edge region of a suction surface in particular can have a smaller number of openings and / or a smaller opening width as well as different cross-sections at the openings than the rest of the area of ​​a suction surface, so that overall fewer fibers are sucked in in the edge region and there is also less protruding, excess fiber material.The area in which fewer fibers are sucked in can explicitly refer only to an outer edge section, so that the edge of a product to be formed does not necessarily have to be thinner than the rest of the product.

[0036] The above-mentioned object is also achieved by a method for producing fibrous products, comprising a pre-pressing station for pressing three-dimensional preforms made of a fibrous material with at least one pre-pressing tool and a suction station with at least one suction tool, wherein at least one spray arrangement is arranged on the at least one pre-pressing tool or the at least one suction tool and outlets of the at least one spray arrangement are aligned with an edge region of a suction body of the at least one opposite suction tool or of a pre-pressing body of the at least one opposite pre-pressing tool, wherein a medium (media flow) is cyclically discharged via the outlets in accordance with a control via an actuator when the distance between the suction surface of the suction tool and the pressing surface of the pre-pressing tool reaches a value between 1 and 30 mm.

[0037] The fibers in the edge area of ​​an opposing tool are sprayed off before the surfaces of the opposing tools touch each other. The discharge of a medium via the outlets (e.g., nozzles) can also be terminated before the surfaces of the opposing tools touch each other. The distance between the tools allows the edge area of ​​an opposing tool to be exposed to a uniform media flow, while the influence of overlaps of the media flows from adjacent outlets, especially in the case of fan-shaped media flows, on the overall media flow is minimal.

[0038] In other versions, the media stream can be output as a flat jet.

[0039] In further embodiments, the relative pressure for providing the media flow can be between 0.1 and 10 bar, preferably between 1 and 3 bar.

[0040] In further embodiments, the media flow can be discharged for a period of 0.5 to 5 seconds based on a relative movement of the pressing surface of the pre-pressing body of the at least one pre-pressing tool and the suction surface of the suction body of the at least one suction tool. In further embodiments, the duration and pressure of the media flow discharge are determined based on the distance between opposing surfaces of the tools involved.

[0041] The solution presented here enables material savings in the production of products made from fibrous materials, as only as much material (fibers) is sucked into the edge as is actually needed. Furthermore, a faster production process is achieved, as no interruption / waiting time is required, as is the case with conventional spray bars from the state of the art. Furthermore, less water is consumed, as the spraying is targeted. Furthermore, there is no contamination of a forming line or dilution of the pulp by bouncing or dripping spray water, as is the case with spray bars in the state of the art. Furthermore, a punch is no longer required, as perfect edge quality is achieved. Finally, a stable edge is provided, as the edge is formed, i.e., the fibers in the edge are bound, with a punch creating "angel hair" (loose fibers).

[0042] Further features, embodiments and advantages emerge from the following presentation of embodiments with reference to the figures. Short description of the characters

[0043] In the drawings shows: Fig. 1 shows a schematic representation of a molding system for producing products from a fiber material; Fig. 2 shows a schematic representation of a suction tool and a pre-pressing tool in section; Figs. 3-7 show various designs of nozzle arrangements on a suction tool or a pre-pressing tool; Fig. 8 shows a schematic representation of an embodiment of a nozzle arrangement on a pre-pressing tool; Figs. 9-11 show various representations of an embodiment of a nozzle arrangement on a pre-pressing tool; Fig. 12 shows schematic representations of the formation of a tongue and the medium discharged via the nozzle arrangement; Fig. 13 shows a method for producing three-dimensional products from a fiber-containing material. Detailed description of implementation examples

[0044] The following figures illustrate exemplary embodiments of the technical teaching described herein with reference to the figures. The same reference numerals are used for identical components, parts, and processes in the description of the figures. Components, parts, and processes that are not essential to the technical teaching disclosed herein or that would be obvious to a person skilled in the art are not explicitly reproduced. Features stated in the singular are also included in the plural, unless explicitly stated otherwise. This applies in particular to statements such as "a" or "an." The exemplary embodiments shown do not represent any limitation with regard to further developments and modifications of the described embodiments.

[0045] Fig. 1shows a schematic representation of a molding system 1000 for producing three-dimensional products from a fiber material. The fiber material for production can be provided by a fiber processing system and made available to the molding system 1000. The provision and making available can be effected, for example, via supply lines through which liquid pulp from a fiber processing system is fed, for example, continuously or discontinuously, to a storage container or a pulp basin 200 of the molding system 1000. Alternatively, pulp can be processed in a pulp basin 200 of the molding system 1000. For this purpose, water and fiber materials, as well as any additives, can be introduced into a pulp basin 200 via a liquid supply, and the pulp can be processed in the pulp basin 200 by mixing the individual components with the introduction of heat and using aids such as a stirrer.

[0046] Pulp is an aqueous solution containing fibers, with the fiber content of the aqueous solution ranging from 0.5 to 10% by weight. It may also contain additives such as starch, chemical additives, wax, etc. The fibers can be natural fibers, such as cellulose fibers, or fibers from a fibrous source material (e.g., waste paper).

[0047] The 1000 molding system can be used to produce, for example, biodegradable cups, capsules, 3000 bowls, plates, and other molded and / or packaging parts (e.g., as holder / support structures for electronic devices). Since the raw material for these products is a fibrous pulp containing natural fibers, the products produced in this way can be reused as raw material for the production of similar products or composted after use, as they are generally completely degradable and do not contain any harmful, environmentally hazardous substances.

[0048] The Fig. 1The molding system 1000 shown has a frame 100, which can be surrounded by a casing. The supply units 300 of the molding system 1000 include, for example, interfaces for the supply of media (e.g., water, pulp, compressed air, gas, etc.) and energy (power supply), a central control unit 310, at least one suction device 320, line systems for the various media, pumps, valves, lines, sensors, measuring devices, a BUS system, etc., as well as interfaces for bidirectional communication via a wired and / or wireless data connection. Instead of a wired data connection, a data connection via a fiber optic cable can also be used. The data connection can, for example, exist between the control unit 310 and a central control system for several molding systems 1000, to a fiber processing system, to a service center, and / or other facilities.The molding system 1000 can also be controlled via a bidirectional data connection using a mobile device such as a smartphone, tablet computer or the like.

[0049] The control unit 310 communicates bidirectionally with an HMI panel 700 via a bus system or a data connection. The HMI (Human-Machine Interface) panel 700 has a display that shows operating data and states of the molding system 1000 for selectable components or the entire molding system 1000. The display can be designed as a touch display, so that settings can be made manually by an operator of the molding system 1000. Additionally or alternatively, further input devices, such as a keyboard, a joystick, a keypad, etc., can be provided on the HMI panel 700 for operator inputs. These can be used to change settings and influence the operation of the molding system 1000.

[0050] The molding system 1000 has a robot 500. The robot 500 is designed as a so-called 6-axis robot and is therefore able to pick up parts, rotate them, and move them in all spatial directions within its operating radius. Instead of the Fig. 1 In addition to the robot 500 shown, other handling devices can also be provided, which are designed to pick up products and twist or rotate them and move them in various spatial directions. Furthermore, such a handling device can also be designed differently, whereby the arrangement of the corresponding stations of the molding system 1000 can differ from the illustrated embodiment.

[0051] A suction tool 520 is arranged on the robot 500. In the exemplary embodiment shown, the suction tool 520 has cavities designed as negatives of the three-dimensional molded parts to be formed, such as cups 3000, as suction cavities. The suction cavities can, for example, have a net-like surface as suction surface 532, to which fibers from the pulp adhere during suction. Behind the net-like surfaces, the suction cavities are connected to a suction device via suction channels 536 in the suction tool 520. The suction device can, for example, be realized by a suction device 320. Pulp can be sucked in via the suction device if the suction tool 520 is located within the pulp basin 200 such that the suction cavities are at least partially located in the aqueous fiber solution, the pulp. A vacuum orA negative pressure for sucking in fibers when the suction tool 520 is located in the pulp tank 200 and the pulp can be provided via the suction device 320. For this purpose, the molding system 1000 has corresponding means at the supply units 300. The suction tool 520 has lines for providing the vacuum / negative pressure from the suction device 320 at the supply units 300 to the suction tool 520 and the openings in the suction cavities. Valves are arranged in the lines, which can be controlled via the control unit 310 and thus regulate the suction of the fibers. Instead of suction, the suction device 320 can also "blow out" the fibers, for which purpose the suction device 320 is switched to a different operating mode depending on its design.

[0052] During the production of molded parts from a fiber material, the suction tool 520 is immersed in the pulp and a negative pressure / vacuum is applied to the openings of the suction cavities so that fibers are sucked out of the pulp and deposited on the suction surface 532, for example on the mesh, of the suction cavities of the suction tool 520.

[0053] The robot 500 then lifts the suction tool 520 from the pulp tank 200 and moves it, along with the fibers adhering to the suction surfaces 532, which still have a relatively high moisture content of, for example, over 80% by weight of water, to the pre-press station 400 of the molding system 1000, wherein the negative pressure in the suction cavities is maintained for transfer. The pre-press station 400 has a pre-press tool 410 with pre-press bodies. The pre-press bodies can, for example, be designed as a positive of the molded parts to be produced and can have a size appropriate to the shape of the molded parts to accommodate the fibers adhering in the suction cavities.

[0054] During the manufacture of products, the suction tool 520, with the fibers adhering to the suction cavities, is moved to the pre-pressing station 400 so that the fibers are pressed into the suction cavities. The fibers are pressed together in the suction cavities, creating a stronger bond between the fibers. Furthermore, the moisture content of the preforms formed from the sucked-in fibers is reduced, so that the preforms formed after pre-pressing only have a moisture content of, for example, 60% by weight. Flexible pre-pressing bodies can be used to press out water. These bodies are inflated, for example, using compressed air (process air), thereby pressing the fibers against the suction surface 532 of the suction cavities. This "inflating" both presses out water and reduces the thickness of the sucked-in fiber layer. The liquid orPulp is sucked out via the suction tool 520 and can be reused, for example.

[0055] After pre-pressing in the pre-press station 400, the preforms thus produced are moved on the suction tool 520 via the robot 500 to a hot-press station 600, which has a mold 610 for the final shaping and drying of the preforms into three-dimensional products. For this purpose, the negative pressure is maintained at the suction tool 520 so that the preforms remain in the suction cavities. The preforms are transferred via the suction tool 520 to a lower tool body of a first tool component of the mold 610, which can be moved along the production line from the hot-press station 600. When the lower tool body is in its extended position, the suction tool 520 is moved to the lower tool body so that the preforms can be placed on molding devices or molded parts of the lower tool body.Subsequently, positive pressure is generated via the openings in the suction tool 520, so that the preforms are actively deposited from the suction cavities in the suction tool 520, or the suction is terminated, so that the preforms remain on the mold devices or mold parts of the lower tool body due to gravity. By providing positive pressure at the openings of the suction cavities of the suction tool 520, pre-pressed preforms that are resting / adhering in the suction cavities of the suction tool 520 can be released and dispensed.

[0056] Thereafter, the suction tool 520 is moved away from the robot 500 and the suction tool 520 is immersed into the pulp tank 200 to suck in further fibers for producing molded parts from fibrous material.

[0057] After the preforms have been transferred, the lower tool body of the mold 610 moves to the hot-pressing station 600. In the hot-pressing station 600, the preforms are pressed into finished products under heat input and high pressure. For this purpose, an upper tool body of a second tool component of the mold 610 is brought onto the lower tool body via a press. The upper tool body has cavities corresponding to the molding devices or molded parts. After the hot-pressing process, the lower tool body and the upper tool body are moved away from one another, and the upper tool body is moved along the molding system 1000 in the production direction. After the hot-pressing process, the finished products are sucked in via the upper tool body and thus remain within the cavities.Thus, the finished products are removed from the hot-pressing station 600 and, after the movement, deposited on a conveyor belt of a conveyor device 800 via the upper tool body. After depositing, the suction via the upper tool body is terminated, and the products remain on the conveyor belt. The upper tool body returns to the hot-pressing station 600, and another hot-pressing process can be performed.

[0058] The molding system 1000 further comprises a conveyor system 800 with a conveyor belt. After final molding and hot pressing in the hot-pressing station 600, the finished products made of fibrous material can be placed on the conveyor belt and removed from the molding system 1000. In further embodiments, after the products have been placed on the conveyor belt of the conveyor system 800, further processing can take place, such as filling and / or stacking the products. Stacking can be performed, for example, by an additional robot or another device.

[0059] The molding system 1000 from Fig. 1shows a possible embodiment. A molding system according to the technical teaching described herein can also have only one molding station with an interchangeable tool, for example a suction tool 520 or a hot-pressing tool in which fibrous material can be processed, wherein various tools for producing different three-dimensional products can be accommodated in the at least one molding station. The further features of the molding system 1000 of Fig. 1 The stations and devices shown are not absolutely necessary for the implementation of the technical teaching.

[0060] Fig. 2 shows a schematic representation of a suction tool 520 and a pre-pressing tool 410 in a sectional view, showing the rough structure. A spray arrangement designed as a nozzle arrangement 900 for spraying fibers is described below with reference to Fig. 3 to 13 described in detail.

[0061] The suction tool 520 has a base body with a support plate 522, on which a suction body 530 is arranged. The suction body 530 has suction channels 536 on openings 534 that extend over the surface or the suction surface 532. The suction channels 536 and the openings 534 are connected to one another and serve to suck in fibers when the suction tool 520 is immersed in a pulp. Furthermore, a fiber cake of sucked-in fibers that deposit on the suction surface 532 can be held in the suction cavity by maintaining a negative pressure via the openings 534 and suction channels 536. In further embodiments, a net or similar structure can be arranged on the inner surface of the suction body 530, which then serves as the suction surface 532 and to which the fibers deposit.The arrangement and design of a network, the openings 534, and the suction channels 536 are selected such that fewer fibers are sucked in in the outer edge region of the suction surface 532 than in the remaining area of ​​the suction surface 532. The outer edge region is the area in the immediate vicinity of a ring 540. The ring 540 surrounds the suction surface 532 and defines the outer edge of a product to be formed. There may be fewer openings 534 and suction channels 536 in the outer edge region, and / or the diameters of the openings 534 and the suction channels 536 may be smaller than in the remaining area of ​​the suction surface 532. In further embodiments, additionally or alternatively, a network or a similar structure in an outer edge region of a suction surface 532 may have a smaller number of openings, or fewer areas may be designed in a network-like manner.

[0062] The ring 540 defines an outer edge for a product to be molded on its inner circumference. In an entry area for a silicone body 426 of the pre-press tool 410, the ring 540 has a stripping edge 542. The stripping edge 542 extends over the entire circumference of the ring 540.

[0063] The components of the suction tool 520 can, for example, consist of a metal (e.g., aluminum) or a metal alloy.

[0064] The pre-pressing tool 410 has a support body 420 made of a metal (e.g., aluminum) or a metal alloy. In a pre-pressing region of the pre-pressing tool 410, the support body 420 has an elevation on which a silicone body 426 is arranged. The silicone body 426 and the support body 420 together form a pre-pressing body for a pre-pressing tool 410. The support body 420 has an air channel 422 in its interior, which merges into secondary channels so that by providing a medium, such as compressed air, the silicone body 426 can be inflated, thereby exerting additional pressure on the fiber material in the cavity of the suction tool 420 for pressing and dewatering the fiber cake. The silicone body 426 can also be perforated. The support body 420 is connected to a carrier plate 412 of the pre-pressing tool 410.Instead of a silicone body 426, a pre-compressed body can comprise a flexible material that has the same properties as silicone and expands upon application of pressure. For this purpose, thermoplastic elastomers or other materials can be used.

[0065] On the upper outer circumference, the silicone body 426 has a wiper lip 430. This wipes when closing the Fig. 2The components shown, pre-compression tool 410 and suction tool 520, cut off fibers protruding beyond the edge region of the suction surface 532 or the ring 540, and can push fibers specifically into the edge region of the suction surface 532. The flexibility of the silicone body 426 supports the stripping and pushing of fibers in this area. Furthermore, this achieves a compression or pre-compression, so that any deficit in fibers in the outer edge region of the suction surface 532 is compensated for by "edge" fibers that are pushed over the stripping lip 430 along the stripping edge 542 into the outer edge region. After reaching a final position, the fibers are compressed via the silicone body 426.

[0066] In further embodiments, a suction tool 520 can be designed as a multi-cavity tool and have a plurality of suction bodies 530. A corresponding pre-press tool 410 can also be designed as a multi-cavity tool and have a corresponding plurality of pre-press bodies or silicone bodies 426 and support bodies 420.

[0067] In the following, embodiments of spray arrangements are described which, in the embodiments shown, are designed as nozzle arrangements 900, wherein in further embodiments, spray arrangements can also have other outlets such as the nozzles 922 shown.

[0068] The Fig. 3-7 show various designs of nozzle arrangements 900, such as can be designed for spraying fibers. A nozzle arrangement can be provided on a suction tool 520 or a pre-pressing tool 410.

[0069] Fig. 3shows an embodiment with a nozzle arrangement 900 on a pre-press tool 410, wherein nozzles of the nozzle arrangement 900 are provided in an edge region of the silicone body 426. For this purpose, the silicone body 426 is open in sections so that the circumferentially provided nozzles can dispense a medium which, in order to spray fibers in the stripping area of ​​the ring 540, impinges on the ring 540 and the stripping edge 542. The nozzle arrangement 900 has a plurality of nozzles or a circumferential nozzle slot. The nozzles are designed as bores in a nozzle ring which runs in the edge region of the silicone body 426. Below the nozzle ring, an annular reservoir 928 is located in the support body 420. The reservoir 928 is connected to a connection for the media supply and serves to equalize the pressure across all nozzles of the nozzle arrangement. Due to the design of the embodiments shown, concentric pressure equalization takes place here via the reservoir 928.In addition, pressure loss regulation is achieved via the reservoir 928.

[0070] Fig. 4 shows an embodiment with a nozzle arrangement 900 comprising a nozzle ring 920 provided on the outer edge of a silicone body 426 of a pre-pressing tool 410. The nozzle ring 920 has a reservoir 928 for providing a medium for spraying fibers. Furthermore, the nozzle ring 920 has a plurality of nozzles 922 or a circumferential nozzle slot. The nozzle arrangement 900 has a deflection device for deflecting the media stream discharged via the nozzles 922, wherein the surface of the silicone body 426 does not require any openings for the nozzle arrangement 900 and thus the pressing surface of the silicone body 426 is not reduced. As shown, a media stream can be discharged onto the stripping area of ​​the ring 540 via this.

[0071] Fig. 5shows an embodiment with a nozzle arrangement 900, which has a nozzle ring arranged on the support body 420 of the pre-pressing tool 410. The arrangement and design of the nozzle ring of Fig. 5 differs from the execution according to Fig. 4 in particular in that the discharged media stream or jet is not deflected by a deflection device, but essentially hits the opposite stripping area of ​​the ring 540 in a straight line.

[0072] Fig. 6 shows a design with a nozzle arrangement 900 integrated into the suction tool 520. The nozzle arrangement is formed in the suction body 530 and, in addition to the reservoir 928, has a plurality of nozzles or a circumferential nozzle slot, which open at an outer edge into the edge region of the suction surface 532 and can directly spray off protruding fibers.

[0073] Fig. 7shows a design with a nozzle arrangement 900, which is arranged on the outside of the ring 540 on the suction tool 520 and can have a plurality of nozzles or a circumferential nozzle slot. The nozzles are directed toward the suction surface 532 or the interior of the suction cavity, so that fibers in the stripping area of ​​the ring 540 can be flushed into the suction cavity. Additional medium, such as water, can be sucked away via the openings 534 and suction channels 536.

[0074] The Fig. 3 to 7The designs shown have the advantage that, compared to known systems for spraying fibers from the prior art, such as spray bars, a medium is only introduced into the area actually required, and the jet is adapted to the respective geometry, so that a significant improvement can be achieved with fewer resources (e.g., spray medium). Furthermore, the designs shown allow spraying during an already occurring closing movement of two corresponding tools, suction tool 520 and pre-press tool 410, so that no additional time is required for spraying, as is absolutely necessary, for example, with a spray bar.

[0075] Fig. 8 shows a schematic representation of an embodiment of a nozzle arrangement 900 on a pre-press tool 410, which is based on the in Fig. 4 The concept shown is based on Fig. 8a more detailed illustration of a nozzle ring 920 having a plurality of nozzles 922 arranged evenly at defined intervals. The nozzles 922 are connected to a reservoir 928, which has at least one connection 924 (see Fig. 9-11 ) is supplied with a medium. In the supply to the connection 924, there is at least one actuator, e.g., a valve, which is arranged directly upstream of the reservoir 928 to ensure rapid response when the valve is opened or closed. In further embodiments, a reservoir 928 can be arranged below the support body 420. In still further embodiments, nozzles 922 can be oriented straight upward, ie, vertically.

[0076] The nozzle arrangement 900 has a tongue ring 930, which serves as a deflection arrangement for the medium exiting from the nozzles 922. In the illustrated embodiment, the nozzles 922 are designed as bores, so that a substantially straight jet of medium initially exits them. For spraying, it is advantageous if this occurs completely around the circumference, whereby a water jet or the like not only hits certain areas, but also forms a closed spray wall as a "curtain." Especially for products with a round cross-section, as shown here in the figures, the formation of a spray wall is a challenge, which can be solved by the tongue ring 930. The designs and effects of a tongue ring 930 are described in Fig. 12described. The nozzle ring 920 and the tongue ring 930 surround the support body 420 circumferentially. In further embodiments, the nozzle ring 920 and the tongue ring 930 can be designed as a single piece. In further embodiments, the nozzle ring 920 and / or the tongue ring 930 can also be formed together with a support body 420.

[0077] Tongue ring 930 and nozzle ring 920 can be made of a metal (e.g. aluminum) or a metal alloy.

[0078] The Fig. 9-11 show various representations of a further embodiment of a nozzle arrangement 900 on a pre-press tool 410, which is based on the in Fig. 4 concept shown and which is Fig. 8 shown components of a nozzle arrangement 900.

[0079] The pre-pressing tool 410, consisting of the silicone body 426 and the support body 420, forms a pressing surface 428 on the surface of the silicone body 426 for compacting and dewatering a fiber cake, which is provided in a suction cavity of a suction tool 520. The geometry of the pre-pressing tool 410 and in particular of the silicone body 426 essentially corresponds to the geometry of the product to be molded.

[0080] Inside, the support body 420 has at least one air channel 422 for supplying a gas or gas mixture (e.g., air), by means of which the silicone body 426 can expand ("be inflated") due to its elastic design and, when the pre-pressing tool 410 and the suction tool 520 are closed, exerts additional pressure on the fiber cake in the suction cavity. In the unpressurized state, i.e., when no gas or gas mixture is introduced, the silicone body 426 rests against the outer surface of the support body 420.

[0081] The silicone body 426 is connected to the tongue ring 930 via a tongue and groove connection with a suitable profile (e.g., dovetail profile). The tongue ring 930 rests on the support body 420 and is connected to it as well as to the nozzle ring 920, which surrounds the tongue ring 930, the support body 420, and the silicone body 426 on the circumference. The nozzle ring 920 has a plurality of nozzles 922 arranged regularly on the circumference. The nozzles 922 are designed as bores. Depending on the dimensions of the tool and the product to be manufactured, the bores have a diameter of 0.5-1.5 mm. Furthermore, the medium used and the distance between a pressing surface 428 and a suction surface 532, at which the spraying is to take place, as well as the heights H 1 , H 2 (see Fig. 12 ). In the version shown by Fig. 9-11The nozzles 922 have a length of approximately 8 mm and a diameter of 0.8 mm. The illustrated embodiment for a product or fiber cake with a diameter of approximately 60 mm has a total of 36 evenly distributed holes as nozzles 922. In further embodiments, dual-fluid nozzles can also be provided instead of holes, so that, for example, an air-water mixture is dispensed as a medium via the nozzle arrangement 900.

[0082] The nozzles 922 open into a reservoir 928, which is connected to at least one connection 924. The design in the Figures 9 to 11has four evenly distributed connections 924 for media supply. In further embodiments, the number of connections 924 may also differ from that shown, whereby, for example, only one connection 924 may be provided. The other end of the nozzles 922 for the media output is directed towards a deflection surface 934 of the tongue ring 930, which serves to deflect and fan out the dispensed medium. Fanning out of the medium along the deflection surface 934 is achieved by the rounding of the tongue ring 930 (see Fig. 12 ).

[0083] As in Fig. 10 As shown further, an upper tongue edge of the tongue ring 930 protrudes radially from the wiper lip 430 extending above it, so that a fanned-out jet 940 cannot strike the wiper lip 430 and the silicone body 426.

[0084] The height of the section of the silicone body 426, which runs from the upper edge of the tongue to the stripping lip 430, is relatively high, so that, on the one hand, the relative displacement of the pre-pressing tool 410 and the suction tool 520 during closing allows for early stripping of fibers, and, on the other hand, so that a sufficiently large, compressible buffer for pressing in the edge area is present. A corresponding height for this section can, for example, be 0.8 to 0.9 times the height of the deflection surface 934. The deflection surface 934 has a length of 5-30 mm, depending on the design of the tool and the product to be manufactured, whereby in the illustrated embodiment, the Fig. 9-11 the length of the deflection surface is 934 5 mm.

[0085] From the presentation of Fig. 11The formation of channels 910 is shown, which extend circumferentially in regular sections around an outer edge region of the nozzle ring 920 of the nozzle arrangement 900. The outer edge region of the nozzle ring 920 surrounds a groove 912, into which the ring 540 can be immersed when the pre-press tool 410 and the suction tool 520 are closed. In addition, water pressed out of the fiber cake and spray water can be drained away via the groove 912. As a rule, however, spray water that hits the edge region of a fiber cake in the edge region of the suction surface 532 is sucked away via the openings 534 and suction channels 536 and thus cannot reach the machine room of a molding system 1000 or a pulp basin 200, which would affect the concentration of the pulp or contaminate the molding system. The pre-pressing tool 410 with the nozzle arrangement 900 can be fastened to a support plate 412 by means of screws via the indicated holes.

[0086] Fig. 12 shows schematic representations of the formation of a tongue 932 and the dispensed medium via the nozzle arrangement 900. The embodiments shown in the figures refer to essentially rotationally symmetrical products and correspondingly designed tool components. However, spraying of edge areas can also occur with straight edge areas, in which case, for example, special tongue nozzles or other devices, such as deflection surfaces, can be provided to form a "jet wall" of medium. Due to the curvature in the edge area, the embodiments described here require a corresponding deflection of the dispensed medium in addition to a fanning out to provide a flat jet.

[0087] A flat jet is achieved by the curvature of the deflection surface 934 parallel to the vertical axis through the air duct 422 together with the radius of the tongue ring 930, which runs concentrically around the vertical axis. The medium striking the deflection surface 934 is deflected in two directions by the curvature of the deflection surface 934, as the medium follows the curvature of the surface it strikes. The upper part of the tongue ring 930 has a sharp separation edge, referred to as tongue 932, which ensures that the deflection of the jet 940 is maintained at an angle η. The angle η is between 30° and 45°, depending on the design and dimensions of the tools and the products to be manufactured. In the illustrated embodiment, the angle η is approximately 36°.

[0088] The lower illustration of Fig. 12shows a schematic representation of the lateral deflection of the medium, whereby a fan-like jet formation results from the nozzles 922 due to the curvature of the deflection surface 934. This results in overlaps between adjacent jets 940 in regions 950. However, at the edges of a jet 940, this is weaker than in the central region, so that the overlap has no negative effects and thus an essentially uniform jet (pressure) is output over the entire length of the common jet, i.e., the jet wall. For this purpose, the formation of the curvature or deflection via the deflection surface 934 must be adjusted accordingly. As a rule, a lateral fanning out occurs at an angle α that is greater than 50°. The total deflection can be determined with respect to a height H 1 between the outlet opening of nozzles 922 to a contact point, ie surface of the fiber material in the intake cavity in the edge region, or between the upper tongue edge orTear-off edge for the jet 940 and the surface of the fiber material in the intake cavity in the edge area.

[0089] The parameters for the design of the nozzle arrangement 900 and the heights H 1 , H 2 as well as the spraying duration, the pressure and the starting point of the start of the spraying in relation to the distance between the pressing surface 428 and the surface of the fiber material in the suction cavity in the edge region during a closing movement must be determined and specified depending on the design and dimensions of the products. Furthermore, the closing speed must be adapted and coordinated with the spraying (starting point, duration, pressure, medium). In the embodiment shown, for example, with water as the medium, a spray pressure of approximately 3 bar can be set and the spraying can take place for approximately 1 second. The distance between the surface of the fiber material in the suction cavity in the edge region and the corresponding pressing surface 428 is preferably 5 mm, wherein the distance with regard to the start of the spraying orthe media output can be started when such a distance is reached and stopped when the distance is less than 5 mm, or the media output can be started before the distance of 5 mm is reached and stopped when the distance of 5 mm is reached.

[0090] In other embodiments, the distance can be greater or less than 5 mm, depending on the design of the products to be manufactured and the resulting tool design. Preferably, such a distance is in the range between 3 and 15 mm, whereby a sufficient spraying effect can be achieved, taking into account the deflection of the flat jet.

[0091] Fig. 13 shows a method 2000 for producing three-dimensional products from a fibrous material. The method 2000 can be carried out, for example, in a Fig. 1 The molding system 1000 shown can be used.

[0092] Upstream process steps include the provision of pulp and the tool components, as well as a tool change if necessary, for producing the three-dimensional products. Subsequently, in process step 2010, fibers are sucked out of the pulp, whereby a suction tool 520 with suction bodies 530, which form suction cavities, is immersed in the pulp. During suction, by providing a negative pressure via openings 534 and suction channels 536 of the suction tool 520, fibers are deposited on the suction surface 532. Suctioned water is discharged via the openings 534 and channels 536.

[0093] After the fibers have been sucked in, in a method step 2020, the suction tool 520 is moved out of the pulp and to a pre-press station 400, wherein the fiber cake formed by the sucked-in fibers remains in the suction cavities by maintaining the negative pressure. During this or thereafter, the suction tool 520 is aligned with a pre-press tool 410, which has pre-press bodies corresponding to the suction cavities. Subsequently, in a method step 2030, the suction tool 520 is displaced relative to the pre-press tool 410, wherein the distance between the surface of the fiber cake in the suction cavities and an opposite pressing surface 428 of the pre-press bodies is continuously reduced.After reaching a minimum distance between the free surface of the fiber cake in the intake cavities and the opposing pressing surface 428 of the pre-pressing bodies, a medium is discharged via a nozzle arrangement 900 in the edge region of the pre-pressing bodies. This medium, as a jet wall, strikes an opposite stripping edge 542 of the respective intake tool 520 at an adjustable angle, thereby flushing fibers into the edge region of the fiber cake depending on their orientation and arrangement. The discharge of the medium is maintained for a definable period of time, e.g., 1 to 3 seconds at a relative pressure of 3 to 5 bar.Before the distance between the free surface of the fiber cake and the opposite pressing surface 428 of the pre-press body approaches "0" and the fiber cake touches the pressing surface 428, the spraying is terminated and a stripping lip 430 of the pre-press body touches the stripping edge 542 of the suction cavities in a process step 2050, so that fibers are additionally pushed into the edge region of the fiber cake via the stripping lip 430. For this purpose, the stripping lip 430 is elastic and can be compressed or deformed and moved along the stripping edge 542, which preferably has a slope of at least 45 degrees (see . Fig. 2 to 7 ), be moved.

[0094] The fibers are then compressed in the intake cavities between the intake surfaces 532 and the pressing surfaces 428. Additionally, a gas or gas mixture can be introduced into the pre-compression bodies via an air channel 422, causing the silicone bodies 426 of the pre-compression bodies to expand and exert additional pressure on the fiber material in the intake cavities to dewater the fiber cake and compact the fibers. At the same time, any discharged water is sucked away via the openings 534 and intake channels 536 for removal.

[0095] Subsequently, in a method step 2060, the two tools, suction tool 520 and pre-pressing tool 410, are opened, and the thus pre-pressed preforms made of fibrous material in the suction cavities are transferred via the suction tool 520 in a method step 2070 to another station, such as a hot-pressing station 600 with a molding tool 610. After the hot-pressing, further molding steps and, if necessary, further processing steps can be carried out. List of reference symbols

[0096] 100Frame 200Pulp basin 300Supply units 310Control unit 320Suction device 400Pre-press station 410Pre-press tool 412Carrier plate 420Support body 422Air duct 426Silicone body 428Pressing surface 430Wiper lip 500Robot 520Suction tool 522Carrier plate 530Suction body 532Suction surface 534Opening 536Suction duct 540Ring 542Wiper edge 600Hot-press station 610Forming tool 700HMI panel 800Conveyor device 810Camera 900Nozzle arrangement 910Channel 912Gutter 920Nozzle ring 922Nozzle 924Connection 928Reservoir 930 Tongue ring 932 Tongue 934 Deflection surface 940 Beam 950 Area 1000 Molding system 2000 Process 2010-2070 Process steps 3000 Cup

Claims

1. Tool for processing fibrous material for the production of three-dimensional products, comprising a shaped body with a three-dimensional surface which essentially depicts the shape of a product to be shaped, wherein the shaped body has a circumferential edge region, further comprising a spray arrangement via which a medium for aligning fibers in the edge region of the shaped body and / or for aligning fibers in the edge region of an opposite tool with a further shaped body can be dispensed.

2. Tool according to claim 1, wherein the molded body and the further molded body of an opposite tool are designed differently.

3. Tool according to claim 1 or 2, wherein the spray arrangement has outlets arranged at regular intervals.

4. Tool according to one of claims 1 to 3, wherein the spray arrangement has a common reservoir for providing a medium for the outlets.

5. Tool according to claim 4, wherein the spray assembly has at least one supply to the reservoir.

6. Tool according to one of claims 1 to 5, wherein the spray arrangement has at least one deflection arrangement for deflecting and / or fanning out an exiting media stream.

7. Tool according to claim 6, wherein the deflection arrangement has a continuous deflection edge running parallel to the edge region of the molded body.

8. Tool according to claim 6 or 7, wherein the deflection arrangement has a deflection angle for a media stream exiting the spray arrangement of 0 to 85° for exit screening.

9. Tool according to one of claims 6 to 8, wherein the deflection arrangement has a plurality of deflection tongues.

10. Tool according to one of claims 1 to 9, wherein the outlets are formed as bores in the spray arrangement and / or wherein the outlets are nozzles, in particular two-component nozzles and / or tongue nozzles.

11. Tool according to one of claims 1 to 10, wherein the shaped body has a scraper lip in the edge region.

12. Tool according to one of claims 1 to 11, wherein the tool is a pre-pressing tool for pressing three-dimensional preforms made of a fibrous material and the molded body is a pre-pressing body, wherein the three-dimensional surface is a pressing surface of the pre-pressing body, and wherein the pre-pressing body consists of a flexible material.

13. Tool according to one of claims 1 to 11, wherein the tool is a suction tool for sucking fibers from a fiber-containing suspension and the molded body is a suction body, wherein the three-dimensional surface is a suction surface of the suction body.

14. Molding system for producing fiber-containing products, comprising a pre-pressing station for pressing three-dimensional preforms from a fiber-containing material with at least one pre-pressing tool and a suction station with at least one suction tool, wherein at least one spray arrangement is arranged on the at least one pre-pressing tool or the at least one suction tool and outlets of the at least one spray arrangement are aligned with an edge region of the at least one opposite suction tool or the at least one opposite pre-pressing tool.

15. Molding system according to claim 14, comprising at least one pre-pressing tool designed according to one of claims 1 to 12, or at least one suction tool designed according to one of claims 1 to 11, 13.

16. Molding system according to claim 14 or 15, comprising a device for supplying media, which has at least one actuator for controlling the supply of media to the at least one spray arrangement, wherein the at least one actuator is arranged directly in front of a reservoir for providing a medium within the spray arrangement and / or directly in front of openings of the spray arrangement.

17. Molding system according to one of claims 14 to 16, wherein the suction surface of the suction body and suction channels in the edge region for sucking in fibers have a different permeability for a suction effect that is reduced compared to the rest of the suction body.

18. A method for producing fibrous products using a molding system according to claims 14 to 17, comprising a pre-pressing station for pressing three-dimensional preforms from a fibrous material with at least one pre-pressing tool and a suction station with at least one suction tool, wherein at least one spray arrangement is arranged on the at least one pre-pressing tool or the at least one suction tool and outlets of the at least one spray arrangement are aligned with an edge region of a suction body of the at least one opposite suction tool or of a pre-pressing body of the at least one opposite pre-pressing tool, wherein a media flow is cyclically discharged via the outlets in accordance with a control via an actuator when the distance between the suction surface of the suction tool and the pressing surface of the pre-pressing tool reaches a value between 1 and 30 mm.

19. The method according to claim 18, wherein the media stream is discharged as a flat jet.

20. The method according to claim 18 or 19, wherein the relative pressure for providing the media flow is between 0.5 and 10 bar, preferably between 1 and 4 bar.

21. Method according to one of claims 18 to 20, wherein the media flow is discharged in accordance with a relative movement of the pressing surface of the pre-pressing body of the at least one pre-pressing tool and the suction surface of the suction body of the at least one suction tool for a period of 0.5 to 5 seconds.

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