Device for supplying a gas stream to a mould tool for forming moulded parts, tool comprising such a device and method for controlling the supply of a gas stream

Abstract

A device for supplying a gas stream to a tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, a tool with such a device and a method for controlling the supply of a gas stream to a tool are described.

Description

Technical area

[0001] A device for supplying a gas stream to a tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, a tool with such a device and a method for controlling the supply of a gas stream into a tool are described.

[0002] Fibrous materials are increasingly being used to produce packaging for food (e.g. bowls, capsules, boxes, etc.) and consumer goods (e.g. electronic devices, etc.) as well as beverage containers. Everyday objects such as disposable cutlery and tableware are also made from fibrous materials. Fibrous materials include natural fibers 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 raw materials or waste paper. The natural fibers are mixed with water and, if necessary, other additives such as starch in a so-called pulp. Additives can also affect the color, barrier properties and mechanical properties. This pulp can contain, for example, 0.1 to 10% by weight of natural fibers.The proportion of natural fibers varies depending on the process used to produce packaging, etc., and the product properties of the product to be manufactured. background

[0003] The production of fiber-containing products from pulp generally takes place in several work steps. For this purpose, a fiber processing facility has several stations or forming stations. In a forming station, for example, fibers can be sucked into a cavity of a suction tool, whereby a preform is shaped or formed. For this purpose, the pulp is provided in a pulp supply, and the suction tool, with at least one suction cavity whose geometry essentially corresponds to the product to be manufactured, is at least partially immersed in the pulp. During immersion, suction occurs via openings in the suction cavity, which are connected to a corresponding suction device, with fibers from the pulp collecting on the surface of the suction cavity. The sucked-in fibers or a preform can then be transferred via the suction tool into a pre-pressing tool, where the preform is pre-pressed.For this purpose, elastic molds can be used, for example, which are inflated for compression, exerting pressure on the preforms. During this pre-compression process, the fibers in the preform are compressed and the water content of the preform is reduced. Alternatively, preforms can be prepared by scooping, in which a scooping tool is immersed in the pulp, and fibers are deposited on the molded parts of the scooping tool as it is raised.

[0004] The preforms are then pressed into finished molded parts in a hot-pressing device. Preforms are inserted into a hot-pressing tool, which, for example, has a heated lower and upper tool half. Within the hot-pressing tool, the preforms are pressed between molding devices in cavities under heat input. The pressure and heat remove residual moisture, reducing the moisture content of the preforms from approximately 60% by weight before hot-pressing to, for example, 5-10% by weight after hot-pressing. The water vapor generated during hot-pressing is extracted during the hot-pressing process through openings in the cavities and channels in the hot-pressing tool.

[0005] A manufacturing method and a fiber processing device for this purpose are known, for example, from DE 10 2019 127 562 A1.

[0006] To remove hot steam, it has already been proposed to provide an additional gas stream, which is introduced into the hot-pressing tool and mixes with the steam extracted from the cavities. However, this flow causes asymmetric cooling of the hot-pressing tool and the associated molding equipment. This asymmetric cooling has a significant impact on the hot-pressing forming step, as it also severely impairs the heating of the molding equipment. As a result, the cycle time increases because the heating time for the cavities, which take the longest to return to the required temperature, determines the time. Task

[0007] In contrast, the objective is to provide a solution that provides a uniform temperature distribution in a ventilated mold. Furthermore, the objective is to resolve the problems of the state of the art and provide an alternative to known molds. Solution

[0008] The above-mentioned object is achieved by a device for supplying a gas stream to a tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, comprising first channels in a tool body of the tool in the region of forming devices for forming molded parts and at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels, wherein the diameter of the at least one second channel is greater than the diameter of the first channels.

[0009] The device achieves targeted guidance and subdivision of the guided gas flow or steam, whereby a main gas flow and secondary gas flows or main and secondary steam flows are generated in and around the tool. The first channels run in a tool body and are connected to the molding devices located above or below it via openings and, if necessary, further channels. The first channels extend within the tool body parallel to the molding surface on which molding devices are arranged or provided. Such a tool body has regions which are located below or above the molding devices and are assigned to them. The steam reaches these regions first when steam is extracted during a hot pressing process.When an additional gas stream is supplied for venting, the venting occurs according to the position of the supply point and the design of the first channels, as well as the number and size of the molding equipment and the shape of the tool body. Since the supply is usually from one side / location in the prior art, an uneven supply occurs, so that the water vapor in the tool body is dissipated at different rates through the first channels. Some areas are vented quickly and thus tend to cool down quickly, while in other areas the hot water vapor "stands" or lingers for a relatively long time, so that no cooling occurs. By means of at least one second channel, which surrounds the tool or tool body preferably in the plane of the first channels or parallel to them, the additionally supplied gas stream can, for example,on two or three sides of a mold block, so that ventilation is more evenly distributed. If the residence time of the steam discharged from the cavities or molding devices and the flow rate are determined in advance, the supply of a gas stream from the second channel to individual channels can be specifically controlled to optimize the overall flow for uniform temperature distribution.

[0010] Advantageously, the at least one second channel is designed such that it has a larger cross-section than the first channels, whereby a flow through the first channels via a gas flow supplied through the at least one second channel is regulated in a first step.

[0011] The device thus enables the subdivision of the main / secondary gas flows or steam flows by adjusting and selecting flow cross-sections, as well as by narrowing or widening them. Gas flows include both gas mixtures (e.g., air) and gases.

[0012] The subdivision of the channels in the tool and the device also means that the resulting steam, including the thermal energy stored therein, can remain in specific places without a significant increase in pressure, and the reduced flow at these places reduces the (unnecessary energy dissipation).

[0013] It is particularly important that the steam can escape from the molding devices or cavities into the periphery (tool body, base, basic structure, pipe system, hose system) without pressure or almost without pressure, whereby the steam flow is imposed on an existing air or gas flow.

[0014] This achieves a uniform temperature distribution in a tool, e.g., a hot-pressing tool for the production of molded parts from a fibrous material. This can increase the efficiency of a hot-pressing process, increase process stability, and improve the product quality of the hot-pressed molded parts. Furthermore, when designing the cross-sections for the first channels and the at least one second channel, the local cooling of molding devices and / or a tool body of the tool can be taken into account. This cooling occurs when escaping water from preforms evaporates due to the thermal energy extracted from the tool or the molding devices. This allows, for example, a tool body in particular to be kept at a substantially constant temperature during the hot-pressing process, especially over several cycles. This has a further positive effect on the above-mentioned advantages.

[0015] In further embodiments, the first channels can be interconnected at least in the areas of molding devices, so that the ventilation or flow through for targeted steam removal is improved.

[0016] In further embodiments, the at least one second channel can collectively surround all areas of the molding devices of a tool body. Preferably, the at least one second channel runs around a tool body and thus surrounds it on four sides in the case of a rectangular tool body. The at least one second channel serves not only as a channel for the collective supply of an additional gas stream but also for the removal of a saturated gas stream, wherein the saturated gas stream has absorbed water vapor from the areas of the molding devices.

[0017] In further embodiments, the connecting points between the first channels and the at least one second channel can have a smaller diameter than the first channels. The connecting points act as throttle elements and significantly influence the amount of gas flowing into the respective first channel. The connecting points can be designed differently for the first channels in order to achieve the required flow to achieve a uniform temperature distribution.

[0018] In further embodiments, the opening width of the connecting points between the first channels and the at least one second channel can be adjustable in order to be able to make adjustments, for example, during a tool change to produce different molded parts, wherein the molding devices connected to a tool body are exchanged. During such a tool change, the areas of the molding devices can change. In addition, other molding device-specific features influence the amount of steam that enters the first channels. The adaptability and changeability of the opening width thus makes it possible to take a tool change into account and also to make adjustments during tool operation if, for example, changes are detected in the finished molded parts and / or in the discharged saturated gas stream. This can be done, for example, using a control system and corresponding detection devices (camera, sensors, etc.).) a change can be detected. The control system can then, for example, control throttle valves accordingly to change the opening width. For this purpose, a camera can, for example, record the surface of the molded parts after hot pressing. Moist areas can thus be visually detected. The position of the respective molded part can be used to directly draw conclusions about the corresponding first channels or the respective area of ​​the molding device, and the corresponding throttle valves for these channels can be controlled. Machine learning can also be integrated, for example by carrying out a test run and obtaining reference data for the control system.

[0019] In further embodiments, the at least one second channel can be divided into channel sections, and the supply of a gas flow into the channel sections can be regulated. This allows the amount of gas flow primarily available and supplied to the first channels to be further controlled to achieve a uniform temperature distribution in the mold.

[0020] In further embodiments, the supply of a gas stream into the at least one second channel and / or the first channels can be controlled by throttle elements and / or conveying devices. Throttle elements can be, for example, valves or throttle flaps.

[0021] Conveying devices can be, for example, pumps or fans, which are integrated into and / or connected to the second channel. In other designs, the flow through the tool and the supply of an additional gas flow can also be controlled via a suction or negative pressure prevailing in a discharge line for saturated gas flow. Conveying devices, for example, can be used for this purpose.

[0022] In further embodiments, the device can comprise at least one device for controlling the temperature of a gas stream that can be fed into the at least one second channel and / or the first channels in order to influence the temperature of the supplied gas stream. For example, heating can occur, since warmer air, for example, can experience a higher water saturation, allowing more vapor to be removed.

[0023] In further embodiments, the first channels can comprise a number of channels extending orthogonally to one another. Ideally, the at least one second channel has large cross-sections around the tool and cross-sectional constrictions in transverse and longitudinal channels (first channels) in a tool body.

[0024] Such a device can, for example, be attached to a tool with existing first channels for flow through or be provided as an integral component of a tool.

[0025] The above-mentioned object is also achieved by a tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, comprising first channels in a tool body of the tool in the region of molding devices for forming molded parts and at least one device according to one of the above embodiments, wherein the at least one device has at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels.

[0026] A main gas flow integrated in the tool is directed in and around the tool by a targeted arrangement of channels and their cross-sections in such a way that a flowing, cold or preheated, preferably dry, draft gas flow does not asymmetrically cool a hot tool body despite uniform ventilation and thus creates a uniform temperature pattern at the cavities or mold devices.

[0027] The above-mentioned object is further achieved by a method for controlling the supply of a gas flow into a tool for forming molded parts from a fibrous material, wherein steam generated during the molding process is discharged from the molded parts pressed in the tool via channels in the tool, wherein the tool has first channels in a tool body of the tool in the region of molding devices for forming molded parts and at least one device according to one of the above embodiments is provided, wherein the at least one device has at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels, wherein the supply of a gas flow into the at least one second channel and / or the first channels is controllable via at least one throttle device and / or a conveying device.

[0028] The supplied gas / air or steam flow is directed into technically advantageous paths, since main and secondary channels are provided in the tool body of the tool, onto which the resulting steam can "jump" without pressure and according to the amount produced.

[0029] In addition to the main channels, the steam flow is specifically influenced and directed by secondary channels with cross-sectional constrictions and expansions (bore diameters, blind plugs, etc.), allowing steam accumulation zones to form symmetrically on the tool. The resulting energy "lingers" in these zones for statistically longer or deliberately shorter periods to achieve a consistent temperature pattern or even temperature distribution.

[0030] The solution proposed here enables the conversion of a state-of-the-art asymmetric cooling to a symmetric influence by targeted steering of the steam / draft gas flow.

[0031] Further features, embodiments and advantages emerge from the following presentation of embodiments with reference to the figures. Short description of the characters

[0032] In the drawings shows: Fig. 1 is a schematic representation of a fiber processing device; Fig. 2 is a schematic perspective representation of the tool bodies of a hot pressing device; Fig. 3 is a schematic plan view of one of the tool bodies of Fig. 2 ; Fig. 4 is a schematic representation of a tool body with a device for supplying a gas stream; Fig. 5 is a schematic representation of the temperature distribution in a tool body; and Fig. 6 is a schematic representation of a tool body. Detailed description of implementation examples

[0033] 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 shown. 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."

[0034] Fig. 1shows a schematic representation of a fiber processing device 1000 for producing three-dimensional molded parts 3000 from a fiber-containing material. In the illustrated embodiment, the fiber-containing material for producing molded parts 3000 is processed in a pulp tank 200 of the fiber processing device 1000. For this purpose, water and fiber materials, as well as any additives, can be introduced into a pulp tank 200 via a liquid supply, and the pulp can be processed in the pulp tank 200 by mixing the individual components with heat input and aids such as a stirrer.

[0035] Pulp is an aqueous solution containing fibers. The fiber content of the aqueous solution can range from 0.1 to 10 wt.%. It may also contain additives and supplements, such as starch, chemical additives, wax, etc. The fibers can be, for example, natural fibers, such as cellulose fibers, or fibers from a fibrous source material (e.g., waste paper). A fiber processing plant offers the possibility of processing pulp in large quantities and making it available to several fiber processing facilities.

[0036] The fiber processing device 1000 can be used to produce, for example, biodegradable molded parts 3000, such as cups, capsules, bowls, plates, and other molded and / or packaging parts (e.g., as holder / support structures for electronic devices). Since the starting material for these products is a fibrous pulp with natural fibers, the products produced in this way can themselves be used as starting material for the production of similar products after use or can be composted, as they are generally completely decomposable and do not contain any harmful, environmentally hazardous substances.

[0037] The Fig. 1The fiber processing device 1000 shown has a frame 100, which can be surrounded by a casing. The supply units 300 of the fiber processing device 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 (e.g., comprising a vacuum tank and / or fan), 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 exist. The data connection can, for example,between the control unit 310 and a central controller for multiple fiber processing devices 1000, to a fiber processing system, to a service center, and / or other devices. A bidirectional data connection can also be used to control the fiber processing device 1000 via a mobile device, such as a smartphone, tablet computer, or the like.

[0038] The control unit 310 is in bidirectional communication 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 fiber processing device 1000 for selectable components or the entire fiber processing device 1000. The display can be designed as a touch display, so that settings can be made manually by an operator of the fiber processing device 1000. Additionally or alternatively, further input means, 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 fiber processing device 1000.

[0039] The fiber processing device 1000 comprises a robot 500. The robot 500 is designed as a so-called 6-axis robot and is thus capable of picking up parts, rotating them, and moving them in all spatial directions within its operating radius. Instead of the robot 500 shown in the figures, other handling devices can also be provided, which are designed to pick up products (preforms, molded parts) and twist them 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 fiber processing device 1000 can deviate from the illustrated embodiment.

[0040] A suction tool 520 is arranged on the robot 500. In the illustrated embodiment, the suction tool 520 has cavities formed as negatives of the three-dimensional molded parts 3000 to be formed, serving as suction cavities. The cavities can, for example, have a mesh-like surface to which fibers from the pulp adhere during suction. Behind the mesh-like surfaces, the cavities are connected to a suction device via channels in the suction tool 520. The suction device can, for example, be implemented 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 cavities are at least partially located in the aqueous fiber solution, the pulp. A vacuum or negative pressure for sucking fibers when the suction tool 520 is located in the pulp basin 200 and the pulp can be provided via the suction device 320.For this purpose, the fiber processing device 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 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" fibers, for which purpose the suction device 320 is switched to a different operating mode depending on its design.

[0041] During the production of molded parts 3000 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 cavities so that fibers are sucked out of the pulp and, for example, adhere to the network of cavities of the suction tool 520.

[0042] The robot 500 then lifts the suction tool 520 from the pulp tank 200 and moves it, along with the fibers adhering to the cavities, which still have a relatively high moisture content of, for example, over 80% by weight of water, to a pre-pressing station 400 of the fiber processing device 1000, wherein the negative pressure in the cavities is maintained for transfer. The pre-pressing station 400 has a pre-pressing tool with pre-pressing molds. The pre-pressing molds can, for example, be designed as positives of the molded parts 3000 to be produced and can have a size appropriate to the shape of the molded parts 3000 to accommodate the fibers adhering in the cavities.

[0043] During the production of molded parts 3000, the suction tool 520, with the fibers adhering to the cavities, is moved to the pre-pressing station 400 so that the fibers are pressed into the cavities. The fibers are pressed together in the cavities, creating a stronger bond between the fibers. Furthermore, the moisture content of the preforms formed from the suction-adhered 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 molds can be used to press out water. These molds are inflated, for example, using compressed air (process air), thereby pressing the fibers against the wall of a cavity of another suction tool part. This "inflating" process both presses out water and reduces the thickness of the suction-adhered fiber layer.

[0044] During pre-pressing, liquid or pulp can be sucked out and returned via the suction tool 520 and / or via further openings in pre-press molds or tool parts (cavities).

[0045] 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. For this purpose, the negative pressure is maintained at the suction tool 520 so that the preforms remain in the cavities. The preforms are transferred via the suction tool 520 to a lower tool body 620, which can be moved along the production line from the hot-pressing device 610. When the lower tool body 620 is in its extended position, the suction tool 520 is moved to the lower tool body 620 so that the preforms can be placed on molding devices 624 of the lower tool body 620.Subsequently, overpressure is generated via the openings in the suction tool 520, so that the preforms are actively deposited from the cavities, or the suction is terminated, so that the preforms remain on the molding devices 624 of the lower tool body 620 due to gravity. By providing overpressure at the openings of the cavities, pre-pressed preforms that are resting / adhering in the cavities can be released and dispensed.

[0046] 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 3000 from fibrous material.

[0047] After the preforms have been transferred, the lower tool body 620 moves into the hot-pressing station 600. In the hot-pressing station 600, the preforms are pressed into finished molded parts 3000 under heat input and high pressure, for which purpose an upper tool body 630 is brought onto the lower tool body 620 via a press.

[0048] The upper tool body 630 has cavities (molding devices) corresponding to the molding devices 624. The molding devices 624 can be connected to the tool bodies 620, 630 (e.g., screwed) or installed integrally. In the illustrated embodiments, the molding devices 624 are screwed to the tool bodies 620, 630.

[0049] After the hot-pressing process, the lower tool body 620 and the upper tool body 630 are moved away from one another, and the upper tool body 630 is moved along the fiber processing device 1000 in the production direction. After hot-pressing, the finished molded parts 3000 are sucked in via the upper tool body 630 and thus remain within the cavities. Thus, the finished molded parts 3000 are removed from the hot-pressing station 600 and, after being moved, are deposited on a conveyor belt of a conveyor device 800 via the upper tool body 630. After depositing, the suction via the upper tool body 630 is terminated, and the molded parts 3000 remain on the conveyor belt. The upper tool body 630 moves back to the hot-pressing station 600, and another hot-pressing process can be performed.Alternatively, the lower tool body 620 can be moved in an opposite direction before extending to receive the preforms, in order to remove the finished products / molded parts 3000 from the hot-pressing device for further transport. Furthermore, a hot-pressing device 610 can also be loaded with preforms from other locations, whereby no lateral movement of the tool bodies 620, 630 is necessary.

[0050] In the exemplary embodiment, the fiber processing device 1000 further comprises a conveyor device 800 with a conveyor belt. The finished molded parts 3000 made of fiber-containing material can be placed on the conveyor belt after the final molding and hot-pressing in the hot-pressing station 600 and removed from the fiber processing device 1000. In further embodiments, after the molded parts 3000 have been placed on the conveyor belt of the conveyor device 800, further processing can take place, such as filling and / or stacking the finished products. Stacking can be performed, for example, by an additional robot or another device.

[0051] The fiber processing device 1000 from Fig. 1shows a possible embodiment. A fiber processing device according to the technical teaching described herein can also have only one forming station with an exchangeable tool, for example a suction tool 520 or a hot-pressing tool, in which fiber-containing material can be processed, wherein various tools for producing different three-dimensional molded parts 3000 can be accommodated in the at least one forming station. The further for the fiber processing device 1000 of Fig. 1 The stations and devices shown are not absolutely necessary for the implementation of the technical teaching.

[0052] The tool bodies 620, 630 are heated by heating elements and thus brought to the required temperature. During hot pressing, the water contained in the relatively moist preforms evaporates. This hot steam is discharged via openings and channels in the molding devices 624. For this purpose, the tool bodies 620, 630 have corresponding channels that are connected to the openings. Furthermore, the tool bodies 620, 630 have secondary channels 622 (first channels) that run through the tool bodies 620, 630 and are connected to the openings and channels in the molding devices 624. A first group of parallel secondary channels 622 runs orthogonally to a second group of parallel secondary channels 622, wherein the secondary channels 622 of the first group and the second group intersect and are connected to one another at the interfaces.

[0053] Fig. 2shows a schematic perspective view of tool bodies 620, 630 of a hot-pressing device 610. The hot-pressing station 610 has four mold devices 624 and corresponding cavities on the opposite tool bodies 620, 630. In Fig. 2 624 molded parts 3000 are placed on the four molding devices.

[0054] Fig. 3 shows a schematic plan view of the lower tool body 620 of Fig. 2 , wherein the molding device 624 is shown in the lower right area without a molded part 3000.

[0055] In a hot-pressing device 610, the water vapor escaping from the hot surfaces of the moist preforms during the hot-pressing process is extracted. To support the transport of vapor, a gas stream, such as process air, is introduced into the secondary channels, which is preferably heated (via additional heating devices or heat exchangers).

[0056] To achieve a uniform temperature distribution in the tool body 620, a device 640 is provided, which has a main channel 642 (second channel) surrounding the tool body 620. The main channel 642 has a larger diameter than the secondary channels 622. For example, the ratio of the main channel 642 to the secondary channel (622) diameter can be 1:0.1 - 0.8.

[0057] Fig. 4 shows a schematic representation of a tool body 620 with a device 640 for supplying a gas stream. The main channel 642 has four channel sections 660, 662, 664, 666. The flow of the process air stream introduced via the main channel 642 is determined such that an optimal flow is achieved to achieve an optimal, uniform temperature distribution. Fig. 5For example, a temperature distribution in the tool body 620 is shown, with the temperature being highest in areas 650 in particular and essentially the same in all four areas 650 and thus also in the forming devices 624. As shown in Fig. 4 As shown, the steam exits in all directions in the areas 650 and is distributed in the areas 650, the channel sections of the secondary channels which are assigned to the forming devices 624.

[0058] By forming the main duct 642, process air can be supplied and discharged in the four duct sections 660, 662, 664, 666, as shown in Fig. 4 shown schematically. In the exemplary embodiment, the steam-air mixture (saturated gas stream) is discharged via the channel section 666 of the main channel 642 and fed to further treatment (e.g., heat exchanger).

[0059] For this purpose, the process air must be introduced not only into one secondary duct 622, but into several secondary ducts 622 or all secondary ducts. Furthermore, the amount of process air for each secondary duct 622 must be determined, whereby the amount for each secondary duct 622 can vary.

[0060] At the Fig. 5 For example, with the temperature distribution shown, water vapor can linger longer in areas 650 than in the sections surrounding areas 650. Furthermore, the process air flow in the tool body 620 is adjusted to prevent excessive cooling.

[0061] The cross sections in the connection points between the main channel 642 and the secondary channels 622 are designed in such a way that the Fig. 5The temperature distribution shown is established. Controllable throttle elements (flaps, valves) can also be provided at the connection points for this purpose. These can be used to adjust the temperature during operation and / or to change the temperature when changing the tool.

[0062] By selecting and arranging cross sections in the channels (main channel 642, secondary channels 622), the flow conditions can be specifically directed to ensure uniform temperature distribution.

[0063] This achieves a uniform temperature distribution in the tool body 620, which increases the efficiency of the hot pressing process, increases process stability and improves product quality. List of reference symbols

[0064] 100Frame 200Pulp basin 300Supply units 310Control unit 320Suction device 400Pre-press station 500Robot 520Suction tool 600Hot-press station 610Hot-press device 620Lower tool body 622Sub-channel 624Molding device 630Upper tool body 640Device 642Main channel 650Area 660Channel section 662Channel section 664Channel section 666Channel section 700HMI panel 800Conveyor device 810Camera 1000Fiber processing device 3000Molded part

Claims

1. Device for supplying a gas stream to a tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, comprising first channels in a tool body of the tool in the region of molding devices for forming products and at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels, wherein the diameter of the at least one second channel is greater than the diameter of the first channels.

2. Device according to claim 1, wherein the first channels are interconnected at least in the regions of forming devices.

3. Device according to claim 1 or 2, wherein the at least one second channel surrounds all regions of forming devices of a tool body together.

4. Device according to one of claims 1 to 3, wherein connecting points between the first channels and the at least one second channel have a smaller diameter than the first channels.

5. Device according to one of claims 1 to 4, wherein the opening width of connecting points between the first channels and the at least one second channel is adjustable.

6. Device according to one of claims 1 to 5, wherein the at least one second channel is divided into channel sections, and the supply of a gas stream into the channel sections is controllable.

7. Device according to one of claims 1 to 6, wherein the supply of a gas stream into the at least one second channel and / or the first channels can be regulated by throttle elements and / or conveying devices.

8. Device according to one of claims 1 to 7, comprising at least one device for tempering a gas stream that can be fed into the at least one second channel and / or the first channels.

9. Device according to one of claims 1 to 8, wherein the first channels comprise a number of channels extending orthogonally to one another.

10. Tool for forming molded parts from a fibrous material, wherein steam generated during forming can be discharged from the molded parts pressed in the tool via channels in the tool, comprising first channels in a tool body of the tool in the region of molding devices for forming products and at least one device according to one of claims 1 to 9, wherein the at least one device has at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels.

11. A method for controlling the supply of a gas stream into a tool for forming molded parts from a fibrous material, wherein steam generated during the molding process is discharged from the molded parts pressed in the tool via channels in the tool, wherein the tool has first channels in a tool body of the tool in the region of molding devices for molding products and at least one device according to one of claims 1 to 9 is provided, wherein the at least one device has at least one second channel which is connected to the first channels and surrounds the regions in the tool body with the first channels, wherein the supply of a gas stream into the at least one second channel and / or the first channels is controllable via at least one throttle device and / or a conveying device.

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