Device for supplying a gas stream to a tool for forming molded parts, tool with such a device and method for controlling the supply of a gas stream

Abstract

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 area of ​​forming devices for forming products and at least one second channel which is connected to the first channels and surrounds the areas in the tool body with the first channels, wherein the diameter of the at least one second channel is larger than the diameter of the first channels.

Description

Technical field

[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 to a tool are described.

[0002] Fibrous materials are increasingly used to manufacture 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 both natural and synthetic fibers. Recently, there has been an increase in the use of fibrous materials that contain natural fibers or are made from fibers derived from renewable resources or recycled paper. The natural fibers are mixed with water and, if necessary, other additives, such as starch, in a 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 manufacture packaging, etc., and the product properties of the product being manufactured. background

[0003] The production of fiber-containing products from pulp generally takes place in several work steps. For this purpose, a fiber processing plant has several stations or...

[0004] Forming stations are used. In a forming station, for example, fibers can be drawn into a cavity of a suction tool, thereby forming a preform. For this purpose, the pulp is provided in a pulp reservoir, 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 through openings in the suction cavity, which are connected to a corresponding suction device, causing fibers from the pulp to accumulate on the surface of the suction cavity. The drawn-in fibers, or a preform, can then be transferred via the suction tool into a pre-compression tool, where the preform is pre-compressed. For this, for example, elastic molds can be used, which are inflated for compression and thereby exert pressure on the preforms.During this pre-pressing process, the fibers in the preform are compressed and the water content of the preform is reduced. Alternatively, preforms can be provided by scooping, whereby a scooping tool is immersed in the pulp and, as it is raised, fibers are deposited on the molded parts of the scooping tool.

[0005] Afterwards, preforms are pressed into finished molded parts using a hot pressing device. Preforms are placed in a hot pressing tool, which typically has a lower and an upper mold half that are heated. Within the hot pressing tool, the preforms are pressed between mold components 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 afterward. The steam generated during hot pressing is extracted through openings in the cavities and channels in the hot pressing tool.

[0006] A manufacturing process and a fiber processing facility for this purpose are known, for example, from DE 10 2019 127 562 A1.

[0007] To remove hot steam, it has been proposed to provide an additional gas flow, which is introduced into the hot pressing tool and mixes with the steam extracted from the cavities. However, this flow causes asymmetrical cooling of the hot pressing tool and the associated forming components. This asymmetrical cooling significantly impacts the hot pressing forming process, as it also severely affects the heating of the forming components. Consequently, the cycle time increases because the heating time for the cavities that take the longest to return to the required temperature determines the overall cycle time. Task

[0008] In contrast, the task is to provide a solution that ensures a uniform temperature distribution in a ventilated tool. Furthermore, another objective is to overcome the problems of the prior art and provide an alternative to known tools. Solution

[0009] The aforementioned problem is solved 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 area of ​​forming devices for forming molded parts and at least one second channel which is connected to the first channels and surrounds the areas in the tool body with the first channels, wherein the diameter of the at least one second channel is larger than the diameter of the first channels.

[0010] The system achieves targeted control and division of the guided gas or steam flow, generating a main gas flow and secondary gas or steam flows within and around the tool. The first channels run within the tool body and are connected to the forming elements located above and below it via openings and, if necessary, further channels. These first channels extend within the tool body parallel to the forming surface on which forming elements are located or planned. Such a tool body has areas located above and below the forming elements that are associated with them. During hot pressing, steam is extracted into these areas first.When an additional gas flow is supplied for aeration, the aeration process depends on the position of the supply point, the design of the first channels, the number and size of the mold assembly, and the shape of the mold body. Since the supply is typically located at one side / point in the prior art, the supply is uneven, resulting in varying degrees of water vapor being carried away from the mold body in the first channels. Some areas are aerated quickly and thus tend to cool down rapidly, while in other areas the hot water vapor remains for a relatively long time, preventing any cooling. The additional gas flow can be further aerated, for example, by means of at least one second channel, which preferably surrounds the mold or mold body in the plane of the first channels or parallel to them.Ventilation can be introduced on two or three sides of a tool block, thus ensuring more uniform airflow. Furthermore, if the residence time of water vapor extracted from the cavities or molding devices, as well as the flow rate, is determined beforehand, the supply of a gas flow from the second channel to individual channels can be specifically controlled to optimize the overall airflow for a uniform temperature distribution.

[0011] Advantageously, the at least one second channel is designed such that it has a larger cross-section than the first channels, thereby regulating the flow through the first channels via a gas flow supplied through the at least one second channel in a first step.

[0012] The device thus enables the subdivision of main / secondary gas flows or steam flows by adjusting and selecting flow cross-sections and by narrowing or widening them. Gas flows include both gas mixtures (e.g., air) and gases.

[0013] Furthermore, 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 locations without a significant pressure increase, and the reduced flow rate at these locations minimizes the (unnecessary energy removal).

[0014] It is of particular importance that the steam from the molding devices or cavities can escape into the periphery (tool body, base, basic structure, pipe system, hose system) without pressure or almost without pressure, whereby the steam flow is superimposed on an existing air or gas flow.

[0015] This ensures a uniform temperature distribution within a tool, such as a hot pressing tool for manufacturing molded parts from a fiber-reinforced material. This leads to increased efficiency of the hot pressing process, improved process stability, and enhanced product quality of the hot-pressed parts. Furthermore, the design of the cross-sections for the first channels and the at least one second channel can take into account the local cooling of the molding components and / or the tool body. This cooling occurs when water escaping from preforms evaporates due to the thermal energy extracted from the tool or molding components. This allows, for example, the tool body to be kept at a substantially constant temperature during the hot pressing process, particularly over multiple cycles. This further enhances the aforementioned advantages.

[0016] In further embodiments, the first channels can be interconnected at least in the areas of forming equipment, so that the ventilation or flow through for targeted steam removal is improved.

[0017] In further embodiments, the at least one second channel can surround all areas of the forming elements of a tool body. Preferably, the at least one second channel extends around a tool body, thus surrounding 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 common supply of an additional gas flow but also for the removal of a saturated gas flow, wherein the saturated gas flow has absorbed water vapor from the areas of the forming elements.

[0018] In further embodiments, the connection points between the first channels and at least one second channel can have a smaller diameter than the first channels. In this case, the connection points act as throttling elements and significantly influence the amount of gas flowing into the respective first channel. The connection points can be designed differently for the first channels to achieve the necessary flow rate for a uniform temperature distribution.

[0019] In further embodiments, the opening width of the connection points between the first channels and at least one second channel can be adjustable to allow for adjustments, for example, when changing tools to produce different molded parts, where the molding units connected to a tool body are exchanged. During such a tool change, the areas of the molding units can change. Furthermore, other molding unit-specific characteristics influence the amount of steam entering the first channels. Thus, the adjustable opening width allows for both tool changes and adjustments during tool operation, for example, if changes are detected in the finished molded parts and / or in the discharged saturated gas stream. This can be achieved, for example, via a control system and appropriate detection devices (camera, sensors, etc.).A change can be detected. The control system can then, for example, adjust the throttle valves to change their opening width. For this purpose, a camera can be used to capture the surface of the molded parts after hot pressing. Moist areas can thus be visually detected. The position of each molded part allows a direct inference to be made about the corresponding first channels or the respective area of ​​the molding unit, and the corresponding throttle valves of these channels can be controlled. Machine learning can also be integrated, for example, by performing a test run and obtaining reference data for the control system.

[0020] In further embodiments, the at least one second channel can be subdivided into channel sections, and the supply of gas flow to these channel sections can be regulated. This allows for further control of the amount of gas flow primarily available and supplied to the first channels, in order to achieve a uniform temperature distribution within the tool.

[0021] In further embodiments, the supply of a gas flow into at least one second channel and / or the first channels can be regulated by throttling elements and / or conveying devices. Throttling elements can be, for example, valves or throttle valves.

[0022] Conveying devices can be, for example, pumps or fans that are integrated into and / or connected to the second channel. In further designs, the flow through the tool and the supply of an additional gas flow can also be controlled by a suction or negative pressure prevailing at a discharge line for saturated gas flow. Conveying devices can be used for this purpose.

[0023] In further embodiments, the device can include at least one device for tempering a gas stream that can be fed into 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 because warmer air can become more saturated with water, thus allowing more steam to be discharged.

[0024] In further embodiments, the first channels can have a number of orthogonally arranged channels. Ideally, at least one second channel has large cross-sections around the tool and cross-sectional constrictions in transverse and longitudinal channels (first channels) within a tool body.

[0025] Such a device can, for example, be attached to a tool with existing initial channels for flow through it, or be provided as an integral component of a tool.

[0026] The aforementioned problem is also solved 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 area of ​​forming devices for forming molded parts and at least one device according to one of the preceding embodiments, wherein the at least one device has at least a second channel which is connected to the first channels and surrounds the areas in the tool body with the first channels.

[0027] A main gas flow integrated into 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, through gas flow does not cool a hot tool body asymmetrically despite uniform ventilation, thus creating a uniform temperature pattern on the cavities or forming devices.

[0028] The aforementioned problem is further solved 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 forming 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 area of ​​forming devices for forming molded parts and at least one device according to one of the preceding embodiments is provided, wherein the at least one device has at least a second channel which is connected to the first channels and surrounds the areas 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 can be controlled via at least one throttling device and / or a conveying device.

[0029] The supplied gas / air or steam flow is directed into technically favorable paths, since main and secondary channels are provided in a tool body of the tool, onto which the resulting steam can "spring" without pressure and according to the amount produced.

[0030] In addition, the steam flow is selectively influenced and directed alongside main channels using secondary channels with cross-sectional constrictions and expansions (bore diameter, blind plugs, etc.), so that symmetrical steam accumulation zones can also form on the tool. In these zones, the generated energy "remains" statistically longer or selectively for a shorter time to achieve a uniform temperature pattern or even temperature distribution.

[0031] The solution proposed herein enables the transformation of asymmetric cooling from the prior art by targeted control of the steam / passage gas flow to a symmetric influence.

[0032] Further features, designs and advantages will become apparent from the following presentation of exemplary embodiments with reference to the figures. Brief description of the characters

[0033] The drawings show: Fig. 1 a schematic representation of a fiber processing facility; Fig. 2 a schematic perspective representation of the tool bodies of a hot pressing device; Fig. 3 a schematic top view of one of the tool bodies of Fig. 2; Fig. 4 a schematic representation of a tool body with a device for supplying a gas stream; Fig. 5 a schematic representation of the temperature distribution in a tool body; and Fig. 6 a schematic representation of a tool body. Detailed description of implementation examples

[0034] The following are exemplary embodiments of the technical teaching described herein, with reference to the figures. The same reference numerals are used in the figure descriptions for identical components, parts, and processes. Components, parts, and processes that are immaterial to the technical teaching disclosed herein or that are obvious to a person skilled in the art are not explicitly shown. Features given in the singular are also included in the plural unless explicitly stated otherwise. This applies in particular to terms such as "a" or "an".

[0035] Fig. Figure 1 shows a schematic representation of a fiber processing device 1000 for the production of three-dimensional molded parts 3000 from a fiber-containing material. In the illustrated embodiment, the fiber-containing material for the production of molded parts 3000 is prepared in a pulp tank 200 of the fiber processing device 1000. For this purpose, water and fibers, as well as any additives, can be introduced into a pulp tank 200 via a liquid supply, and the pulp is prepared in the pulp tank 200 by mixing the individual components with the input of heat and auxiliary equipment, such as a stirrer.

[0036] Pulp is defined as an aqueous solution containing fibers, with the fiber content ranging from 0.1 to 10 wt%. It may also contain additives such as starch, chemical additives, wax, etc. The fibers can be, for example, natural fibers like cellulose fibers or fibers derived from a fibrous source material (e.g., recycled paper). A fiber processing plant offers the capability to process pulp in large quantities and supply it to multiple fiber processing units.

[0037] The fiber processing unit 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 holders / support structures for electronic devices). Since the starting material for these products is a fiber-containing pulp with natural fibers, the products manufactured in this way can themselves serve as a starting material for the production of such products after use, or can be composted, because they are generally completely decomposable and do not contain any harmful or environmentally hazardous substances.

[0038] The in Fig. The fiber processing unit 1000 shown has a frame 100, which may be enclosed by a casing. The supply units 300 of the fiber processing unit 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 unit 320 (e.g., comprising a vacuum tank and / or fan), piping 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. A data connection via a fiber optic cable may also exist instead of a wired data connection. The data connection may, for example,A connection exists between the control unit 310 and a central control system for multiple fiber processing units 1000, a fiber preparation plant, a service center, and / or other facilities. The fiber processing unit 1000 can also be controlled via a mobile device, such as a smartphone, tablet computer, or similar device, using a bidirectional data connection.

[0039] The control unit 310 communicates bidirectionally with an HMI panel 700 via a bus system or data connection. The HMI (Human-Machine Interface) panel 700 features a display that shows operating data and statuses of the fiber processing unit 1000 for selectable components or the entire fiber processing unit 1000. The display can be a touchscreen, allowing an operator of the fiber processing unit 1000 to manually adjust settings. Additionally or alternatively, the HMI panel 700 can be equipped with other input devices, such as a keyboard, joystick, or keypad, for operator input. These allow settings to be changed and the operation of the fiber processing unit 1000 to be influenced.

[0040] The fiber processing unit 1000 includes a robot 500. The robot 500 is designed as a so-called 6-axis robot and is therefore 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, designed to pick up and twist or rotate products (preforms, molded parts) and move them in various spatial directions. Furthermore, such a handling device can also be configured differently, in which case the arrangement of the corresponding stations of the fiber processing unit 1000 may differ from the illustrated embodiment.

[0041] 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 unit 320. Pulp can be drawn in via the suction device when the suction tool 520 is positioned within the pulp basin 200 such that the cavities are at least partially immersed in the aqueous fiber solution, i.e., the pulp. A vacuum or negative pressure for suctioning 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 unit 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 perform a "blowing out" operation, for which the suction device 320 is switched to a different operating mode according to its design.

[0042] In 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 the cavities of the suction tool 520.

[0043] The robot 500 then lifts the suction tool 520 from the pulp basin 200 and moves it, along with the fibers adhering to the cavities (which still have a relatively high moisture content, e.g., over 80 wt% water), to a pre-compression station 400 of the fiber processing unit 1000, maintaining negative pressure in the cavities for the transfer. The pre-compression station 400 has a pre-compression tool with pre-compression molds. The pre-compression molds can, for example, be designed as positives of the molded parts 3000 to be produced and have a corresponding size, relative to the shape of the molded parts 3000, to accommodate the fibers adhering to the cavities.

[0044] In 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 in such a way that the fibers are pressed into the cavities. This compresses the fibers together within the cavities, creating a stronger bond between them. Furthermore, the moisture content of the preforms formed from the suctioned fibers is reduced, so that the preforms produced after pre-pressing have a moisture content of, for example, only 60 wt.%. Flexible pre-pressing molds can be used to expel water; these are inflated, for example, with compressed air (process air), pressing the fibers against the wall of a cavity in another suction tool component. This inflation process both expels water and reduces the thickness of the suctioned fiber layer.

[0045] During pre-pressing, liquid or pulp can be extracted and returned via the suction tool 520 and / or via other openings in pre-pressing molds or tool parts (cavities).

[0046] After pre-pressing in the pre-pressing station 400, the preforms produced are moved by the robot 500 via the suction tool 520 to a hot pressing station 600. For this purpose, the vacuum is maintained at the suction tool 520 to keep the preforms 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 unit 610. When the lower tool body 620 is in its extended position, the suction tool 520 is moved towards the lower tool body 620 so that the preforms can be placed onto the forming devices 624 of the lower tool body 620.Subsequently, overpressure is generated via the openings in the suction tool 520, causing the preforms to be actively deposited from the cavities, or the suction is terminated, leaving the preforms to remain on the forming elements 624 of the lower tool body 620 due to gravity. By providing overpressure at the cavity openings, pre-pressed preforms that are in contact with / adhere to the cavities can be released and dispensed.

[0047] Afterwards, the suction tool 520 is moved away via the robot 500 and the suction tool 520 is immersed in the pulp basin 200 to suck up further fibers for the production of molded parts 3000 from fiber-containing material.

[0048] After the preforms are transferred to the hot pressing station 600, the lower tool body 620 moves. In the hot pressing station 600, the preforms are pressed into finished molded parts 3000 under heat and high pressure, for which purpose an upper tool body 630 is brought onto the lower tool body 620 via a press.

[0049] The upper tool body 630 has cavities (forming devices) corresponding to the forming devices 624. The forming devices 624 can be connected to the tool bodies 620, 630 (e.g., screwed on) or integrally integrated. In the illustrated embodiments, the forming devices 624 are screwed to the tool bodies 620, 630.

[0050] After the hot pressing process, the lower tool body 620 and the upper tool body 630 are moved away from each other, and the upper tool body 630 is moved along the fiber processing unit 1000 in the production direction. Following hot pressing, the manufactured parts 3000 are drawn in by the upper tool body 630 and thus remain within the cavities. The manufactured parts 3000 are then removed from the hot pressing station 600 and placed on a conveyor belt of a conveying unit 800 via the upper tool body 630. After placement, the suction action via the upper tool body 630 is terminated, and the parts 3000 remain on the conveyor belt. The upper tool body 630 returns to the hot pressing station 600, and another hot pressing process can be carried out.Alternatively, the lower tool body 620 can be moved in the opposite direction before extending to receive the preforms, in order to remove the manufactured products / molded parts 3000 from the hot pressing device for further transport. Furthermore, a hot pressing device 610 can also be loaded with preforms in another way, whereby no lateral movement of tool bodies 620, 630 is required.

[0051] In this embodiment, the fiber processing unit 1000 further comprises a conveyor unit 800 with a conveyor belt. The manufactured molded parts 3000 made of fiber-containing material can be placed on the conveyor belt after final forming and hot pressing in the hot pressing station 600 and discharged from the fiber processing unit 1000. In other embodiments, further processing can take place after the molded parts 3000 are placed on the conveyor belt of the conveyor unit 800, such as filling and / or stacking the manufactured products. Stacking can be carried out, for example, by an additional robot or other device.

[0052] The fiber processing unit 1000 made of Fig. Figure 1 shows a possible embodiment. A fiber processing device according to the technical teaching described herein can also comprise only one forming station with an interchangeable tool, e.g., a suction tool 520 or a hot press 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 components for the fiber processing device 1000 of Fig. The stations and devices shown in Figure 1 are not absolutely necessary for the implementation of the technical teaching.

[0053] 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, with the secondary channels 622 of the first and second groups intersecting and being connected to each other at the intersections.

[0054] Fig. Figure 2 shows a schematic perspective view of tool bodies 620, 630 of a hot pressing device 610. The hot pressing station 610 has four forming devices 624 and corresponding cavities on the opposing tool bodies 620, 630. Fig. 2 are mounted on the four molding devices, 624 molded parts 3000.

[0055] Fig. Figure 3 shows a schematic top view of the lower tool body 620 of Fig. 2, wherein the forming device 624 is shown in the lower right area without a forming part 3000.

[0056] In a hot pressing device 610, the water vapor escaping from the moist preforms at the hot surfaces during the pressing process is extracted. To assist the transport of steam, a gas stream, e.g., process air, is introduced into the secondary channels, which is preferably heated (via additional heating devices or heat exchangers).

[0057] To achieve a uniform temperature distribution within 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 main channel 642 to secondary channel (622) diameter can be 1:0.1 - 0.8.

[0058] Fig. Figure 4 shows a schematic representation of a tool body 620 with a device 640 for supplying a gas flow. 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 optimal flow is achieved to ensure an optimal, uniform temperature distribution. Fig. Figure 5 shows, for example, a temperature distribution in the tool body 620, where the temperature is highest in areas 650 and is essentially the same in all four areas 650, and thus also in the forming devices 624. As in Fig. As shown in Figure 4, the steam escapes 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.

[0059] The design of the main channel 642 allows process air to be both supplied and discharged in the four channel sections 660, 662, 664, 666, as shown in Fig. Figure 4 shows schematic representation. In this embodiment, the vapor-air mixture (saturated gas stream) is discharged via channel section 666 of the main channel 642 and fed to further treatment (e.g., heat exchanger).

[0060] For this purpose, it is necessary to introduce the process air not only into one secondary channel 622, but into several secondary channels 622 or all secondary channels. Furthermore, the quantity of process air for each secondary channel 622 must be determined, and this quantity can vary for each secondary channel 622.

[0061] At the in Fig. In the temperature distribution shown in Figure 5, water vapor can, for example, remain 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.

[0062] The cross-sections at the junctions between the main channel 642 and the secondary channels 622 are designed such that the Fig.The temperature distribution shown in section 5 is set. Controllable throttling elements (flaps, valves) can also be provided at the connection points for this purpose. This allows for adjustments during operation and / or changes when changing tools.

[0063] By selecting and arranging cross-sections in the channels (main channel 642, secondary channels 622), the flow conditions can be specifically directed to achieve a uniform temperature distribution.

[0064] This ensures a uniform temperature distribution in the tool body 620, thereby increasing the efficiency of the hot pressing process, increasing process stability and product quality. Reference symbol list 100 frames 200 pulp basins 300 supply units 310 Control unit 320 Intake system 400 pre-pressing station 500 robots 520 suction tool 600 Hot Press Station 610 Hot pressing device 620 lower tool body 622 Secondary channel 624 Molding unit 630 upper tool body 640 facility 642 Main Channel 650 area 660 Canal section 662 Canal section 664 Canal section 666 Canal section 700 HMI panel 800 funding facility 810 camera 1000 fiber processing equipment 3000 molded parts

Claims

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 area of ​​forming devices for forming products and at least one second channel which is connected to the first channels and surrounds the areas in the tool body with the first channels, wherein the diameter of the at least one second channel is larger than the diameter of the first channels. Device according to claim 1, wherein the first channels are interconnected at least in the areas of forming devices. Device according to claim 1 or 2, wherein the at least one second channel jointly surrounds all areas of forming devices of a tool body. Device according to one of claims 1 to 3, wherein the connection points between the first channels and the at least one second channel have a smaller diameter than the first channels. Device according to one of claims 1 to 4, wherein the opening width of connection points between the first channels and the at least one second channel is adjustable. 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 flow into the channel sections is controllable. Device according to one of claims 1 to 6, wherein the supply of a gas flow into the at least one second channel and / or the first channels is controllable by throttling elements and / or conveying devices. Device according to one of claims 1 to 7, comprising at least one device for tempering a gas stream that can be supplied to the at least one second channel and / or the first channels. Device according to any one of claims 1 to 8, wherein the first channels comprise a number of orthogonally extending channels. Tool for forming parts from a fibrous material, wherein steam generated during forming can be discharged from the parts pressed in the tool via channels in the tool, comprising first channels in a tool body of the tool in the area of ​​forming 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 a second channel which is connected to the first channels and surrounds the areas in the tool body with the first channels. Method for controlling the supply of a gas flow into a tool for forming molded parts from a fibrous material, wherein steam generated during forming 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 area of ​​forming devices for forming 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 areas 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 throttling device and / or a conveying device.

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