METHOD AND DEVICE FOR PRODUCE A FIBER MOLDED BODY

Description

[0001] The invention relates to a method for producing a fiber molded body and a device for producing a fiber molded body.

[0002] Fiber molded bodies are used for various purposes, particularly as transport packaging and for protecting sensitive goods. For example, fiber molded bodies serve as an alternative to plastic trays, as molded inserts in packaging, and as food packaging.

[0003] It is known to produce fiber-based molded parts using the fiber casting process. In this process, a mold with a porous wall is immersed in a pulp, also known as a fiber slurry. A pulp typically contains at least water and fibers, which are drawn into the mold. The fibers usually consist of cellulose. This suction is achieved through pores or openings in the porous wall of the mold, which are smaller than the fibers. Thus, only the water from the pulp is drawn out through the mold wall, while the fibers adhere to the mold wall. The fiber content is increased and compacted on the mold wall, forming a fiber-based molded part. After demolding, the fiber-based molded part is further increased by subsequent drying, which solidifies the fiber-based molded part.

[0004] The fiber casting process allows for the production of fiber-shaped bodies with complex contours using a suction mold. However, drying the wet fiber-shaped body is very time-consuming and energy-intensive because the fiber-shaped body deposited on the mold wall has a very high water content. The water must be almost completely evaporated before the formed fiber-shaped body can be used. Both the water consumption and the energy consumption for the fiber casting process are quite high.

[0005] Alternatives to the fiber casting process are known in the prior art. For example, publications SE 541 995 C2 and SE1750313 A disclose a process for producing a non-flat fiber-based molded body, referred to as a cellulose product. The process comprises the dry forming of cellulose fibers into a flat cellulose web in a dry forming unit. For the dry forming of the cellulose web, the dry forming unit includes a cutting unit for separating the cellulose fibers, a forming screen for forming the web from the cellulose fibers, and a compaction unit for compacting the cellulose fibers. Water and one or more additives are added to the cellulose fibers and / or the cellulose blank. The cellulose product is formed by heating the cellulose web to a forming temperature in the range of 140°C to 200°C and pressing the cellulose blank with a forming pressure of at least 4 MPa. The additive or...The additives are sprinkled in solid form onto the cellulose fibers and / or the cellulose web. In this process, the production of the non-flat fiber-shaped body therefore occurs indirectly via a flat cellulose web.

[0006] A process for producing a molded fiber body, also known as a shaped product, is also known from European patent EP 3 889 347 A1. This process comprises mixing fibers with a composite material to form a mixture, wherein the composite material contains cellulose fibers and 30% to 50% starch at least partially fused with the cellulose fibers. The mixture is moistened at least once, and the moistened mixture is formed into the shaped product by pressurization and heating. In particular, the moistened mixture is deposited on a net-like conveyor belt and concentrated there. The conveyor belt feeds the fiber web to a forming device in which the fiber web is pressed. Thus, in this process as well, the molded fiber body is produced via a flat fiber web.

[0007] Producing a fiber web, which is then formed into the shape of the fiber-based component to be manufactured, is time-consuming and energy-intensive. Furthermore, the fiber web can thin and / or tear during pressing into the intended shape because pressing involves a high degree of deformation of the fiber web.

[0008] The patent applications US 5 376 327 A and DE 10 2015 200 275 A1 describe methods for manufacturing fiber-shaped bodies using carbon fibers and plastic fibers.

[0009] The invention is based on the objective of providing a technically simple method and a technically simple device that enable the rapid and energy-efficient production of biodegradable fiber molded bodies with particularly low waste.

[0010] According to the invention, this problem is solved by a method having the features of claim 1 and by a device having the features of claim 10. Advantageous embodiments are described in the dependent claims.

[0011] The process described here for manufacturing a fiber-shaped body comprises the following process steps: Arranging a suction mold with a porous wall, the contour of which corresponds to the contour of the fiber body to be produced, in a chamber; introducing a fiber material-air mixture into the chamber, wherein the fiber material is dispersed in the air in the form of solid particles; drawing in the fiber material-air mixture through the porous wall of the suction mold and compacting the fiber material to form the fiber body against the porous wall; removing the fiber body from the suction mold and from the chamber, wherein the fiber material consists mainly of cellulose fibers and wherein the fiber material is moist and / or water in the form of droplets or water vapor is added to the fiber material-air mixture.

[0012] The invention is therefore based on the idea of ​​depositing the starting materials from which the fiber-shaped body is formed (i.e., in particular fiber material) directly from the air onto a porous wall of a suction mold and compacting them there, so that the fiber-shaped body has the geometry (contour) to be produced, or at least substantially the geometry (contour), immediately after the depositing and compaction of the starting materials.

[0013] The fiber-based molded body is produced from biodegradable and preferably compostable raw materials. Depending on the requirements for the optical properties of the molded fiber body, the fiber material is then primarily composed of cellulose, other recycled fibers, and / or virgin fibers, all of which are biodegradable and preferably compostable. This ensures that the molded fiber body itself is also biodegradable and preferably compostable. The fibers can consist mainly of cellulose fibers, as are commonly used in the conventional pulp molding process for manufacturing molded fiber bodies. However, other fibers, such as hemp fibers, can also be used. This allows for the production of molded fiber bodies with high strength and good mechanical properties. Depending on the intended use, the fibers from different raw materials can also be blended.

[0014] The fiber material can be introduced into the fiber-air mixture in a slightly moistened state so that it sets during compaction to form the desired shape. However, the moisture content of the fiber material can cause problems when the fibers are agitated in the air. Therefore, water in the form of droplets or steam can be added to the agitated fiber-air mixture to achieve the optimal moisture level for fiber set during compaction. Alternatively, completely dry fibers can be agitated with air, and the total amount of water required for set can be added to the agitated fiber-air mixture.

[0015] In some embodiments, a first fiber-air mixture can be introduced into the chamber and drawn in, so that a first layer of fiber material is formed on the porous wall of the suction mold. Subsequently, at least one further fiber-air mixture can be introduced into the chamber and drawn in, so that at least one further layer of fiber material is formed on the porous wall of the suction mold. The layers of fiber material can be compacted against the porous wall to form the fiber body, and the fiber body can then be removed from the suction mold. In other words, a first mixture can be supplied to the chamber, forming a first layer on the porous wall, and then a second layer can be supplied, forming a second layer on top of the first. This process can be repeated with a third and fourth layer, etc., as required.The fiber-air mixture used to form the different layers can vary. For example, the first fiber-air mixture can contain a different dye than the second. In this case, the outer layer of the resulting molded body will have a different color than the inner layer. Different additives can also be added to the layers. For instance, if the molded fiber body is intended for food packaging, the inner layer can be formulated so that its direct contact with the food is safe. A second layer can then be deposited on top of this inner layer, giving the molded fiber body a certain density or strength, but one that is not suitable for direct contact with food.It is also possible to create multi-layered molded bodies, in which each layer has its own function, for example, high impermeability to oxygen, high moisture resistance, or high light resistance. These different properties in the various layers can be achieved by changing the composition of the fiber-air mixture in each layer to create a layer with a specific desired property.

[0016] The suction mold can, for example, be a hollow body with a porous wall and a suction opening connected to the pores of the wall, allowing flow through it for the connection of a suction device. Alternatively, the suction mold can be designed as a body formed from a porous structure with a suction opening for connecting a suction device. In this case, a surface or at least a surface section of the body forms the porous wall of the suction mold. The contour of the porous wall corresponds to the contour of the fiber body to be produced. In other words, the surface geometry of the porous wall, or a section of the porous wall, and a surface geometry of the fiber body to be produced are complementary or substantially complementary to each other.By means of the suction device connectable to the suction mold, either a negative or positive pressure can be generated in the suction mold, and air can be drawn in or blown out through the pores of the porous wall of the suction mold. The pores in the porous wall are preferably designed such that, when the fiber material-air mixture is drawn in, the fiber material is deposited on the wall.

[0017] The porous wall of the suction mold can be formed, for example, from a metallic wire mesh. Alternatively, it can be manufactured as a solid wall with air channels using an additive manufacturing process (3D printing). In the latter case, the suction mold has greater stability.

[0018] The chamber is a predefined space in which the fiber body is formed against the porous wall of the suction mold. The chamber may have a wall with one or more openings through which the raw materials from which the fiber body is formed and / or the suction mold can be introduced. The opening in the wall can be at least partially closable, for example, by means of a door, a flap, or a sliding mechanism. The wall and the at least partially closable opening effectively prevent the fiber-air mixture from escaping into the air outside the chamber.

[0019] The suction mold can be positioned manually or automatically within the chamber. Automatic positioning allows for the automation of the process described here. This can be achieved, for example, by a suction mold carrier moved by an actuator, which can be electrically or pneumatically driven. The actuator's drive can be functionally connected to a control unit. The suction mold carrier can be designed, for instance, as a conveyor belt on which the suction mold is positioned and which moves the mold from a support position into the chamber. Alternatively, the suction mold carrier could be, for example, a robot arm.

[0020] In the process described here, multiple suction molds with identical or differently shaped porous walls can be arranged simultaneously in the chamber, allowing for the simultaneous production of multiple fiber-shaped bodies with identical or differently shaped contours. For small fiber-shaped bodies, each body can correspond to one of several sections of the porous wall of the suction mold. The simultaneous production of multiple fiber-shaped bodies enables particularly fast and energy-efficient manufacturing.

[0021] Before, during, or after the suction mold is positioned in the chamber, the fiber-air mixture is introduced. For this purpose, the fiber-air mixture can be premixed outside the chamber so that the fiber material, in the form of solid particles, is already dispersed in the air upon introduction. In this case, the fiber-air mixture can, for example, be blown into the chamber. Alternatively, the fiber material can be introduced into the chamber separately from the air. For example, the fiber material can be continuously sprinkled into the already air-filled chamber during the molding process or poured in all at once as a bulk material.

[0022] The process described here therefore forms the desired fiber-shaped body directly in a single forming step, without the need to produce an intermediate product requiring further processing. This saves considerable time. Furthermore, the formed fiber-shaped body contains very little water and therefore does not require drying.

[0023] Water is added – if at all – only to the extent necessary for the optimal setting of the components of the wall of the fiber molded body.

[0024] Regardless of the method of introducing the fiber material, it can be advantageous to actively and precisely move the air, fiber material, and / or the fiber-air mixture within the chamber to achieve homogeneous mixing of the air with the raw materials from which the fiber-based body is formed. This active and precise movement of the air, fiber material, and / or fiber-air mixture is accomplished using a device for mixing the fiber material with air, such as a propeller. The propeller swirls the air and / or the fiber-air mixture, ensuring that the fiber material is homogeneously distributed in the air. The propeller can, in particular, generate an upward flow. This creates a fluidized bed within the chamber. A fluidized bed is a bed of solid particles that are swirled up and fluidized by an upward flow of a fluid.The term "fluidized" means that the (former) bulk material exhibits fluid-like properties. Alternatively or additionally to the propeller, the device for mixing the fiber material with air can, for example, include a vibrating membrane, wherein the vibrating membrane agitates the air in front of it, the fiber material-air mixture, and / or particles of the starting materials deposited on the vibrating membrane by means of vibration.

[0025] To form the fiber mold, air is drawn in through the porous wall of the suction mold. The fiber material then adheres to the porous wall. After a specific suction time, the fiber material has compacted against the porous wall due to the intake of the fiber-air mixture, resulting in a fiber mold with the desired contour and wall thickness.

[0026] When a predetermined suction time and / or a target wall thickness of the fiber molded body is reached, the fiber molded body is removed from the suction mold and from the chamber and further processed or placed in an intermediate storage area.

[0027] In practice, the porous wall of the suction mold can have a three-dimensional contour with multiple wall sections. These wall sections define different parts of the molded part to be produced. The individual wall sections can be flat, convex, and / or concave. This allows for the formation of three-dimensional fiber molded parts with multiple surface sections on the porous wall, for example, a cup-shaped fiber molded part with a flat bottom and a cylindrical outer wall. As mentioned above, multiple fiber molded parts can also be formed on multiple surface sections of a single suction mold.

[0028] Furthermore, in practice, the fiber material can be mixed with the air in the form of fiber dust or short fibers to form a fiber-air mixture, and / or the fiber-air mixture can be an aerosol, in which the fiber material is dispersed as suspended particles in the air. Fiber dust refers to fiber material whose fibers are smaller than 500 µm and preferably smaller than 200 µm. If the fibers of the fiber material are even smaller than 20 µm and, more preferably, smaller than 10 µm, the fiber-air mixture can be an aerosol. An aerosol is a mixture of solid and / or liquid suspended particles in a gas. The fiber material then remains suspended in the air, sinks only very slowly, and, in particular, does not precipitate out within a few seconds.In an aerosol, the fiber material is regularly and homogeneously distributed in the air, allowing it to be deposited with exceptional uniformity on the porous wall of the suction mold using the process described here. Distributing the fiber material in the air requires, at most, occasional active and targeted agitation of the fiber-air mixture. This makes the formation of the fiber mold technically simple and particularly energy-efficient. Furthermore, the very small particles of fiber material from an aerosol can yield excellent properties for the resulting fiber mold. For example, the fiber mold can exhibit exceptionally high strength, high density, and / or high resistance to moisture or aggressive substances. It is also possible to process significantly longer fibers.This may require stronger agitation to ensure the fibers are evenly deposited onto the porous surface of the suction mold. A greater fiber length may be desirable, especially when processing hemp fibers.

[0029] In practice, at least one of the following additives can be added to the fiber material-air mixture: Sugars and / or starch, wax, lipids, minerals.

[0030] The additives can also be the starting materials from which the fiber-based molded body is formed. If at least one of the additives is present, the air and the starting materials—i.e., the fiber material and the at least one additive—are drawn into the suction mold, and the starting materials are deposited together on the porous wall of the suction mold. This results in a fiber-based molded body with uniformly distributed starting materials. The additives can further improve the properties of the fiber-based molded body, in particular increasing its strength, density, and / or resistance to moisture.

[0031] Water can be added in the form of droplets or as steam if the swirled fiber material is not sufficiently moist on its own. The water can condense on the surface of the fiber material and / or penetrate it. The adhesion of the water can increase the bond between the fibers deposited on the porous wall. Additionally, the water can dissolve the fiber material, further enhancing fiber adhesion. This process can result in a stable fiber composite, enabling easy and reliable removal of the fiber-shaped body from the suction mold. The strength of the finished fiber-shaped body can also be increased. However, the water content of this fiber-shaped body is significantly lower than that of a body produced from fiber pulp.

[0032] The starting materials may also contain sugars, in particular glucose, sucrose, fructose, maltose, lactose, raffinose, and stachyose, as well as starch or a mixture of at least two of the aforementioned components. Furthermore, the sugar or starch may be added, particularly in the form of solid particles. The sugar or starch can also increase the adhesion of the fibers deposited on the porous wall to one another, especially if the sugar or starch is first heated, melted, and / or dissolved by moisture, and later cooled or dried again in the fiber body. The sugar or starch then serves as a natural adhesive that bonds the fibers of the fiber body.The starch can additionally increase the hardness and abrasion resistance of the fiber molded body, because the hardness of sugar crystals is regularly greater than the hardness of most fiber materials and especially greater than the hardness of cellulose fibers.

[0033] The wax can be added in the form of solid particles or drops. In particular, carnauba wax and / or beeswax can be added.

[0034] Carnauba wax is a very hard, tropical wax with a high melting point (approx. 85-89°C). It has virtually no odor or taste and is waterproof. When dry, it is very brittle and hardens within seconds. Its hardness also makes it highly resistant to abrasion. It is approved for food packaging and has long been used as a coating to increase the shelf life of products such as mangoes and sweets. The wax may also contain beeswax or other natural waxes. Combinations of biodegradable and, ideally, compostable waxes can be used, giving the fiber-based packaging high strength and making it particularly suitable for use with packaged foods. Besides carnauba wax and beeswax, shellac and sugarcane wax are also suitable. Beeswax is a wax produced, among other places, in Europe and is less hard than carnauba wax.In a mixture with carnauba wax, beeswax helps reduce brittleness. It also has virtually no odor or taste and is approved for use in conjunction with food. Its melting point is approximately 65°C.

[0035] Lipids can also be added in the form of solid particles or droplets. Lipids are hydrophobic. Therefore, when present in the fiber molded body, they can reduce its wettability and / or increase its moisture resistance.

[0036] It should be noted that the list of additives is not exhaustive. Further additives, such as minerals or proteins, as well as colorants, can be added to the swirled fiber-air mixture. The additives to be added are selected depending on the product to be manufactured and, in particular, the desired product properties.

[0037] The size of the additives, added as solid particles or droplets, is selected such that they are homogeneously distributed in the chamber along with the fiber material, ensuring that the fiber-air mixture contains the additives in a uniform distribution. Since the additives are intended to be separated and compacted together with the fiber material, they are preferably larger than the pores in the porous wall of the suction mold. If the fiber material is mixed with air as fiber dust, the particle size of the additives may preferably correspond to the particle size of the fiber material. If the fiber-air mixture is an aerosol, the particle size of the additives may be selected to be particularly small, allowing them to remain suspended in the chamber with the fibers, thus making the entire fiber-air mixture containing the additives an aerosol.The particle size of the additives can then be, in particular, less than 20 µm and preferably less than 10 µm. The water can, in particular, be in vapor form.

[0038] In practice, the additives can be stored in separate containers. The additives can be mixed with the fiber material before the raw materials are introduced into the chamber. Alternatively, the fiber material and the additives stored in separate containers can be introduced into the chamber separately, allowing for particularly high flexibility. For example, the fiber material can be introduced as described above, and the additives can be mixed with air in the separate containers to form separate additive-air mixtures, fluidized, and then fed into the chamber as separate flows through piping. The turbulence created by these flows within the chamber homogeneously mixes the additives with the fibers and the air in the chamber to form the fiber-air mixture.

[0039] The removal of the fiber-shaped body from the suction mold can be achieved using a transfer mold. For this purpose, the transfer mold can have a wall that is essentially complementary to the porous wall of the suction mold and can be pressed with a certain pressure against the fiber-shaped body formed on the porous wall of the suction mold. This allows the fiber-shaped body to be compacted. In particular, if the porous wall of the suction mold is produced with a large wall thickness using additive manufacturing, a high strength of the formed fiber-shaped body can be achieved simply by pressing the suction mold and transfer mold together.

[0040] In practice, after removal from the suction mold, the fiber-shaped body can be transferred to a compression mold, and a counter-mold can be pressed against the fiber-shaped body arranged in the compression mold. The compression mold has a wall whose contour essentially corresponds to the contour of the porous wall of the suction mold. Preferably, the wall of the compression mold has no pores or smaller and / or fewer pores than the porous wall of the suction mold. The wall of the compression mold is preferably smooth. The counter-mold has a wall that is essentially complementary to the wall of the compression mold and is also preferably smooth. The counter-mold may also have pores.

[0041] By pressing the counter-mold against the fiber body positioned in the press mold, the fiber body can be clamped completely between the walls of the press mold and the wall of the counter-mold. The mechanical pressure then compresses and further compacts the fiber body. Due to the essentially complementary walls of the press mold and the counter-mold, the contour of the fiber body can be easily modified. In particular, small steps and / or undercuts can be incorporated. Furthermore, pressing the counter-mold against the fiber body can create a uniform wall thickness. The surfaces of the fiber body can be made exceptionally smooth by pressing, resulting in a visually high-quality fiber body. If the fiber body contains residual water, this water can be pressed out.Unlike a fiber-based molded body made from pulp, a fiber-based molded body manufactured according to the invention has a very low water content and only needs to be dried slightly - if at all.

[0042] Once the pressing action of the die and counter-die is complete, the two can be separated. The counter-die is then no longer engaged with the die. The fiber-shaped body can be removed and further processed.

[0043] In practice, it is also possible to press the fiber-shaped body in several steps. After pressing in the suction mold and the transfer mold, the fiber-shaped body can be pressed in a first press mold with a first counter-mold. If necessary, the fiber-shaped body can be transferred to a second press mold and pressed with a second counter-mold. Further pressing operations can be carried out analogously. By pressing multiple times in different press molds, the density can be successively increased and / or the surface finish of the fiber-shaped body can be successively improved.

[0044] In practice, as already mentioned, the removal and / or transfer of the fiber-shaped body from the suction mold to the compression mold can be accomplished using a transfer mold. The transfer mold has a wall that is essentially complementary to the porous wall of the suction mold. The transfer mold can be mounted on a transfer mold carrier that is driven by an actuator and functionally connected to a control unit. It can be brought into engagement with the suction mold in such a way that the wall of the transfer mold rests against the fiber-shaped body and removes it from the suction mold. The transfer mold then transfers the fiber-shaped body to an intermediate storage area or into the compression mold. The transfer mold can also be used to transfer the fiber-shaped body from one compression mold to another.In practice, the transfer form can be the previously described counter-form, which serves to press the fiber mold body against the porous wall of the suction mold and / or the compression mold.

[0045] The wall of the transfer mold can have pores, which are connected to a suction device to create either a vacuum or a positive pressure at the pores. The vacuum draws the fiber body in during removal from the suction mold, transfer to the compression mold, and removal from the compression mold. The positive pressure facilitates easy release of the fiber body from the transfer mold. Simultaneously, air can be blown through the porous wall of the suction mold to further assist in the release of the fiber body.

[0046] In practice, the suction mold, the compression mold, and / or the counter-mold can be heated. Heating the suction mold can serve to warm the raw materials to a predetermined temperature at which they are particularly easy to process and the fibers adhere especially well to one another. Specifically, the suction mold, the compression mold, and / or the counter-mold can be heated to a temperature of 130°C to 300°C, and preferably from 180°C to 240°C. These temperature ranges are above the melting point of most waxes (especially carnauba wax and beeswax) as well as many sugars (especially glucose, sucrose, fructose, maltose, lactose, raffinose, stachyose) and starches, so that the wax and / or sugar / starch in the fiber mold can be liquid at the suction mold, the compression mold, and / or the counter-mold.If the fiber molded body contains water, the water will further evaporate from the fiber molded body at the temperatures of the above temperature windows and the fiber molded body will be dried.

[0047] In practice, the fiber-reinforced body can additionally be coated with a coating solution. The coating solution can contain at least one of the following components: Cellulose fibers; casein; whey; agar agar; psyllium husks.

[0048] If the fiber-based molded part contains moisture, coating can take place, particularly after the moisture has been removed. Coating can be achieved by spraying a coating solution onto the fiber-based molded part in the suction mold, the compression mold, the counter-mold, and / or in a coating station. Additionally or alternatively, the fiber-based molded part can also be immersed in a coating solution or coated with a coating solution in a coating station. The coating can also be applied as a partial coating to only a portion of the fiber-based molded part's surface.

[0049] A coating can impart advantageous properties to the fiber-reinforced molded body. For example, a colored layer or a water-repellent functional layer can be applied. The coating can also increase the density of the fiber-reinforced molded body and its resistance to moisture or aggressive substances. Finally, the coating can increase its strength. In this way, hard objects such as knives or forks can be formed from fiber-reinforced molded bodies.

[0050] The invention also relates to a device for producing a fiber-shaped body. The device comprises at least the following components: a chamber, at least one device for mixing fiber material with air to create a fiber material-air mixture in the chamber, at least one suction mold with a porous wall that can be inserted into the chamber for depositing and compacting fiber material from the fiber material-air mixture, wherein the contour of the porous wall corresponds to the contour of the fiber molded body to be produced, and at least one suction device.

[0051] The at least one suction device is connected to the suction mold in a flow-through manner, so that either a negative or positive pressure can be generated at the porous wall. The device can also have more than one suction mold. In this case, each of the suction molds is connected to the suction device or to a separate suction device in a flow-through manner. The porous wall of the suction mold can, in particular, have a three-dimensional contour with several wall sections, wherein the wall sections can be flat, convex, and / or concave. The suction mold can also have several wall regions, each forming a fiber mold body. The device can be used to carry out the process described above. The description of the device therefore also includes the features described above in connection with the process and their advantages.

[0052] In practice, the device for mixing the fiber material with air to form the fiber-air mixture can include a propeller and / or a vibrating membrane. The movement of the propeller or vibrating membrane allows the raw materials to be effectively and homogeneously mixed with the air in the chamber to form the fiber-air mixture, as described above.

[0053] In practice, the device may also include at least one of the following elements, the above description of which explains details of these elements and their associated effects: at least one suction mold carrier driven by an actuator; separate storage containers for the fiber material, water, sugar, starch, wax and / or lipids; at least one device for heating the fiber material, water, sugar, starch and / or wax; at least one device for mixing water, sugar, starch and / or wax with air; at least one transfer mold; at least one transfer mold carrier driven by an actuator; at least one press mold and at least one counter mold for pressing the fiber molded body; at least one device for heating the suction mold, the press mold and / or the counter mold; at least one coating station for coating the fiber molded body; at least one control unit.

[0054] All elements of the device can be functionally connected to the at least one control unit, so that the device can execute the process automatically.

[0055] Further practical embodiments and advantages of the invention are described below in connection with the drawings. They show: Fig. 1 a schematic representation of a device according to the invention for producing a plurality of fiber molded bodies; Fig. 2 a first partial representation of the device made of Figure 1 and the introduction of starting materials into the chamber; Fig. 3 the partial representation from Figure 2 and the suction of the starting materials to the suction forms; Fig. 4 the partial representation from Figure 2 with the formed fiber bodies; Fig. 5 the partial representation from Figure 2 with a transfer device over the fiber molds; Fig. 6 the partial view from Figure 2 and the removal of the fiber mold bodies from the suction mold; Fig. 7 the partial view from Figure 2 and the transfer of the fiber-shaped bodies into the transfer mold at a first time point; Fig. 8 a second partial view of the device made of Figure 1and the transfer of the fiber-shaped bodies into the transfer mold at a second point in time; Fig. 9 a third partial view of the device and the pressing of the fiber-shaped bodies into press molds; Fig. 10 the partial view from Figure 9 and the transfer of the pressed fiber bodies to a conveyor belt; Fig. 11, the partial illustration from Figure 9 and the fiber molded bodies placed on the conveyor belt.

[0056] The Figures 1 to 11The figures illustrate the process described herein and a device for carrying out the process. The figures show a device with which four fiber molded parts can be produced simultaneously. It should be noted that the process and the device according to the invention are not limited to the simultaneous production of four fiber molded parts. Rather, the number of fiber molded parts produced simultaneously can be adapted to the requirements. The following describes the production process using the example of one of the four fiber molded parts shown, wherein a suction mold is provided for each fiber molded part. It should be noted that a suction mold with multiple surface areas can also be used, with one fiber molded part being produced in each surface area. In the figures, identical components are designated with identical reference numerals.

[0057] To produce a fiber-shaped body 1, a suction mold 2 is first provided. The suction mold 2 is designed as a hollow body with a plurality of walls surrounding a cavity, one of which is porous. The suction mold 2 is arranged on a suction mold carrier 3, which supports a plurality of suction molds, such that the porous wall 4 of the suction mold 2 faces upwards. The contour of the porous wall 4 corresponds to the contour of the fiber-shaped body 1 to be produced. It is three-dimensional and comprises several wall sections, some of which are flat and others convex. In the example described here, the fiber-shaped body 1 and the porous wall 4 together have the contour of an egg carton or egg carton. The porous wall 4 of the suction mold 2 can either consist of a wire mesh or be formed using an additive manufacturing process.

[0058] On the side opposite the porous wall 4, the suction mold 2 has a suction opening (not shown) through which the pores of the porous wall 4 are fluidly connected to a suction device (not shown). This fluid connection is achieved by the fact that the suction mold carrier 3 is hollow, allowing air to flow into the suction mold carrier 3 and to the suction device through openings (not shown) located below the suction mold 2. The suction device is, for example, a pump.

[0059] Using the suction mold carrier 3, the suction mold 2 is inserted into an air-filled chamber 5 to form the fiber mold body 1. The suction mold 2 inserted into the chamber 5 is, for example, in Figure 2As shown, for the purpose of insertion, chamber 5 has a first opening at its bottom through which the suction mold 2 is inserted and which is completely closed by the suction mold carrier 3 when the suction mold 2 is inserted into the chamber. Alternatively, the suction mold carrier 3 can be arranged substantially entirely within chamber 5 and the opening closed by means of a separate device.

[0060] As also in Figure 2As shown, after the suction mold 2 is inserted into the air-filled chamber 5, a fiber-air mixture 6 is introduced into the chamber 5. The fiber-air mixture 6 comprises at least the components air and fiber. If the fiber does not have sufficient moisture, water can be added in the form of fine droplets or steam. The fiber-air mixture 6 can also contain the additives sugar, starch, and wax, wherein the sugar is preferably lactose and the wax can be a mixture of carnauba wax and beeswax. The fiber, water, sugar / starch, and wax are the starting materials from which the fiber mold 1 is formed. The fiber is stored in a first storage container 7. It is introduced into the chamber 5 in the form of solid particles through a first pipe 8 and a second opening in the ceiling of the chamber 5.When the fiber material is sprinkled in, it mixes with the air already present in chamber 5 to form the fiber-air mixture 6. The particle size of the fibers can be 10 µm or smaller, so that the fiber material remains suspended in the air in chamber 5 as airborne particles, and the fiber-air mixture 6 is an aerosol. Alternatively, significantly longer fibers can be used, for example, with a length of approximately 200 µm, which sink to the absorbent form after being sprinkled in.

[0061] The water is stored in a second reservoir 9. It is heated by a first heating device (not shown) until it evaporates and then flows as steam through a second pipe 10 and through the second opening into chamber 5. Alternatively, instead of introducing the water into chamber 5 as steam, the water can also be sprayed into chamber 5 as droplets. For this purpose, a pump (not shown) can pump the water from the second reservoir 9 through the second pipe 10 to the second opening, where the water can then be sprayed into chamber 5, for example, by means of a nozzle. The second pipe 10 serves as the water supply device. The first heating device is then not required, but can be used optionally to spray heated water droplets into chamber 5.The sugar is stored in a third storage container 11 and introduced into chamber 5 as solid particles through a third pipe 12 and the second opening. The wax is stored in a fourth storage container 13 and introduced into chamber 5 as solid particles through a fourth pipe 14 and the second opening. The introduction of the different starting materials into chamber 5 can occur simultaneously or sequentially. If the fiber material is introduced as suspended particles, the sugar and wax particles can also be small enough to remain suspended, at least briefly, in the fiber-air mixture 6. This causes the air, fiber material, water vapor, sugar particles, and wax particles in chamber 5 to mix into the fiber-air mixture 6 without any targeted or active intervention. During this mixing process, the vapor moistens the fiber material and the sugar.This causes the starch in the fibers and the sugar to dissolve.

[0062] It is also possible to agitate the air or the fiber-air mixture 6 in chamber 5 using a device (not shown) for mixing the fiber material with air, in the form of a propeller or a vibrating membrane. This allows the raw materials to be distributed even more effectively and uniformly in the air. In particular, the fiber-air mixing device can create a flow of the fiber-air mixture 6 from the bottom of chamber 5 towards the top, thus generating a fluidized bed in chamber 5. This also enables the processing of significantly larger particles, which would otherwise settle in the air without the agitation device.

[0063] Figure 3Figure 1 shows the suction of the fiber-air mixture 6 through the porous wall 4 of the suction mold 2 and the compaction of the fiber material and additives to form the fiber body 1 against the wall 4. First, the second opening in the ceiling of chamber 5 is closed. Then, as described above, the air in the fiber-air mixture 6 is drawn out through the pores in the porous wall 4. During this process, the moistened fiber material, the moistened sugar, and the wax are deposited on the porous wall 4 because the pores are smaller than the fibers, sugar particles, and wax particles. The fiber material, sugar, and wax are deposited and compacted on the porous wall 4. While these particles are being deposited, the porous wall 4 of the suction mold 2 is heated to a temperature in the range of 180°C to 240°C, for example, 200°C, by means of a second heating device.This causes the water from the moistened starting materials to evaporate very quickly, and the fiber-shaped body dries. Some of the evaporated water is drawn off by the suction mold 2, and some is returned to the fiber-air mixture 6. Simultaneously, the sugar and wax particles deposited on the suction mold 2 melt, so that these additives, in liquid form, coat the fibers. The [unclear text] Figure 3 The fiber-shaped body shown (1) is not yet finished. After a certain absorption time, the resulting structure is formed in the manner described here. Figure 4 The illustrated finished, deposited fiber-shaped bodies 1 are formed with uniformly distributed raw materials and a desired wall thickness.

[0064] Optionally, the suction process can be carried out with a first fiber-air mixture 6 during an initial suction phase and with a second suction phase using the same fiber-air mixture 6. The second mixture can have a different composition than the first. In this way, two layers with different properties, such as color, density, water resistance, etc., are formed on the suction form 2.

[0065] Once the fiber-shaped body 1 has been formed on the porous wall 4, it is removed from the suction mold 2. In Figures 4 to 7 It has been shown that for this purpose a third opening is first opened in a side wall of chamber 5 ( Figure 4 ). Through the third opening, a transfer form 15, which is arranged on a transfer form carrier 16, is inserted into the chamber 5 and placed above the suction form 2 and the fiber forming body 1 ( Figure 5). The transfer form carrier 16 is lowered and the transfer form 15 is brought into engagement with the suction form 2 in such a way that a porous wall (not shown) of the transfer form 15 lies flat against the fiber forming body 1 ( Figure 6 The fiber-shaped body 1 is thus located between the porous wall 4 of the suction mold 2 and the porous wall of the transfer mold 15. The transfer mold 15 can be pressed axially against the suction mold 2, so that the fiber-shaped body 1 located between them is compacted even before removal. This is particularly true if the porous wall of the suction mold 2 is stable, e.g., if it was manufactured using additive manufacturing from plastic or metal.

[0066] For removal, the fiber mold 1 is drawn in through the pores in the porous wall of the transfer mold 15, while air is blown through the pores in the porous wall 4 of the suction mold 2. The fiber mold 1 can thus be easily lifted from the transfer mold 15. Subsequently, the fiber mold 1 is removed from chamber 5 through the third opening using the transfer mold 15 ( Figure 7 ). The third opening is closed again, so that the above-described process for forming a fiber mold body can take place again on the suction mold 2 arranged in chamber 5.

[0067] The fiber form 1, removed from chamber 5 and held by transfer form 15, is transferred to a press form 17, as shown in Figure 8 and Figure 9As shown, the fiber body 1 is pressed in the press mold 17. For pressing, the transfer mold 15, with the fiber body 1 attached to it, is pressed against a porous wall (not shown) of the press mold 17, which is essentially complementary to the porous wall of the transfer mold 15. Thus, during pressing, the transfer mold 15 also functionally acts as a counter-mold for the press mold 17. The porous walls of the transfer mold 15 and the press mold 17 contain significantly fewer pores overall than the porous wall 4 of the suction mold 2. As a result, the surface of the porous walls of the transfer mold 15 and the press mold 17 is smoother than the surface of the porous wall 4 of the suction mold. During pressing, the fiber body 1 is compacted, moisture is forced out, and the fibers are pressed tightly together, increasing the strength and density of the fiber body 1.Furthermore, the desired final geometry is imprinted on the fiber molded body 1, e.g. by increasing the sharpness of any existing edges, and the surface of the fiber molded body 1 is smoothed.

[0068] After pressing the fiber-shaped body 1, it is transferred to a conveyor belt 18 using the transfer form 15, as shown in Figure 10 As shown. When the transfer mold 17 is positioned above the conveyor belt 18, the suction of the fiber forming body 1 is terminated and air is blown out through the porous wall of the transfer mold 17, so that the fiber forming body 1, as shown in Figure 11The fiber molding body 1 is placed on conveyor belt 18. Conveyor belt 18 transports the fiber molding body 1 to a coating station (not shown) where it is sprayed with a coating solution containing cellulose fibers, casein, whey, agar-agar, and / or psyllium husks. Alternatively, conveyor belt 18 can transport the fiber molding body 1 to an intermediate storage area.

[0069] The device elements described above are functionally connected to a control unit that monitors and controls the parameters of the process. In particular, the control unit controls the opening and closing of the first, second and third openings, the suction mold carrier, the supply of the raw materials into the chamber (e.g. time and quantity), the devices for heating the water and the suction mold, the device for mixing the fiber material with air (e.g. time and intensity), the suction of fiber material-air mixture through the suction mold (e.g. time and intensity), the transfer mold carrier (e.g. the movement and suction of the fiber mold body), the pressure in the press mold, and the movement of the conveyor belt.

[0070] By controlling these elements of the device, the process can be automated.

[0071] The features of the invention disclosed in this description, in the drawings, and in the claims can be essential for realizing the invention in its various embodiments, both individually and in any combination. The invention is not limited to the described embodiments. It can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. Reference symbol list

[0072] 1 Fiber mold body 2 Suction mold 3 Suction mold carrier 4 Porous wall of the suction mold 5 Chamber 6 Fiber material-air mixture 7 First storage container 8 First pipeline 9 Second storage container 10 Second pipeline, feed device 11 Third storage container 12 Third pipeline 13 Fourth storage container 14 Fourth pipeline 15 Transfer mold, counter mold 16 Transfer mold carrier 17 Press mold 18 Conveyor belt

Claims

1. A method for producing a molded fiber product (1), comprising the following method steps: - arranging in a chamber (5) a suction mold (2) with a porous wall (4) having a contour corresponding to the contour of the molded fiber product (1) to be produced, - introducing a fiber material-air mixture (6) into the chamber (5), the fiber material being distributed in the air in the form of solid particles, - suction of the fiber material-air mixture (6) through the porous wall (4) of the suction mold (2) and compacting the fiber material to form the molded fiber product (1) on the porous wall (4), - removing the molded fiber product (1) from the suction mold (2) and from the chamber (5) characterized in that the fiber material consists mainly of cellulose fibers, the fiber material being moist and / or water in the form of droplets or water vapor being added to the fiber material-air mixture.

2. Method according to claim 1, characterized in that - a first fiber material-air mixture (6) is introduced into the chamber (5) and sucked in, so that a first layer of fiber material is formed on the porous wall (4) of the suction mold (2); - at least one further fiber material-air mixture (6) is introduced into the chamber (5) and sucked in, so that at least one further layer of fiber material is formed on the porous wall (4) of the suction mold (2); - the layers of the fiber material are compacted to form the molded fiber product (1) on the porous wall (4) and the molded fiber product (1) is removed from the suction mold.

3. Method according to one of claims 1 or 2, characterized in that the porous wall (4) of the suction mold (2) has a three-dimensional contour with several wall sections.

4. Method according to one of claims 1 to 3, characterized in that the fiber material in the form of fiber dust is mixed with the air to form the fiber material-air mixture (6) and / or the fiber material-air mixture (6) is an aerosol, the fiber material being distributed in the air as solid suspended particles.

5. Method according to one of claims 1 to 4, characterized in that at least one of the following additives is added to the fiber material / air mixture (6): - sugar and / or starch, - wax, - lipids, - minerals.

6. Method according to claim 5, characterized in that the additives are stored in separate storage containers (9, 11, 13).

7. Method according to one of the preceding claims, characterized in that, after removal from the suction mold (2), the molded fiber body (1) is transferred into a press mold (17) and a counter mold (15) is pressed against the molded fiber body (1) arranged in the press mold (17).

8. Method according to claim 7, characterized in that the removal and / or transfer of the molded fiber body (1) from the suction mold (2) to the press mold (17) is carried out by means of a transfer mold (15).

9. Method according to one of the preceding claims, characterized in that the suction mold (2), the press mold (17) and / or the counter mold (15) are heated.

10. Method according to one of the preceding claims, characterized in that the molded fiber body (1) is additionally coated with a coating solution.

11. Device for producing a molded fiber product with - a chamber (5), - at least one device for mixing fiber material with air to produce a fiber material-air mixture (6) in the chamber (5), - at least one suction mold (2) which may be introduced into the chamber (5) and has a porous wall (4) for depositing and compacting fiber material from the fiber material-air mixture (6), the contour of the porous wall (4) corresponding to the contour of the molded fiber product to be produced, and - at least one suction device, characterized by at least one feeding device (10) for water in the form of droplets and / or water vapor,12. Device according to claim 11, characterized in that the device for mixing the fiber material with air comprises a propeller and / or an oscillating membrane.

13. The device according to any one of claims 11 or 12, characterized in that it has at least one of the following features: - at least one suction mold carrier (3) that may be driven by means of an actuator; - separate storage containers (7, 9, 11, 13) for the fiber material, water, sugar, wax and / or lipids; - at least one device for heating the fiber material, water, sugar and / or wax; - at least one device for mixing water, sugar and / or wax with air; - at least one transfer mold (15); - at least one transfer mold carrier (16) which may be driven by an actuator; - at least one press mold (17) and at least one counter mold (15) for pressing the molded fiber product; - at least one device for heating the suction mold, the press mold and / or the counter mold; - at least one coating station for coating the molded fiber product; - at least one control unit.