Method and apparatus for producing fibre molded article

Abstract

The invention relates to a method for producing a fibrous molded article (1), comprising the following method steps: arranging a suction mold (2) having a porous wall (4), the contour of which corresponds to the contour of the fibrous molded article (1) to be produced, in a chamber (5), introducing a fibrous material-air mixture (6) into the chamber (5), the fibrous material is distributed in the form of solid particles in the air, the fibrous material-air mixture (6) is sucked through a porous wall (4) of a suction mold (2) and the fibrous material is compacted on the porous wall (4) to form a fibrous molded article (1), and the fibrous molded article (1) is removed from the suction mold (2) and the chamber (5). The problem addressed by the invention is that of providing a technically simple method and a technically simple device, which enable a rapid and energy-saving production of biodegradable fibrous moldings with particularly low rejection rates. For this purpose, the fibrous material consists essentially of cellulose fibres, the fibrous material being moist and / or water being mixed in the form of droplets or water vapour into a fibrous material-air mixture.

Description

Technical Field

[0001] The invention relates to a method for producing a fiber molding and an apparatus for producing a fiber molding. Background Art

[0002] Fiber moldings are used in various ways, in particular as transport packaging and for the protection of sensitive goods. For example, fiber moldings are used as an alternative to plastic pallets, as molded liners in packaging, and as food packaging.

[0003] It is known that fiber moldings are produced by a fiber injection molding method. Here, a suction mold with a porous wall is immersed in a slurry, also called a fiber suspension. The slurry usually contains at least water and fibers, which are sucked by the suction mold. The fibers usually consist of cellulose. The suction is achieved by holes or openings that are smaller than the fibers and are provided in the porous wall of the suction mold. Therefore, only the water of the slurry is sucked through the wall of the suction mold, while the fibers are deposited on the wall of the suction mold. The fiber content is increased and compacted at the wall of the suction mold, so that a fiber molding is formed there. After the fiber molding is removed, the dry matter content is further increased by subsequent drying, whereby the fiber molding is solidified.

[0004] The fiber injection molding method allows the production of fiber moldings with complex contours on a suction mold. However, the drying of the moist fiber moldings is very time-consuming and energy-intensive, since the fiber moldings deposited on the walls of the suction mold have a very high water content. The water must be evaporated essentially completely so that the fiber molding formed can be used. The water consumption and energy consumption for the fiber injection molding method are very high.

[0005] Alternatives to fiber injection molding methods are known in the prior art. For example, patent document SE 541 995 C2 discloses a method for manufacturing uneven fiber moldings known as cellulose products. The method includes dry molding cellulose fibers into flat cellulose webs in a drying molding unit. For dry molding of the cellulose webs, the drying molding unit has a separation unit for separating cellulose fibers, a molding screen for molding webs from cellulose fibers, and a compacting unit for compacting cellulose fibers. Water and one or more additives are added to cellulose fibers and / or cellulose blanks. The molding of cellulose products is achieved by heating the cellulose webs to a molding temperature in the range of 140°C to 200°C and squeezing the cellulose blanks with a molding pressure of at least 4 MPa. Here, one or more additives are spread on the cellulose fibers and / or cellulose webs in a solid form. Therefore, in the method, the manufacture of uneven fiber moldings is achieved by bending the flat cellulose webs.

[0006] Patent document EP 3 889 347 A1 also discloses a method for producing fiber molded products, which are called molded products. The method 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 wetted at least once and the wetted mixture is formed into a molded product by pressure loading and heating. The wetted mixture is deposited on a mesh conveyor belt in particular and is enriched there. The fiber web is fed into a molding device via a conveyor belt, in which the fiber web is squeezed. In the method, the production of the fiber molded product is also achieved by bending a flat fiber web.

[0007] The production of a fiber web, which is subsequently placed in a mold for the fiber molding to be produced, is very time-consuming and energy-intensive. In addition, during the extrusion, the fiber web may be reduced and / or torn into a specific shape, since the extrusion is associated with a large deformation of the fiber web.

[0008] Patent documents US Pat. No. 5,376,327 A and DE 10 2015 200 275 A1 describe methods for producing fiber moldings having carbon fibers and plastic fibers. Summary of the invention

[0009] The object of the present invention is to provide a technically simple method and a technically simple device which allow rapid and energy-saving production of biodegradable fiber moldings with particularly low scrap rates.

[0010] This object is achieved according to the invention by a method having the features of claim 1 and by a device having the features of claim 10. Advantageous embodiments are given by the dependent claims.

[0011] The method described here for producing a fiber molding comprises the following method steps:

[0012] - arranging a suction mold with a porous wall in the chamber, the contour of which corresponds to the contour of the fiber molding to be produced,

[0013] - placing the fiber material-air mixture into a chamber, wherein the fiber material is distributed in the air in the form of solid particles,

[0014] - sucking the fiber material-air mixture through the porous wall of the suction mold and compacting the fiber material on the porous wall to form a fiber molding,

[0015] - Remove the fiber molding from the suction mold and cavity,

[0016] - wherein the fiber material consists essentially of cellulose fibers and wherein the fiber material is moist and / or water is admixed in the form of droplets or water vapor into the fiber material-air mixture.

[0017] The invention is based on the idea that the raw material (especially fiber material) from which the fiber molding is formed is deposited directly from the air onto the porous walls of the suction mold and compacted there, so that the fiber molding has the geometry (contour) to be manufactured directly after the deposition and compaction of the raw material or at least substantially has the geometry (contour) to be manufactured.

[0018] The fiber molding is formed from raw materials that are biodegradable and preferably compostable. Thus, depending on the requirements for the visual properties of the fiber molding, the fiber material is mainly formed from cellulose, other recyclable fibers and / or fresh fibers, which are respectively biodegradable and preferably compostable. The fiber molding itself is thus also biodegradable and preferably compostable. The fibers can be mainly composed of cellulose, as is known in conventional production of fiber moldings using a fiber injection molding method (English: pulp molding). However, other fibers, such as hemp fibers, can also be used. This makes it possible to produce fiber moldings with higher strength and good mechanical properties. Depending on the application, the fibers can be mixed from different raw materials.

[0019] The fiber material can be introduced into the fiber material-air mixture in a slightly moistened state so that the fiber material is bonded during compacting (or compression) to form the molded article to be formed. The moisture content of the fiber material can cause problems when the fibers are swirled in the air. For this reason, water in the form of droplets or water vapor can be mixed into the swirled fiber material-air mixture in order to achieve an optimal moisture content for the bonding of the fibers during compacting. It is also possible to swirl completely dry fibers with air and to supply the entire amount of water required for bonding to the swirled fiber material-air mixture.

[0020] In some embodiments, the first fiber material-air-mixture can be placed in the chamber and sucked, so that the first fiber material layer is formed on the porous wall of the suction mold, and at least one other fiber material-air-mixture can be placed in the chamber and sucked, so that at least one other fiber material layer is formed on the porous wall of the suction mold. The fiber material layer can be compacted into a fiber molded product on the porous wall and the fiber molded product can be taken out of the suction mold. In other words, the first mixture can be input into the chamber, the first mixture forms a first layer on the porous wall, and then the second mixture can be input, and the second mixture forms a second layer on the first layer. This process can be repeated with the third layer and the fourth layer, etc. if necessary. Here, in order to form different layers, the fiber material-air-mixture can be different. The first fiber material-air-mixture can, for example, have a colorant different from the second fiber material-air-mixture. Thus, the outer layer of the formed molded product has a different color from the inner layer. Different additives can also be added to these layers. If, for example, the fiber molded product should be used for food packaging, the inner layer can be composed so that it has no problem in direct contact with the food. A second layer can be deposited on the inner layer, which gives the fiber molding a certain degree of impermeability or strength, but which is not suitable for direct contact with foods. It is also possible to form multi-layered moldings, in which each layer has its own function, for example, a higher degree of impermeability to oxygen, a higher degree of moisture resistance, a higher degree of light resistance. These different properties in the different layers can be achieved by varying the composition of the fiber material-air mixture in each case in order to produce a layer with the specific desired properties.

[0021] The suction mold can be, for example, a hollow body having a porous wall and a suction opening that can be connected to the holes of the wall in a flow-through manner, and the suction opening is used to connect a suction device. Alternatively, the suction mold can be designed as a main body formed by a porous structure, which has a suction opening for connecting a suction device. In this case, the surface of the main body or at least one surface section forms the porous wall of the suction mold. The contour of the porous wall corresponds to the contour of the fiber molding to be manufactured. In other words, the surface geometry of the porous wall or the section of the porous wall is complementary or substantially complementary to the surface geometry of the fiber molding to be manufactured. With the help of a suction device that can be connected to the suction mold, negative pressure or overpressure can be selectively generated in the suction mold and air can be sucked or blown out through the holes of the porous wall of the suction mold. The holes in the porous wall are preferably designed so that when the fiber material-air-mixture is sucked, the fiber material is deposited on the wall.

[0022] The porous wall of the suction mold can be formed by a metal wire mesh, for example. But the porous wall can also be made into a solid wall with air channels by an additive manufacturing method (3D printing), for example. In the second case, the suction mold has greater stability.

[0023] The chamber is a predefined space in which the fiber molding is formed on the porous wall of the suction mold. The space can have a surrounding wall with one or more openings, wherein the raw material for forming the fiber molding and / or the suction mold can be introduced into the space through the openings. The openings in the surrounding wall are at least partially closable, for example, by means of a door, a flap or a slide. The surrounding wall and the at least partially closable openings effectively prevent the fiber material-air mixture from flowing out into the air outside the chamber.

[0024] The arrangement of the suction mold in the chamber can be realized manually or automatically. The automatic arrangement can be realized by automating the method described herein. For example, the automatic arrangement can be completed by a suction mold carrier, and the suction mold carrier can be moved by an actuator that can be driven electrically or pneumatically. The drive device of the actuator can be functionally connected to the control unit. For example, the suction mold carrier can be designed as a conveyor belt, and the suction mold is arranged on the conveyor belt and the suction mold is moved from the supporting position to the chamber by the conveyor belt. Alternatively, the suction mold carrier can be a robot arm, for example.

[0025] In the method described here, a plurality of suction molds with identically or differently designed porous walls can also be arranged simultaneously in the chamber, so that a plurality of fiber moldings with identically or differently designed contours can be formed simultaneously. For small fiber moldings, each fiber molding can also correspond to one of a plurality of sections of the porous wall of the suction mold. The simultaneous production of a plurality of fiber moldings can enable the production of a plurality of fiber moldings to be carried out particularly quickly and energy-savingly.

[0026] Before, during or after the suction mold is arranged in the chamber, the fiber material-air mixture is placed in the chamber. For this purpose, the fiber material-air mixture can be premixed outside the chamber, so that the fiber material is already distributed in the air in the form of solid particles when it is placed. In this case, for example, the fiber material-air mixture can be blown into the chamber. Alternatively, the fiber material and the air can be placed in the chamber separately. For example, the fiber material can be continuously sprinkled into the chamber filled with air during the molding process, or it can be poured into the chamber filled with air as a filler at one time.

[0027] Thus, the desired fiber molding is formed directly in a single forming step by the method described here, without first producing an intermediate product that requires further processing. This saves a great deal of time. In addition, the fiber molding formed contains virtually no moisture and therefore does not need to be dried. Water, if any, only needs to be added to the extent that is necessary for the components of the fiber molding wall to achieve an optimal bond.

[0028] Regardless of the way in which the fiber material is placed, it may be advantageous that the air, the fiber material and / or the fiber material-air-mixture are actively and purposefully moved in the chamber in order to achieve a uniform mixing of the air and the raw material from which the fiber molding is formed. The active and purposeful movement of the air, the fiber material and / or the fiber material-air-mixture is achieved by a device, such as a propeller, for mixing the fiber material with the air. The propeller stirs the air and / or the fiber material-air-mixture so that the fiber material is evenly distributed in the air. The propeller can especially produce an upwardly directed airflow. A fluidized bed can thus be formed in the chamber. A fluidized bed is a bulk deposit of solid particles that is lifted and enters a fluidized state by an upwardly directed flow of a fluid. The term "fluidization" refers to the fact that the (previous) bulk deposit has fluid-like properties. As an alternative or supplement to the propeller, the device for mixing the fiber material with the air can, for example, have a vibrating membrane, wherein the vibrating membrane lifts the air, the fiber material-air-mixture and / or the raw material particles deposited on the vibrating membrane in front of it by vibration.

[0029] To form the fiber molding, air is sucked through the porous walls of the suction mold. In the process, the fiber material is deposited on the porous walls. After a certain suction time, due to the suction of the fiber material-air mixture, the fiber material is compacted on the porous walls and forms a fiber molding with the desired contour and wall thickness.

[0030] When a predetermined suction time and / or a desired wall thickness of the fiber molding is reached, the fiber molding is removed from the suction mold and the chamber and processed further or placed in an intermediate storage facility.

[0031] In practice, the porous wall of the suction mold can have a three-dimensional profile with a plurality of wall segments. The wall segments of the suction mold define different segments of the molded product to be manufactured. Each individual wall segment can extend flat, be convex and / or concave. Thus, a three-dimensional fiber molding with a plurality of surface segments on the porous wall can be formed, for example a cup-shaped fiber molding with a flat bottom and a cylindrical cup wall. As described above, a plurality of fiber moldings can also be formed on a plurality of surface segments of the suction mold.

[0032] In addition, in practice, the fiber material can be mixed with air in the form of fiber dust or short fibers to form a fiber material-air-mixture and / or the fiber material-air-mixture can be an aerosol, wherein the fiber material is distributed in the air as suspended particles. Fiber materials with fibers less than 500 μm and preferably less than 200 μm are called fiber dust. If the fibers of the fiber material are even less than 20 μm and further preferably less than 10 μm, the fiber material-air-mixture can be an aerosol. Aerosols are mixtures composed of solid suspended particles and / or liquid suspended particles in a gas. The fiber material is thus suspended in the air, sinking only very slowly and not falling in a few seconds in particular. In the case of an aerosol, the fiber material is regularly and evenly distributed in the air so that it can be deposited on the porous wall of the suction mold in a particularly evenly distributed manner in the method. In order to distribute the fiber material in the air, the aerosol requires at most the fiber material-air-mixture to be occasionally actively and purposefully moved. Therefore, the formation of fiber moldings is technically simple and particularly energy-saving. Furthermore, the very small fiber material particles of the aerosol can achieve high-quality properties of the fiber moldings to be produced therefrom. For example, the fiber moldings can have particularly high strength, high impermeability and / or high resistance to moisture or aggressive substances. However, it is also possible to process significantly longer fibers. This requires more intense swirling so that the fibers are deposited evenly on the porous surface of the suction mold. In particular, when processing hemp fibers, greater fiber lengths can be achieved.

[0033] In practice, at least one of the following additives can also be admixed to the fiber material-air mixture:

[0034] - sugar and / or starch,

[0035] - wax,

[0036] - lipids,

[0037] - Minerals.

[0038] The additive may also be a raw material for forming the fiber molding. If at least one of the additives is provided, air and raw materials (i.e., fiber material and at least one additive) are sucked by the suction mold, and the raw materials are deposited together on the porous wall of the suction mold. Thus, the fiber molding is formed by uniformly distributed raw materials. The additive may further improve the properties of the fiber molding, in particular, may further improve the strength, impermeability and / or moisture resistance.

[0039] If the swirled fiber material itself is not moist enough, water can be added in the form of droplets or as a water vapor mixture. The water can be deposited on the surface of the fiber material and / or penetrate into the fiber material. The adhesion of water can increase the adhesion of the fibers deposited on the porous wall to each other. In addition, the water can dissolve the fiber material, thereby further increasing the adhesion of the fibers. In short, a stable fiber composite material can be formed, which makes it easy and safe to remove the fiber molding from the suction mold. The strength of the fiber molding produced can also be increased in this way. However, the water content of such fiber moldings is much lower than when made with fiber pulp.

[0040] The raw material can also contain sugar, especially glucose, sucrose, fructose, maltose, lactose, raffinose, stachyose, and starch or a mixture of at least two of the above-mentioned components. It is also possible to mix sugar or starch in the form of solid particles, in particular. In the case where sugar or starch is first heated, melted and / or dissolved due to moisture and then cooled or dried again in the fiber molding, sugar or starch can also be used to increase the adhesion between the fibers deposited on the porous wall. Sugar or starch is thus used as a natural adhesive, which bonds the fibers of the fiber molding. Sugar or starch can additionally increase the hardness and wear resistance of the fiber molding, because the hardness of sugar crystals is usually greater than the hardness of most fiber materials, in particular greater than the hardness of cellulose fibers.

[0041] The wax can be mixed in the form of solid particles or droplets. In particular, palm wax and / or beeswax can be mixed. Palm wax is a very hard tropical wax with a very high melting point (about 85-89°C). Palm wax itself has almost no smell or taste and is waterproof. Palm wax is very brittle in a dry state and hardens within a few seconds. Due to its hardness, palm wax is also very wear-resistant. Palm wax is approved for food packaging and has long been used as a coating to extend the shelf life of mangoes, candies, etc. Wax can additionally contain beeswax or other natural waxes. A combination of biodegradable and compostable waxes can be used, which makes the fiber moldings have high strength and are particularly suitable for packaged food. In addition to palm wax and beeswax, shellac wax and sugarcane wax are also suitable. Beeswax is a wax mainly produced in Europe and has a lower hardness than palm wax. In mixing with palm wax, beeswax helps to reduce brittleness. Beeswax itself also has almost no smell or taste and is approved for use in combination with food. The melting point of beeswax is about 65°C.

[0042] The lipid can also be mixed in the form of solid particles or liquid droplets. The lipid is hydrophobic. Therefore, if the lipid is contained in the fiber molding, the wettability of the fiber molding can be reduced and / or the moisture barrier of the fiber molding can be increased.

[0043] It should be noted that the enumeration of additives is not exhaustive. Further additives, such as minerals or proteins, and also colorants can also be mixed into the swirled fiber-air mixture. The additives to be mixed in are selected depending on the product to be manufactured and, in particular, the desired product properties.

[0044] The size of the additive added as solid particles or liquid droplets is selected so that the additive is uniformly distributed in the chamber together with the fiber material, so that the fiber material-air mixture contains the additive in a uniformly distributed manner. Since the additive is deposited and compacted together with the fiber material as required, the additive added as solid particles or liquid droplets is preferably larger than the holes in the porous wall of the suction mold. If the fiber material is mixed with the air as fiber dust, the particle size of the additive preferably corresponds to the particle size of the fiber material. If the fiber material-air mixture is an aerosol, the particle size of the additive can be selected to be very small in particular, so that the additive is suspended in the chamber together with the fibers, so that the fiber material-air mixture containing the additive is an aerosol as a whole. The particle size of the additive can be less than 20 μm and preferably less than 10 μm. The water can be in the form of steam in particular.

[0045] In practice, the additive can be stored in a separate storage container. Here, the additive can be mixed with the fiber material before the raw material is placed in the chamber. Alternatively, the fiber material and the additive stored in the separate storage container can be placed separately in the chamber, which achieves particularly high flexibility. For example, the fiber material can be placed as described above, and the additive can be mixed with air in the separate storage container to form a separate additive-air-mixture, fluidized and then fed into the chamber as a separate air flow through a pipeline. Through the swirling of these air flows in the chamber, the additive is evenly mixed with the fibers and the air in the chamber to form a fiber material-air-mixture.

[0046] The fiber molding can be removed from the suction mold by means of a transfer mold. To this end, the transfer mold can have a wall that is substantially complementary to the porous wall of the suction mold and can press the wall against the fiber molding formed on the porous wall of the suction mold with a certain pressure. This can compact the fiber molding. In particular, if the porous wall of the suction mold is formed by an additive manufacturing method and has a large wall thickness, a higher strength of the formed fiber molding can be achieved by pressing the suction mold and the transfer mold together.

[0047] In practice, after removal from the suction mold, the fiber molding can be transferred to a pressure mold and the mating mold can be pressed against the fiber molding arranged in the pressure mold. The pressure mold has a wall whose contour substantially corresponds to the contour of the porous wall of the suction mold. The wall of the pressure mold preferably has no holes or has smaller and / or fewer holes than the porous wall of the suction mold. The wall of the pressure mold is preferably smooth. The mating mold has a wall that is substantially complementary to the wall of the pressure mold and is preferably also smooth. The mating mold can also have holes.

[0048] By pressing the mating mold against the fiber molding arranged in the pressure mold, the fiber molding can be sandwiched between the walls of the pressure mold and the walls of the mating mold over the entire surface, and the fiber molding can be squeezed and further compacted by mechanical pressure. Since the walls of the pressure mold and the mating mold are essentially complementary, the contour of the fiber molding can be easily changed. In particular, small steps and / or undercuts can be provided. In addition, pressing the mating mold against the fiber molding can produce a uniform wall thickness of the fiber molding. By squeezing, the surface of the fiber molding can be particularly smooth, so that the fiber molding can have a high-quality appearance. If the fiber molding contains residual moisture, the water can be squeezed out of the fiber molding. However, unlike the fiber molding made of slurry, the fiber molding made according to the present invention has a very low water content and only needs to be dried slightly if drying is required.

[0049] After the pressing mold and the counter mold are pressed together, the pressing mold and the counter mold can be separated from each other. The counter mold is no longer engaged with the pressing mold. The fiber molding can be removed and further processed.

[0050] In practice, it is also possible to extrude the fiber molding in multiple steps. For this purpose, the fiber molding can be extruded in a first compression mold with a first mating mold after extrusion in the suction mold and the transfer mold. If necessary, the fiber molding can be transferred to a second compression mold and extruded with a second mating mold. Further extrusion can be performed similarly. Multiple extrusions in different compression molds can continuously increase the density and / or continuously improve the surface quality of the fiber molding.

[0051] In practice, the removal of the fiber molding and / or the transfer of the fiber molding from the suction mold to the pressure mold can be achieved as described above with the help of a transfer mold. The wall of the transfer mold is basically complementary to the porous wall of the suction mold. The transfer mold can be arranged on a transfer mold carrier, which can be driven by an actuator and functionally connected to a control unit. The transfer mold can be engaged with the suction mold so that the wall of the transfer mold is against the fiber molding and removes it from the suction mold. Then, the transfer mold transfers the fiber molding to an intermediate storage facility or a pressure mold. The transfer mold can also be used to transfer the fiber molding from a first pressure mold to other pressure molds. In practice, the transfer mold can be the above-mentioned matching mold, which is used to press the fiber molding on the porous wall of the suction mold and / or the pressure mold.

[0052] The wall of the transfer mold can have holes, wherein the holes are connected to the suction device in a flow-through manner in order to generate negative pressure or overpressure at the holes. During removal from the suction mold, transfer to the pressure mold and removal from the pressure mold, the negative pressure sucks the fiber molding. The overpressure makes it possible to easily separate the fiber molding from the transfer mold. At the same time, air can be blown in through the porous wall of the suction mold to support demoulding of the fiber molding.

[0053] In practice, the suction mold, the compression mold and / or the matching mold can be heated. The heated suction mold can be used to heat the raw material to a predetermined temperature, at which the raw material can be processed particularly well and the fibers are particularly well attached to each other. In particular, the suction mold, the compression mold and / or the matching mold can be heated to a temperature of 130°C to 300°C and preferably 180°C to 240°C. The temperatures in these temperature ranges are higher than the melting points of most waxes (especially palm wax and beeswax) and many sugars (especially glucose, sucrose, fructose, maltose, lactose, raffinose, stachyose) or starch, so the wax and / or sugar / starch in the fiber molded product can be liquid on the suction mold, the compression mold and / or the matching mold. In addition, if the fiber molded product contains moisture, the moisture will evaporate from the fiber molded product at the temperature in the above-mentioned temperature window, and the fiber molded product will be dried.

[0054] In practice, the fiber molding may be additionally coated with a coating solution. The coating solution may contain at least one of the following components:

[0055] - cellulose fibers;

[0056] - Casein;

[0057] - Whey;

[0058] - agar;

[0059] - Psyllium husk.

[0060] If the fiber molding contains moisture, the coating can be carried out in particular after the moisture has been removed from the fiber molding. The fiber molding can be coated in particular by spraying the fiber molding with a coating solution in a suction mold, a pressure mold, a mating mold and / or a coating station. Additionally or alternatively, the fiber molding can also be dipped into the coating solution in the coating station or poured with the coating solution for coating. The coating can also be applied as a partial coating only to a portion of the surface of the fiber molding.

[0061] The coating can give the fiber molding advantageous properties. Thus, for example, a color layer or a waterproof functional layer can be applied. The coating can also increase the fiber molding's impermeability and resistance to moisture or aggressive substances. Finally, the coating can increase the strength. In this way, hard objects, such as knives or forks, can be formed from the fiber molding.

[0062] The present invention also relates to a device for manufacturing fiber moldings. The device has at least the following components:

[0063] - Chamber,

[0064] - at least one device for mixing the fibrous material with air in order to produce a fibrous material-air-mixture in the chamber,

[0065] - at least one suction mold which can be placed in the chamber and has a porous wall for depositing and compacting the fiber material from the fiber material-air mixture, wherein the contour of the porous wall corresponds to the contour of the fiber molding to be produced, and

[0066] - At least one suction device.

[0067] At least one suction device is connected to the suction mold in a flow-through manner so as to selectively generate negative pressure or overpressure on the porous wall. The device can also have more than one suction mold. In this case, each suction mold is connected to the suction device or a separate suction device in a flow-through manner. The porous wall of the suction mold can especially have a three-dimensional profile, which has a plurality of wall segments, wherein the wall segments can be designed flat, convex and / or concave. The suction mold can also have a plurality of wall areas that each form a fiber molding. The above method can be performed with the device. Therefore, the description of the device also includes the features and advantages described above in connection with the method.

[0068] In practice, the device can have a propeller and / or a vibrating membrane to mix the fiber material with air to form a fiber material-air-mixture. As described above, the raw material can be effectively and evenly mixed with the air in the chamber to form a fiber material-air-mixture by the movement of the propeller or the vibrating membrane.

[0069] In practice, the device may further include at least one of the following elements, wherein the above description further explains the details and related effects of these elements:

[0070] - at least one suction mold carrier that can be driven by an actuator;

[0071] - separate supply containers for the fibrous material, water, sugar, starch, wax and / or lipid;

[0072] - at least one device for heating the fibrous material, water, sugar, starch and / or wax;

[0073] - at least one device for mixing water, sugar, starch and / or wax with air;

[0074] - at least one transfer die;

[0075] - at least one transfer mold carrier capable of being driven by an actuator;

[0076] - at least one pressing die and at least one mating die for extruding the fiber molding;

[0077] - at least one device for heating the suction mold, the pressure mold and / or the matching mold;

[0078] - at least one coating station for coating the fiber moldings;

[0079] - At least one control unit.

[0080] All elements of the device can be functionally connected to at least one control unit, so that the device can automatically carry out the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Other practical implementations and advantages of the present invention are described below in conjunction with the accompanying drawings. In the accompanying drawings:

[0082] Figure 1 A schematic diagram showing an apparatus for producing a plurality of fiber moldings according to the present invention;

[0083] Figure 2 Show Figure 1 A first partial view of the apparatus and the process of placing raw materials into the chamber;

[0084] Figure 3 Show Figure 2 Partial view of the process of sucking raw materials onto the suction mold;

[0085] Figure 4 Show Figure 2 A partial view of a fiber molding having been formed;

[0086] Figure 5 Show Figure 2 A partial view of a fiber molding having a transfer device above the fiber molding;

[0087] Figure 6 Show Figure 2 A partial view of the fiber molding and removing the fiber molding from the suction mold;

[0088] Figure 7 Show Figure 2 A partial view of and the transport of a fiber molding in a transport mold at a first point in time;

[0089] Figure 8 Show Figure 1 A second partial view of the device in FIG. 1 and the transport of the fiber molding in the transport mold at a second point in time;

[0090] Fig. 9 A third partial view of the apparatus is shown with the extrusion of a fiber molding in a die;

[0091] Fig.10 Show Fig. 9 A partial view of the process of transferring the extruded fiber molding to a conveyor belt;

[0092] Fig.11 Show Fig. 9 Partial view of the fiber moldings placed on a conveyor belt. DETAILED DESCRIPTION

[0093] Figures 1 to 11 The flow of the method described here and a device for carrying out the method are shown. The drawing shows a device that can produce four fiber moldings simultaneously. It should be noted that the method and device according to the invention are not limited to the simultaneous production of four fiber moldings. On the contrary, the number of fiber moldings produced simultaneously can be adjusted as required. The production is explained below using one of the four fiber moldings shown as an example, wherein a suction mold is provided for each fiber molding. It should be noted that a suction mold with multiple surface areas can also be used, wherein a fiber molding is produced in each surface area. In the drawings, identical components are provided with identical reference numerals.

[0094] In order to manufacture the fiber molded product 1, a suction mold 2 is first provided. The suction mold 2 is designed as a hollow body having a plurality of walls surrounding the cavity, wherein one of the walls is a porous wall. The suction mold 2 is arranged on a suction mold carrier 3 carrying a plurality of suction molds so that the porous wall 4 of the suction mold 2 points upward. The contour of the porous wall 4 corresponds to the contour of the fiber molded product 1 to be manufactured. The porous wall is designed three-dimensionally and includes a plurality of wall sections, one of which is designed to be flat and the other is designed to be convex. In the example described here, the fiber molded product 1 and the porous wall 4 have the contour of an egg hump or an egg box as a whole. The porous wall 4 of the suction mold 2 can be composed of a wire mesh or formed in an additive manufacturing method.

[0095] On the side opposite to the porous wall 4, the suction mold 2 has a suction opening (not shown), through which the holes of the porous wall 4 are fluidically connected to a suction device (not shown). Here, the fluid connection is achieved in the following manner, that is, the suction mold carrier 3 is hollow and air can flow into the suction mold carrier 3 and flow to the suction device through an opening (not shown) arranged below the suction mold 2 in the suction mold carrier 3. For example, the suction device is a pump.

[0096] The suction mold 2 is placed into the air-filled chamber 5 for forming the fiber molding 1 through the suction mold carrier 3. Figure 2 2 shows the suction mold 2 placed in the chamber 5. In order to facilitate placement, the chamber 5 has a first opening at the bottom, through which the suction mold 2 is placed, and when the suction mold 2 is placed in the chamber, the suction mold carrier 3 completely closes the first opening. Alternatively, the suction mold carrier 3 can be basically completely arranged in the chamber 5, and the opening can be closed by a separate device.

[0097] As in Figure 2As shown in FIG. 2 , after the suction mold 2 is placed in the chamber 5 filled with air, a fiber material-air-mixture 6 is placed in the chamber 5. The fiber material-air-mixture 6 has at least air and fiber material as components. If the fiber material does not have enough moisture, water can be added in the form of small droplets or steam. The fiber material-air-mixture 6 can also have additives such as sugar, starch and wax, wherein the sugar is preferably lactose and the wax can be a mixture of palm wax and beeswax. The fiber material, water, sugar / starch and wax are the raw materials for forming the fiber molding 1. The fiber material is stored in a first storage container 7. The fiber material is sprinkled into the chamber 5 in the form of solid particles through the first pipeline 8 and the second opening in the top of the chamber 5. After the fiber material is sprinkled, the fiber material is mixed with the air already present in the chamber 5 to form the fiber material-air-mixture 6. The particle size of the fiber can be 10 μm or less here, so the fiber material is suspended in the air of the chamber 5 in the form of suspended particles, and the fiber material-air-mixture 6 is an aerosol. Alternatively, it is also possible to use longer fibers, for example fibers with a length of approximately 200 μm, which, after being cast in, sink onto the suction mold.

[0098] Water is stored in a second storage container 9. The water is heated by a first heating device, not shown here, until the water evaporates and then flows into the chamber 5 in the form of steam through the second pipe 10 and through the second opening. As an alternative to placing the water in the form of steam into the chamber 5, the water can also be sprayed into the chamber 5 in the form of droplets. For this purpose, a pump, not shown here, can pump the water from the second storage container 9 through the second pipe 10 to the second opening, and then spray the water into the chamber 5 there, for example, through a nozzle. The second pipe 10 forms an input device for water. The first heating device is thus not necessary, but can be used optionally so that the heated water droplets can be sprayed into the chamber 5. Sugar is stored in a third storage container 11 and is sprinkled into the chamber 5 in the form of solid particles through the third pipe 12 and the second opening. Wax is stored in a fourth storage container 13 and is sprinkled into the chamber 5 in the form of solid particles through the fourth pipe 14 and the second opening. The placement of different raw materials into the chamber 5 can be carried out simultaneously or sequentially. If the fiber material is introduced in the form of suspended particles, the sugar particles and wax particles can also be small enough that they are suspended in the fiber material-air mixture 6 at least for a short time. Thus, air, fiber material, water vapor, sugar particles and wax particles are mixed in the chamber 5 to form the fiber material-air mixture 6 without the need for targeted active assistance. During the mixing process, the steam moistens the fiber material and the sugar. This causes the starch and sugar in the fibers to dissolve.

[0099] It is also possible to roll up the air or the fiber material-air mixture 6 in the chamber 5 by means of a device (not shown here) in the form of a propeller or a vibrating membrane for mixing the fiber material with the air. This makes it possible to distribute the raw material more effectively and more evenly in the air. In particular, the device for mixing the fiber material can generate a flow of the fiber material-air mixture 6 directed from the bottom of the chamber 5 to the top of the chamber 5 and thus form a fluidized bed in the chamber 5. This also makes it possible to process significantly larger particles that sink in the air without the use of turbulence agents.

[0100] Figure 3 The process of sucking the fiber material-air-mixture 6 through the porous wall 4 of the suction mold 2 and compacting the fiber material and additives at the wall 4 to form a fiber molded product 1 is shown. To this end, the second opening in the top of the chamber 5 is first closed. Then, the air of the fiber material-air-mixture 6 is sucked through the holes in the porous wall 4 as described above. The moistened fiber material, moistened sugar and wax are deposited on the porous wall 4 here because the holes are smaller than the fibers, sugar particles and wax particles. The fiber material, sugar and wax are deposited on the porous wall 4 and compacted. During the deposition of these particles, 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 a second heating device. As a result, moisture evaporates rapidly from the moistened raw material and the fiber molded product becomes dry. The evaporated water is partially sucked away by the suction mold 2 and partially input into the fiber material-air-mixture 6 again. At the same time, the sugar particles and wax particles deposited on the suction mold 2 melt, so that these additives are deposited around the fibers in liquid form. In Figure 3 The fiber molding 1 shown in FIG. has not yet been completed. After a certain suction time, Figure 4 The deposited fiber molding 1 shown is formed in the manner described here with a uniform distribution of the starting material and the desired wall thickness.

[0101] The suction process can optionally be carried out with the first fiber material-air-mixture 6 during a first suction time and with the first fiber material-air-mixture 6 during a subsequent second suction time. The composition of the second mixture can be different from the first mixture. In this way, two layers with different properties, such as color, impermeability, water resistance, etc., are formed on the suction mold 2.

[0102] After the fiber molding 1 is formed on the porous wall 4, it is removed from the suction mold 2. Figures 4 to 7 As shown in FIG. 1 , for this purpose, a third opening is first opened on the side wall of the chamber 5 (see Figure 4 The transfer mold 15 arranged on the transfer mold carrier 16 is placed into the chamber 5 through the third opening and placed above the suction mold 2 and the fiber molded product 1 (see Figure 5). The transfer mold carrier 16 is lowered, and the transfer mold 15 is engaged with the suction mold 2 in such a way that the porous wall (not shown) of the transfer mold 15 lies flat against the fiber molded part 1 (see Figure 6 ). The fiber molding 1 is thus placed 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 against the suction mold 2 with axial pressure, so that the fiber molding 1 located between the two is already compacted before removal. This applies in particular if the porous wall of the suction mold 2 is stable, for example, it is made of plastic or metal by an additive manufacturing method.

[0103] For removal, the fiber molding 1 is sucked through the holes in the porous wall of the transfer mold 15, while air is blown in through the holes in the porous wall 4 of the suction mold 2. The fiber molding 1 can thus be easily lifted from the transfer mold 15. The fiber molding 1 is then removed from the chamber 5 through the third opening by means of the transfer mold 15 (see Figure 7 ). The third opening is closed again so that the above-described method for forming a fiber molding on the suction mold 2 arranged in the chamber 5 is carried out again.

[0104] like Figure 8 and Fig. 9 As shown, the fiber molding 1 taken out of the chamber 5 and held by the transfer mold 15 is transferred to the pressure mold 17. The fiber molding 1 is pressed in the pressure mold 17. For the pressing, the transfer mold 15 with the fiber molding 1 arranged thereon is pressed against the porous wall of the pressure mold 17 (not shown), which is substantially complementary to the porous wall of the transfer mold 15. Therefore, during the pressing process, the transfer mold 15 is also functionally a mating mold of the pressure mold 17. The number of pores contained in the porous walls of the transfer mold 15 and the pressure mold 17 is much smaller than the number of pores contained in the porous wall 4 of the suction mold 2 as a whole. As a result, the surface of the porous wall of the transfer mold 15 and the pressure mold 17 is smoother than the surface of the porous wall 4 of the suction mold. The fiber molding 1 is compacted by pressing, wherein moisture is squeezed out and the fibers are pressed tightly together, thereby increasing the strength and impermeability of the fiber molding 1. In addition, the fiber molding 1 is given the desired final geometry, for example by increasing the sharpness of any edges that may exist and making the surface of the fiber molding 1 flat.

[0105] like Fig.10 As shown in FIG. 1 , after the fiber molding 1 is extruded, the fiber molding 1 is transferred to the conveyor belt 18 by the transfer mold 15. When the transfer mold 17 is arranged above the conveyor belt 18, the suction of the fiber molding 1 is terminated and the air is blown away through the porous wall of the transfer mold 17, so that the fiber molding 1 is unloaded on the conveyor belt 18, as shown in FIG. Fig.11The conveyor belt 18 transports the fiber molding 1 to a coating station not shown here, in which the fiber molding 1 is sprayed with a coating solution containing cellulose fibers, casein, whey, agar and / or psyllium husk. Alternatively, the conveyor belt 18 can transport the fiber molding 1 to an intermediate storage facility.

[0106] The aforementioned elements of the device are functionally connected to a control unit which monitors and controls the parameters of the method. The control unit in particular controls

[0107] - opening and closing of the first, second and third openings,

[0108] - Suction mold carrier,

[0109] - the input of raw materials into the chamber (e.g. time point and quantity),

[0110] - a device for heating water and sucking the mould,

[0111] - the means for mixing the fibrous material with the air (e.g. timing and intensity),

[0112] - suction of the fiber-air mixture through the suction die (e.g. timing and intensity),

[0113] - transport of mould carriers (e.g. movement and suction of fibre mouldings),

[0114] - the pressure inside the die, and

[0115] - Movement of conveyor belts.

[0116] By controlling these elements of the device, the method can be run in an automated manner.

[0117] The features of the invention disclosed in the description, the drawings and the claims may be essential for the realization of the invention in its different embodiments both individually and in any combination. The invention is not limited to the described embodiments. The invention may be modified within the scope of the claims and taking into account the knowledge of the person skilled in the art.

[0118] List of Reference Numerals

[0119] 1 Fiber moldings

[0120] 2 suction mold

[0121] 3. Suction mold carrier

[0122] 4 Porous wall of the suction mold

[0123] 5 Chamber

[0124] 6 Fiber-Air-Mixture

[0125] 7 First storage container

[0126] 8 First pipeline

[0127] 9 Second storage container

[0128] 10 Second pipeline, input device

[0129] 11 Third storage container

[0130] 12 Third pipeline

[0131] 13 Fourth storage container

[0132] 14 Fourth pipeline

[0133] 15. Transfer mold, matching mold

[0134] 16 Transfer mold carrier

[0135] 17. Stamping

[0136] 18 Conveyor Belt

Claims

1. A method for producing a fiber molding (1), comprising the following method steps: - arranging a suction mold (2) with a porous wall (4) in the chamber (5), the contour of which corresponds to the contour of the fiber molding (1) to be produced, - placing the fiber material-air mixture (6) into the chamber (5), wherein: The fiber material is distributed in the air in the form of solid particles. - sucking the fiber material-air mixture (6) through the porous wall (4) of the suction mold (2) and compacting the fiber material on the porous wall (4) to form a fiber molding (1), - removing the fiber molding (1) from the suction mold (2) and the cavity (5), It is characterized in that the fiber material consists essentially of cellulose fibers, wherein the fiber material is moist and / or water is admixed in the form of droplets or water vapor into the fiber material-air mixture.

2. The 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 fiber material layer 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 fiber material layer is formed on the porous wall (4) of the suction mold (2); - Compacting the fiber material layer on the porous wall (4) to form a fiber molding (1) and removing the fiber molding (1) from the suction mold.

3. The method according to claim 1 or 2, characterized in that: The porous wall (4) of the suction mold (2) has a three-dimensional contour with a plurality of wall segments.

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

5. The method according to any one of claims 1 to 4, characterized in that In addition, at least one of the following additives is mixed into the fiber material-air mixture (6): - sugar and / or starch, - wax, - lipids, - Minerals.

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

7. The method according to any one of the preceding claims, characterized in that After being removed from the suction mold (2), the fiber molding (1) is transferred into a pressure mold (17) and a counter mold (15) is pressed onto the fiber molding (1) arranged in the pressure mold (17).

8. The method according to claim 7, characterized in that The removal of the fiber molding (1) and / or the transfer of the fiber molding (1) from the suction mold (2) to the pressure mold (17) are achieved by means of a transfer mold (15).

9. The method according to any one of the preceding claims, characterized in that The suction mold (2), the pressure mold (17) and / or the matching mold (15) are heated.

10. The method according to any of the preceding claims, characterized in that Additionally, the fiber molding (1) is coated with a coating solution.

11. An apparatus for manufacturing fiber molded products, comprising: - chamber (5), - at least one device for mixing the fiber material with air in order to produce a fiber material-air mixture (6) in the chamber (5), - at least one input device (10) for water in the form of droplets and / or water vapor, - at least one suction mold (2) which can be placed in the chamber (5), said suction mold having a porous wall (4) for depositing and compacting the fiber material from the fiber material-air mixture (6), wherein The contour of the porous wall (4) corresponds to the contour of the fiber molding to be produced, and - At least one suction device.

12. The device according to claim 11, characterized in that The device has a propeller and / or a vibrating membrane in order to mix the fiber material with the air.

13. The device according to claim 11 or 12, characterized in that The device has at least one of the following features: - at least one suction mold carrier (3) which can be driven by an actuator; - separate supply containers (7, 9, 11, 13) for the fibrous material, water, sugar, wax and / or lipid; - at least one device for heating the fibrous material, water, sugar and / or wax; - at least one device for mixing water, sugar and / or wax with air; - at least one transfer die (15); - at least one transfer mold carrier (16) which can be driven by an actuator; - at least one pressing die (17) and at least one mating die (15) for extruding the fiber molding; - at least one device for heating the suction mold, the pressure mold and / or the matching mold; - at least one coating station for coating the fiber moldings; - At least one control unit.

Images