Producing molded parts from fiber material, which fiber material is degradable in an environmentally friendly way

Abstract

The invention relates to a method (100) for producing molded parts (10) from fiber material (11) by means of a fiber molding process in a fiber molding system (20), which fiber material is degradable in an environmentally friendly way, the method comprising the following steps: providing (110) a pulp (1) as a liquid solution having fiber material that is degradable in an environmentally friendly way; bringing (120) a suction tool (2) into contact with the pulp by placing the suction tool onto the pulp or at least partially dipping the suction tool into the pulp, the suction tool comprising a suction head (21) having a three-dimensionally shaped suction head suction side (21i), the shape of which is adapted to the contour of the later molded part; molding (130) the molded part onto the suction head suction side (21i) by suctioning the fiber material by means of negative pressure in the suction tool; pre-pressing (140) the molded-on molded part in a pre-pressing station (3) with a pre-pressing pressure (VD) in order to reduce the proportion of the liquid solution in the molded part; hot pressing (150) the pre-pressed molded part with a hot-pressing pressure (HD) in a hot-pressing station (4) in order to finally mold the molded part and to further reduce the proportion of the liquid solution in the molded part; and outputting (160) the molded part (10) that has been finally molded. The invention further relates to such a fiber molding system for carrying out the method above and to a molded part produced by means of such a fiber molding system or by means of such a method.

Description

Field of invention

[0001] The invention relates to a method for producing molded parts from environmentally biodegradable fiber material by means of a fiber forming process in a fiber forming plant, such a fiber forming plant for carrying out the above method and a molded part produced with such a fiber forming plant or with such a method. Background of the invention

[0002] It is desirable to protect citizens and the environment from plastic pollution. In particular, single-use plastic products such as packaging materials, plastic cutlery, and plastic tableware generate a large amount of waste. Therefore, there is a growing need for alternative materials for plastic packaging and containers, enabling the production of these products from recyclable plastics, materials with a lower plastic content, or even plastic-free materials.

[0003] The idea of ​​using natural fibers instead of conventional plastics in extrusion processes has existed at least since the early 1990s; see, for example, EP 0 447 792 B1. The raw material basis here, as in most fiber processing processes, is pulp. In principle, pulp consists of water, natural fibers, and a binder such as industrial starch (potato starch) and has a pasty consistency.

[0004] From US Patent 2003 / 111201 A1, a method for producing molded parts from environmentally biodegradable fiber material by means of a fiber forming process in a fiber forming plant is known, comprising the following steps: providing a pulp as a liquid solution containing environmentally biodegradable fiber material; contacting a suction tool with the pulp by placing it into the pulp, wherein the suction tool comprises a suction head with a three-dimensionally shaped suction head suction side, the shape of which is adapted to a contour of the subsequent molded part; forming the molded part by suction onto the suction head suction side by means of a vacuum in the suction tool; pre-compression of the formed molded part in a pre-compression station with a pre-compression pressure to reduce a proportion of the liquid solution in the molded part;Hot pressing of the pre-molded part with a hot pressing pressure for final shaping of the part and for further reduction of the proportion of liquid solution in the part in a hot pressing station; and discharge of the final molded part. Such a process is also known from WO 2014 / 019027 A1.

[0005] WO 2006 / 057610 A2 discloses a method comparable to the aforementioned methods, in which the use of a microwave is proposed for drying, and finally EP 1 235 462 A1 discloses a device and a method in which, already in the forming step, when the fiber material is taken up from the pulp, additional geometries or elements, such as openings and recesses, are embossed into the molded part to be formed by means of a counter element.

[0006] Since consumers are interested in a wide variety of environmentally friendly products with different sizes, shapes and requirements, and do not necessarily demand these in very large quantities, it would be desirable to have a manufacturing process for environmentally friendly molded parts made from natural fibers and a corresponding machine available in order to be able to produce these products (molded parts) effectively, flexibly and reproducibly with good quality. Summary of the invention

[0007] The invention is based on the objective of providing a manufacturing process for environmentally friendly molded parts made from natural fibers and a corresponding machine with which these products (molded parts) can be produced effectively, flexibly and reproducibly with good quality.

[0008] The object of the invention is achieved according to claim 1 by a method for producing molded parts from environmentally biodegradable fiber material by means of a fiber forming process in a fiber forming plant comprising, among other things, the following steps: Providing a pulp as a liquid solution containing biodegradable fiber material; contacting a suction tool with the pulp by placing it on or at least partially immersing it in the pulp, the suction tool comprising a suction head with a three-dimensionally shaped suction head suction side whose shape is adapted to a contour of the subsequent molded part; forming the molded part by drawing the biodegradable fiber material onto the suction head suction side by means of a vacuum in the suction tool; pre-pressing the formed molded part in a pre-pressing station with a pre-pressing pressure to reduce the proportion of the liquid solution in the molded part; hot-pressing the pre-pressed molded part with a hot-pressing pressure to finalize the molded part and to further reduce the proportion of the liquid solution in the molded part in a hot-pressing station; and dispensing the final molded part.

[0009] The term "environmentally biodegradable fiber material" refers to fiber materials that decompose under environmental influences such as moisture, temperature, and / or light, with the decomposition process occurring in the short term, for example, within days, weeks, or a few months. For the sake of simplicity, the "environmentally biodegradable fiber material" will also sometimes be referred to simply as "fiber material" in the following. Ideally, neither the fiber material nor its decomposition products should pose any environmental hazard or cause contamination. Fiber materials that constitute an environmentally biodegradable fiber material within the meaning of the present invention include, for example, natural fibers obtained from pulp, paper, cardboard, wood, grass, plant fibers, sugar cane residues, hemp, etc., or from their components or parts thereof, and / or appropriately recycled material.An environmentally biodegradable fiber material can also refer to artificially produced fibers such as PLA (polylactic acid), etc., which correspond to or possess the properties of the aforementioned fiber materials. Preferably, the environmentally biodegradable fiber material is compostable. Preferably, the environmentally biodegradable fiber material and the containers manufactured from it are suitable for inclusion in the German organic waste recycling system and as a resource for biogas plants. Preferably, the fiber materials and the containers manufactured from them are biodegradable according to EU standard EN 13432.

[0010] The term "pulp" refers to fluid masses containing fibers, in this case, biodegradable fibrous material. The term "liquid" here describes the state of matter of the pulp, whereby the liquid pulp comprises the biodegradable fibrous material in the form of fibers. These fibers can be present as individual fibers, as fiber structures, or as groups of several interconnected fibers. The fibers constitute the fibrous material regardless of whether they are present in the pulp as individual fibers, as fiber structures, or as fiber groups. The fibers are dissolved in the liquid solution in such a way that they remain suspended in the liquid solution at as uniform a concentration as possible, regardless of their location, for example, as a mixture or suspension of liquid solution and fibrous material. In some embodiments, the pulp can be appropriately temperature-controlled and / or circulated to achieve this. The pulp preferably has a low density, i.e.,The pulp contains less than 8% fiber material. In one embodiment of the process according to the invention, a pulp with a proportion of environmentally friendly, biodegradable fiber material of less than 5%, preferably less than 2%, and particularly preferably between 0.5% and 1.0%, is used. This low proportion of fiber material can, among other things, prevent clumping of the fiber material in the liquid solution, so that the fiber material can still be formed with good quality at the suction tool. Although clumped fiber material can be drawn in by the suction tool, it would likely result in a molded part with fluctuating layer thickness, which should be avoided in the production of the molded parts if possible. Therefore, the proportion of fiber material in the pulp should be small enough so that clumping or chaining does not occur or only occurs to a negligible extent. The liquid solution can be any solution suitable for the fiber forming process.For example, the pulp can be an aqueous solution containing environmentally friendly, biodegradable fiber material. An aqueous solution is, among other things, easy to handle.

[0011] The fiber forming process refers to the process steps involved in forming the molded part, starting with the provision of the pulp, the forming of the molded part in the suction tool from the fiber material from the pulp, the pre-pressing of the molded part, the hot pressing of the molded part and, if necessary, the coating of the molded part with functional layers, whereby the coating can be arranged at any point in the fiber forming process suitable for the respective layer to be applied.

[0012] The molded parts can have any shape, also referred to here as contour, provided that this shape (or contour) can be produced using the inventive method or that the method is suitable for producing this shape (or contour). The components used for the fiber forming process can be adapted to the respective shape (or contour) of the molded part. For different molded parts with different shapes (or contours), different, appropriately adapted components, such as the suction tool, the suction head, the pre-pressing station, the hot pressing station, etc., can be used. Finished molded parts can represent a wide variety of products, for example, cups, containers, vessels, lids, bowls, portion containers, sleeves, or outer containers for a wide variety of purposes.

[0013] The suction tool, in this context, refers to the tool in which the suction head(s) for forming the molded part are arranged. With a single suction head, the suction head itself is also the suction tool. With multiple suction heads operating simultaneously, they are all arranged within the common suction tool, so that when the suction tool is moved, the individual suction heads within it move in unison. The media supply to the suction tool with multiple suction heads is routed appropriately to the individual suction heads within the tool.

[0014] Placing the suction tool on the pulp refers to contacting the pulp with all suction heads located within the tool, which are designed for forming molded parts. The resulting vacuum draws the fiber material out of the pulp, or, conversely, draws in the pulp containing dissolved fiber material. Partial immersion in the pulp involves not only placing the suction tool on the pulp but also immersing it into the pulp. The immersion depth of the suction tool into the pulp depends on the specific application and fiber forming process and can vary depending on the application and, if applicable, the molded part being formed. Partial immersion of the suction head, or...The suction tool is advantageous because the pulp level in the reservoir could fluctuate due to the movements of the suction head / suction tool, and if the pulp surface is uneven, simple placement could result in locally insufficient suction due to wave-like movements.

[0015] The suction head can have a so-called negative mold. A negative mold is a mold where the suction side of the suction head—that is, the side where the fiber material is deposited due to the suction action of the suction head, thus forming the shape of the part—is located on the inside of the suction head. This means that when the suction head is placed on or immersed in the pulp, this inside surface forms a cavity into which the pulp and fiber material are drawn (as in...). Fig. 2(as shown). In a negative mold, the outer side of the future molded part faces the inner side of the suction head. After molding, the molded part therefore sits on the inside of the suction head.

[0016] Alternatively, the suction head can also have a so-called positive mold. A positive mold is a mold where the suction side of the suction head—that is, the side where the fiber material is deposited due to the suction action of the suction head and thus forms the molded part—is located on the outside of the suction head. This ensures that this outside does not form a cavity after the suction head is placed on or immersed in the pulp (as in...). Fig. 3 (as shown). In a positive mold, the inside of the future molded part faces the outside of the suction head. After forming, the molded part therefore sits on the outside of the suction head.

[0017] The initial shaping of the molded part refers to a first pre-forming stage in which the part is formed from fiber material that was previously randomly distributed in the pulp by adhering to the contour of the suction head. The pre-shaped part still contains a large proportion, for example 70%–80%, of liquid solution, such as water, and is therefore not yet dimensionally stable. Pre-pressing the pre-shaped part significantly reduces the proportion of liquid solution, for example to 55%–65%, so that the contour of the molded part is now considerably more stable. Hot pressing the pre-pressed part with a hot pressing pressure further reduces the proportion of liquid solution, for example to below 10%, preferably to approximately 7%, resulting in the final shape of the molded part, after which it is stable and dimensionally stable.

[0018] The release of the finished molded part refers to the handover of the molded part for further transport or processing, for example to cutting, labeling, printing, and / or packaging stations.

[0019] By combining the forming, pre-pressing, and hot-pressing steps, a molded part is easily produced from a fiber material. Depending on the design of the suction head contour, this part can be flexibly manufactured with a wide variety of contours. The ratio of width or diameter to height of the molded part is not a limiting or critical parameter for the quality of the manufactured parts. The combination of forming, pre-pressing, and hot-pressing steps allows for highly reproducible production of the molded parts with great accuracy and quality regarding the shape and layer thickness of the individual parts. The manufacturing process is capable of processing a wide variety of fiber types, provided they can be dissolved in such a way that excessive clumping of the fibers in the liquid solution is avoided before processing.In particular, stable molded parts can be produced simply, effectively and flexibly from environmentally friendly biodegradable fiber material with good quality and good reproducibility in this way.

[0020] The inventive method thus represents a manufacturing process for environmentally friendly molded parts made from natural fibers and a corresponding machine with which these products (molded parts) can be produced effectively, flexibly and reproducibly with good quality.

[0021] In one embodiment, the pulp contains no organic binder, and preferably no inorganic binder either. Without a binder, the molded parts produced from originally biodegradable fiber material remain biodegradable, since no environmentally harmful binder, or preferably no binder at all, is used. The omission of a binder is made possible by the combination of the forming, pre-pressing, and hot-pressing steps, which together ensure good mechanical bonding of the individual fibers within the fiber material of the molded part. In the process according to the invention, this mechanical bonding is so strong that binders can be omitted to ensure the dimensional stability of the molded part.

[0022] In another embodiment, the environmentally biodegradable fiber material consists essentially of fibers with a fiber length of less than 5 mm. Fibers of this length result, among other things, in a good homogeneous solution of the fiber material in the liquid solution, so that the degree of clumping of the fibers in the pulp is sufficiently low for a good, reproducible fiber forming process for the molded part.

[0023] In a further embodiment, the pulp is provided at a temperature of less than or equal to 80°C, preferably less than or equal to 50°C, and particularly preferably at room temperature. These low temperatures enable, among other things, simple process control, especially at room temperature.

[0024] In another embodiment, the pulp comprises dopants or components that are introduced into the fiber material via the pulp at the beginning of the molding process. Such dopants can be, for example, fragrances, flavorings, active ingredients, minerals, nutritional and conditioning additives, etc., which diffuse out of the fiber material, are leached out, or remain after the environmentally sound degradation of the molded part due to subsequent use and the prevailing conditions.

[0025] In another embodiment, the suction head is fully immersed in the pulp for contact. Complete immersion is particularly suitable for a suction head in a positive mold, since, unlike a negative mold, there is no internal cavity in the suction head where a vacuum can be created between the pulp and the suction surface to draw in the fiber material. To ensure the most uniform possible suction of fiber material, it is advantageous to fully immerse the suction head in the pulp when using a positive mold.

[0026] In another embodiment, the suction head's suction side is formed from a porous sieve. On the pulp-facing side of this sieve, the biodegradable fiber adheres due to the suction action, forming the molded part. The sieve must possess sufficient porosity to allow the pulp, along with the fiber material, to be drawn through it and for the liquid pulp solution to pass through. However, the sieve's porosity must not be too high to prevent the fiber material from adhering to the pulp side.

[0027] In another embodiment, the liquid solution of the pulp passing through the sieve is discharged from the suction tool during the forming process. During forming or suction, the liquid solution content in the formed fiber material is already reduced by approximately 20% to 30% compared to the pulp. This liquid solution passes through the sieve into the suction head. To prevent the suction head from having to temporarily store the liquid solution, it is discharged from the suction head and thus also from the suction tool. The discharged liquid solution can be returned to a pulp processor and reused in the fiber forming process.

[0028] In another embodiment, the suction head includes a collecting ring on its end face facing the pulp for receiving the liquid solution to be removed, to which a discharge channel for the liquid solution is connected. This allows, among other things, the liquid solution that has passed through the sieve to be reliably removed from the suction head and thus from the suction tool, so that this liquid solution does not negatively affect the suction power of the suction head.

[0029] In another embodiment, the suction tool comprises a plurality of suction channels distributed around the screen on the side opposite the pulp side. The plurality of suction channels makes it possible, among other things, to draw in pulp containing fibrous material across the entire surface of the screen, so that the molded part can conform to the screen in a flat, continuous shape.

[0030] In a further embodiment, the suction channels are distributed and arranged around the screen, and the screen structure is designed such that a substantially uniform suction power is present in all areas of the pulp side of the screen. The term "substantially" here refers to a homogeneity of suction power sufficient to achieve a uniformly formed molded part without significant variations in layer thickness at the corners and edges of the molded part, as well as across the surfaces of the molded part. The resulting finished molded part thus exhibits a layer thickness variation of less than 7% relative to the desired layer thickness. In a further embodiment, the suction channels are unevenly distributed beneath the screen, with approximately 50% fewer suction channels per unit area in the area of ​​(negative shapes or inner edges) edges in the molded part. For positive or outer edges, the number of suction channels is reduced. toapproximately 20% increase per unit area. This lower density of suction channels. in the The area of ​​edges (referring here to all corners and edges, recesses and other significant contour changes in the molded part) ensures that material excesses or deficiencies in the area of ​​the edges are avoided relative to other material thicknesses on surfaces without edges.

[0031] In another embodiment, the suction tool is a multi-tool with a multitude of suction heads. With a multi-tool, a large number of molded parts can be formed simultaneously from a common pulp bath, corresponding to the number of suction heads. This increases the throughput of the fiber forming system and thus makes production more economical.

[0032] In another embodiment, the suction head's suction surface is designed either as a negative mold (the inside of the suction head) or as a positive mold (the outside of the suction head). Regarding the terms "negative mold" and "positive mold," please refer to the preceding explanations. Depending on the desired shape or contour of the molded part, either negative or positive molds of the suction head may be advantageous.

[0033] According to the invention, the molded part remains on the suction tool for pre-pressing. Since the molded part is formed during the forming process... in the Since the suction head is still relatively moist and therefore not very dimensionally stable, it is advantageous for a flawless and high-quality process to leave the molded part in the suction head at least until the pre-pressing is completed, in order to avoid potentially damaging tool changes for the molded part.

[0034] According to the invention, the pre-pressing station comprises a pre-pressing lower tool to which the suction tool with an integrated molded part is attached, so that it is positioned between the pre-pressing lower tool and the suction tool, and the suction tool is pressed onto the pre-pressing lower tool with the pre-pressing pressure. The suction tool is designed to exert the pre-pressing pressure on the pre-pressing lower tool. The suction tool can be pressed onto a stationary pre-pressing lower tool, or the pre-pressing lower tool can be pressed onto a stationary suction tool. The term "attached" refers only to the relative movement of the suction tool to the pre-pressing lower tool. During pre-pressing, the suction tool constitutes the pre-pressing upper tool of the pre-pressing station. In one embodiment, the suction tool is placed onto the pre-pressing lower tool and pressed onto it by means of a separate pressing unit, preferably a piston rod.Alternatively, the suction tool can also be attached to a robot arm, which itself applies the pre-compression pressure to the pre-compression lower tool via the suction tool. Analogous to a suction tool as a multi-tool, the pre-compression lower tool can also be designed as a multi-tool in order to apply the pre-compression pressure to all molded parts of the suction tool simultaneously, thus performing the pre-compression for all molded parts at the same time.

[0035] In another embodiment, the suction tool with negative shape as suction head suction surface is placed on the pre-pressing lower tool (with corresponding positive shape) or inserted into the pre-pressing lower tool (as corresponding negative shape) with positive shape as suction head suction surface.

[0036] In another embodiment, the pre-pressing lower tool has a pressing surface facing the molded part that has a lower surface roughness than the screen. This ensures that a homogeneous pressure is exerted on the molded part. Additionally, the adhesion between the pre-pressing lower tool and the molded part is lower than with structured surfaces on the pre-pressing lower tool. This ensures that the pre-pressed molded parts remain in the suction tool and not on the pre-pressing lower tool for transfer to the hot pressing station without any further equipment, which would disrupt the production process. Optionally, the suction tool can generate a suitable vacuum within the suction tool to improve the adhesion of the molded parts to the suction tool during transfer to the hot pressing station.

[0037] In another embodiment, the pre-compression lower tool is made of metal or at least partially of an elastomer, preferably silicone. Metal pre-compression lower tools are particularly suitable for applications where pre-compression requires a temperature above room temperature or a particularly high pre-compression pressure. Pre-compression lower tools made of an elastomer, or at least partially made of an elastomer, are advantageous in multi-tools as both suction tools and pre-compression lower tools, since the elastomer can still be easily deformed under pressure and thus adapts flexibly to a multi-suction tool that may bend under the pre-compression pressure, thereby improving the homogeneity of the forming of the various molded parts in the multi-suction tool. For elevated pre-compression temperatures below 100°C, silicone, for example, is also well-suited as an elastomer, being a temperature-resistant material in this range.

[0038] In another embodiment, the pre-pressing is carried out using a membrane press. Membrane pressing is particularly suitable for geometries of the molded part where pressure needs to be applied over a large area. With a membrane press, even surfaces that are perpendicular to each other in any spatial orientation can be subjected to the same pressure simultaneously, since in membrane pressing the pre-pressing pressure is generated by gas pressure, for example, compressed air, which acts on the membrane regardless of direction. This would not be possible with a piston rod, for example.

[0039] In another embodiment, the pre-pressing lower tool for membrane pressing is designed as a flexible membrane, and the pre-pressing pressure is applied to the membrane as gas pressure, which is then pressed onto the outer contour of the molded part. For this purpose, the membrane is gas-impermeable and flexible so that it can conform to the shape of the molded part under gas pressure. Rubber membranes, for example, can be used. The membrane should have a contour accuracy of less than 20% and can be designed differently in different areas, for example, with thinner and thicker wall thicknesses and / or positioned closer to or further away from the contour.

[0040] In another embodiment, pre-pressing is carried out at a temperature of the pre-pressing station below 80°C, preferably below 50°C, and particularly preferably at room temperature. Pre-pressing reduces the liquid content in the molded part to approximately 55%–65% and pre-hardens the part sufficiently to ensure adequate dimensional stability for tool transfer. An excessively high temperature would reduce the liquid content in the molded part too much, making the material too stiff for subsequent hot pressing. The combination of pre-pressing and hot pressing enables the reproducible production of high-quality molded parts with a low reject rate.

[0041] In a further embodiment, pre-pressing is carried out at a pre-pressing pressure between 0.2 N / mm² and 0.3 N / mm², preferably between 0.23 N / mm² and 0.27 N / mm². These moderate pressures, which are lower than the hot pressing pressure, allow for gentle solidification of the molded part with moderate liquid reduction, which is advantageous for a low-reject hot pressing process.

[0042] According to the invention, the process, after pre-pressing, comprises the step of transferring the pre-pressed part to the hot pressing station using the suction tool, whereby the part is removed from the suction tool for subsequent hot pressing. This transfer is advantageous because hot pressing is carried out at high temperature and significantly higher pressure. If the part were to remain in the suction tool without being transferred for hot pressing, the fiber material could become entangled in the suction tool's screen and be difficult, or even impossible, to remove after hot pressing, potentially resulting in damage. Furthermore, the high pressure could damage the screen, rendering the suction tool unusable. The transfer can be accomplished by passively depositing the part(s) from the suction tool or actively transferring them to the hot pressing station by means of an ejection pressure applied within the suction tool against the parts.

[0043] In a further embodiment, the hot pressing station comprises a hot pressing lower tool with a hot pressing side adapted to the contour of the molded part and a correspondingly shaped hot pressing upper tool. During transfer, the molded part is placed onto or inserted into the hot pressing lower tool by the suction tool, and during hot pressing, the hot pressing upper tool is pressed onto the hot pressing lower tool with the molded part positioned between them. Depending on whether the suction heads of the suction tool have a negative or positive form, the molded part is placed onto the hot pressing lower tool (negative form) or inserted (positive form). In this respect, the hot pressing side is the outside of the hot pressing lower tool in the case of a negative form, and the inside in the case of a positive form. The hot pressing upper tool is shaped accordingly, complementarily in each case.The two hot-pressing upper and lower tools can work together to apply high pressures and high temperatures to the molded part between them. In a further embodiment, at least the hot-pressing lower tool is made of metal.

[0044] In another embodiment, the hot-pressing lower tool includes channels on its outer surface, through which the liquid solution can be at least partially drained away during hot pressing. The reduction of the liquid (or moisture) in the molded part from approximately 55%–60% to less than 10% releases a quantity of liquid, which, due to the high temperatures during hot pressing, at least partially evaporates. This vapor is therefore drained away via the channels to prevent damage to the molded part, including damage caused by the vapor.

[0045] In another embodiment, the hot pressing upper tool is adapted to the contour of the molded part at least with the side facing the molded part; preferably, the hot pressing upper tool is made of metal.

[0046] In another embodiment, the lower and upper hot-press dies have different temperatures during hot pressing; preferably, the upper hot-press die has a higher temperature than the lower hot-press die. This results in, among other things, a better surface finish on the molded part, particularly on the warmer side. In a further embodiment, the temperatures differ by at least 25°C, preferably not more than 60°C, and most preferably by 50°C.

[0047] In another embodiment, hot pressing is carried out at a temperature above 150°C, preferably between 180°C and 250°C. This allows a reduction of the liquid (or moisture) in the molded part to below 10%.

[0048] In a further embodiment, hot pressing is carried out at a hot pressing pressure higher than the pre-pressing pressure. This allows a reduction of the liquid (or moisture) in the molded part to below 10%, particularly in combination with the temperatures mentioned above. In a further embodiment, the hot pressing pressure is applied between 0.5 N / mm² and 1.5 N / mm², preferably between 0.8 N / mm² and 1.2 N / mm².

[0049] In a further embodiment, the hot pressing pressure is applied for a pressing time of less than 20 s, preferably more than 8 s, particularly preferably between 10 and 14 s, and even more preferably 12 s. This allows a reduction of the liquid (or moisture) in the molded part to below 10%, especially in combination with the temperatures and hot pressing pressures mentioned above.

[0050] In another embodiment, the contour of the molded part is designed such that all surfaces of the molded part have an angle α of at least 3 degrees to the pressing direction during hot pressing. This ensures that the hot pressing pressure can be applied to all surfaces of the molded part. No pressure can be exerted on surfaces parallel to the pressing direction during hot pressing. The hot pressing pressure is applied hydraulically to the hot pressing station, for example, via a piston rod, whereby this piston rod presses, for example, on the upper hot pressing tool, which in turn presses on the stationary lower hot pressing tool, with the molded part in between. The arrangement could also be reversed.

[0051] In another embodiment, the finished molded part is then output to further processing stations of the fiber forming plant, for example for further transport or further processing, for example in a cutting, marking, printing, and / or packaging station.

[0052] In a further embodiment, the method comprises the additional step of coating the molded part, preferably the finished molded part, with one or more functional layers. Such functional layers can include, among other things, additional functionalities such as moisture, aroma, odor, or taste barriers.

[0053] The invention further relates to a fiber forming plant for the production of molded parts from environmentally biodegradable fiber material using the inventive method comprising A reservoir for providing a pulp as a liquid solution with biodegradable fiber material; a suction tool attached to a movement unit with a suction head having a three-dimensionally shaped suction head suction side, the shape of which is adapted to a contour of the subsequent molded part, wherein the movement unit is designed to contact the suction tool with the pulp by placing it on or at least partially immersing it in the pulp; wherein the suction tool is designed to mold the part by drawing the biodegradable fiber material onto the suction head suction side using negative pressure in the suction tool; a pre-compression station for pre-compressing the molded part with a pre-compression pressure to reduce the proportion of the liquid solution in the molded part;and a hot pressing station for hot pressing the pre-molded part with a hot pressing pressure for final shaping of the part and for further reducing the proportion of liquid solution in the part; and an output unit for dispensing the final molded part.

[0054] The output unit then ejects the molded part for further transport or processing, for example to subsequent cutting, labeling, printing, and / or packing stations.

[0055] By combining pulp forming with a suction tool, pre-pressing with a pre-pressing station, hot pressing with a hot pressing station, and subsequent output of the molded part using the aforementioned fiber forming system, a molded part can be easily produced from a fiber material. Depending on the design of the suction head contour, this part can be flexibly manufactured with a wide variety of contours. The ratio of width or diameter to height of the molded part is not a limiting or critical parameter for the quality of the respective parts. By combining the suction tool for forming with the pre-pressing and hot pressing stations, the molded parts can be produced with high reproducibility and accuracy, as well as with high quality in terms of shape and layer thickness of the individual molded part sections.The fiber forming system according to the invention is capable of processing fibers of various types, provided that these can be dissolved in such a way that excessive clumping of the fibers in the liquid solution prior to processing is avoided. In particular, stable molded parts can be produced simply, effectively, and flexibly from environmentally biodegradable fiber material with good quality and reproducibility.

[0056] The fiber forming system according to the invention thus makes it possible to produce environmentally friendly molded parts from natural fibers effectively, flexibly and reproducibly with good quality.

[0057] In one embodiment, the fiber forming system includes a control unit for controlling the process. The control unit can be implemented as a processor, a separate computer system, or web-based, and is suitably connected to the components of the fiber forming system to be controlled, for example, via data cables or wirelessly using WLAN, radio, or other wireless transmission methods.

[0058] In a further embodiment, the fiber forming system additionally includes a coating unit for applying one or more functional layers to the molded part. These functional layers can be used to impart additional properties such as moisture, aroma, odor, or taste barriers. The coating unit can be positioned at any suitable location in the process sequence for manufacturing the molded part. Depending on the application, the functional layer can be applied during the suction process, after pre-pressing, or after hot pressing. The term "functional layer" here refers to any additional layer applied to the original fiber material, whether applied to the entire surface or to specific areas of the molded part, both on the inside and / or outside.

[0059] The invention further relates to a molded part made of environmentally biodegradable fiber material produced using the inventive method or the inventive fiber molding system.

[0060] In one embodiment, the molded part has a contour in which all surfaces of the molded part form an angle of at least 3 degrees to a pressing direction during hot pressing. With such a molded part, a minimum required hot pressing pressure can be applied to all surfaces in order to, among other things, reduce the liquid solvent content in the fiber material sufficiently to ensure the molded part's dimensional stability.

[0061] In another embodiment, the biodegradable fiber material comprises no organic binder, and preferably also no inorganic binder. This results in particularly good biodegradability of the molded part.

[0062] In another embodiment, the biodegradable fiber material consists essentially of fibers with a fiber length of less than 5 mm. This allows for the production of a higher-quality molded part. Furthermore, shorter fibers reduce the surface roughness and porosity of the molded part, making it easier to apply any coatings.

[0063] In another embodiment, one or more functional layers are applied to the environmentally biodegradable fiber material of the molded part. Such functional layers can possess, among other things, additional functionalities such as moisture, water, aroma, odor, or taste barriers, or barriers against fats, oils, gases such as O₂ and N₂, weak acids, all substances that contribute to the spoilage of food, and / or non-food-grade substances.

[0064] In a further embodiment, the fiber material of the molded part comprises dopants or components that, due to their concentration, the application of the molded part, or environmental conditions, are released from the fiber material of the molded part in a desired manner to exert an effect that supports the application of the molded part. These dopants or components may already be present in the pulp and be incorporated into the molded part during the fiber forming process. Such dopants can be, for example, fragrances, flavorings, active ingredients, minerals, nutritional and conditioning additives, etc.

[0065] It should be expressly noted that, for the sake of readability, expressions like "at least" have been avoided wherever possible. Instead, an indefinite article ("one", "two", etc.) should normally be understood as "at least one, at least two, etc." unless the context makes it clear that "exactly" the specified number is meant.

[0066] It should also be noted here that, within the context of the present patent application, the term "in particular" is always to be understood as introducing an optional, preferred feature. The term is therefore not to be understood as "namely" or "namely".

[0067] It is understood that features of the solutions described above or in the claims can also be combined, if necessary, in order to implement the advantages and effects achievable here in a cumulative manner. Brief description of the characters

[0068] Further features, effects, and advantages of the present invention are explained with reference to the accompanying drawing and the following description. Components that are at least substantially identical in their function in the individual figures are identified by the same reference numerals, although the components need not be numbered and described in all figures.

[0069] The drawing shows: Fig. 1: Schematic representation of an embodiment of the method according to the invention; Fig. 2: An embodiment of the suction head with negative mold for the contacting and forming steps as well as the transfer to pre-pressing in the method according to the invention; Fig. 3: An embodiment of the suction head with positive mold for the contacting and forming steps as well as the transfer to pre-pressing in the method according to the invention; Fig. 4: An embodiment of the pre-pressing station in a side section of the fiber forming system according to the invention; Fig. 5: Another embodiment of the pre-pressing station in a side section with a membrane as a pre-pressing lower tool of the fiber forming system according to the invention; Fig. 6: An embodiment of the hot pressing station in a side section of the fiber forming system according to the invention; Fig. 7: An example of a molded part made of environmentally biodegradable fiber material produced using the methods according to the invention on a fiber forming system according to the invention; Fig.Fig. 8: a further embodiment of the pre-pressing station with motion unit and pulp preparation and supply unit of the fiber forming plant according to the invention; Fig. 9: an embodiment of the fiber forming plant according to the invention; and Fig. 10: a further embodiment of the fiber forming plant according to the invention. Examples of implementation

[0070] Fig. 1Figure 1 shows a schematic representation of an embodiment of the inventive method 100 for producing molded parts 10 from environmentally biodegradable fiber material 11 by means of a fiber forming process in a fiber forming plant 20, comprising the following steps. To start the method, a pulp 1 is provided as a liquid solution containing environmentally biodegradable fiber material 11 110, so that a suction tool 2 can contact the pulp 1 by placing it on top of or at least partially immersing it 120. The suction tool 2 comprises a suction head 21 with a three-dimensionally shaped suction head suction side 21i, the shape of which is adapted to a contour of the subsequent molded part 10. This is followed by the forming 130 of the molded part 10 by drawing the environmentally biodegradable fiber material 11 onto the suction head suction side 21i by means of a vacuum in the suction tool 2.The suction tool can contain a single suction head or be a multi-tool with a multitude of suction heads. A suction tool with two or more suction heads 21 is referred to as a multi-tool. In other embodiments, the multi-tool can also comprise 10, 20, 30, or more suction heads 21. The subsequent pre-compression 140 of the molded part 10 takes place in a pre-compression station 3 with a pre-compression pressure VD to reduce the proportion of liquid solution in the molded part 10. The pre-compression station is adapted to the suction tool, possibly in the form of a multi-tool. After pre-compression 140, the pre-compressed molded part 10 can be transferred 170 by means of the suction tool 2 to the hot pressing station 4, whereby the molded part 10 is removed from the suction tool 2 for subsequent hot pressing 150.The hot pressing station 4 comprises a hot pressing lower tool 41 with a hot pressing side 41a adapted to a contour 10i of the molded part 10 and a hot pressing upper tool 42. During transfer 170, the molded part 10 is placed onto or inserted from the suction tool 2 onto the hot pressing lower tool 41. During hot pressing 150, the hot pressing upper tool 42 is pressed onto the hot pressing lower tool 41 with the molded part 10 positioned between them. During hot pressing 150 of the pre-pressed molded part 10 with a hot pressing pressure HD, the final forming of the molded part 10 takes place, resulting in a further reduction of the proportion of liquid solution in the molded part 10 in the corresponding hot pressing station 4. The process can also include the additional step of coating 180 of the molded part 10, preferably the final formed part 10, with one or more functional layers 15.At the end of the process, the finished molded part 10 is output to further processing stations of the fiber forming plant 20 160.

[0071] Fig. 2Figure 1 shows an embodiment of the suction head 21 with a negative mold for the contacting steps 120 and forming steps 130, as well as the transfer of the molded part 10 to pre-pressing 140 in the inventive method 100. The suction head 21 shown here can be the only suction head 21 in the suction tool 2 or part of a multi-tool with a plurality of suction heads 21, whereby for the sake of clarity only one suction head 21 is shown here as an example. The pulp reservoir 30 for the manufacturing process is shown schematically below the suction head 21 with the fiber material 11 indicated as "waves". In the method 100, a pulp 1 with a proportion of environmentally compatible biodegradable fiber material 11 of less than 5%, preferably less than 2%, particularly preferably between 0.5% and 1.0%, in a liquid solution, for example an aqueous solution, can be used. Advantageously, the pulp 1 does not contain any organic binder, preferably no binder at all.The environmentally biodegradable fiber material 11 can consist essentially of fibers with a fiber length of less than 5 mm. The pulp 1 is provided at a temperature of less than or equal to 80°C, preferably less than or equal to 50°C, and particularly preferably at room temperature. The suction head suction side 21i of the suction head 21 is formed from a porous screen 22, on the pulp side 22p of which, facing the pulp 1, the environmentally biodegradable fiber 11 adheres due to the suction for forming 130 of the molded part 10 (see molded part 10 in ). Fig. 2cFurthermore, the suction tool 2 comprises a plurality of suction channels 23 distributed around the sieve 22 on its side 22s opposite the pulp side 22p for drawing in the pulp 1. The suction channels 23 are distributed and arranged around the sieve 22, and the structure (surface shape, sieve size, pore size) of the sieve 22 is designed such that a substantially uniform suction performance is present in all areas of the pulp side 22p of the sieve 22. For this purpose, the suction channels 23 have, for example, an uneven distribution beneath the sieve 23, with fewer suction channels 23 per unit area in the region of edges in the molded part 10. As in Fig.2bAs shown, the suction head for molding the part is only slightly immersed in the pulp 1 so that a closed cavity is formed in the interior 21i of the suction head. In other embodiments, the suction head 21 could also be fully immersed in the pulp 1. The liquid solution of the pulp 1 passing through the sieve 22 during the molding process 130 is discharged from the suction tool 2. For this purpose, the suction head 21 has a collecting ring 24 on its end face 21p facing the pulp 1 to receive the liquid solution to be discharged, to which a discharge channel 25 for the liquid solution is connected. As shown in Fig. 2c As shown, the molded part 10 (grey inner layer in the suction head 21) is then placed on the pre-pressing lower tool 31 with a pressing surface 31a as the outer surface of the pre-pressing lower tool 31 for pre-pressing.

[0072] Fig. 3Figure 1 shows an embodiment of the suction head 21 with a positive mold for the contacting steps 120 and forming steps 130, as well as the transfer to pre-pressing 140 in the inventive method 100. The suction head 21 shown here can be the only suction head 21 in the suction tool 2 or part of a multi-tool with a plurality of suction heads 21, whereby only one suction head 21 is shown here as an example for the sake of clarity. Regarding the pulp reservoir 30 and the properties of the pulp 1, the same applies here as already described for [reference to previous figure]. Fig. 2 described. The suction head suction surface 21p is different here in contrast to Fig. 2 It is executed as a positive form and forms the outer surface 21a of the suction head. Regarding the construction of the suction head 21 with sieve 22 and suction channels 23, this already applies under Fig. 2 described. To aspirate the pulp 1 with fiber material 11, the suction head 21 is fully immersed in the pulp 1 for contact 120 in the positive form of the suction head suction surface 21p. As described in Fig. 3cAs shown, the molded part 10 (grey outer layer on the suction head 21) is then inserted into the pre-pressing lower tool 31 for pre-pressing, which has a shape adapted to the positive shape of the suction head 21 with a pressing surface 31 as the inner surface of the pre-pressing lower tool 31.

[0073] Fig. 4Figure 1 shows an embodiment of the pre-pressing station 3 in a side section of the fiber forming system 20 according to the invention. For pre-pressing 140, the molded part 10 remains in the suction tool 2, which thus assumes the function of the pre-pressing upper tool. The suction tool 2 is shown here as a suction head 21 with a negative mold. The pre-pressing station 3 comprises a pre-pressing lower tool 31, onto which the suction tool 2 with the molded part 10 is placed, so that it is arranged between the pre-pressing lower tool 31 and the suction tool 2, so that the suction tool 2 can be pressed onto the pre-pressing lower tool 31 with the pre-pressing pressure VD, thus removing moisture from the molded part and stabilizing the fiber material by pre-pressing. Here, the pre-pressing lower tool 31 has a pressing surface 31a facing the molded part 10, which has a lower surface roughness than the screen 22.The pre-pressing lower tool 31 can be made of metal or at least partially of an elastomer, for example silicone, the latter being advantageous for suction tools designed as multi-tools. The pre-pressing 140 is carried out at a temperature of the pre-pressing station 3 below 80°C, preferably below 50°C, and particularly preferably at room temperature, wherein the pre-pressing pressure VD is between 0.2 N / mm² and 0.3 N / mm², preferably between 0.23 N / mm² and 0.27 N / mm².

[0074] Fig. 5Figure 1 shows a further embodiment of the pre-pressing station 3 in a side section with a membrane 32 as the pre-pressing lower tool 31 of the fiber forming system 20 according to the invention for carrying out the pre-pressing 140 as membrane pressing. The suction tool 2 is inserted here with a positive mold as a suction head suction surface 21s into the correspondingly shaped pre-pressing lower tool 31. For the membrane pressing 150, the membrane 32 is designed as a flexible membrane 32. The pre-pressing pressure VD is applied to the membrane 32 as gas pressure, which is then pressed onto the outer contour 10a of the molded part 10. This allows pressure to be exerted on surfaces of the molded part 10 that cannot be applied using hydraulic pressing, since the gas pressure applies the membrane to all surfaces with the same pressure, regardless of direction.

[0075] Fig. 6Figure 1 shows an embodiment of the hot pressing station 4 in a side section of the fiber forming system 20 according to the invention. After pre-pressing 140, the pre-pressed part 10 is transferred to the hot pressing station 4 170 by means of the suction tool 2, whereby the part 10 is removed from the suction tool 2 for subsequent hot pressing 150. The hot pressing station 4 comprises a hot pressing lower tool 41 with a hot pressing side 41a adapted to a contour 10i of the part 10 and a hot pressing upper tool 42, wherein during transfer 170 the part 10 is placed onto or inserted from the suction tool 2 onto the hot pressing lower tool 41 (depending on whether a negative mold is present, as here, or a positive mold is used). During hot pressing 150, the hot pressing upper tool 42 is then pressed onto the hot pressing lower tool 41 with the part 10 arranged between them. The hot pressing lower tool 41 can be made of metal.The hot-pressing lower tool 41 also includes channels 41k to its hot-pressing side 41a, through which the liquid solution can be at least partially discharged during hot pressing 150. The hot-pressing upper tool 42 is adapted to the contour 10a of the molded part 10, at least with its side 42i facing the molded part; preferably, the hot-pressing upper tool 42 is also made of metal. Different temperatures can be applied to the hot-pressing lower tool 41 and the hot-pressing upper tool 42 during hot pressing; preferably, the hot-pressing upper tool 42 has a higher temperature than the hot-pressing lower tool 41, with the temperatures differing by at least 25°C, preferably not more than 60°C, and particularly preferably by 50°C. Hot pressing can be carried out at a temperature greater than 150°C, preferably between 180°C and 250°C. In this process, hot pressing is carried out at a hot pressing pressure HD higher than the pre-pressing pressure VD.The hot pressing pressure HD can be between 0.5 N / mm² and 1.5 N / mm², preferably between 0.8 N / mm² and 1.2 N / mm², and is applied for a pressing time of less than 20 s, preferably more than 8 s, particularly preferably between 10 and 14 s, and even more preferably between 12 s. Fig. 7Figure 1 shows an example of a molded part 10 made of biodegradable fiber material 11, produced using the methods 100 according to the invention on a fiber molding machine 20 according to the invention. The molded part 10 is very dimensionally stable and has a liquid content in the fiber material 11 of less than 8%. The molded part is biodegradable. The contour of the molded part 10 is designed such that all surfaces 10f of the molded part 10 have an angle α of at least 3 degrees to the pressing direction PR during hot pressing 150. The biodegradable fiber material 11 does not include an organic binder, and preferably also no inorganic binder. It consists essentially of fibers with a fiber length of less than 5 mm. One or more functional layers 15 can be applied to the molded part 10.In a further embodiment, the fiber material 11 of the molded part 10 can also contain dopants or components that, due to their concentration, application of the molded part 10, and / or environmental conditions, dissolve from the fiber material 11 of the molded part 11 in a desired manner to exert an effect that supports the application of the molded part 11. These dopants or components can be introduced into the fiber material via the pulp at the beginning of the molding process or be part of a subsequent coating with a functional layer, provided that the fiber molding process does not permit earlier addition. Such dopants can be, for example, fragrances, flavorings, active ingredients, minerals, nutritional and conditioning additives, etc., which diffuse out of the fiber material due to subsequent use and the prevailing conditions, are dissolved, or remain after the environmentally sound degradation of the molded part.The environmental conditions that promote this process can include, for example, differences in the concentration of certain materials, temperature, humidity, and / or light exposure. Supportive measures could include, for example, the care, flavor modification, maintenance, etc., of the molded part 10 or of the goods transported with or in the molded part 10, or at least temporarily stored therein.

[0076] Fig. 8 Figure 1 shows a further embodiment of the pre-compression station 3 with pulp reservoir 30, motion unit 40 and pulp preparation and supply unit 35 of the fiber forming plant 20 according to the invention. The suction tool 2 shown here is a multi-tool with 20 suction heads 21. Accordingly, the pre-compression lower tool 31 also comprises 20 pre-compression units on the pre-compression lower tool 31 as a multi-tool.

[0077] Fig. 9Figure 1 shows an embodiment of the fiber forming plant 20 according to the invention for the production of molded parts 10 from environmentally biodegradable fiber material 11 using the method 100 according to the invention as shown in Figure 20. Fig. 1The illustration comprises a reservoir 30 for providing 110 a pulp 1 as a liquid solution with environmentally biodegradable fiber material 11, a suction tool 2 attached to a motion unit 40 with a suction head 21 having a three-dimensionally shaped suction head suction side 21i, the shape of which is adapted to a contour of the subsequent molded part 10, wherein the motion unit 30 is designed to contact the suction tool 2 with the pulp 1 by placing it on or at least partially immersing it 120. The motion unit 40 is implemented here as a robot. A robot can perform precise and reproducible movements in confined spaces and is therefore particularly suitable for guiding the suction tool between the pulp reservoir 30 and the pre-compression station 3.The suction tool 2 is designed to form the molded part 10 by drawing in the environmentally biodegradable fiber material 11 onto the suction head suction side 21i using a vacuum in the suction tool 2. The pre-compression station 3 is designed to pre-compress 140 the formed molded part 10 with a pre-compression pressure VD to reduce the proportion of liquid solution in the molded part 10 and to stabilize its shape. The hot-compression station 4 is designed to hot-compress 150 the pre-compressed molded part 10 with a hot-compression pressure HD, thus finalizing the molded part 10 and further reducing the proportion of liquid solution in the molded part 10. The output unit 50 then outputs the final molded part 10. To control the process, the fiber molding system 20 includes a control unit 60, which is appropriately connected to the other components of the fiber molding system 20 to control these components.

[0078] Fig. 10Figure 1 shows a further embodiment of the fiber forming plant 20 according to the invention, wherein the provision of the pulp 1 and the pre-pressing in the pre-pressing station 3 are carried out as already described in Figure 2. Fig. 9The process is shown. After pre-pressing, in this embodiment, two separate system sections are operated, each comprising a hot pressing station 4, a coating unit 70 for applying one or more functional layers to the molded part 10, a printing unit 80 for printing on the molded part, and a stacking unit 90 for stacking the finished molded parts 10. The molded parts are transported between these stations on a conveyor belt 95. Optionally, the fiber forming machine could also include a cutting unit for post-processing or for separating the molded parts. The division into two sub-systems after pre-pressing is possible because the hot pressing process is significantly slower than the forming 130 and pre-pressing 140, both of which can be carried out approximately five times or more faster than the hot pressing 150.Therefore, the pre-pressing station can supply at least two sub-systems for the subsequent steps without causing any time loss in hot pressing 150.

[0079] It should be explicitly noted at this point that features of the solutions described above or in the claims and / or figures can also be combined, if necessary, in order to implement or achieve the explained features, effects and advantages in a cumulative manner.

[0080] It is understood that the embodiment described above is merely a first embodiment of the present invention. Therefore, the embodiment of the invention is not limited to this embodiment. List of reference symbols used

[0081] 1 Pulp 11 Environmentally friendly biodegradable fiber material 2 Suction tool 21 Suction head 21a Suction head outer side 21i Suction head inner side 21p End face of the suction head facing the pulp 21s Suction head suction side 22 Porous sieve 22p Side of the sieve facing the pulp (pulp side) 22s Side of the sieve opposite the pulp side (suction head side) 23 Suction channels 24 Collecting ring 25 Discharge channel for the liquid solution 3 Pre-compression station 31 Pre-compression lower tool 31a Pressing surface of the pre-compression lower tool 32 Membrane as pre-compression lower tool 4 Hot pressing station 41 Hot pressing lower tool of the hot pressing station 41a Hot pressing side of the hot pressing lower tool, e.g. outer side 41k Channels in the hot pressing lower tool 42 Hot pressing upper tool the hot press station 42idem mold part facing side (inside) of the hot press upper tool 10 Molded part made of environmentally friendly biodegradable fiber material 10i Inner contour (inside) of the molded part 10a Outer contour (outside) of the molded part 10f Surface area of ​​the molded part 15 Functional layer (one or more) 20 Fiber forming system 30 Pulp reservoir 35 Pulp preparation and supply unit 40 Motion unit 50 Dispensing unit 60 Control unit 70 Coating unit 80 Printing unit 90 Stacking unit 95 Conveyor belt 100 Process for manufacturing molded parts from environmentally friendly biodegradable fiber material 110 Providing pulp 120 Contacting a suction tool with the pulp 130 Forming the molded part by suction of the environmentally friendly biodegradable fiber material 140 Pre-pressing the formed molded part in a pre-pressing station 150 Hot pressing of the pre-pressed molded part, e.g., membrane presses 160 Dispensing the finished molded part 170 Transferring the pre-pressed molded part to the hot pressing station 180 Coating the molded part with one or more functional layers HD Hot pressing pressure PR Pressing direction VD Pre-pressing pressure

Claims

1. A method (100) for producing molded parts (10) from sustainable, degradable fiber material (11) by means of a fiber molding process in a fiber molding machine (20) comprising the following steps: - Provision of (110) a pulp (1) as a liquid solution comprising sustainable, degradable fiber material (11); - Contact (120) of a suction tool (2) with the pulp (1) by placing it on or at least partially immersing it in the pulp (1), wherein the suction tool (2) comprises a suction head (21) having a three-dimensionally shaped suction head suction side (21i), the shape of which is adapted to a contour of the subsequent molded part (10); - Molding (130) of the molded part (10) by suctioning the sustainable, degradable fiber material (11) onto the suction head suction side (21i) by means of negative pressure in the suction tool (2); - Pre-pressing (140) of the pre-molded part (10) in a pre-pressing station (3) having a pre-pressing pressure (VD) for reducing a proportion of the liquid solution in the molded part (10), wherein the molded part (10) remains on the suction tool (2) for pre-pressing and the pre-pressing station (3) comprises a lower pre-pressing tool (31) to which the suction tool (2) is attached with the molded part (10) molded thereon, so that it is arranged between the lower pre-pressing tool (31) and the suction tool (2) and the suction tool (2) is pressed onto the lower pre-pressing tool (31) via the pre-pressing pressure (VD); - Transfer (170) of the pre-pressed molded part (10) to a hot-pressing station (4) by means of the suction tool (2) after pre-pressing has been completed, whereby the molded part (10) is removed from the suction tool (2) for subsequent hot pressing (150); - Hot pressing (150) of the pre-pressed molded part (10) via a hot-pressing pressure (HD) for final molding of the molded part (10) and for further reduction of the proportion of liquid solution in the molded part (10) in the hot-pressing station (4); and - Release (160) of the final molded part (10).

2. The method (100) according to claim 1, wherein the suction head suction side (21i) of the suction head (21) is constructed from a porous filter (22), on whose pulp side (22p) facing the pulp (1) the sustainable, degradable fiber (11) adheres due to the suction for molding (130) the molded part (10).

3. The method (100) according to claim 2, wherein the liquid solution comprising the pulp (1) passing through the filter (22) is discharged from the suction tool (2) during molding (130) and the suction head (21) comprises a collecting ring (24) on its end face (21p) facing the pulp (1) for receiving the liquid solution to be discharged, to which collecting ring a discharge channel (25) for the liquid solution is connected.

4. The method (100) according to any of the preceding claims, wherein the lower pre-pressing tool (31) is fabricated from metal or at least partly from an elastomer, preferably silicone.

5. The method (100) according to any of the preceding claims, wherein pre-pressing (140) is carried out as membrane pressing, wherein, for the membrane pressing (150), the lower pre-pressing tool (31) is designed as a flexible membrane (32) and the pre-pressing pressure (VD) is applied as gas pressure to the membrane (32), which is then pressed onto the outer contour (10a) of the molded part (10).

6. The method (100) according to any of the preceding claims, wherein pre-pressing (140) is carried out at a temperature of the pre-pressing station (3) of less than 80°C, preferably less than 50°C, particularly preferably at room temperature.

7. The method (100) according to any of the preceding claims, wherein pre-pressing (140) is carried out at the pre-pressing pressure (VD) between 0.2 N / mm2 and 0.3 N / mm2, preferably between 0.23 N / mm2 and 0.27 N / mm2.

8. The method (100) according to any of the preceding claims, wherein the hot-pressing station (4) comprises a lower hot-pressing tool (41) having a hot-pressing side (41a) adapted to a contour (10i) of the molded part (10) and an upper hot-pressing tool (42), wherein, during transfer (170), the molded part (10) is mounted or inserted from the suction tool (2) onto the lower hot-pressing tool (41) and, during hot pressing (150), the upper hot-pressing tool (42) is pressed onto the lower hot-pressing tool (41) having the molded part (10) arranged therebetween.

9. The method (100) according to claim 8, wherein the lower hot-pressing tool (41) and the upper hot-pressing tool (42) have different temperatures during hot pressing, preferably the upper hot-pressing tool (42) having a higher temperature than the lower hot-pressing tool (41).

10. The method (100) according to any of the preceding claims, wherein hot pressing is carried out at a temperature greater than 150°C, preferably between 180°C and 250°C.

11. The method (100) according to any of the preceding claims, wherein hot pressing (140) is performed at the hot-pressing pressure (HD) higher than the pre-pressing pressure (VD).

12. The method (100) according to claim 11, wherein the hot-pressing pressure (HD) is carried out between 0.5 N / mm2 and 1.5 N / mm2, preferably between 0.8 N / mm2 and 1.2 N / mm2.

13. The method (100) according to any of the preceding claims, wherein the hot-pressing pressure (HD) is applied for a pressing time of less than 20s, preferably of more than 8s, particularly preferably between 10 and 14s, even more preferably of 12s.

14. The method (100) according to any of the preceding claims, comprising the additional step of coating (180) the molded part (10), preferably the final molded part (10), with a or a plurality of functional layers (15).

15. A fiber molding machine (20) for producing molded parts (10) from sustainable, degradable fiber material (11) by means of a process (100) according to any of the preceding claims, comprising - A reservoir (30) for providing (110) a pulp (1) as a liquid solution comprising sustainable, degradable fiber material (11); - A suction tool (2) attached to a motion unit (40) and having a suction head (21) with a three-dimensionally shaped suction head suction side (21i), the shape of which is adapted to a contour of the subsequent molded part (10), wherein the motion unit (30) is configured to contact (120) the suction tool (2) having the pulp (1) by placing it on or at least partially immersing it in the pulp (1); - wherein the suction tool is configured to mold (130) the molded part (10) by suctioning the sustainable, degradable fiber material (11) onto the suction head suction side (21i) by means of negative pressure in the suction tool (2); - a pre-pressing station (3) for pre-pressing (140) the molded part (10) via a pre-pressing pressure (VD) for reducing a portion of the liquid solution in the molded part (10); and - a hot-pressing station (4) for hot pressing (150) the pre-molded part (10) via a hot-pressing pressure (HD) for final molding of the molded part (10) and for further reduction of the proportion of liquid solution in the molded part (10); and - a release unit (50) for releasing (160) the final molded part (10).

16. The fiber molding machine (20) according to claim 15, characterized in that the fiber molding machine (20) comprises a control unit (60) for controlling the executed process.

17. The fiber forming machine (20) according to claim 15 or 16, characterized in that the fiber molding machine (20) also comprises a coating unit (70) for applying a or a plurality of functional layers to the molded part (10).

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