Patent Application
20240368843
The invention relates to a method for manufacturing molded parts from biodegradable fiber material by means of a fiber molding process in a fiber molding system, such a fiber molding system for carrying out the above-mentioned method, and a molded part produced by means of such a fiber molding system or by means of such a method.
It is desirable to protect citizens and the environment from plastic pollution. In particular, single-use plastic products such as packaging materials or plastic cutlery and plastic tableware cause large amounts of waste. In this respect, there is an increasing demand for substitute materials for plastic packaging materials and containers which allow these products to be manufactured from recyclable plastics, materials with a lower plastic proportion, or even from plastic-free materials.
The concept 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 in this case, as in most fiber-processing methods, is pulp. In principle, pulp consists of water, natural fibers, and a binding agent such as industrial starch (potato starch) and has a mushy consistency.
Since consumers are interested in a wide variety of environmentally friendly products of different sizes, shapes, and requirements and do not necessarily demand said products in very large quantities, it would be desirable to have available a manufacturing method for environmentally friendly molded parts made from natural fibers and to have available a corresponding machine in order to reproducibly manufacture said products (molded parts) effectively, flexibly, and with a high level of quality.
The object of the invention is that of providing a manufacturing method for environmentally friendly molded parts made from natural fibers and a corresponding machine by means of which said products (molded parts) can be reproducibly manufactured effectively, flexibly, and with a good level of quality.
The object of the invention is achieved by a method for manufacturing molded parts from biodegradable fiber material by means of a fiber molding process in a fiber molding system, comprising the following steps:
The term “biodegradable fiber material” refers to fiber materials that can decompose under environmental influences such as moisture, temperature, and/or light, wherein the decomposition process takes place over a short period of time, for example in the range of days, weeks, or a few months. For the sake of simplicity, the “biodegradable fiber material” is subsequently sometimes referred to as simply “fiber material.” Preferably, neither the fiber material nor the decomposition products should pose an environmental hazard or contamination in this case. Fiber materials that are a biodegradable fiber material within the meaning of the present invention are, for example, natural fibers obtained from cellulose, paper, cardboard, wood, grass, plant fibers, sugar cane residue, hemp, etc., or from their components or parts thereof and/or appropriately recycled material. However, a biodegradable fiber material can also refer to artificially manufactured fibers such as PLA (polylactide), etc., which correspond to the above-mentioned fiber materials or share their properties. The biodegradable fiber material is preferably compostable. The biodegradable fiber material and the containers made thereof are preferably suitable for introduction into the material cycle of the German organic waste bin and as a resource for biogas systems. The fiber materials and the containers made thereof are preferably biodegradable in accordance with EU standard EN 13432.
The term “pulp” refers to fluid masses that contain fibers, namely the biodegradable fiber material. The term “liquid” in this case refers to the state of aggregation of the pulp, wherein the liquid pulp comprises the biodegradable fiber material in the form of fibers. The fibers can be present as individual fibers, as a fiber structure, or as a fiber group consisting of several interconnected fibers. The fibers represent the fiber material, regardless of whether they are in the pulp as individual fibers, as a fibrous structure, or as a group of fibers. The fibers are dissolved in the liquid solution such that they float in the liquid solution with as even a concentration as possible, regardless of location, for example as a mixture or suspension of liquid solution and fiber material. For this purpose, the pulp can be, for example, appropriately tempered and/or circulated in some embodiments. The pulp preferably has a low consistency, that is, a proportion of fiber material of less than 8%. In one embodiment, a pulp having a proportion of biodegradable fiber material of less than 5%, preferably less than 2%, particularly preferably between 0.5% and 1.0%, is used in the method according to the invention. This small proportion of fiber material can, inter alia, prevent the fiber material in the liquid solution from clumping so that the fiber material can still be molded onto the suction tool with a good level of quality. Although clumped fiber material can be sucked in by the suction tool, this would probably result in a molded part with a fluctuating layer thickness, which should be avoided in the production of the molded parts as far as possible. In this respect, the proportion of fiber material in the pulp should be small enough so that clumping or chaining does not occur or occurs only to a negligible extent. The liquid solution can be any solution suitable for the fiber molding process. For example, the pulp can be an aqueous solution comprising the biodegradable fiber material. An aqueous solution is, inter alia, an easy-to-handle solution.
The fiber molding process refers to the process steps that are involved in molding the molded part, starting with providing the pulp, molding the molded part in the suction tool from the fiber material of the pulp, pre-pressing the molded part, hot-pressing the molded part and, if necessary, coating the molded part with functional layers, wherein the coating can be arranged at any point in the fiber molding process that is suitable for the respective layer to be deposited.
The molded parts can have any shape, also referred to as a contour, provided that this shape (or contour) can be manufactured in the method according to the invention or the method is suitable for manufacturing this shape (or contour). For this purpose, the components used for the fiber molding process can be adapted to the respective shape (or contour) of the molded part. In the case of different molded parts having different shapes (or contours), different correspondingly 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, casings, or receptacles for a wide variety of purposes.
The suction tool in this case refers to the tool in which the suction head or heads for molding the molded part are arranged. In the case of a single suction head, this is also the suction tool. If there are several suction heads that are operated simultaneously, they are all arranged in the common suction tool, so that when the suction tool is moved, the individual suction heads in the suction tool are moved in equal measure. The supply of media to the suction tool comprising a plurality of suction heads is routed in a suitable manner to the individual suction heads in the suction tool.
Placing the suction tool on the pulp means that the pulp is in contact with all the suction heads in the suction tool, which are provided for molding molded parts, in such a way that, due to the negative pressure applied to the pulp by means of the suction tool, the fiber material is sucked out of the pulp or the pulp containing fiber material dissolved therein is sucked in. When partially dipping into the pulp, the suction tool is not merely placed on the pulp but dipped into it. The dip depth of the suction tool into the pulp depends on the respective application and the respective fiber molding process and can differ depending on the application and, possibly, the molded part to be formed. Partially dipping the suction head or the suction tool is advantageous since the pulp level in the reservoir could fluctuate due to the movements of the suction head/suction tool and, if the pulp has an uneven surface due to wave movements, merely placing said head or tool could result in locally insufficient suction.
The suction head can have what is referred to as a negative shape. A negative shape is a shape where the suction side of the suction head, that is, the side where the fiber material is deposited due to the suction effect of the suction head and thus forms the molded part, is located on the interior side of the suction head so that, after the suction head has been placed on the pulp or the suction head has been dipped into the pulp, said interior side forms a cavity into which the pulp containing the fiber material is sucked (as shown in
The suction head can alternatively also have what is referred to as a positive shape. A positive shape is a shape where the suction side of the suction head, that is, the side where the fiber material is deposited due to the suction effect of the suction head and thus forms the molded part, is located on the exterior side of the suction head so that, after the suction head has been placed on the pulp or the suction head has been dipped into the pulp, said exterior side does not form a cavity (as shown in
Molding the molded part involves initially pre-molding the molded part, wherein said part is formed from fiber material that was previously randomly distributed in the pulp by the fiber material accumulating on the contour of the suction head comprising the corresponding contour. The formed molded part still has a large proportion, for example 70%-80%, of liquid solution, for example water, and is therefore not yet stable in shape. The pre-pressing of the formed molded part significantly reduces the proportion of liquid solution in the molded part, for example to 55%-65%, so that the contour of the molded part is now much more stable. By means of the hot-pressing of the pre-pressed molded part with a hot-pressing pressure, the molded part is finished with a further reduction in the proportion of the liquid solution in the molded part, for example to below 10%, preferably to approximately 7%, after which it is then stable and resistant to deformation.
Outputting the finished molded part refers to issuing the molded part for onward transport or for further processing, for example to cutting, labeling, printing, and/or packing stations.
Combining the molding, pre-pressing, and hot-pressing steps, makes it easy to manufacture a molded part from a fiber material that, depending on the design of the contour of the suction head, can very flexibly yield molded parts 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 manufacture of the respective molded part. By combining the molding, pre-pressing, and hot-pressing steps, the molded parts can be manufactured in a very reproducible manner and with great accuracy and quality with regard to the shape and layer thickness of the individual molded part sections. The manufacturing method is able to process fibers of all kinds, provided that they can be dissolved such that major clumping of the fibers in the liquid solution before processing can be avoided. In this way, stable molded parts can, in particular, be manufactured easily, effectively, and flexibly from biodegradable fiber material with a good level of quality and reproducibility.
The method according to the invention thus represents a manufacturing method for environmentally friendly molded parts made of natural fibers and a corresponding machine by means of which said products (molded parts) can be reproducibly manufactured effectively, flexibly, and with a good level of quality.
In one embodiment, the pulp does not comprise any organic binder and, preferably, no non-organic binder either. Without a binder, the molded parts manufactured from originally biodegradable fiber material can continue to be degraded in an environmentally friendly manner since no environmentally critical binder, preferably no binder at all, is used. Outputting with binders is made possible by combining the molding, pre-pressing, and hot-pressing steps, which, as a whole, ensure good mechanical interlinking of the individual fibers with one another in the fiber material of the molded part. In the method according to the invention, the mechanical interlinking is so strong that, for the dimensional stability of the molded part, binders can be dispensed with.
In a further embodiment, the biodegradable fiber material substantially consists of fibers with a fiber length of less than 5 mm. In the case of fibers of this length, a good, homogeneous solution of the fiber material in the liquid solution, inter alia, is obtained so that the degree of clumping of the fibers in the pulp is low enough for a good, reproducible fiber molding process for the molded part.
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., particularly preferably room temperature. These low temperatures allow for, inter alia, straightforward process management, in particular at room temperature.
In a further embodiment, the pulp comprises dopants or components which 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 care additives, etc., which, due to their subsequent use and the then prevailing conditions, diffuse out of the fiber material, are dissolved, or remain when the molded part is biodegraded.
In a further embodiment, the suction head is completely dipped into the pulp for contacting. Dipping in completely is particularly suitable for a suction head as a positive shape since, in contrast to a negative shape, there is no internal cavity in the suction head in which a negative pressure can be generated between the pulp and the suction surface in order to suck in the fiber material. In order to ensure that the fiber material is sucked up as uniformly as possible, it is advantageous in the case of a positive shape to dip the suction head completely into the pulp.
In a further embodiment, the suction head suction side of the suction head is formed from a porous screen, to whose pulp side that faces the pulp the biodegradable fiber adheres due to the suction for molding the molded part. The screen must have a porosity so that the pulp together with the fiber material can be sucked through the screen and the liquid solution of the pulp can pass through the screen. However, the porosity of the screen must not be too great so that the fibrous material can adhere to the pulp side.
In a further embodiment, the liquid solution of the pulp passing through the screen is discharged from the suction tool during the molding. During the molding or sucking, the content of the liquid solution in the formed fiber material is already reduced by, for example, about 20%-30% in relation to the pulp. This liquid solution passes through the screen into the suction head. So that the suction head does not have to store the liquid solution temporarily, it is discharged from the suction head and thus also from the suction tool. The discharged liquid solution can be returned to a pulp conditioner and reused in the fiber molding process.
In a further embodiment, the suction head comprises, on its end face that faces the pulp, a collecting ring for receiving the liquid solution to be discharged, to which a discharge channel for the liquid solution is connected. In this way, the liquid solution that has passed through the screen can, inter alia, be safely 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.
In a further embodiment, the suction tool comprises a plurality of suction channels distributed around the side of the screen that is opposite the pulp side. Due to the large number of suction channels, it is possible, inter alia, to suck in pulp containing fiber material over the entire surface of the screen so that the molded part can be formed in a sheet-like manner on the screen.
In a further embodiment, the suction channels are distributed and arranged around the screen and a structure of the screen is designed such that a substantially equal suction power is applied to all regions of the pulp side of the screen. In this case, the term “substantially” refers to a homogeneity of the suction power that is sufficient to achieve a uniformly formed molded part without significant layer thickness variations at the corners and edges of the molded part and over the surfaces of the molded part. The resulting finished molded part has a layer thickness variation of less than 7% from the desired layer thickness. In a further embodiment, the suction channels have an uneven distribution below the screen, wherein approximately 50% fewer suction channels per surface unit are arranged in the region of (negative shapes or inner edge) edges in the molded part. In the case of positive or outer edges, the number of suction channels is increased by approximately 20% per surface unit. This lower density of suction channels in the area of edges (in this case referring to all corners and edges, indentations, and other major contour changes in the molded part) means that material excesses or material shortages in the region of the edges relative to other material thicknesses on surfaces without edges are avoided.
In a further embodiment, the suction tool is a multi-tool with a large number of suction heads. Using a multi-tool, a large number of molded parts can be formed simultaneously from a common pulp bath, depending on the number of suction heads, which increases the throughput of the fiber molding system and thus allows the fiber molding system to produce more economically.
In a further embodiment, the suction head suction surface is designed either as a negative shape, the interior side of the suction head, or as a positive shape, the exterior side of the suction head. Regarding the terms “negative shape” and “positive shape,” reference is made to the explanations above. Depending on the desired shape or contour of the molded part, negative shapes or positive shapes of the suction head can be advantageous.
In a further embodiment, the molded part remains on the suction tool for pre-pressing. Since the molded part is still relatively moist when it is formed in the suction head and is therefore not very dimensionally stable, it is advantageous for a fault-free and high-quality process to leave the molded part in the suction head at least until the end of the pre-pressing in order to avoid shape changes for the molded part that could damage the mold.
In a further embodiment, the pre-pressing station comprises a pre-pressing lower tool, to which the suction tool with the formed molded part is attached, and therefore it is arranged between the pre-pressing lower tool and the suction tool and the suction tool is pressed onto the pre-pressing lower tool by means of the pre-pressing pressure. The suction tool is designed to be suitable for exerting the pre-pressing pressure on the pre-pressing lower tool. In this case, the suction tool can be pressed onto a stationary pre-pressing lower tool or the pre-pressing lower tool is pressed onto a stationary suction tool. The term “attach” only refers to the movement of the suction tool relative to the pre-pressing lower tool. During the pre-pressing, the suction tool represents the pre-pressing upper tool of the pre-pressing station. In one embodiment, the suction tool is placed on the pre-pressing lower tool and, by means of a separate pressing unit, preferably a plunger rod, pressed onto the pre-pressing lower tool. Alternatively, the suction tool can also be attached to a robot arm, which itself exerts the pre-pressing pressure on the pre-pressing lower tool via the suction tool. Analogous to a suction tool as a multi-tool, the pre-pressing lower tool can also be designed as a multi-tool in order to apply the pre-pressing pressure to all formed molded parts of the suction tool simultaneously and thus carry out the pre-pressing for all molded parts simultaneously.
In a further embodiment, the suction tool with the negative shape is placed on the pre-pressing lower tool (with the corresponding positive shape) as the suction head suction surface or is inserted into the pre-pressing lower tool (as the corresponding negative shape) with the positive shape as the suction head suction surface.
In a further embodiment, the pre-pressing lower tool has a pressing surface that faces the molded part and has a lower surface roughness than the screen. As a result, a homogeneous pressure is exerted on the molded part. In addition, the adhesion between the pre-pressing lower tool and the molded part is lower than with structured surfaces of the pre-pressing lower tool, as a result of which it is ensured that, without additional technical measures, the pre-pressed molded parts remain in the suction tool for transfer to the hot-pressing station and not on the pre-pressing lower tool, which would cause a disruption in the production process. If necessary, the suction tool can generate a suitable negative pressure in the suction tool for transferring the pre-pressed molded parts to the hot-pressing station in order to improve the adhesion of the molded parts to the suction tool.
In a further embodiment, the pre-pressing lower tool is made of metal or at least partially made of an elastomer, preferably made of silicone. Pre-pressing lower tools made of metal are particularly suitable for cases where a temperature above room temperature or a particularly high pre-pressing pressure is to be applied during pre-pressing. Pre-pressing lower tools made of an elastomer or at least partially made of the elastomer are advantageous in the case of multi-tools as a suction tool and a pre-pressing lower tool since the elastomer can still be easily deformed under pressure, thus adapting in a flexible manner to a multi-suction tool that may bend under the pre-pressing pressure and subsequently improving the homogeneity of the shaping of the various molded parts in the multi-suction tool. For increased pre-pressing temperatures below 100° C., for example, silicone as an elastomer is also highly suitable as a temperature-resistant material in this range.
In a further embodiment, the pre-pressing is carried out as membrane pressing. Membrane pressing is particularly suitable for geometries of the molded part where pressure is to be exerted on a large surface. Using a membrane press, surfaces that are perpendicular to one another in any spatial orientation can also be put under the same pressure simultaneously since, during membrane pressing, the pre-pressing pressure is generated by means of gas pressure, for example compressed air, which acts on the membrane in any direction. This would not be possible with a pressure plunger rod, for example.
In a further embodiment, the pre-pressing lower tool for membrane pressing is therefore designed as a flexible membrane and the pre-pressing pressure is applied to the membrane as gas pressure, which membrane is then pressed onto the outer contour of the molded part. For this purpose, the membrane is gas-impermeable and flexible in order to be able to conform to the shape of the molded part under gas pressure. Rubber membranes, for example, can be used as membranes. The membrane should have a contour fidelity of less than 20% and can be designed differently locally, for example with thinner and thicker walls and/or arranged closer to the contour or further away from it.
In a further embodiment, the pre-pressing is carried out at a temperature of the pre-pressing station of less than 80° C., preferably less than 50° C., particularly preferably at room temperature. The pre-pressing reduces the liquid content in the molded part to approximately 55%-65% and the molded part is pre-solidified such that it is sufficiently dimensionally stable for tool transfer. Too high a temperature would lower the liquid content in the molded part too much, as a result of which the material would be too stiff for the subsequent hot-pressing. The combination of pre-pressing and hot-pressing in particular enables the reproducible manufacture of high-quality molded parts with a low number of rejects.
In another embodiment, the pre-pressing is carried out at the 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, enable gentle solidification of the molded part with a moderate reduction in liquid, which is advantageous for a low-waste hot-pressing process.
In a further embodiment, after pre-pressing has taken place, the method comprises the step of transferring the pre-pressed molded part to the hot-pressing station by means of the suction tool, wherein the molded part is removed from the suction tool for subsequent hot-pressing. The transfer is advantageous in that the hot-pressing is carried out at a high temperature with a significantly higher pressure. If the molded part were to remain in the suction tool without being transferred for hot-pressing, the fiber material could get caught in the screen of the suction tool and only be removed from the suction tool with difficulty, possibly only by causing damage after hot-pressing. In addition, the screen could be damaged by the high pressure, and therefore the suction tool would then no longer be functional. The transfer can take place in such a way that the molded part or parts are transferred from the suction tool to the hot-pressing station passively by being laid down or actively by means of an ejection pressure in the suction tool against the molded parts.
In a further embodiment, the hot-pressing station comprises a hot-pressing lower tool with a hot-pressing side adapted to a contour of the molded part and a correspondingly shaped hot-pressing upper tool, wherein the molded part is placed on or inserted into the hot-pressing lower tool from the suction tool during the transfer and, during the hot-pressing, the hot-pressing upper tool is pressed onto the hot-pressing lower tool with the molded part arranged in between. Depending on whether the suction heads of the suction tool have a negative or positive shape, the molded part is placed on (negative shape) or inserted into (positive shape) the hot-pressing lower tool. In this respect, the hot-pressing side is the exterior side in the case of a negative shape and the interior side of the lower tool in the case of a positive shape. The hot-pressing upper tool is formed in a correspondingly complementary manner, in each case. The two hot-pressing upper and lower tools can work together to apply high pressures at high temperatures to the molded part in between. In a further embodiment, at least the hot-pressing lower tool is made of metal for this purpose.
In a further embodiment, the hot-pressing lower tool comprises channels on its exterior side, by means of which the liquid solution can be at least partially discharged during the hot-pressing. By reducing the liquid (or moisture) in the molded part from approximately 55%-60% to below 10% from this point on, a quantity of liquid is released, which at least partially evaporates due to the high temperatures during the hot-pressing. This steam is therefore discharged via the channels so that the molded part is not damaged by the steam, inter alia.
In a further embodiment, the hot-pressing upper tool is adapted to the contour of the molded part, at least with the side that faces the molded part; the hot-pressing upper tool is preferably made of metal.
In a further embodiment, the hot-pressing lower tool and the hot-pressing upper tool have different temperatures during the hot-pressing; the hot-pressing upper tool preferably has a higher temperature than the hot-pressing lower tool. This gives the molded part, inter alia, a better surface, in particular on the warmer side. In a further embodiment, the temperatures differ by at least 25° C., preferably not more than 60° C., particularly preferably by 50° C.
In a further embodiment, the hot-pressing is carried out at a temperature greater than 150° C., preferably between 180° C. and 250° C. This allows the liquid (or moisture) in the molded part to be reduced to less than 10%.
In a further embodiment, the hot-pressing is performed at the hot-pressing pressure, which is higher than the pre-pressing pressure. In this way, the liquid (or moisture) in the molded part can be reduced to less than 10%, in particular in combination with the above-mentioned temperatures. In a further embodiment, the hot-pressing pressure is between 0.5 N/mm2 and 1.5 N/mm2, preferably between 0.8 N/mm2 and 1.2 N/mm2.
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, even more preferably 12 s. In this way, the liquid (or moisture) in the molded part can be reduced to less than 10%, in particular in combination with the above-mentioned temperatures and hot-pressing pressures.
In a further embodiment, the contour of the molded part is designed such that all surfaces of the molded part have an angle a of at least 3 degrees to the pressing direction during the hot-pressing. This ensures that the hot-pressing pressure can be applied to all surfaces of the molded part. No pressure can be exerted to surfaces parallel to the direction of pressure during the hot-pressing. The hot-pressing pressure is applied hydraulically to the hot-pressing station, for example via a plunger rod, wherein this piston rod presses, for example, on the hot-pressing upper tool, which in turn presses on the stationary hot-pressing lower tool, with the molded part in between. The arrangement could also be inverted.
In a further embodiment, the finished shaped molded part is then dispensed to further processing stations of the fiber molding system, for example for onward transport or for further processing, for example at a cutting, labeling, printing, and/or packing station.
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 additional functionalities such as moisture, aroma, odor, or taste barriers.
The invention also relates to a fiber molding system for manufacturing molded parts from biodegradable fiber material by means of the method according to the invention, comprising:
In this case, the outputting unit dispenses the molded part for onward transport or for further processing, for example to subsequent cutting, labeling, printing, and/or packing stations.
The combination of molding by means of pulp and a suction tool, pre-pressing by means of a pre-pressing station, hot-pressing by means of a hot-pressing station, and subsequent outputting of the molded part by means of the above-mentioned fiber molding system makes it easy to manufacture a molded part from a fiber material that, depending on the design of the contour of the suction head, can very flexibly yield molded parts with a wide range 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 manufacture of the respective molded part. By combining the suction tool for molding with the pre-pressing and hot-pressing stations, the molded parts can be manufactured in a very reproducible manner and with great accuracy and quality with regard to the shape and layer thickness of the individual molded part sections. The fiber molding system according to the invention is able to process fibers of all kinds, provided that they can be dissolved such that major clumping of the fibers in the liquid solution before processing can be avoided. In this way, stable molded parts can, in particular, be manufactured easily, effectively, and flexibly from biodegradable fiber material with a good level of quality and reproducibility.
The fiber molding system according to the invention thus makes it possible to reproducibly manufacture environmentally friendly molded parts from natural fibers in an effective, flexible, and with a good level of quality.
In one embodiment, the fiber molding system comprises a control unit for controlling the method that is carried out. The control unit can be designed as a processor, separate computer system, or web-based and is suitably connected to the components of the fiber molding system which are to be controlled, for example, via data cable or wirelessly by means of WLAN, radio, or other wireless transmission means.
In a further embodiment, the fiber molding system also comprises a coating unit for depositing one or more functional layers onto the molded part. With such functional layers, additional functionalities such as moisture, aroma, odor, or taste barriers can be applied to the molded part. For this purpose, the coating unit can be arranged at any position in the process sequence for manufacturing the molded part that is suitable for the layer to be deposited. Depending on the application in the suction process, the functional layer can be arranged after the pre-pressing or after the hot-pressing. In this case, the term “functional layer” refers to any additional layer applied to the original fiber material, which is applied both to an interior side and/or to an exterior side of the molded part over the whole surface or in partial regions.
The invention also relates to a molded part made from biodegradable fiber material manufactured by means of the method according to the invention or the fiber molding system according to the invention.
In one embodiment, the molded part has a contour in which all surfaces of the molded part have an angle of at least 3 degrees to a pressing direction during the hot-pressing. With such a molded part, a minimally required hot-pressing pressure can be applied to all surfaces in order, inter alia, to reduce the content of liquid solvent in the fiber material to such an extent that the molded part is dimensionally stable.
In a further embodiment, the biodegradable fiber material does not comprise any organic binder and, preferably, no non-organic binder either. This achieves particularly good biodegradability of the molded part.
In a further embodiment, the globally degradable fiber material substantially consists of fibers with a fiber length of less than 5 mm. As a result, the molded part can be manufactured with better quality. In addition, shorter fibers reduce the surface roughness and porosity of the molded part, making it easier to apply any coatings to the molded part.
In a further embodiment, one or more functional layers are deposited on the biodegradable fiber material of the molded part. Such functional layers can include additional functionalities such as moisture, water, aroma, odor, or taste barriers or barriers for fats, oils, gases such as O2 and N2, light acids, and all substances that contribute to food perishability, and/or have non-food grade substances.
In a further embodiment, the fiber material of the molded part comprises dopants or components that, due to their concentration, an application of the molded part, and environmental conditions, are released from the fiber material of the molded part in the desired manner in order to have a supporting effect on the application of the molded part. Said dopants or components can already be present in the pulp and get into the molded part during the fiber molding process. Such dopants can be, for example, fragrances, flavorings, active ingredients, minerals, nutritional and care additives, etc.
It should be expressly pointed out that, for the purpose of better readability, “at least” expressions have been avoided as far as possible. Rather, an indefinite article (“one”, “two”, etc.) is generally to be understood as “at least one”, “at least two”, etc., unless it follows from the context that “exactly” the specified number is meant in that case.
At this point, it should also be mentioned that, within the scope of the present patent application, the expression “in particular” is always to be understood as introducing an optional, preferred feature. The expression is therefore not to be understood as “specifically” and not as “namely.”
It goes without saying that features of the solutions described above or in the claims can also be combined if necessary in order to be able to cumulatively implement the advantages and effects that can be achieved here.
In addition, further features, effects, and advantages of the present invention are explained with reference to the attached drawing and the following description. Components that at least substantially correspond in terms of their function in the individual Figures are identified by the same reference symbols, with the components not having to be numbered and explained in all Figures.
In the drawings:
At this point, it should be explicitly pointed out that features of the solutions described above or in the claims and/or drawings can also be combined, if necessary, in order to be able to cumulatively implement or achieve explained features, effects, and advantages.
It goes without saying that the embodiment explained above is merely a first embodiment of the present invention. In this respect, the configuration of the invention is not limited to this embodiment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 127 557.1 | Oct 2019 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2020/000227 | 10/1/2020 | WO |
