US20250382751A1
Three-dimensional molded part made of fiber-containing material and molding tool for the production of molded parts made of fiber-containing material
Publication
Application
Classifications
IPC Classifications
CPC Classifications
Applicants
Kiefel GmbH
Inventors
Till Rupp, Richard Hagenauer
Abstract
A three-dimensional molded part made of fiber-containing material and a molding tool for producing molded parts made of fiber-containing material are described. The molded part is produced from fiber-containing material in a production process under pressure and thermal action. A surface of the molded part has elevations formed by fiber-containing material that has been sucked into corresponding openings in a molding surface of a molding tool during the production of the molded part when steam emerging from the fiber-containing material during pressing is removed. The elevations form at least one pattern along a surface of the molded part.
Figures
Description
PRIORITY CLAIM
[0001]The present application claims priority under 35 U.S.C. § 119 to German Patent Application No. DE 10 2024 117 152.9, filed Jun. 18, 2024, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002]A three-dimensional molded part made of fiber-containing material and a molding tool for producing molded parts made of fiber-containing material are described.
BACKGROUND
[0003]Fiber-containing materials are increasingly used, for example, to produce packaging for food (e.g., trays, capsules, boxes, etc.) and consumer goods (e.g., electronic devices, etc.) as well as beverage containers. The fiber-containing materials can have natural fibers, which are obtained, for example, from renewable raw materials or waste paper. The natural fibers can be mixed in a so-called pulp with water and, optionally, further additives, such as starch, and then formed. Additives can also have an effect on color, barrier properties and mechanical properties. A pulp can have a proportion of natural fibers of, for example, 0.1 to 10 wt. %. The proportion of natural fibers can vary according to the method used for the production of packaging, etc., and the product properties of the product to be produced. Fibers, such as natural fibers, can also be introduced into molding tools in a dry state and processed or formed therein. Alternatively, such fibers can be processed into starting materials for subsequent shaping. Starting materials for further processing can, for example, be so-called webs or sheets, such as airlaid, fluff pulp, paper, etc., as well as multi-layer arrangements made of the above materials, made of a fiber-containing material, which are then formed in a molding tool.
[0004]During the production of products or molded parts from a fiber-containing material, the evaporating water is extracted as standard during a pressing process at high temperatures and high pressure in a so-called wet process. Even in dry molding processes, the so-called dry process, steam can be extracted during a pressing process with high temperatures and high pressure if the fiber-containing material has a water content of about 20 wt. % or more or has at least been locally moistened. To extract the steam, the molding surfaces of molding tools have small openings that are connected to corresponding channels and devices. During the pressing process, small elevations form on the surfaces of the molded parts, with the fiber-containing material being pressed into the openings. Extraction can support the formation of elevations.
[0005]Such elevations arise as a result of extraction, where with increasing moisture content of the material to be pressed in cavities of molding tools, more and more steam is generated, which must be discharged via openings on at least one molding surface of a molding tool. The elevations are perceptible both visually and haptically on a finished molded part.
[0006]However, the elevations are perceived as disruptive with regard to design specifications and aesthetic aspects, so that the demand for alternative molded bodies made of renewable and easily recyclable fiber-containing materials, which can also be compostable, is very low. This is a crucial disadvantage, especially with regard to the goal of using more sustainable products. In addition, such elevations have the disadvantage that when used, for example as a capsule for a coffee machine or as a lid for a drinking cup, they do not sit flush with contact surfaces (e.g., brewing chamber for a coffee capsule) or do not fit optimally against the edge of a cup, so that a sufficient sealing effect cannot be achieved. Furthermore, such elevations on a lid can make drinking difficult.
SUMMARY
Object
[0007]By contrast, it is an object to provide a solution that eliminates the disadvantages of the prior art and enables the formation of molded parts from fiber-containing material and provides molded parts from fiber-containing material that are simply designed, are not subject to any functional restrictions in the use of molded parts due to elevations resulting from the manufacturing process and take aesthetic requirements into account.
Solution
[0008]The above-mentioned object is achieved by a three-dimensional molded part made of fiber-containing material, which is produced in a production process under pressure and thermal influence, where a surface of the molded part has at least one elevation that is formed by fiber-containing material that, during the production of the molded part, has been suctioned and/or pressed into a corresponding opening in a molding surface of a molding tool when steam that escapes from the fiber-containing material during pressing is removed, and where the elevations along a surface of the molded part form at least one pattern.
[0009]The arrangement of elevations as a pattern offers, on the one hand, a visually appealing appearance that can also be used to display product information, usage and disposal instructions, and, on the other hand, can take into account a technical aspect, where patterns can, for example, be designed in the form of a line that facilitates insertion into a receiving space (e.g. brewing space for a coffee capsule) or prevents incorrect insertion (formation of elevations to provide elements according to the “Poka Joke” principle).
[0010]In further embodiments, the at least one pattern can be integrated at least partially into a transition between at least a first surface portion and a second surface portion of the surface and/or into a design element on the surface.
[0011]When integrating the at least one pattern into a first surface portion with a configuration that differs from a second surface portion, the at least one pattern can be integrated into a portion or region (first surface portion) of a surface of the molded part that already differs in its configuration (shape, depth, thickness, etc.) and thus also visually and haptically from the remaining surface region or neighboring regions (second surface portion). This ensures that the elevation of at least one pattern does not have a disturbing visual appearance because it is integrated into a region that is already formed differently for design and/or technical reasons, and is not disturbing when using the molded part because the at least one elevation does not protrude from a contact surface or plane due to its integration into a differently formed region, for example, so that no “locking points,” “spacer knobs” or the like are formed.
[0012]For example, elevations of the at least one pattern can be provided in regions of a molded part with reduced material thickness so that no elevations protrude from the surface to the extent that the elevations in the regions with reduced material thickness protrude at most to such an extent that their protruding ends are substantially flush with the surface profile of the surrounding regions of the second surface portion. In other words, elevations cannot protrude above a surface plane that extends over the first surface portion and the second surface portion. Furthermore, elevations can also protrude deliberately from a surface plane, where the elevations are part of a configuration.
[0013]The different configuration of a first surface portion can be formed in different ways. For example, the configuration can include transitions, general elevations, i.e., thickened regions, design elements, depressions, formation elements, etc. Elevations can be provided in a first surface portion on an outer surface and/or inner surface. The elevations themselves usually extend perpendicularly from the surface and have small dimensions. For example, elevations can have diameters of 0.5 to 2 mm or corresponding cross sections. The height of elevations can, for example, be in the range of 0.2 to 1.5 mm. The dimensions may also be designed according to the layer thickness of the molded part in the region of the material layer assigned to the surface and the dimensions of the molded part as well as the material used and the intended use and may deviate from the above exemplary dimensions. Molded parts can be designed in different ways and, for example, have a round or polygonal cross section.
[0014]In further embodiments, the at least one pattern can have at least one first elevation and at least one second elevation, where the at least one first elevation and the at least one second elevation differ from one another in their configuration.
[0015]The molded part can also have a plurality of first surface portions, each of which has at least one pattern, where the patterns and/or the first surface portions can each be formed differently.
[0016]In further embodiments, the first surface portion may differ from the at least one second surface portion with regard to at least one of surface type, orientation, arrangement, structure, material type and/or profile. This also includes regions with reduced material thickness. In particular, this may include depressions, transitions between edge, side and/or base regions, embossing, etc.
[0017]In further embodiments, the at least one pattern may represent a product feature, a product representation, an instruction on the use of a product and/or on the disposal of the molded part. For example, symbols, letters, numbers, etc. can be formed by depressions, protruding regions and other surface characteristics (e.g., structure, roughness, etc.), where the at least one pattern is integrated in such a surface portion.
[0018]In further embodiments, the at least one pattern may extend over a wall region, an edge region and/or a bottom region of a molded part.
[0019]In further embodiments, the elevations of the at least one pattern can be arranged on an outer surface of the molded part and extend away from the outer surface of the molded part.
[0020]In further embodiments, the at least one elevation can have an at least partially oval, elongate, polygonal or round cross section. The at least one elevation can be part of a design element or can constitute a substantial component thereof. In further embodiments, patterns can contain information and/or represent a functional element that serves, for example, as a spacing element, guide element and/or marking. Thereby, in further embodiments, the at least one pattern can be designed as holding or spacer ribs (e.g., for containers for hot or cold food/drinks) or as rough gripping surface with a plurality of elevations.
[0021]In further embodiments, at least one elevation can be formed as a design element.
[0022]In further embodiments, the fiber-containing material may include at least 50 wt. % of plant fibers and/or cellulose fibers.
[0023]The above-mentioned object is also achieved by a molding tool for producing molded parts from fiber-containing material according to one of the above embodiments, where the molding tool has at least one molding surface for pressing fiber-containing material into a three-dimensional molded body, where the at least one molding surface has openings for discharging steam from fiber-containing material during a pressing process, where the openings are arranged in the form of a pattern.
[0024]The molded parts specified above with regard to the molded part also apply accordingly to a molding tool for producing such molded parts, where molded parts can be produced using simple means without a complex and vulnerable tool design, which fulfills the above requirements and solves the problem mentioned at the outset.
[0025]Further features, embodiments and advantages result from the following illustration of exemplary embodiments with reference to the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0026]In the figures:
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
DETAILED DESCRIPTION
[0033]Various embodiments of the technical teaching described herein are shown below with reference to the figures. Identical reference signs are used in the figure description for identical components, parts and processes. Components, parts and processes that are not substantial to the technical teachings disclosed herein or that are obvious to a person skilled in the art are not explicitly reproduced. Features specified in the singular also include the plural unless explicitly stated otherwise. This applies in particular to statements such as “a” or “one.”
[0034]
[0035]The molded part 100 has a base 102 that has a base ring 104. The base ring 104 protrudes from the surface of the base 102. The molded part 100 has an adjoining circumferential side wall 110. The side wall 110 is slightly inclined relative to the base 102, where the diameter of a receiving space of the molded part 100 increases from the base 102 to an edge 150. In the exemplary embodiment shown, the molded part 100 is substantially rotationally symmetrical. The side wall 110 has a thickened or stepped ring 112. In the region of the ring 112, the material thickness or the thickness of the side wall 110 can be stronger or greater than in the remaining region. Alternatively, the cross section or diameter of the side wall 110 may increase in the region of the ring 112 in order to provide a substantially constant wall thickness over the entire side wall 110. A second transition 116 having a radius is formed between the ring 112 and the side wall 110. A first transition 114 from the ring 112 to an edge 150 also has a radius. In the embodiment shown, elevations 160 are formed at various locations on the surface 106 of the molded part 100.
[0036]Three design elements 130 are integrated into the side wall 110 and are formed during the pressing of the fiber-containing material in a molding tool 200 (see, for example,
[0037]In the embodiment according to
[0038]By integrating the elevations 160 or pattern 162 into the embodiment of the design elements 130 (“coffee bean”), these elevations 160 are barely perceptible and blend in with the embodiment both visually and haptically. In the exemplary embodiment with the coffee bean, the design element 130 has a web 132 in the first surface portion 120. The web 132 protrudes from the neighboring regions 140, each of which has a smaller material thickness or wall thickness than the web 132 and the second surface portion 122. The elevations 160 on the webs 132 or the coffee bean pattern formed thereby are thus integrated into the different embodiment of the design element 130 compared to the second surface portion 122.
[0039]Furthermore, elevations 160 are integrated into the transitions 114, 116 and a transition region between the base ring 104 and the base 102 or into the base ring 104, so that these elevations do not have a significant influence on the use of the molded part 100, i.e., they do not form any protruding elements that are arranged on visible surfaces on the surface 106 or that are disruptive to abutment against corresponding surfaces of a utilization machine (e.g., coffee machine). The elevations 160 on the base 102 and on the edge 150 may also be omitted in further embodiments. In the exemplary embodiment, these are shown as an embodiment option on further first surface portions that differ from the remaining surface 106, in particular the surface 106 of the side wall 110 in the second surface portion 122, due to the orientation and arrangement as well as the surface characteristics. The base 102 has, for example, a surface offset from the base ring 104, so that the central elevations 160 do not interfere with the use of the molded part 100 and are also barely perceptible. The edge 150 has a rougher surface, so that the elevations 160 on the edge 150 are barely perceptible both visually and haptically and are also not located on relevant functional surfaces, in particular for later use (e.g., coffee machine).
[0040]
[0041]
[0042]
[0043]The design element 130 has a region 140 with reduced material thickness or wall thickness, as can be seen in particular in the sectional view. In a first sub-region 142, the side wall 110 has a decreasing material thickness in the region of the design element 130, which decreases further up to a second sub-region 144 and reaches its maximum. The material or wall thickness along the web 132 remains unchanged in the exemplary embodiment. In further embodiments, the material or wall thickness of the web 132 can also decrease, where the degree of decrease can be different from the regions 140 in order to achieve a visually and haptically perceptible difference between regions 140 and a web 132. This may be necessary in particular if, for example, a web 132 has a profile that, during demolding, collides with the molding surface of a molding tool 200 and could be damaged in the process.
[0044]In further embodiments, the formation of a step in the first region 142 relative to the outer surface 106 can be tolerated in order, for example, to achieve a delimitation between the first region 142 and the surface 106. Such a step can form an undercut in a molded part 100. Up to a certain depth (e.g., 1 mm) or undercut formation, demolding can thus take place after the molding process in a molding tool without moving parts, without damaging the molded part 100.
[0045]As depicted in
[0046]
[0047]In addition, the material or wall thickness of the web 132 can also decrease or an elevation 160 can be provided in a sub-region 142 or 144 so that the elevation 160 does not protrude or only protrudes slightly from the overall surface or the surface of a second surface portion 122, as depicted schematically in
[0048]
[0049]The molded part 100 is shown, like the molded parts 100 from
[0050]On the right side, the side wall 110 of the molded part 100 has two regions 140 with reduced wall thickness, where one region has a web 132 or an element designed analogously thereto, on which the elevations 160 are formed and protrude from the design element 130 (lower example), or the elevations 160 are arranged in, for example, a sub-region 144 with a small material thickness, so that the elevation 160 does not protrude above the surface of the surrounding second surface portion 122 (upper example).
[0051]
[0052]Elevations 160 can be components of a design element 130 and follow a profile of elements (e.g. a web 132), or can themselves be a design element, e.g. a letter (“L”).
[0053]In further embodiments, character strings or symbols can also be realized by several appropriately designed elevations 160 that form a pattern 162 and, for example, give a consumer an indication of use or disposal.
[0054]
[0055]In the exemplary embodiment shown, the molding tool 200 has a first tool part 210 and a second tool part 230. The first tool part 210 and the second tool part 230 include or consist essentially of a metal (e.g., aluminum) or a metal alloy, which are suitable for pressing fiber-containing material at temperatures in the range of 120 to 300° C. and a pressure of 0.2 to 300 N/mm2. The tool parts 210, 230 each have a molding surface 212, 232 for pressing fiber-containing material. The molding surfaces 212, 232 may also have a special surface coating or design to prevent damage to the molding surfaces 212, 232 due to the moisture contained in the fiber-containing material and the steam escaping during pressing.
[0056]In the exemplary embodiment depicted, the lower molded part 210 has a heating device 220. In further embodiments, the heating device 220 may extend into an upper molding region and/or have further heating elements. In still further embodiments, the upper tool part 230 may additionally or alternatively have a heating device with at least one heating element. Heating devices can, for example, have heating elements in the form of electrically controllable heating cartridges, etc.
[0057]
[0058]In the exemplary embodiment depicted, the lower tool part 210 has a substantially smooth molding surface 212. The molding surface 232 has openings 234 through which the moisture that arises during the pressing of fiber-containing material under high pressure and due to the temperature introduced via at least the tool part 210 and that escapes from the fiber-containing material in the form of steam is removed. For this purpose, channels 236 run from the openings 234 through the tool part 230. In the exemplary embodiment depicted, the channels 236 open into a common channel that is connected via a connection to further devices for discharging the steam. For example, devices for generating negative pressure can be connected to it so that the resulting steam is actively extracted.
[0059]In further embodiments, several connections can be provided, through which the steam can be discharged from a tool part 230 or 210. In further embodiments, a lower tool part 210 can also have openings 234 and channels 236.
[0060]Due to the openings 234, elevations 160 are formed on the inner and/or outer surface 108, 106 of a molded part 100, indicated schematically by the dashed lines, as described above. Although the extension of the elevations 160 and their dimensions are relatively small and can be influenced by appropriate dimensioning of the openings 234, elevations 160 are visually and haptically perceptible in previously known embodiments and molded parts. The solution of integrating elevations 160 into surface portions 120 and design elements 130, which has already been presented with reference to the embodiments of
[0061]The molding tool 200 shown is simply designed to form such molded parts 200 and has no moving components on the molding surfaces 212, 231, which are required for integrating the elevations. Thus, with the presented tool design, the integration of the elevation 160 can be easily implemented.
[0062]To form design elements 130 with regions 140, the molding surface 232 has bulges 238, for example to produce an element 130 on the side wall 110 of a molded part 100, as depicted in
[0063]The formation of the bulges 238 on the molding surfaces 232 enables molding in the molding direction FD without additional moving elements since the molding surfaces 212, 232 in the region of the bulges 238 form no undercut.
[0064]The openings 234 shown as examples are located in the exemplary embodiment at the position of the molding surface 232, which serve for the formation of design elements 130 and/or at first surface portions 120.
[0065]The production of molded parts 100 from a fiber-containing material includes a step of providing fiber-containing material that has, for example, a moisture content of between 50 and 70 wt. %, so that steam is generated during pressing, which steam must be removed from the cavity of a molding tool 200 between the molding surfaces 212, 232. Since the generation of steam is crucial during pressing, it is the moisture content and not the type of material that matters. For example, steam may only need to be removed locally. Thus, steam removal can be part of a wet (forming) process or a dry (forming) process.
[0066]In a so-called wet process, preforms made of a fiber-containing material can first be provided, which are then pressed under the action of heat. The preforms can be prepared in such a way that fibers are suctioned out of an aqueous solution (pulp) and three-dimensional preforms are formed that substantially already have the shape of the products to be manufactured. In addition, additives such as starch, chemical supplements, wax, etc. can be added to a pulp to influence the properties of the products to be manufactured (e.g., barrier properties) and the processability. The fibers can be, for example, natural fibers, such as cellulose fibers, or fibers from a fiber-containing original material (for example waste paper). Since a fiber-containing pulp with natural fibers can be used as the starting material for the molded parts 100, after being used, the molded parts 100 produced can themselves once again be used as a starting material for producing molded bodies 100 or other products, or they can be composted, because they can usually be completely decomposed and do not contain any dangerous substances that are harmful to the environment.
[0067]In other embodiments, the preforms can be subjected to a pre-pressing step. The preforms are then pressed into three-dimensional molded parts 100 in a molding tool 200 under pressure and the action of heat.
[0068]Furthermore, the molded parts 100 can be formed from a loose cellulose web (airlaid) or a paper that has at least locally a sufficient moisture content.
[0069]After molding in the molding tool 200, produced molded parts 100 can be ejected, which can then be subjected to post-treatment in another device or in the same device. Post-treatment may include, for example, lamination, printing, etc. In further embodiments, molded parts 100 can be treated in other ways after their production, in order to achieve certain properties.
[0070]The formation of molded parts 100 can vary depending upon the desired form.
LIST OF REFERENCE SIGNS
- [0071]100 Molded part
- [0072]102 Base
- [0073]104 Base ring
- [0074]106 Outer surface
- [0075]108 Inner surface
- [0076]110 Side wall
- [0077]112 Ring
- [0078]114 First transition
- [0079]116 Second transition
- [0080]120 First surface portion
- [0081]122 Second surface portion
- [0082]130 Design element
- [0083]132 Web
- [0084]140 Region
- [0085]142 First sub-region
- [0086]144 Second sub-region
- [0087]150 Edge
- [0088]160 Elevation
- [0089]162 Pattern
- [0090]200 Molding tool
- [0091]210 First tool part
- [0092]212 Molding surface
- [0093]220 Heating device
- [0094]230 Second tool part
- [0095]232 Molding surface
- [0096]234 Opening
- [0097]236 Channel
- [0098]238 Bulge
Claims
1. A three-dimensional molded part made of fiber-containing material that is produced in a production process under pressure and thermal action, wherein a surface of the molded part has elevations formed by the fiber-containing material that has been sucked into corresponding openings in a molding surface of a molding tool during the production of the molded part when steam escapes from the fiber-containing material during pressing, and wherein the elevations form at least one pattern along a surface of the molded part.
2. The molded part according to
3. The molded part according to
4. The molded part according to
5. The molded part according to
6. The molded part according to
7. The molded part according to
8. The molded part according to
9. The molded part according to
10. The molded part according to
11. A molding tool for producing molded parts from fiber-containing material, wherein the molding tool has at least one molding surface for pressing the fiber-containing material into a three-dimensional molded body, wherein the at least one molding surface has openings for discharging steam from the fiber-containing material during a pressing process, and wherein the openings are arranged in a form of a pattern.