Device and method for laminating molded fiber parts

Abstract

The invention relates to a device (1, 21, 22) for laminating molded fiber parts (2) with a thermoplastic film (3), comprising a molding tool (4) having at least one mold cavity (5) for receiving a molded fiber part (2), and a forming tool (6) having at least one pre-stretching punch (8) and at least one heating device (15), wherein the molding tool (4) and the heating device (15) can be moved relative to one another from a spaced-apart position for receiving the plastic film (3) and / or delivering the laminated molded fiber part (7) into an approached position to form an at least substantially closed mold, wherein the pre-stretching punch (8) in the approached position can be moved from a retracted starting position into a pre-stretching position pre-stretching the plastic film (3) and back, wherein the heating device (15) is provided for heating at least two forming heating surfaces (13, 14) of the forming tool (6), wherein a forming heating surface (14) is provided on a free end of the pre-stretching punch (8) coming into contact with the plastic film (3) in the approached position at least during the pre-stretching of the plastic film (3), and wherein on the other side of the pre-stretching punch (8), preferably at least substantially circumferentially in relation to the pre-stretching punch (8), a forming heating surface (13) is provided for contact with the plastic film (3) in the approached position before the pre-stretching by the pre-stretching punch (8).

Description

[0001] September 23, 2025

[0002] Device and method for laminating fiber-molded parts

[0003] The invention relates to a device for laminating fiber-reinforced molded parts with a thermoplastic film. The invention further relates to a method for laminating fiber-reinforced molded parts with a thermoplastic film using such a device.

[0004] Fiber-based molded parts are typically used to create packaging and are increasingly replacing corresponding plastic packaging, which, depending on the application, can be produced in a wide variety of shapes using thermoforming machines. However, large quantities of such plastic packaging end up in the environment, where in most cases it is not biodegradable and is thus mechanically broken down over time into unwanted microplastics. To avoid this, packaging made from biodegradable, especially renewable, fibers such as paper or cardboard is increasingly being used. These fibers are coated as needed to provide sufficient moisture resistance and suitability for food packaging.

[0005] The coating can be applied in various ways. For example, the previously manufactured fiber molded parts can be sprayed with a liquid or suspension which, after drying, forms a water-repellent or even waterproof coating on the fiber molded part. It is also possible to cover the fiber molded parts with a plastic film. Depending on the shape of the fiber molded parts, however, this film must first be heated so that it can be applied to the entire surface. This process is also referred to as laminating the previously manufactured fiber molded parts. However, such packaging is complex to manufacture. This is especially true for packaging that is at least partially conical in shape for stacking. This is particularly the case with packaging in the form of cups and similar containers.Stackable packaging often has a considerable depth relative to the opening or base cross-section, which is inherently detrimental to lamination. Laminating such fiber-reinforced molded parts with a very thin plastic film is extremely difficult or even impossible, as the film lacks sufficient elasticity during the lamination process to adhere to the fiber-reinforced parts undamaged, across the entire surface, and permanently. This can be mitigated by using thicker plastic films for lamination, but this increases material costs. Furthermore, special care is required for fiber-reinforced molded parts made from nonwoven materials, such as cellulose fiber fleece, as the mechanical strength of such materials can be significantly reduced by moisture penetration.

[0006] Therefore, the present invention is based on the objective of designing and further developing the device and method of the type mentioned at the outset and explained in more detail above in such a way that packaging can be manufactured more easily and cost-effectively.

[0007] This problem is solved according to claim 1 by a device for laminating fiber-molded parts with a thermoplastic film, comprising a molding tool having at least one cavity for receiving a fiber-molded part and a forming tool having at least one pre-stretching die and at least one heating device, wherein the molding tool and the heating device are adjustable relative to each other from a spaced-apart position for receiving the plastic film and / or dispensing the laminated fiber-molded part to an approximate position for forming an at least substantially closed shape, wherein the pre-stretching die in the approximate position extends from a retracted initial position to a position extending the plastic film.

[0008] KJ / KJ 240336WO

[0009] September 23, 2025, adjustable to pre-stretch position and back, wherein the heating device is provided for heating at least two forming heating surfaces of the forming tool, wherein a forming heating surface is provided at a free end of the pre-stretch punch that comes into contact with the plastic film in the approximate position at least during pre-stretching of the plastic film, and wherein, beyond the pre-stretch punch, preferably at least substantially circumferentially to the pre-stretch punch, a forming heating surface is provided for contact with the plastic film in the approximate position before pre-stretching by the pre-stretch punch.

[0010] Furthermore, the aforementioned problem according to claim 11 is solved by a method for laminating fiber-molded parts with a thermoplastic film using a device according to any one of claims 1 to 10,

[0011] - in which, in the spaced-apart position of the forming tool and the forming tool, at least one fiber-shaped part is inserted into a mold cavity of the forming tool and a plastic film, preferably a blank of a plastic film, is provided at least partially between the forming tool and the forming tool,

[0012] - in which the forming tool and the forming tool are adjusted to the approximate position,

[0013] - in which, in the approximate position, the plastic film is heated by at least one forming heating surface beyond the pre-stretching die,

[0014] - in which, after heating, the plastic film is pre-stretched into the corresponding forming cavity from the initial position to the pre-stretch position beyond the pre-stretching die by adjusting the pre-stretching die with heated forming heating surface and

[0015] - in which the heated plastic film is laminated onto the fiber molded part in the mold cavity by overpressure on the side of the plastic film facing away from the fiber molded part and / or underpressure on the side of the plastic film facing the fiber molded part.

[0016] KJ / KJ 240336WO

[0017] September 23, 2025. The device is used for laminating fiber-reinforced molded parts with a thermoplastic film to prevent moisture from penetrating the fiber-reinforced molded parts through the laminated surface. For this purpose, the device has a molding tool with one or more cavities. A fiber-reinforced molded part can be inserted into one or more cavities. The plastic film can then be laminated onto the exposed inner surface of the fiber-reinforced molded part using a forming tool. The plastic film can be fed in as a continuous strip or as a blank. If a blank is used and the mold has multiple cavities, a single blank can be fed for all cavities. Alternatively, a separate blank can be fed for each cavity.

[0018] The forming tool comprises at least one pre-stretching die and at least one heating element. The number of pre-stretching dies preferably corresponds to the number of mold cavities in the forming tool, with one pre-stretching die assigned to each mold cavity. One heating element may suffice even in the case of multiple mold cavities. Alternatively, each mold cavity in the forming tool may have its own heating element. The forming tool and the forming tool are coupled in such a way that they can be adjusted from a spaced-apart position to a position closer together. In the spaced-apart position, for example, the plastic film and the fiber-reinforced molded parts can be fed in. The fiber-reinforced molded parts are inserted into the corresponding mold cavity of the forming tool. Alternatively or additionally, the laminated fiber-reinforced molded parts can be removed from the forming tool in the spaced-apart position.This is preferably done before feeding in new fiber-based molded parts. The forming tool can be designed as a so-called hold-down device for pressing the plastic film against the molding tool and / or the fiber-based molded part, as is generally used in thermoforming machines.

[0019] KJ / KJ 240336WO

[0020] September 23, 2025. In the approximate configuration, the mold and the forming tool form a mold that is at least substantially closed, comprising a plurality of individual molds in the case of multiple mold cavities, with each mold cavity then being part of a separate mold. The mold can be completely closed to the extent that the plastic film it contains can be subjected to overpressure or underpressure for lamination, for example, to conform fully to the fiber-reinforced molded part in the desired areas. Alternatively or additionally, the mold can also be closed to the extent that the forming tool presses the plastic film section by section against the fiber-reinforced molded part within the mold to bond the plastic film to the fiber-reinforced molded part in that section.In this context, it may be advantageous if the plastic film is pressed against the fiber molded part by a section of the forming tool heated by the heating device, in particular against an edge of the fiber molded part.

[0021] The pre-stretching die assigned to the mold cavity, or to the respective mold cavity of the forming tool, can be moved from a retracted initial position towards the mold cavity, at least when the plastic film is heated and the forming tool and die are in close proximity, into a so-called pre-stretching position. For simplicity, the other parts of the forming tool can remain stationary during this process. However, this is not mandatory. When the pre-stretching die is moved into the mold cavity, the plastic film is pre-stretched. By applying compressed air and / or a vacuum to the corresponding side of the plastic film, it can be pressed and / or drawn against the fiber-retained part held in the mold cavity after pre-stretching, creating a strong, permanent bond between the plastic film and the fiber-retained part.

[0022] The forming tool comprises at least two different forming heating surfaces for heating the plastic film and for reliably forming it. These forming heating surfaces are supported by at least one

[0023] KJ / KJ 240336WO

[0024] September 23, 2025. The heating element of the forming tool is heated. For this purpose, a forming heating surface is provided on the pre-stretching die, or, in the case of multiple pre-stretching dies in the forming tool, on each pre-stretching die. The pre-stretching die comes into contact with this forming heating surface, at least during the pre-stretching of the plastic film into the corresponding forming cavity of the mold, and heats the plastic film so that it can be pre-stretched appropriately and subsequently laminated onto the corresponding fiber-reinforced molded part. This prevents undesirable cooling of the plastic film during lamination, i.e., during the forming process. This ensures that the plastic film can be processed reliably and does not tear, even with very thin wall thicknesses.It may be advantageous if the forming heating surface of the pre-stretching die is provided at least substantially across the entire surface of the free end of the pre-stretching die that comes into contact with the plastic film.

[0025] Beyond the respective pre-stretching die, at least one further forming heating surface is provided on the forming tool. "Beyond the pre-stretching die" in this context means that the forming heating surface is located on a different component of the forming tool than a pre-stretching die. This results in this forming heating surface only being in contact with the plastic film in certain sections during the pre-stretching process. This can apply, for example, to the edge of the plastic film that is laminated onto an edge of the fiber-reinforced molded part and is heated by the forming heating surface for this purpose. In principle, the forming heating surface beyond the pre-stretching die is designed to heat the plastic film over a large area before pre-stretching by the pre-stretching die, when the forming tool and the forming tool are in close proximity.The plastic film should be brought to a temperature that allows for suitable reshaping of the plastic film for the purpose of lamination before the actual reshaping of the plastic film begins.

[0026] KJ / KJ 240336WO

[0027] September 23, 2025. In many cases, it will be preferred if the forming heating surface is provided circumferentially and adjacent to the pre-stretching die beyond the pre-stretching die, and in particular adjacent to the forming heating surface of the pre-stretching die itself. However, several forming heating surfaces may also be provided circumferentially and adjacent to the pre-stretching die. The distances between these forming heating surfaces are preferably small. Furthermore, a certain distance between at least one forming heating surface beyond the pre-stretching die and the forming heating surface of the pre-stretching die, or between the pre-stretching die itself, may be acceptable. This distance should, however, be small enough to ensure sufficiently uniform heating of the plastic film before forming.The at least one heating element of the forming heating tool can also be configured to heat the forming heating surface of the pre-stretching die and the at least one forming heating surface beyond the pre-stretching die to different temperatures. The preferred temperatures depend, among other things, on the material of the plastic film, the thickness of the plastic film, and the shape of the fiber-based molded part.

[0028] Even in the case of molds with multiple cavities for different fiber-based molded parts, a single heating surface beyond the pre-stretch dies may suffice. However, as previously described, each cavity can also be assigned at least one heating surface beyond the pre-stretch dies. The aim here is to keep the equipment complexity to a minimum while still ensuring uniform and reliable heating of the plastic film parts to be laminated and formed. Alternatively, each cavity can be assigned at least one heating surface beyond the corresponding pre-stretch die. In this case, for example, excessive heating of the plastic film in the non-forming area between the cavities can be avoided.

[0029] In this process, at least one fiber-shaped part is placed into the at least one mold cavity in the spaced-apart position of the molding tool and the forming tool.

[0030] KJ / KJ 240336WO

[0031] The forming tool is introduced on September 23, 2025. The same applies to at least one plastic film or at least one blank of plastic film that is placed between the forming tool and the forming tool. In the case of forming tools with multiple cavities, a separate blank of plastic film can be assigned to each cavity. The forming tool and the forming tool are then moved into the approximate position in which the plastic film is heated by the at least one forming heating surface beyond the pre-stretching die. In most cases, it is preferred that the forming heating surface of the pre-stretching die, in the approximate position of the forming tool and forming tool, comes into contact with the plastic film or the blank of plastic film in order to heat the plastic film.Then the forming heating surface of the pre-stretching die and the at least one forming heating surface beyond the pre-stretching die can be arranged at least substantially in a common plane.

[0032] After the plastic film has been heated by the forming heating surface beyond the pre-stretching die and, if applicable, by the forming heating surface of the pre-stretching die itself, particularly to a specific temperature, the pre-stretching die is moved from its initial position into the pre-stretched position within the corresponding mold cavity. This pre-stretches the plastic film between the forming tool and the forming tool into the mold cavity. During this process, the plastic film comes into contact with the forming heating surface of the pre-stretching die, preventing or minimizing cooling. The heated plastic film can then be pressurized on the side facing away from the fiber-reinforced molded part. This pressure is intended to press the plastic film against the fiber-reinforced molded part, thus laminating it at the designated point.Alternatively or additionally, it is conceivable to use a vacuum to draw the plastic film onto the fiber molded part on the side facing the fiber molded part in the mold cavity in order to laminate the corresponding area of ​​the fiber molded part.

[0033] KJ / KJ 240336WO

[0034] September 23, 2025 In a first particularly preferred embodiment of the device, the approximate position of the molding tool and the forming tool is designed to press the plastic film, especially from the forming heating surface beyond the pre-stretching die, against the fiber molded part in the mold cavity. The corresponding section of the fiber molded part can thus be laminated simply and reliably.

[0035] To avoid heat losses and to make the lamination process more reliable and reproducible, a thermal insulation layer can be provided on the side of the forming heating surface of the pre-stretching die facing away from the plastic film and / or on at least one forming heating surface beyond the pre-stretching die.

[0036] The forming tool, particularly the forming heating surface beyond the pre-stretching die, may optionally be provided with openings connected to a pressure device for generating a vacuum and drawing the plastic film to the at least one forming heating surface beyond the pre-stretching die. Through these openings, the plastic film can thus be drawn to at least one forming heating surface beyond the pre-stretching die. This ensures large-area contact between the plastic film and the forming heating surface beyond the pre-stretching die. Heating is therefore not affected by any potential air gap between the plastic film and the forming tool, and the heating of the plastic film can be carried out very reliably and precisely.

[0037] In the forming tool, particularly in the forming heating surface beyond the pre-stretching punch, openings can alternatively or additionally be provided which are connected to a pressure device for generating overpressure. The overpressure allows the plastic film to be pressed against the fiber-reinforced part in the mold cavity and bonded to it. It is preferred if the

[0038] KJ / KJ 240336WO

[0039] September 23, 2025 Openings in the forming tool for providing the vacuum are at least partially the same openings for providing the positive pressure.

[0040] Regardless of the openings in the forming heating surface beyond the pre-stretching die, openings can alternatively or additionally be provided in the forming heating surface of the pre-stretching die itself. These openings in the forming heating surface of the pre-stretching die are then preferably connected to at least one pressure device. A vacuum can be generated via the pressure device and the openings, if required, to draw the plastic film against the forming heating surface of the pre-stretching die. This achieves a large-area contact between the plastic film and the forming heating surface of the pre-stretching die and prevents the heating process from being impaired by a potential air gap between the plastic film and the pre-stretching die. The heating of the plastic film can thus be carried out very reliably and precisely.

[0041] The forming heating surface of the pre-stretching die can alternatively or additionally be provided with openings connected to at least one pressure device for generating overpressure in the mold cavity. These openings can be the aforementioned openings or, at least partially, other openings. The overpressure can then be used to press the plastic film against the fiber-reinforced molded part in the mold cavity.

[0042] It can also be advantageous if an area of ​​the mold, bordering at least partially on the mold cavity, has openings for the escape and / or removal of air displaced by the plastic film from the mold cavity. The air can then preferably escape or be removed during the lamination of the fiber-reinforced molded part. If a vacuum is used to draw the plastic film onto the fiber-reinforced molded part, the vacuum can be provided via the openings. If positive pressure is used to press the plastic film onto the fiber-reinforced molded part, the displaced air on the other side of the plastic film can escape through the openings. Regardless of this...

[0043] KJ / KJ 240336WO

[0044] On September 23, 2025, it is advisable that the area of ​​the mold tool containing the openings, which borders at least partially on the mold cavity, be designed to be porous. This creates an open porosity that allows air to escape from the mold cavity. Regardless, openings or porosity in the mold tool adjacent to the mold cavity are particularly effective if the fiber-based molded part is at least partially permeable to air, thus allowing airflow out of the mold cavity.

[0045] For simple and reliable adjustment of the pre-stretching die, the die can be positioned adjacent to a pressure chamber connected to a pressure device. The pre-stretching die can then be pneumatically or hydraulically adjusted from its initial position to the pre-stretched position and / or vice versa by means of the pressure chamber. For example, overpressure in the pressure chamber can move the pre-stretching die from its initial position to the pre-stretched position. Alternatively or additionally, overpressure in the same or another pressure chamber can move the pre-stretching die back from the pre-stretched position to its initial position. For this purpose, the overpressure applied to the plastic film during lamination can be used, for example.In this context, it is particularly advantageous to use a spring mechanism that, by means of a restoring force, returns the pre-extensioning piston from the pre-extensioned position to its initial position. However, the pre-extensioning piston can also be moved pneumatically or hydraulically from its initial position to the pre-extensioned position against the restoring force of the spring mechanism.

[0046] The mold can be designed to be heated adjacent to the mold cavity for receiving the fiber-reinforced part. This allows the fiber-reinforced part and the plastic film to have similar temperatures, which facilitates reliable lamination. It can be advantageous to heat different areas of the fiber-reinforced part to varying degrees. For this purpose, the mold can be designed to be heated adjacent to different areas of the

[0047] KJ / KJ 240336WO

[0048] September 23, 2025 The mold cavity for receiving the fiber molded part must be designed to be heated to different operating temperatures.

[0049] The differently heated areas of the mold adjacent to the mold cavity can have operating temperature differences of at least 10 °C, preferably at least 20 °C, and particularly at least 30 °C. To precisely set and maintain these temperature differences, it may be advantageous to provide a suitable control device. Alternatively or additionally, insulation can be provided, at least in sections, between the areas of the mold heated to different temperatures. This makes it easier to maintain the desired temperature difference between the areas.

[0050] If the forming tool has multiple cavities, each designed to hold a fiber-reinforced molded part, each cavity can be assigned a pre-stretching die with a forming heating surface on the forming tool. Furthermore, each cavity can be assigned at least one forming heating surface beyond the pre-stretching die on the forming tool. The forming tool and the forming tool can then be positioned to form multiple, at least substantially closed shapes, each assigned to a specific cavity. This allows several fiber-reinforced molded parts to be laminated in a single work cycle using one forming tool and one forming tool, thus reducing the cost of lamination and consequently the number of laminated fiber-reinforced molded parts.

[0051] In a first particularly preferred embodiment of the method, the plastic film, in the approximate position of the forming tool and the forming tool, is drawn by means of negative pressure to at least one forming heating surface beyond the pre-stretching die for heating. In this way, the plastic film can be heated reliably, precisely, and reproducibly.

[0052] KJ / KJ 240336WO

[0053] September 23, 2025 If, in the approximate position of the forming tool and the forming tool, the plastic film is heated by the at least one forming heating surface beyond the pre-stretching punch and simultaneously by the forming heating surface of the pre-stretching punch, a particularly uniform heating and thus a preferred forming of the plastic film is possible.

[0054] When the heated plastic film, in the approximate position of the forming tool and the forming die, is pressed section by section by the forming die against the fiber part held in the forming die, the corresponding area of ​​the fiber part can be easily laminated with the plastic film. This is particularly the case when the plastic film is pressed against the fiber part by at least one forming heating surface beyond the pre-stretching die, for example, against an edge of the fiber part.

[0055] When laminating the plastic film onto the fiber-reinforced molded part, air can be displaced from the mold cavity by the appropriately shaped plastic film. Preferably, this air is drawn out of the mold cavity and / or allowed to escape through openings in the mold during lamination. The air can initially pass through the fiber-reinforced molded part itself.

[0056] Alternatively or additionally, the pre-stretching ram can be pneumatically or hydraulically moved from the initial position to the pre-stretching position and / or from the pre-stretching position to the initial position. This can simplify the execution of the procedure, particularly with a simplified apparatus.

[0057] The mold can be heated adjacent to the fiber-reinforced part held in the mold cavity, if required. The heated mold then warms the fiber-reinforced part held in the mold cavity for more reliable lamination of the fiber-reinforced part with the also heated plastic film.

[0058] KJ / KJ 240336WO

[0059] September 23, 2025 In this context, it can contribute to preferential results if different areas of the mold adjacent to the fiber-shaped part held in the mold cavity are heated to different operating temperatures. It is then typically advantageous if a lower section of the fiber-shaped part or the mold cavity is heated to a higher temperature than an upper section of the fiber-shaped part or the mold cavity.

[0060] The invention will now be explained with reference to a drawing that merely illustrates exemplary embodiments. The drawing shows

[0061] Fig. 1 shows a first device according to the invention for laminating fiber molded parts in a schematic, perspective view,

[0062] Fig. 2A-C shows a detail of the device from Fig. 1 in different states during the lamination of the fiber molded part in a schematic sectional view.

[0063] Fig. 3 shows a detail of a second device according to the invention for laminating fiber molded parts in a schematic, perspective view and

[0064] Fig. 4 shows a detail of a third device according to the invention for laminating fiber molded parts in a schematic, perspective view.

[0065] Figure 1 shows a device 1 for laminating fiber-based molded parts 2 with a thermoplastic film 3. The device 1 comprises a molding tool 4 with a series of mold cavities 5, each of which holds a separate fiber-based molded part 2. The mold cavities 5 have an inner contour that corresponds at least substantially to the outer contour of the fiber-based molded part.

[0066] KJ / KJ 240336WO

[0067] September 23, 2025. The device 1 further comprises a forming tool 6, which, together with the forming tool 4, can be alternately adjusted from the depicted, defective position to an approximate position and back again. The forming tool 6 can be designed in the form of a so-called hold-down for pressing the plastic film 3 against the forming tool 4 and / or the fiber-shaped part 2. In the depicted, spaced-apart position, the already laminated fiber-shaped parts 7 can be removed from the mold cavities 5, and fiber-shaped parts 2 intended for lamination can be inserted into the mold cavities 5 for lamination. In addition, a plastic film 3 can be inserted into the space between the forming tool 4 and the forming tool 6. The plastic film 3 is always arranged between the fiber-shaped part 2 and the forming tool 6.

[0068] This arrangement is essentially maintained even when the forming tool 4 and the forming tool 6 are moved into an approximate position. In this approximate position, the forming tool 4 and the forming tool 6 form a plurality of separate, at least substantially closed, molds, each encompassing one of the mold cavities 5 of the forming tool 4. The plastic film 3 is initially positioned between the 6 mold halves formed by the forming tool 4 and the forming tool and can be pre-stretched by the pre-stretching dies 8 assigned to the mold cavities 5.

[0069] The plastic film 3 of the present embodiment is a thermoplastic film, in particular with a thickness of no more than 200 pm. The plastic film 3 can be unwound almost continuously from a roll. However, the plastic film 3 can also be supplied as at least one blank. With the plastic film 3 in the form of a single blank, all mold cavities 5 of the mold 4 can be covered together. It is also conceivable, however, that each mold cavity 5 of the mold 4 is covered with a separate blank of plastic film 3. In the latter case, waste can be avoided. Blanks can be produced from a continuous web of the plastic film 3. It can also be provided that the blanks of the

[0070] KJ / KJ 240336WO

[0071] On September 23, 2025, plastic film 3 will be provided via a magazine. Where and how the cut pieces of plastic film 3 are produced and transferred to the magazine is then of secondary importance.

[0072] Figures 2A-C show a detail of the device 1 in the area of ​​a mold cavity 5 of the molding tool 4 and the forming tool 6 in an approximate position, specifically during different phases of the lamination of the fiber-reinforced molded part 2. The corresponding areas of the various mold cavities 5 of the device 1 do not differ from each other or only differ slightly. It is also conceivable that the molding tool 4 is equipped with only one mold cavity 5 and that the forming tool 6 is intended for laminating only one fiber-reinforced molded part 2 in a single work cycle. In this case as well, the device 1 can be configured as shown in Figures 2A-C.

[0073] The mold 4 has the mold cavity 5 into which a correspondingly shaped fiber mold part 2 is inserted. The fiber mold part 2 can be made of a nonwoven fiber material, such as a nonwoven fabric made of cellulose fibers. However, fiber mold parts 2 made of other fiber materials are also possible, with fiber mold parts 2 made from renewable raw materials being preferred from an environmental perspective.

[0074] In the illustrated and preferred device 1, the mold 4 has two distinct sections 9 and 10. The lower section 9 of the mold 4 receives the base of the fiber-molded part 2 and is heated to a higher temperature, here approximately 100°C, than the upper section 10 of the mold 4. In the illustrated and preferred device 1, the upper section 10 of the mold 4 is heated to only approximately 70°C. The corresponding temperatures are set by a control device, which is not shown in detail. To reduce undesirable heat exchange between the lower section 9 and the upper section 10 of the mold 4, a [missing information - likely a specific component] is provided between the lower section 9 and the upper section 10 of the mold 4.

[0075] KJ / KJ 240336WO

[0076] September 23, 2025 Section 9 of the mold 4 and the upper section 10 of the mold

[0077] 4 an insulation 11 is provided. In the illustrated and thus preferred device, however, this does not extend completely to the mold cavity.

[0078] Figure 2A shows that the plastic film 3 is initially placed on the fiber-shaped part 2, which is held in the mold cavity 5. The forming tool 6 presses the film against the upper edge of the fiber-shaped part 2. The pre-stretching punch 8, which is associated with the mold cavity, is located in the forming tool 6 approximately in the middle of the cross-section of the mold cavity 5. The pre-stretching punch 8 can be moved from the initial position shown in Figure 2A to a pre-stretching position shown in Figure 2B and back again. When the pre-stretching punch 8 is moved to the pre-stretching position, the pre-stretching punch 8, and thus also the plastic film 3, is extended towards the mold cavity.

[0079] 5 is inserted. The plastic film 3 is thereby stretched or lengthened section by section. In this context, one also speaks of pre-stretching the plastic film 3 by the pre-stretching die 8.

[0080] Subsequently or concurrently, air can be drawn out of the mold cavity 5 via the lower section 9 of the molding tool 4, so that the plastic film 3, after pre-stretching by the pre-stretching punch 8, expands further due to the resulting vacuum and is drawn from the inside against the fiber molded part 2, as shown in Fig. 2C. To draw the air out of the mold cavity 5, the lower section 9 of the molding tool 4 is designed to be open and porous. The air can be drawn out of the mold cavity 5 through the fiber molded part 2 via the porosity of the lower section 9.

[0081] Alternatively or in addition to drawing air out of the mold cavity 5 via the forming tool 4, an overpressure can also be generated in the mold cavity 5 via the forming tool 6. This is achieved through openings 12 in the forming tool 6, in particular in the forming heating surface 14 of the pre-stretching punch 8 and in the forming heating surface 13 beyond the pre-stretching punch 8, and an associated

[0082] KJ / KJ 240336WO

[0083] On September 23, 2025, the pressure device 20 can pressurize the plastic film 3 so that the overpressure presses the pre-stretched plastic film 3 against the fiber molded part 2 from the inside, thus laminating the fiber molded part 2, as shown in Fig. 2C. Air is displaced from the mold cavity 5, which can escape from the mold cavity 5 through openings or a corresponding porosity in the lower section 9 of the molding tool 4.

[0084] The same openings 12 or other openings in the forming tool 6, in particular in the forming heating surface 14 of the pre-stretching punch 8 and in the forming heating surface 13 beyond the pre-stretching punch 8, can also be used to draw out air and thus draw the plastic film 3 against the forming tool 6, in particular against the forming heating surface 14 of the pre-stretching punch 8 and against the forming heating surface 13 beyond the pre-stretching punch 8. This ensures that the plastic film 3 is in contact with the forming tool 6, in particular against the forming heating surface 14 of the pre-stretching punch 8 and against the forming heating surface 13 beyond the pre-stretching punch 8, at least substantially over its entire surface. The openings 12 are provided at least in particular in a forming heating surface 13 beyond the pre-stretching die 8, so that the plastic film 3 has a planar contact with the forming heating surface 13 beyond the pre-stretching die 8 and can therefore be heated very precisely and evenly.

[0085] Through the openings 12 in the forming heating surface 14 of the pre-stretching die 8 on the one hand, and in the forming heating surface 13 beyond the pre-stretching die 8 on the other hand, a negative pressure or a positive pressure can be generated independently of one another via the at least one connected pressure device 20. The positive pressure and / or the negative pressure can vary accordingly. In particular, a negative pressure or a positive pressure, which may vary as required, can be applied to the forming heating surface 14 of the pre-stretching die 8 on the one hand and to the forming heating surface 13 beyond the pre-stretching die 8 on the other hand at different times, and possibly with different positive pressures as required. For example, a negative pressure can first be applied through the openings 12 in the forming heating surface 13 beyond the

[0086] KJ / KJ 240336WO

[0087] On September 23, 2025, an overpressure is generated by the pre-stretching die 8, while an overpressure is only subsequently generated via the openings 12 in the forming heating surface 14 of the pre-stretching die 8. If necessary, an underpressure can even be provided beforehand via the openings 12 in the forming heating surface 14 of the pre-stretching die 8. Then the pre-stretching die 8 continues to heat the plastic film 3, while the plastic film 3 is already being pressed by the overpressure towards the fiber-shaped part 2 at another point.

[0088] Regardless, in the illustrated and thus preferred device 1, it is also possible to heat the forming heating surface 14 of the pre-stretching die 8 and the forming heating surface 13 beyond the pre-stretching die 8 simultaneously or sequentially to different temperatures. Then the corresponding plastic film 3 can always be heated appropriately.

[0089] In the depicted and thus preferred forming tool 6, the plastic film 3 comes into planar contact with a forming heating surface 13 beyond the pre-stretching die 8 and with a forming heating surface 14 at the free lower end of the pre-stretching die 8. The heating of the plastic film 3 can therefore be even more uniform. The different forming heating surfaces 13, 14 are heated by a common heating device 15 of the forming tool 6. However, it would also be conceivable if the different forming heating surfaces 13, 14 were heated by separate heating devices 15. An insulating layer 16 is provided on the side of the forming heating surfaces 13, 14 facing away from the plastic film 3. During pre-stretching, the plastic film 3 remains in contact with the forming heating surface 14 of the pre-stretching die 8.The forming heating surface 14 at the free lower end of the pre-stretching die 8 is preferably heated further, while the forming heating surface 13 beyond the pre-stretching die 8 may no longer need to be heated, since the plastic film 3 then only makes minimal contact with the forming heating surface 13 beyond the pre-stretching die 8.

[0090] KJ / KJ 240336WO

[0091] September 23, 2025. The pre-stretching plunger 8, acting like a piston, borders two pressure chambers 17 and 18, against which the pre-stretching plunger 8 is sealed. When the first pressure chamber 17 is pressurized, the pre-stretching plunger 8 moves from its initial position to the pre-stretched position. Conversely, when the second pressure chamber 18 is pressurized, the pre-stretching plunger 8 moves back from the pre-stretched position to its initial position. A spring element 19 can also be provided in the second pressure chamber 18 to assist the return of the pre-stretching plunger 8. Alternatively, the second pressure chamber 18 need not be designed as a pressure chamber. It may be sufficient if the spring element 19 is provided in the second chamber.

[0092] It is not shown in detail that the forming tool 4 and the forming tool 6 interact in such a way that the fiber-based molded part 2 or the laminated fiber-based molded part 7 is trimmed or punched so that the edge of the laminated fiber-based molded part 7 has a predetermined dimension. This can be done while the fiber-based molded part 2 is held in the molded part cavity 5. The forming tool 4 can then have a cutting edge, in particular a circumferential one, which can be pressed against a stop surface of the forming tool 6 in such a way that the excess parts of the fiber-based molded part 2 are cut off. Alternatively or additionally, the forming tool 6 can also have such a cutting edge, which can be pressed against a stop surface of the forming tool 4. In such a case, no further cutting or punching station is required for trimming the fiber-based molded part 2. However, such a station can still be provided if necessary.Then, for example, the laminated fiber molded part 2 is removed from the molding tool 4 and transferred to a cutting or punching station where the laminated fiber molded part 7 is trimmed.

[0093] Figure 3 shows a detail of an alternative device 21 for laminating fiber-molded parts 2 or an alternative method for laminating fiber-molded parts 2. Devices 1 and 21 are of the same design, therefore similar components are assigned the same reference numerals.

[0094] KJ / KJ 240336WO

[0095] On September 23, 2025, in the illustrated, approximate position of forming tool 6 and forming tool 4 with the pre-stretching punch 8 in a starting position, the pre-stretching punch 8, with its forming heating surface 14, projects slightly downwards into the forming cavity 5 relative to the forming heating surface 13 beyond the pre-stretching punch 8. This ensures that the plastic film 3, which is drawn in through the openings 12 in the forming heating surface 14 of the pre-stretching punch 8 and in the forming heating surface 13 beyond the pre-stretching punch 8, rests against the outer radius at the free end of the pre-stretching punch 8. Consequently, the section of the plastic film 3 not directly in contact with a forming heating surface 13, 14 is smaller than in the device 1 in the embodiment according to Fig. 2A.In a preferred embodiment of the method, the pre-stretching punch 8 can be moved downwards during the heating of the plastic film, so that it then projects beyond the forming heating surface 13. The pre-stretching punch 8 can be subjected to a predetermined travel profile into the forming cavity 5. This travel profile can move the pre-stretching punch 8 from the position shown in Fig. 3 further into the pre-stretched position in a predetermined manner.

[0096] Figure 4 shows a detail of another device 22 for laminating fiber-based molded parts 2 or an alternative method for laminating fiber-based molded parts 2. Devices 1, 21, and 22 are of identical design, which is why similar components are assigned the same reference numerals. In Figure 4, in the approximate position of forming tool 6 and molding tool 4 shown, the pre-stretching punch 8 is arranged in the pre-stretch position, in which the pre-stretching punch 8 is inserted into the mold cavity 5 towards the fiber-based molded part 2 to such an extent that the free end of the pre-stretching punch 8 presses the adjacent section of the plastic film 3 against the inside of the fiber-based molded part 2 to facilitate the lamination of the fiber-based molded part 2 with the plastic film 3.

[0097] KJ / KJ 240336WO

[0098] September 23, 2025 Reference List

[0099] 1 Device

[0100] 2 Fiber molded part

[0101] 3 plastic film

[0102] 4 Forming tool

[0103] 5 Form cavity

[0104] 6 Forming tool

[0105] 7 laminated fiber molded part

[0106] 8 Pre-stretching stamps

[0107] 9 lower section

[0108] 10 upper section

[0109] 11 Insulation

[0110] 12 openings

[0111] 13 Forming heating surface

[0112] 14 Forming heating surface

[0113] 15 Heating system

[0114] 16 Insulation layer

[0115] 17 Printing room

[0116] 18 Printing room

[0117] 19 Spring elements

[0118] 20 Printing device

[0119] 21 Device

[0120] 22 Device

[0121] KJ / KJ 240336WO

[0122] September 23, 2025

Claims

23. September 2025 P a t e n t a n s p r ü c h e 1. Device (1, 21, 22) for laminating fiber-based molded parts (2) with a thermoplastic film (3), comprising a molding tool (4) having at least one mold cavity (5) for receiving a fiber-based molded part (2) and a forming tool (6) having at least one pre-stretching die (8) and at least one heating device (15), wherein the molding tool (4) and the heating device (15) are adjustable relative to each other from a spaced-apart position for receiving the plastic film (3) and / or dispensing the laminated fiber-based molded part (7) to an approximate position for forming an at least substantially closed shape, wherein the pre-stretching die (8) in the approximate position is adjustable from a retracted initial position to a pre-stretching position extending the plastic film (3) and back, wherein the heating device (15) is provided for heating at least two forming heating surfaces (13, 14) of the forming tool (6),wherein a forming heating surface (14) is provided at a free end of the pre-stretching die (8) which comes into contact with the plastic film (3) in the approximate position at least during the pre-stretching of the plastic film (3), and wherein beyond the pre-stretching die (8), preferably at least substantially circumferentially to the pre-stretching die (8), a forming heating surface (13) is provided for contact with the plastic film (3) in the approximate position before pre-stretching by the pre-stretching die (8).

2. Device according to claim 1, characterized in that the approximate position of the forming tool (4) and the forming tool (6) is designed to protect the plastic film (3), in particular from the forming heating surface. (13) beyond the pre-stretching punch (8), to press against the fiber molded part (2) in the mold cavity (5).

3. Device according to claim 1 or 2, characterized in that a thermal insulation layer (16) is provided on the side of the forming heating surface (14) of the pre-stretching die (8) facing away from the plastic film (3) and / or the forming heating surface (13) beyond the pre-stretching die (8).

4. Device according to one of claims 1 to 3, characterized in that openings (12) are provided in the forming heating surface (13) beyond the pre-stretching die (8) and that the openings (12) in the forming heating surface (13) beyond the pre-stretching die (8) are connected to a pressure device (20) for generating a vacuum and drawing the plastic film (3) onto the forming heating surface beyond the pre-stretching die (8).

5. Device according to one of claims 1 to 4, characterized in that openings (12) are provided in the forming heating surface (13) beyond the pre-stretching die (8) and that the openings (12) in the forming heating surface (13) beyond the pre-stretching die (8) are connected to a pressure device (20) for generating an overpressure and pressing the plastic film (3) against the fiber molded part (2) in the mold cavity (5).

6. Device according to one of claims 1 to 5, characterized in that openings (12) are provided in the forming heating surface (14) of the pre-stretching die (8) and that the openings (12) in the forming heating surface (14) of the pre-stretching die (8) are equipped with a pressure device (20) for generating a KJ / KJ 240336WO September 23, 2025 The vacuum and suction of the plastic film (3) to the forming heating surface (14) of the pre-stretching punch (8) are connected.

7. Device according to one of claims 1 to 6, characterized in that openings (12) are provided in the forming heating surface (14) of the pre-stretching die (8) and that the openings (12) in the forming heating surface (14) of the pre-stretching die (8) are connected to a pressure device (20) for generating an overpressure and pressing the plastic film (3) against the fiber molded part (2) in the mold cavity (5).

8. Device according to one of claims 1 to 7, characterized in that the forming tool (4) adjacent to the forming cavity (5) for receiving the fiber forming part (2) can be heated and that, preferably, the forming tool (4) adjacent to different areas of the forming cavity (5) for receiving the fiber forming part (2) can be heated to different operating temperatures.

9. Device according to claim 8, characterized in that a control device is provided to provide a difference in operating temperatures of at least 10 °C, preferably at least 20 °C, in particular at least 30 °C, between the different areas adjacent to the mold cavity (5) and / or that thermal insulation (11) is provided at least sectionally between the two areas to be heated to different operating temperatures.

10. Device according to one of claims 1 to 9, characterized in that the forming tool (4) has a plurality of forming cavities (5) for receiving one fiber forming part (2) each and the forming tool (6) of each KJ / KJ 240336WO September 23, 2025 a pre-stretching die (8) with a forming heating surface (14) and a forming heating surface (13) arranged beyond the pre-stretching die (8) is assigned to the forming cavity (5), and the forming tool (4) and the forming tool (6) are provided in the approximate position to form a plurality of at least substantially closed forms, each assigned to a forming cavity (5).

11. Method for laminating fiber-molded parts (2) with a thermoplastic film (3) using a device (1, 21, 22) according to any one of claims 1 to 10, wherein, in the spaced-apart position of the molding tool (4) and the forming tool (6), at least one fiber-molded part (2) is inserted into a mold cavity (5) of the molding tool (4) and a plastic film (3), preferably a blank of a plastic film (3), is provided at least partially between the molding tool (4) and the forming tool (6), wherein the molding tool (4) and the forming tool (6) are adjusted to the approximate position, wherein, in the approximate position, the plastic film (3) is heated by the at least one forming heating surface (13) beyond the pre-stretching die (8),in which the plastic film (3), after being heated by the forming heating surface (13), is pre-stretched from the initial position into the pre-stretch position into the associated mold cavity (5) beyond the pre-stretching die (8) by adjusting the pre-stretching die (8) with heated forming heating surface (14), and in which the heated plastic film (3) is laminated onto the fiber mold part (2) in the mold cavity (5) by overpressure on the side of the plastic film (3) facing away from the fiber mold part (2) and / or underpressure on the side of the plastic film (3) facing the fiber mold part (2). KJ / KJ 240336WO September 23, 2025 12. Method according to claim 11, wherein in the approximate position the plastic film (3) is drawn to the forming heating surface (13) beyond the pre-stretching die (8) by means of a vacuum for heating and / or wherein in the approximate position the plastic film (3) is heated by the at least one forming heating surface (13) beyond the pre-stretching die (8) and simultaneously by the forming heating surface (14) of the pre-stretching die (8).

13. Method according to claim 11 or 12, wherein the overpressure is generated via openings (12) connected to at least one pressure device (20) in the at least one forming heating surface (13) beyond the pre-stretching die (8) and / or in the at least one forming heating surface (14) of the pre-stretching die (8) on the side of the plastic film (3) facing away from the fiber forming part (2) in the mold cavity and / or wherein the underpressure is generated via openings (12) connected to at least one pressure device (20) in the at least one forming heating surface (13) beyond the pre-stretching die (8) and / or in the at least one forming heating surface (14) of the pre-stretching die (8).

14. Method according to one of claims 11 to 13, wherein in the approximate position the heated plastic film (3) is pressed section by section against the fiber forming part (2) received in the forming tool (4) by the forming tool (6), in particular the forming heating surface (13) beyond the pre-stretching punch (8).

15. Method according to one of claims 11 to 14, wherein the molding tool (4) is heated adjacent to the fiber molded part (2) received in the mold cavity (5) and KJ / KJ 240336WO September 23, 2025 in which, preferably, different areas of the molding tool (4) adjacent to the fiber molded part (2) received in the mold cavity (5) are heated to different operating temperatures. KJ / KJ 240336WO September 23, 2025

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