Process for producing a decorated molded part

Abstract

The invention relates to a method for producing a decorated molded part (10), wherein the molded part (10) comprises a fiber mat (11) which comprises natural fibers and thermoplastic fibers, wherein in an upper boundary region (40) of the fiber mat (11) the natural fibers are at least partially decorated with a decorative layer (14) of a decorative web (12) and in a lower region (41) the thermoplastic fibers and a substrate (13) of the decorative web (12) are fused to form a composite.

Description

[0001] The invention relates to a method for producing a decorated molded part.

[0002] It is known to three-dimensionally deform natural fiber polypropylene fiber mats, also known as NFPP mats, particularly by thermoplastic deep drawing or "thermoforming." This involves first preparing an NFPP mat tailored to the component to be manufactured, which is then pressed into a planar shape in a so-called calibration press under pressure and heat. This so-called calibration process melts the thermoplastic matrix of the polypropylene fibers, making the NFPP mat deformable. The calibrated NFPP mat is then inserted into a three-dimensional mold and subsequently "cold-pressed" so that the NFPP mat adapts to the shape of the mold. Upon cooling, the previously melted thermoplastic matrix solidifies again, producing a three-dimensional component.The existing processes have the problem that only single-color components can be produced, with the color essentially determined by the color of the polypropylene fibers and natural fibers present in the NFPP mat. There are already processes in which carpets or leather are laminated onto the NFPP mat, but this results in the loss of the tactile feel and characteristic visual appearance of the fibers.

[0003] From DE 102011119248 A1 a fiber composite part and a corresponding manufacturing process are known in which a UV-ray reflecting mordant is applied to the fiber semi-finished product.

[0004] The invention is based on the object of specifying a method by means of which fiber mats, in particular NFPP mats, can be decorated in a variety of ways while retaining the feel and the characteristic optical appearance of the fiber mat.

[0005] This object is achieved by a method for producing a decorated molded part, wherein the molded part comprises a fiber mat which has natural fibers and thermoplastic fibers, wherein the method comprises the following steps, in particular in the following order: a) providing a decorative sheet, wherein the decorative sheet comprises a substrate and at least one decorative layer applied to the substrate; b) providing a fiber mat, wherein the fiber mat comprises natural fibers and thermoplastic fibers; c) inserting the fiber mat and the decorative web into a press, in particular into a calibration press, wherein the decorative web is arranged on the fiber mat such that the at least one decorative layer of the decorative web faces the fiber mat; d) pressing the fiber mat and the decorative sheet under thermal heating so that the substrate of the decorative sheet fuses with the thermoplastic fibers of the fiber mat and the decorative layer of the decorative sheet decorates the natural fibers arranged in an upper boundary region of the fiber mat to provide a decorated fiber mat; e) forming the decorated fiber mat in a mold to obtain a decorated molded part.

[0006] It has been shown that the method according to the invention for producing a decorated molded part produces a molded part in which the feel of the fiber mat and its characteristic visual appearance are retained, and the molded part has a visually appealing decoration. Such molded parts can be used, for example, as cockpit panels in vehicle construction and, due to the visually appealing decoration, can now also be used as a replacement for conventional cockpit elements made of plastic. Further advantageous embodiments of the invention are described in the subclaims.

[0007] The "visible side" refers to the side that is always visible to the observer after the decorated molding has been installed. This is usually the decorated side of the fiber mat or molding.

[0008] In this case, “back” or reverse side is understood to mean the side of the decorative sheet that faces the fiber mat when the decorative sheet is inserted into the press.

[0009] In this case, “front side” or front side is understood to mean the side of the decorative sheet that faces away from the fiber mat when the decorative sheet is inserted into the press.

[0010] The term “upper limit area” is understood to mean the area of the fiber mat or molded part that extends from the visible side of the fiber mat or molded part in the direction of the side of the fiber mat or molded part opposite the visible side.

[0011] The "lower area" is understood to be the opposite area of the upper limit area. This means that the lower area extends from the side facing away from the visible side toward the visible side and ends where the upper limit area ends. For example, if the upper limit area corresponds to 33% of the thickness of the fiber mat or molded part, then the lower area corresponds to 67% of the thickness of the fiber mat or molded part.

[0012] A transition zone may also develop between the upper and lower limits. In this transition zone, the natural fibers preferably exhibit only very light decoration, whereas in the upper limit, the decoration is ideally more pronounced.

[0013] “Registered” refers to the arrangement of one layer in relation to another layer or the structuring of a layer relative to another layer in a way that is accurate to register. Registered or register or accurate to register or register accuracy or register accuracy refers to the positional accuracy of two or more layers relative to one another. The register accuracy should be within a specified tolerance and as small as possible. At the same time, the register accuracy of several elements and / or layers in relation to one another is an important feature for increasing process reliability. Accurate positioning can be achieved in particular using sensory, preferably optically detectable, fiducials or register marks.These registration marks or register marks can either represent special separate elements or areas or layers or can themselves be part of the elements or areas or layers to be positioned.

[0014] "Degradable biopolymers" are preferably understood to mean plastics that decompose under certain conditions, producing carbon dioxide (CO2) or water (H2O) as the end product. For example, the degradable biopolymers can be made from thermoplastic starch, cellulose, and polylactide (PLA). Biopolymers are preferably made from renewable, particularly organic, raw materials, which include, in particular, starch- and cellulose-rich plants, such as corn, miscanthus, wood, or oilseeds.

[0015] It can preferably be provided that the fiber mat comprises essentially 50% natural fibers and 50% thermoplastic fibers, in particular that the fiber mat comprises at least 33% natural fibers and / or at least 33% thermoplastic fibers. In a preferred embodiment, it is provided that the fiber mat comprises half natural fibers and the other half thermoplastic fibers. Such a proportion of thermoplastic fibers ensures that the subsequent molded part has the necessary mechanical stability, in particular strength, for the predetermined intended use. This is preferably due to the fact that the thermoplastic fibers fuse to form a thermoplastic composite after pressing, and this composite hardens. The natural fibers, on the other hand, retain their original shape after pressing and thus ensure the characteristic feel and visual appearance of the fiber mat or molded part.

[0016] In particular, it is possible for the natural fiber to comprise a fiber type or mixture of fiber types selected from: hemp fiber, flax fiber, jute fiber, kenaf fiber, or coconut fiber. Such fibers are widely used industrially and are characterized by good material properties. In particular, the natural fiber cannot melt under the influence of temperature, in particular in a temperature range up to 300°C, particularly preferably up to 220°C. Preferably, the natural fiber is a non-melting fiber. This ensures that even during or after pressing the fiber mat, which takes place under the influence of heat or temperature, the natural fibers retain their characteristic feel and shape.

[0017] Furthermore, it is also possible for the thermoplastic fiber to comprise a material or combination of materials selected from: polypropylene (PP), polyethylene (PE), polyolefins, polyethylene terephthalate (PET), biodegradable biopolymers, in particular polylactide (PLA). Polypropylene in particular is particularly well suited for fiber production and can also be easily recycled. This means, for example, that the thermoplastic fibers can be made from recycled polypropylene or other polymers. For polypropylene fibers, for example, the melting point is an important factor. The melting temperature of the thermoplastic fibers or the polypropylene fiber determines the temperature at which the subsequent pressing or calibration of the fiber mat takes place. For example, isotactic polypropylene fibers have a melting point in the range of approximately 150°C to 170°C, and atactic polypropylene fibers have a melting point of approximately120°C to 140°C. This means that when using atactic polypropylene fibers, the fiber mat can be pressed or calibrated at lower temperatures, making it more energy-efficient.

[0018] Calibration refers to the pre-compression of the fiber mat. The calibration process can be applied to the fiber mat alone, or it can be applied to the fiber mat together with the decorative sheet, meaning that in this case, calibration can be applied to both the fiber mat and the decorative sheet simultaneously.

[0019] Fiber mats are also conceivable, which, in addition to natural and polymer fibers, also contain portions of inorganic materials, preferably glass fibers and / or carbon fibers. Such fibers or fiber mats further improve the mechanical stability and mechanical resilience of the fiber mat after processing.

[0020] The different fibers vary in their thickness and fiber length. The corresponding parameters for the different fiber types are shown in the table below: Fiber type Diameter (µm) length Fiber density (g / cm 3 ) Hemp fiber 16-50 Varies 1,48 - 1,51 flax fiber 12-30 Varies 1,5 - 1,6 Jute fiber 20-100 Varies 1,3 - 1,5 Kenaf fiber 15-40 Varies Varies Coconut fiber 100-400 Varies 1,15 - 1,4 PP fibers Varies Varies 0,89 -0,91

[0021] Depending on the fibers used, a different haptic and / or visual appearance can be achieved, which is also tactilely and / or visually perceptible to the consumer in the decorated molded part. For example, the fiber mat can be designed to contain hemp fibers and polypropylene fibers. However, all fiber materials with a matrix are possible.

[0022] The fiber mat represents the starting point for the production of the decorated molded part. In the subsequent molded part, the thermoplastic fibers are preferably no longer visible as such, as they plasticize through thermal heating and later solidify into a solid composite with the natural fibers. In particular, it is intended that the thermoplastic composite comprises a proportion of at least 33 vol.%, in particular of at least 50 vol.%, of the total volume of the decorated molded part. Such a proportion of the thermoplastic composite gives the molded part the necessary structural integrity, which, as a carrier matrix, in conjunction with the fibers, forms a corresponding composite that generates the necessary mechanical stability, in particular strength, required for the predetermined intended use of the molded part.

[0023] Preferably, the fiber mat, in particular the uncalibrated fiber mat, has a thickness in the range of 2 mm to 25 mm, in particular 6 mm to 15 mm, in step b). Typically, the fiber mat is provided wound on a roll. Before inserting the fiber mat into a press in step c), it is preferably provided that the fiber mat is cut accordingly, so that a finished fiber mat is preferably provided.

[0024] It may be possible for the substrate of the decorative sheet to comprise polypropylene (PP) as its material. It may also be possible for the substrate of the decorative sheet to comprise a material or combination of materials selected from: polypropylene (PP), polyethylene (PE), polyolefins, polyethylene terephthalate (PET), biodegradable biopolymers, in particular polylactide (PLA). It has been found that it is particularly advantageous if the substrate of the decorative sheet comprises a similar or the same material as the thermoplastic fibers of the fiber mat. This allows a homogeneous composite of the plastic mass, comprising the molten thermoplastic fibers and the material of the substrate of the decorative sheet, to form during the subsequent pressing of the fiber mat. A plastic mass that is as homogeneous as possible ensures that a homogeneous composite is created during the subsequent cooling process, which is particularly stable and break-resistant.

[0025] In particular, it is provided that in order to provide the decorative strip in step (a) the following steps are carried out, in particular in the order specified: - Providing the substrate; - Applying the decorative layer by printing and / or by transferring a transfer layer of a transfer film, in particular by hot stamping.

[0026] It is thus possible for the decorative layer to be formed from a combination of one or more printing layers and one or more transfer layers of a transfer film. It is also possible for the hot embossing to be arranged on one side of the substrate and the printing on the other side of the substrate. Alternatively, it is possible for the printing and hot embossing to be arranged on one side of the substrate. In particular, it is provided that the printing and hot embossing overlap and / or that the printing and hot embossing are arranged at a distance from one another. This makes it possible to realize a multitude of design variants. When the decorative layer is applied by printing, this is preferably done by means of a printing process, individually or in combination selected from: screen printing, gravure printing, digital printing, inkjet printing, laser printing. When a transfer layer of a transfer film is applied, the transfer layer of the transfer film preferably functions as the decorative layer.The transfer foil, in particular hot stamping foil, preferably comprises a carrier and a transfer layer that can be detached from the carrier by means of a release layer. This transfer layer can have at least one layer or a combination of several layers selected from: ink layer, metal layer, replication layer, protective lacquer layer, primer, adhesive layer, adhesion promoter layer, barrier layer, conductive layer, lacquer layer.

[0027] The application of the decorative layer can, for example, involve applying a transfer layer of a transfer film and subsequently overprinting the applied transfer layer on the substrate. For example, the transfer layer can comprise a metal layer, and the overprinting of the transfer layer can be carried out with one or more translucent ink layers.

[0028] It is particularly preferred that the decorative layer is formed from a metal layer or a color layer.

[0029] Preferably, it may be possible for the transfer layer to be transferred at least partially or over the entire surface onto the substrate of the decorative web by means of a hot stamping stamp and / or by means of a hot stamping wheel.

[0030] It is preferably provided that the decorative layer of the decorative web has at least one layer or combinations of several layers selected from: color layer, metal layer, replication layer, protective lacquer layer, primer, adhesive layer, adhesion promoter layer, barrier layer, conductive layer, lacquer layer.

[0031] In particular, it is provided that the decorative layer is designed as one or more motifs. A motif can be, for example, a graphically represented outline, a figurative representation, an image, a visually recognizable design element, a symbol, a logo, a portrait, a pattern, a continuous pattern, an alphanumeric character, a code, a code pattern, a cryptographic pattern, a text, a color design, and the like. The motif can also be customized. In particular, it is provided that the decorated area forms one or more motifs.

[0032] Furthermore, it can be provided that in step a), the decorative layer is applied to the front and / or back of the substrate. Advantageously, the decorative layer is applied to the back of the substrate. This allows for particularly effective decoration of the natural fibers. Surprisingly, it has been shown that when the decorative layer is applied to the back of the substrate, the decorative layer adheres extremely well to the fiber mat, particularly to the natural fibers of the fiber mat.

[0033] A carrier is preferably understood to mean a single-layer or multi-layer film, one or more layers of which comprise in particular the following materials or combinations: PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PEN (polyethylene naphthalate), PC (polycarbonate), PVC (polyvinyl chloride), Kapton (poly[N,N-(oxydiphenylene)pyromellitimide]) or other polyimides, PLA (polylactate), PMMA (polymethyl methacrylate) or ABS (acrylonitrile butadiene styrene).

[0034] The layer thickness of the carrier is in particular in a range from 1 µm to 500 µm, preferably from 6 µm to 100 µm, more preferably from 6 µm to 75 µm.

[0035] The carrier may have been subjected to a surface treatment, for example by means of plasma and / or corona, on one or both sides.

[0036] The carrier itself can have an adhesion promoter layer. This adhesion promoter layer is applied during the carrier manufacturing process. The layer thickness of the adhesion promoter layer of a carrier supplied by the carrier supplier is preferably in the range of 0.1 µm to 5 µm. The primer materials listed below can be used as the adhesion promoter layer.

[0037] A primer or adhesion promoter layer increases the adhesion between two layers that would otherwise lack sufficient adhesion to each other. For example, this can be the adhesion of the replication layer to the carrier. The primer or adhesion promoter layer preferably comprises a material or combinations thereof selected from: polyester, polyacrylate, polymethacrylate, polyurethane, polystyrene, polybutyrate, nitrocellulose, polyvinyl chloride, ethylene-vinyl acetate, their copolymers, or similar polymers or mixtures thereof. The primer or adhesion promoter layer can be thermoplastic, chemically crosslinkable, UV-curable, a hybrid variant (thermoplastic and UV-curable or / or crosslinkable by other means), a cold adhesive / primer, or a self-adhesive primer.

[0038] The primer or adhesion promoter layer preferably has a thickness in the range of 0.01 µm to 15 µm, preferably 0.1 µm to 5 µm. Inorganic materials such as metals, metal oxides, alloys, oxides, or silicates can also serve as adhesion promoters or be part of such a system.

[0039] The primer or adhesion promoter layer can also contain additives based on organic or inorganic substances that achieve a predetermined effect in the processing properties, for example, when applying a layer of transfer film. The proportion of additives in the total coating of the primer or adhesion promoter layer is usually between 0% and 10%, preferably between 0% and 5%, more preferably between 0.01 and 3%.

[0040] Furthermore, fillers can also be part of the formulation of a primer or adhesion promoter layer. This preferably includes all other materials added to a system, especially a polymer-based system, such as silica, pigments, dyes, tracers, especially taggants, and / or similar materials. The proportion of fillers in the total coating of the primer or adhesion promoter layer is usually between 0% and 80%.

[0041] In addition, primers or adhesion promoter layers can be formulated so that they remain tacky or even liquid even after the solvent has evaporated and / or before full curing. This is particularly advantageous when two substrates are to be bonded together over a large area, as is typically the case in a laminating process.

[0042] The release layer ensures, in particular, that the transfer layer of the transfer foil, in particular hot stamping foil, which is applied as a decorative layer to the substrate of the decorative web, can be non-destructively separated from the carrier as transfer layers. The release layer preferably comprises a material or combination of materials selected from: waxes, polyethylene (PE), polypropylene (PP), cellulose derivatives, and / or poly(organo)siloxanes. The aforementioned waxes can be natural waxes, synthetic waxes, or combinations thereof. The aforementioned waxes include, for example, carnauba waxes. The aforementioned cellulose derivatives include, for example, cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB), or mixtures thereof. The aforementioned poly(organo)siloxanes include, for example, silicone binders, polysiloxane binders, or mixtures thereof.The release layer preferably has a layer thickness in the range of 1 nm and 500 nm, in particular of 5 nm and 250 nm, preferably of 10 nm and 250 nm.

[0043] As already mentioned above, it is also possible for at least one decorative layer to be applied to the front side of the substrate of the decorative sheet. When applying the decorative layer to the front side, it is particularly intended that a protective lacquer layer is applied to the front side of the substrate in step a). This protective lacquer layer provides protection against mechanical or physical-chemical stress.

[0044] The protective coating layer is preferably a layer made of PMMA, PVC, melamine, and / or acrylates. The protective coating layer can also be made of a radiation-curing dual-cure coating. This dual-cure coating can be thermally pre-crosslinked in a first step during and / or after application in liquid form. Preferably, in a second step, particularly after processing the starting material or the multilayer body, the dual-cure coating is post-crosslinked radically, particularly via high-energy radiation, preferably UV radiation. Dual-cure coatings of this type can consist of various polymers or oligomers containing unsaturated acrylate or methacrylate groups. These functional groups can be radically crosslinked with one another, particularly in the second step.For thermal pre-crosslinking in the first step, it is advantageous that these polymers or oligomers also contain at least two or more alcohol groups. These alcohol groups can be crosslinked with multifunctional isocyanates or melamine-formaldehyde resins. Preferred unsaturated oligomers or polymers are various UV raw materials such as epoxy acrylates, polyether acrylates, polyester acrylates, and especially acrylate acrylates. Both blocked and unblocked versions based on TDI (TDI = toluene-2,4-diisocyanate), HDI (HDI = hexamethylene diisocyanate), or IPDI (IPDI = isophorone diisocyanate) can be used as the isocyanate. The melamine crosslinkers can be fully etherified versions, imino types, or benzoguanamine types.

[0045] The protective lacquer layer preferably has a layer thickness in the range of 50 nm to 50 µm, more preferably 1 µm to 30 µm. The protective lacquer layer can be produced or applied by gravure printing, flexographic printing, screen printing, inkjet printing, or by means of a slot nozzle and / or by vapor deposition, in particular by means of physical vapor deposition (PVD), chemical vapor deposition (CVD), and / or sputtering.

[0046] Preferably, the protective lacquer layer can be transparent or colored.

[0047] A replication layer is preferably understood here to be a special, functional layer into which structures, preferably optically variable structures, are introduced and / or fixed, in particular by means of thermal replication and / or UV replication using a replication tool. In the case of a hybrid replication layer, this is replicated thermally, for example, and subsequently cured by means of radiation, for example by means of UV radiation and / or at least one electron beam. In the case of a UV-curing replication layer, this is replicated at room temperature and simultaneously cured by means of radiation, for example by means of UV radiation and / or at least one electron beam. For example, it is possible that the varnish becomes warm during UV replication.

[0048] It is possible that the replication layer has a layer thickness in the range of 0.1 µm to 30 µm, in particular in the range of 0.5 µm to 10 µm.

[0049] Preferably, the at least one primer is an adhesive that preferably increases or improves adhesion to other layers. For example, to the substrate to which the transfer layer is to be applied as a decorative layer.

[0050] The at least one primer used may preferably comprise one or more adhesives selected from: single-layer adhesive, multi-layer adhesive, water-based adhesive, solvent-based adhesive, solvent-free adhesive, radiation-curing adhesive, thermally activated adhesive, thermally curable adhesive or combinations thereof.

[0051] In particular, it is provided that the at least one primer is applied by means of a printing process and / or by pouring and / or by a doctor blade. Furthermore, it is advantageous if the at least one primer is applied at least partially, preferably over the entire surface. The layer thickness of the individual adhesive layers within the primer is between 0.01 µm and 8.00 µm, preferably between 0.05 µm and 5.00 µm. In particular, it is provided that the adhesive layer or the adhesive layers comprise at least one binder selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, polyvinyl acetates, styrene block copolymers, phenol-formaldehyde resin adhesives, melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes, styrene, acrylates and / or combinations thereof.It is further preferred that the lacquer from which the adhesive layer is produced by an application process comprises at least one solvent selected from: water, aliphatic (gasoline) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, glycol ether acetates, and / or combinations thereof. This solvent or solvent mixture is largely removed again during the application process.

[0052] It is also possible for the at least one primer or adhesive to contain at least one additive selected from: hardeners, crosslinkers, photoinitiators, fillers, stabilizers, inhibitors, corrosion inhibitors, additives such as flow control additives, defoamers, deaerators, dispersing additives, wetting agents, lubricants, matting agents, rheology additives, pigments, anti-corrosion pigments, dyes, waxes, and / or combinations thereof. By appropriately selecting fillers or waxes, the tackiness of the at least one primer at room temperature can be reduced, for example.

[0053] In particular, a thermally activatable adhesive and / or an adhesive comprising thermoplastic and / or UV-based raw materials has a solids content in the range of 10% to 100%, preferably 15% to 35%. This allows for high-quality application on the coating machine. It is also preferably provided that the adhesive has a non-sticky surface after drying, particularly at room temperature. It is also advantageous if the raw materials of the adhesive are selected such that the processing temperature during production of the multilayer body is always above the glass transition temperature and below the melting point of the adhesive.

[0054] A multi-layer adhesive layer offers the particular advantage of achieving excellent adhesion even between highly demanding surfaces. Furthermore, a multi-layer structure enables primer systems that can meet a wide range of chemical and physical resistance requirements. Chemical resistance refers to the adhesive layer's resistance to the effects of chemicals. The composition of the adhesive layers is preferably selected to ensure sufficient resistance to predefined chemicals. Furthermore, it is advantageous for multi-layer adhesives to provide interlayer adhesion between the individual layers. This is achieved by appropriately selecting the adhesive components.

[0055] In particular, it is provided that the at least one metal layer comprises a material or a combination of materials selected from: aluminum, indium, silver, chromium, copper, tin, gold, zinc or an alloy of the aforementioned metals.

[0056] Advantageously, it is provided that the layer thickness of the at least one metal layer is in a range from 3 nm to 300 nm, preferably in a range from 5 nm to 100 nm.

[0057] It may also be possible for the metal layer to be applied to a replication layer in which optically variable structures are molded to generate optically variable effects. This allows, for example, color-shift effects to be realized.

[0058] Furthermore, the decorative layer can be provided with a full-surface metal mirror, particularly with high reflection. This can provide a molded part that can be used as an insulating material.

[0059] The color layer preferably consists of a combination of at least one binder and / or at least one filler, and optionally at least one additive. A color layer is preferably understood to be a special, functional layer that, in particular, creates a color impression that is perceivable by an observer.

[0060] Color is understood in particular to mean a coloring which, with regard to transparency and / or clarity or scattering power, preferably includes crystal-clear transparent coloring, scattering-transparent coloring, or even opaque coloring. The color preferably occurs as the intrinsic color of a material and / or is arranged in front of a layer as an additional colored layer in the viewing direction, wherein the underlying layer, in particular the metal layer, is modified in its colored appearance, especially for a viewer. The color preferably appears optically constant or invariable in its hue and / or color saturation and / or transparency under almost all, in particular all, viewing and / or illumination angles.It is also possible that the color itself is optically variable, with the hue and / or color saturation and / or transparency of the color changing in particular with changing viewing and / or illumination angles.

[0061] The color layer can be designed as a translucent color layer, in particular as a transparent or translucent color layer, wherein the transmittance of such a translucent, in particular transparent or translucent color layer is preferably between 25% and 99%, in particular over a partial range of the wavelength range visible to the human eye from 380 nm to 780 nm, preferably in the range from 430 nm to 690 nm.

[0062] The color layer can alternatively also be designed as an opaque, in particular as an opaque color layer, wherein the transmittance of such an opaque, in particular opaque, color layer is preferably between 0% and 25%, in particular over a partial range of the wavelength range visible to the human eye from 380 nm to 780 nm, preferably in the range from 430 nm to 690 nm.

[0063] The color layer preferably contains an additive and / or a filler that preferably absorbs light in the ultraviolet (UV) wavelength range, in particular in a wavelength range between 200 nm and 380 nm. In particular, the UV blockers exhibit no or only very low absorption in the wavelength range visible to the human eye from 380 nm to 780 nm, in order to avoid altering the color impression of the color layer.

[0064] Binders are preferably understood to mean polymer-based systems and their mixtures, such as polyester, polyacrylate, polymethacrylate, polyurethane, polystyrene, polybutyrate, nitrocellulose, polyvinyl chloride, ethylene vinyl acetate, their copolymers or similar polymers.

[0065] Additives are preferably understood to be organic or inorganic substances that achieve a predetermined effect on the processing properties, for example, when applying a color layer in the above process, particularly in step ii), or when using the security thread or multilayer body itself. For example, a UV blocker (UV = UV radiation = ultraviolet radiation = electromagnetic radiation from the ultraviolet part of the spectrum of electromagnetic radiation or from one or more sub-ranges of the ultraviolet part of the spectrum of electromagnetic radiation) can be an additive.

[0066] Fillers are preferably understood to mean all other materials added to a system, in particular a polymer-based system, such as silica, pigments, dyes, UV blockers, tracers, in particular taggants, and / or similar materials.

[0067] Dyes and / or pigments are preferably suitable as coloring substances for the at least one color layer. Pigments are preferably practically insoluble, in particular insoluble, in the medium into which they are integrated. Dyes preferably dissolve during use and, in particular, lose their crystal and / or particle structure. Possible classes of dyes are basic dyes, fat-soluble dyes, or metal complex dyes. Possible classes of pigments are organic and inorganic pigments. Pigments are preferably composed of a single-piece material or, alternatively, have complex structures, for example as layered structures with a plurality of layers made of different materials and / or, for example, as capsules made of different materials, in particular with a core and shell.

[0068] The color layer is in particular transparent or at least translucent, with the transmittance preferably being between 25% and 99%, in particular over a sub-range of the wavelength range visible to the human eye from 380 nm to 780 nm, preferably in the range from 430 nm to 690 nm. In particular, optically variable effects of the optically variable structures arranged below the at least one color layer from the viewer's perspective, which are incorporated in particular in the at least one replication layer, can be detected.

[0069] Furthermore, it is possible for the at least one color layer to be formed and / or consist of several different colors, wherein these preferably also include areas with color mixtures of the first and second colors, which are created by overlapping the color layers and / or by rasterizing the color layers. In particular, the color saturation in the color layers varies.

[0070] The color layer can be produced with at least one pigment or colorant of the color cyan, magenta, yellow or black (CMYK = Cyan Magenta Yello Key (Key = black as color depth)), in particular for producing a subtractive mixed color, or of the color red, green or blue (RGB), in particular for producing an additive mixed color.

[0071] As an alternative to mixed colours, pigments or dyes can also be used to produce a special, particularly premixed, special colour or colour from a special colour system (e.g. RAL, HKS, Pantone), for example orange or violet.

[0072] It can also be provided that the ink layer comprises a printed pattern, in particular a gradient.

[0073] In particular, it is provided that the at least one color layer has a layer thickness in the range of 0.1 µm to 30 µm, preferably in the range of 0.1 µm to 15 µm.

[0074] In particular, it is intended that the decorative sheet has a total layer thickness in the range of 100 µm to 500 µm, in particular in the range of 125 µm to 300 µm. The total layer thickness is understood to mean the thickness of the substrate including the thickness of all decorative layers or the entire decorative layer.

[0075] Preferably, the substrate comprises polypropylene (PP) as its material. It may also be possible for the substrate to comprise a material or combination of materials selected from: polypropylene (PP), polyethylene (PE), polyolefins, polyethylene terephthalate (PET), biodegradable biopolymers, in particular polylactide (PLA). It is particularly advantageous if the material of the substrate matches or is at least similar to the material of the thermoplastic fiber. Preferably, both the substrate and the thermoplastic fibers are made of polypropylene.

[0076] In particular, it is possible for the substrate to be available in different colors. It may also be transparent or translucent. Furthermore, the color of the substrate may match or at least be similar to the color of the thermoplastic fibers. Alternatively, it is also possible for the color of the substrate to be different from the color of the thermoplastic fibers. It is also possible for the thermoplastic fibers to be transparent or translucent.

[0077] Furthermore, it is preferably provided that the substrate has a layer thickness in the range of 100 µm to 500 µm, in particular from 125 µm to 300 µm. Tests have shown that with substrates that are too thick, the feel of the natural fibers is no longer perceptible after the decoration process, and the characteristic visual appearance is no longer visible. The above layer thicknesses can thus preserve the tactile feel of the natural fibers and their characteristic visual appearance.

[0078] In particular, it is possible that after step b) and before step c), the fiber mat is placed in a press, in particular a calibration press, and the fiber mat is calibrated without the decorative sheet. This can reduce the temperature stress on the decorative sheet.

[0079] In particular, it is possible that after calibrating the fiber mat without the decorative sheet, the fiber mat is then placed together with the decorative sheet in a press, in particular a calibration press, and the fiber mat is recalibrated together with the decorative sheet.

[0080] Furthermore, it is also possible to add or insert reinforcing materials, especially meshes, in step c). These reinforcing materials provide the necessary stability to the fiber mat or the subsequent molded part. The appropriate reinforcing materials are selected depending on the intended use.

[0081] It may also be provided that a heating foil is additionally inserted in step c). This heating foil can be used to heat the molded part later, for example, for functional heating of the molded part during its normal use.

[0082] It can also be provided that, in step c), a sensor with an edge-side tail is additionally inserted. The sensor can then be connected via the edge-side tail to a corresponding processing unit, which can process the sensor data.

[0083] Step d), i.e. the pressing of the fiber mat and the decorative sheet, compacts the fiber mat and significantly reduces the strength or thickness of the fiber mat.

[0084] It is preferably possible for the press, in particular the calibration press, to have two planar, heatable plates or surface stamps in step d), by means of which the thermal heating of the fiber mat and the decorative web takes place. It can also be provided that only one of the surface stamps is heatable, for example the lower surface stamp or the upper surface stamp. It is preferably provided that the fiber mat with the decorative web is pressed for a predetermined period of time at a predetermined temperature and under a predetermined pressing force. These can also be variable parameters. For example, the temperature can be increased or reduced during pressing. It is also conceivable for the pressure or pressing force to increase or decrease gradually. Furthermore, it is possible for the pressure or pressing force to increase or decrease abruptly.Preferably, the parameters are adjusted and selected accordingly depending on the fiber mat and decorative web. It is also possible for the press's movable upper surface ram to briefly lift from the fiber mat, preferably for between 1 and 5 seconds, and then press the fiber mat again. This brief lifting can serve, in particular, to vent the calibration press. However, it is conceivable that, within this short period of time, an additional decorative web and / or an additional functional web or layer could be placed on top of the fiber mat in the calibration press and positioned preferentially.

[0085] It is preferably provided that the pressing in step d) takes place at a temperature in a range from 150°C to 250°C, in particular in a range from 170°C to 230°C, particularly preferably in a range from 180°C to 210°C.

[0086] It may also be possible for the pressing in step d) to be carried out with a pressing force in a range from 180 kN to 220 kN, in particular in a range from 185 kN to 210 kN, preferably wherein the pressing force is built up continuously or stepwise over time by closing the press or the pressing force is reached suddenly.

[0087] It is particularly advantageous if the pressing in step d) takes place for a duration ranging from 30 seconds to 180 seconds. The duration preferably depends on the thickness of the fiber mat and the thickness of the decorative sheet.

[0088] Preferably, it is possible for the fiber mat to be deformed three-dimensionally or 2.5-dimensionally during the pressing process in step d). Preferably, after the pressing process in step d), a deformed, in particular three-dimensionally deformed or 2.5D-deformed, decorated molded part is provided. It is also preferably possible for the decorated molded part to be deformed three-dimensionally or 2.5-dimensionally.

[0089] It has advantageously been found that in step d) the decorative web forms a material bond with the fiber mat, in particular with the thermoplastic fibers of the fiber mat, in particular due to thermal heating.

[0090] It is preferably possible that in step d) the material of the substrate, in particular the polypropylene of the substrate, is softened and / or plasticized by the thermal heating and geometrically sinks into the fiber mat, whereby a partial decoration of the natural fibers arranged in the upper boundary region of the fiber mat takes place, so that a mottled appearance is created.

[0091] In particular, it is possible that the upper limit range is a maximum of 50%, preferably a maximum of 33%, of the total thickness of the fiber mat, in particular of the decorated molded part.

[0092] Furthermore, it may also be possible for the lower region to be a maximum of 67%, preferably a maximum of 50%, of the total thickness of the fiber mat, in particular of the decorated molded part.

[0093] The above-mentioned mottled appearance is preferably formed by the decorated natural fibers in the upper border area and by the composite of the substrate of the decorative sheet and thermoplastic fibers. The decorated natural fibers are generally lighter in appearance than the background, with the background being formed by the composite. However, the reverse is also possible, i.e., the decorated natural fibers are darker in appearance than the background, with the background being formed by the composite. Furthermore, it is also conceivable that the background formed by the composite is transparent or translucent.

[0094] It is preferably provided that in step d) the color of the substrate of the decorative web and / or the color of the thermoplastic fibers essentially represents the visible background color of the mottled appearance.

[0095] Preferably, in step d), the thermoplastic fibers are softened and / or plasticized to form a melt, so that the density of the thermoplastic fibers increases due to this melt and the melt sinks into the fiber mat, starting from the upper boundary region of the fiber mat toward the lower region of the fiber mat, causing the natural fibers, in particular those that do not melt, to partially protrude from the melt. This ensures that the haptic properties of the natural fibers can be felt or grasped in the subsequent molded part and that their characteristic visual appearance is preserved.

[0096] In particular, it is provided that in step d), as the substrate of the decorative sheet sinks into the fiber mat, the decorative layer sinks and / or infiltrates the upper boundary area of the fiber mat. As a result, the natural fibers in the upper boundary area are at least partially covered by the decorative layer and thus decorated. This also promotes the mottled appearance described above.

[0097] The forming process in step e) is also commonly referred to as thermoforming. In particular, the fiber mat is deformable after step d) due to thermal heating, is deformed in step e), and then solidified into a molded part by cooling.

[0098] Preferably, immediately after pressing in step d), the still soft and deformable fiber mat is inserted into the molding tool. This is advantageously done manually. Alternatively, it can also be done using a robot, in particular a robot arm.

[0099] It is preferably provided that in step e) the mold has two mold halves, in particular wherein the two mold halves are not heated. By “not heated” is meant here that the mold halves have a temperature below the softening temperature of the thermoplastic matrix. The two mold halves are preferably three-dimensional mold halves with which the decorated fiber mat is deformed into a molded part. Because the mold halves are not heated, the plasticized or molten material of the substrate and / or the thermoplastic fibers can cool and solidify. It may also be possible for the two mold halves to be actively and / or passively tempered. If the tempering includes cooling, the cooling of the plastic mass can take place even faster and the throughput is increased.

[0100] It is preferably provided that in step e) the forming takes place at a pressing force in a range of 550 kN to 650 kN, in particular in a range of 560 kN to 640 kN.

[0101] Preferably, in step e), the molding takes place for a time in the range of 30 seconds to 60 seconds. The time is preferably selected such that the molten material of the substrate and the thermoplastic fibers cools and solidifies into a solid, particularly cohesive, composite. This ensures that the geometry of the molded part no longer changes upon or after removal of the molded part from the mold.

[0102] Preferably, in step e), the molding takes place at a maximum temperature of 80°C. In this case, the two mold halves can be temperature-controlled or have corresponding heating elements.

[0103] In particular, it is possible that in step e), the melted substrate of the decorative sheet and the melted thermoplastic fibers of the fiber mat solidify, thus causing shrinkage of the thermoplastic materials. This shrinkage causes more natural fibers to emerge from the surface of the molded part, thus improving the feel of the decorated natural fiber mat.

[0104] Furthermore, it can also be provided that in step e) an additional trimming takes place in the mold or that after step e) a separate trimming of the molded part takes place by means of a knife and / or laser, so that the molded part is adapted to the final shape.

[0105] Furthermore, it may be provided that after step e) the following step is carried out: f) Back-injecting the molded part with a plastic compound, preferably in the mold or in an injection molding machine, in order to attach assembly elements and / or reinforcement elements.

[0106] The addition of mounting elements or reinforcement elements makes the decorated molded part versatile and can thus be individually adapted to the intended application. For example, mounting elements for attaching the molded part to a vehicle body or light guides for coupling and / or decoupling light can be provided. Examples of plastic materials that can be used include polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyamide (PA), acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate / acrylonitrile-butadiene-styrene copolymer (PC / ABS), polybutylene terephthalate (PBT), or polymethyl methacrylate (PMMA). Accompanying materials such as fiberglass, talc, or gases for foaming, etc., can also be incorporated.

[0107] In particular, it is provided that the decorated fiber mat after step d) and / or the decorated molded part after step e) has a thickness in the range from 1 mm to 4 mm, in particular from 1.5 mm to 3.5 mm.

[0108] The decorated molded part is preferably a three-dimensional geometry with various curves, depressions, recesses, etc. The effect resulting from the decoration preferably varies in intensity depending on the radius of curvature and / or viewing angle. For example, if the decorative layer is metallic silver and the substrate of the decorative strip is opaque black, the decoration process results in a bright metallic shimmer "in the black" of the substrate. This bright shimmer varies in intensity depending on the radius of curvature and / or viewing angle, and can also be described as a visually variable appearance.

[0109] In particular, it is provided that the decorated molded part has a mottled appearance due to the at least partial decoration of the natural fibers in the upper boundary area, in particular wherein the at least partially decorated natural fibers stand out from the background, preferably wherein the background is essentially formed by the thermoplastic composite of the fused thermoplastic fibers and the substrate of the decorative web.

[0110] Furthermore, it can be provided that the decorated molded part is decorated in a first region and not decorated in a second region. Preferably, the second region has the background color of the decorated molded part, which is also visible in the background of the first region.

[0111] Since, in the present method for producing a decorated molded part, the decorative sheet is preferably inserted into a press such that the decorative layer faces the fiber mat, the decorative layer itself does not need to meet any special requirements regarding durability, etc., since the surface of the decorated molded part is predominantly covered by the substrate of the decorative sheet or is formed by the substrate and the underlying fiber mat. This is preferably due to the fact that the decoration only accounts for a small portion of the surface of the decorated molded part.

[0112] Nevertheless, there are certain specifications or requirements, primarily known from the automotive industry, that such a fiber mat must ideally meet. These requirements have been confirmed by a series of tests, which are presented below.

[0113] For all subsequent tests, a decorated molded part or a sample of a decorated molded part was used.

[0114] Among other things, the cream resistance of the decorated molded part was tested according to test method VW PV 3964. For this purpose, appropriate samples are first cut to size, which are then conditioned for seven days at room temperature, in particular in a temperature range of 18°C to 28°C, or for 48 hours at 60°C in a circulating air oven. A 20-thread gauze bandage according to DIN 61631 is then placed on the samples. The test medium, in this case Test Cream Type A from Thierry GmbH or Test Cream Type B from Thierry GmbH, is applied to the gauze bandage and pressed through the gauze bandage onto the sample surface and spread. It is preferable that the spaces between the meshes of the gauze bandage are filled with the test medium.

[0115] The size of the gauze bandage and the amount of test medium should preferably be selected depending on the sample size. The prepared sample is then stored or conditioned in a convection oven at a temperature of 80°C for a period of 24 hours. The sample is then removed from the convection oven, the gauze bandage removed, and any remaining test medium is wiped off with a clean cloth. Before the sample is evaluated and subjected to further tests, it is conditioned again for a period of 4 hours at room temperature, preferably within a temperature range of 18°C to 28°C.

[0116] Unless otherwise requested, a visual inspection of color and appearance is performed first. It is preferred that there be no change in appearance, i.e., no crow's feet or swelling, and no change in haptic properties, such as softening or increased stickiness, compared to the original molded part or the original sample (without test medium). An increase in gloss, for example, is permissible.

[0117] Furthermore, the cream test preferably involves a cross-cut test according to DIN EN ISO 2409, followed by a sudden adhesive tape tear. A cross-cut characteristic value of ≤ 1 is required. The cross-cut test is described in detail below.

[0118] Furthermore, the cream test preferably also involves a cross-cut followed by tape removal. This involves cutting a cross (St. Andrew's cross) into the surface of the sample using a knife with a sharp, thin blade, e.g., a safety knife with a trapezoidal handle (also called a craft knife), and then applying tape. After removing the tape, no paint particles should remain on the tape.

[0119] Furthermore, the cream test is preferably also used to test scratch resistance. For samples or components with complex geometries, the scratch resistance of the sample surface is tested using an Erichsen hardness test bar at a load of up to 10 N and a Bosch test needle (0.75 mm tip). A detailed description of the scratch resistance test follows below. Cracking of the coating down to the base material is not permitted. An indentation in the substrate due to the load is permissible.

[0120] For samples with a flat surface, the cream test is preferably carried out using a grid test according to VW PV 3952.

[0121] It is preferably provided that the decorated molded part has a fastness rating of the gray scale in the range of 4 to 5 and a cross-cut characteristic value of ≤ GT 1 according to DIN EN ISO 2409 and no change in haptics and color in a cream resistance test according to VW PV 3964 with a test cream type A and / or type B.

[0122] Furthermore, the decorated molded part was subjected to a hydrolysis test according to test method BMW AA-0203. For this purpose, appropriate samples are first cut and then conditioned for seven days at room temperature or for 48 hours at 50°C in a convection oven. Conditioning for seven days at room temperature is preferable.

[0123] Room temperature for storage and / or conditioning is understood to mean, in particular, the temperature range from 18°C to 28°C.

[0124] The cycle described below is then carried out once. The sample is conditioned in a climate chamber for a test period of 72 hours at a temperature of 90°C ± 2°C and a relative humidity of 95% ± 2%. The sample is then stored at room temperature for a period of 24 hours. After storage, adhesion tests are carried out using cross-cut adhesion tests in accordance with BMW AA-0180 or BMW GS 97034-9. The evaluation is carried out according to BMW AA-0180 or BMW GS 97034-9. Surface changes, such as blistering, paint peeling, or paint softening, are not permitted. Furthermore, any change in the shape of the substrate or sample should preferably be included in the test report.

[0125] It is preferably provided that the decorated molded part does not exhibit any surface changes in a hydrolysis test according to BMW AA-0203 and has a gray scale fastness rating in the range of 4 to 5 and a cross-cut characteristic value of ≤ GT 1 according to BMW AA-0180 and a grade of 1B in a fingernail test according to BMW GS 97034-2.

[0126] As mentioned above, cross-cut tests according to DIN EN ISO 2409, BMW AA-0180, and BMW GS 97034-9 are also performed for the evaluation of the cream test and the hydrolysis test. However, the cross-cut test can also be performed independently to provide information about the durability of the sample or the decorated molded part.

[0127] To prepare the sample, it is first stored at room temperature for seven days.

[0128] In cross-cut testing, a distinction is preferably made between hard and soft substrates. Hard substrates include steel, aluminum, magnesium, thermosets, and similar materials. Soft substrates include, for example, thermoplastics, PP, EPDM, polyamides, ABS, PC, and similar materials.

[0129] In contrast to the testing according to DIN EN ISO 2409, all paint finishes tested according to BMW AA-0180 are tested as hard substrates. This means that the test is always performed with adhesive tape removal, regardless of the substrate.

[0130] Before testing, the surface of the sample or the area to be tested is thoroughly cleaned with a clean cleaning cloth soaked in isopropanol (2-propanol). It is important that any contaminants are removed completely. Furthermore, it is preferable to avoid scratches caused by cleaning by selecting suitable cleaning cloths. Testing may only be performed when the surface of the sample is visually dry and free of any propanol residue.

[0131] Next, a cross-cut is made on the surface of the sample using the appropriate cutting tool, preferably at an angle of 90°. When using a utility knife according to DIN EN ISO 2409, an angle of 30° ± 10° to the surface of the sample must be maintained. If possible, a template should be used to ensure that the cut is made at a 90° angle to the surface in the cutting direction.

[0132] Only those cross-cuts that are clearly even and continuous down to the substrate and consist of at least six individual cuts in each direction of the grid may be assessed. A magnifying glass may be used to check the continuity of the cuts down to the substrate.

[0133] Furthermore, especially with soft substrates, care should be taken to ensure that the damage to the substrate is as minimal as possible, i.e., that the cut is made close to the surface. If the damage to the substrate is too deep, the adhesion of the coating will be negatively affected by various forces. Depending on the total layer thickness and the substrate, the cutting distances listed in the following table must be observed, deviating from DIN EN ISO 2409: Total layer thickness Cutting / cutting distance Hard surfaces Soft surfaces ≤60 µm 1 mm 2 mm 61-200 µm 2 mm 2 mm 201-250 µm 3 mm 3 mm > 250 µm No longer evaluated, test procedure unsuitable

[0134] The following procedure for removing the adhesive tape applies to all coatings and substrates. To do this, first remove any cutting residue from the surface using a soft brush by gently brushing back and forth. The adhesive tape is then pressed firmly and evenly onto the cut surface using the edge of the wooden back of the brush, parallel to the direction of the cross-cuts. This means that the surface of the applied adhesive tape must appear lighter in color after pressing. Avoid pressing too hard or too intensively. If the adhesive tape is pressed on too firmly, a cream-colored fabric will appear. After one minute at the most, the adhesive tape is pulled off quickly and jerkily in one movement at an angle of, if possible, 60° to the sample surface. The adhesive tape is to be used only once.Furthermore, care must be taken to ensure that the adhesive surface, which is adhered to the cross-cut, is not contaminated by fingerprints or other adhesion-reducing substances. Furthermore, the sample must be secured to a solid surface during removal, e.g., by hand, using adhesive tape, or a magnetic block.

[0135] Generally, the adhesive tape is peeled off once in the direction of the cross-cut, approximately at a 90° angle to each other, and the surface is assessed or evaluated accordingly. If the initial assessment results in a cross-cut characteristic value of GT ≥ 1, a further adhesive tape peel cycle is performed, this time in the opposite direction to the cutting direction. In total, the tape is peeled off once in both clockwise and counterclockwise directions. The final assessment or evaluation then follows.

[0136] The criteria for classifying the cross-cut values are based on DIN EN ISO 2409:2013-06 or ASTM D3359-09. These criteria are shown in the table according to Fig. 8 summarized.

[0137] Preferably, the decorated molded part has a cross-cut characteristic (GT) of at least 1 after a visual assessment using the test method according to DIN EN ISO 2409:2013-06 and / or a value of 4B according to ASTM D3359-09. This applies in particular to all tests in which the cross-cut test is used as an evaluation criterion to assess the durability of the decorated molded part.

[0138] If delamination occurs only outside the cross-cut area to be assessed, e.g. at the extension of the cuts, it is assessed using a different assessment scheme, which is briefly explained below, in deviation from DIN EN ISO 2409.

[0139] If the de-adhesive area outside the grid cut corresponds to up to 15% of the area (corresponds to a maximum of 3 squares) of the total of 25 squares within the grid cut, the grid cut is rated GT 1.

[0140] If the area removed from the grid pattern is between 16% and 35% (equivalent to 4 to 8 squares), it is rated GT 2. If the area removed from the grid pattern is between 36% and 65% (equivalent to 9 to 16 squares), it is rated GT 3. If the area removed from the grid pattern is more than 66%, it is rated GT 4 or GT 5.

[0141] If delamination occurs both inside and outside the cross-cut area being assessed, the lower value achieved is reported as the result. If a utility knife is used to perform the cross-cut, this must be indicated or supplemented in the corresponding test report as a word or with a "c," e.g., "GT 1 c." Cross-cut values without any supplement / marking are generated using a multi-blade tool according to this logic. The type of cutting tool used (multi-blade tool or utility knife with snap-off blades) influences the test result. The results of the different cutting tools cannot be directly compared.

[0142] As mentioned above, for example, a scratch resistance test according to BMW GS 97034-9 is also performed for the evaluation of the hydrolysis test according to BMW AA-0203. However, the scratch resistance test can also be performed independently to provide information about the durability of the sample or the decorated molded part.

[0143] When testing scratch resistance, one or more samples with a length of at least 90 mm and a width of at least 50 mm are first prepared and then conditioned for 24 hours under standard conditions according to DIN EN ISO 291-23 / 50 (Class 2). Preferably, the samples have a flat surface. Before testing, the samples are cleaned without pressure using a microfiber cloth moistened with a laboratory detergent, such as Mucasol 3% in demineralized water (= fully demineralized water or deionized water).

[0144] The preferred test specimen is an Erichsen point with a diameter of 0.75 mm. This Erichsen point is preferably made of hardened steel. The point should be examined under 30x magnification before each test. Priority should be given to checking whether the point is smooth, hemispherical, and free of scratches and contaminants. If necessary, the point may need to be replaced or cleaned.

[0145] During the test, the specified test specimen is moved relative to the surface of the sample at a constant test force and constant speed. The test speed is preferably 40 ± 5 mm / s. The test force is increased in stages (1 N, 2 N, 3 N, 5 N, 8 N and 10 N). The surface to be tested is loaded once for each test force. To better evaluate the individual gradations, the line spacing must be shifted by 5 mm after each scratch test when the load changes. The test path is preferably between 50 mm and 100 mm. Any test setup that allows testing within the listed parameters is ideally suitable for carrying out the scratch resistance test.

[0146] After testing, the samples are cleaned without pressure using a microfiber cloth moistened with deionized water. Assessment is performed after a 24-hour recovery period. Evaluation is performed according to the BMW AA-0635 evaluation scheme.

[0147] Furthermore, a hand abrasion test is preferably conducted. This test, for example, examines the movement of a finger or hand.

[0148] Manual operation is simulated. Furthermore, the influence of sweat, hand cream, or other media can be taken into account by using test media. It is also possible to test continuous stress. The test method is particularly suitable for components with curved and / or structured surfaces, as well as for flat specimens, thanks to variable clamping and test travel distances.

[0149] In the hand abrasion test, one or more samples are first prepared and conditioned for a period of 24 hours under standard conditions according to DIN EN ISO 291-23 / 50 (Class 2). Before testing, the samples are cleaned without pressure using a microfiber cloth moistened with a laboratory detergent, such as Mucasol 3% in demineralized or deionized water. For sensitive surfaces, a microfiber cloth with a fine weave is preferable. The test is also carried out according to the original setup under standard conditions according to DIN EN ISO 291-23 / 50 (Class 2).

[0150] In hand abrasion tests, a test die performs a specified number of strokes with a defined test force. The geometry, material, and hardness of the test die are designed to create a flexing motion on the sample surface. The test die with the item number ABR-2061-01 Z from Innowep preferably has an outer diameter of 20 mm and a hardness of 47 ± 5 Shore A. A test fabric is placed between the sample and the test die. This fabric is either automatically advanced by a device or is attached directly to the test die. The test fabric is used to create a defined frictional load on the sample surface. Depending on the test being conducted, a test fluid can also be applied to simulate chemical stress. When using test media, the test fabric is attached to the test die and replaced after 250 double strokes.

[0151] The test stroke of the flexion movement is 40 mm, and 0.58 test cycles are performed per second. The test speed is preferably 60 ± 5 mm / s. The test force is 10 N. Depending on the component, 60 or 4000 strokes are performed. The specifications of the specimens to be tested and the test parameters to be used can be found in the standards BMW GS 97034-1 and BMW GS 97060-2.

[0152] One hour after the abrasion test, the samples should be cleaned without pressure using a microfiber cloth moistened with deionized water. The samples are evaluated 24 hours after the abrasion test to take into account their recovery behavior.

[0153] The tested samples are assessed visually under standard D65 light. Starting with the frontal view, the viewing angle is varied until maximum contrast is visible. The contrast or abrasion trace compared to the unexposed surface is assessed using a gray scale according to DIN EN 20105-A02 (levels 1 to 5). The assessment must be performed by at least two people experienced in assessing contrast changes using this method. For materials that cannot be meaningfully assessed using a gray scale, the assessment is performed according to the evaluation scheme listed in the following table: Key figure BI Condition Examples 9-10 OK condition No change 8 OK condition - minimal gloss / matting - minimal abrasion of the grain or the paint 7 The customer's perception of quality is not significantly affected. Quality deviations from the target are primarily detected only by specialists. This indicates process improvement / trend detection. - slight gloss / matting - slight abrasion of the grain or the varnish - structure still unchanged - slight reversible deformation of the surface 6 Visual or tactile characteristics that are recognizable by the customer. Raises awareness of defects. - significant gloss / matting - significant abrasion of the grain or the varnish - slightly altered structure - slightly visible traces of the abrasion fabric - slight permanent deformation 5 Unacceptable visual or tactile characteristics that are clearly noticeable to the customer and cause dissatisfaction. This defect is usually reported during the next workshop visit. - strong gloss / matting - structure barely recognizable - clearly visible traces of the abrasion fabric - strong permanent deformation - permanent discoloration due to soiling fabric 4 A visual defect with functional relevance that significantly impairs long-term quality (e.g., risk of corrosion) or can lead to injury. This defect may result in an unscheduled visit to the workshop. - strong gloss formation / matting - complete abrasion of the grain or the paintwork - no longer recognizable structure - destruction of the material / surface

[0154] For fiber mats, a BI index of 8 or better is preferred.

[0155] In particular, it is intended that the decorated molded part has a test result of at least BI 8 in a dry and / or non-grip-loaded hand abrasion test and / or in a hand abrasion test with acidic artificial sweat and / or in a hand abrasion test with alkaline artificial sweat and / or in a hand abrasion test with sunscreen and / or in a hand abrasion test with hand cream, each in accordance with the test method BMW GS 97034-1.

[0156] Furthermore, it is also specifically intended that the decorated molded part has a test result of at least BI 8 in a dry grip-loaded hand abrasion test according to test method GS 97034-1.

[0157] Furthermore, the decorated molded part was subjected to further tests, such as a fingernail test or a test to assess the color abrasion behavior.

[0158] Preferably, the decorated molded part has a rating of ≤ 2B in a fingernail test according to the test method according to BMW GS 97034-2 with a force of 15 N.

[0159] In particular, it may be possible for the decorated molded part to achieve a test result of ≥ GM 4 in a test to assess the paint abrasion behavior according to test method BMW GS 97034-4 and test procedure A using glass cleaner and / or interior cleaner and / or cockpit spray and / or plastic care emulsion as test fluid.

[0160] Below, all tests carried out, as well as their test methods, requirements and test results, are presented in a table. test Test method Requirements Result Hydrolysis test BMW AA-0203 Evaluation according to BMW AA-0180, BMW GS 97034-9 and BMW AA-0635 GT ≤ 1 No change If F = 10 N: Grades 2C and 3C not permitted GT 0 No change in gray scale 4-5 10 N: 1 B Hand abrasion (not grip-loaded) Dry BMW GS 97034-1 Ranges according to BMW GS 97060-2 60 strokes BI ≥ 8 BI 10 Hand abrasion (grip load) Dry BMW GS 97034-1 Ranges according to BMW GS 97060-2 4000 strokes BI ≥ 8 BI8 Hand abrasion (grip-loaded) artificial sweat acidic (GS 94011-9.9-8) BMW GS 97034-1 Ranges according to BMW GS 97060-2 60 strokes BI ≥ 8 BI 10 Hand abrasion (grip-loaded) artificial perspiration alkaline (GS 94011-9.9-7) BMW GS 97034-1 Ranges according to BMW GS 97060-2 60 strokes BI ≥ 8 BI 10 Hand abrasion (grip-loaded) Sunscreen (Thierry) BMW GS 97034-1 Ranges according to BMW GS 97060-2 60 strokes BI ≥ 8 BI 10 Hand abrasion (grip-loaded) Hand cream (Thierry) BMW GS 97034-1 Ranges according to BMW GS 97060-2 60 strokes BI ≥ 8 BI 10 Fingernail test BMW GS 97034-2 F = 15 N Grade ≤ 2B Grade: 1B Color abrasion behavior of glass cleaners BMW GS 97034-4 Test Procedure A GM ≥ 4 GM 5 Paint abrasion behavior of interior cleaners BMW GS 97034-4 Test Procedure A GM ≥ 4 GM 5 Paint abrasion behavior cockpit spray BMW GS 97034-4 Test Procedure A GM ≥ 4 GM 5 Color abrasion behavior of plastic care emulsion BMW GS 97034-4 Test Procedure A GM ≥ 4 GM 5 Cream resistance test cream according to VW PV 3964 Type A (sunscreen) VW PV 3964 No change in color and feel Fastness rating of the gray scale > 4 (DIN EN 20105-A02) Gt ≤ 1 No change in color and feel Authenticity rating of the gray scale 4-5 (DIN EN 20105-A02) Gt 0 Cream resistance test cream according to VW PV 3964 Type B (hand cream) VW PV 3964 No change in color and feel Fastness rating of the gray scale ≥ 4 (DIN EN 20105-A02) GT ≤ 1 (2.1) No change in color and feel Authenticity rating of the gray scale 4-5 (DIN EN 20105-A02) GT 0

[0161] The decorated molded part or the process for producing a decorated molded part provides a decorated molded part with the feel of a fiber mat, which can be used for a wide variety of applications. For example, such molded parts are suitable for parts of a vehicle interior. The molded part is particularly well-suited as an interior door panel, a cockpit element, a dashboard, and many more. Due to their low density and high strength, fiber composites are particularly suitable for decorative parts and / or trim parts for vehicle interiors. A key advantage of the molded part is that it can replace trim parts that are currently made from solid plastic parts. This reduces the use of plastics.

[0162] The invention is explained below using several exemplary embodiments with the aid of the accompanying drawings. The exemplary embodiments shown are therefore not to be understood as limiting. Fig. 1 shows schematically the process steps of a process for producing a decorated molded part; Fig. 2a - 2d show schematically selected process steps of a process for producing a decorated molded part in detail; Fig. 3 shows a microscope image of the visible side of the decorated molded part Fig. 4 shows a microscope image of the visible side of the decorated molded part Fig. 5 shows a microscope image of the visible side of the decorated molded part Fig. 6 shows a microscope image of the visible side of the decorated molded part, with a decorated area arranged next to an undecorated area Fig. Figure 7 shows a micrograph of the visible side of the decorated molded part, with a decorated area arranged next to an undecorated area Fig. 8 shows a table for classification of cross-cut values according to DIN EN ISO 2409:2013-06 or ASTM D3359-09.

[0163] The figures illustrate various examples of embodiments of the invention. Identical or equivalent components have been provided with the same reference symbols. Where the embodiments illustrated in the figures have common features, these common features have been omitted from being described multiple times to avoid repetition. The respective differences between the embodiments are described in relation to the figures. It goes without saying that a person skilled in the art can modify individual embodiments or combine individual features of these embodiments within the scope of the claims.

[0164] Furthermore, all figures are not drawn to scale. The proportions shown in the figures were chosen so that the individual layers of the molded part 10 can be adequately represented.

[0165] The Fig. 1 schematically shows a method for producing a decorated molded part 10, wherein the method comprises the following steps, in particular in the following order: a) providing a decorative sheet 1, 12, wherein the decorative sheet 12 comprises a substrate 13 and at least one decorative layer 14 applied to the substrate 13; b) providing a fiber mat 2, 11, wherein the fiber mat 11 comprises natural fibers and thermoplastic fibers; c) inserting the fiber mat 11 and the decorative web 12 into a press 3, in particular into a calibration press, wherein the decorative web 12 is arranged on the fiber mat 11 such that the at least one decorative layer 14 of the decorative web 12 faces the fiber mat 11; d) pressing the fiber mat 11 and the decorative web 12 under thermal heating 4, so that the substrate 13 of the decorative web 12 fuses with the thermoplastic fibers of the fiber mat 11 and the decorative layer 14 of the decorative web 12 at least partially decorates the natural fibers arranged in an upper boundary region 40 of the fiber mat 11 in order to provide a decorated fiber mat 11; e) forming the decorated fiber mat 11 in a mold 5 to obtain a decorated molded part 10.

[0166] Because the decorative sheet 12 is inserted on the back, i.e. with the decorative layer 14 facing the fiber mat 11, in step c), the natural fibers can be decorated with the decorative layer 14 of the decorative sheet 12 in an upper boundary region 40 during pressing in step d) by thermal heating. This is preferably due to the fact that in step d) the material of the substrate 13 and the thermoplastic fibers are plasticized or softened by the thermal heating. As a result, the plasticized material sinks into the fiber mat 11. In the sinking direction of the material of the substrate 13, however, lies the decorative layer 14, which also disintegrates into small surface areas due to the melting of the very soft material of the substrate 13 and / or the thermoplastic fibers, in particular the polypropylene.Due to the sinking of the plasticized material of the substrate 13 and / or the thermoplastic fibers, the natural fibers now appear in the upper boundary region 40 of the fiber mat 11, to which the surface areas of the decorative layer 14 adhere and thus the natural fibers are at least partially decorated.

[0167] Furthermore, it can be provided that, in order to provide the decorative sheet 12 in step a), the following steps are carried out, in particular in the specified order: - Providing the substrate 13; - Applying the decorative layer 14 by printing and / or by transferring a transfer layer of a transfer film, in particular by hot stamping.

[0168] When applying the decorative layer 14 by printing, this is preferably done using a printing process, individually or in combination, selected from: screen printing, gravure printing, digital printing, inkjet printing, laser printing. When applying a transfer layer of a transfer film, the transfer layer of the transfer film preferably functions as the decorative layer 14. The transfer film, in particular hot stamping foil, preferably comprises a carrier and a transfer layer that can be removed from the carrier by means of a release layer. This transfer layer can have at least one layer or combinations of several layers selected from: ink layer, metal layer, replication layer, protective lacquer layer, primer, adhesive layer, primer, adhesion promoter layer, barrier layer, conductive layer, lacquer layer.

[0169] The application of the decorative layer 14 can, for example, comprise the application of a transfer layer of a transfer film and a subsequent overprinting of the applied transfer layer on the substrate 13. For example, the transfer layer can have a metal layer, and the overprinting of the transfer layer can be carried out with one or more translucent color layers, so that in particular the optical effect of a colored metal layer is created.

[0170] Preferably, it may be possible for the transfer layer to be transferred at least partially or over the entire surface onto the substrate 13 of the decorative web 12 by means of a hot stamping tool, in particular by means of a hot stamping stamp and / or by means of a hot stamping wheel.

[0171] It is also preferably possible for several prints and / or transfer layers of transfer films to form the decorative layer 14 of the decorative web 12.

[0172] In particular, it is provided that in step a), the decorative layer 14 is applied to the front and / or back of the substrate 13. In particular, if the decorative layer 14 is applied to both the front and back of the substrate 13, it is preferably provided that in step a), a protective lacquer layer is applied to the front of the substrate 13. This protective lacquer layer then has the task of protecting the decorative layer 14 applied to the front of the substrate 13. This is because, unlike the decorative layer applied to the back, this decorative layer 14 applied to the front is not protected by the substrate 13 of the decorative sheet 12.

[0173] It may also be possible for the fiber mat 11 to be placed in a press, in particular a calibration press, after step b) and before step c), and for the fiber mat 11 to be calibrated without the decorative sheet 12. This allows the fiber mat 11 to be pre-pressed, and the thermoplastic fibers to begin melting before the decorative sheet 12 is placed onto the fiber mat 11 in the subsequent step c) and subsequently pressed with it in step d). This allows the thermal stress on the decorative sheet to be reduced.

[0174] In particular, it is possible that after calibrating the fiber mat 11 without the decorative web 12, the fiber mat 11 is then placed together with the decorative web 12 into a press, in particular a calibration press, and the fiber mat 11 is calibrated again together with the decorative web 12.

[0175] In the Fig.2a to 2d schematically show in detail the process steps c) to e), which have already been described above, of a process for producing a decorated molded part 10.

[0176] Fig. 2a shows step c), i.e. the insertion of the fiber mat 11 and the decorative web 12 into a press, in particular a calibration press, wherein the decorative web 12 is arranged on the fiber mat 11 such that the at least one decorative layer 14 of the decorative web 12 faces the fiber mat 11. The Fig. The versions shown in Figures 2a to 2d are simplified versions. For example, in the Fig. 2a shows the decorative sheet 12 in a simple form, such that the decorative sheet 12 has a substrate 13 and a decorative layer 14. However, it may also be possible for the decorative sheet 12 to have multiple decorative layers 14.

[0177] The substrate 13 preferably comprises polypropylene (PP) as its material. Polypropylene is particularly suitable because it is inexpensive and easily recyclable. Thus, for example, recycled polypropylene can be used to produce the decorative sheet 12. Advantageously, the material of the substrate 13 of the decorative sheet 12 matches the material of the thermoplastic fibers of the fiber mat 11. Therefore, it is preferably provided that the thermoplastic fibers and the substrate 13 of the decorative sheet 12 are made of polypropylene.

[0178] It may be possible for the decorative sheet 12 to have a total layer thickness in the range of 100 µm to 500 µm, in particular in the range of 125 µm to 300 µm. The total layer thickness includes the thickness of the substrate 13 as well as the thickness of all decorative layers 14.

[0179] In particular, it can be provided that the fiber mat 11 comprises essentially 50% natural fibers and 50% thermoplastic fibers, in particular that the fiber mat 11 comprises at least 33% natural fibers and / or at least 33% thermoplastic fibers. In a particularly preferred embodiment, the fiber mat 11 comprises approximately half natural fibers and the other half thermoplastic fibers. The thermoplastic fibers are preferably polypropylene fibers. Polypropylene fibers can be produced particularly easily and cost-effectively. Furthermore, recycled polypropylene can be used to produce the fibers.

[0180] Preferably, the natural fiber comprises a fiber type or mixture of fiber types selected from: hemp fiber, flax fiber, jute fiber, kenaf fiber, and coconut fiber. However, other natural fiber types are also conceivable.

[0181] It is preferred that the fiber mat 11, in particular the uncalibrated fiber mat 11, in step b) has a thickness in the range from 2 mm to 25 mm, in particular from 6 mm to 15 mm. Fig. The fiber mat 11 shown in Figure 2a is still in an uncalibrated or unpressed state.

[0182] By the subsequent pressing in step d), which is Fig. As shown in Figure 2b, the thickness of the fiber mat 11 decreases due to the pressing pressure, indicated by the two arrows, and the melting of the thermoplastic fibers due to thermal heating, indicated by the thermometer. Thus, a type of compaction takes place, which increases the stability of the fiber mat 11.

[0183] Preferably, in step d), the press, in particular the calibration press, comprises two planar, heatable plates or surface stamps, by means of which the thermal heating of the fiber mat 11 and the decorative sheet 12 takes place. The planar plates or surface stamps of the press ensure that the fiber mat 11 is pressed evenly over its entire surface.

[0184] Preferably, it may be possible for the pressing in step d) to take place at a temperature in a range from 150°C to 250°C, in particular in a range from 170°C to 230°C, particularly preferably in a range from 180°C to 210°C. The choice of temperature preferably depends on the thickness of the fiber mat 11 and the fibers used.

[0185] Furthermore, it is preferably provided that the pressing in step d) is carried out with a pressing force in a range of 180 kN to 220 kN, in particular in a range of 185 kN to 210 kN, preferably wherein the pressing force is built up continuously or gradually over time by closing the press, or the pressing force is reached suddenly. The pressing force preferably depends on the thickness of the fiber mat 11 and the fibers used.

[0186] Preferably, the pressing in step d) can be carried out for a duration ranging from 30 seconds to 180 seconds. The duration preferably depends on the material thickness of the decorative sheet 12 and the fiber mat 11.

[0187] In particular, it is possible that in step d), the decorative sheet 12 forms a material bond with the fiber mat 11, in particular with the thermoplastic fibers of the fiber mat 11, in particular due to thermal heating. As already described above, the thermal heating melts the thermoplastic matrix of the substrate 13 of the decorative sheet 12 and the thermoplastic fibers. This is followed by a sinking of the plasticized substrate 13 toward the fiber mat 11, so that the material of the substrate 13 can mix with the material of the thermoplastic fibers to form a plastic mass. During subsequent cooling, a material bond is formed.

[0188] Furthermore, it is preferably provided that in step d) the material of the substrate 13, in particular the polypropylene of the substrate 13, is softened and / or plasticized by the thermal heating and sinks from the upper boundary region 40 of the fiber mat 11 towards the lower region 41 of the fiber mat 11, whereby a partial decoration of the natural fibers arranged in the upper boundary region 40 of the fiber mat 11 occurs, resulting in a mottled appearance. The material of the substrate 13 and the thermoplastic fibers, which has been plasticized into a plastic mass, forms the background. Depending on the color of the substrate 13 or the thermoplastic fibers, the background of the fiber mat 11 or the molded part 10 is also predetermined accordingly. Black polypropylene is frequently used here. However, all other colors are also conceivable. It is also possible for the substrate 13 and / or the thermoplastic fibers to be transparent or translucent.The decorated natural fibers generally differ from and stand out from the background. In particular, the natural fibers are often decorated with a metallic finish, giving them a grayish, slightly shiny appearance. However, coloring the natural fibers with a layer of color as a decorative layer 14 is also conceivable.

[0189] It is preferably provided that in step d) the color of the substrate 13 of the decorative web 12 and / or the color of the thermoplastic fibers essentially represents the visible background color of the mottled appearance.

[0190] In particular, it is provided that in step d) the thermoplastic fibers are softened and / or plasticized to form a melt, so that the density of the thermoplastic fibers increases due to this melt and the melt sinks into the fiber mat 11 starting from the upper boundary region 40 of the fiber mat 11 in the direction of the lower region 41 of the fiber mat 11, whereby the natural fibers, in particular those which do not melt, partially protrude from the melt.

[0191] It is furthermore also preferably possible that in step d) the decorative layer 14 sinks and / or infiltrates in the upper boundary region 40 of the fiber mat 11 due to the sinking of the substrate 13 of the decorative web 12 into the fiber mat 11.

[0192] After pressing in step d), as in Fig.As shown in Figure 2b, the decorated fiber mat 11 is formed in step e). Preferably, after step d) and before step e), the decorated fiber mat 11 is removed from the press and placed in a mold. The forming in step e) preferably serves to three-dimensionally deform the decorated fiber mat 11 to provide a decorated molded part 10. For example, this can be a vehicle interior part.

[0193] As in Fig. As can be seen in Figure 2c, the mold has two mold halves 20, 21. These are preferably two mold halves 20, 21 that are not heated. "Not heated" in this context means that the mold halves have a temperature below the softening temperature of the thermoplastic matrix. However, it may also be possible for the mold halves 20, 21 to be actively or passively tempered.

[0194] Preferably, in step e) the forming takes place at a pressing force in a range of 550 kN to 650 kN, in particular in a range of 560 kN to 640 kN.

[0195] In particular, it is possible that in step e) the forming takes place with a time duration in a range of 30 seconds to 60 seconds.

[0196] It can also be provided that in step e) the molding takes place at a maximum temperature of 80°C. For this purpose, the mold halves 20, 21 can be heated accordingly, for example by means of heating elements.

[0197] It is preferably provided that the fiber mat 11 is deformable after step d) due to the thermal heating and is deformed in step e) and then solidified into a molded part 10 by cooling.

[0198] In particular, it can be provided that in step e), the melted substrate 13 of the decorative sheet 12 and the melted thermoplastic fibers of the fiber mat 11 solidify, thus causing the thermoplastic materials to shrink. This ensures that several natural fibers, or a larger proportion of the natural fibers, reach the surface of the molded part 10. This offers the advantage that the feel and the characteristic visual appearance of the fiber mat 11 are retained.

[0199] Furthermore, it can also be provided that in step e) an additional trimming takes place in the mold or that after step e) a separate trimming of the molded part 10 takes place by means of a knife and / or laser, so that the molded part 10 is adapted to the final shape.

[0200] It is also possible that after step e) the following step is carried out: f) Back-injecting the molded part 10 with a plastic mass, preferably in the mold or in an injection molding machine, in order to attach mounting elements and / or reinforcing elements.

[0201] The attachment of mounting elements facilitates the assembly of the molded part 10 and the reinforcing elements ensure that the molded part 10 receives additional stability.

[0202] In particular, it is also possible that the decorated fiber mat 11 after step d) and / or the decorated molded part 10 after step e) has a thickness in the range from 1 mm to 4 mm, in particular from 1.5 mm to 3.5 mm.

[0203] In Fig. 2d schematically shows a decorated molded part 10 which is produced according to a method according to Fig.1. The molded part 10 comprises the fiber mat 11 and the decorative sheet 12, whereby the decorative sheet 12 is no longer visible due to the previous plasticization of the substrate 13. Rather, the natural fibers are in the upper boundary area 40, which in Fig. 2d, is decorated over its entire surface. However, it may also be possible for the natural fibers in the upper boundary region 40 to be only partially decorated. In particular, it is provided that the upper boundary region 40 amounts to a maximum of 50%, preferably a maximum of 33%, of the total thickness of the fiber mat 11, in particular of the decorated molded part 10.

[0204] In the lower area 41, in the design according to Fig.2d, the thermoplastic fibers and the substrate 13 of the decorative sheet 12 are fused to form a solid composite. In particular, it is provided that the lower region 41 amounts to a maximum of 67%, preferably a maximum of 50%, of the total thickness of the fiber mat 11, in particular of the decorated molded part 10.

[0205] It is preferably provided that the decorated molded part 10 has a thickness in the range from 1 mm to 4 mm, in particular from 1.5 mm to 3.5 mm.

[0206] Advantageously, the decorated molded part 10 has a mottled appearance due to the at least partial decoration of the natural fibers in the upper boundary region 40, in particular, wherein the at least partially decorated natural fibers stand out from the background, preferably wherein the background is essentially formed by the thermoplastic composite of the fused thermoplastic fibers and the substrate 13 of the decorative web 12. This gives the molded part 10 a visually appealing appearance and distinguishes it significantly from conventional fiber mats.

[0207] Fig. Figure 3 shows a microscope image of the visible side of the decorated molded part 10. This is a reflected light image with illuminant type II at 50x magnification. Fig.Light-colored natural fibers can be seen in Figure 3. These are natural fibers 15 decorated with a metal layer. The dark areas represent the background, i.e., the solidified composite of substrate 13 and thermoplastic natural fibers.

[0208] Fig. 4 shows another microscope image of the visible side of the decorated molded part 10. In the image according to Fig. 4 is a reflected light image taken with illuminant II at 50x magnification. In contrast to the Fig. The photograph shown in Figure 3, in which natural fibres 15 predominantly decorated with a metal layer can be seen, are shown in the Fig.4 depicts both natural fibers 15 decorated with a metal layer and natural fibers 16 coated with thermoplastic, particularly polypropylene. Here, too, the light-colored natural fibers 15 are those decorated with a metal layer. The dark natural fibers 16 are those coated with the thermoplastic or polypropylene.

[0209] Fig. 5 shows another microscope image of the visible side of the decorated molded part 10. In the image according to Fig. 5 is a photograph taken in reflected light using illuminant II at 50x magnification. Similar to Fig. 4, are also at Fig. 5, the natural fibers are coated with both a metal layer and a thermoplastic, particularly polypropylene. Here, too, the light-colored natural fibers 15 are those decorated with a metal layer. The dark natural fibers 16 are those coated with the thermoplastic or polypropylene.

[0210] Fig. Figure 6 shows a microscope image of the visible side of the decorated molded part 10, wherein a first region 30, in particular the decorated region, is arranged next to a second region 31, in particular the undecorated region. The image is an image taken in reflected light using illuminant type II at a magnification of 50x. In the case of the decorated molded part 10 according to Fig.6 is a molded part 10 which is only decorated in certain areas. This means that the decoration is at least partially present in a first area 30, in particular the decorated area, and is not present in a second area 31, in particular the undecorated area. In the first area 30, it is clearly visible how the natural fibers 15 have a metallic luster, which is caused by the decoration of a metal layer. In the second area 31, however, this luster is not present. Instead, the natural fibers 16 appear dark in this area, since they are covered by the thermoplastic, in particular propylene. Furthermore, in Fig. 6 also shows the transition between the first region 30, in particular the decorated region, and the second region 31, in particular the undecorated region. To a good approximation, this can be described as a sharp-edged decoration, since the transition region is comparatively small.

[0211] Fig.Figure 7 shows another micrograph of the visible side of the decorated molded part 10, wherein a first region 30, in particular the decorated region, is arranged next to a second region 31, in particular the undecorated region. The image is a reflected light image using illuminant type II at a magnification of 15x. Essentially, the statements regarding Fig. 6 also for the Fig. 7. Fig.Figure 7 once again illustrates the visual appearance of the decorated molded part 10. At 15x magnification, it is clearly visible that in the first area 30, particularly the decorated area, the natural fibers 15 appear light, and in the second area 31, particularly the undecorated area, the natural fibers 16 appear dark compared to the decorated area. This creates the mottled appearance mentioned above. The natural fibers 16 in the second area 31, particularly the undecorated area, form the background, and the natural fibers 15 in the first area 30, particularly the decorated area, form the foreground. It is thus also possible to create different decorations in the form of one or more motifs.A motif can be, for example, a graphically represented outline, a figurative representation, an image, a visually recognizable design element, a symbol, a logo, a portrait, a pattern, a continuous pattern, an alphanumeric character, a code, a code pattern, a cryptographic pattern, a text, a color design, and the like. The motif can also be customized. In particular, it is intended that the decorated area forms one or more motifs. List of reference symbols 1 Providing a decorative strip 2 Providing a fiber mat 3 Inserting the fiber mat and the decorative sheet into a press 4 Pressing of the fiber mat and the decorative sheet under thermal heating 5 forms of the decorated fiber mat in a mold 10 molded part 11 Fiber mat 12 decorative strips 13 Substrat 14 decorative layer 15 decorated natural fibers, light natural fibers 16 thermoplastic coated natural fiber, dark natural fiber 20 mold halves 21 mold half 30 first area 31 second area 40 upper limit range 41 lower area

Claims

[1] Method for producing a decorated molded part (10), wherein the molded part (10) comprises a fiber mat (11) which comprises natural fibers and thermoplastic fibers, wherein the method comprises the following steps, in particular in the following order: a) providing a decorative sheet (1, 12), wherein the decorative sheet (12) comprises a substrate (13) and at least one decorative layer (14) applied to the substrate (13); b) providing a fiber mat (2, 11), wherein the fiber mat (11) comprises natural fibers and thermoplastic fibers; c) inserting the fiber mat (11) and the decorative web (12) into a press (3), in particular into a calibration press, wherein the decorative web (12) is arranged on the fiber mat (11) in such a way that the at least one decorative layer (14) of the decorative web (12) faces the fiber mat (11); d) pressing the fiber mat (11) and the decorative web (12) under thermal heating (4) so that the substrate (13) of the decorative web (12) fuses with the thermoplastic fibers of the fiber mat (11) and the decorative layer (14) of the decorative web (12) at least partially decorates the natural fibers arranged in an upper boundary region (40) of the fiber mat (11) to provide a decorated fiber mat (11); e) forming the decorated fiber mat (11) in a mold (5) to obtain a decorated molded part (10). [2] Method according to claim 1, characterized by that the natural fiber comprises a fiber type or mixtures of fiber types selected from: hemp fiber, flax fiber, jute fiber, kenaf fiber, coconut fiber. [3] Method according to claim 1 or 2, characterized by that the fiber mat (11), in particular the uncalibrated fiber mat (11), in step b) has a thickness in the range from 2 mm to 25 mm, in particular from 6 mm to 15 mm. [4] Method according to one of claims 1 to 3, characterized by that the decorative sheet (12) has a total layer thickness in the range from 100 µm to 500 µm, in particular in the range from 125 µm to 300 µm. [5] Method according to one of claims 1 to 4, characterized by that to provide the decorative sheet (12) in step a), the following steps are carried out, in particular in the specified order: - providing the substrate (13); - applying the decorative layer (14) by means of printing and / or by means of transferring a transfer layer of a transfer film, in particular by means of hot stamping. [6] Method according to one of claims 1 to 5, characterized by that in step a) the decorative layer (14) is applied to the front and / or the back of the substrate (13). [7] Method according to one of claims 1 to 6, characterized by that in step a) a protective lacquer layer is applied to the front side of the substrate (13). [8] Method according to one of claims 1 to 7, characterized by that the substrate (13) comprises a material or combination of materials selected from: polypropylene (PP), polyethylene (PE), polyolefins, polyethylene terephthalate (PET), biodegradable biopolymers, in particular polylactide (PLA). [9] Method according to one of claims 1 to 8, characterized by that the substrate (13) comprises polypropylene (PP) as material. [10] Method according to one of claims 1 to 9, characterized by that the fiber mat (11) essentially comprises 50% natural fibers and 50% thermoplastic fibers, in particular that the fiber mat (11) comprises at least 33% natural fibers and / or at least 33% thermoplastic fibers. [11] Method according to one of claims 1 to 10, characterized bythat after step b) and before step c) the fiber mat (11) is placed in a press, in particular a calibration press, and the fiber mat (11) is calibrated without the decorative web (12). [12] Method according to one of claims 1 to 11, characterized by that in step d) the press, in particular the calibration press, has two planar, heatable plates or surface stamps by means of which the thermal heating of the fiber mat (11) and the decorative web (12) takes place. [13] Method according to one of claims 1 to 12, characterized by that the pressing in step d) takes place at a temperature in a range from 150°C to 250°C, in particular in a range from 170°C to 230°C, particularly preferably in a range from 180°C to 210°C. [14] Method according to one of claims 1 to 13, characterized bythat the pressing in step d) is carried out with a pressing force in a range of 180 kN to 220 kN, in particular in a range of 185 kN to 210 kN, preferably wherein the pressing force is built up continuously or stepwise by closing the press or the pressing force is reached suddenly. [15] Method according to one of claims 1 to 14, characterized by that the pressing in step d) takes place with a duration in a range of 30 seconds to 180 seconds. [16] Method according to one of claims 1 to 15, characterized by that in step d) the decorative web (12) forms a material bond with the fiber mat (11), in particular with the thermoplastic fibers of the fiber mat (11), in particular due to thermal heating. [17] Method according to one of claims 1 to 16, characterized byin step d) the material of the substrate (13), in particular the polypropylene of the substrate (13), is softened and / or plasticized by the thermal heating and sinks from the upper boundary region (40) of the fiber mat (11) towards the lower region (41) of the fiber mat (11), whereby a partial decoration of the natural fibers arranged in the upper boundary region (40) of the fiber mat (11) takes place, so that a mottled appearance is created. [18] Method according to claim 17, characterized by that in step d) the color of the substrate (13) of the decorative web (12) and / or the color of the thermoplastic fibers essentially represents the visible background color of the mottled appearance. [19] Method according to one of claims 1 to 18, characterized bythat in step d) the thermoplastic fibers are softened and / or plasticized to form a melt, so that the density of the thermoplastic fibers increases as a result of this melt and the melt sinks into the fiber mat (11) starting from the upper boundary region (40) of the fiber mat (11) in the direction of the lower region (41) of the fiber mat (11), as a result of which the natural fibers, in particular those which do not melt, partially protrude from the melt. [20] Method according to one of claims 1 to 19, characterized by that in step d) as a result of the substrate (13) of the decorative web (12) sinking into the fiber mat (11), the decorative layer (14) sinks and / or infiltrates in the upper boundary region (40) of the fiber mat (11). [21] Method according to one of claims 1 to 20, characterized by that the upper limit range (40) is a maximum of 50%, preferably a maximum of 33%, of the total thickness of the fiber mat (11), in particular of the decorated molded part (10). [22] Method according to one of claims 1 to 21, characterized by that in step e) the molding tool has two mold halves (20, 21), in particular wherein the two mold halves (20, 21) are not heated. [23] Method according to one of claims 1 to 22, characterized by that in step e) the forming takes place at a pressing force in a range of 550 kN to 650 kN, in particular in a range of 560 kN to 640 kN. [24] Method according to one of claims 1 to 23, characterized by that in step e) the forming takes place with a time duration in a range of 30 seconds to 60 seconds. [25] Method according to one of claims 1 to 24, characterized by that in step e) the forming takes place at a maximum temperature of 80°C. [26] Method according to one of claims 1 to 25, characterized bythat the fiber mat (11) is deformable after step d) due to the thermal heating and is deformed in step e) and then solidified into a molded part (10) by cooling. [27] Method according to one of claims 1 to 26, characterized by that in step e) the melted substrate (13) of the decorative sheet (12) and the melted thermoplastic fibers of the fiber mat (11) solidify and thus a shrinkage of the thermoplastic materials occurs. [28] Method according to one of claims 1 to 27, characterized by that in step e) an additional trimming is carried out in the mold or that after step e) a separate trimming of the molded part (10) is carried out by means of a knife and / or laser, so that the molded part (10) is adapted to the final shape. [29] Method according to one of claims 1 to 28, characterized by that after step e) the following step is carried out: f) back-injecting the molded part (10) with a plastic mass, preferably in the mold or in an injection molding machine, in order to attach assembly elements and / or reinforcement elements. [30] Method according to one of claims 1 to 29, characterized by that the decorated fiber mat (11) after step d) and / or the decorated molded part (10) after step e) has a thickness in the range from 1 mm to 4 mm, in particular from 1.5 mm to 3.5 mm.

Images