METHOD FOR MANUFACTURED A PLASTIC VEHICLE PART

Description

[0001] The invention relates to a method and a device for manufacturing a polymeric vehicle attachment, a polymeric vehicle attachment and its use.

[0002] With increasingly stringent regulations on carbon dioxide emissions from motor vehicles, there is a strong drive to reduce vehicle weight and thus fuel consumption. Continuous advancements in plastics technology allow for the replacement of large sections of the metal body with correspondingly lighter elements made of polymeric materials. In particular, parts or even the entire window area can be replaced with polymeric components. In many cases, these exhibit comparable hardness, stability, and load-bearing capacity to a steel body window, despite their significantly lower weight. Furthermore, the weight reduction lowers the vehicle's center of gravity, which has a positive impact on handling. Molded parts made of polymeric materials can be manufactured in virtually any desired shape and geometry.

[0003] Many plastic components must meet various requirements and functions. Important parameters include stability, fracture behavior, scratch resistance, impact strength, and notched impact strength. Besides technical aspects such as the weight and strength of individual components, shape, geometry, and appearance are playing an increasingly important role. Especially in the automotive industry, design and aesthetic characteristics are just as important as mechanical properties.

[0004] An established method for creating optical effects is film insert molding (FIM). In this process, a suitable film is inserted into the injection mold and back-injected with a suitable plastic. This allows for the targeted and versatile manipulation and modification of the surface properties and geometry of polymeric materials. A method for producing polymeric add-on parts using film insert molding is known, for example, from WO2013 / 050208. An important prerequisite for the application of film insert molding is the use of temperature-stable films. Furthermore, any printed designs on the film must be sufficiently temperature-resistant to withstand back-injection with a liquid polymer such as polycarbonate. EP2689929A1 discloses the structure of a film suitable for film insert molding with a metal layer as a decorative element.

[0005] It is also known to apply decorative elements to polymer workpieces using hot stamping. For example, WO2016 / 096184A1 (a document under Article 54(3) EPC) discloses a method for manufacturing a polymer vehicle add-on part, which may consist of several polymer material phases. The decorative element is stamped onto an outer surface of the add-on part, where it is exposed to environmental influences. After hot stamping, the add-on part is coated with a protective layer to protect the decorative element from damage.

[0006] US7547372B1 discloses the structure of a hot stamping foil that is also suitable for use on vehicle add-on parts.

[0007] US 4 350 550 A discloses a method for decorating different areas of the front surface of a molded resin sheet with a decorative material in one area and a decorative coating in another area.

[0008] DE 199 40 244 A1 discloses a method for producing a foil-laminated plastic part using a hot stamping machine.

[0009] WO 2012 / 083007 A2 discloses a method for forming a polymer component assembly, comprising injection molding a first subcomponent, injection molding a second subcomponent and coupling the first subcomponent and the second subcomponent together to form the polymer component assembly.

[0010] EP 1 424 709 A1 discloses a method for producing a decorative molded object, which is designed as a resin molded object and is decorated with a color design image.

[0011] In DE 10 2013 000400 A1 a process for transfer lamination is disclosed.

[0012] The invention aims to provide a further method for manufacturing a polymer vehicle add-on part with a decorative element. The decorative element should be protected from external influences and enable an aesthetically pleasing and highly visible design of the window. Furthermore, the method should be easy to apply industrially.

[0013] The object of the invention is achieved by the method according to claim 1, a device according to claim 11, and a polymeric vehicle add-on part with a decorative element according to claim 12. Preferred embodiments are described in the dependent claims.

[0014] The inventive method for manufacturing a polymeric vehicle add-on part with a decorative element comprises at least the following process steps: (a) a first polymeric material phase is provided; (b) a decorative element is transferred from a carrier film to a first surface of the first polymeric material phase by hot stamping using a die; (c) a second polymeric material phase is applied to the first surface of the first polymeric material phase, so that the decorative element is arranged between the first polymeric material phase and the second polymeric material phase, in particular at the interface of the two material phases.

[0015] The polymeric attachment (or plastic attachment) according to the invention is preferably an external attachment, i.e., an attachment for the exterior of the vehicle, or an attachment for the vehicle interior. The attachment, if intended as an external attachment, is in particular a pane (especially a vehicle window pane, for example, a roof window, rear window, or side window), a pillar cover, a light cover, a radiator grille trim, a panel, a roof panel, a mirror housing, a frame element, a side strip, a sill, or a spoiler. The attachment, if intended for the interior, is, for example, a dashboard or control panel.

[0016] The invention enables, among other things, the optical enhancement and refinement of visible surfaces of plastic vehicle windows, the insertion of information (in the form of text or symbols), the representation of a variety of optical effects and freedom in the color design of the add-on part through a variety of available hot stamping foils.

[0017] The add-on part is fixed to the vehicle via one of its surfaces. The opposite surface then forms the visible surface in the installed position, accessible to the observer or user. For the purposes of the invention, this surface is referred to as the outer surface or outward-facing surface of the add-on part. The material phases can also be referred to as components of the add-on part.

[0018] At least one of the two polymeric material phases is transparent. The transparent material phase is designed to face outwards when the attachment is installed – thus, the outer surface of the attachment is the surface of the first material phase applied by the second material phase. The position of the decorative element behind the transparent material phase creates a glass-like impression with a depth effect, which is visually very appealing. Furthermore, the decorative element is protected from damage between the two material phases. These are significant advantages of the present invention.

[0019] In a preferred embodiment, one of the two polymeric material phases is opaque. Thus, the add-on component comprises a transparent and an opaque material phase. This enhances the visually appealing, glass-like appearance.

[0020] In the context of the invention, "transparent" means that an observer can see through the component and perceive objects located behind it. The transparent component can be colorless, colored, or tinted. The transmission of the transparent component in the visible spectral range is, for example, greater than or equal to 70%, preferably greater than or equal to 85%.

[0021] In the context of the invention, opaque means that an observer cannot see through the component. The transmission of the opaque component in the visible spectral range is therefore significantly reduced and is, for example, less than or equal to 10%, less than or equal to 5%, and in particular approximately 0%.

[0022] In a particularly advantageous embodiment, the first polymeric material phase, onto whose surface the decorative element is applied, is transparent, while the second polymeric material phase is opaque. Initially providing the transparent material phase and subsequently applying the opaque material phase offers the advantage of high optical quality for the component. The reverse process carries the risk that, when spraying on the hot, transparent polymer mass, parts of the already solidified opaque polymer mass (more precisely, the dissolved colorants within it) will be dissolved and "washed out." This can cause the dissolved colorants to settle as black or gray clouds within the otherwise transparent material phase, diminishing the optical appearance, especially if these clouds are located in front of the decorative element.

[0023] However, it is also possible, and in some cases desirable, for the first polymeric material phase to be opaque and the second polymeric material phase to be transparent. In this case, the injection points of the transparent material phase should be located far enough away from the decorative element so that any clouding in the transparent material phase is not carried over onto the decorative element. The clouding will then be less noticeable to the viewer and may be acceptable in some cases.

[0024] Each of the two material phases, and thus also the attachment as a whole, is typically designed to be essentially planar or plate-like and has two main surfaces and a circumferential side edge. One of the main surfaces of the first material phase is the first surface according to the invention, onto which the decorative element is applied.

[0025] The transparent and opaque material phases can be essentially identical. In this case, the entire component is opaque, with the transparent phase creating a glass-like optical impression. However, the opaque component can also be present only in certain areas of the component. This is the case, for example, with window panes, where the opaque component is typically located around the perimeter, allowing the pane to be bonded to the vehicle body invisibly to the observer.

[0026] According to the invention, the decorative element is applied to the first material phase by hot stamping. Hot stamping is also frequently referred to as lift stamping or by the English term "hot stamping". The carrier film with the decorative element is arranged such that the decorative element faces the attachment, in particular the first surface of the attachment. The die then acts on the surface of the carrier film facing away from the decorative element, so that the decorative element is pressed against the first surface. The carrier film is then removed, leaving the decorative element on the first surface.

[0027] Preferably, the carrier film is designed as a film web on rolls and carries a multitude of decorative elements, with each decorative element positioned under the die (i.e., between the die and the component) during hot stamping. The rolls advance the film web, allowing the next decorative element to be placed under the die and applied to the next component. This enables economical industrial mass production. The individual decorative elements can be arranged separately on the carrier film. In practice, however, the entire carrier film can also be coated with a continuous single- or multi-layer decorative coating, in which the individual decorative elements are not separated from one another. The individual decorative elements are only separated from the rest of the coating during hot stamping by the adhesive effect on the component, thus becoming individualized.The shape of the decorative element is determined by the design of the stamp's contact surface. However, the decorative elements can also be customized on the carrier film itself through perforations or cuts in the overall coating, which facilitates removal.

[0028] The stamp operates at an elevated temperature, which is transferred to the carrier film and the decorative element, thus promoting adhesion of the decorative element to the attachment. The stamp preferably operates at a temperature of 120 °C to 250 °C, and particularly preferably at 140 °C to 200 °C. This achieves especially good results. The exact temperature also depends on the film used and can be determined by a person skilled in the art from the manufacturer's specifications or through routine preliminary tests.

[0029] The contact surface of the stamp preferably contains or is made of silicone. However, the contact surface can also contain or be made of natural or synthetic rubber or other elastomers. The advantage lies in the soft design of the contact surface, which prevents damage to the attached part. The contact surface can also be made of metal.

[0030] In an advantageous embodiment, the stamp exerts a pressure of 15 kg / cm² to 50 kg / cm² on the first surface, preferably 20 kg / cm² to 40 kg / cm², and particularly preferably 25 kg / cm² to 35 kg / cm². This ensures particularly good adhesion of the decorative element while still protecting the attached component.

[0031] The contact time of the stamp on the first surface for applying the decorative element is preferably at least 1 second, particularly preferably at least 2 seconds. The contact time can, for example, range from 1 second to 10 seconds, preferably from 2 seconds to 4 seconds. This is advantageous with regard to both good adhesion and a short cycle time.

[0032] The decorative element is preferably designed as a film. The decorative element is particularly preferably designed as a multi-layered film. In a particularly advantageous embodiment, the decorative element comprises at least one decorative layer and one adhesive layer. The layers are arranged on the carrier film in the specified sequence with increasing distance from the carrier film. The decorative element comes into contact with the attachment via the adhesive layer. Once the decorative element has been transferred to the attachment, the sequence, with increasing distance from the first surface, is: adhesive layer - decorative layer.

[0033] The adhesive layer creates adhesion between the decorative element and the attachment. This adhesion is stronger between the decorative element and the attachment than between the decorative element and the carrier film, causing the decorative element to detach from the carrier film. The adhesive layer permanently and securely fixes the decorative element to the surface of the polymeric material phase. In a preferred embodiment, the adhesive layer contains an acrylic-based adhesive. This results in particularly good adhesion through the formation of covalent bonds and van der Waals forces. This effect is especially pronounced when the attachment contains polycarbonate. Alternatively, the adhesive layer can also contain other suitable materials that promote adhesion, such as polyurethane or epoxy resin. The adhesive layer preferably has a thickness of 0.1 µm to 5.0 µm.This achieves good adhesion without excessively increasing the thickness of the decorative element, which would detract from its visual appearance. The adhesive layer is preferably transparent so that the view of the attached part is not obstructed.

[0034] The decorative layer provides the actual visual effect of the ornamental element. It can therefore also be referred to as the color layer. The decorative layer is a polymeric layer, meaning it contains a polymer. A variety of polymers are suitable as base materials for the decorative layer, for example, polymethyl methacrylate. The decorative layer preferably has a thickness of 1.0 µm to 10.0 µm. To create the visual impression of the ornamental element, the decorative layer can, for example, be printed with a design or contain embedded colorants. Colorants are pigments or dyes that can be inorganic or organic and can be colored or achromatic.Suitable printing inks or inlays include, for example, temperature-stable organic pigments or dyes (such as urethane-acrylate polymers, azo dyes, or polycyclic compounds) or inorganic pigments (such as carbon, titanium dioxide, carbon black, cinnabar, bismuth (bismuth vanadate), spinel pigments, lead, mercury, zirconium, iron, cadmium, copper, cobalt, nickel, and chromium pigments; aluminum silicates (ultramarine)). The decorative layer can be monochrome or multicolored, contain different shades (e.g., different shades of gray), be designed with full-surface or partial surface effects, and / or be executed as a metallic effect.

[0035] The decorative layer can be the top layer of the decorative element and be in contact with the second material phase. Preferably, however, the multi-layered decorative element contains a protective layer in addition to the adhesive layer and the decorative layer. The decorative element then comprises at least the protective layer, the decorative layer, and the adhesive layer, which are arranged on the carrier film in the specified order with increasing distance from the carrier film. Once the decorative element is transferred to the attached component, the order, with increasing distance from the first surface, is: adhesive layer - decorative layer - protective layer.

[0036] The protective layer protects the decorative layer from mechanical damage during the injection molding of the second material phase. The protective layer is preferably a protective lacquer. It preferably contains an acrylic polymer, polymethyl methacrylate (PMMA), or polyurethane (PU). The protective layer preferably has a thickness of 0.5 µm to 5.0 µm, which yields particularly good results.

[0037] The total thickness of the decorative element is preferably up to 100 µm, particularly preferably from 2 µm to 20 µm, and most preferably from 4 µm to 10 µm. This achieves a distinct optical effect.

[0038] The size and design of the decorative element can be freely chosen according to the requirements in each individual case.

[0039] The carrier film typically has a thickness of 10 µm to 500 µm, preferably 10 µm to 50 µm, and particularly preferably 15 µm to 30 µm. In principle, the carrier film can also be thicker (which, however, increases the cost) or thinner (as long as sufficient stability is ensured). The carrier film preferably contains polyethylene terephthalate (PET), polycarbonate (PC), polybutylene terephthalate (PBT), styrene-acrylonitrile (SAN), or mixtures or copolymers thereof, such as polycarbonate-polybutylene terephthalate (PBT / PC). This ensures sufficient stability.

[0040] In an advantageous embodiment, a release layer is arranged between the carrier film and the decorative element. This release layer facilitates the removal of the decorative element from the carrier film after hot stamping. The release layer has, for example, a thickness of 0.1 µm to 5.0 µm.

[0041] In a preferred embodiment, at least the surface of the transparent polymeric material phase facing away from the decorative element (the intended outer surface of the attachment) is provided with a protective coating. Alternatively, the entire surface of the attachment can be provided with the protective coating. The protective coating increases the durability of the surface, in particular its scratch resistance and weather resistance, and thus reduces wear. In a preferred embodiment, the protective coating is applied by means of flood coating ( flow coating ) applied. This allows for a homogeneous coating with short cycle times. Alternatively, other coating methods are also applicable, such as dip or spray coating or Inmould Coating- Procedure.

[0042] The protective coating is also frequently referred to as a scratch-resistant coating, wear-resistant coating, or, in English, a "hardcoat." Preferably, protective coatings containing thermally curing or UV-curing lacquers are used, particularly those based on polysiloxanes, polyacrylates, polymethacrylates, polyurethanes, or mixtures or copolymers thereof. The protective coating can have one or more separately applied layers and preferably has a total layer thickness of 1 µm to 50 µm, particularly preferably 2 µm to 25 µm. It provides the component with good scratch resistance, weather resistance, and chemical resistance. The protective coating can also contain UV blockers, preservatives, and components to increase scratch resistance, such as nanoparticles. Additionally, the protective coating can also provide decorative functions, such as gloss or beading effects.The protective coating is preferably cured by heating and / or UV radiation after application.

[0043] The protective coating can consist of a single layer. However, it can also have several individual layers. Such a multi-layered protective coating comprises, below the actual... Hardcoat preferably an adhesion-promoting coating, a so-called Primer. "Below" means that the primer is placed between the attachment and the actual part. Hardcoat The primer is arranged in a specific configuration. It preferably contains polymethyl methacrylate, UV absorbers, and alcoholic solvents. The primer layer thickness is, for example, from 0.2 µm to 8.0 µm, preferably from 1.0 µm to 4.0 µm.

[0044] The two material phases of the attachment can, in principle, be made from any polymer that provides sufficient stability. Preferably, the two material phases of the attachment contain polyethylene (PE), polycarbonate (PC), polypropylene (PP), polystyrene, polybutadiene, polynitrile, polyester, polyurethane, polymethyl methacrylate (PMMA), polyacrylate, polyamide, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS), styrene acrylonitrile (SAN), acrylonitrile styrene acrylate (ASA), acrylonitrile butadiene styrene-polycarbonate (ABS / PC), PET / PC, PBT / PC, or copolymers or mixtures thereof. PC, PMMA, SAN, ASA, PET, or copolymers or mixtures thereof are particularly preferred. This is especially advantageous with regard to transparency, processing, strength, weather resistance, and chemical resistance.

[0045] The material phases can contain inorganic or organic fillers, preferably SiO2, Al2O3, TiO2, clay minerals, silicates, zeolites, glass fibers, carbon fibers, glass beads, organic fibers, and / or mixtures thereof. The fillers can further increase the stability of the component. In addition, the fillers can reduce the proportion of polymeric materials and thus lower manufacturing costs.

[0046] If a material phase is opaque, it contains at least one colorant. The colorant is responsible for the component's opacity. Inorganic or organic dyes and / or pigments can be used as colorants. The colorant can be colored or achromatic. Suitable colorants are known to those skilled in the art and can be found, for example, in the... Colour Index the British Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists The process can be looked up. A black pigment is preferably used as the colorant, for example carbon black, aniline black, bone black, iron oxide black, spinel black and / or graphite. This results in a black, opaque material phase.

[0047] The thickness of each material layer is, for example, from 0.5 mm to 20 mm. In particular, the transparent, outward-facing material layer should have a thickness of at least 1 mm to ensure good stability of the decorative element. The thickness of the transparent, outward-facing material layer is preferably from 1 mm to 10 mm, and more preferably from 3 mm to 7 mm. The thickness of the non-outward-facing material layer is preferably from 0.5 mm to 7 mm, and more preferably from 1 mm to 5 mm.

[0048] The provision of the first material phase and the application of the second material phase are carried out by injection molding. For the purposes of this invention, the term "injection molding" is to be interpreted broadly and encompasses all processes in which liquefied polymeric material is injected into a mold cavity and cured. In addition to classic injection molding, it also includes further developments such as injection compression molding. A carrier mold, which forms part of the mold cavity and supports the component during its manufacture, is preferably moved between the two injection molding devices for producing the two material phases, for example, by means of indexable platen, rotary table, or indexable platen technology, preferably by means of an indexable platen or a rotating cube. This moves the first polymeric material phase between process steps (a) and (c).Between the two injection molding steps for producing the first and second material phases, a hot stamping device is moved and positioned relative to the first material phase so that the first material phase can be decorated with the decorative element. This relative movement can be achieved by moving the first material phase or the hot stamping device, or in principle, by a combination of both.

[0049] The invention further comprises a device suitable for carrying out the described method. The device according to the invention for manufacturing a polymeric vehicle add-on part comprises a carrier mold, a means for producing a first polymeric material phase in the carrier mold or in a cavity formed using the carrier mold, a hot stamping agent that can be positioned relative to the provided first material phase such that a first surface of the first material phase can be stamped with a decorative element, and a means for producing a second polymeric material phase on the first surface of the first material phase. The carrier mold is a mold in or on which the add-on part is arranged during the phases of its manufacture and by which it is supported.

[0050] The means for producing the first polymeric material phase is a first injection molding device, and the means for producing the second polymeric material phase is a second injection molding device. Each injection molding device comprises means for liquefying and injecting a polymer mass, as well as a mold suitable for interacting with the carrier mold to form the complete injection mold (cavity), which contains the

[0051] The geometry of the workpiece to be produced is determined. The carrier mold is movably mounted, and the arrangement of the two injection molding units is such that the carrier mold can be moved from a first position, assigned to the first injection molding unit, to a second position, assigned to the second injection molding unit. The device includes means for moving the carrier mold from the first to the second position. A position is considered assigned to an injection molding unit if it is suitable for filling the carrier mold, or the cavity formed by the carrier mold and the counter-mold of the injection molding unit, with the injection molding compound using said injection molding unit. The actual injection process is typically preceded by a relative movement of the injection molding unit towards the carrier mold to make contact with it, thereby forming the actual injection mold (cavity).

[0052] The positioning of the hot stamping material relative to the first material phase can be achieved by moving the hot stamping material or the injection mold, or in principle by a combination of both.

[0053] In a first preferred embodiment, the injection mold is mounted on a rotating platen that is rotatable about a spatial axis. Typically, the two injection molding units are arranged opposite each other, so that the carrier mold located on one side of the rotating platen can be moved from the first position to the second position by a rotation of approximately 180°. Another carrier mold is typically arranged on the other side of the rotating platen. When the rotating platen is rotated to move the first carrier mold to the second position after the injection of the first material phase, the second carrier mold automatically moves to the first position, so that the first material phase of the next component can be injected into the second carrier mold simultaneously with the production of the second material phase in the first carrier mold.The hot stamping medium is mounted on a movable conveyor system and can be inserted between the first injection molding unit and the carrier mold, or between the second injection molding unit and the carrier mold, to apply the decorative element to the first material layer before the second material layer is injected. After the second material layer is formed, the decorative element is removed from the carrier mold. The carrier mold is then ready for the next cycle.

[0054] In a second preferred embodiment, the carrier mold is mounted on a rotating cube that is rotatable about a spatial axis. The two injection molding units are preferably arranged opposite each other. The hot stamping agent is arranged essentially perpendicular to the axis between the injection molding units. The carrier mold, located on one side of the rotating cube, can be moved from a first position, associated with the first injection molding unit, to a second position, associated with the hot stamping agent, by a rotation of approximately 90°. This second position is suitable for applying the decorative element to the first material phase using the hot stamping agent. A further rotation of approximately 90° moves the carrier mold to a third position, associated with the second injection molding unit. Another rotation of approximately 90° moves the carrier mold to a fourth position, which is preferably used for removing the decorative element from the carrier mold.Preferably, additional support forms are arranged on the other sides of the rotating cube, so that several of the aforementioned positions are simultaneously occupied by different support forms, allowing the production of one component to begin before the production of the preceding components is completed. Instead of a rotating cube, other rotatable tools can also be used, for example, a plate on a turntable, although fewer support forms can be arranged in this case.

[0055] The described processes are economical manufacturing methods that are particularly suitable for mass production.

[0056] The device according to the invention is suitable for carrying out the described method, and the method is preferably carried out using the device according to the invention. The details described above in connection with the method therefore apply equally to the device and vice versa.

[0057] The invention further comprises a polymeric vehicle add-on part with a decorative element, comprising a first polymeric material phase, a second polymeric material phase, and a decorative element arranged between the two polymeric material phases, which is applied to a first surface of the first polymeric material phase or the second polymeric material phase by hot stamping, wherein at least the first polymeric material phase or the second polymeric material phase is transparent, and wherein the first polymeric material phase and the second polymeric material phase are produced by injection molding. The polymeric add-on part according to the invention is produced, or can be produced, in particular by the method according to the invention. The decorative element is arranged at the interface between the first and second material phases.

[0058] The details and preferred embodiments described above in connection with the method and the apparatus apply equally to the vehicle add-on part according to the invention. In particular, the add-on part has the described protective coating at least on the surface of the transparent material phase facing away from the decorative element.

[0059] The invention further encompasses the use of the polymeric vehicle add-on component according to the invention as a radiator grille cover, pillar cover, trim panel, roof panel, vehicle window, light cover, mirror housing, frame element, side trim, sill, spoiler, instrument panel, or dashboard. Due to their high weather resistance and scratch resistance, the vehicle add-on components according to the invention are particularly suitable as exterior add-on components and are preferably used as such, for example, as radiator grille covers, pillar covers, trim panels, roof panels, vehicle windows, light covers, mirror housings, frame elements, side trim, sills, or spoilers, but can also be used in the vehicle interior, for example, as an instrument panel or dashboard.In the use according to the invention, the transparent material phase of the attachment is turned outwards - the surface of the transparent material phase facing away from the decorative element thus forms the outer surface of the attachment, while the attachment is fastened to the vehicle via the opaque material phase, if one is present.

[0060] The invention is explained in more detail with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.

[0061] They show: Fig. 1 a step-by-step representation of an embodiment of the method according to the invention, Fig. 2 a cross-section through an embodiment of a carrier film with decorative element, Fig. 3 a cross-section through an embodiment of the polymeric attachment part according to the invention with decorative element, Fig. 4 a cross-section through an embodiment of the device according to the invention during the method according to the invention in a step-by-step representation, Fig. 5 a top view of a further embodiment of the device according to the invention and Fig. 6 an embodiment of the method according to the invention based on a flowchart.

[0062] Figur 1 Figure 1 shows a cross-section of a polymeric component 1 at various points in time during the inventive process for its production: (a) before hot stamping of the first material phase 1a, (b) during hot stamping, (c) after hot stamping, and (d) after application of the second material phase 1b. The polymeric component 1 is, for example, a plastic window for a motor vehicle, such as a rear side window. However, the polymeric component 1 can also be another vehicle component, such as a pillar cover, a spoiler, or a light cover.

[0063] First, a first material phase 1a is produced by injection molding, for example, a transparent disc- or plate-like material phase with a thickness of 4 mm made of polycarbonate. The transparent first material phase 1a is then positioned in front of a die 4 ( Fig. 1(a) ), wherein a first surface I of material phase 1a faces the die 4. A decorative element 2 is positioned on a carrier film 5 between the die 4 and material phase 1a. The carrier film 5 is a film web with a plurality of decorative elements 2, which is wound onto two rolls (not shown). This allows the carrier film 5 to be transported further, so that another decorative element 2 is conveyed under the die 4 and made available for application to another material phase 1a.

[0064] The decorative element 2 is designed as a multilayer film, which is described in more detail below. For clarity, the various decorative elements 2 are shown as discrete elements on the carrier film 5. However, it is also possible that the multilayer film essentially covers the entire surface of the carrier film 5, with the individual decorative elements 2 detaching from the overall film due to adhesion to the first material layer 1a. This detachment can also be facilitated by incisions or perforations in the overall film.

[0065] The stamp 4 acts on the surface of the carrier film 5 facing away from the decorative element 2, so that the decorative element 2 is pressed against the first surface I of the material phase 1a ( Fig. 1(b) ), for example, with a pressure of 30 kg / cm². The stamp 4 has a temperature of, for example, approximately 160°C. The contact time of the stamp 4 with the surface I is, for example, 2.5 s. The contact of the stamp 4 is typically achieved by pressing it against the material phase 1a, but can alternatively or additionally be achieved by pressing the material phase 1a against the stamp 4.

[0066] Subsequently, stamp 4 and material phase 1a are separated again and the carrier film 5 is removed, leaving the decorative element 2 on the surface I of material phase 1a ( Fig. 1(c) ).

[0067] Subsequently, a second material phase 1b is applied to the first surface of the first material phase 1a by injection molding, so that the decorative element 2 is arranged at the interface between the first material phase 1a and the second material phase 1b ( Fig. 1(d) ). This results in the attachment part 1 according to the invention. The opaque phase consists, for example, of a PC / ABS mixture colored black by pigments and has a thickness of 2.5 mm.

[0068] The attachment 1 can then be provided with a protective coating, which is, for example, two-layered and consists of an acrylic-based primer and a polysiloxane-based coating applied on top. Hardcoat This includes such a protective coating. Such a coating should at least be applied to the surface of the transparent first material phase 1a used by the decorative element, which is later intended to be the outer surface in the installed position, in order to increase scratch resistance and weather stability.

[0069] The decorative element 2 is always clearly visible in its installed position due to the transparent first material phase 1a. The combination of the transparent material phase 1a, the opaque second material phase 1b behind it, and the decorative element 2 at the interface between the two material phases 1a and 1b creates a glass-like optical effect with a high degree of depth. The manufacturing process is suitable for industrial mass production, the decorative element 2 is protected from damage inside the add-on part 1, and the high stability requirements for vehicle components are met (windows made of rigid plastic, ECE R43 Annex 14, Class / M). These are significant advantages of the present invention.

[0070] Figur 2 Figure 1 shows an example of the structure of a suitable carrier film 5 with decorative element 2. The carrier film is made of PET and has a thickness of 20 µm. The decorative element 2 consists of three layers, namely, in increasing order of distance from the carrier film: a protective layer 2a, a decorative layer 2b, and an adhesive layer 2c. The decorative element 2 comes into contact with the first material phase 1a via the adhesive layer 2c. The adhesive layer 2c ensures strong adhesion between the decorative element 2 and the material phase 1a. The adhesive layer 2c is, for example, a layer of an acrylic-based adhesive with a thickness of 1.0 µm. The decorative layer 2b creates the actual visual effect of the decorative element 2. The decorative layer 2b is, for example, a layer with a thickness of 5.0 µm based on polyacrylate, which is colored by embedded or printed pigments or dyes in the form of the desired decoration.The protective layer 2a, for example, is an acrylic-based polymer layer with a thickness of 1.0 µm. The protective layer 2a protects the decorative layer from mechanical damage when the decorative element 2 is applied to the first material phase 1a.

[0071] A separating layer 6 is arranged between the carrier film 5 and the decorative element 2, which facilitates the detachment of the decorative element 2 from the carrier film 5. The separating layer has, for example, a thickness of 0.5 µm.

[0072] Figur 3 Figure 1 shows a cross-section through an attachment 1 according to the invention, including a decorative element 2. The attachment 1 consists of a transparent material phase 1a and an opaque material phase 1b. Such a structure occurs, for example, in the edge area of ​​window panes or across the entire surface of column covers. In the latter case, the transparent phase creates a glass-like effect with depth on the surface of the opaque phase, which is visually very appealing. The transparent material phase 1a consists, for example, of polycarbonate (PC) and has a thickness of 4 mm. The opaque material phase 1b consists, for example, of a PC / ABS mixture colored black by pigments such as carbon black and has a thickness of 2.5 mm. The transparent material phase 1a is intended to face the external environment when installed. The decorative element 2 is then clearly visible through the transparent material phase 1a in front of the opaque material phase 1b.

[0073] The surface of the first material phase 1a facing away from the decorative element, which forms the intended outer surface of the attachment 1, is provided with a protective coating 3, thus protecting it from mechanical damage. The protective coating also contains UV blockers, thereby protecting the decorative element 2 from fading due to UV radiation. The thickness of the protective coating 3 is, for example, approximately 20 µm.

[0074] Figur 4 Figure 1 shows a cross-section through an apparatus according to the invention for producing a polymeric vehicle add-on part 1 at various points in the process according to the invention. The apparatus comprises a first injection molding unit 11a for producing the transparent first material phase 1a and a second injection molding unit 11b for producing the opaque second material phase 1b. The two injection molding units 11a, 11b are arranged opposite each other. A rotary platen 13 is arranged between the injection molding units 11a, 11b, which carries a carrier mold 10 on one side. Another carrier mold is arranged on the opposite side of the rotary platen 13. The injection molding units 11a, 11b and the carrier molds 10 are spaced apart from each other in the initial stage ( Fig. 4(a) ).

[0075] The injection molding devices 11a and 11b are then brought close to the carrier molds 10 and brought into contact. A cavity is formed from the carrier mold 10 and a counter-mold of the first injection molding device 11a, the shape of which corresponds to the desired shape of the first material phase 1a. Subsequently, liquefied transparent polymer is injected into the cavity by the injection molding device 11a, where it hardens, thus creating the transparent material phase 1a. Fig. 4(b) ).

[0076] The injection molding units 11a, 11b are then removed from the carrier molds 10 and the indexing plate 13 is rotated by 180° so that the carrier mold 10 with the first material phase 1a faces the second injection molding unit 11b. A hot stamping agent 12 is then fed into the space between the first material phase 1a and the second injection molding unit 11b via a conveyor system. Fig. 4(c) The hot stamping agent 12 is used to apply a decorative element 2 to the first surface I of the first material phase 1a. The hot stamping agent 12 is then removed from the space. Alternatively, the hot stamping agent 12 can also be inserted into the space between the first injection molding unit 11a and the carrier mold 10 to apply the decorative element before the rotation of the indexable insert 13.

[0077] The injection molding units 11a and 11b are then brought close to the carrier molds 10 and brought into contact. A cavity is formed from the carrier mold 10 and a counter-mold of the second injection molding unit 11b, the shape of which corresponds to the desired shape of the second material phase 1b. Liquid opaque polymer is then injected into the cavity by the injection molding unit 11b, where it hardens, creating the opaque transparent material phase 1a on top of the transparent first material phase 1a. Fig. 4(b) ), wherein the decorative element 2 is arranged at the interface between the two material phases 1a, 1b. The second material phase 1b hardens and the injection molding devices 11a, 11b are then removed from the carrier molds 10. The finished attachment 1 can then be removed from the carrier mold 10.

[0078] The other carrier shape on the opposite side of the indexing plate 13 is assigned to the other injection molding unit. This allows various process steps to be carried out simultaneously during the production of two consecutive add-on parts: while the first material phase 1a of one add-on part a is being produced, the second material phase of the preceding add-on part is being injected at the same time. After rotation of the indexing plate 13, the second material phase 1b of the aforementioned add-on part is then injected simultaneously with the first material phase of the subsequent add-on part. This enables high cycle times to be achieved.

[0079] Figur 5 Figure 1 shows a top view of a further embodiment of the device according to the invention. Instead of a rotating plate 13, the support form is arranged here on a rotating cube 14, which can be rotated in 90° increments.

[0080] The device also comprises a first injection molding unit 11a and a second injection molding unit 11b, which are arranged opposite each other along a connecting axis. The hot stamping agent 12 is arranged perpendicular to this connecting axis. The carrier mold 10 is initially positioned facing the first injection molding unit 11a. After the first injection molding unit 11a approaches the carrier mold 10, the first material phase 1a is produced. A 90° rotation of the rotating cube 14 moves the carrier mold 10 into a second position, in which it faces the hot stamping agent 12. In this way, the first material phase 1a is provided with the decorative element 2. A further 90° rotation of the rotating cube 14 moves the carrier mold 10 into a third position, in which it faces the second injection molding unit 11b.After the second injection molding unit 11b approaches the carrier mold 10, the second material phase 1b is produced on the first material phase 1a. After a further rotation of 90°, the carrier mold 10 reaches a fourth position, in which the finished attachment 1 can be removed from the carrier mold.

[0081] Here too, the remaining three sides of the rotating cube 14 are equipped with further support forms that occupy the other positions, so that the device can work simultaneously on four different attachments.

[0082] Figur 6 Figure 1 shows a flowchart of an embodiment of the inventive method for manufacturing a polymeric vehicle add-on part with a decorative element. Reference symbol list:

[0083] (1)polymer vehicle attachment part (1a)first polymeric material phase of 1 (1b)second polymeric material phase of 1 (2) Decorative element (2a) Protective layer of 2 (2b) Decorative layer of 2 (2c) Adhesive layer of 2 (3) Protective coating (4) Stamp (5) Carrier film (6) Separating layer (10) Carrier mold (11a) First injection molding unit (11b) Second injection molding unit (12) Hot stamping medium (13) Turning platen (14) Rotating cube (I) first surface of 1a

Claims

1. Method for producing a polymeric vehicle add-on part (1) with a decorative element, wherein a. a first polymeric material phase (1a) is provided, b. a decorative element (2) is transferred from a carrier film (5) onto a first surface (I) of the first polymeric material phase (1a) by hot stamping using a punch (4), and c. a second polymeric material phase (1b) is applied on the first surface (I) of the first polymeric material phase (1a) such that the decorative element (2) is arranged between the first polymeric material phase (1a) and the second polymeric material phase (1b), wherein at least the first polymeric material phase (1a) or the second polymeric material phase (1b) is transparent and wherein providing the first material phase (1a) and applying the second material phase (1b) are done by injection molding.

2. Method according to claim 1, wherein in process step (b) - the carrier film (5) with the decorative element (2) is arranged such that the decorative element (2) faces the first polymeric material phase (1a), - the punch (4) acts on the surface of the carrier film (5) facing away from the decorative element (2) such that the decorative element (2) is pressed against the first surface (I), and - the carrier film (5) is detached, wherein the decorative element (2) remains on the first surface (I).

3. Method according to claim 1 or 2, wherein one of the two polymeric material phases (1a, 1b) is opaque.

4. Method according to claim 3, wherein the first polymeric material phase (1a) is transparent and the second polymeric material phase (1b) is opaque.

5. Method according to one of claims 1 through 4, wherein the first polymeric material phase (1a) and the second polymeric material phase (1b) are produced by injection molding and wherein the first polymeric material phase (1a) is moved between the process steps (a) and (c) by means of a turning plate (13) or a rotary cube (14).

6. Method according to one of claims 1 through 5, wherein the decorative element (2) comprises a protective layer (2a), a decorative layer (2b), and an adhesive layer (2c), which are arranged in this order on the carrier film (5), and wherein a release layer (6) is arranged between the carrier film (5) and the decorative element (2).

7. Method according to one of claims 1 through 6, wherein at least the surface of the transparent polymeric material phase (1a, 1b) facing away from the decorative element (2) is provided with a protective coating (3), which preferably contains thermally curing or UV-curing lacquers, particularly preferably polysiloxanes, polyacrylates, polymethacrylates, polyurethanes, or mixtures or copolymers thereof.

8. Method according to one of claims 1 through 7, wherein the punch (4) in process step (b) has a temperature of 120 °C to 250 °C, preferably of 140 °C to 200 °C.

9. Method according to one of claims 1 through 8, wherein the punch acts with a pressure of 15 g / cm2 to 50 kg / cm2 on the first surface (I), preferably of 20 kg / cm2 to 40 kg / cm2, particularly preferably of 25 kg / cm2 to 35 kg / cm2, with an exposure time of at least 1 s, preferably of 1 s to 10 s, particularly preferably of 2 s to 4 s.

10. Method according to one of claims 1 through 9, wherein the material phases (1a, 1b) contain polycarbonate, polymethyl methacrylate, styrene acrylonitrile, acrylonitrile styrene acrylester, polyethylene terephthalate, or copolymers or mixtures.

11. Apparatus for producing a polymeric vehicle add-on part (1) with a decorative element, at least comprising - a carrier mold (10), - a means for producing a first polymeric material phase (1a), - a hot stamping means (12) that is positionable relative to the first polymeric material phase (1a) such that a first surface (I) of the first material phase (1a) can be stamped with a decorative element (2), and - a means for producing a second polymeric material phase (1b) on the first surface (I) of the first material phase (1a), wherein the means for producing the first polymeric material phase (1a) is a first injection molding device (11a) and the means for producing the second polymeric material phase (1b) is a second injection molding device (11b), and wherein - the first injection molding device (11a) and the second injection molding device (11b) are arranged opposite one another, - the carrier mold (10) is movable by means of a turning plate (13) from a first position associated with the first injection molding device (11a) into a second position associated with the second injection molding device (11b), and - the hot stamping means (12) is movably mounted on a conveyor system and can be brought in between the first injection molding device (11a) and the carrier mold (10) or between the second injection molding device (11b) and the carrier mold (10), or - the first injection molding device (11a) and the second injection molding device (11b) are arranged opposite one another, - the hot stamping means (12) is arranged substantially perpendicular to the axis between the injection molding devices (11a, 11b), - the carrier mold (10) is movable by means of a rotary cube (14) from a first position associated with the first injection molding device (11a) through a second position associated with the hot stamping means (12) into a third position associated with the second injection molding device (11b).

12. Polymeric vehicle add-on part (1) with a decorative element, produced with the method according to one of claims 1 through 10, at least comprising a first polymeric material phase (1a), a second polymeric material phase (1b), and a decorative element (2) arranged between the two polymeric material phases (1a, 1b) that is applied by hot stamping on a first surface (I) of the first polymeric material phase (1a), wherein at least the first polymeric material phase (1a) or the second polymeric material phase (1b) is transparent and wherein the first polymeric material phase (1a) and the second polymeric material phase (1b) are produced by injection molding.

13. Use of a polymeric vehicle add-on part according to claim 12 in vehicles, wherein the transparent polymeric material phase (1a, 1b) faces outward, preferably as a radiator grill surround, pillar cover, sun visor, roof panel, vehicle window pane, light cover, mirror housing, frame member, trim strip, door sill, spoiler, fitting, or instrument panel.