EP3723991B1 - Method for producing a component having at least two colour layers for a motor vehicle - Google Patents

Description

The present invention relates to a method for producing a component for a motor vehicle that has at least two color layers, the color layers being applied to a thin-walled support structure that at least partially defines the geometry of the component, the support structure consisting of a transparent or translucent polymer material and already before the Application of the color layers has a three-dimensional geometry with at least one spatial curvature, the support structure having an outside that is visible in the intended use and a rear side opposite the outside, the at least two color layers being applied to the back of the support structure and consequently through the support structure are at least partially visible or recognizable on the outside, the support structure having a first area or first areas in which on the outside only one e The first color layer or only parts of a first color layer can be seen, and the carrier structure also has a second area or second areas in which only the at least one further color layer or only parts of the at least one further color layer can be seen on the outside.

In the case of methods known from the prior art, the color layers are applied to the carrier structures before these carrier structures are brought into a three-dimensional form. Due to the subsequent reshaping or deformation of the carrier structure, however, it is not possible to clearly distinguish complex structures from one another through the layers of paint, since the reshaping or deformation process means that a complex structure (e.g. a color grid or parallel lines) can be manufactured precisely and, in particular, with repeat accuracy ) not possible is. In the case of support structures that are already three-dimensionally preformed, a masking template is therefore placed on the support structure in order to apply the first color layer, and this first color layer is then applied using a coating process (eg by spray painting). However, this method step is time-consuming, the positioning is imprecise and sometimes it does not reliably prevent a partial co-coating (so-called overspray) of the second area.

Other documents describing such or similar methods are in the documents JP 2010 274754A , WO 2013/083667 A2 , DE 20 2004 011153 U1 , WO 00/78520 A1 or U.S. 2009/169719 A1 disclosed.

The object of the invention is therefore to specify a method with the features described at the outset which, compared to the prior art, enables a component for a motor vehicle which has at least two layers of paint to be produced more quickly and reliably.

• Beschichten und gleichzeitiges Maskieren des ersten Bereichs oder der ersten Bereiche durch das Aufbringen der ersten Farbschicht auf der Rückseite der dreidimensional ausgebildeten Trägerstruktur mittels eines Tintenstrahldruckers, der zur Ausbildung der ersten Farbschicht eine flüssige oder pulverförmige Pigmenttinte oder eine flüssige oder pulverförmige Farbstofftinte auf die Rückseite der Trägerstruktur aufbringt,
• zeitgleiches oder nachfolgendes Aushärten und/oder Verfestigen der ersten Farbschicht, wobei das Aushärten und/oder Verfestigen teilweise, partiell oder vollständig erfolgt,
• Aufbringen der wenigstens einen weiteren Farbschicht zumindest auf den unmaskierten zweiten Bereich oder zumindest auf die unmaskierten zweiten Bereiche auf der Rückseite der Trägerstruktur.

This task is solved by the following procedure:
Process for producing a component for a motor vehicle that has at least two colored layers, the colored layers being applied to a thin-walled carrier structure that at least partially defines the geometry of the component, the carrier structure consisting of a transparent or translucent polymer material and having a three-dimensional shape even before the colored layers are applied formed geometry with at least one spatial curvature, wherein the carrier structure has an outside that is visible in the intended use and a rear side opposite the outside, the at least two color layers being applied to the rear side of the carrier structure and as a result being visible at least in sections through the carrier structure on the outside or are recognizable, the carrier structure having a first area or first areas in which on the outside only a first color layer or only parts of an e first layer of paint visible and wherein the carrier structure also has a second area or second areas in which only the at least one additional color layer or only parts of the at least one additional color layer can be seen on the outside, the method having the following sequence of steps:

• Coating and simultaneous masking of the first area or areas by applying the first color layer to the back of the three-dimensionally formed support structure using an inkjet printer which, to form the first color layer, applies a liquid or powdered pigment ink or a liquid or powdered dye ink to the back of the support structure raises
• Simultaneous or subsequent curing and/or solidification of the first paint layer, with the curing and/or solidification being partial, partial or complete,
• Application of the at least one further color layer at least to the unmasked second area or at least to the unmasked second areas on the back of the carrier structure.

The use of an inkjet printer, and thus the inkjet printing method, for the coating and simultaneous masking of the first area makes it possible, in comparison to prior art methods, to apply a very precise masking with a high spatial resolution to the three-dimensionally preformed carrier structure. During the coating and simultaneous masking of the first area or the first areas by applying the first color layer to the back of the three-dimensional carrier structure using an inkjet printer, to form the first color layer, a liquid or powdered pigment ink or a liquid or powdered dye ink on the back of the support structure, a print head of the inkjet printer can be moved by means of a manipulator (e.g. by means of a robot or a traversing unit) are moved over the back of the support structure. Alternatively or in combination, the support structure itself can be moved in relation to the print head by means of a manipulator. The distance of the inkjet printer or the print head of the inkjet printer from the surface of the back is preferably between 3 mm and 50 mm.

The back of the component's carrier structure is also called the "second-surface" or B-side. The support structure preferably has a three-dimensional geometry with at least two spatial curvatures.

The at least one further color layer can be applied to the second area or to the second areas on the rear side of the carrier structure by means of a coating process that differs from inkjet printing. Due to the fact that the first color layer applied by means of the inkjet printer already forms the masking on the carrier structure, a coating process can be selected for the at least one further color layer which has a greater area output (i.e. painted area per time) compared to inkjet printing. The combination of very precise inkjet printing with a coating process with a larger surface area makes it possible to implement a process with high precision and high speed at the same time.

The different coating method can include a spray painting method or a spray painting method or a brush coating or a dip coating or a roller coating or a plating method, in particular a PVD method or a CVD method, or an electroplating method.

The curing and/or hardening of the first color layer can be enabled and/or accelerated at least partially by supplying energy. In particular, UV-curing lacquers (ie lacquers that harden with ultraviolet light) can be used. In this case, at least one UV light source with the ink jet printer or coupled to the printhead of the inkjet printer. More preferably, in each direction of movement (in particular in the forward and backward direction) of the print head, there is a UV light source arranged in advance in the respective direction of movement on the inkjet printer or on the print head.

The first colored layer is preferably printed onto the back of the carrier structure with at least 100 dpi, preferably with at least 200 dpi, more preferably with at least 300 dpi.

Where dpi means "dots per inch".

The second area or the second areas can be defined by a local surface irregularity or by local surface irregularities on the outside and/or on the back of the carrier structure. This surface irregularity or these surface irregularities can then be additionally highlighted visually by means of the at least one further color layer.

Since the at least one further color layer must be applied exactly to the surface irregularity or irregularities and the printed image must not slip in relation to the surface irregularity or irregularities, the method according to the invention with its exact and precise masking of the second area or areas (in particularly suitable in this case of surface irregularity(s) due to the first layer of paint or masking applied by means of an inkjet printer.

The local surface irregularity can be formed by an indentation or a bead or a groove or lettering sunk into the material of the support structure or a satin finish or a grain or a raised pattern and/or a pattern sunk into the material of the support structure, or the local surface irregularities can be formed by Beading and/or grooves and/or lettering sunk into the material of the support structure and/or satin finishes and/or Graining and/or raised patterns and/or patterns embedded in the material of the support structure can be formed.

According to the invention, before or during the step of applying the first color layer, the respective tolerance deviations in the real dimensions of the carrier structure from the ideal dimensions of the carrier structure are determined, and the printed image stored for the ideal dimensions of the carrier structure is converted using these determined tolerance deviations and adapted to these real dimensions, so that the first Color layer is applied in a manner corresponding to the ideal dimensions of the support structure on the intended first area or on the intended first areas. The ideal dimensions of the carrier structure are preferably stored in a controller of the inkjet printer. More preferably, the print image for the ideal dimensions of the carrier structure is stored in or in a controller of the inkjet printer. The tolerance deviations in the real dimensions of the carrier structure that cannot be ruled out due to the production process (for example in a generative process or in injection molding or by thermoforming) can be compensated for in this way. In particular, in the event that a surface irregularity or surface irregularities described above must be masked, this ensures that the masking (i.e. the first layer of paint) is in the right place or in the right places (e.g. around the surface irregularity/s ) is applied by the inkjet printer.

The tolerance deviation can be determined using an optical measuring method, in particular by means of an optical image acquisition and image evaluation and/or by means of a triangulation method and/or by means of a confocal measuring method.

The first colored layer and/or the at least one further colored layer can be or can be built up by a large number of individual layers. That means the first The colored layer and/or the at least one further colored layer can in particular be made up of at least two or more individual layers.

The at least one further colored layer can be formed by a metal coating, in particular by a chrome coating. Consequently, the at least one further color layer does not necessarily mean a lacquer layer, but can also mean a coating by a metal.

The first color layer and/or the at least one further color layer can be applied in several adjacent strips. Consequently, the first colored layer and/or the at least one further colored layer does not necessarily have to be applied to the carrier structure in one pass, but can also be applied in several tracks. The adjacent webs can also overlap in their edge areas. The webs can preferably have a width of between 5 mm and 300 mm.

The component can be an exterior component of a motor vehicle, in particular a bumper cladding or a radiator grille cladding or a fender cladding or an A, B, C or D pillar cladding or a spoiler outer skin or a sill cladding or a door outer cladding or a door flap outer cladding.

The component can be part of an exterior component of a motor vehicle, in particular a part of a bumper trim or a radiator grille trim or a fender trim or an A, B, C or D pillar trim or a spoiler outer skin or a rocker panel or a door outer trim or a door flap outer trim form.

The carrier structure can be produced or has been produced by means of a generative process (eg 3D printing) or in an injection molding process or by thermoforming.

The transparent or translucent polymer material of the support structure can include in particular polycarbonate, polymethyl methacrylate, polystyrene (e.g. PS, ABS, ASA), thermoplastic polyester (e.g. PET, PBT) or a biopolymer (e.g. cellulose acetate, polyhydroxybutyrate, polylactic acid, polyhydroxyalkaonate).

Also part of the invention is a component that is produced using the method described above.

Fig. 1

den Verfahrensschritt des Beschichtens und gleichzeitigen Maskierens des ersten Bereichs durch das Aufbringen der ersten Farbschicht;

Fig. 2

Darstellung des Druckkopfes des Tintenstrahldruckers während des Beschichtens der Rückseite der Trägerstruktur;

Fig. 3

Querschnittsdarstellung der Trägerstruktur nach dem Aufbringen der ersten Farbschicht;

Fig. 4

Querschnittsdarstellung der Trägerstruktur nach dem Aufbringen der wenigstens einen weiteren Farbschicht;

Fig. 5

Aufbringung der erste Farbschicht in mehreren, nebeneinanderliegenden Bahnen.

The invention is explained below with reference to drawings that merely show exemplary embodiments. They show schematically:

1

the step of coating and simultaneously masking the first area by applying the first layer of paint;

2

Representation of the print head of the inkjet printer during the coating of the back of the support structure;

3

Cross-sectional representation of the carrier structure after the application of the first color layer;

4

Cross-sectional representation of the carrier structure after the application of the at least one further color layer;

figure 5

Application of the first layer of paint in several adjacent strips.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

In the Figures 1 to 5 describes a method for producing a component for a motor vehicle that has at least two color layers 1, 2. The color layers 1, 2 are applied to a thin-walled carrier structure 3 that at least partially defines the geometry of the component. The carrier structure 3 consists of a transparent or translucent polymer material and, even before the application of the colored layers 1, 2, has a three-dimensional geometry with at least one spatial curvature (cf. in particular Figures 1 to 4 ) on. The carrier structure 3 has an outer side A that is visible when used as intended and a rear side B that is opposite the outer side A (cf. in particular 3 and 4 ) on. At least that Two color layers 1, 2 are applied to the back B of the support structure 3 and are visible or recognizable through the support structure 3 on the outside A at least in sections as a result (due to the transparent or translucent polymer material of the support structure). The carrier structure 3 has a first region 6 or first regions 6, in which only a first color layer 1 or only parts of a first color layer 1 can be seen on the outside A (cf. in particular 3 ). The carrier structure 3 also has a second region 8 or second regions 8 in which only the at least one further color layer 2 or only parts of the at least one further color layer 2 can be seen on the outside A (cf. in particular 4 ).

• Beschichten und gleichzeitiges Maskieren des ersten Bereichs 6 oder der ersten Bereiche 6 durch das Aufbringen der ersten Farbschicht 1 auf der Rückseite B der dreidimensional ausgebildeten Trägerstruktur 3 mittels eines Tintenstrahldruckers 10, der zur Ausbildung der ersten Farbschicht 1 eine flüssige oder pulverförmige Pigmenttinte oder eine flüssige oder pulverförmige Farbstofftinte auf die Rückseite B der Trägerstruktur 3 aufbringt (vgl. Fig. 1 und Fig. 2);
• zeitgleiches oder nachfolgendes Aushärten und/oder Verfestigen der ersten Farbschicht 1, wobei das Aushärten und/oder Verfestigen teilweise, partiell oder vollständig erfolgt (vgl. insbesondere Fig. 3);
• Aufbringen der wenigstens einen weiteren Farbschicht 2 zumindest auf den unmaskierten zweiten Bereich 8 oder zumindest auf die unmaskierten zweiten Bereiche 8 auf der Rückseite B der Trägerstruktur (vgl. Fig. 4).

The procedure has the following order of steps:

• Coating and simultaneous masking of the first area 6 or the first areas 6 by applying the first color layer 1 to the rear side B of the three-dimensional carrier structure 3 using an inkjet printer 10, which, to form the first color layer 1, uses a liquid or powdered pigment ink or a liquid or applies powdered dye ink to the rear side B of the carrier structure 3 (cf. 1 and 2 );
• Simultaneous or subsequent curing and/or solidification of the first color layer 1, with the curing and/or solidification being partial, partial or complete (cf. in particular 3 );
• Application of the at least one further color layer 2 at least to the unmasked second area 8 or at least to the unmasked second areas 8 on the rear side B of the carrier structure (cf. 4 ).

As in 4 as can be seen, the at least one additional color layer 2 can also be additionally applied to the first color layer 1 , since this masks the first area 6 or the first areas 6 in front of the at least one additional color layer 2 .

During the coating and simultaneous masking of the first area 6 or the first areas 6 by applying the first color layer 1 to the rear side B of the three-dimensional carrier structure 3 by means of an inkjet printer 10, which, to form the first color layer 1, uses a liquid or powdered pigment ink or a applies liquid or powdered dye ink to the back B of the support structure 3, a print head of the inkjet printer 10 can be moved over the back B of the support structure 3 by means of a manipulator (eg by means of a robot or a traversing unit). will. Alternatively or in combination, the support structure 3 itself can be moved in relation to the print head by means of a manipulator.

The at least one further color layer 2 is applied to the second area 8 or to the second areas 8 on the rear side B of the carrier structure 3 by means of a coating process that differs from inkjet printing. The different coating method can include a spray painting method or a spray painting method or a brush coating or a dip coating or a roller coating or a plating method, in particular a PVD method or a CVD method, or an electroplating method.

The hardening and/or hardening is at least partially made possible and/or accelerated by the supply of energy. A UV curing material is preferably used for the pigment ink or for the dye ink.

The first color layer 1 is printed onto the rear side B of the carrier structure 3 with at least 100 dpi, preferably with at least 200 dpi, more preferably with at least 300 dpi.

The second area 8 is or the second areas 8 are defined by a local surface irregularity 12 or by local surface irregularities 12 on the outside A and/or on the back B of the carrier structure 3 (cf. 3 and 4 ). The local surface irregularity 12 is formed by an indentation or a bead or a groove or lettering sunk into the material of the support structure or a satin finish or a grain or a raised pattern and/or a pattern sunk into the material of the support structure 3, or the local surface irregularities 12 are formed by beads and/or grooves and/or lettering and/or satin finishes and/or graining and/or raised patterns and/or patterns embedded in the material of the support structure.

In a method step not shown in detail, before or during the step of applying the first color layer 1, the respective tolerance deviations in the real dimensions of the carrier structure 3 from the ideal dimensions of the carrier structure 3, preferably stored in a controller of the inkjet printer 10, are determined, and that for the ideal dimensions the carrier structure 3, preferably in the controller, stored print image converted based on these determined tolerance deviations and adapted to these real dimensions, so that the first color layer 1 in a manner corresponding to the ideal dimensions of the carrier structure 3 on the provided first area 6 or applied to the first areas 6 provided. The tolerance deviation can be determined using an optical measuring method, in particular by means of an optical image acquisition and image evaluation and/or by means of a triangulation method and/or by means of a confocal measuring method.

The first colored layer 1 and/or the at least one further colored layer 2 can be made up of a large number of individual layers (i.e. in particular of at least two individual layers).

The at least one further color layer 2 can be formed by a metal coating, in particular by a chrome coating.

The first color layer 1 is applied in several adjacent strips T (cf. figure 5 ).

The component can be an exterior component of a motor vehicle, in particular a bumper cladding or a radiator grille cladding or a fender cladding or an A, B, C or D pillar cladding or a spoiler outer skin or a sill cladding or a door outer cladding or a door flap outer cladding, or a Form part of the aforementioned components.

The carrier structure 3 can be produced or has been produced by means of a generative process (e.g. 3D printing) or in an injection molding process or by thermoforming.

Claims (12)

1. A method for producing a component comprising at least two colour layers (1, 2) for a motor vehicle,

   wherein the colour layers (1, 2) are applied to a thin-walled carrier structure (3) that at least partially defines the geometry of the component,

   wherein the carrier structure (3) consists of a transparent or translucent polymer material and already has a three-dimensional geometry with at least one curved space before the colour layers (1, 2) are applied,

   wherein the carrier structure (3) has an outer side (A), which is visible when the component is used as intended, and a rear side (B) opposite the outer side (A),

   wherein the at least two colour layers (1, 2) are applied to the rear side (B) of the carrier structure (3) and as a result are visible or discernible at least in some portions from the outer side (A) through the carrier structure,

   wherein the carrier structure (3) comprises a first region (6) or first regions (6), in which only a first colour layer (1) or only parts of a first colour layer (1) are identifiable from the outer side (A), and

   wherein the carrier structure (3) further comprises a second region (8) or second regions (8) in which only the at least one further colour layer (2) or only parts of the at least one further colour layer (2) are identifiable from the outer side (A),

   wherein

   the method comprises the following sequence of steps:

   - coating and simultaneously masking the first region (6) or the first regions (6) by applying the first colour layer (1) to the rear side (B) of the three-dimensionally-configured carrier structure (3) by means of an inkjet printer (10) that applies a liquid or powdery pigment ink or a liquid or powdery dye ink to the rear side (B) of the carrier structure (3) in order to form the first colour layer (1),

   - simultaneously or subsequently curing and/or solidifying the first colour layer (1), wherein the curing and/or solidification is carried out to some extent, partially or completely;

   - applying the at least one further colour layer (2) to the rear side (B) of the carrier structure at least in the unmasked second region (8) or at least in the unmasked second regions (8),

   characterised in that

   before or during the step of applying the first colour layer (1), the respective tolerance deviations of the actual measurements of the carrier structure (3) from the ideal measurements of the carrier structure (2), preferably stored in a controller of the inkjet printer (10), are determined and the print image stored for the actual dimensions of the carrier structure (3), preferably in the controller, is recalculated on the basis of these determined tolerance deviations and adapted to these actual dimensions, so that the first colour layer (1) is applied to the intended first region (6) or to the intended first regions (6) in a manner corresponding to the ideal dimensions of the carrier structure (3).
2. The method according to claim 1, characterised in that the tolerance deviation is determined on the basis of an optical measurement method, in particular by means of an optical image acquisition and image evaluation and/or by means of a triangulation process and/or by means of a confocal measurement process.
3. The method according to claim 1 or 2, characterised in that the at least one further colour layer (2) is applied to the rear side (B) of the carrier structure (3) in the second region (8) or in the second regions (8) by means of a coating method that differs from inkjet printing.
4. The method according to claim 3, characterised in that the different coating method comprises a spray painting method or an aerosol painting method or a brush painting or a dip painting or a roller painting or a plating method, in particular a PVD method or a CVD method, or a galvanic deposition method.
5. The method according to one of the preceding claims, characterised in that the hardening and/or solidification is made possible and/or accelerated at least in part by an energy input.
6. The method according to one of the preceding claims, characterised in that the first colour layer (1) is printed with at least 100 dpi, preferably with at least 200 dpi, more preferably with at least 300 dpi onto the rear side (B) of the carrier structure (3).
7. The method according to one of the preceding claims, characterised in that the second region (8) or the second regions (8) is or are predefined by a local surface irregularity (12) or by local surface irregularities (12) on the outer side (A) and/or on the rear side (B) of the carrier structure (3).
8. The method according to claim 7, characterised in that the local surface irregularity (12) is formed by an indentation or a bead or a groove or a lettering recessed in the material of the carrier structure or a satin finish or a graining or a raised pattern and/or a pattern recessed in the material of the carrier structure, or the local surface irregularities (12) are formed by beads and/or grooves and/or a lettering recessed in the material of the carrier structure and/or satin finishes and/or grainings and/or raised patterns and/or patterns recessed in the material of the carrier structure.
9. The method according to one of the preceding claims, characterised in that the first colour layer (1) and/or the at least one further colour layer (2) are per se built up by multiple individual layers.
10. The method according to one of the preceding claims, characterised in that the at least one further colour layer (2) is formed by a metal coating, in particular by a chromium coating.
11. The method according to one of the preceding claims, characterised in that the first colour layer (1) and/or the at least one further colour layer (2) is applied in a plurality of adjacent tracks (T).
12. The method according to one of the preceding claims, characterised in that the component is an exterior component of a motor vehicle, in particular a bumper covering or a radiator grille covering or a mudguard covering or an A-, B-, C- or D-pillar covering or a spoiler skin or a sill covering or an outer door covering or an outer door panel covering, or forms a part of the aforementioned components.

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