Method for manufacturing a vehicle interior component and a vehicle interior component

Abstract

Method for manufacturing a vehicle interior component on the visible side of which a decorative print (3) is applied, wherein the vehicle interior component is manufactured as a plastic component in an injection molding process in which a plastic melt (2) is injected into a mold cavity of an injection mold (7) and subsequently cured, wherein, for the application of the decorative print (3), a printing ink layer forming the decorative print (3) is applied to a mold surface (21) of the mold cavity in a pad printing process or by IMC painting using stencil technology before the injection molding process, and wherein the applied printing ink layer is subsequently back-injected with the plastic melt (2) in the injection molding process to form a printed plastic component, characterized in that a clear coat (5) is applied to the visible side of the plastic component.and that, for the application of the clear coat (5), the plastic component remains in the mold cavity after its curing, and that the mold cavity is closed by forming a free mold gap (23) between the visible side of the plastic component and the mold surface (21), whereby the liquid starting component of the clear coat (5) is injected into the free mold gap (23).

Description

The invention relates to a method for producing a vehicle interior component according to the preamble of claim 1 and to a vehicle interior component according to claim 8.In the automotive sector, printed injection-molded components made of plastic are used as decorative elements. In an exemplary method for producing such a vehicle interior component, a plastic component is first produced in an injection molding process. After curing and demolding has taken place from the injection molding tool, a decorative print is applied to the visible side of the plastic component in a separate, subsequent printing process. The application of decorative printing can preferably be carried out in a pad printing process.Therefore, two separate manufacturing steps are required for manufacturing the vehicle interior component, namely injection molding and pad printing. The storage and transport costs of individual parts between the two production steps are correspondingly great.DE 10 2009 050 254 A1 discloses a method for applying a plagiate protector by means of pad printing, for example. In this case, a desired printed image which provides the protection against plagia is introduced into an injection mould. After the injection of the plastic material, the printed image is marked on the finished product.DE 10 2007 061 241 A1 discloses a method of the generic type for producing molded parts. DE 600 00 374 T2 discloses an ink container for pad printing machines. DE 60 2004 007 046 T2 discloses a method for transferring a membrane image to an article in a membrane image transfer printing process.The object of the invention is to provide a method for producing a vehicle interior component, in which the vehicle interior component can be produced in a simple manner from a manufacturing standpoint and with process times that are shortened in comparison with the prior art. A further object of the invention is to provide a vehicle interior component which can be produced in a simple manner from a manufacturing standpoint and with process times which are shortened in comparison with the prior art.The object is achieved by the subject matters having the features of claim 1 or claim 8. Preferred developments of the invention are disclosed in the dependent claims.According to the invention, the decorative print is no longer applied in a separate printing process to the already injection-molded plastic component, but rather an ink layer of the decorative print is applied to a mold molding surface delimiting the injection mold cavity already before the injection molding process is carried out. The application of the decorative print to the tool molding surface is preferably carried out in a pad printing process or alternatively by an IMC painting by means of stencil technology.Subsequently, in an injection molding process, a plastic melt is injected into the mold cavity to form the printed plastic component, whereby the plastic material behind the ink layer of the decorative print is injection molded.The printing ink layer is preferably applied to the tool forming surface in the pad printing process, namely with the aid of an elastically deformable printing pad which carries the printing ink layer. For transferring ink to the tool-forming surface, the printing pad is lowered and pressed onto the tool-forming surface of the injection-molding tool. This is done by adapting the pressure tamper to the tool shape surface contour. This results in ink transfer, whereupon the printed ink is removed from the mold surface again.After ink transfer to the mold surface, the mold cavity is closed to prepare the injection molding process. In the injection molding process, the plastic melt is injected into the mold cavity, specifically with the appearance-side applied decorative print forming the plastic component.In a downstream process step, a clearcoat material is applied to the cured plastic component. For a simple process-related clearcoat application, the plastic component still remains in the open mold cavity even after it has cured. The tool cavity is then closed, forming a free mold gap between the plastic component visible side and the tool molding surface. A clearcoat flooding process is then carried out, in which the liquid clearcoat starting component is injected into the free mold gap. The clearcoat material has the dual function of protecting the printing ink of the decorative print and also of acting depth as a design effect. Without such a clear lacquer layer, the selection of the printing / lacquer paints for decorative printing would be restricted, since these would then have to be scratch-resistant in any case. With regard to UV resistance, it would also not be possible to achieve special color shades (for example white) without a clearcoat coating, since these would yellow.An essential aspect of the invention consists in that all process steps, namely application of the decorative print, injection molding of the plastic component and application of the clear lacquer, are carried out in a common injection molding tool, as a result of which the required storage and transport outlay is greatly reduced.The above method is therefore not a direct color printing, but rather an indirect transfer printing, which takes place in the tool cavity and is not precisely on the finished plastic component. In addition, the component coating with clearcoat material takes place according to the invention in the shaping process and not, for example, separately therefrom following the shaping process.The ink is provided for the printed ink with a plate, on the surfaces of which depressions are formed. These reproduce a positive form of the decorative print. The printing ink is first rinsed over the cliché surface by means of a squeegee and then again removed from the cliché surface, printing ink remaining in the depressions. An ink uptake then takes place, in which the printed ink is pressed against the depressions of the printing plate with elastic deformation and the printing ink remains adhering to the printed ink, forming a negative form of the decorative print.As an alternative to the pad printing process, the ink layer of the decorative print can also be applied to the mold forming surface of the mold cavity as an IMC finish by means of stencil technology. In this case, a stencil simulating the negative form of the decorative print is first placed on the tool-forming surface of the injection-molding tool. Subsequently, an ink is applied in the IMC method within the injection mold, in which the ink is sprayed onto the mold-forming surfaces exposed by the recesses of the stencil with the aid of a spray head. If appropriate, after the spraying-on process, the applied printing ink can be cured under the action of heat. After the printing ink application has been completed, the stencil is removed from the injection mold again and the injection molding process is carried out.The invention and its advantageous embodiments and / or developments and its advantages are described below with reference to drawings.The following are shown: FIG. 1 is a schematic sectional view of a completed vehicle interior component; FIGS. 2 to 9 are views showing the steps of the method for manufacturing the vehicle interior member, respectively; and FIGS. 10 and 11 are views illustrating alternative process steps for applying the ink to the mold forming surface of the injection molding mold, respectively.FIG. 1 shows a sectional illustration of a vehicle interior component. Consequently, the component has a multilayer structure in which a decorative print 3 is applied to the visible side of a plastic carrier 1. The plastic carrier 1 is additionally covered over its entire surface on its visible side with a layer of clear lacquer 5. The clear lacquer layer 5 protects the visible side of the plastic carrier 1 from external mechanical influences. In addition, the layer of clear lacquer 5 achieves a depth effect as a design effect. By applying the layer of clear lacquer 5, the decorative print 3 can also be produced with printing or lacquer inks which are not scratch-resistant or are not UV-resistant per se.Next, referring to FIGS. 2 to 9, the method for manufacturing the vehicle interior structural member shown in FIG. 1 will be illustrated. The method is characterized in that both pad printing and clear lacquer flooding take place in a common injection mold 7 (or in its mold cavity).To prepare the pad print, the ink preparation shown in FIG. 2 is first carried out. For this purpose, a printing ink 9 for the decorative print 3 is washed by means of a doctor blade 11 over a surface of a printing plate 13. Subsequently, the printing ink 9 is again drawn off from the cliché surface. According to FIG. 2, depressions 15 are formed in the cliché surface, which reproduce the positive shape of the decorative print 3. After the printing ink 9 has been removed from the printing plate surface, printing ink 9 remains only in these depressions 15.The printing ink 9 remaining in the depressions 15 of the cliché surface can be accommodated by an elastically deformable printing pad 17. For such ink absorption, the printed ink 17 is pressed against the depressions 15 of the printing plate 13 with elastic deformation, whereby the printing ink 9 remains adhering to the printed ink 17 forming a negative form of the decorative print 3. The printed tamper 17 carrying the printing ink layer is then lowered according to FIGS. 4 and 5 and guided into an open tool cavity of an injection molding tool 7 (FIG. 7 ). Ink transfer then takes place, in which the pressure pad 17 is pressed against a tool-forming surface 21 of a first tool-forming half 7 adefining the tool cavity of the injection-molding tool 7 and is removed from the tool-forming surface 21 again. Thereby, the ink layer remains on the die forming surface 21 as shown in Fig. 6.Subsequently, according to FIG. 7, the tool cavity is closed by the two tool mold halves 7 aand 7 band a plastic melt 2 is injected into the tool cavity. The plastic melt 2 injection-molds the ink layer, namely, to form a printed plastic component. The printed plastic component formed in this way remains as a pre-injection molding in the tool cavity.After curing has taken place, the layer of clear lacquer 5 is applied to the visible side of the plastic component. The clear lacquer application takes place within the mold cavity of the injection mold 7. that is to say that according to the invention all process steps, namely the decorative print application, the injection molding process and the clear lacquer application take place in the injection mold 7.For the clear lacquer application, the tool cavity is closed again, namely forming a free mold gap 23 (FIG. 8 ) between the visible side of the plastic component and the tool mold surface 21, and the liquid starting component of the clear lacquer 5 is then injected into the free mold gap 23 by means of a mixing head 25. A PU lacquer is usually used as clear lacquer 5, that is to say the plastic component is flooded with clear polyurethane in FIG. 8.After the curing of the layer of clear lacquer 5, the finished plastic component is removed from the tool cavity in a demolding process.In the above exemplary embodiment, the application of the decorative print 3 takes place by means of a pad printing process. Alternatively, the decorative print 3 can also be applied by an IMC painting by means of stencil technology to the tool-forming surface 21 of the tool-forming half 7 a, as is indicated in FIGS. 10 and 11. For this purpose, according to FIG. 10, a stencil 27 is first inserted into the first mold half 7a to prepare the decorative print application. The stencil 27 has recesses 29 which form the negative form of the decorative print 3 to be produced. Subsequently, according to FIG. 11, the printing ink 9 is sprayed onto the sections exposed by the recesses 29 of the stencil 27 with the aid of a spray head 31.List of reference numbers:1 Plastic carrier 2 Plastic melt 3 Decorative print 5 Clear lacquer layer 7 Injection molding tool 7 a, 7 b Tool mold halves 9 Printing ink 11 Doctor blade 13 Cliché 15 Depression 17 Print pad 21 Mold surface 23 Mold gap 25 Mixing head 27 Stencil 29 Cutout 31 Spray head

Claims

Method for producing a vehicle interior component, on the visible side of which a decorative print (3) is applied, wherein the vehicle interior component is produced as a plastic component in an injection-molding process, in which a plastic melt (2) is injected into a mold cavity of an injection-molding tool (7) and then cured, wherein, for applying the decorative print (3), before carrying out the injection-molding process, an ink layer forming the decorative print (3) is applied to a mold surface (21) of the mold cavity in a pad printing process or by IMC painting by means of stencil technology, and wherein, subsequently, the applied ink layer is injection-molded with the plastic melt (2) in the injection-molding process, with the formation of a printed plastic component, characterized in that a clear lacquer (5) is applied to the visible side of the plastic component, and in that, for applying the clearcoat material (5), the plastics component remains in the mold cavity after curing thereof, and in that the mold cavity is closed with formation of a free mold gap (23) between the visible side of the plastics component and the mold molding surface (21), the liquid starting component of the clearcoat material (5) being injected into the free mold gap (23).Method according to claim 1, characterised in that the printing ink layer is applied to the mould surface (21) of the injection mould (7) by means of an elastically deformable printing pad (17) which carries the printing ink layer, and in that the printing pad (17) carrying the printing ink layer is pressed against the mould surface (21) and leaves the printing ink layer behind on the mould surface (21).Method according to Claim 2, characterized in that, after ink has been transferred to the tool moulding surface (21), the printing pad (17) is removed from the tool moulding surface (21) and the tool cavity is then closed, and in that the plastics melt (2) is then injected into the tool cavity, to be precise with the appearance-side decorative print (3) forming the plastics component.Method according to one of the preceding claims, characterized in that the plastic component coated with the clear lacquer (5) and printed with the decorative print (3) is removed from the mould cavity of the injection mould (7) in a demolding process after curing has taken place.Method according to one of the preceding claims, characterized in that the ink is provided for the printed ink (17) by means of a plate (13), on the surface of which depressions (15) are formed which reproduce the positive form of the decorative print (3), and in that the printing ink (9) is washed over the plate surface by means of a squeegee (11) and the printing ink (9) is subsequently drawn off again from the plate surface, the printing ink (9) being left behind in the depressions (15).Method according to Claim 5, characterized in that, for ink absorption, the printed ink pad (17) is pressed against the depressions (15) of the printing plate (13) with elastic deformation, and the printed ink layer remains adhering to the printed ink pad (17), forming a negative form of the decorative print (3).Method according to one of the preceding claims, characterized in that the process steps of applying the decorative print (3), injection moulding of the plastics component and application of the clearcoat (5) take place in a common injection moulding tool (7).Vehicle interior component produced in a method according to one of the preceding claims.

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