Plastic Cover Comprising a Coating Layer

Abstract

A plastics cover for a motor vehicle includes a visible side, an inner side, and a carrier side. The carrier layer is composed of a transparent polymer material, which has a continuous and constant basic wall thickness and at least one of an arrow-shaped, tetrahedral, pyramidal, conical, or cuboidal recess at which at least one wall thickness variation is formed on the inner side of the carrier layer. The finishing layer which is arranged on a visible surface of the carrier layer. The finishing layer comprises a transparent polymer material.

Claims

1.-11. (canceled)

12. A plastics cover for a motor vehicle, comprising: a visible side; an inner side; a carrier layer composed of a transparent polymer material, which has a continuous and constant basic wall thickness and at least one of an arrow-shaped, tetrahedral, pyramidal, conical, or cuboidal recess at which at least one wall thickness variation is formed on the inner side of the carrier layer; and a finishing layer which is arranged on a visible surface of the carrier layer, wherein the finishing layer comprises a transparent polymer material.

13. The plastics cover according to claim 12, wherein the finishing layer, on the inner side thereof, follows the shape of a defect site in the visible surface of the carrier layer but has a continuous visible side.

14. The plastics cover according to claim 13, wherein the transparent polymer material of the finishing layer comprises a polyurethane.

15. The plastics cover according to claim 14, wherein the finishing layer has a wall thickness of between 0.2 and 0.5 mm.

16. The plastics cover according to claim 15, wherein the carrier layer is doubly curved.

17. The plastics cover according to claim 16, further comprising: a masking layer and/or an inner top layer which are/is arranged on the inner side of the carrier layer.

18. A method for producing a plastics cover according to claim 17, comprising: injection-molding a carrier layer composed of a first transparent polymer material; and injection-molding or flow-coating a finishing layer composed of a second transparent polymer material directly onto a visible side of the carrier layer.

19. The method according to claim 18, wherein the carrier layer is at least partially cured before the finishing layer is molded on.

20. The method according to claim 19, wherein the carrier layer is molded in a first cavity, and the finishing layer is molded in a second cavity, in particular of an injection-molding installation.

21. The method according to claim 20, wherein, after the carrier layer has been molded, a mold wall of an injection-molding cavity, at which wall the visible side of the carrier layer is formed, is set back, in particular by the desired wall thickness of the finishing layer, and the second polymer material is subsequently injected.

22. The method according to claim 18, wherein the carrier layer is produced in a separate injection-molding tool on an injection-molding machine and is subsequently inserted in a further tool and overmolded with a finishing layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 schematically shows a detail of a cross section of a plastics cover;

[0036] FIG. 2 schematically shows a cross section of a plastics cover;

[0037] FIG. 3 schematically shows various steps of a method for producing a plastics cover according to FIG. 2; and

[0038] FIG. 4 shows an oblique view of a plastics cover.

DETAILED DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 illustrates a cross section of a plastics cover 1, such that a visible side 2 is illustrated on the left and an inner side 4 of the plastics cover 1 is illustrated on the right. The plastics cover 1 has a carrier layer 6 composed of a transparent, thermoplastic polycarbonate (PC).

[0040] FIG. 1 shows only the surroundings of a recess 11 in the carrier layer 6, said recess extending from an inner surface 12 of the carrier layer 6 into the layer body thereof. Beyond the recess 11, the carrier layer 6 has a basic wall thickness 14*. The recess 11 itself projects into the layer body insofar as the latter has a minimum wall thickness 14 in the region of the recess. At the recess 11, a wall thickness variation 15 is thus produced from the difference between the basic wall thickness 14* and the minimum wall thickness 14. At the wall thickness variation 15, the wall thickness development is not continuous but rather is abrupt.

[0041] As a result of the recess 11, the carrier layer 6 may have, on the visible side 2, a schematically illustrated, minimum unevenness of a visible surface 22 (collectively referred to as defect site 23).

[0042] On the visible side 2 of the carrier layer 6, there is arranged a transparent finishing layer 20 which not only protects a visible surface 22 of the carrier layer against wear but also compensates for the defect sites 23. In the exemplary embodiment, the finishing layer 20 is formed of a transparent polyurethane material which compensates for any existing defect site 23 and which, for its part, has a continuous, in particular a flat and/or smooth, visible surface 21.

[0043] Typically, the finishing layer 20 is 0.3 to 0.5 mm thick, particularly if the basic wall thickness 14* of the carrier layer 6 is and/or ranges between 3 and 6 mm, which represents a typical basic wall thickness range for the carrier layer 6 of exterior covers in the case of motor vehicles.

[0044] In spite of the simplified schematic illustration of FIG. 1, the carrier layer 6, in its entirety or in partial regions, can be of singly or doubly curved configuration. The carrier layer can also have a constant or a continuous basic wall thickness 14*.

[0045] FIG. 2 illustrates a cross section of a plastics cover 100, such that a visible side 2 is illustrated on the left and an inner side 4 of the plastics cover 100 is illustrated on the right.

[0046] The plastics cover 100 has a carrier layer 6 composed of a transparent, thermoplastic polycarbonate (PC).

[0047] On the visible side 2 of the carrier layer 6, there is arranged a transparent finishing layer 20 which protects a visible surface 22 of the carrier layer against wear. In the exemplary embodiment, the finishing layer 20 is formed of a transparent polyurethane material which compensates for any existing defect sites 23 and which, for its part, has a continuous, in particular a flat and/or smooth, visible surface 21.

[0048] On the inner side 4 thereof, the carrier layer 6 of the plastics cover 100 has a masking region 8 and a plurality of mutually spaced-apart accented regions 10. The masking region 8 and the accented regions 10 together form an inner surface 12 of the carrier layer 6 (or at least a part thereof).

[0049] In spite of the simplified schematic illustration of FIG. 2, the carrier layer 6, in its entirety or in partial regions, can be of singly or doubly curved configuration. The carrier layer can also have a constant or a continuous basic wall thickness 14*.

[0050] The masking region 8 is arranged on that partial region of the inner surface 12 which has the basic wall thickness 14*. Each of the accented regions 10 is arranged on a partial region of the inner surface 12, in which partial region a wall thickness 14 is configured to be smaller than the basic wall thickness 14* at said point of the carrier layer 6, in particular with a non-continuous wall thickness variation 15.

[0051] In the exemplary embodiment illustrated, each accented region 10 has a tetrahedral recess 11 which proceeds from the inner surface 12 of the carrier layer 6. As a result of the tetrahedral recesses 11, the carrier layer 6 may have, on the visible side 2, schematically illustrated defect sites 23 of a visible surface 22.

[0052] On that part of the inner surface 12 on which the masking region 8 is configured, the plastics cover 100 has a masking layer 16 which is formed by means of a film or by means of a printing ink which is applied directly onto the inner surface 12. Substantially no masking layer is configured in the accented regions 10.

[0053] An opaque inner top layer 18 is arranged on the entire inner surface 12—that is to say on the masking region 8 and on the accented regions 10—on the inner side, said top layer being applied by means of a PVD process in the exemplary embodiment.

[0054] The regions 8 and 10 are not absolutely necessary for compensating for the defect site 23 and thus are only shown as a typical but optional design variant in the present exemplary embodiment.

[0055] On the visible side 2 of the carrier layer 6, there is arranged a transparent finishing layer 20 which protects a visible surface 22 of the carrier layer against wear and environmental influences. In the exemplary embodiment, the finishing layer 20 is formed of a transparent polyurethane material which compensates for any existing defect sites 23 and which, for its part, has a smooth visible surface 21.

[0056] In the exemplary embodiment, all of the aforementioned layers—the finishing layer 20, the carrier layer 6, the masking layer 16 and the inner top layer 18—are configured to be free of metal or, if a metallic material is used, to be sufficiently thin that they have a suitably low electrical conductivity for a sensor-transparent design of the plastics cover 100. A sensor-transparent design is understood to mean in particular a low radar absorption, and also a low radar reflection, in the frequency band of 76-77 GHz, such that, for example, a radar sensor can be arranged behind the plastics cover and can monitor a sensor field in front of the plastics cover during operation.

[0057] FIGS. 3a-d schematically illustrate various steps of a method for producing a plastics cover 100 according to FIG. 2.

[0058] FIG. 3a shows a greatly simplified depiction of an injection-molding installation 50, which is represented in the illustration by a closed first mold 51. The first mold 51 represents a suitably designed negative of the desired shape of the carrier layer 6. During performance of the method, a PC material is injected into the mold and at least partially cured.

[0059] FIG. 3b illustrates a second mold 52 in the closed state, into which the sufficiently cured carrier layer 6, after having been molded itself, is inserted. In the second mold 52, for performance of the method, an inviscid PUR material is molded onto the visible surface 22 of the carrier layer 6. In this way, the defect sites 23 can be compensated.

[0060] The manufacturing steps described in FIG. 3c and FIG. 3b are necessary merely for typical plastics covers with depth effect but are not absolutely necessary for compensating for the defect site.

[0061] FIG. 3c illustrates a print head 30 which prints the masking layer 16 in the masking region 8, with the accented regions 10 being left out. The print head 30 is configured to be moved, along a schematically illustrated movement apparatus 31, along the inner surface 12 and in particular in the masking region 8 in a three-dimensional manner. As an alternative, the masking can also be applied by means of a film or a lacquer.

[0062] In FIG. 3d, the carrier layer 6 in the masking region 8 has been completely printed or completely covered with the film. On the inner surface 12, which has been printed in this way, of the carrier layer 6, the inner top layer 18 is applied by means of a PVD apparatus 40, the dissolved particles from the PVD apparatus 40 being deposited on said top layer, specifically both in the masking region 8 and in the accented regions 10.

[0063] FIG. 4 illustrates a front plastics cover 200 for a motor vehicle in an oblique view from the visible side 2, such that the observer is looking at the visible surface 21 of the finishing layer 20. In addition to the frame, the masking region 8 which has been printed with the masking layer 16 is illustrated, visible in black, said masking region appearing dark as a result of the printing ink.

[0064] Contrasting therewith are the recesses 11, in the respective accented region 10 of which no printing ink has been applied, such that the lighter inner top layer 18 reflects the incident light through the transparent carrier layer 6 around the transparent finishing layer 20. It is thus possible to obtain the visible three-dimensional more visual effect which, owing to the PUR finishing layer 20 molded onto the carrier layer, can appear to the observer to have no, or significantly fainter, visible defect sites 23.

[0065] Typically, the finishing layer 20 is 0.2 to 1.5 mm thick, particularly if the basic wall thickness 14* of the carrier layer 6 ranges between 3 and 6 mm. In relation thereto, the printed masking layer 16 and the (PVD-)sputtered inner top layer 18 have negligible layer thicknesses in the micrometer and/or nanometer range.

LIST OF REFERENCE DESIGNATIONS

[0066] 1 Plastics cover [0067] 2 Visible side [0068] 4 Inner side [0069] 6 Carrier layer [0070] 8 Masking region [0071] 10 Accented region [0072] 11 Recess [0073] 12 Inner surface [0074] 14 Wall thickness [0075] 14* Basic wall thickness [0076] 15 Wall thickness variation [0077] 16 Masking layer [0078] 18 Inner top layer [0079] 20 Finishing layer [0080] 21 Visible surface of the finishing layer [0081] 22 Visible surface of the carrier layer [0082] 23 Defect site [0083] 30 Printing apparatus [0084] 31 Movement apparatus [0085] 40 PVD apparatus [0086] 50 Injection-molding installation [0087] 51 First mold [0088] 52 Second mold [0089] 100 Plastics cover [0090] 200 Front plastics cover of a motor vehicle