Cover element and method for manufacturing a cover element

Abstract

Cover element, in particular for the external cladding of a motor vehicle, comprising: - an injection-molded main body (1) made of a transparent or translucent polymer material (2) and, - a carrier film (3) with at least one heating conductor (4) applied to the carrier film (3) or with at least one heating layer applied to the carrier film (3), which can be heated by an electric current or by radiation, wherein the carrier film (3) has a film thickness T and at least one side edge (5), wherein the carrier film (3) is connected to the main body (1) at least in the area of ​​the side edge (5) by means of an overmolding of the carrier film (3) or by means of an overmolding of the carrier film (3) with the polymer material (2) of the main body (1), characterized by the fact that in the area of ​​at least one side edge (5) the film thickness T decreases to a thinner film thickness t at the side edge (5), so that the visual detectability of the transition (U) from the carrier film (3) to the polymer material (2) of the main body (1) adjacent to the carrier film (3) is minimized.

Description

[0001] The present invention relates to a covering element, in particular for the outer cladding of a motor vehicle, comprising an injection-molded main body made of a transparent or translucent polymer material and a carrier film with at least one heating conductor applied to the carrier film or with at least one heating layer applied to the carrier film, which can be heated by current or by radiation, wherein the carrier film has a film thickness T and at least one side edge, wherein the carrier film is connected to the main body at least in the region of the side edge by back-injection of the carrier film or by over-injection of the carrier film with the polymer material of the main body.

[0002] Examples of generic cover elements can be found in documents DE 10 2012 105 564 A1, DE 10 2018 219 294 A1, EP 3 252 494 A1, DE 10 2014 214 329 A1, DE 10 2014 002 438 A1, and DE 10 2011 122 345 A1. With all of these cover elements known from the prior art, there is a risk that, due to the transparent or translucent polymer material of the injection-molded main body, the transition from the carrier film to the polymer material of the main body adjacent to the carrier film is clearly visible, leading to a significant impairment of the overall aesthetic impression of the cover element. Since such cover elements are generally used in the visible area, in particular in motor vehicles, in cover elements of the prior art this transition from the carrier film to the polymer material of the main body adjacent to the carrier film is covered by an additional laminated panel or an adjacent component.This has the disadvantage that additional components are required and the design freedom in the design of the cover element is also limited.

[0003] The object of the present invention is therefore to provide a cover element in which the transition from the carrier film to the polymer material of the main body adjacent to the carrier film is not visible and, as a result, this transition can be located in the visible area of ​​the cover element.

[0004] This object is achieved according to the invention by a covering element, in particular for the external cladding of a motor vehicle, comprising: - an injection-molded main body made of a transparent or translucent polymer material and, - a carrier film with at least one heating conductor applied to the carrier film or with at least one heating layer applied to the carrier film, which can be heated by current supply or by irradiation, wherein the carrier film has a film thickness T and at least one side edge, wherein the carrier film is connected to the main body at least in the region of the side edge by back-injection of the carrier film or by over-injection of the carrier film with the polymer material of the main body, wherein in the region of the at least one side edge the film thickness T decreases to a thinner film thickness t at the side edge, so that the visual recognizability of the transition from the carrier film to the polymer material of the main body adjacent to the carrier film is minimized.Due to the film thickness becoming thinner towards the side edge, there is no or at least significantly less turbulence of the injected polymer material of the main body during back-injection or over-injection at at least one side edge of the carrier film. This turbulence leads to gas pockets, voids, or sink marks, so avoiding them contributes significantly to minimizing the visual detectability of the transition from the carrier film to the polymer material of the main body adjacent to the carrier film.In addition, the thickness of the polymer material below or above the area of ​​the side edge of the carrier film increases as the thickness of the carrier film decreases in this area, so that there is a continuous phase transition between the material, in particular a polymer material, of the carrier film and the polymer material of the main body and by avoiding an abrupt phase transition the visual recognizability is also reduced.

[0005] In the case of overmolding, the film thickness T preferably decreases from the side of the carrier film oriented toward the intended visible side of the main body to the thinner film thickness t. In the case of backmolding, the film thickness T preferably decreases from the side of the carrier film oriented away from the intended visible side of the main body to the thinner film thickness t. Depending on where the future visible side of the cover element is located during its intended use or installation situation, a further improved result can be achieved.

[0006] The thinner film thickness t can be at least 40%, preferably at least 60%, particularly preferably at least 80% thinner than the film thickness T. The thinner film thickness t can have a value of approximately or equal to 0. Typical values ​​for the film thickness T are in the range from 150 µm to 800 µm, preferably in the range from 200 µm to 500 µm, particularly preferably in the range from 250 µm to 400 µm. The typical wall thickness of the injection-molded main body is in the range from 1.5 mm to 3.5 mm, preferably in the range from 1.8 mm to 2.7 mm.

[0007] The transparent polymer material may comprise or consist of a polycarbonate, polymethyl methacrylate, polyamide, polyolefin, polypropylene, polyethylene or acrylonitrile-butadiene-styrene copolymer.

[0008] Preferably, the cover element forms or is used for a cover for a sensor or a cover for a radar unit or a cover for a camera or a cover for a lidar unit or a cover for a lighting unit.

[0009] The carrier film can be beveled in the area of ​​the side edge at an angle α of 20° to 75°, preferably at an angle α of 30° to 60°. This reduces the film thickness T to the thinner film thickness t at the side edge.

[0010] In the area of ​​the side edge, in a cross-section of the carrier film, the film thickness T can decrease in an elliptical curve from the film thickness T to the thinner film thickness t at the side edge.

[0011] The carrier film preferably consists of a material, preferably also of a polymer material, which is compatible, of the same type or identical to the polymer material of the main body.

[0012] The invention further comprises a method for producing a cover element, in particular for the outer cladding of a motor vehicle, wherein the cover element has an injection-molded main body made of a transparent polymer material and a carrier film with at least one heating conductor applied to the carrier film.

[0013] The procedure includes the following steps: - Providing a carrier film with a heating conductor applied to the carrier film or with at least one heating layer applied to the carrier film, which can be heated by current or by radiation, wherein the carrier film has a film thickness T and at least one side edge, - arranging the carrier film in a cavity of an injection molding tool formed between at least two tool halves and defining a main body, - Injecting a plasticized polymer material into the cavity of the injection mold to form the main body, - connecting the carrier film to the main body at least in the area of ​​the side edge by back-injecting the carrier film or by over-injecting the carrier film with the polymer material of the main body, - cooling and demoulding the cover element thus formed, wherein in the region of at least one side edge the film thickness T decreases to a thinner film thickness t at the side edge, so that the visual recognizability of the transition from the carrier film to the polymer material of the main body adjacent to the carrier film is minimised.

[0014] Preferably, at least one of the mold halves of the injection molding tool has an additional heating system in the region of the side edge of the carrier film arranged in the cavity, which heating system enables a locally elevated temperature of the at least one mold half in the region of the side edge of the carrier film compared to the remaining at least one mold half. Due to the locally elevated temperature of the at least one mold half in the region of the side edge of the carrier film, the viscosity of the plasticized polymer material (i.e., the polymer melt) of the main body in the region of the side edge of the carrier film is reduced and / or the plasticized polymer material in the region of the side edge of the carrier film is kept in the plasticized state for longer.This also reduces the problem of turbulence of the plasticized polymer material in the area of ​​the side edge of the carrier film, described above, thus further minimizing the visual visibility of the transition from the carrier film to the polymer material of the main body adjacent to the carrier film. Heating is preferably carried out variothermally.

[0015] The at least two mold halves may not be completely closed during the injection of the plasticized polymer material, and the mold halves can only be closed during the solidification process of the polymer material. Alternatively, or in combination, the mold halves can be opened due to the internal pressure that increases during the injection of the polymer material, and they can only be closed again during the solidification process of the polymer material. These process steps, known as injection-compression molding, allow the visual perceptibility of the transition from the carrier film to the polymer material of the main body adjacent to the carrier film to be further minimized.

[0016] The invention is explained in more detail using figures which merely represent exemplary embodiments.

[0017] They show: Fig. 1 and Fig. 2: Examples of a cover element with different geometries of the carrier film; Fig. 3 and Fig. 4: Partial cross-sectional views of examples of a cover element; Fig. 5 to 8: Sequences of individual sub-steps of the method according to the invention; Fig. 9 to 10: further examples of a cover element in the form of a brand emblem, each with different geometries of the carrier film.

[0018] Identical or functionally equivalent elements are provided with the same reference symbols.

[0019] The Fig. 1 and the Fig. 2 each show a covering element, in particular for the outer cladding of a motor vehicle, comprising an injection-molded main body 1 made of a transparent or translucent polymer material 2 and a carrier film 3 with at least one heating conductor 4 applied to the carrier film 3 or with at least one heating layer applied to the carrier film 3, which can be heated by current or by radiation, wherein the carrier film 3 has a film thickness T and at least one side edge 5 (cf. also Fig. 3 and Fig. 4). The carrier film 3 is connected to the main body 1 at least in the region of the side edge 5 by back-injection of the carrier film 3 or by over-injection of the carrier film 3 with the polymer material 2 of the main body 1. In the region of at least one side edge 5, the film thickness T decreases to a thinner film thickness t at the side edge 5, so that the visual recognizability of the transition U from the carrier film 3 to the polymer material 2 of the main body 1 adjacent to the carrier film 3 is minimized. Fig. 3 and in the Fig. 4, the film thickness decreasing in the area of ​​the side edge 5 from the film thickness T to the thinner film thickness t at the side edge 5 is explained in cross-sectional views. Fig. Figure 3 shows the case of overmolding. In this case, the film thickness T decreases from the side A of the carrier film 3 oriented towards a designated visible side S of the main body 1, starting at the thinner film thickness t. The thinner film thickness t takes on a value of or close to 0. In the case of backmolding (shown in Fig. 4) The film thickness T decreases from the side B of the carrier film 3 oriented away from the intended visible side S of the main body 1 to the thinner film thickness t. The thinner film thickness t is at least 40%, preferably at least 60%, particularly preferably at least 80% thinner than the film thickness T.

[0020] In the Fig. 3 and Fig. In the examples shown in Figure 4, the carrier film 3 is beveled in the region of the side edge 5 at an angle α of 20° to 75°, preferably at an angle α of 30° to 60°, and as a result, the film thickness T decreases to the thinner film thickness t at the side edge 5. Alternatively or in combination, in the region of the side edge 5, in a cross-section of the carrier film 3, the film thickness T decreases in an elliptically shaped curve from the film thickness T to the thinner film thickness t at the side edge 5.

[0021] For all cover elements described above, the transparent polymer material 2 may comprise a polycarbonate, polymethyl methacrylate, polyamide, polyolefin, polypropylene, polyethylene or acrylonitrile-butadiene-styrene copolymer or consist of one of these materials.

[0022] For the cover elements described above, it may also apply that the cover element forms or is used as a cover for a sensor or a cover for a radar unit or a cover for a camera or a cover for a lidar unit or a cover for a lighting unit.

[0023] In addition, for all cover elements described above, the carrier film 3 may be made of a material that is compatible, of the same type, or identical to the polymer material 2 of the main body 1.

[0024] Based on the Fig. 5 to Fig. 8, the method for producing a cover element, in particular for the outer lining of a motor vehicle, is described below. The cover element comprises an injection-molded main body 1 made of a transparent polymer material 2 and a carrier film 3 with at least one heating conductor 4 applied to the carrier film 3 or with at least one heating layer applied to the carrier film 3. The method comprises the following steps:

[0025] In the Fig. 5 shows the provision of a carrier film 3 with a heating conductor 4 applied to the carrier film 3 or with at least one heating layer applied to the carrier film 3, which can be heated by current supply or by radiation, wherein the carrier film 3 has a film thickness T and at least one side edge 5.

[0026] In Fig. 6 shows the step of arranging the carrier film 3 in a cavity 12 of an injection molding tool 13 formed between at least two tool halves 10, 11 and defining a main body 1.

[0027] In Fig. 7, the injection of a plasticized polymer material 2 into the cavity 12 of the injection molding tool 13 takes place in order to form the main body 1, as well as the step of connecting the carrier film 3 to the main body 1 at least in the region of the side edge 5 by back-injection of the carrier film 3 or by over-injection of the carrier film 3 with the polymer material 2 of the main body 1.

[0028] Finally, in Fig. 8 shows the cooling and demoulding of the cover element thus formed.

[0029] For all method steps described above, the film thickness T decreases in the region of at least one side edge 5 to a thinner film thickness t at the side edge 5, so that the visual recognizability of the transition U from the carrier film 3 to the polymer material 2 of the main body 1 adjacent to the carrier film 3 is minimized.

[0030] In the method steps described above, one of the tool halves 10 of the injection molding tool 13 has an additional heating 14 in the region of the side edge 5 of the carrier film 3 arranged in the cavity 12, which heating enables a locally increased temperature of the tool half 10 in the region of the side edge 5 of the carrier film 3 compared to the remaining tool half 10.

[0031] In variations of the illustrated method steps not shown in detail, the at least two mold halves 10, 11 may not be completely closed during the injection of the plasticized polymer material 2, and the mold halves 10, 11 may only be closed during the solidification process of the polymer material 2. Alternatively, or in combination, the mold halves 10, 11 may be opened due to the internal pressure increasing during the injection of the polymer material 2, and the mold halves 10, 11 may only be closed again during the solidification process of the polymer material 2.

[0032] In the Fig. 9 and Fig. 10 are analogous to those in Fig. 1 and Fig.2 described cover elements are shown, wherein these cover elements are designed as brand emblems and additionally have a brand logo applied to the main body 1 or injected into the main body 1.

Claims

[1] Cover element, in particular for the external cladding of a motor vehicle, comprising: - an injection-molded main body (1) made of a transparent or translucent polymer material (2) and, - a carrier film (3) with at least one heating conductor (4) applied to the carrier film (3) or with at least one heating layer applied to the carrier film (3), which can be heated by current or by radiation, wherein the carrier film (3) has a film thickness T and at least one side edge (5), wherein the carrier film (3) is connected to the main body (1) at least in the region of the side edge (5) by means of a back-injection of the carrier film (3) or by means of an over-injection of the carrier film (3) with the polymer material (2) of the main body (1), characterized by , that in the region of the at least one side edge (5), the film thickness T decreases to a thinner film thickness t at the side edge (5), so that the visual recognizability of the transition (U) from the carrier film (3) to the polymer material (2) of the main body (1) adjacent to the carrier film (3) is minimized. [2] Cover element according to claim 1, characterized by that in the case of over-injection, the film thickness T decreases from the side (A) of the carrier film (3) oriented in the direction of a designated visible side (S) of the main body (1) to the thinner film thickness t and in the case of back-injection, the film thickness T decreases from the side (B) of the carrier film (3) oriented away in the direction of the designated visible side (S) of the main body (1) to the thinner film thickness t. [3] Cover element according to claim 1 or 2, characterized bythat the thinner film thickness t is at least 40%, preferably at least 60%, particularly preferably at least 80% thinner than the film thickness T. [4] Cover element according to one of the preceding claims, characterized by that the transparent polymer material (2) comprises a polycarbonate, polymethyl methacrylate, polyamide, polyolefin, polypropylene, polyethylene or acrylonitrile-butadiene-styrene copolymer or consists of one of these materials. [5] Cover element according to one of the preceding claims, characterized by that the cover element forms or is used for a cover for a sensor or a cover for a radar unit or a cover for a camera or a cover for a lidar unit or a cover for a lighting unit. [6] Cover element according to one of the preceding claims, characterized bythat the carrier film (3) is bevelled in the region of the side edge (5) at an angle (α) of 20° to 75°, preferably at an angle (α) of 30° to 60°, and as a result the film thickness T decreases to the thinner film thickness t at the side edge (5). [7] Cover element according to one of the preceding claims, characterized by that in the region of the side edge (5) in a cross-section of the carrier film (3) the film thickness T decreases in an elliptically formed curve from the film thickness T to the thinner film thickness t at the side edge (5). [8] Cover element according to one of the preceding claims, characterized by that the carrier film (3) consists of a material which is compatible, of the same type or identical to the polymer material (2) of the main body (1). [9] Method for producing a covering element, in particular for the outer lining of a motor vehicle, wherein the covering element comprises an injection-molded main body (1) made of a transparent polymer material (2) and a carrier film (3) with at least one heating conductor (4) applied to the carrier film (3) or with at least one heating layer applied to the carrier film (3), comprising the following steps: - Providing a carrier film (3) with a heating conductor (4) applied to the carrier film (3) or with at least one heating layer applied to the carrier film (3), which can be heated by current or by radiation, wherein the carrier film (3) has a film thickness T and at least one side edge (5), - arranging the carrier film (3) in a cavity (12) of an injection moulding tool (13) formed between at least two tool halves (10, 11) and defining a main body (1), - injecting a plasticized polymer material (2) into the cavity (12) of the injection mold (13) to form the main body (1), - connecting the carrier film (3) to the main body (1) at least in the region of the side edge (5) by back-injection of the carrier film (3) or by over-injection of the carrier film (3) with the polymer material (2) of the main body (1), - Cooling and demoulding the cover element thus formed, characterized by , that in the region of the at least one side edge (5), the film thickness T decreases to a thinner film thickness t at the side edge (5), so that the visual recognizability of the transition (U) from the carrier film (3) to the polymer material (2) of the main body (1) adjacent to the carrier film (3) is minimized. [10] Method according to claim 9, characterized bythat at least one of the tool halves (10) of the injection molding tool (13) has an additional heating means (14) in the region of the side edge (5) of the carrier film (3) arranged in the cavity (12), which heating means enables a locally increased temperature of the at least one tool half (10) in the region of the side edge (5) of the carrier film (3) compared to the remaining at least one tool half (10). [11] Method according to claim 9 or 10 characterized by that the at least two tool halves (10, 11) are not completely closed during the injection of the plasticized polymer material (2) and the tool halves (10, 11) are only closed during the solidification process of the polymer material (2) or due to the internal pressure increasing during the injection of the polymer material (2), the tool halves (10, 11) are opened and the tool halves (10, 11) are only closed again during the solidification process of the polymer material (2).

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