Method for manufacturing a molded part designed as a decorative part or trim part for the interior of motor vehicles

Abstract

Method for manufacturing a molded part (1) designed as a decorative part or trim part for the interior of motor vehicles, formed with a carrier (2) made of plastic for the fastening arrangement of the molded part (1) in the motor vehicle and a decorative composite (3) comprising a decorative layer (4) made of a fabric and a decorative carrier layer (5), wherein the decorative layer (4) faces a visible side of the molded part and, when forming the decorative composite (3), a film (6) is arranged on the decorative carrier layer (5) on a side opposite the decorative layer (4), wherein the decorative layer (4), the decorative carrier layer (5) and the foil (6) are packaged and then fed in the packaged state to a forming tool, wherein the decorative composite (3) is first formed in one operation by simultaneously joining and forming the decorative layer (4) and the decorative carrier layer (5) in the forming tool, and the decorative composite (3) is brought into a final shape in the forming tool as a molded part forming the shape of the molded part to be produced, and subsequently, the decorative composite (3) is directly back-injected with the carrier (2) in an injection molding tool on a side opposite the visible side, wherein the film (6) is designed as an adhesive film and is designed to protect and reinforce the decorative composite (3) during the joining and forming of the decorative layer (4) and the decorative carrier layer (5).

Description

[0001] The invention relates to a method for manufacturing a molded part designed as a decorative or trim part for the interior of motor vehicles. The molded part comprises a decorative composite consisting of a decorative layer made of a fabric and a decorative carrier layer, as well as a carrier provided on the back.

[0002] Various materials are used as decorative layers for molded parts designed as decorative or cladding components. The decorative layer forms the visible surface and can be made of, for example, wood, aluminum, or a fabric, with the manufacturing processes differing depending on the material. The present invention relates to a decorative layer made of a fabric.

[0003] Prior art methods are known in which a carrier is first produced that defines the shape of the molded part and allows the part to be attached to the vehicle. The fabric serving as a decorative layer is then prepared, for example, by applying a primer. The carrier must be cleaned before the decorative layer can be manually applied and bonded in a press using an adhesive previously applied to the carrier or the decorative layer. Alternatively, the decorative layer can be directly injection-molded onto the back of the carrier.

[0004] Prior art in the present technical field is disclosed, for example, in documents DE 10 2009 016 177 A1, EP 2 298 528 A1, DE 20 2007 019 046 U1 and DE 20 2019 101 689 U1. None of the aforementioned documents provides for a film designed as an adhesive film on a side of the decorative substrate layer opposite the decorative layer.

[0005] The invention is therefore based on the objective of providing a manufacturing process for molded parts with a fabric as a decorative layer, which is automated using machines and can therefore be carried out faster and more cost-effectively.

[0006] This problem is solved by the combination of features according to claim 1.

[0007] According to the invention, a method for manufacturing a molded part, designed as a decorative or trim part for the interior of motor vehicles, is proposed, comprising a plastic carrier for securing the molded part in the motor vehicle and a decorative composite. The decorative composite comprises a decorative layer made of a fabric and a decorative carrier layer, the decorative layer facing a visible side of the molded part. The visible side is thus defined as the side that the observer sees when the molded part is installed in the vehicle.

[0008] In the inventive process, the decorative composite is first formed in a single operation by simultaneously joining and forming the decorative layer and the decorative carrier layer in a forming tool. The decorative composite is then placed in an injection mold and directly back-injected with the carrier on one side opposite the visible side. The process steps are therefore performed entirely by machine and can thus be automated. The cycle times are significantly shorter compared to methods known from the prior art.

[0009] A hot press, for example, is used as a forming tool. Furthermore, the process stipulates that the decorative composite is formed within the forming tool into a final shape that defines the form of the part to be manufactured. The forming piece is primarily pressed into a shell mold, into which the plastic carrier is subsequently injected in the injection molding machine. The front side of the shell, opposite the shell and the carrier, i.e., the visible side of the shell, forms the front of the part visible in the assembled state.

[0010] In the method according to the invention, a film reinforcing the decorative substrate layer is positioned on the side of the decorative substrate layer facing away from the visible side during the formation of the decorative composite. The film protects and reinforces the decorative composite during the bonding and forming of the decorative layer and the decorative substrate layer.

[0011] According to the invention, the decorative composite is formed from the decorative layer, the decorative carrier layer, and the film, packaged together, and then fed to the forming tool in its packaged state. The components to be joined and formed are pre-assembled in a sandwich structure and their size is adapted to the required dimensions.

[0012] According to the invention, the film is designed as a glue film.

[0013] In the method according to the invention, the decorative carrier layer is, in an advantageous embodiment, designed as a laminating fleece.

[0014] Furthermore, a further development of the process provides that the decorative carrier layer, designed as a laminating fleece, is coated with adhesive which is activated by pressure and heat during the production of the decorative composite in the forming tool, thus creating the bond to the decorative layer. The laminating fleece can, for example, be resin-impregnated with adhesive for this purpose.

[0015] The preferred fabric type for the decorative layer in this process is a carbon fabric. However, other fabrics, such as metal fabrics, can also be used.

[0016] In one embodiment of the process, the decorative layer completely covers one side of the decorative composite facing the visible side. In this case, only the decorative layer is visible on the visible side of the molded part.

[0017] A further development of the process involves coating the decorative composite with a protective lacquer, such as a PUR lacquer, after the substrate has been back-injected. This protects the front, i.e., the visible side of the molded part.

[0018] After the carrier is back-injected onto the decorative composite, conventional and state-of-the-art post-processing can be carried out, such as the removal of excess material or phases.

[0019] The invention also includes not only the method described above, but also the molded part produced using the method in its various embodiments.

[0020] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a schematic representation of a decorative composite for the production of a molded part before forming in a perspective view; Fig. 2 the decorative composite made of Fig. 1 after joining and reshaping in a sectional view; Fig. 3 the manufactured molded part with carrier and the decorative composite made of Fig. 2; Fig. 4 an alternative structure of the decorative composite; Fig. 5 another alternative structure of the decorative composite.

[0021] The figures are schematic examples and serve to better understand the process and the resulting molded part.

[0022] Fig. Figure 1 shows the preparation and packaging of a decorative layer 4 made of carbon fabric and a decorative carrier layer 5 formed from a laminating fleece. The film 6, in particular an adhesive film, is applied to the reverse side of the decorative carrier layer 5, i.e., to a side facing away from the visible side. This pre-conditioned sandwich structure is fed to the forming tool, for example, a hot press, where it is mechanically bonded and simultaneously formed into the decorative composite 3. The production of the decorative composite 3 thus takes place in a single operation. The resulting decorative composite 3 is shown schematically in Figure 1. Fig. Figure 2 shows the mold being formed into its final shape, which the molded part 1 should have on the visible side after the process. In the example shown, this is a shell mold for producing a decorative part for the vehicle interior. The decorative carrier layer 5, designed as a laminating fleece, is provided with adhesive, which is activated by pressure and heat during the production of the decorative composite 3 in the forming tool and creates the bond between the laminating fleece and the decorative layer 4.

[0023] The decorative composite 3 is removed from the forming tool, and the film 6 is optionally removed or left on the component. The decorative composite 3 is then placed in the injection mold and back-injected with the plastic carrier 2 on the side of the decorative carrier layer 5. The resulting molded part 1 is in Fig. 3 shown. The carrier 2 fills the shell shape of the decorative composite 3 and stiffens the molded part 1.

[0024] The carrier 2 also has one-piece fastening elements 7 with which the molded part 1 can be fastened in the vehicle interior. The fastening elements 7 are only shown schematically and can, for example, be designed as hooks or clips.

[0025] In an alternative version according to Fig. 4. The structure of the decorative composite 3 is modified such that the order of the decorative carrier layer 5 and the foil 6, in particular the adhesive foil, is reversed. Otherwise, the embodiment and its manufacture correspond to that of the Fig. 1-3 match.

[0026] In another alternative version according to Fig. In section 5, a slide 6 is omitted. Otherwise, the embodiment and its manufacture correspond to that of the Fig. 1-3 agree. A version in which a film 6 is initially used, but removed before back-injecting the carrier 2, also yields the result according to Fig. 5.

[0027] Not shown, but also included as an alternative variant, is a version of molded part 1 according to the Fig. 3, Fig. 4 or Fig. 5, which is subsequently provided with a protective layer, in particular a protective varnish, on the decorative layer 4. Without such a protective layer, it is advantageous that the fabric is perceptible to the touch.

[0028] Although a carbon fabric is preferred as decorative layer 4, the same beneficial effects are achieved with other types of fabric.

Claims

[1] Method for manufacturing a molded part (1) designed as a decorative part or trim part for the interior of motor vehicles, formed with a carrier (2) made of plastic for the fastening arrangement of the molded part (1) in the motor vehicle and a decorative composite (3) comprising a decorative layer (4) made of a fabric and a decorative carrier layer (5), wherein the decorative layer (4) faces a visible side of the molded part and, when forming the decorative composite (3), a film (6) is arranged on the decorative carrier layer (5) on a side opposite the decorative layer (4), wherein the decorative layer (4), the decorative carrier layer (5) and the foil (6) are packaged and then fed in the packaged state to a forming tool, wherein the decorative composite (3) is first formed in one operation by simultaneously joining and forming the decorative layer (4) and the decorative carrier layer (5) in the forming tool, and the decorative composite (3) is brought into a final shape in the forming tool as a molded part forming the shape of the molded part to be produced, and subsequently, the decorative composite (3) is directly back-injected with the carrier (2) in an injection molding tool on a side opposite the visible side, wherein the film (6) is designed as an adhesive film and is designed to protect and reinforce the decorative composite (3) during the joining and forming of the decorative layer (4) and the decorative carrier layer (5). [2] Method according to claim 1, characterized by , that the decorative carrier layer (5) is designed as a laminating fleece. [3] Procedure according to the previous claim, characterized by, that the decorative carrier layer (5) designed as a laminating fleece is provided with adhesive which is activated by pressure and heat during the production of the decorative composite (3) in the forming tool and establishes the connection to the decorative layer (4). [4] Method according to any of the preceding claims, characterized by , that the decorative layer (4) is formed from a carbon fabric. [5] Method according to any of the preceding claims, characterized by , that the decorative layer (4) completely covers one side of the decorative composite (3) facing the visible side. [6] Method according to any of the preceding claims, characterized by , that the decorative composite (3) is coated with a protective lacquer after the back injection of the carrier (2).

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