阅读说明：本技术 用于生产车辆包层零件的方法 (Method for producing cladding parts for vehicles ) 是由 U·施纳贝尔 于 2018-09-25 设计创作，主要内容包括：本发明涉及一种用于生产车辆的包层零件的方法,所述包层零件具有在安装状态下形成包层的包层零件主体,其中形成了在平面中二维地延伸的夹层面板,所述夹层面板具有至少一个透明的热塑性上部层、预制的无后处理的过渡层和热塑性基底层,其中随后在热量的影响下使所述至少三层的夹层板三维地成形到形成所述包层零件主体的夹层元件中。(The invention relates to a method for producing a clad part for a vehicle, having a clad part body which forms a cladding in the mounted state, wherein a sandwich panel is formed which extends two-dimensionally in a plane, having at least one transparent thermoplastic upper layer, a pre-fabricated transition layer without post-treatment and a thermoplastic base layer, wherein the at least three-layer sandwich plate is subsequently three-dimensionally shaped under the influence of heat into a sandwich element which forms the clad part body.)

1. A method for producing a cladding part for a vehicle, which cladding part has a cladding part body which in the mounted state forms a panel, wherein a sandwich panel extending two-dimensionally in a plane is formed, which sandwich panel has at least one transparent thermoplastic upper layer, a pre-processed transition layer without post-treatment and a thermoplastic base layer, wherein the at least three-layer sandwich panel is subsequently three-dimensionally shaped under the influence of heat into a sandwich element forming the cladding part body.

2. The method of claim 1, wherein at least the base layer is applied to the transition layer during tape lamination.

3. The method according to claim 1 or 2, characterized in that the upper layer is applied to the transition layer in a strip lamination process or in a continuous painting process.

4. A method according to claim 2 or 3, wherein the transition layer is dehumidified during the tape lamination process.

5. A method according to any one of the preceding claims, characterised in that the sandwich panel is produced in a masticated strip process and cut to size from the strip to form a predetermined final shape of the clad part body prior to said forming.

6. Method according to any of the preceding claims, characterized in that the pre-finished non-post-treated transition layer is formed by a pre-finished veneer, pre-coloured paper, pre-finished film, fabric or decorative support, in particular a real carbon fabric layer.

7. Method according to any of the preceding claims, characterized in that the pre-finished transition layer without post-treatment is formed by the layer of the sandwich panel corresponding to neutral fibres.

8. Method according to any one of the preceding claims, characterized in that the thermoplastic upper layer is formed by a thermoplastic polyurethane film and/or at least one layer made of polyurethane lacquer.

9. Method according to any one of the preceding claims, characterized in that the thermoplastic substrate layer is formed by a layer of thermoplastic polyurethane and/or a laminate comprising thermoplastic with a woven fabric.

10. Method according to any one of the preceding claims, characterized in that the upper layer has a layer thickness of 0.2-0.4 mm, the transition layer has a layer thickness of 0.2-0.3 mm and the base layer has a layer thickness of 0.15-0.3 mm, wherein in particular the upper layer, the transition layer and the base layer each have the same layer thickness.

11. A method according to any of the preceding claims, characterized in that a layer made of polyurethane lacquer is applied to the upper layer of the three-dimensionally shaped clad part body as a surface finishing layer.

12. A method according to any one of the preceding claims, characterised in that the base layer of the sandwich element forming the body of the clad part is back-injected with plastic in an injection moulding process.

13. Method according to any one of the preceding claims, wherein the transition layer is formed by a pre-coloured veneer, a pre-processed film or a pre-coloured paper, and the upper layer is formed by a polyurethane lacquer layer and a thermoplastic polyurethane film layer, and wherein a fabric layer is arranged between the polyurethane lacquer layer and the thermoplastic polyurethane film layer.

14. Method according to the preceding claim, characterized in that a shrink-proof fabric layer is supplied as a roll material via a roller and laid on the sandwich panel.

15. A clad part produced according to the method of the preceding claim.

Technical Field

The invention relates to a method for producing a cladding or decorative part of a vehicle, in particular of a vehicle interior.

Background

In the prior art, common cladding parts are used as interior cladding, for example instrument panel cladding for motor vehicles. In the mounted state, usually only the cladding part body of the cladding part can be seen, since the rear bracket structure or the holding element is countersunk in the dashboard or in another fastening position. The cladding part body thus forms the visible side of the cladding part and typically comprises an appearance determining layer, such as a wood veneer, a carbon fabric or an aluminium layer.

On the basis of the example of a clad part with a wood-faced appearance, the latest standard production process of clad parts according to the prior art comprises the step of producing a faced blank in the desired part size, the faced blank being single-sided laminated with plastic, so that a double-layered intermediate product is obtained. Subsequently, the veneer is calibrated to the desired thickness, the double-laminated veneer blank is three-dimensionally shaped into the desired final shape of the cladding part body, and the carrier structure is back-injection molded onto the side of the cladding part body where the laminate is positioned. Followed by surface post-treatment and repair steps and coloring of the finish to the desired appearance. Finally, an adhesion promoter (primer) and a surface treatment lacquer made of polyurethane are applied to the veneer, wherein the primer needs to form an adhesion with the polyurethane lacquer.

The standard process provides high quality clad parts. Disadvantageously, however, the forming radius is limited during the three-dimensional forming of the laminate facer or carbon fabric. At very small radii, in particular at radii smaller than 2.5mm, cracks or fractures are easily formed in the veneer or in the carbon layer, respectively, because the yield strength of the material is exceeded. Furthermore, because of the retention time required in the mold, the forming can only be performed very slowly, which ensures that residual moisture does not remain in the finish. Furthermore, it is generally necessary to pass through a large number of production steps, which means that a large amount of time is required.

Disclosure of Invention

The invention is therefore based on the object of providing a method for producing clad parts which provides the option of achieving very small forming radii. Furthermore, the invention aims to meet the preconditions for a faster and more economical implementation, so that the production time per clad part is shortened.

This object is achieved by a combination of the features according to claim 1.

According to the invention, a method for producing a clad part for a vehicle is proposed, the clad part having a clad part body forming a cladding in a mounted state. During the method, a sandwich panel is formed which extends in two dimensions in a plane and has at least one transparent thermoplastic upper layer, a pre-processed transition layer without post-treatment and a thermoplastic substrate layer. The sandwich panel of at least three layers thus obtained is subsequently three-dimensionally formed under the influence of heat into the sandwich element forming the body of the cladding part.

In this case, there is a distinction between the term clad part and the clad part body. The cladding part body represents the visible main element of the cladding part in the mounted state and may even be formed separately, for example in case gluing is to be performed. However, one embodiment of the method according to the invention is to provide the cladding part body with further elements, such as bracket parts or fastening means (e.g. clips, hooks, latches) or frames, which then also become elements of the cladding part.

To define the direction, the upper layer is oriented towards the front visible side of the cladding part, while the base layer is oriented towards the rear or mounting side. The pre-processed transition layer without post-processing is characterized in that it has the desired final state from the beginning. Possible coloration has already occurred. The transition layer thickness also corresponds to the desired layer thickness defined previously. In a preferred embodiment variant, the pre-finished transition layer without aftertreatment is formed by a pre-colored finish, a film, a fabric (e.g. carbon fabric), a pre-colored paper or a corresponding decorative support available in the art.

The method according to the invention first establishes a two-dimensional sandwich panel of at least three layers. The transition layer necessary for the appearance of the clad part is protected on both sides by a thermoplastic upper layer and a thermoplastic base layer. The thermoplastic material of the upper layer and the base layer can be formed three-dimensionally under the influence of heat together with the transition layer, wherein the upper layer and the base layer protect the transition layer in the process step of forming by pressure on both sides, thus increasing the yield strength of the transition layer even at very small radii and preventing cracking or breaking. In this case, the temperature is established at a minimum which is sufficiently high that the respective thermoplastic material used is subjected to the shaping process without damage or visible loss. One advantageous temperature value is the corresponding glass transition temperature Tg of the thermoplastic.

The method according to the invention is characterized in one embodiment variant in that at least the base layer is applied to the transition layer during the lamination of the strip. The strip lamination process is performed by supplying the transition layer as strip material from a roll and subsequently laminating onto the thermoplastic substrate layer.

In one embodiment according to the invention, the top layer is applied to the transition layer in a tape lamination process or in a continuous painting process. Two-dimensional sandwich panels allow the size of the web or strip to be the starting loop material. In this case, it is furthermore advantageous to completely dehumidify the transition layer already during the lamination of the strip.

If a strip lamination process is used, the sandwich panel is produced in a hot strip (strip run) process and cut to size from the strip prior to forming to form the predetermined final shape of the body of the clad part. The production duration of the sandwich panel of at least three layers with transition layers which already have the desired final state with regard to its coloration and surface structure and the cutting of the individual sandwich panel sections to the appropriate size from the strip before the start of the forming process have greatly shortened the production time of the base material relative to the described standard process.

In the method according to the invention, the forming process itself also requires less time consumption. The forming can be carried out faster due to the provision of the sandwich panel with at least three layers of the upper layer and the substrate layer. The hold time in the forming tool is also significantly less because moisture removal has already taken place during lamination of the substrate layer.

An advantageous exemplary embodiment provides that the upper layer has a layer thickness of 0.2mm to 0.4mm, the transition layer has a layer thickness of 0.2mm to 0.3mm, and the base layer has a layer thickness of 0.15mm to 0.3 mm. In a particularly advantageous solution, the layer thicknesses of the upper layer, the transition layer and the base layer are in each case identical. This results in the formation of a pre-finished, non-post-treated transition layer as the layer of the sandwich panel corresponding to the neutral fibre (also called neutral wire). The neutral fibres in the forming process are layers of a sandwich panel cross-section, the length of which does not change when bent. Thus, in the best case during the forming process, the transition layer as an intermediate layer is stress-free, whereas in any case the traction, compression and shear tension forces on the transition layer are reduced during the three-dimensional forming of the sandwich panel.

The thermoplastic upper layer is preferably formed by a thermoplastic polyurethane film (TPU film) and/or at least one layer made of polyurethane lacquer (e.g. polyurethane DD lacquer), and the thermoplastic base layer is formed by a thermoplastic polyurethane layer and/or a laminate comprising thermoplastic with woven fabric. In this case, the thermoplastic polyurethane layer may also be a TPU film as an exemplary embodiment.

The method according to the invention also provides for a layer made of polyurethane lacquer to be applied as a surface finishing layer to the upper layer of the three-dimensionally shaped clad part body. Furthermore, the use of a thermoplastic polyurethane film and/or at least one layer made of polyurethane lacquer for the upper layer has the advantage that adhesion promoters (primers) can be omitted in order to apply the surface treatment layer. Since both the upper layer and the surface finishing layer are formed of the same material or at least of a polyurethane material, the layers form a permanent solid bond even without a primer, for example in the RIM process (reaction injection moulding process). Thus, the transition layer is formed without the use of a primer. The additional step of applying a primer described in standard methods can be avoided. This further shortens the production duration and reduces the production costs.

In a further development of the method, after the shaping, the base layer of the sandwich element forming the body of the cladding part is back-injected with plastic in an injection molding process. In this case, a variation of injection compression molding is also included. In injection compression molding, a pattern is created on the transition layer during injection molding via injection pressure through the base layer without fracture or cracking. The pattern is defined by the tool inner wall and is therefore variably definable. Furthermore, in this way, a predetermined structure for the surface of the groove or transition layer of the raised strip can be created in this way with high repetition accuracy.

As a further combination variant, the method according to the invention comprises forming the transition layer, in particular by means of a pre-pigmented veneer, film or pre-pigmented paper, and forming the upper layer from a polyurethane lacquer layer and a thermoplastic polyurethane film layer, and arranging the textile layer between the polyurethane lacquer layer and the thermoplastic polyurethane film layer. The fabric layer is preferably formed as a metal fabric so that a metal combination can be produced on the veneer or paper. In one exemplary embodiment, the shrinkproof fabric layer is supplied as a roll via rollers and laid or stretched precisely on the sandwich panel. The attachment to the surface finishing layer is still provided only via the polyurethane material.

In addition to the method, the invention also includes clad parts produced according to exemplary embodiments of the above-described method.

Drawings

Further advantageous further developments of the invention are characterized in the dependent claims and/or are described in more detail below together with the description of preferred embodiments of the invention with reference to the drawings. In the drawings:

FIG. 1 shows a flow chart of a method sequence according to the invention;

fig. 2 shows a comparison of the method according to the invention with a standard method.

Detailed Description

In fig. 1, a process sequence is illustrated by way of example for using the heated bar process and providing the starting material of the transition layer from a roll. A pre-colored finish or carbon fabric without post-treatment is provided as an intermediate layer. Subsequently, in the tape lamination process, a TPU film or thermoplastic with a textile as substrate layer is produced on the transition layer. If a facing is used, moisture removal has already been performed during tape lamination. The upper layer may optionally be applied to the visible side of the transition layer in a tape lamination process and/or a painting process, with polyurethane DD paints being preferred as the paint. The resulting sandwich panel is in a heated strip process corresponding to a ring-shaped material from which elements are cut and subsequently a clad part body is formed. Thus defining the outer dimensions of the body of the cladding part, while the sandwich panel is still a two-dimensional plate. Subsequently, the shaping is performed by introducing heat, so that the three-dimensional clad part body forms its final shape. For example, the back side, i.e., the substrate layer, is formed using back injection molding to apply the bracket structure. On the front side, a surface finishing layer made of polyurethane lacquer is applied to the upper layer of the cladding part body.

Fig. 2 compares the advantages of the process according to the invention in the embodiment according to fig. 1 with the advantages of the standard process described. In the process according to the invention, a plurality of process steps, such as, for example, lamination and alignment of each individual component, surface treatment and repair of the veneer or fabric, colouring of the veneer, film or fabric, and priming, are no longer necessary. Admittedly, although the cost of the pre-processed non-aftertreated starting material of the transition layer (i.e. the corresponding finished and already pigmented finish or (carbon) fabric or the corresponding film) is more expensive, the present additional expenditure is more than offset in the course of the process. The method according to the invention reduces the production time required per clad part by about 50% and the production costs by about 30% with respect to standard processes. In this case, even the passage time of the components, the discarding cost, and the evaluation of the logical area between the individual processes are not considered.