Component for a vehicle body outer skin, prepeg for a component for a vehicle body outer skin, and method for producing a component for a vehicle body outer skin

Abstract

According to the invention, a component for a vehicle body outer skin is made of a fiber-reinforced plastic or a fiber-plastic composite. The fiber-plastic composite comprises multiple fiber layers. The fiber-plastic composite comprises two synthetic fiber outer layers made of a textile sheet material consisting of synthetic fibers, and at least one natural fiber intermediate layer made of a textile sheet material consisting of natural fibers. The natural fiber intermediate layer is interposed between the two natural fiber outer layers.

Description

[0001] Body outer skin component, prepreg for a body outer skin component and method for producing a body outer skin component

[0002] The invention relates to a body outer skin component for a motor vehicle body, for example a passenger car or a commercial vehicle, a prepreg for a body outer skin component and a method for producing a body outer skin component.

[0003] The body of a passenger car is typically constructed using a self-supporting shell construction. The body is usually made of steel or aluminum, or a combination of these materials. Sometimes an outer body shell component is also made of a fiber-plastic composite, such as carbon fiber or glass fiber.

[0004] It is also known to produce a fiber-plastic composite using natural fibers. Natural fibers are generally hygroscopic, meaning they can absorb moisture over time, even within a fiber-plastic composite. Natural fibers are made from a renewable resource and have the advantage of generally having a better carbon footprint than synthetic fibers.

[0005] It is the object of the present invention to provide a body outer skin component made of a fiber-plastic composite, a prepreg for a body outer skin component and a method for producing a body outer skin component, wherein the body outer skin component is produced more sustainably and has a consistent surface quality over time, for example a consistent optical surface quality.

[0006] This object is achieved by an outer body skin component having the combination of the features of claim 1. Furthermore, this object is achieved by a prepreg according to claim 11 and a method according to claim 12. Advantageous developments are recited in the dependent claims. According to the invention, an outer body skin component is made of fiber-reinforced plastic or of a fiber-plastic composite. The fiber-plastic composite has a plurality of fiber layers. The fiber-plastic composite has two or exactly two chemical fiber outer layers made of a textile fabric consisting of chemical fibers and at least one or exactly one natural fiber intermediate layer made of a textile fabric consisting of natural fibers. The natural fiber intermediate layer is arranged between the two chemical fiber outer layers.

[0007] The chemical fiber outer layer with the textile fabric consisting of chemical fibers, together with a plastic matrix of the fiber-plastic composite, inhibits moisture diffusion so that little or no moisture from the outside reaches the natural fiber intermediate layer. The chemical fibers are not hygroscopic or less hygroscopic than natural fibers. This prevents or at least limits the hygroscopic natural fibers of the fiber intermediate layer from absorbing moisture. Moisture absorption by the natural fibers of the natural fiber intermediate layer can cause the natural fibers to swell, i.e., increase in volume. The swelling of the natural fibers of the intermediate layer, in turn, affects a surface of the body outer skin component, i.e., the surface of the body outer skin component changes. This makes the surface of the body outer skin component more wavy, i.e., less smooth or more uneven.The change in the surface of the body outer skin component is visible and can be perceived by the user as aging of the body outer skin component and thus as a loss of quality. Furthermore, a change in the surface of the body outer skin component also has the disadvantage that contaminants can adhere more easily. Likewise, a change in the surface of the body outer skin component can also be detrimental to any other function of the body outer skin component that requires a consistent or as smooth a surface as possible. Thanks to the natural fibers, the body outer skin component has a better CO2 footprint during production. To further improve the CO2 footprint, the chemical fibers can be made from recycled material. The body outer skin component can also be a body add-on part.The body outer skin component can be screwed, riveted, clipped and / or glued to the body of the motor vehicle.

[0008] Preferably, the intermediate layer is directly adjacent to the outer layer, i.e., no additional fiber layer is arranged between the chemical fiber outer layer and the natural fiber intermediate layer. This simplifies the construction of the body shell component with just a few layers, and a sufficiently thin-walled body shell component can be produced.

[0009] The chemical fiber outer layers are preferably formed by a knitted fabric.

[0010] A knitted fabric has the advantage of a high resin impregnation, which in turn is advantageous in terms of moisture diffusion inhibition.

[0011] Alternatively, the chemical fiber outer layers can also be formed by a woven fabric or a non-woven fabric.

[0012] The chemical fiber outer layers advantageously have a basis weight of 50 g / m 2 up to 450 g / m 2 , especially 100 g / m 2 up to 250 g / m 2 , for example 130 g / m 2 . The basis weight refers only to the outer layer of synthetic fibers and not to the outer layer of synthetic fibers with the plastic resin.

[0013] The chemical fibers can be organic or inorganic. Organic chemical fibers include, for example, synthetic polymers. The chemical fiber outer layers are preferably made of PES fibers, i.e., polyester fibers. PES fibers are inexpensive, readily available, can be produced very thin, and are of homogeneous quality. PES fibers also advantageously do not absorb moisture. Furthermore, PES fibers exhibit good UV resistance, which also contributes to the optical quality of the surface of the body outer skin component.

[0014] Furthermore, the natural fiber intermediate layer is preferably formed from a woven fabric or a scrim.

[0015] The natural fiber interlayer advantageously has a surface weight of 100 g / m 2 up to 600 g / m 2 , especially 200 g / m 2 up to 400 g / m 2 , for example 300 g / m 2 . The basis weight refers only to the natural fiber interlayer and not to the natural fiber interlayer with the plastic resin.

[0016] The natural fibers of the natural fiber interlayer are preferably plant fibers, for example bast fibers, in particular flax fibers or hemp fibers or bamboo fibers, etc., or seed fibers or leaf fibers.

[0017] A layer of paint, in particular a clear coat or a colored coat, is preferably applied to the outside of the body outer skin component.

[0018] The paint layer can also reduce the diffusion of moisture into the outer body skin component.

[0019] The layers of the body outer skin component are preferably constructed symmetrically to the central layer.

[0020] A plastic matrix of the fiber-plastic composite is advantageously a thermosetting plastic that is produced with a liquid resin, in particular an epoxy resin, and a corresponding hardener.

[0021] According to a preferred embodiment, the two synthetic fiber outer layers and the natural fiber intermediate layer are part of a single prepreg. A prepreg is a resin-impregnated semi-finished product—the resin is not yet cured or activated.

[0022] A single prepreg has advantages when manufacturing the body outer skin component, as only one prepreg needs to be handled and inserted into one tool.

[0023] According to an alternative development, the two chemical fiber outer layers and the natural fiber intermediate layer are each formed in a single prepreg. In other words, the body outer skin component is formed with one prepreg containing the natural fiber intermediate layer and two prepregs containing the chemical fiber outer layers—i.e., with three prepregs. The body outer skin component can be a vehicle roof outer skin, a fender outer skin, a front cover outer skin, a side panel outer skin, a sill panel, or a bumper panel.

[0024] According to a further aspect, the present invention relates to a prepreg for a body outer skin component as described above, comprising two chemical fiber outer layers comprising a textile fabric consisting of chemical fibers and at least one natural fiber intermediate layer arranged between the chemical fiber outer layers comprising a textile fabric consisting of natural fibers.

[0025] According to a further aspect, the present invention relates to a method for producing a body outer skin component according to the invention as described above by means of an autoclave process or by means of press molding using a single prepreg with the chemical fiber outer layers and the natural fiber intermediate layer or one prepreg each for the chemical fiber outer layers and the natural fiber intermediate layer.

[0026] Chemical fibers according to the present invention are synthetically produced organic or inorganic fibers and can therefore be, among other things, so-called plastic fibers. In particular, chemical fibers are non-metallic fibers. Natural fibers, in turn, are non-synthetically produced fibers that occur naturally, for example, in plants, and are obtained, for example, from plants without synthesis. Natural fibers are not plastic fibers. In particular, plastic fibers that are synthesized or produced from hydrocarbons obtained from plants are not natural fibers within the meaning of the present invention.

[0027] The features mentioned above can be combined with each other as far as possible and reasonable.

[0028] A brief description of the figure follows.

[0029] Figure 1 is a schematic sectional view of a body outer skin component according to an embodiment of the present invention. An embodiment of the present invention will be explained below with reference to Figure 1.

[0030] Figure 1 shows a schematic section through a body outer skin component 1, in particular a vehicle roof outer skin, made of fiber-reinforced plastic or a fiber-plastic composite according to the exemplary embodiment of the present invention. The fiber-plastic composite is produced by an autoclave process or compression molding using one or more prepregs. The section shows the individual layers of the fiber-plastic composite. The layers of the fiber-plastic composite differ in terms of the fiber layers, i.e. the fiber-plastic composite has several fiber layers, which are all embedded in the same plastic matrix. The fiber-plastic composite has two outer chemical fiber layers 3 and an inner natural fiber intermediate layer 5. The chemical fiber outer layers 3 are thus on the outer sides of the body outer skin component 1.The natural fiber intermediate layer 5 is arranged adjacent to the chemical fiber outer layers 3 between the chemical fiber outer layers 3. The chemical fiber outer layers 3 are preferably formed from a knitted fabric made of PES fibers. The PES knitted fabric allows the chemical fiber outer layers 3 to be impregnated with a relatively large amount of resin. The natural fiber intermediate layer 5 is preferably formed from a woven fabric made of flax fibers.

[0031] The chemical fiber outer layers 3 made of PES fibers, together with the resin, inhibit moisture diffusion, so that less moisture from the outside reaches the natural fiber intermediate layer 5. Neither the resin itself nor the chemical fibers of the chemical fiber outer layers 3 absorb moisture. The thicker the chemical fiber outer layers 3 are together with the resin, the lower the moisture diffusion to the natural fiber intermediate layer 5. This prevents or at least limits the hygroscopic flax fibers of the natural fiber intermediate layer 5 from absorbing moisture during operation of the motor vehicle with the body outer skin component 1. Moisture absorption by the natural fibers would cause the natural fiber intermediate layer 5 to swell, which would also be visible to a user of the motor vehicle on the surface of the body outer skin component 1.A change in the surface of the body outer skin component 1 would be visible, which could be perceived as aging of the body outer skin component 1 and thus represent a loss of quality. Furthermore, a less smooth surface leads to easier adhesion of dirt.

[0032] There is no additional fiber layer between the chemical fiber outer layers 3 and the natural fiber intermediate layer 5. Depending on the desired moisture diffusion resistance, the chemical fiber outer layers 3 can consist of several knitted layers stacked on top of each other. Likewise, the natural fiber intermediate layer 5 can consist of several woven layers stacked on top of each other, depending on the desired component thickness.

[0033] The flax fibers of the natural fiber intermediate layer 5 could be replaced by other suitable natural fibers. Likewise, the PES fibers of the chemical fiber outer layers 3 could be replaced by other suitable chemical fibers that impede moisture diffusion from the outside to the fiber intermediate layers 5.

[0034] A paint layer 9 can also be applied to the outside of the body outer skin component 1.

[0035] The layers of the body outer skin component 1 are essentially - apart from the paint layer 9, although this can of course also be applied to both sides of the body outer skin component - constructed symmetrically to the center of the body outer skin component 1, so that the body outer skin component 1 does not warp during the manufacturing process and has the same mechanical properties in both bending directions of the component.

[0036] The plastic matrix of the fiber-reinforced plastic is preferably made of epoxy resin and a corresponding hardener.

[0037] The body outer skin component 1 is manufactured using a single prepreg, which comprises both the chemical fiber outer layers 3 and the natural fiber intermediate layer 5. The single prepreg is inserted into the tools of the autoclave process or the compression molding process, and then the body outer skin component 1 is manufactured using the respective process. Alternatively, the body outer skin component 1 can be manufactured using three

[0038] Prepregs are produced, ie two prepregs with the

[0039] Chemical fiber outer layers 3 and a prepreg with the natural fiber intermediate layer 5.

Claims

Patent claims 1 . Body outer skin component made of fiber-reinforced plastic or of a fiber-plastic composite, which has two chemical fiber outer layers (3) comprising a textile fabric consisting of chemical fibers and at least one natural fiber intermediate layer (5) comprising a textile fabric consisting of natural fibers, wherein the natural fiber intermediate layer (5) is arranged between the two natural fiber outer layers (3).

2. Body outer skin component according to claim 1, wherein the chemical fiber outer layers (3) are directly adjacent to the natural fiber intermediate layer (5).

3. Body outer skin component according to claim 1 or 2, wherein the chemical fiber outer layers (3) are formed by a knitted fabric or a woven fabric or a non-woven fabric.

4. Body outer skin component according to claims 1 to 3, wherein the chemical fiber outer layers (3) have a basis weight of 50 g / m 2 up to 450 g / m 2 , especially 100 g / m 2 up to 250 g / m2 , for example 130 g / m 2 , and / or wherein the chemical fiber outer layers (3) are formed from PES fibers.

5. Body outer skin component according to one of claims 1 to 4, wherein the natural fiber intermediate layer (5) is formed from a woven fabric or a scrim.

6. Body outer skin component according to one of claims 1 to 5, wherein the natural fiber intermediate layer (5) has a basis weight of 100 g / m 2 up to 600 g / m 2 , especially 200 g / m 2 up to 400 g / m 2 , for example 300 g / m 2 , and / or wherein the natural fibers of the natural fiber intermediate layer (5) are plant fibers, for example bast fibers, in particular flax fibers (flax, hemp, bamboo, etc.), or seed fibers or leaf fibers.

7. Body outer skin component according to one of claims 1 to 6, wherein the body outer skin component (1) further comprises a paint layer (9) on its outer side.

8. Body outer skin component according to one of claims 1 to 7, wherein a plastic matrix of the fiber-reinforced plastic consists of a thermosetting plastic, in particular based on epoxy resin.

9. Body outer skin component according to one of claims 1 to 8, wherein the two chemical fiber outer layers (3) and the natural fiber intermediate layer (5) are formed from a single prepreg or from one prepreg per layer.

10. Body outer skin component according to one of claims 1 to 9, wherein the body outer skin component (1) is a vehicle roof outer skin or a fender outer skin or a front cover outer skin or a side wall outer skin or a sill panel or a bumper panel.

11. Prepreg for a body outer skin component according to one of claims 1 to 10, consisting of two chemical fiber outer layers (3) comprising a textile fabric consisting of chemical fibers and at least one natural fiber intermediate layer (5) arranged between the chemical fiber outer layers (3) and comprising a textile fabric consisting of natural fibers.

12. A method for producing a body outer skin component (1) according to one of claims 1 to 10 by means of an autoclave process or press molding using a prepreg according to claim 11 or using one prepreg each for the chemical fiber outer layers (3) and the natural fiber intermediate layer (5).

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