Body outer skin component

Abstract

Body outer skin component made of fiber-reinforced plastic or of a fiber-plastic composite comprising several fiber layers with at least one fiber interlayer (5), comprising a textile fabric consisting of natural fibers, comprising a fiber outer layer (3), comprising a textile fabric consisting of chemical fibers and comprising a fiber middle layer (7), comprising a knitted fabric made of chemical fiber, wherein the fiber interlayer (5) is formed from a non-woven or woven fabric.

Description

[0001] The invention relates to an outer body panel component for a motor vehicle body, for example a passenger car or a commercial vehicle.

[0002] The body of a passenger car is typically constructed using a self-supporting monocoque design. Most often, the body is made of steel or aluminum, or a combination of these materials. Sometimes, an outer body panel is also made of a fiber-reinforced plastic composite, for example, with carbon fibers or glass fibers.

[0003] It is also known to produce fiber-reinforced plastics using natural fibers. Natural fibers are usually hygroscopic, meaning they can absorb moisture over time, even within a fiber-reinforced plastic composite. Natural fibers are made from a renewable resource and have the advantage of generally having a better CO2 balance compared to synthetic fibers.

[0004] Furthermore, WO 2013 / 127 419 A1 specifies a fiber-reinforced plastic component produced by hot pressing, i.e. an organosheet, with cover layers and alternating fiber layers and damping layers.

[0005] Furthermore, DE 10 2013 002 364 A1 relates to a fiber-reinforced visible automotive component with a paintable Class A surface, in which reinforcing fibers are more easily visible and which is mechanically more resilient.

[0006] The EP 2 410 576 A2 D3 relates to a composite component for use as an outer skin component of a vehicle with a solar-active layer.

[0007] Furthermore, WO 01 / 68 353 A1 is directed to a process for the production of fiber-reinforced plastic components from dry fiber composite semi-finished products using an injection process.

[0008] DE 10 2012 105 500 A1 shows a fiber composite component, which is at least partially based on bio-based polymer fibers, with a multi-layered structure, which can also be used in vehicle construction.

[0009] Furthermore, EP 2 664 445 A1 relates to a multi-layer composite structure made of fiber-reinforced thermoplastic material as a visible structure for a vehicle, such as a hood.

[0010] Finally, DE 601 22 449 T2 discloses a composite laminate consisting of a core and two outer layers for sporting goods, wherein the fibers of the outer layers are made of high-performance fibers and the core is made of fibers with low mechanical properties.

[0011] The object of the present invention is to create a body outer skin component made of a fiber-reinforced plastic composite, wherein the body outer skin component is manufactured more sustainably and has a consistent surface quality over time, for example a consistent optical surface quality.

[0012] This problem is solved by a body outer skin component that has the combination of features of claim 1. Advantageous further developments are mentioned in the dependent claims.

[0013] According to the invention, a body outer skin component is made of fiber-reinforced plastic or a fiber-reinforced plastic composite. The fiber-reinforced plastic composite has several fiber layers. An intermediate fiber layer has a textile surface structure consisting of natural fibers, and an outer fiber layer has a textile surface structure consisting of synthetic fibers.

[0014] The outer fiber layer, with its textile fabric consisting of synthetic fibers, works in conjunction with a polymer matrix of the fiber-reinforced composite to inhibit moisture diffusion, thus reducing the amount of moisture reaching the interlayer from the outside. The synthetic fibers are not hygroscopic, or at least less hygroscopic than natural fibers. This prevents, or at least limits, the absorption of moisture by the hygroscopic natural fibers in the interlayer. Moisture absorption by the natural fibers in the interlayer can cause them to swell, i.e., increase in volume. This swelling, in turn, affects the surface of the body panel, altering its texture. The surface of the body panel becomes more wavy, i.e., less smooth or even.Changes to the surface of the body panel are visible and may be perceived by a user as aging and thus a loss of quality. However, surface changes can also have other functional disadvantages. For example, they can promote the adhesion of dirt. Similarly, surface changes can be detrimental to any function of the body panel that requires a consistent or smooth surface. The use of natural fibers results in a better CO2 footprint for the body panel during production. To further improve the CO2 footprint, the synthetic fibers can be made from recycled materials.

[0015] The body panel component can also be a body add-on part. The body panel component can be screwed, riveted, clipped, and / or bonded to the vehicle body.

[0016] Preferably, the fiber interlayer is directly adjacent to the outer fiber layer, i.e., no further fiber layer is arranged between the outer fiber layer and the fiber interlayer.

[0017] The outer fiber layer can be arranged on an outward-facing side of the body panel. The outer fiber layer can also be arranged on an inward-facing side of the body panel. Furthermore, an outer fiber layer made of synthetic fibers can be formed on both the outward-facing and the inward-facing side of the body panel.

[0018] Furthermore, several interlayer fibers made of natural fibers can be arranged between the outer fiber layers.

[0019] The body outer skin component can be manufactured using the so-called RTM process, i.e., by means of the resin injection process (Resin Transfer Moulding).

[0020] According to the invention, the body outer skin component further has a fiber middle layer which comprises a textile surface structure made of chemical fiber.

[0021] The fiber core layer serves in particular as a flow aid for a resin of the plastic matrix during a manufacturing process of the fiber-plastic composite or the body outer skin component.

[0022] According to the invention, the fiber core layer is formed by a knitted fabric.

[0023] A knitted fabric allows the resin to flow particularly well.

[0024] A knitted fabric can be produced particularly well with a synthetic fiber, especially a thin synthetic fiber, so synthetic fibers, such as PES, are preferable to natural fibers for knitted fabrics. A thinner fiber, in turn, allows for a thinner core layer, which is advantageous in terms of weight and component thickness. With a knitted fabric made of natural fibers, thicker fibers would have to be used.

[0025] Furthermore, the fiber interlayer is formed from a non-woven fabric or woven material. A non-woven fabric is advantageous in that it can be produced with any fiber orientation. This can reduce waste compared to a woven fabric.

[0026] The fiber interlayer can have a fiber orientation of +45° / -45°.

[0027] A fiber orientation offset by 90° enables almost isotropic behavior of the fiber interlayer or body panel component. If anisotropic material or component behavior is desired, other fiber orientations are also possible.

[0028] The outer fiber layer can have a fiber orientation of 0° / 90°.

[0029] However, a unidirectional alignment of the fibers in the outer fiber layer is also possible.

[0030] Natural fibers can be plant fibers, such as bast fibers, especially flax, hemp, or bamboo, or seed fibers or leaf fibers. Flax fibers are particularly preferred due to their high availability. Furthermore, flax fibers have a particularly homogeneous structure and are cost-effective.

[0031] Chemical fibers can be organic or inorganic. Organic chemical fibers include synthetic polymers. Polyester (PES) is a particularly popular choice for chemical fibers. Polyester absorbs very little moisture. High-quality polyester chemical fibers are relatively inexpensive.

[0032] A layer of paint, in particular a clear coat, is preferably applied to the outside of the body skin component.

[0033] The paint layer can also reduce the diffusion of moisture into the outer body panel.

[0034] The layers of the body outer skin component are preferably structured symmetrically to the fiber core layer.

[0035] A plastic matrix of the fiber-reinforced plastic is advantageously a thermosetting plastic produced with a liquid resin, in particular an epoxy resin, and a suitable hardener.

[0036] The body outer skin component can be a vehicle roof outer skin, a fender outer skin, a front cover outer skin, a side wall outer skin, a sill panel, or a bumper panel.

[0037] The aforementioned features can be combined in any way possible and where appropriate.

[0038] A brief description of the character follows. Fig. Figure 1 is a schematic sectional view of a body outer skin component according to an embodiment of the present invention.

[0039] The following is with reference to Fig. 1 an embodiment of the present invention is explained.

[0040] Fig.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-reinforced plastic composite according to the embodiment of the present invention. The fiber-reinforced plastic composite is produced by an RTM process. The section shows the individual layers of the fiber-reinforced plastic composite. The layers of the fiber-reinforced plastic composite differ with respect to the fiber layers, i.e., the fiber-reinforced plastic composite has several fiber layers, all of which are embedded in the same plastic matrix. The fiber-reinforced plastic composite has an outer fiber layer 3 and an inner fiber layer 3. The inner fiber layer 3 is thus on an outer surface of the body outer skin component 1. The outer fiber layer 3 is thus on an inner surface of the body outer skin component 1.Adjacent to both the outer fiber layer 3 and the inner fiber layer 3, an intermediate fiber layer 5 is arranged. The outer fiber layers 3 are formed by a woven fabric of PES fibers. The intermediate fiber layers 5 are formed by a non-woven fabric of hemp fibers.

[0041] A fiber core layer 7 is arranged in the center of the fiber-reinforced plastic composite. This fiber core layer consists of a knitted fabric made of PES fibers and serves as a flow aid in the RTM manufacturing process. The fiber core layer allows the liquid resin to be distributed more effectively within the component during the manufacturing process.

[0042] The outer fiber layers 3, made of PES fibers, inhibit moisture diffusion, thus reducing the amount of moisture reaching the intermediate fiber layers 5 from the outside. This prevents, or at least limits, the absorption of moisture by the hygroscopic flax fibers of the intermediate fiber layers 5 during operation of the vehicle's body panel 1. Moisture absorption by the flax fibers would cause the intermediate fiber layers 5 to swell, which would be visible to a user of the vehicle on the surface of the body panel 1. This would result in a visible change to the surface of the body panel 1, which a user might perceive as aging and thus as a loss of quality. Furthermore, dirt could then accumulate more easily.

[0043] There is no further fiber layer between the outer fiber layers 3 and the intermediate fiber layers 5, nor between the intermediate fiber layers 5 and the core fiber layer 7. However, the outer fiber layers 3 can consist of several layers of woven fabric made of PES fibers. Similarly, the intermediate fiber layers 5 can consist of several layers of non-woven fabric made of flax fibers.

[0044] The fiber interlayers 5 have a fiber orientation of +45° / -45°. The outer fiber layers 3 have a fiber orientation of 0° / 90°. Overall, this gives the body outer skin component 1 the most isotropic behavior possible.

[0045] The flax fibers of the fiber interlayers 5 could be replaced by other suitable natural fibers. Likewise, the PES fibers of the outer fiber layers 3 could be replaced by other suitable synthetic fibers that impede moisture diffusion from the outside to the fiber interlayers 5.

[0046] Furthermore, a coating layer 9, in particular a clear coat layer, is applied to the outer surface of the body panel 1. In the case of a clear coat layer, the fabric structure of the fiber outer layer 3 is visible on the body panel 1.

[0047] The layers of the body outer skin component 1 are essentially - apart from the paint layer 9 - symmetrical to the center of the body outer skin component 1, so that the component does not warp during the manufacturing process and has the same mechanical properties in both bending directions of the component.

[0048] The plastic matrix of the fiber-reinforced plastic is made of epoxy resin and a corresponding hardener.

[0049] The fiber interlayers 5 advantageously have a basis weight of 200 gsm to 600 gsm, particularly preferably 300 gsm. The fiber outer layers 3 preferably have a basis weight of 100 gsm to 130 gsm, particularly preferably 130 gsm. The fiber core layer advantageously has a basis weight of 100 gsm to 400 gsm, particularly preferably 130 gsm. The unit gsm corresponds to the unit g / m². 2 .

Claims

[1] Body outer skin component made of fiber-reinforced plastic or of a fiber-plastic composite comprising several fiber layers with at least one fiber interlayer (5) comprising a textile fabric consisting of natural fibers, comprising a fiber outer layer (3) comprising a textile fabric consisting of man-made fibers and comprising a fiber middle layer (7) comprising a knitted fabric made of man-made fiber, wherein the fiber interlayer (5) is formed from a non-woven or woven fabric. [2] Body outer skin component according to claim 1, wherein the fiber intermediate layer (5) is particularly directly connected to the fiber outer layer (3). [3] Body outer skin component according to one of claims 1 or 2, wherein the fiber orientation of the fiber interlayer is +45° / -45°. [4] Body outer skin component according to one of claims 1 to 3, wherein the fiber outer layer (5) is formed from a woven fabric or nonwoven fabric, and wherein the fiber orientation is in particular 0° / 90°. [5] Body outer skin component according to one of claims 1 to 4, wherein the natural fibers are plant fibers, for example bast fibers, in particular flax fibers, or seed fibers or leaf fibers. [6] Body outer skin component according to one of claims 1 to 5, wherein the body outer skin component (1) further comprises a paint layer (9), in particular a clear coat layer, on its outer surface. [7] Body outer skin component according to one of claims 1 to 6, wherein a plastic matrix of the fiber-reinforced plastic consists of a thermosetting plastic, in particular based on epoxy resin. [8] Body outer skin component according to any one of claims 1 to 7, 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 trim or a bumper trim.

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