DE102015007924A1 - Composite component for a vehicle, in particular a motor vehicle, and method for producing such a composite component - Google Patents

Abstract

The invention relates to a composite component for a vehicle, having a core layer (10) made of a thermoplastic foam and at least one cover layer (12, 14) connected to the core layer (10), which are pressed together, wherein the composite component is in at least a first portion ( 20) to which plastic (40) is injection-molded, is pressed more strongly than in at least one second partial region (22) adjoining the first partial region (20), and a method for producing such a composite component.

Description

The invention relates to a composite component for a vehicle according to the preamble of patent claim 1 and to a method for producing such a composite component according to the preamble of patent claim 6.

Such a composite component for a vehicle, in particular a motor vehicle, and a method for producing such a composite component, for example, already from the DE 10 2006 058 257 A1 to be known as known. The composite component has a core layer, which is formed from a thermoplastic foam. In other words, the core layer is formed as a foam element, which is made of a plastic in the form of a thermoplastic. The composite component further comprises at least one cover layer, which is connected to the core layer. This means that the cover layer is arranged on the core layer, with the core layer and the cover layer at least partially overlapping one another. The core layer and the cover layer are pressed together.

In the context of the method for producing the composite component, the core layer and the cover layer are introduced into a pressing tool and pressed together by means of the pressing tool, wherein the cover layer and the core layer form a composite layer of the composite component. It is possible to form the composite component as a sandwich composite component, so that the composite layer is a sandwich composite. At least one further cover layer is arranged on one side of the core layer facing away from the cover layer and connected to the core layer.

In addition, the reveals DE 10 2005 030 279 A1 a plastic element for wall cladding in vehicles, with a decorative layer, a first layer for thermal protection, a layer which is composed of a high heat resistant and at least partially reversible compliant thermoplastic foam, a second layer for thermal protection, which consists of a nonwoven which consists of a Polypropylene-polyester mixture is formed, and a back injection of plastic.

Typically, the use of sandwich components is generally limited to a pressing process, which limits the possibility of functional integration. Reinforcements and / or attachment elements are usually glued, that is glued to the composite component. Thus, further production processes are necessary, which worsens the economy, especially in large quantities. When spraying plastic on composite components with core layers of a plastic foam, problems may arise due to the low compressive strength of the core layer and the cover layer. Under such a spraying is generally to be understood that the composite component is provided at least in a partial area by injection molding with a plastic, wherein the composite component is back-injected with the plastic and / or injected. In injection molding or plastic injection molding, high pressures of the initially liquid plastic act on the composite component, whereby the risk exists that the core layer is compressed.

As a result, there is no complete seal between the composite component and an injection molding tool, by means of which the composite component is provided with the plastic. As a result, the sprayed material, ie the liquid plastic, flooded the composite component. In addition, in the case of composite components with a visible side and a rear side facing away from the visible side, the risk of the backside injection on the injection molding contour being reflected by deformation of the core layer and the cover layer on the visible side. The visible side is to be understood as meaning such a side of the composite component which, in the finished manufactured state of the vehicle, is visually perceptible by a viewer of the vehicle, in particular by occupants residing in the interior of the vehicle. Here are such a visual page particularly high demands on the feel and the look that can be affected by the injection molding.

The object of the present invention is therefore to further develop a composite component and a method of the type mentioned above such that the composite component can be provided with a plastic in a simple manner without impairing the composite component, in particular with respect to its shape and functionality.

In order to develop a composite component of the aforementioned type such that the composite component can be provided in a particularly simple manner with plastic, without affecting the composite component in terms of its shape and functionality, it is inventively provided that the composite component in at least a first portion stronger than is pressed in at least one adjoining the first portion second portion, wherein molded onto the first portion of plastic. The molding of plastic onto the first subregion is to be understood as meaning that the composite component in the first subregion or the first subregion itself is provided with plastic by injection molding, that is to say as part of an injection molding process. By the Injection molding, the portion is molded with the liquid plastic and / or injected behind.

In injection molding, high pressures and thus high forces from the initially liquid plastic act on the composite component or the partial area. Since, however, the first portion is pressed more strongly than the second portion, the composite component formed, for example, as a sandwich composite component is impaired neither by the pressure during injection molding nor by the temperature occurring during injection molding in its shape and functionality. As a result of the stronger compression in the first subarea than in the second subarea, the composite component, in particular the core layer, has a smaller thickness or wall thickness in the first subarea than in the second subarea. Furthermore, the density of the core formed as a foam core is locally increased by the locally limited, stronger compression in the production of the composite component, resulting in an increase of the mechanical pressure properties of the core layer, that is the thermoplastic resin foam, compared to the less compressed second portion. However, since the composite component is only more strongly compressed locally, the material character of the composite component remains preserved over the entire composite component.

By locally stronger compression of the composite component this can be produced without additional material, cost or time and thereby trained to load, the compressive strength and the compressive stiffness are increased locally, that is, in the first portion, compared to the second portion. As a result, the composite component in the first subregion can endure high pressures and temperatures occurring during injection molding, without the composite component, in particular the core layer, being excessively deformed. As a result, a sufficient seal between the composite component and an injection molding tool, by means of which the plastic is injected onto the first portion, can be ensured, so that the initially liquid plastic does not undesirably flood the composite component. The core layer and the cover layer form a layer composite, in particular a sandwich composite. Due to the locally stronger compression and thus compression of the layer composite, the density of the core layer in the first portion is increased so that the layer composite withstand the pressure occurring during injection molding, so that the spraying can be accomplished harmless.

Preferably, the layer composite is heated and pressed in a heated state. In this case, the core layer can be permanently compressed in a heated state within a certain temperature range and thus locally compressed more strongly without damaging the core layer.

It has proven to be particularly advantageous if a rib or a connecting element is formed by the injection-molded plastic. The rib is, for example, a reinforcing or stiffening rib, by means of which a particularly high rigidity of the composite component can be achieved overall in a weight-saving manner. By means of the connection element, the composite component can be connected to at least one further component of the vehicle. Since the plastic and thus the connecting element formed by the plastic are arranged in the first partial area more compressed compared to the second partial area, and since the composite component, in particular the core layer, has a particularly high compressive strength and compressive rigidity in the first partial area, the further component can be particularly strong and Stably connected to the composite component via the connection element. The connection element is, for example, a connection element such as a clip, that is to say a latching element.

In order to realize particularly advantageous properties, in particular mechanical properties, and thus to make the composite component particularly stress-resistant, it is provided in one embodiment of the invention that the cover layer is formed from a fiber-reinforced plastic. Preferably, the temperature during injection molding, that is the so-called injection molding, far above the melting temperature of the plastic of the cover layer, so that a cohesive connection of the injected plastic, which is injected, for example, to the cover layer, with the cover layer as a result of melting of the thermoplastic portion of the cover layer the injection molding heat can be achieved.

It has been found to be particularly advantageous if the plastic of the cover layer is a thermoplastic. The thermoplastic of the cover layer is a matrix or plastic matrix and in particular thermoplastic matrix in which reinforcing fibers are at least partially embedded. These reinforcing fibers are preferably glass fibers and / or natural fibers and / or carbon fibers or carbon fibers, thereby providing, for example, a particularly advantageous rigidity of the cover layer and thus of the composite component as a whole.

A particularly advantageous embodiment is characterized in that the thermoplastic of the cover layer is polypropylene (PP). The cover layer is for example a nonwoven or formed from a nonwoven fabric and can in particular be formed a hybrid nonwoven fabric. Furthermore, it is conceivable that the cover layer is formed from an organic sheet or a hybrid weave.

It has also been shown to be particularly advantageous if the thermoplastic plastic foam of the core layer is formed from polyethylene terephthalate (PET). In other words, the core layer is preferably a PET foam core whose density and thus mechanical pressure properties can be increased particularly advantageously by the locally stronger pressing.

The bonding of the cover layer to the core layer can be effected by at least one bonding layer, in particular melt layer, arranged between the core layer and the cover layer. The melt layer is formed, for example, by at least one plastic. The at least one plastic may be one of the plastics of the core layer and / or the cover layer or else an additionally provided plastic. Alternatively, it is conceivable that the bonding layer arranged between the core layer and the cover layer is formed by an adhesive, in particular a reactive adhesive, by which a layer, which is different from the cover layer and the core layer, is additionally provided in the form of an adhesive layer.

As an alternative to the thermal bonding of the layers of the multilayer composite for producing the semifinished product, the layers of the multilayer composite can also be joined together mechanically, in particular by needling. This is particularly recommended when the cover layer comprises a batt and / or non-woven fabric; Furthermore, the cover layer advantageously also comprises a melt layer of a thermoplastic. The batt and core layer are then joined by piercing at least one barbed needle into the core layer and the batt followed by the needle out of the core layer and the batt. In this case, when inserting and / or pulling out the needle, one or more fibers of the batt and / or fiber web are hooked to the barb and mechanically anchored to the core layer during insertion and / or removal of the needle. Alternatively or additionally, the needle may first pierce the batt / nonwoven fabric and only then the core layer, so that the needle pushes fibers through the core layer during piercing, which causes a mechanical anchoring of the core layer with the batt / nonwoven fabric.

In order to further develop a method of the type mentioned above such that the composite component can be provided with plastic in a particularly simple manner without impairing the composite component in terms of its shape and functionality, it is provided according to the invention that the composite component stronger in at least a first portion is pressed in at least one adjacent to the first portion second portion, whereupon a plastic is molded onto the first portion. Advantageous embodiments of the composite component according to the invention are to be regarded as advantageous embodiments of the method according to the invention and vice versa. The invention is thus based on the idea of compressing the composite component locally, that is to say in the first subarea more strongly than in the second subarea, thereby increasing the compressive strength and compressive stiffness of the core layer and in particular of the composite component as a whole in the first subarea relative to the second subarea realize. As a result of this locally increased pressure rigidity and compressive strength, the first subarea can be provided with plastic by injection molding or plastic injection molding without the pressures and temperatures prevailing during injection molding leading to undesired damage and deformations of the composite component.

In an advantageous embodiment of the method according to the invention, a cover layer of a fiber-reinforced plastic is used as the cover layer, wherein at least the core layer during pressing has a temperature which corresponds at least almost to the melting temperature of the plastic of the cover layer. This makes it possible to realize a particularly advantageous increase in the density and thus the mechanical compressive strength and compressive rigidity of the core layer. It has been found to be particularly advantageous if the temperature is in a range of 160 degrees Celsius to 250 degrees Celsius. Straight PET is in a softened state at temperatures above 140 ° C and can thus be plastically deformed. Melting only starts when the melting point reaches 250 ° C, while PP melts at 160 ° C. This combination of materials is thus particularly advantageous because between 160 ° C and 250 ° C, the thermoplastic of the cover layer is melted and the core is plastically deformable without the foam structure is destroyed. This results in a large usable temperature range for the manufacturing process.

Finally, it has proven to be particularly advantageous if the composite component is pressed by means of the tool, by means of which the plastic is injected onto the portion. In other words, the composite component is pressed by means of the same tool and provided with the plastic. As the tool thus formed as a press and injection mold tool is used so that in a single tool, the composite component pressed and with Plastic can be injected. The pressing tool is, for example, a forming tool, by means of which the composite component is formed during compression. Alternatively, it is possible that the composite component after pressing and the possible forming of a first tool removed from the mold and introduced into a different from the first tool, the second tool. The second tool is, for example, an injection molding tool, by means of which the first portion is molded with plastic.

The first partial area, which is more compressed or compressed than the second partial area, acts as a sealing groove during injection molding, so that undesired over-spraying can be avoided which would contaminate the composite component. Furthermore, due to the increased density undesirable marks on a visible side of the composite component can be prevented. Such markings are, for example, unwanted deformations and shiny spots on the visible side, which is visually perceptible in the finished manufactured state of the vehicle. These problems can be avoided by the method according to the invention. Thus, by means of the method according to the invention, a clean, overspray-free application or injection-in-place of the composite component designed as a sandwich composite component can be achieved, without excessive markings on a surface, in particular the visible side, of the composite component.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; these show in:

1 1, a schematic sectional view through a composite component according to a first embodiment for a vehicle, with a core layer of a thermoplastic foam and at least one core layer connected to the cover layer, which are pressed together, wherein the composite component in at least a first portion, to which plastic is injection-molded is pressed more strongly than in at least one second partial area adjoining the first partial area;

2a -D each a schematic side view of a tool at respective steps of a method for producing the composite component;

3 a detail of a schematic sectional view through the composite component according to a second embodiment;

4 1, a schematic sectional view through the composite component according to a third embodiment;

5 1, a schematic sectional view through the composite component according to a fourth embodiment; and

6 a fragmentary sectional view through the composite component according to a fifth embodiment.

In the figures, the same or functionally identical elements are provided with the same reference numerals.

1 shows a schematic sectional view of a composite component according to a first embodiment of a vehicle, in particular a motor vehicle such as a passenger car. The composite component has a core layer 10 from a thermoplastic foam on. Preferably, the thermoplastic resin foam is formed from polyethylene terephthalate (PET), so that the core layer 10 a PET foam core is. Furthermore, the composite component comprises a first cover layer 12 which is on a first side of the core layer 10 is arranged. In addition, the composite component comprises a second cover layer 14 which on a side facing away from the first side, the second side of the core layer 10 is arranged. The respective cover layer 12 and 14 is preferably formed from a fiber-reinforced plastic and thus comprises a plastic matrix, preferably of polypropylene (PP), as well as reinforcing fibers, which are embedded in the plastic matrix. For example, the respective cover layer 12 respectively 14 formed as a nonwoven fabric.

Present are between the core layer 10 and the respective cover layer 12 respectively 14 further intermediate layers 16 and 18 arranged, wherein through the intermediate layers 16 and 18 For example, respective binding layers are formed. Over the respective bonding layer is the core layer 10 with the respective cover layer 12 respectively 14 connected. For example, the respective intermediate layer 16 respectively 18 made of polypropylene, wherein the respective intermediate layer 16 respectively 18 may be formed as a polypropylene film. The core layer 10 , the top layers 12 and 14 as well as the intermediate layers 16 and 18 are respective layers which form a layer composite in the form of a sandwich composite. Thus, the composite component is formed as a sandwich composite component. The layer composite is first provided, for example, as semifinished product and heated, whereby, for example, the intermediate layers 16 and 18 be melted. This will make the cover layers 12 and 14 with the core layer 10 connected.

For example, during heating, the semi-finished product is already in a tool. Alternatively, it is conceivable to introduce the semi-finished product after heating in a tool. By means of the tool, the semifinished product, that is to say the layer composite, is preferably pressed in a heated state. This will make the cover layers 12 and 14 with the core layer 10 pressed.

Out 1 it can be seen that the composite component at least a first portion 20 in which the composite component stronger than in the first portion 20 adjacent, second sections 22 is compressed. Further, to the first subarea 20 molded plastic, through which in this case a rib 24 is formed. Out 1 it can be seen that the core layer 10 and in the present case, the composite layer as a whole by the opposite to the second partial regions 22 stronger compression in the first section 20 have a smaller thickness, wherein the core layer 10 towards the second subareas 22 in the first subarea 20 has a higher density. This shows the core layer 10 and thus the composite component as a whole with respect to the second partial areas 22 and the first subarea 20 a higher compressive strength and compressive stiffness. The plastic from which the rib 24 is formed is, by means of an injection molding process to the first portion 20 molded. In injection molding, high pressures and temperatures affect the first section 20 , where the first subarea 20 or the composite component in the first subarea 20 These high pressures and temperatures due to the locally increased compressive strength and compressive stiffness can endure damage. The opposite to the second subareas 22 more compressed first section 20 acts as one in 1 particularly schematically shown sealing groove 26 so that a clean and splash-free molding of the plastic of the rib 24 is feasible.

In other words, it is envisaged that during compression and any associated shaping of the layer composite, this layer composite will be pressed more strongly locally at points which are to be injection-molded later with a plastic than at other points. As a result, the density of the core layer formed as a foam core increases at the locally more compressed points 10 and the degree of consolidation of the outer layers 12 and 14 , In the case of subsequent injection molding, the sprayed material, that is to say the initially liquid plastic, is less strongly pressed into the layer composite, since the more compressed areas or partial areas act like a sealing groove. A clean and injection-free molding of elements such as reinforcing ribs and connecting elements is made possible. Furthermore, the impression of the spray contour on a possible visible side 28 prevents the composite component. In other words, it is preferably provided that the composite component on one of the visible side 28 facing away back 30 is provided with the plastic.

2a FIG. 3 d show, in respective side views, a tool by means of which a method for producing the composite component is carried out. The tool includes two mold halves 32 and 34 which are arranged opposite and movable toward and away from each other. 2a shows a first step of the process. First, the above-mentioned, a semifinished semifinished product is heated until the thermoplastics of the outer layers 12 and 14 are transferred to the plastic state. In this case, the semi-finished already in the tool, that is, between the tool halves 32 and 34 be arranged. Alternatively, it is conceivable to introduce the layer composite after heating in the tool, while the tool halves 32 and 34 are open. The tool is on the one hand a press in the form of a hot press, since the layer composite is pressed in the heated state by means of the tool and thereby, for example, deformed. On the other hand, the tool is an injection mold, as one of the tool halves 32 and 34 and in this case the first tool half 32 via an injection molding device 36 has or has an injection molding machine. By way of example, the underside of the laminate forms the visible side 28 , which is why the upper tool half 32 with the injection molding device 36 is provided and has the necessary geometry for locally reinforced pressing. This geometry is presently a projection 38 the tool half 32 ,

At an in 2 B shown second step, the tool halves 32 and 34 moved towards each other, that is closed, while the composite layer between the tool halves 32 and 34 is arranged. As a result, the layer composite is pressed and reshaped. Because the tool half 32 the lead 38 has, the layer composite in the first subregion 20 in comparison to the adjacent second subareas 22 stronger pressed. In other words, the lead ensures 38 for a locally reinforced pressing of the layer composite. Show 2a -D a possible geometry or shape of the projection 38 , being out 3 to 6 other, other geometries or shapes are recognizable, by means of which a locally reinforced pressing of the layer composite can be realized. 2c shows a third step of the method, wherein at still closed mold halves 32 and 34 of the formed as a forming and injection molding tool in the first part 20 , the opposite of the subareas 22 has a stronger compression and consolidation, the in 2c and 2d With 40 designated plastic is injected onto the layer composite. By means of the plastic 40 will be out 2d recognizable rib 24 produced. The injection molding process step can also be carried out independently of the forming process if the forming process is not carried out in a combined hot-press injection molding machine but in an upstream pressing tool. In other words, it is possible, for example, first to press the layer composite by means of a first tool and in the first sub-area 20 towards the second subareas 22 stronger to be pressed. After pressing, the layer composite is demolded, for example, from the first tool and placed in a second tool, by means of which finally the first portion 20 is sprayed with an initially liquid plastic. It is also conceivable alternatively, to let the injection in the injection mold, which reduces the expenditure on equipment and shortens the process time.

The tool half 32 has at least one feed channel 42 on, over which the plastic 40 introduced in the first liquid state and the first part 20 is supplied. In other words, the first subarea 20 over the feed channel 42 molded. Under this injection molding is to be understood that the first portion 20 with the plastic 40 provided, that is molded and / or injected behind. Is the first liquid plastic 40 solidified and therefore dimensionally stable, so the tool halves 32 and 34 at a in 2d be opened fourth step of the method, so that the composite member with the rib 24 can be removed from the mold. Alternatively or additionally, by means of the method, other elements such as, for example, attachment elements can be injection-molded onto the composite component, so that the composite component can be connected to at least one further component of the vehicle, for example via the attachment elements.

3 shows the composite component according to a second embodiment, wherein the rib 24 in contrast to the first embodiment has a different geometry. Also the first section 20 has a different geometry from the first embodiment. Depending on the design of the first portion designed as a compression region 20 can have a rib mark on a surface 44 on the visible side 28 , the rib adhesion, the warpage and the sealing function are influenced.

Instead of PET can be used for the core layer 10 a different thermoplastic material may be used, which, however, preferably has a melting temperature which is above the melting temperature of the respective plastic of the outer layers 12 and 14 , in particular polypropylene, lies.

4 shows a third embodiment, in which in turn other geometries of the rib 24 and the first subarea 20 as provided in the first two embodiments. 5 shows a fourth embodiment of the composite component, wherein the geometries of the rib 24 and the first subarea 20 different from the previous geometries. Finally shows 6 the composite component according to a fifth embodiment, in which in turn other geometries of the rib 24 and the first subarea 20 are provided.

Due to the locally reinforced pressing, the properties of the core layer can be determined locally 10 to be changed. In particular, in the injection molding shows that high foam densities are good for low marks. For example, it may be useful to locally increase the foam density of a component in order to be able to spray injection molding material at this point or at this point, without resulting in excessive damage and marks. Alternatively or in addition to the locally higher compression, the compressive rigidity can be realized locally by reinforcements or inserts.

Based on 1 to 6 Thus, a method has been explained by means of which sandwich composite components can be molded with thermoplastic foam core and at least one cover layer of fiber-reinforced textile fabrics with thermoplastic matrix with plastic. As a result, a functional integration of light sandwich composite components can be represented, since in particular functional elements such as ribs and connecting elements can be molded onto the layer composite. In this case, further assembly processes such as bonding can be avoided because functional elements do not have to be attached to the layer composite in additional, subsequent to the pressing steps. The locally more compressed first section 20 acts as a sealing groove during injection molding, whereby a clean and overspray-free molding of plastic or elements to be produced from it is made possible. If the parameters are suitable, there may also be marks on the visible side 28 the composite component can be safely avoided.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006058257 A1 [0002]
• DE 102005030279 A1 [0004]

Claims (10)

Composite component for a vehicle, having a core layer ( 10 ) of a thermoplastic foam and at least one with the core layer ( 10 ) associated cover layer ( 12 . 14 ), which are pressed together, characterized in that the composite component in at least a first portion ( 20 ), to which plastic ( 40 ) is stronger than in at least one of the first portion ( 20 ) adjacent second subarea ( 22 ) is compressed. Composite component according to claim 1, characterized in that by the molded plastic a rib ( 24 ) or a connection element is formed. Composite component according to claim 1 or 2, characterized in that the cover layer ( 12 . 14 ) is formed from a fiber-reinforced plastic, wherein the plastic of the cover layer ( 12 . 14 ) is a thermoplastic, preferably polypropylene. Composite component according to one of the preceding claims, characterized in that the thermoplastic plastic foam of polyethylene terephthalate (PET) is formed. Composite component according to one of the preceding claims, characterized in that between core layer ( 10 ) and cover layer ( 12 . 14 ) An adhesion-promoting layer is arranged. Method for producing a composite component for a vehicle, in which a core layer ( 10 ) of a thermoplastic foam with at least one cover layer ( 12 . 14 ) and pressed by means of a tool, characterized in that the composite component in at least a first portion ( 20 ) stronger than in at least one of the first subregion ( 20 ) adjacent second subarea ( 22 ) is pressed, whereupon a plastic ( 40 ) to the first subarea ( 20 ) is injected. Method according to claim 6, characterized in that as the cover layer ( 12 . 14 ) a cover layer ( 12 . 14 ) is used from a fiber-reinforced plastic, wherein at least the core layer ( 10 ) has a temperature during pressing, which at least almost the processing temperature of the plastic of the cover layer ( 12 . 14 ) corresponds. A method according to claim 7, characterized in that the temperature is in a range of 160 degrees Celsius to 250 degrees Celsius. Method according to one of the preceding claims, characterized in that the composite component is pressed by means of the tool, by means of which the plastic ( 40 ) to the first subarea ( 20 ) is injected. Method according to one of the preceding claims, characterized in that the cover layer ( 12 . 14 ) comprises a batt and / or non-woven fabric, the batt and the core layer ( 10 ) by piercing at least one barbed needle into the core layer ( 10 ) and the batt and subsequent removal of the needle from the core layer ( 10 ) and the batt, wherein when piercing and / or pulling out the needle, one or more fibers of the batt and / or non-woven fabric hooks with the barb and when inserting and / or removing the needle mechanically with the core layer ( 10 ).

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