DE102011005343A1 - Interior fitting for vehicles - Google Patents

Abstract

Interior part for a vehicle, in particular a motor vehicle, comprising a carrier layer and a decorative layer and a haptic arranged between the carrier layer and the decorative layer, and being formed from a foam system from at least one polyurethane foam and the foam system being a low-energy foam system, and a Method for producing such an interior part.

Description

Technical area

The invention relates to an interior trim part for a vehicle, in particular a motor vehicle, comprising a carrier layer of a rigid material and a decorative layer, and arranged between the carrier layer and the decorative layer haptic layer of a foam system and a method for producing such an interior trim part.

State of the art

In particular, interior components such as door panels or dashboards for motor vehicles of the upper middle class or the upper class have traditionally a layer structure, in which between a support layer, which is intended to guarantee the mechanical stability and is suitable for installation or cultivation of additional components, and a decor at which may be, for example, a real leather decor, a haptic layer is arranged.

The DE 198 54 246 A1 discloses such a component in which a haptic layer in the form of a spacer fabric or a nonwoven material is arranged between a rigid support and a decor. The individual layers are connected to each other via adhesive layers.

The DE 10 2009 004 612 A1 As the state of the art, vehicle parts are called genuine leather decors, which are inserted into a foaming tool and backfoamed. When Hinterschäumen such decorations, there is the problem that the inserted within the foam tool. Decors must be positioned accurately and possibly for positioning several leather parts to each other or relative to the foam tool they must be laminated onto a molded skin. To avoid this complex process step, the document proposes to fix the decor via vacuum nozzles relative to the tool.

The known in the art foam backing of components, d. H. the introduction of a foam layer between the spaced apart in a tool decor layer and carrier layer, or alternatively, an alternative method in which in an open mold a foam is introduced and subsequently the tool is closed, are with significant pressure loads with foam pressures or Mold inner pressures of significantly greater than 1 bar (usually between 2-5 bar) connected to the tool and the decorative layer, for which reason the aforementioned measures for determining the decor relative to the foam tool are required and there are restrictions on the selection of the use decorative layers , A disadvantage of the previously known methods also that due to the relatively high pressures in the tool partitions in the field of view of the decorative layer are not possible. In particular, in the case of decorative materials which have openings, foam openings or penetrations may occur, so that when such decorative materials are used, a cost-intensive sealing of the opening areas must be carried out before the foam layer is introduced.

At the same time, the known foaming processes for the production of interior trim parts for vehicles with a foam layer as a haptic layer require correspondingly complex tools with an elaborate seal to prevent foam breakthroughs at the component edges.

Since conventional methods require sufficient flow of the foam material to form the foam layer through a limited number of injection points, the interior trim components produced by these methods are simultaneously limited in the minimum thickness of the haptic layer formed as a foam layer.

Description of the invention

An object of the present invention is to make interior components such that a foam layer can be used as a haptic without the disadvantages associated with backfoaming in the production of such components must be taken into account and without limitations in the ability to adjust the feel of the Components exist. At the same time, the method is intended to ensure that components with virtually any decorative or carrier layers can be provided with a foam system as a haptic layer, in particular lightweight and / or functional components.

The object is achieved with components according to claim 1 and the method for producing such components according to claim 8. Advantageous embodiments follow from the subclaims and the described preferred embodiments.

The component according to the invention is an interior trim part for a vehicle, in particular a motor vehicle, having a carrier layer of a preferably rigid or plastic (ie, not elastically deformable) material and a decorative layer. Between the carrier layer and the decorative layer is a haptic layer arranged, wherein the haptic layer is a foam layer, which consists of a low-energy foam system with at least one polyurethane foam.

The low-energy foam system may be a one-component system (1K) that is preferably physically foamed, but it is preferably a two-component (2K) system in which the foam structure is at least chemically reacted one of the system forming components, for example, using water as a blowing agent, which reacts with the component to form carbon dioxide is generated.

In the latter case, the foam system comprises at least a first component of a suitable polyol, for example a polyether polyol or a polyester polyol, preferably a long-chain polyol, and a second component of a suitable isocyanate.

The isocyanate may, for example, be a so-called MDI (diphenylmethane diisocyanate). Conceivable, of course, other isocyanates, such as polymer diphenylmethane diisocyanate (PDMA), toluene diisocyanate (TDI), naphthylene diisocyanate (NDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) or 4,4'-diisocyanatodicyclohexylmethane (H12MDI).

The first and / or the second component can be further additives, such. As hardener, propellant, reaction accelerator or reaction retarder can be added to influence the reaction process or the properties of the foam system generated targeted.

A low-energy foam system is essentially defined by the foam foam, which is much lower than in the previously known foaming process for the production of interior trim parts for vehicles.

Cavity pressure. The resulting cavity pressure in low-energy foam systems is less than 1 bar, preferably in the range from 0.02 to 0.5 bar, most preferably in the range from 0.05 to 0.25 bar.

Particularly preferably, the low-energy foam system is a foam system applied in a low-pressure process. This has the advantage, in comparison to the methods known from the prior art, inter alia, that a displacement of parts of the decorative layer does not take place and, for example, tool partitions can be introduced in the visible range of the decorative layer, without these having a negative effect on the appearance due to the foaming process, especially postponed.

In particular, the low-energy foam system is a mixture of the components in a pasty state of aggregation, d. H. to a in a thick to thixotropic state, applied to the decorative layer foam system. In particular, the state of aggregation is chosen such that the foam system does not cover any distance after application or application, ie. H. no longer flowing.

With particular preference, the foam system is a foam system which crosslinks at room temperature (25 ° C.). Alternatively, to set a desired reaction rate, the temperature at which the foam system is applied to the decorative layer can also be selected to be higher.

• • Die Reaktionszeit des Schaumsystems zur vollständigen chemischen Reaktion nach dem Vermischen der ersten und der zweiten Komponente beträgt zwischen 5 und 100 Sekunden, bevorzugt zwischen 15 und 50 Sekunden.
• • Die sich anschließende Aufschäumzeit zur vollständigen Expansion des Schaumsystems beträgt zwischen 15 und 180 Sekunden.
• • Die sich an die Aufschäumzeit anschließende sogenannte Klebefreizeit.

It has proven to be advantageous if the low-energy foam system has the following behavior after application to the decorative layer:

• The reaction time of the foam system for the complete chemical reaction after mixing the first and the second component is between 5 and 100 seconds, preferably between 15 and 50 seconds.
• • The subsequent foaming time for complete expansion of the foam system is between 15 and 180 seconds.
• • The so-called glue-free time following the foaming time.

The density of the foam layer produced is in the range of 5 to 100 kg / m ³ .

The thickness of the haptic layer produced is from 0.1 to 15 mm, preferably from 1 to 8 mm, very particularly preferably from 2 to 5 mm.

The decorative layer used to produce a component according to the invention may be a film made of a polymer material, a skin made of a leather or a leather-like material, or a textile layer, such as a knitted fabric, woven fabric, knitted fabric or other semi-finished product of fibers or threads natural and / or synthetic materials, act.

In a preferred embodiment, the decorative layer is preformed in an upstream process step and has a contour of the vehicle occupant facing decorative side (visible side), which largely already corresponds to the required for installation in the vehicle outer contour. The upstream process may be for example, a deep drawing or high pressure forming or any other suitable forming process. Furthermore, the production of a Nähkleides of several pieces of leather or otherwise joining together of segments of the decorative material to form a contoured decorative layer for the present invention is suitable.

The decorative layer can be provided on its visible side with a grain or other profiling. The following method steps can advantageously preclude damage to the profiling.

The decorative layer preferably has openings. Whereby, for example, the openings may be perforations or recesses with a small opening cross-section. Such perforations are usually incorporated in decorative layers in order to arrange functional elements, for example to allow lighting effects or to define a specific crack behavior of a region of the decorative layer, when an airbag is arranged behind the latter. Furthermore, textile layers often have a pattern in which openings are present between the fibers or threads. If the decorative layer is a leather layer, the decorative layer is often constructed as a sewing dress made of a plurality of stitched leather parts. In the area of the seams system-related openings are present.

The carrier layer is a layer of a preferably rigid material, for example of PP or ABS or another suitable plastic, produced, for example, in an injection molding process. The material used may also be a fiber-reinforced plastic. Alternatively, the carrier may be a compressed fiber mat consisting essentially of natural and / or synthetic fibers (polymer fibers, glass fibers, carbon fibers, or the like) and may optionally contain a matrix material of natural or synthetic raw materials.

Insofar as the carrier layer is later used to attach the component to a further, rigid layer or to position it adjacent to it, the carrier layer may also be a film or a layer of a flexible material.

In an alternative embodiment, the carrier layer can be used to determine the surface geometry of the foam layer, without a lasting connection between the foam layer and the carrier layer is formed. In this case, the support layer is at least as long fixed relative to the decorative layer until the foam layer is dimensionally stable. Subsequently, the carrier layer used in the production is removed and the composite of decorative layer and haptic layer can be connected to any other as a carrier layer. This may preferably be a body part of a vehicle, for example of a fiber-reinforced plastic act.

The carrier layer can be configured in such an optimized (weight) manner that, in the areas in which only a low mechanical stability is required, it has openings in the form of material recesses or else an open-pore cellular structure. When using compressed fiber mats, the carrier layer system-related often has a plurality of small openings between the individual fibers or fiber bundles.

All openings, material recesses or openings referred to above in relation to the decorative layer or the carrier layer should be understood as "openings" in the sense according to the invention. Another characteristic of an opening according to the invention is that these can have any shape, wherein the diameter of the openings is preferably less than 5 mm, more preferably less than 2 mm and most preferably less than 1 mm.

By contrast with the methods or components known from the prior art, it can be avoided by the present invention that foam material is pressed through the openings of the decorative layer and / or the carrier layer or an additional complicated sealing of the openings is required before the foam layer is applied is, for example, by previously laminated films.

Preferably, in addition to a first polyurethane foam, the haptic layer at least partially consists of a second polyurethane foam having a different chemical composition or other physical properties.

In this case, the second polyurethane foam from the first polyurethane foam, for example, by a different blowing agent content, a different first component of a different polyol or a different second component of a different isocyanate differ.

In a preferred embodiment variant, a first polyurethane foam is applied to a decorative layer provided with openings such that only the regions of the decorative layer having the openings are covered by the first polyurethane foam. The second polyurethane foam on the other hand, the entire surface is applied to the decorative layer and surrounds the areas in which the first polyurethane foam is arranged. In this case, the first polyurethane foam primarily serves to seal the openings present in the decorative layer, whereas the second polyurethane foam serves to set the desired feel of the component.

Inasmuch as components with varying haptic properties are to be realized, it is of course conceivable to arrange further polyurethane foams in the production of the haptic layer at least in regions on the decorative layer or the previously applied foams.

Furthermore, it is also conceivable that the decorative layer has several (groups of) openings, where it is necessary to seal them by (further) polyurethane foams having different properties.

Behind the openings of the decorative layer penetrating functional elements can be arranged within the haptic layer and / or the haptic layer and / or the carrier layer. The functional elements may be switches, light sources, loudspeakers, sensors, ventilation devices or the like.

In a further preferred embodiment variant, a first foam system with greatly restricted flow behavior is applied to strongly inclined component geometries, especially those based on the position in the tool. The first foam system preferably has a pasty state of aggregation after the components have been mixed. A second foam system is applied to the less inclined, in particular, again based on the position in the tool, horizontal component areas.

In addition, the first, pasty foam system can be applied only or additionally to the component edges. In this case, the first foam system forms a kind of trough into which the second foam system can be introduced without the need for additional external sealing of the tools.

The inventive method used to produce such components comprises inserting a decorative layer into an open mold or an open mold half, applying a haptic layer of a low-energy foam system of at least one polyurethane foam to the exposed side of the decorative layer and bringing the composite into contact and bonding made of decorative layer and haptic layer with a carrier layer.

In a preferred embodiment, the carrier layer is pressed into the haptic layer for this purpose. The pressing in of the carrier layer preferably takes place within the foaming time of the foam system arranged on the exposed side. In this case, no additional adhesion promoter layer for mounting the carrier layer is required.

After being pressed into the haptic layer, the carrier layer is preferably fixed by a device relative to the decorative layer. This fixation is maintained until the foam system has cured to the extent that no further sinking or pressing of the carrier layer into or through the haptic layer can take place.

After the haptic layer has cured, the component can be removed from the tool.

Alternatively, the application of the carrier layer can take place at a later time. In this case, an activated or activatable adhesion promoter can be arranged on the carrier layer or the exposed side of the foam layer, by means of which the carrier layer is connected to the foam layer.

If the carrier layer has openings into which the foam of the haptic layer, which has not yet fully cured, penetrates through the press-in process, the stroke of the press-fitting is limited in such a way that there is no leakage of foam on the back side of the carrier layer.

In an alternative embodiment, the stroke of the press-fitting is adjusted such that the foam penetrates through the openings of the carrier layer and is laterally distributed on the rear side of the carrier layer, or flows away. By virtue of the mechanical connection formed in this way, it is also possible to combine a combination of materials comprising a carrier layer and a foam layer which does not have sufficient adhesive properties, or a connection of the carrier layer to the foam layer can be achieved after the foam system no longer has adhesive properties.

In a further preferred embodiment variant of the method according to the invention, the haptic layer is formed by applying a first and at least one second polyurethane foam having a different chemical composition or other physical properties.

Preferably, the first and the at least second polyurethane foam are applied to the decorative layer via a multicomponent spray head. The multi-component spray head can be electronically controlled so that the different polyurethanes can be applied in each case partially to the decorative layer. In a preferred embodiment, the application of the plurality of polyurethane foams in one polyline, ie almost simultaneously, for which purpose the Mehrkomponentensprühkopf can be moved relative to the arranged in the open tool or in the open mold half decorative layer in all directions. Alternatively, of course, the tool or the tool half can be moved relative to the spray head.

If the decorative layer has openings at least in some areas, it is preferable for a first polyurethane foam to be applied to the decorative layer in the region of the openings during the formation of the haptic layer and at least a second polyurethane foam applied to the composite of decorative layer and first polyurethane foam for complete formation of the haptic layer.

Brief description of the drawings

1 shows a schematic sectional view of a component according to the known prior art, in which a haptic layer ( 2 ), between a decorative layer ( 1 ) and a carrier layer ( 3 ) is arranged;

2 shows in a schematic sectional view by way of example the production of a component according to the invention;

3 shows an example of a component according to the invention in a schematic sectional view;

4 shows a schematic representation of parts of a system for the exemplary production of components according to the invention, or for carrying out an exemplary method according to the invention;

5 shows by way of example in a schematic sectional view of an inventive component having openings in the decorative layer;

6 shows in a schematic sectional view of a known from the prior art sealing a seam over which a foam is to be applied;

7 schematically represents, as a function of volume as a function of time, the foaming of a low-energy polyurethane foam according to the invention;

8th exemplifies the course of the pressure exerted by the low-energy foam system on the pressed into the foam system carrier layer pressure for different times of injection as a function of time;

9 exemplifies the course of the cavity pressure of a known from the prior art conventional foam system for different water contents as a function of time.

1 shows a schematic sectional view of a component according to the known prior art, in which a haptic layer ( 2 ), between a decorative layer ( 1 ) and a carrier layer ( 3 ) is arranged. In the decorative layer ( 1 ) this may be a sewing dress made of genuine leather. On the reverse side, this sewing dress has an adhesive layer with a haptic layer ( 2 ), for example, a spacer knitted fabric connected. This layer serves to define a defined haptic, ie, a softness or resilience of the decorative surface that is noticeable when the vehicle occupants push against the interior trim part. The on the decorative layer ( 1 ) opposite side of the haptic layer ( 2 ) arranged carrier layer ( 3 ) can be embodied, for example, as an injection-molded part and in turn is provided with an adhesive layer with the haptic layer (US Pat. 2 ) connected.

2 shows a schematic sectional view of the application of a haptic layer according to the invention on a decorative layer ( 1 ). Not shown is the tool in which the decorative layer ( 1 ) is arranged. Several low-energy foam materials ( 21 . 22 . 23 ) are from a multi-component spray head ( 4 ) on the exposed back of the decorative layer ( 1 ) applied. The feeding of the different components ( 421 . 422 . 423 ) of the foam materials to Mehrkomponentensprühkopf happens in each case via a suitable device.

3 shows an inventive component in which behind a decorative layer ( 1 ) several foam materials ( 21 . 22 . 23 ) are arranged at least in regions. Depending on the desired haptics of the component, more or less foam material may be applied in certain areas. On the back is at the of the foam materials ( 21 . 22 . 23 ) Haptikschicht a carrier layer ( 3 ) arranged. The carrier layer has openings over its entire length, without the foam materials penetrating the openings in the carrier layer in such a way that they emerge on the back side of the carrier layer.

4 shows a schematic representation of essential parts of a plant for the exemplary preparation of inventive components, or for carrying out the method according to the invention. The multi-component spray head 4 is with connected to a series of tanks in which the various components ( 422 . 423 , ..., 42n ; 4a . 4b . 4c ) of the foam materials used. Mixing and / or feeding or applying the various foam materials to the decorative layer ( 1 ) can be flexibly controlled via an electronic control unit (CPU). On the decorative layer ( 1 ) are the area. different foam materials ( 22 . 23 ) applied. In this case, the application of the materials can take place simultaneously or else successively as in the present figure.

5 shows a schematic sectional view of a section of a component according to the invention. Wherein, in this embodiment, the decorative layer ( 1 ) has a seam in the middle. In order to close the openings present in the area of the seam due to the system, a first suitable foam material ( 21 ) with a component ( 421 ) used to seal the area of the seam, or the openings. A second foam material ( 22 ) with a different component ( 422 ) is placed above the first component and serves to complete the haptic layer. In the concrete example, the multicomponent spray head ( 4 ) such that it simultaneously supports the foam material ( 21 ) in the region of the seam, as well as the surrounding foam material ( 22 ) can apply.

6 shows a schematic sectional view of a known from the prior art sealing a seam in a decorative layer ( 1 ) with the help of foils ( 12 ) or adhesive tapes ( 13 ). The openings in the seam ( 14 ) are protected by this elaborate process from the ingress of foam material.

7 schematically represents as a function of the volume as a function of time, the foaming of a low-energy polyurethane foam according to the invention. The various regimes "reaction time", "foaming time" and "stick-free time" are shown in chronological succession. In the "reaction time" regime, the complete reaction of the components occurs, whereby the volume of the pasty mixture occupied by the material is still relatively small. At the beginning of the regime "reaction time" (I), the material is applied to the decorative layer of a component according to the invention. The subsequent "frothing time" regime involves an exponential increase in volume up to a maximum at which the volume of the froth almost does not change. In this regime can be beneficial in about reaching the maximum of the volume within. a period of time (III), the carrier layer are pressed into the haptic layer. If the carrier layer is pressed into the haptic layer shortly before reaching the maximum of the volume, the carrier layer advantageously limits the further expansion of the foam material in this case. Because the foam material is a low-energy foam, the forces to be absorbed by the tool in this case are significantly lower than in the known foaming methods of the prior art and the tools can be made much simpler and thus less expensive.

Since the foam material in the "foaming time" regime still has sufficient adhesive properties, the carrier layer bonds to the haptic layer without the need for additional adhesion promoter layers.

8th exemplifies the course of the pressure exerted by the low-energy foam system on the injected into the foam system support layer pressure for different times (III ₁ , ..., III ₇ ) of the pressing as a function of time. In this case, the pressing is preferably done in the foaming of the foam system before the final cellular structure of the foam has formed and the foam has lost its adhesive properties. As can be seen from the figure, the pressure increases in principle with a later time of pressing the carrier layer in the foam system, although the distance between the decorative layer and the carrier layer and thus the thickness of the haptic layer generated with the foam system was kept constant. This is related to the more advanced formation of the cell structure at each later time points. A low pressure can be achieved regardless of the time of pressing in, when the temperature of the introduced foam system is varied. Overall, however, the pressure exerted by the foam system on the carrier layer pressure is very low and reached in the present example maximum pressures of 0.05 to 0.25 bar. These pressures, which are at least a factor of 10 lower than those of the prior art, and the simultaneously greatly restricted flow behavior of the low-energy foam systems used make it possible to use simple tools which, for example, do not have to have an external seal in order to prevent the foam system from escaping from the tool.

The pressure stabilizes in the course of time after reaching a maximum and then falls even slightly caused by the decaying foam reactions.

9 Comparison shows the pressure curve of a known from the prior art foam system. In conventional foam systems, the pressure increases after closing the mold halves (III) and the sealing of the cavity enclosed by the tools (III ') very strong and reaches pressures that are well above 1 bar. In the present example, pressures of up to 2.71 bar are achieved. The water content of the foam system was varied in the experiments shown in this figure, wherein a higher water content principally causes a higher foaming and thus a higher cavity pressure. Only after the removal of the seal (V ') and the opening of the mold halves (V), the pressure drops spontaneously.

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 19854246 A1 [0003]
• DE 102009004612 A1 [0004]

Claims (15)

Interior fitting for a vehicle, in particular a motor vehicle, comprising a carrier layer ( 3 ), and a decorative layer ( 1 ), and a haptic layer arranged between the carrier layer and the decorative layer (US Pat. 2 ), wherein the haptic layer is designed as a foam layer and is formed from a foam system of at least one polyurethane foam, characterized in that it is the foam system is a low-energy foam system. Interior fitting according to claim 1, characterized in that the foam system at least two different polyurethane foams ( 21 . 22 . 23 ). Interior fitting according to claim 2, characterized in that the foam system comprises at least two foams of a polyurethane foam ( 21 . 22 . 23 ), which have different blowing agent contents. Interior fitting according to claim 2 or 3, characterized in that the at least two polyurethane foams ( 21 . 22 . 23 ) comprise at least two different polyol components. Interior fitting according to claim 2 or 3, characterized in that the at least two polyurethane foams ( 21 . 22 . 23 ) have a varying isocyanate component. Interior fitting part according to claim 1, characterized in that the decorative layer ( 1 ) and / or the carrier layer ( 3 ) at least partially have openings. Interior fitting according to claim 1, characterized in that the thickness of the haptic layer ( 2 ) from 0.1 to 15 mm, preferably from 1 to 8 mm, most preferably from 2 to 5 mm. Method for producing interior trim part for a vehicle, in particular a motor vehicle, in which In a first step, a decorative layer is inserted into an open tool or an open mold half in a subsequent step, a haptic layer consisting of a low-energy foam system of at least one polyurethane foam is applied to the exposed side of the decorative layer, In a subsequent step, the composite of decorative layer and haptic layer is brought into contact with and connected to a carrier layer. A method according to claim 8, characterized in that the foam system comprises at least two different polyurethane foams. A method according to claim 9, characterized in that the at least two different polyurethane foams are applied with a multi-component spray head. A method according to claim 10, characterized in that the at least two different polyurethane foams are applied in a polyline of the multi-component spray head. Method according to one of claims 8 to 11, characterized in that the decorative layer at least partially has openings. A method according to claim 12, characterized in that for forming the haptic a first polyurethane foam is applied to the decorative layer in the region of the openings and at least a second polyurethane foam is applied to the composite of decorative layer and first polyurethane foam. Method according to one of the preceding claims, characterized in that the carrier layer is pressed into the haptic layer within the foaming time of the foam system. Method according to one of the preceding claims, characterized in that the foam system is applied in a pasty state of aggregation on the decorative layer.

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