Method for manufacturing vehicle lining member, and lining member manufactured by said method

Abstract

A method for producing a lining element (8), in particular for the interior space of a vehicle, is described, in which a carrier substrate (5) is positioned against a flexible decorative layer with an intervening foam coating and adhesively bonded thereto, and the foam raw material used to form the foam layer (9) is foamed with a gas as a physical foaming agent and coated as expanded foam raw material on the back side of the decorative layer (3) and / or on the side of the carrier substrate (5) facing the decorative layer (3). As long as the expanded foam coating (4) is still fluid, the carrier substrate (5) is positioned at a specified distance relative to the back side of the decorative layer (3) with the expanded foam coating (4) interposed therebetween, so that the decorative layer (3) is bonded to the carrier substrate (5) by the foam coating (4) and held until the crosslinking process of the foam coating (4) is at least substantially complete, and during the step of positioning the carrier substrate (5), the part of the foam layer (4) that fills the original distance of the decorative layer (3) from the carrier substrate (5) is at least regionally expelled by the carrier substrate (5) and plastically compressed.

Description

[Technical field]

[0001] The invention relates to a method for producing a lining element, in particular for the interior space of a vehicle, in which a carrier substrate is positioned against a flexible decorative layer with an intervening foam coating and is adhesively bonded by said foam coating.Furthermore, an internal lining element produced by said method is described, in which the raw material used to form the foam layer is foamed by means of a gas as a physical blowing agent and is coated on the back side of the decorative layer and / or on the side of the carrier substrate facing the decorative layer as a reactive expanded foam raw material.

[0002] Such lining elements are present as interior lining elements, for example in vehicles, in the form of instrument panel covers, door linings, glove boxes, etc. Such lining elements are also used, for example, in boats outdoors. Such lining elements comprise a rigid carrier substrate, which is attached to the chassis side of the vehicle. The carrier substrate serves to carry accessories or attachments, for example electric / electronic units. Such carrier substrates are usually plastic injection-molded elements made from PP or ABS. The visible side of such interior lining elements is formed by a decorative layer. The decorative layer is flexible and may have elastic properties, especially if it is a plastic layer (made, for example, from polyurethane). Between the decorative layer and the carrier layer there is an elastic soft foam layer, in order to give the lining element a so-called "soft touch". Typically, the thickness of such a foam layer is only a few millimeters, usually between 3 and 8 mm. The feel provided by the foam layer, and therefore its hardness, is controlled primarily by the selection of the foam ingredients, the degree of expansion of the foam itself, and the density of the foam layer.

[0003] In the conventional back foaming process for producing such lining elements, the decorative layer is inserted into an open mold consisting of several parts or a plastic material is injected into one of the mold parts. A reactive foaming raw material is then applied to the back side of the decorative layer. The mold is then closed, the other part of the mold carrying the carrier substrate. In the closed mold, a predefined gap remains between the carrier substrate and the decorative layer. The reactive foaming raw material contains a chemical foaming agent. This is water. As a result of the reaction between the foaming components (in the case of polyurethane, this is the polyol component and the isocyanate component), the raw material polymerizes and at the same time foams due to the reaction of the isocyanate with water, which releases gas. By the end of the crosslinking process, a foam layer is formed between the decorative layer and the carrier substrate. At the same time, a crosslinking process is used, by which the foam is adhesively bonded to the decorative layer and to the carrier substrate. An adhesive primer can assist the adhesive bonding of the foam layer to the decorative layer and to the carrier substrate. To form such a foam layer, for example for automotive interior linings, a foam having a density of 150-200 kg / m3 is usually required. 3 A polyurethane flexible foam of the above formula is used.

[0004] In this method, it should be taken into account that during the chemical foaming and the associated polymerization, very high pressures and temperatures occur in the mold. This not only places high demands on the molds or mold components used for this purpose. It should also be noted that the decorative layer must be of such quality that it can withstand the effects, especially temperature effects, of possibly different temperature distributions in the mold. The different temperature distributions must not result in the visible side of the decorative layer having a different appearance depending on the temperature. If an open material is used as the decorative layer in this method, pressures of up to 2-5 bar can occur in such molds, which can cause the foam to be pressed against the visible side of the decorative layer and lead to its rupture. The use of such materials for providing the decorative layer therefore requires costly sealing measures before the reactive, not yet expanded raw material is applied.

[0005] German patent application DE 10 2011 005 343 A1 discloses a method for producing such lining elements in an open mold. In this method, a low-energy foaming system, i.e. one that does not generate too much pressure, is used. The cohesive state of the reactive foaming raw material applied to the back side of the decorative layer is selected here such that it is not flowable after its application. This is because the foaming raw material does not penetrate into any openings present in the decorative layer. If it is desired to bond the carrier substrate without further adhesive primers or other adhesives, this can be pressed onto the surface of the foam raw material when the foaming process is completed or at least nearly completed. However, the so-called "tack-free period" of the foam material must not have been reached at the time of incorporation of the carrier substrate. To allow the desired adhesive bond, the foam must ultimately still have a sufficiently adhesive surface.

[0006] German utility model application DE 20 2008 017 784 U1 discloses an inner lining element with an absorbent material. According to the method for producing such an inner lining element described in the prior art, a partially physically expanded foam material is applied. As is known per se, the material contains a chemical foaming agent. In order to apply the foam to the absorbent decorative material without the foam penetrating the material, it is intended to wait a while after the foam material is applied until the viscosity is sufficiently high due to the crosslinking process already in progress, so that the foam amount cannot penetrate the decorative layer when the carrier substrate is attached. In this respect, the method described in the prior art does not differ from the method described earlier in DE 10 2011 005 343 A1.

[0007] Although these known methods allow for back foaming of the decorative layer with openings, the time window in which the carrier substrate is pressed against the foam surface that is not yet completely crosslinked must be very precisely adapted and observed. Finally, the coated foaming material should be almost completely foamed before it is brought into contact with the carrier substrate. On the other hand, the tack-free time (i.e. the point in time at which the foam is no longer adhesive) must not yet be reached. This time window is usually only a few seconds. When the carrier substrate is pressed against the almost completely polymerized foam, the foam is compressed. This leads to different hardness over the planar extension of the inner lining element, and therefore different tactile sensations over the planar extension, if the distance between the back side of the decorative layer and the carrier substrate, and thus the thickness of the foam layer over the entire planar extension of the inner lining element, is not uniform. In this case, the hardness of the foam layer is increased in the areas of the inner lining element where the distance between the decorative layer and the carrier layer is smaller. This is especially true for carrier substrates which, due to other requirements, cannot provide a uniform distance to the decorative layer, which can only be compensated for very poorly, if at all, by coating the foam raw material with different thicknesses.

[0008] Based on the prior art discussed herein, the present invention is therefore based on the problem of providing a method for the manufacture of an internal lining element comprising a soft elastic foam layer between a decorative layer and a carrier substrate, which avoids the previously indicated drawbacks and allows less restricted design freedom for providing such an internal lining element. Furthermore, it would be desirable if the manufacturing method could be simplified, in particular in terms of time.

[0009] This problem is solved by the universal method mentioned at the beginning, in which a carrier substrate is positioned at a specified distance from the back side of the decorative layer with the expanded foam coating interposed therebetween, as long as the expanded foam coating is still fluid, thereby bonding the decorative layer to the carrier substrate by means of the foam coating and holding it until the crosslinking process of the foam coating is at least approximately complete, during the positioning step of the carrier substrate, the part of the foam layer that fills the original distance of the decorative layer from the carrier substrate is at least regionally expelled by the carrier substrate and plastically compressed.

[0010] In this method, the foam material is coated in an already foamed and expanded state and coated on the back side of the decorative layer, or on the side of the carrier substrate facing the decorative layer, or on the decorative layer and the carrier substrate. Since the foaming raw material is applied in an already foamed state, such two foam layers can be coated on the back side of the decorative layer and on the side of the carrier substrate facing the decorative layer, and still result in a homogeneous foam layer. As the foaming agent, a physical foaming agent is used, for example a gas such as carbon dioxide or nitrogen. It is understood that other suitable gases can also be used as foaming agents. In contrast to the conventional method of foaming a raw material with a chemical foaming agent, this does not occur by a chemical reaction inside the coated raw material. A combination of already expanded foam coatings with other foam coatings and / or foam layers is also possible, for example if a first foam coating is applied on the back side of the decorative layer, for example as described above, as a foam coating with open pores, and a second foam coating is applied on the side of the carrier substrate facing the decorative layer as a foam coating with closed pores, or is otherwise connected to the carrier substrate. Such a combination can also be made if the decorative layer is covered on the back side with a foam layer in a first step, before being coated with the expanded foam coating according to the invention. In order to keep the carbon dioxide emissions low when producing such lining elements, it is preferred not to use carbon dioxide as gaseous blowing agent, but for example nitrogen.

[0011] Since the foam coating is applied already in an expanded state, the carrier substrate can be positioned against the decorative layer immediately after the application of the expanded foam coating. The foam coating on the back side of the decorative layer means that the carrier substrate is in contact with the expanded foam coating that is applied thereon. Regardless of whether the foam coating is applied to the decorative layer and / or to the carrier substrate, unlike the conventional method, it is not necessary to wait for the time required for chemical foaming in order to be able to position the carrier substrate. In the known method for positioning the carrier substrate, it is further necessary to wait for the time for the cells formed by the foaming process to burst and form a foam coating with open pores. Thus, in the conventional method, whether the carrier substrate is positioned too early also depends on the time at which the open pore foam is formed.

[0012] In the claimed method, at the time of positioning the carrier substrate against the decorative layer with the foam coating in between, the polymerization has only just started, so that it is still at least somewhat fluid and can be discharged without problems. This can be done by positioning and adjusting the substrate against the decorative layer. The crosslinking process is then waited for at least approximately to be completed before the lining element is removed from the mould. Discharging the expanded foam coating offers a number of advantages. This can, for example, provide uniformity of the expanded foam coating, which is typically applied by spraying, inside the gap of the mould between the decorative layer and the carrier substrate, and also allows the expanded foam coating, which is not required to fill this gap, to be discharged from the gap of the mould. In this context, what is interesting in relation to the lining element produced is that this provides a lining element with a uniform hardness, even with different gap widths, independent of the thickness of the foam coating material between the decorative layer and the carrier substrate. This ensures that undesired compression of the foam does not occur, at least to a significant extent. Foam compression of 5-30%, preferably 10-20%, especially 10-15%, is not undesirable since this is taken into account in forming the foam layer.

[0013] The important point of the method is that the time for which the carrier substrate must be positioned against the decorative layer, i.e., the time for which the carrier substrate is brought into contact with the foam coating, for example, in the case of foam coating covering on the back side of the decorative layer, is significantly increased. This not only shortens the manufacturing process by eliminating waiting times, as occurs with chemical foaming agents, but also provides a method that is less susceptible in terms of long-term reproducibility. The use of catalysts in the reactive foam raw material can further shorten the reaction time, i.e. the time required for the polymerization process to be completed, which also makes it possible to further shorten the manufacture of such lining elements. When chemical foaming agents are used, the crosslinking process only starts after the expansion process is completed. In the method according to the invention, for example, when the back side of the decorative layer is provided with an expanded foam coating, the carrier substrate is usually brought into contact during a time window that has not yet reached 70% of the reaction time. The same applies in the case of covering the carrier substrate or in the case of foam coating on the decorative layer and the carrier substrate. In a particularly preferred embodiment, the carrier substrate is positioned when 50% of the reaction time has not yet elapsed. In relation to the reaction time, the earlier the carrier substrate is positioned against the decorative layer with the foam coating in between, the better the adhesive bond will be, since the foam coating will be in contact with both the decorative layer and the carrier substrate. Thus, by positioning the carrier substrate against the decorative layer with the expanded foam coating in between earlier than in the prior art, the polymerization process has not yet progressed so much that the foam structure is not damaged by the movement of the foam. This is taken advantage of in the subject matter of the present invention.

[0014] The relatively long time window for positioning the carrier substrate allows the production of larger lining members that require some time for coating with expanded foam (usually by spraying) without having to accept the disadvantages associated with positioning the carrier substrate against the decorative layer in terms of foam quality or adhesive bonding of the foam coating.

[0015] The possibility of discharging a part of the expanded foam coating through the carrier substrate allows the method to be carried out to produce a thicker foam coating than is actually required, which allows a foam coating with a larger volume than is required. This is presented in a preferred embodiment. The distance between the decorative layer and the carrier substrate can be brought about by spacer elements, for example by spacer pins, for example as part of the carrier substrate or integrated into the mould. The use of positioning calibers is also entirely possible. Discharging a constant amount of the expanded foam coating, and thus modelling or distributing the foam coating by the carrier substrate with a relative movement between the carrier substrate and the decorative layer, leads to a homogenous foam in terms of compression in the space between the decorative layer and the carrier substrate, while the foam quality is constant.

[0016] In this method, due to the flowability of the expanded foam coating at the time of positioning the carrier substrate against the decorative layer, the foam can be introduced into the undercuts of the carrier substrate, with the advantage that the bonding of the polymerized foam layer to the carrier substrate is not only by adhesion but also by form-fitting. This is particularly true when the foam coating is not applied to the carrier substrate but is applied to the back side of the decorative layer. By simply pressing the carrier substrate against the expanded foam coating, the carrier substrate is pushed into the undercut structures present on the side of the carrier substrate facing the foam coating. To assist such penetration of the foam coating into the undercut structures of the carrier substrate on the side facing the decorative layer, the carrier substrate can also be moved in the plane of the decorative layer, floating above the foam coating. The terms used in the description regarding the flowability of the foam coating after the start of polymerization do not necessarily mean that the foam flows only by gravity, but in particular can be modeled and thus moved without significantly changing its viscosity. A certain degree of compression is possible.

[0017] Excess foam coating can be pushed out of the space between the decorative layer and the carrier substrate laterally and can be cut off, for example, after the crosslinking process of the foam coating is completed. In such a method design, in order to avoid excessive extrusion of the expanded foam coating, the expanded foam coating can be applied in a relatively thin thickness in the peripheral area around the decorative layer or around the foam ingress openings provided therein, or with a decreasing thickness towards the periphery or ingress openings. According to another embodiment, it is provided that the mould and / or the carrier substrate are provided with openings or channels in the peripheral area, through which the foam ejected by positioning the carrier substrate can escape from the gap between the decorative layer and the carrier substrate. It is also possible that the foam coating is compressed by the pressing of the carrier substrate, if the foam coating is not ejected or not completely ejected from the space between the decorative layer and the carrier substrate as a result of the pressing action of the carrier substrate. This is possible with the described method. This is because an open-celled expanded foam is applied to form the foam coating, and the gas contained in the cells of the foam is forced from one cell to the next and can thus be extruded from the foam coating. This measure plastically compresses the foam coating. If it is undesirable for the foam to escape from the space between the decorative layer and the carrier substrate, the periphery of the intermediate space can be sealed.

[0018] A further particular advantage of the present method is that the foam coating can be spray coated based on the desired flowability, which is contemplated in preferred embodiments where spray application is performed in smaller droplets, allowing for particularly good control of the coating thickness of the expanded foam coating.

[0019] No additional temperature is introduced into the composite being produced as a result of the application of the already foamed foam coating. Typically, in conventional methods using chemical blowing agents, water is used as the chemical blowing agent. The reaction involved is exothermic. In the claimed method, no exothermic reaction is required for foaming, so shrinkage phenomena do not have to be considered or accommodated. Furthermore, open pore formers as additives are not required in the claimed method.

[0020] The production of the lining element is carried out without pressure: the applied pressure is usually less than 1 bar, even preferably less than 0.5 bar.

[0021] In addition, the polymerization can be carried out at low temperatures, which in any case do not adversely affect the decorative layer.

[0022] The layer thickness of the foam layer produced in this way can be 15 mm to 20 mm, in particular 10 mm, especially 5 mm. Thickness differences in the space between the decorative layer and the carrier substrate can occur due to plastic modeling of the foam coating.

[0023] The density of the foam coating is freely selectable, e.g. between 70 and 700 kg / m 3 , especially 200-500kg / m 3 Typically, positioning the carrier substrate against the decorative layer involves some compression of the foam coating, which can increase the density of the foam coating by, for example, 5% to 30%.

[0024] The preferred density of the foam coating is about 250 kg / m 3 which can be achieved by positioning the carrier substrate (with compression of the foam coating) to a density of e.g. 300 kg / m 3 increases.

[0025] In this method, the space between the decorative layer and the carrier substrate forms a mold in which the foam coating is polymerized, thereby obtaining the desired shape.

[0026] The foam layer formed from the foam coating after polymerization is complete can be formed as a flexible foam layer or a semi-rigid foam layer depending on the desired requirements.

[0027] Usually, the carrier substrate is positioned on the expanded foam coating immediately after the coating. Since the polymerization has already started during the mixing of the reactive components (polyol and isocyanate in the case of polyurethane), the polymerization and therefore the reaction time has already begun at this point. However, as already indicated above, this does not have a detrimental effect on the ejection of the foam by the carrier substrate.

[0028] Although the above-mentioned processes can essentially be carried out in a closed mold without pressure and without exothermic heating, for reasons of convenience they are usually carried out in an open mold.

[0029] In a preferred embodiment, anhydrous foam ingredients are spray applied along with a gaseous blowing agent.

[0030] In the foregoing embodiments, even when application of an anhydrous expanded foam coating is contemplated, it is possible that a certain percentage of a chemical blowing agent may be included to achieve certain effects on the foam coating.

[0031] The foam coating of the produced lining element is usually a polyurethane foam. The incorporation of gas can take place before or during the mixing of the polyol and isocyanate components. It is also possible to add the gas to one of the components before mixing the two components. In spray application, a gas, usually nitrogen, is fed to the reaction mixture in the mixing chamber. An actual volume increase occurs at the outlet of the application nozzle, whereby the expanded foam is coated on the back side of the decorative layer. WO 2007 / 127623 A1 describes a spray method. The embodiments relating to spray application in the prior art are hereby expressly incorporated into the subject matter of the description, even if they are carried out in a different context. It is also understood that other polymerizable foams can be used to form the foam layer of the lining element.

[0032] The decorative layer can ultimately be any flexible sheet-like layer, such as thermoplastic sheets, polyurethanes, PVC, TPO, woven fabrics, leather, artificial leather, etc. Pressure- and temperature-sensitive materials can be used without problems, since neither pressure nor high temperatures are generated in the process. Such decorative layers can also have openings. Fracture of the foam attached to the visible side of the decorative layer is not a concern, since no pressure is applied during foam coating.

[0033] The carrier substrate can be, as in conventional methods, a plastic component, for example PP or ABS. They can have openings, but this does not matter, since no pressure is applied during application and polymerization. In fact, the foam coating can be forced into the openings of the carrier substrate. However, they do not provide a path for the foam to escape by pressure, as in known methods using closed moulds. Coating with semi-rigid expanded foam therefore allows the use of a carrier substrate that is entirely porous or permeable, and thus has a certain degree of permeability. The carrier substrate can thus be, for example, a fibre mat, for example a glass fibre mat, or a mat made of natural fibres. In the course of positioning the carrier substrate against the decorative layer, the foam coating can be incorporated into such a carrier substrate, so that the foam coating is incorporated into the foam. Then, after the polymerization process is complete, the carrier substrate is also connected with the foam layer by form-fitting.

[0034] In the method described above, it is entirely possible that the foam layer is composed of two or more individual foam layers (e.g., with different densities from each other), which are all coated as an expanded foam coating. This is not inconsistent with the previous embodiment, in which these foam layers are formed from individual foam part layers, which are themselves also coated on the foam layer as part of a decorative layer or as part of a carrier substrate.

[0035] The present invention will now be described based on embodiments with reference to the accompanying drawings. [Brief description of the drawings]

[0036] [Figure 1] FIG. 2 shows a schematic diagram of an open mold (with a decorative layer inside) for producing an interior lining component for an automobile. [Diagram 2] Shown is the mold of FIG. 1 with an internal decorative layer back foamed with an expanded and coated foam coating. [Diagram 3]a shows the carrier substrate to be positioned above the foam coating, and b shows the carrier substrate positioned above the foam coating. [Figure 4] 3 shows the inner lining member removed from the mold. [Diagram 5] 5 shows the time sequence of each process step in the manufacture of the inner lining component of FIG. 4. [Figure 6] 5 shows the time course of an internal lining element produced similarly in an open form according to the prior art (corresponding to FIG. 5). [Figure 7] A partial cross-sectional view showing the arrangement of an open mold and a carrier substrate to be positioned, where a shows an opening for forming a leak hole inside the lining member, b shows the carrier substrate positioned against the decorative layer with a foam coating interposed therebetween, and c shows the lining member removed from the mold (with the leak hole formed therein). [Figure 8] 7a-7c depict a partial view corresponding to the depiction of FIG. 7a, showing another embodiment of a leak outlet in the inner lining member;

[0037] The open mould 1 comprises a cavity 2, in which a decorative layer 3 is arranged. In the illustrated embodiment, the decorative layer 3 is already formed in the mould, in this embodiment sprayed with a corresponding polyurethane material. The side of the mould 1 facing the cavity 2 is structured with a leather-like grain, so that the decorative layer 5 has a leather-like grain on the underside in FIG. 1. In the illustrated embodiment, the back side of the decorative layer 3 is coated in a subsequent process step, i.e. by spraying, with a reactive expanded foam raw material, in order to form an interior lining component for a vehicle. The size of the droplets coming out of the spray nozzle is relatively small, for example 0.1-1 mm. In the illustrated embodiment, the foam coating 4 is an expanded polyurethane soft foam. The foam coating is identified in FIG. 2 with the reference number 4. The foam coating in the illustrated embodiment is an open-cell soft foam foamed with nitrogen, which is applied in the foamed state onto the decorative layer 3. Immediately after application of the foam coating 4, i.e. just at the beginning of the reaction time associated with the polymerization process, the carrier substrate 5 is brought into contact with the upper side of the foam coating 4 and pressed slightly into said foam coating (see Figs. 3a, 3b). In the illustrated embodiment, the carrier substrate 5 is a rigid ABS plastic part. Pressing the carrier substrate 5 into the foam coating 4 serves to apply the foam to the gaps (hollows) between the decorative layer 3 and the carrier substrate 5 and to incorporate said foam into the undercut structures of the carrier substrate 5 facing the decorative layer 3. Such undercut structures are identified by the reference number 6 in the carrier substrate 5, for example in the form of double-tailed undercut structures. The formation of these undercut structures serves the purpose of connecting the carrier substrate 5 to the polymerized foam layer not only adhesively but also form-fittingly. In the illustrated embodiment, the carrier substrate 5 is structured and comprises projections 7, which are pressed deeper into the foam coating 4 than the parts adjacent to the projections 7. In this case, the fluidity and / or mobility of the foam coating 4 at the time when the foam coating 4 and the carrier substrate 5 are integrated is utilized.

[0038] The carrier substrate 5 is pressed into the foam coating 4 until a predefined distance to the decorative layer 3 is established. In the illustrated embodiment, the carrier substrate 5 is provided with a stop extension, which is placed on the upper side of the mould 1 when the predefined distance to the decorative layer 3 is reached. The foam coating 4 is applied with a larger volume than would otherwise be required in order to fill the gap between the decorative layer 3 and the carrier substrate 5 at the location shown in FIG. 3b. The excess foam is discharged laterally from the mould cavity 2 (see FIG. 3b). This entails a certain compression of the foam coating 4, but is possible without problems since the foam coating 4 is an open-cell foam coating. The finished inner lining element 8 is then removed from the mould 1, which can be cleaned if necessary and subsequently further processed or installed. Here, the polymerized foam layer is identified with the reference number 9.

[0039] The time sequence of the process steps for the chemical behavior of the expanded foam coating can be seen from FIG. 5. In FIG. 5, the x-axis represents time and the y-axis represents the foam volume. In the above method, the expanded foam is coated, so that the foam volume remains constant over time. The foam volume does not necessarily change due to the aforementioned expulsion process when positioning the carrier substrate 5. However, it may be provided that the pressing of the carrier substrate 5 produces a certain compression effect on the foam coating 4, which is typically 8-15%. At time (1), the expanded foam is coated by spraying. The reaction time of the reactive foam starts to run with the coating of the foam. Since the back side of the decorative layer 3 cannot be sprayed simultaneously over its entire surface, the reaction time (distributed at different times over the back side of the decorative layer 3) starts before the time (2) when the carrier substrate 5 comes into contact with the expandable foam coating and is positioned. The time window during which the carrier substrate 5 is positioned as intended ends at time (3). At time (4) in this figure, the tack-free time is reached. After this, the surface of the foam coating 4 is no longer adhesive. The intended time window therefore ends well before time (4). In the illustrated embodiment, the reactive foam coating 4 is adjusted by the addition of a catalyst in such a way that the tack-free time is reached after about 25 seconds. This leaves about 15-20 seconds of time for positioning the carrier substrate in the method. If the expanded foam coating is adjusted differently, i.e. if the time window to the tack-free time is set somewhat longer, the time window for positioning the carrier substrate will be correspondingly longer. In this way, the time window can be adjusted. The size of this time window can be influenced by the rear surface plane of the decorative layer 3, on which the foam coating 4 is applied. A larger surface requires more time for foam application.

[0040] FIG. 6 shows a sequence of a method for producing an internal lining component, in which reactive, not yet expanded raw materials are coated on the back side of the decorative layer in an open mold. In order to position the carrier substrate, one must first wait for the foaming process to be completed, i.e. until the foaming process is completely or almost completely completed. Time point (2) is therefore much later than in the timeline shown in FIG. 5 for the method according to the invention, as required in relation to the reaction time. The time window for positioning the carrier substrate (the length of time between (2) and (3)) is very short in a far advanced polymerization process, due to its close proximity in time to the tack-free time. If the carrier substrate is positioned too early in contact with the foam surface, a harder foam is formed. If the carrier substrate is positioned too late, the desired quality of the adhesive bond is no longer obtained. Finally, at a time point (4) shortly thereafter, the tack-free time is reached. In this method, the reaction time can of course be shortened by using a catalyst. However, this also shortens the time window for positioning the carrier substrate. Thus, in this method, the reaction time of the foam-forming ingredients is adjusted so that the time window for positioning the support substrate is long enough.

[0041] Fig. 7a shows a cross-section of a mould 1.1 on which a decorative layer 3.1 has been laid and / or formed on the moulding surface of the mould 1.1. The mould 1.1 is designed so that the internal lining parts produced thereby can be produced with a leak (for example for use in an air conditioning outlet cover). For this purpose, the mould 1.1 is provided with protrusions 10 which provide a weak point in the foam layer to be produced. The protrusions 10 extend all around the leak to be produced and taper in the direction of the carrier substrate 5.1. The carrier substrate 5.1 has an opening 11 in the area of ​​the leak to be produced.

[0042] After the expanded foam is sprayed on the back side of the decorative layer 3.1 to provide a foam coating, the carrier substrate 5.1 is positioned against the decorative layer 3.1. In the region of the protrusions 10, the distance between the carrier substrate 5.1 and the decorative layer 3.1 is minimized. This means that the thickness of the foam coating 4.1 is very small in the gap distance between the protrusions 10 and the carrier substrate 5.1. In order to bond the carrier substrate 5.1 to the decorative layer 3.1, a foam coating is present between the decorative layer 3.1 and the carrier substrate 5.1. By positioning the carrier substrate 5.1 on the foam coating 4.1 (see FIG. 7b), the foam coating is also pressed into the opening 11. After the polymerization process is completed, the protrusions 10 provide a predetermined break point at which the polymerized foam coating (foam layer 9.1) together with the decorative layer 3.1 to which it is bonded is separated, for example by tearing, in the middle of the leak to be created (shown by dashed line). This is usually done after the inner lining element has been removed from the mould 1.1. The leak openings 12 (see FIG. 7c) of the inner lining element 8.1 thus created can then be provided with further elements passing through the inner lining element 8.1.

[0043] FIG. 8a shows an embodiment of a component corresponding to the example of FIGS. 7a-c, in which the carrier substrate 5.2 is provided with a protrusion 13 with its tip facing the mould 1.2. In the example shown in FIGS. 8a, 8b, the mould 1.2 is likewise provided with a protrusion 10.1, but with a flat portion 14, unlike the protrusion 10 of the mould 1.1, which is tapered towards the carrier substrate 5.1. The inner lining element 8.2 is produced in the mould 1.2 in the same way as previously described in the example of FIGS. 7a-7c. After the foam coating 4.2 has polymerised, this gives rise to a foam layer 9.2, which is separated by the polymerised foam together with the decorative layer 3.2 adhering thereto emerging from the area of ​​the leak 12.1 to be produced, thus releasing the leak 12.1.

[0044] The present invention has been described on the basis of examples, and those skilled in the art have many more possibilities for implementing the invention, the embodiments of which do not need to be described in detail, without departing from the scope of the present claims. [Explanation of symbols]

[0045] Type 1,1.1,1.2 2 Cavity 3,3.1,3.2 Decorative layer 4,4.1,4.2 Foam Coating 5, 5.1, 5.2 Support Substrate 6 Undercut structure 7 protrusions 8, 8.1, 8.2 Inner lining members 9, 9.1, 9.2 Foam layer 10,10.1 Protrusion 11,11.1 Open area 12,12.1 Leakage port 13 protrusions 14 Flat area

Claims

1. A method for producing a lining element (8, 8.1, 8.2), in particular for the interior space of a vehicle, comprising: a carrier substrate (5, 5.1, 5.2) positioned against a flexible decorative layer (3, 3.1, 3.2) with an intervening foam coating (4, 4.1, 4.2) and adhesively bonded by said foam coating, the raw material used to form the foam layer (9, 9.1, 9.2) being foamed by means of a gas as a physical foaming agent and being coated on the back side of the decorative layer (3, 3.1, 3.2) and / or on the side of the carrier substrate (5, 5.1, 5.2) facing the decorative layer (3, 3.1, 3.2) as a reactive expanded foam raw material, As long as the expanded foam coating (4, 4.1, 4.2) is still fluid, the carrier substrate (5, 5.1, 5.2) is positioned at a defined distance with respect to the back side of the decorative layer (3, 3.1, 3.2) with the expanded foam coating (4, 4.1, 4.2) interposed therebetween, and the step of positioning the carrier substrate (5, 5.1, 5.2) thereby removes the decorative layer (3, 3.1, 3.2) from the carrier substrate (5, 5.1, 5.2). .2), is at least regionally evacuated and plastically compressed by the carrier substrate, whereby the decorative layer (3, 3.1, 3.2) is bonded to the carrier substrate (5, 5.1, 5.2) by the foam coating (4, 4.1, 4.2) and is held together until the crosslinking process of the foam coating (4, 4.1, 4.2) is at least substantially completed.

2. 2. The method according to claim 1, characterized in that the carrier substrate (5, 5.1, 5.2) is positioned against the decorative layer (3, 3.1, 3.2) when the reaction time length has not yet exceeded 70%, in particular 50% of the reaction time.

3. 2. The method according to claim 1, characterized in that the expanded foam coating (4, 4.1, 4.2) is applied with a volume larger than the volume required to fill the gap between the decorative layer (3, 3.1, 3.2) and the carrier substrate (5, 5.1, 5.2).

4. 2. The method according to claim 1, characterized in that the carrier substrate (5, 5.1, 5.2) is moved relative to the expanded foam coating (4, 4.1, 4.2) coated thereon in relation to the distance between the carrier substrate and the decorative layer (3, 3.1, 3.2) and in relation to the position of the carrier substrate relative to the flat extension of the decorative layer (3, 3.1, 3.2) before the carrier substrate (5, 5.1, 5.2) is held until the crosslinking process of the foam coating (4, 4.1, 4.2) is at least substantially completed.

5. 2. The method according to claim 1, characterized in that the carrier substrate (5, 5.1, 5.2) is positioned on the rear side of the decorative layer (3, 3.1, 3.2) in relation to the distance from the carrier substrate (5, 5.1, 5.2) to the rear side of the decorative layer (3, 3.1, 3.2) by a spacer or by a positioning calibre on which the carrier substrate (5, 5.1, 5.2) is positioned.

6. 2. The method according to claim 1, characterized in that the process steps are carried out in an open mould (1, 1.1, 1.2) and that in a first step the decorative layer (3, 3.1, 3.2) is inserted into the mould or produced in the mould, which is then followed by further steps in the open mould (1, 1.1, 1.2).

7. 2. The method according to claim 1, characterized in that a coating of expanded foam raw material is completely or partially coated onto a foam layer arranged on the side of the decorative layer facing the carrier substrate or on the side of the carrier substrate facing the decorative layer.

8. 2. The method according to claim 1, characterized in that the foamed and expanded foam coating (4, 4.1, 4.2) is applied by spraying.

9. 2. The method according to claim 1, characterized in that to form the foam layer (9, 9.1, 9.2) a reactive foamed and expanded polyurethane foam raw material is coated as a foam coating (4, 4.1, 4.2), in particular to form a polyurethane soft foam or a semi-rigid polyurethane foam.

10. 10. The method of claim 9, wherein the blowing agent is introduced into the reactive material prior to and / or during the mixing process, or into the polyol and / or isocyanate components used to prepare the reactive material.

11. 10. The method of claim 9, wherein the foam raw material to be coated, foamed by the blowing agent, is free of water, or at least largely free of water.

12. 2. The method according to claim 1, characterized in that the support substrate (5.1, 5.2) has at least one leak opening and the lining element (8, 8.1, 8.2) is manufactured with a predetermined break point to create the leak opening (12, 12.1).

13. The method of claim 1, characterized in that the carrier substrate is permeable to the expanded foam coating, and the foam material is incorporated into the carrier substrate by positioning the carrier substrate against the decorative layer through the expanded foam coating.

14. 14. The method according to claim 13, characterized in that a fiber mat is used as the support substrate.

15. A lining element, in particular an interior lining element for a motor vehicle, manufactured by the method according to any one of claims 1 to 14, characterized in that the hardness of the foam layer (9, 9.1, 9.2) is homogeneous over the planar extension of the lining element (8, 8.1, 8.2), even in the presence of gaps of various sizes between the decorative layer (3, 3.1, 3.2) and the carrier substrate (5.1, 5.2).

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