US-12623379-B2 - Method for producing a lining part for a vehicle, and lining part produced using said method

US12623379B2US 12623379 B2US12623379 B2US 12623379B2US-12623379-B2

Abstract

In a method for producing a lining part, in particular for the interior of a vehicle, a support substrate is positioned opposite a flexible decorative layer with the interposition of a foam coating, and the support substrate is adhesively connected thereto, wherein the raw foam compound used to form the foam layer is foamed using a gas as a physical blowing agent and is applied onto the rear face of the decorative layer and/or the support substrate face facing the decorative layer in the form of an expanded foam. As long as the expanded foam coating is still flowable, the support substrate is positioned at a defined distance to the rear face of the decorative layer with the interposition of the expanded foam coating so that the decorative layer is connected to the support substrate by the foam coating and is held until the cross-linking process of the foam coating has at least mostly concluded, wherein a part of the foam layer which fills the original distance between the decorative layer and the support substrate is displaced and plastically compressed at least in some regions by the support substrate during the process of positioning same.

Inventors

Rudi Farinon
Geert Trossaert
Koen Vanlandschoot
Yvan Vanluchene

Assignees

ASCORIUM GMBH

Dates

Publication Date: 20260512
Application Date: 20220518
Priority Date: 20210625

Claims (20)

1 . A method for producing a lining part comprising a support substrate, a flexible decorative layer, and a foam layer, wherein the support substrate is positioned opposite the decorative layer with the foam layer therebetween, the method comprising: applying the foam layer as an expanded foam layer, foamed with a gas as a physical blowing agent, onto a back side of the decorative layer and/or onto a side of the support substrate facing the decorative layer; and as long as the expanded foam layer is still flowable, positioning the support substrate at a defined distance from the back side of the decorative layer with interposition of the expanded foam layer, whereby, during the process of positioning the support substrate, at least a part of the expanded foam layer between the decorative layer and the support substrate is displaced and is plastically compressed, so that the decorative layer is bonded to the support substrate by the expanded foam layer, then holding the support substrate at its defined distance to the back side of the decorative layer until the cross-linking process of the expanded foam layer is at least mostly completed.
2 . The method of claim 1 , wherein the support substrate is positioned relative to the decorative layer in a reaction time interval when 70% of the reaction time of the cross-linking process has not yet been exceeded.
3 . The method of claim 1 , wherein the support substrate is positioned relative to the decorative layer in a reaction time interval when 50% of the reaction time of the cross-linking process has not yet been exceeded.
4 . The method of claim 1 , wherein the expanded foam layer is applied with a volume that is larger than required for filling the gap between the decorative layer and the support substrate.
5 . The method of claim 1 , wherein the support substrate is moved relative to its distance from the decorative layer and relative to a position thereof in relation to the planar extension of the decorative layer with respect to the expanded foam layer applied thereto, before holding the support substrate until the cross-linking process of the expanded foam layer is at least mostly completed.
6 . The method of claim 1 , wherein the support substrate is positioned relative to the back side of the decorative layer with spacers or a positioning caliber, on which the support substrate is positioned at the defined distance of the support substrate to the back side of the decorative layer.
7 . The method of claim 1 , wherein the process steps are carried out in an open mold, and in a first step the decorative layer is inserted into the open mold or produced therein and the further steps then follow in the open mold.
8 . The method of claim 1 , wherein the expanded foam layer is applied by spraying.
9 . The method of claim 1 , wherein a reactive foamed expanded polyurethane foam raw material is applied to form a soft polyurethane foam or a semi-rigid polyurethane foam as the expanded foam layer.
10 . The method of claim 9 , wherein nitrogen is used as the blowing agent for foaming the foam raw material.
11 . The method of claim 9 , wherein polyol and isocyanate components are mixed to produce a reaction mass for producing the foam raw material, and the blowing agent is introduced into the reaction mass before and/or during the mixing process or into the polyol component and/or the isocyanate component used to produce the reaction mass.
12 . The method of claim 9 , wherein the foam raw material to be applied and foamed by the blowing agent is anhydrous or at least mostly anhydrous.
13 . The method of claim 1 , wherein the support substrate has at least one opening, and the lining part is produced with a predetermined breaking point to create an opening through the lining part.
14 . The method of claim 1 , wherein the support substrate is permeable for the expanded foam layer, and wherein foam material of the expanded foam layer is introduced into the support substrate by the positioning of the support substrate relative to the decorative layer with interposition of the expanded foam layer.
15 . The method of claim 14 , wherein a fiber mat is used as the support substrate.
16 . A lining part comprising a support substrate, a flexible decorative layer, and a foam layer therebetween, the lining part produced according to the method of claim 1 , wherein the lining part has a homogeneous hardness with respect to the foam layer over a planar extension thereof regardless of possible varying gap dimensions being present between the decorative layer and the support substrate.
17 . The lining part of claim 16 , wherein the foam layer is formed by an expanded polyurethane foam.
18 . The lining part of claim 16 , wherein the lining part has at least one opening.
19 . The lining part of claim 16 , further comprising a second foam layer arranged between the first foam layer and the decorative layer and/or the support substrate, which has a different hardness compared to the first foam layer.
20 . The lining part of claim 16 , wherein the lining part is an interior lining part for a vehicle.

Description

BACKGROUND The disclosure relates to a method for producing a lining part, in particular for the interior of a vehicle, wherein a support substrate is positioned opposite a flexible decorative layer with the interposition of a foam coating and the support substrate is adhesively connected thereto. Also described is an interior lining part produced using this method, wherein the raw compound used to form the foam layer, foamed with a gas as a physical blowing agent, is applied to the rear face of the decorative layer and/or the side of the support substrate facing the decorative layer as a reactive expanded foam raw compound. Such lining parts are found as interior lining parts in motor vehicles, for example, in the form of instrument panel covers, door panels, glove compartments and the like. Such lining parts are also used outdoors on boats, for example. Such lining parts include a rigid support substrate, which is attached to the vehicle chassis. The support substrate can be used to support installation or attachment parts, for example electrical/electronic units. Such a support substrate is typically a plastic injection molded part made of PP or ABS. The visible side of such an interior lining part is formed by a decorative layer. The decorative layer is flexible and can also have elastic properties, especially if it is a plastic layer, for example made of polyurethane. In order to provide the lining part with a so-called soft-touch property, there is an elastic soft foam layer between the decorative layer and the support layer. Generally, the thickness of such a foam layer is only a few millimeters, typically 3 to 8 mm. The feel provided by the foam layer, and therefore its hardness, is largely defined by the choice of the foam raw compound, the degree of expansion thereof and the density of the foam layer. In a classic back-foaming process to produce such a lining part, the decorative layer is inserted into an open, multi-part mold or created on one half of the mold by injecting a plastic compound. A reactive foam-forming raw compound is then applied to the back of the decorative layer. The mold is then closed, with the other half of the tool carrying the support substrate. In the closed form, a predefined gap is left between the support substrate and the decorative layer. The reactive foam-forming raw compound contains a chemical blowing agent. This is typically water. As a result of the reaction that takes place between the components that form the foam—in the case of polyurethane these are the polyol and isocyanate components—the raw compound is polymerized and at the same time foamed due to an isocyanate-water reaction that releases gas. At the end of the cross-linking process, the foam layer is formed between the decorative layer and the support substrate. At the same time, the cross-linking process is used so that the foam is adhesively bonded to both the decorative layer and the support substrate. Adhesion promoters can support the adhesive bonding of the foam layer to the decorative layer and the support substrate. Soft polyurethane foams with densities between 150-200 kg/m3 are typically used to form such foam layers, for example for a vehicle interior lining part. What should be taken into account with this manufacturing process is that quite high pressures and temperatures are sometimes generated within the mold during chemical foaming and the accompanying polymerization. This not only places high demands on the molds or mold parts used for these purposes. It should also be noted that the decorative layer must have a quality that can withstand these influences, in particular the temperatures, even if there may be different temperature distributions in the mold. The latter must not result in a different appearance depending on the temperature on the visible side of the decorative layer. If materials that have openings are used as decorative layers in this process, foam breakthroughs can occur due to the pressures of 2-5 bar in such a mold, where foam is pressed onto the visible side of the decorative layer. Therefore, when using such materials to provide the decorative layer, it is sometimes necessary to carry out complex sealing measures before applying the reactive, not yet expanded raw compound. DE 10 2011 005 343 A1 relates a method for producing such a lining part in an open mold. This process uses a low-energy foam system, i.e. a foam system that does not cause any major pressures. The physical state of the reactive foam raw compound applied to the rear face of the decorative layer is selected so that it does not flow after coating. This is done in view of the fact that the foam raw compound does not penetrate into openings in the decorative layer. If a connection of the support substrate is desired without additional adhesion promoters or other adhesives, it can be pressed into the surface of the foam raw compound when the foaming process has ended or at least substantially ended. Howe