Leather-layer system forming a covering for a foam body

Abstract

The invention relates to a leather-layer system (4) forming a coating (2b; 3b; 15b) for a foam body (2a; 3a; 15b), with a leather layer (5), a foam layer (7), and an intermediate adhesive layer (6) for the surface bonding of the foam layer (7) with the leather layer (5), the foam layer (7) being oriented towards an inner side (4a) and the leather layer (5) being oriented towards an outer side (4b) of the leather-layer system (4), and the foam body (2a; 3a; 15a) being formed by a foam-in-place process within a recess (11) defined by the inner side (4a) of the leather-layer system (4). According to the invention, the foam layer (7) is composed of ethylene-propylene-diene rubber and has a semi-closed cell structure. [Figure 2a]

Description

Title of the invention: Leather-layer system forming a coating for a foam body

[0001] The invention relates to a leather-layer system forming a coating for a foam body, in particular as an integral part of a padded element in a vehicle, as well as a padded element and a method for its manufacture.

[0002] In the field of vehicle interiors, a number of upholstered elements are known that consist of a foam core, which is notably covered with a layer of leather. In this context, it is common to use laminated leather layers to make the leather layer stiffer and thus optimize it for subsequent processing and in terms of its durability. The upholstery therefore consists of a leather-layer system.

[0003] The foam body is, for example, shaped in the form of the respective upholstered element, for example, a seat surface, or a backrest, headrest, or armrest of a vehicle seat, and the leather layer system is adapted to the external shape of the foam body. For this purpose, a process known as foam-in-place (FIP) can be used, in which the leather layer system is inserted into an FIP mold, the FIP mold imitating the contour of the upholstered element to be produced, for example, the seat surface, backrest, headrest, or armrest. Once the leather layer system is placed on the surface of the FIP mold, the leather layer system defines a recess with its inner side. As part of the FIP process, a foam is introduced into this recess and then solidified, so that a solid foam body forms in the recess.This is completely surrounded by the leather layer system, so the leather layer system acts as a covering.

[0004] A drawback of FIP processes operating in this way is that a leather-layer system consisting of a conventionally laminated leather layer can be attacked by the injected foam. This is because the injected foam reacts directly with the leather layer, attacking it and / or exerting a force on the leather layer during solidification, thereby densifying it. As a result, the leather layer can be negatively affected during the FIP process. Furthermore, in the case of a laminated leather layer, it cannot always be prevented that the leather layer will develop creases, as the laminated leather layer can slip relative to the substrate, i.e., the foam core, particularly in the event of deformation. In addition, in conventional lamination processes, the leather layer may become very stiff, which reduces comfort when used as upholstery in padded items.

[0005] To prevent reactive attack on the leather layer by the foam injected during the FIP process, protective layers are known, which, however, due to their rigidity, cannot prevent the leather from creasing. Furthermore, these layers are not elastically flexible, thus allowing for a reduced capacity to adapt to the underlying foam body.

[0006] According to CA 2 597 280 A1, leather layer systems with an inwardly facing PU foam layer are known, which consists of either open-cell or closed-cell foam. However, due to their structure, they cannot adequately protect the leather layer system during use in a FIP process, nor can they prevent the formation of creases during deformation.

[0007] Other leather layer systems with additional foam layers are known for example from CN 202213244 U, CN 103029402 A, US 20170259126 Al and JP 2018108685 A. These also cannot help to eliminate the disadvantages mentioned above.

[0008] The object of the invention is therefore to provide a leather-layered covering system for a foam body, which prevents alteration of the leather's quality due to the formation of the foam body and the appearance of creases. The object of the invention is also to provide a padded element and a method for manufacturing it.

[0009] This goal is achieved by:

[0010] a leather-layer system forming a coating for a foam body, having a leather layer, a foam layer and an intermediate adhesive layer for the surface bonding of the foam layer with the leather layer, the foam layer being turned towards an inner side and the leather layer towards an outer side of the leather-layer system and the foam body being formed by a foam-in-place process inside a recess defined by the inner side of the leather-layer system, the foam layer being made of ethylene-propylene-diene rubber and having a semi-closed cell structure;

[0011] a padded element with a foam body and a leather layer system forming a covering for the foam body, the leather layer system having a leather layer, a foam layer and an intermediate adhesive layer for surface bonding the foam layer with the leather layer,

[0012] the foam layer being turned towards an inner side and the leather layer towards an outer side of the leather-layer system and the foam body being formed by a foam-in-place process inside a recess defined by the inner side of the a leather-layer system, the foam layer being ethylene-propylene-diene rubber and exhibiting a semi-closed cell structure; and

[0013] a method for manufacturing a padded element according to the invention, comprising at least the following steps:

[0014] - supply of a FIP mold and a leather layer system according to the invention;

[0015] - insertion of the leather-layer system into the FIP mold such that the leather layer system rests surface-wise with its outer side on the FIP mold and a recess is defined by the inner side of the leather layer system;

[0016] - injection of a foam into the formed cavity; and

[0017] - solidification of the injected foam to form a formed foam body by a FIP process inside the recess, so that the solidified foam body rests surface-wise on the inner side of the leather-layer system.

[0018] According to the invention, the foam layer of a leather-layer system is therefore made of ethylene-propylene-diene rubber (EPDM) and has a semi-closed-cell structure. In other words, the EPDM foam layer is formed from a mixture of open-cell EPDM foam and closed-cell EPDM foam. The leather-layer system serves here as a covering for a foam body, for example, as an integral part of an upholstered element, particularly in a vehicle.

[0019] By forming the foam layer in a semi-closed-cell EPDM structure, the properties of open-cell and closed-cell foams are advantageously combined, so that, according to the invention, a particularly elastic foam layer is formed that is both breathable and waterproof. Cavities form in the foam layer due to the proportion of open-cell foam. These cavities can be compressed during or after the formation of the foam body, which occurs during a foam-in-place (FIP) process, and thereby close at least partially. As a result, the foam layer can act as a barrier layer during the FIP process, compressing during the formation of the foam body and thus absorbing the forces acting during the FIP process. Consequently, the leather layer can advantageously be protected, and compaction can thus be avoided.Furthermore, the foam layer can serve as a barrier or protective layer so that the PU foam injected during the FIP process does not attack the leather layer from the inside.

[0020] The FIP process for forming the foam body is thus, according to the invention, carried out such that the leather layer system is inserted into the FIP mold in such a way that the leather layer system rests on the surface with con The outer side of the FIP mold is formed, and a recess is defined by the inner side of the leather-layered system. Foam, preferably PU foam, is then injected into this recess. This foam is then solidified to form a foam body through a foam-in-place process within the recess, so that the solidified foam body rests on the inner side of the leather-layered system, thus forming a padded element.

[0021] It is thus advantageously achieved that the inwardly facing foam layer serves as a barrier layer, or protective layer, for the FIP process in order to protect the leather layer accordingly.

[0022] Furthermore, the layered configuration with the semi-closed-cell EPDM foam layer has the advantage that the leather layer system is less rigid and therefore offers greater comfort. In addition, the formation of creases (loose grain defect) can be avoided in the event of deformation of the foam layer or the entire leather layer system. This is because the EPDM foam layer, due to its semi-closed-cell structure, does not experience a significant reduction in thickness, for example, between 1 mm and 5 mm depending on the application, in the event of deformation. The leather layer, bonded to the foam layer by means of a surface adhesive layer, thus does not undergo shrinkage or compression in the event of deformation – during the FIP process or during use – so that the formation of creases can be avoided.

[0023] Preferably, the adhesive layer is also provided to be formed by a hot melt adhesive. As a result, the leather layer can be securely bonded to the foam layer, for example during a lamination process, so that the leather-layer system can be held firmly together when a load is applied during use.

[0024] Preferably, the leather-layer system is further provided that it completely envelops the foam body to form a full covering. Consequently, a padded element is formed, which is completely enveloped on the outside by a layer of leather and thus offers the advantages of the leather-layer system according to the invention. However, it can also be provided that only relevant parts of the padded element are enveloped by the leather-layer system according to the invention. For example, in the case of a headrest, the area on which the occupant's head rests may be the only part covered by the leather-layer system according to the invention in order to provide increased comfort. Conversely, on the rear side of the headrest, a normal leather-layer system may be used. This applies respectively to other vehicle components.

[0025] According to a preferred additional feature, the foam layer is provided to have a thickness of between 1 mm and 5 mm. The barrier and protective effect according to the invention, this can thus be achieved very efficiently without the leather layer system becoming too thick.

[0026] Preferably, the foam layer is further provided to be differentiated from the coated foam body, the foam layer being bonded or capable of being bonded to the foam body at least in certain areas. Accordingly, the foam body formed during the foam-in-place process can be formed from any type of foam, for example, an open-cell PU foam, and the foam layer can serve as an additional foam layer between the foam body and the leather layer as a barrier and protective layer as described. By bonding the foam layer to the leather layer, the latter can be easily positioned during the foam-in-place process by means of a corresponding arrangement in the FIP mold and can also advantageously be bonded to the foam body.This prevents the leather-layer system from lifting above the foam body, thus increasing comfort or preventing the formation of creases.

[0027] Preferably, a foam insert is further provided to be disposed at least in zones on the ethylene-propylene-diene rubber foam layer, which is also made of ethylene-propylene-diene rubber and has a semi-closed cellular structure. The foam insert can be prefabricated and then bonded to the inner side of the leather-layer system according to the invention, so that two superimposed layers of ethylene-propylene-diene rubber are formed.

[0028] The advantage, according to the invention, of increased comfort due to the particularly high elasticity of the padded element in the two superimposed layers of ethylene-propylene-diene rubber can thus be amplified. If the additional foam insert is, for example, placed in a headrest area on the headrest, the occupant's comfort increases. Simultaneously, this foam insert also acts as a barrier layer, which is also both breathable and waterproof.

[0029] The dimensions of the additional foam insert can be selected here according to the implementation. In addition to its use in a headrest area of ​​the headrest, the foam insert can also be used on other upholstered components of the vehicle to increase occupant comfort, for example on the seat, armrest or backrest.

[0030] In the same way as an additional application of a foam insert on the foam layer, it may also be provided that the foam layer of the leather layer system according to the invention be made thicker in areas in order to obtain the same effect.

[0031] According to the invention, a padded element with a foam body and a leather-layer system forming a covering for the foam body is also provided, the system a leather layer comprising a leather layer, a foam layer and an intermediate adhesive layer for surface bonding of the foam layer with the leather layer, The foam layer is oriented towards an inner side and the leather layer towards an outer side of the leather-layer system, and the foam body is formed by a foam-in-place process within a recess defined by the inner side of the leather-layer system. The foam layer is made of ethylene-propylene-diene rubber and has a semi-closed cell structure. Preferably, the upholstered element is a vehicle component, in particular a seat, backrest, headrest, or armrest of a vehicle seat, or other optional upholstered covering of the vehicle interior, for example, in the headliner, on the dashboard, or similar surfaces. The upholstered elements may also be provided in certain areas with an additional foam insert as described above.

[0032] The invention is explained in more detail below based on embodiment examples. These examples are:

[0033] [Fig-1] is a schematic view of a vehicle seat;

[0034] [Fig.2a], 2b show detailed views of a leather-layered covering system for a foam body for use in the vehicle seat of [Fig.1];

[0035] [Fig.2c] shows another embodiment of the leather layer system with an additional foam insert;

[0036] [Fig.3] represents a flow diagram of the process according to the invention; and

[0037] [Fig.4] is a schematic view of a FIP mold.

[0038] In [Fig. 1], a vehicle seat 1 is shown with a seat 2, a backrest 3 and a headrest 15. The seat 2, the backrest 3, and the headrest 15 are each designed as upholstered elements 50 within the meaning of the invention and each also have a correspondingly shaped foam body 2a, 3a, 15a. In so doing, the foam body 2a, 3a, 15a defines the shape of the seat 2, the backrest 3, or the headrest 15. The foam bodies 2a, 3a, 15a are respectively completely enveloped by a covering 2b, 3b, 15b, which is adapted, at least in certain areas, to the shape of the underlying foam body 2a, 3a, 15a. The coverings 2b, 3b, 15b are each formed of a leather layer system 4 according to the invention, shown in detailed cross-section in [Fig. 2a] and 2b.

[0039] As such, the leather-layer system 4 has a leather layer 5, an adhesive layer 6, preferably made of a hot-melt adhesive, and a foam layer 7. The adhesive layer 6 serves here to bond the two outer layers 5 and 7. This leather-layer system 4 rests with its inner side 4a in such a way surface on the respective foam body 2a; 3a; 15a and is appropriately connected thereto. An outer side 4b of the leather-layer system 4 is, in the vehicle seat 1 according to [Fig. 1], in the respective area in contact with an occupant or points towards the vehicle passenger compartment.

[0040] According to the invention, the foam layer 7 is formed of a semi-closed cell foam, the foam used being made of ethylene-propylene-diene rubber (EPDM). Semi-closed cell foam is understood to mean a foam that is formed from a mixture of an open-cell foam and a closed-cell foam.

[0041] This combines the properties of both cellular structures (open-cell and closed-cell), thereby forming a particularly elastic foam layer 7 that is both breathable and waterproof. Due to the proportion of open-cell foam, cavities 8 are formed in the foam layer 7. These cavities are compressed during or after the injection of foam, particularly PU foam, into the coating 2b; 3b; 15b for the formation of the foam body 2a; 3a; 15a during a process known as foam-in-place (FIP) and thus close at least partially. Consequently, the foam layer 7 can act as a barrier layer during the FIP process, sagging during the formation of the foam body 2a; 3a; 15a and thus absorbing the forces acting during the FIP process. The leather layer 5 can thus be protected.Furthermore, the foam layer 7 acts as a barrier or protective layer so that the PU foam injected during the FIP process does not attack the leather layer 5 from the inside.

[0042] The FIP process for forming the respective foam body 2a; 3a; 15a proceeds as shown in [Fig. 3], such that the leather layer system 4 is placed in a first step 11 with its outer side 4b surface-mounted on an FIP mold 10 schematically represented in [Fig. 4], and is appropriately fixed thereto, so that the leather layer system 4 completely covers the FIP mold 10. The FIP mold 10 reproduces the shape of the upholstered element 50, here the seat 2, the backrest 3, or the headrest 15, so that the leather layer system 4 inserted therein follows the desired profile of the respective upholstered element 50 (2; 3; 15). The upholstered element 50 can also be an armrest or another upholstered element in a vehicle interior. The foam layer 7 of the leather layer system 4 is turned towards an interior space of the FIP mold 10 and delimits a recess 11 there.

[0043] In a second step, during a second step E2, a foam, for example PU foam, is then injected into this recess 11 so as to fill it completely and is solidified during a third step E3, preferably under the action of heat. A solid foam body 2a; 3a; 15a is thus formed in the recess 11, resting on the surface layer of foam 7 on the inner sides 4a of the leather layer system 4 and substantially takes up the profile of the FIP mold 10 and therefore of the respective padded element 50 (2; 3; 15).

[0044] The padded element 50 (2; 3; 15) produced with this process thus presents the corresponding desired shape and directly a leather layer system 4 forming a covering 2b; 3b; 15b around the solidified foam body 2a; 3a; 15a. During the FIP process, the foam layer 7 can, at least in zones, also bond with the solidified foam body 2a; 3b; 15b.

[0045] Due to the described elasticity of the foam layer 7, ensured by the semi-closed cell structure or the use of EPDM, the foam layer 7 can serve as a barrier or protective layer during this FIP process, as described above. Simultaneously, the leather layer system 4, forming a coating 2b; 3b; 15b of the foam body 2a; 3a; 15a, results in reduced stiffness and prevents the formation of creases (loose grain defect) during deformation of the foam layer 7 or the entire leather layer system 4. This is because the foam layer 7, due to its semi-closed cell structure, does not experience a significant reduction in thickness E (see [Fig. 2b]), for example, between 1 mm and 5 mm depending on the application, in the event of deformation.The leather layer 5, bonded to the foam layer 7 by means of the adhesive layer 6 on its surface, does not undergo shrinkage or compression in the event of deformation - during the FIP process or during use, so that the formation of creases can be avoided.

[0046] Furthermore, as shown in [Fig. 2c], a foam insert 20 may be provided in the padded element 50, for example in the headrest 15, on the inner side 4a of the upholstery 15b, which is implemented at least in certain areas as a leather-layer system 4. The foam insert 20 rests on the surface of the ethylene-propylene-diene rubber foam layer 7 and is also made of ethylene-propylene-diene rubber. The foam insert 20 may be prefabricated accordingly and bonded to the inner side 4a of the leather-layer system 4 according to the invention, so that two superimposed layers of ethylene-propylene-diene rubber are formed.

[0047] The advantage, according to the invention, of increased comfort due to the particularly high elasticity of the padded element 50; 15 at the level of the two superimposed layers 7, 20 of ethylene-propylene-diene rubber can thus be amplified. If the additional foam insert 20 is arranged as illustrated in a headrest area 15c on the headrest 15, the occupant's comfort increases. Correspondingly, this can also be provided for other vehicle components, for example, selected areas of the seat 2 and / or the backrest 3 and / or an armrest, etc.

[0048] For the manufacturing process, the leather layer system 4 with the additional local foam insert 20 must be placed on the surface in the corresponding position in the FIP mold 10, so that the recess 11 is provided at this point with a bulge in the form of the foam insert 20. The foam injected into the recess 11 then rests against this foam insert 20 as well as against the foam layer 7 of the leather layer system 4, so that this foam insert 20 also acts as a barrier layer.

[0049] List of digital references

[0050] 1 vehicle seat

[0051] 2 seat

[0052] 2a foam body of the seat 2

[0053] 2b seat cover 2

[0054] 3 files

[0055] 3a foam body of the backrest 3

[0056] 3b backrest cover 3

[0057] 4 leather layer system

[0058] 4a inner side of the leather-layer system 4

[0059] 4b outer side of the leather-layer system 4

[0060] 5 layers of leather

[0061] 6 adhesive layers

[0062] 7 layers of semi-closed cell foam

[0063] 8 cavity

[0064] 10 FIP Mold

[0065] 11 obviously

[0066] 15 headrest

[0067] 15a foam body of the headrest 15

[0068] 15b headrest cover 15

[0069] 15c headrest area

[0070] 20 foam insert

[0071] 50 padded element

[0072] E thickness of the foam layer

[0073] E1, E2, E3 steps of the process according to the invention

Claims

Claims

1. Leather layer system (4) forming a covering (2b; 3b; 15b) for a foam body (2a; 3a; 15a), with a leather layer (5), a foam layer (7) and an intermediate adhesive layer (6) for surface connection of the foam layer (7) with the leather layer (5), the foam layer (7) facing an inner side (4a) and the leather layer (5) facing an outer side (4b) of the leather layer system (4) and the foam body (2a; 3a; 15a) being formed by a foam-in-place process within a recess (11) defined by the inner side (4a) of the leather layer system (4), characterized in that the foam layer (7) is made of ethylene-propylene-diene rubber and has a semi-closed cell structure.

2. Leather layer system (4) according to claim 1, characterized in that the adhesive layer (6) is formed by a hot melt adhesive.

3. Leather layer system (4) according to one of the preceding claims, characterized in that the foam layer (7) has a thickness (E) of between 1 mm and 5 mm.

4. Leather layer system (4) according to one of the preceding claims, characterized in that the foam layer (7) differs from the coated foam body (2a; 3a; 15a), the foam layer (7) being at least connected or bondable in zones with the foam body (2a; 3a; 15a).

5. Leather layer system (4) according to one of the preceding claims, characterized in that an additional foam insert (20) is applied, preferably glued, to the foam layer (7) at least in areas, the foam insert (20) being made of ethylene-propylene-diene rubber and having a semi-closed cell structure.

6. Upholstered element (50; 2; 3; 15) with a foam body (2a; 3a; 15a) and a leather layer system (4) forming a covering (2b; 3b; 15b) of the foam body (2a; 3a; 15a), the leather layer system (4) having a leather layer (5), a foam layer (7) and an intermediate adhesive layer (6) for surface bonding of the foam layer (7) to the leather layer (5), the foam layer (7) facing an inner side (4a) and the leather layer (5) facing an outer side (4b) of the leather layer system (4) and the foam body (2a; 3a; 15a) being formed by a foam-in-place process within a recess (11) defined by the inner side (4a) of the leather layer system (4), characterized in that the foam layer (7) is made of ethylene-propylene-diene rubber and has a semi-closed cell structure.

7. Upholstered element (50; 2; 3; 15) according to the preceding claim, characterized in that the upholstered element (50) is a vehicle element, in particular a seat (2) or a backrest (3) or a headrest (15) or an armrest of a vehicle seat (1), or any other upholstered covering of the interior of the vehicle, for example in the roof lining or on the dashboard.

8. Upholstered element (50; 2; 3; 15) according to claim 6 or 7, characterized in that the leather layer system (4) almost completely or at least in zones envelops the foam body (2a; 3a; 15a) to form a full covering (2b; 3b; 15b).

9. Padded element (50; 2; 3; 15) according to any one of claims 6 to 8, characterized in that the foam body (2a; 3a; 15a) is manufactured from an open-cell foam, preferably a PU foam, by the foam-in-place method.

10. Method for producing a padded element (50; 2; 3; 15) according to one of claims 6 to 9, with at least the following steps: - providing an FIP mold (10) and a leather layer system (4) according to one of claims 1 to 5; - inserting the leather layer system (4) into the FIP mold (10) in such a way that the leather layer system (4) lies surface-wise with its outer side (4b) on the FIP mold (10) and a recess is defined by the inner side (4a) of the leather layer system (4) (E1); - injecting a foam into the formed recess (E2); and - solidifying the injected foam to form a foam body (2a; 3a; 15a) formed by a foam-in-place process in the recess (11), so that the solidified foam body (2a; 3a; 15a) rests surface-wise on the inner side (4a) of the leather layer system (4) (E3).

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