FR2871119A1 - Electrically-heated moulded foam component, especially for motor vehicle seat, has heating element of braided or woven carbon fibre textile structure - Google Patents

Abstract

The moulded foam component for a vehicle seat (8) comprising an elastic body (16) with a covering layer (10) has a heating element (12) made from a woven carbon fibre textile structure with separating layers (14, 20, 22) between it and the upper surface of the elastic body. The moulded foam component for a vehicle seat (8) comprising an elastic body (16) with a covering layer (10) has a heating element (12) made from a woven carbon fibre textile structure with separating layers (14, 20, 22) between it and the upper surface of the elastic body. At least one of the separating layers (14) is of a hot-melt adhesive, and another (20) is of a textile or perforated film that decomposes during or after the injection of the moulded foam component. The other separating layer (22) is of a gel.

Description

The present invention relates to a molded element made of heated foam

  electrically, essentially for a seating element of a vehicle interior equipment, and the corresponding embodiment method.

  A molded foam element such as an electrically heated seat element of a vehicle interior equipment should be able to limit itself to a low power consumption, therefore the heating element should be fitted as close as possible to the surface upper part of the molded foam element.

  On the other hand, the heating element of a seat element must not form a relief under the covering and remain undetectable to the touch and if possible, it must have an effect uniformly over the entire surface of the molded foam element. These requirements can be optimized by the implementation of thermal conduction means made of textile material, essentially with thermal conduction means made with thin mono or multifibre carbon fiber filaments. The carbon fibers may be braided shapes and / or a twisted and / or woven textile structure (known as carbotex).

  The molded foam elements, for example the seat elements for vehicle interior equipment, are generally made in stages in which the molded foam element and the heating element, generally flat, attached to a support made of textile material. , are made separately and connected in a second step to each other by a partial bonding or on the entire surface.

  DE 3 725 408 A1 discloses a method for manufacturing a heated vehicle seat in which a heating element is adapted by embedding and gluing on a layer of a molded foam member, then covered with a covering fabric .

  WO 01/19220 A1 discloses a method of applying thermal conduction means to a surface, for example an upper surface of a vehicle seat by means of an intermediate and temporary glue support layer.

  The intermediate support layer after sizing of the heat conduction means will be dissociated from the upper surface. In this case also, the seat of the vehicle will be made separately from the heating element.

  Basically, the molded foam element will be made by adding synthetic foam, for example polyurethane material (PUR) using a template on a coating layer, using this template in negative form or counterprint. The heating elements lend themselves to integration during this manufacturing step in that they follow the negative shape of the inner surface, the coating layer, respectively as for example the coating material with subsequent application of the foam. Such an adaptation of the heating elements leads to a simplification of the method of producing heated mounting elements.

  The use of braided carbon fibers and / or textiles to manufacture the heating elements according to the method described is not feasible in the current state of the art. The direct rear foaming process of the multi-filament carbon fibers leads to a stiffening of the latter, since by capillarity the foam penetrates the structure thus created. This penetration of foam surrounding the filaments of the fibers, hardening them. The elasticity of these multi-filament heating elements is substantially reduced so that a long-term mechanical load on the heating element, particularly on the vehicle seats, leaves a mark, this type of process is not feasible in foaming processes of the state of the art, the material called Carbotex has not been used.

  One of the objects of the present invention is that an electrically heated foam molded element, substantially a seating element of a vehicle interior equipment and the method for the corresponding embodiment can be proposed making it possible to use in the form of braid and / or textile of a heating element made of carbon fibers, especially multi-filaments by rear foaming. Therefore, the realization of the molded foam body and the inclusion of the heating element made of braided material and / or textile material are feasible at one time, while fully preserving the structure of the element with a heating element .

  This object will be achieved with an element and / or a method according to the content of the independent claims. The advantageous features of the invention emerge from the dependent claims.

  An electrically heated foam molded element, essentially for a seating element of a vehicle interior equipment according to claim 1, is basically and according to the invention the foam molded element may be any of the imaginable parts of the invention. a vehicle that is likely to be provided with a heating device. The molded foam element will not necessarily have a flexible structure and may be relatively rigid. Such a foam molded element electric heater is provided essentially for padded seats for vehicle seats. These elements may, however, be folders and armrests of vehicle seats.

  The coating layer may be in particular textile coating, however other materials are provided and possible for this application, such as microfibers, the court, perforated leather, etc. According to the invention, between the upper surface of the foam molded body and the coating layer is adapted a heating element of braided material and / or multi-fiber woven fabric structure distributed over the entire surface. This surface element is flat, made of a thin fabric, electrically conductive, preferably carbon fiber called Carbotex.

  According to the present invention, a non-adherent release layer which avoids capillarity with the heating structure preventing bonding with the molded foam, preventing amalgam by penetration of the foam into the heating structure.

  According to a preferred embodiment of the present invention, at least one of the separation strains comprises molten glue, such as for example comprising polyurethane material (PUR).

  The molten glue can be distributed around the various heating elements with multiple filaments. Alternatively, the fusion glue may be applied as a grid pattern of textile or fleece padded on the layer of the heating element. According to the invention, a carrier surface covering is possible, in that the fibrous and heating elements, especially the multi-filament carbon fiber son fixed in their positioning thereby simplifying their transport and assembly. In addition, it allows the fixing of the heating element in the hollow or negative form in which the coating layer is located, for example a textile coating before application of the foam.

  To do this, a precise positioning of the heating element in the molding element of the foam is obtained. In addition, the fabric layer will be able to bond the heating element and the foam molding member by the melt glue. In addition, the molten glue will be activated thermally during or after the foam application process, for example by means of a high temperature of the foam during its application or after application of a sufficiently high voltage on the foam. 'heating element. Cooling after bonding will be established. The melting layer of the glue will not be more visible and / or noticeable on the molded foam element.

  According to the present invention, the layer described above may serve as a protective layer, in that it prevents the penetration of the foam mass during its application in the carbon fiber texture. As a result, the foam will not be able to penetrate the various carbon fiber filaments and harden between them, thus avoiding a brittle stiffening of the fibers. The elasticity of the carbon fiber weave is preserved in this way ensuring the preservation of the heating element mechanical effects, this over time.

  Thus, at least: a separation layer is distributed over the entire surface and has a textile structure or in the form of a film; one of the separation layers is present in the form of a film; the layer in the form of a film comprises polyurethane.

  According to the present invention, for its embodiment the separation layer film may be polyurethane material or a polyurethane base (PUR). The film alone as a separating layer or in addition to a layer of fusion glue described may be added to increase the protective effect of the heating element during its manufacture. The film material may be perforated and / or perforated for ventilation and thereby not affect the foam molded element by negative reactions.

  The perforation after drilling is advantageously carried out in such a way that the mass of foam is completely impermeable. In a preferred embodiment of the present invention, the film material will be such that, during the step or after the step of injecting the molded foam element, for example during the curing of the foam, decomposes avoiding negative reactions on the electrically heated foam molded element. There will be no influence on the natural ventilation (passage of air) essentially in the case of the seat of a vehicle, preserving a good comfort of the seat.

  The rigidity and phonic effects of film materials would no longer exist in a complete molded foam element, thus allowing them to be attached to a glue-bonding adhesive backing layer. Alternatively, it would be possible to first adapt a layer of gel, especially PUR polyurethane material (called Technogel) on which we can then position and fix the structure of heating elements. Thus, at least one of the separation layers consists of a material in gel form. Other intermediate separation layers, for example of film-shaped material, essentially made of polyurethane material film or in the form of a gel, essentially a polyurethane gel (PUR) may be placed in the negative imprint of the template, adapted on the coating layer or gel and / or the heating element. The heating body and / or one of the melt adhesive separation layers and / or one of the film-like separating layers are made of a gel material.

  When all the layers are disposed in the negative imprint, the foam will be applied, for example a polyurethane foam (PUR) which will be injected into the negative impression which will subsequently harden forming a molded body. resistant three-dimensional foam.

  A film placed in the assembly may be of a material such that it will decompose during or after the injection of the foam. A layer of fusion adhesive may, either by thermal effect during the injection of the foam, or by means of a tensioning of the heating element after the injection or during the curing of the foam, establish a connection by bonding between the heating element and the foam body.

  Preferably, the collage will be done after the decomposition of the film. The bonding will have a finish such that it will not be visible and / or detectable on the molded foam element.

  An electrically heated foam molded element such as for example a seat element of a vehicle interior equipment according to the present invention made for example of a carbon fiber texture, which according to the invention will be arranged in a molded foam element will optimally cover the main elements.

  Between the coating layer, respectively the foam molded coating and the heating element, there is no other layer that could generate the heat transfer. The electrode tracks are distributed in a regular and close manner over the entire surface to be heated so that there is a uniformly distributed heating of the upper surface (characteristic of the so-called Carbotex material). The good characteristics also concerning the elasticity and the permanence of the mechanical properties and the heating structure are preserved. The air permeability and elasticity of the electrically heated foam molded element are real on the finished product.

  The present invention makes it possible to use a braided and / or woven heating element made of textile material, for example multi-filament heating elements, essentially made of carbon, in the injection technique and thus leads to an obvious simplification and improvement. electric heating elements in the form of foam-mounted elements for interior equipment of vehicles and their production. This corresponds to a huge enlargement of the market for the so-called Carbotex material or materials having a similar structure which are substantially unfavorable to the penetration of the injected foam.

  The present invention further relates to a method for producing an electrically heated foam molded member with a resilient body adapted, at least in part, with a coating layer to an upper surface exterior to the upper surface of the body and the coating layer distributed over the entire surface of a braided heating element and / or woven (textile) texture, in particular a molded foam element.

  According to other characteristics of the process: at least one separation layer will be in the form of a film; the material in the form of a film is polyurethane; the film is perforated or perforated; the film will break down during or after the injection of the foam; at least one separation layer will be in the form of a gel; the heating element and / or a fusion adhesive separation layer and / or a separation layer is coated with a material in the form of a gel; the material in gel form contains polyurethane.

  The invention will be described hereinafter with the aid of exemplary embodiments taking into account the appended drawings in which: FIG. 1 is a sectional view according to the invention of the upper outer surface of an electrically heated vehicle seat and foam, shown in a simplified embodiment during the process of the embodiment in an imprinted template or negative form; FIG. 2 is a sectional view according to the invention of the upper outer surface of an electrically heated vehicle seat and foam, also shown in a simplified embodiment during the implementation of the method in an imprint template or negative form FIG. 1 according to the invention represents the production of an electrically heated foam molded element 8 of the interior equipment of a vehicle. The sectional view shows the layering of such an element. A textile coating 10 disposed on the outer face of the seat member 8 is directly adapted to the inner face of the negative impression template 18. Directly below is disposed a thermal conductive textile layer consisting of a fibrous fiber texture. carbon called Carbotex. On the foam body 16, on the thermal conductive layer side 12, there is a carrier or separator layer in the form of a textile material or a fusion adhesive film 14 which serves as a protection between the heating structure and the thermally conductive multi-filament fibers. 12 during the injection process. The body of the molded foam member 16 is made of a synthetic foam, for example polyurethane. This will be shaped by the negative imprint 18 of the template in which will be placed the textile coating material 10, the heating element 12, and a melt adhesive 14, followed by a foam injection. The drawing represents the moment directly after the injection of foam where all the layers are still visible.

  Fig. 2 is an alternative cross-section showing a more complex embodiment of the present invention. The embodiment here representing the construction of the electrically heated foam molded element 8 is composed of the exterior to the interior of the following layers: - a textile coating 10; a thermal conductive layer made of woven carbon fibers (Carbotex material); a separator layer or carrier of fusion adhesive 14 which serves as a protective layer in that it prevents the penetration of the injected foam into the heating structure or thermal conductive layer 12 during the injection; a layer in the form of a polyurethane film which provides additional protection with respect to the penetration of the injected foam into the so-called Carbotex texture; a layer of polyurethane gel 22 which isolates the synthetic foam material 16 from the heating structure 12, which furthermore has an anti-corrosion effect increasing the life of the seat element 8.

  The body 16 of the molded foam element 8 is composed of a synthetic foam, for example polyurethane material. This is injected into a negative impression jig 18 in which a textile coating material 10, a heating element 12, a melt adhesive 14 in the form of a textile material or a film, a PUR film 20 and polyurethane gel known as PUR 22. The conductive heating layer 12 can, via the melt-glue layer 14, be accurately positioned as well as the polyurethane film PUR 20. During the injection and hardening of the material synthetic film, respectively the film 20 can be decomposed so as to avoid the disadvantages affecting the characteristics of the finished product, the molded foam element 8 electrically heatable, such as ventilation or stiffness. The drawing corresponds to the moment when, after the injection, all the layers are still visible.

  The elements described, the characteristics of the drawings and claims may be, as desired, made in different combinations for carrying out the invention.

  The invention is not limited to the embodiments described. Several variants and developments that may be of the invention are possible and therefore fall within the scope of this protection.

  Reference signs 8 electrically heated foam molded element 25 textile coating 12 thermal conductive textile layer 14 textile material or fusion adhesive film 16 foam body of the molded foam element 18 negative impression layer in the form of polyurethane film 22 Technogel polyurethane gel layer The reference signs inserted after the technical features mentioned in the claims are intended only to facilitate understanding of the latter and in no way limit its scope.

Claims (1)

11 CLAIMS   An electrically heated foam molded element, essentially for a seating element of a vehicle interior equipment (8), having at least partly an elastic body (16) with a coating layer (10) on an upper surface and disposed between the top surface of the coating layer, distributed over the entire surface of a heating element (12) of braided material and / or textile structure, characterized in that the distributed surface of the heating element (12) ) formed of braids and / or woven fabric structure and the upper surface of the body of the molded foam element (16), at least during the injection sequence, are separated by a separating layer (14, 20, 22 ).   2. Element according to claim 1, characterized in that the heating element (12) made of braided material and / or woven fabric is made of carbon fibers.   3. Element according to one of claims 1 or 2, characterized in that at least one of the separation layers (14) comprises melt adhesive.   4. Element according to claim 3, characterized in that the melt adhesive 14 comprises polyurethane.   5. Element according to one of claims 3 or 4, characterized in that at least one separating layer (14) is in textile structure or in film form.   6. Element according to one of the preceding claims, characterized in that at least one of the separation layers (20) is present in film form.   Element according to claim 6, characterized in that the film-like layer (20) comprises polyurethane.   8. Element according to one of claims 6 or 7, characterized in that the film material is, or perforated, or hole.   9. Element according to one of claims 6 to 8, characterized in that the film material decomposes during or after the injection step of the molded foam element.   10. Element according to one of the preceding claims, characterized in that at least one of the separation layers (22) is constituted by a material in gel form.   Element according to one of Claims 1 to 9, characterized in that the heating element (12) and / or one of the fusion adhesive separation layers (14) and / or one of the separation layers in the form of film (20) is taken from a gel material.   12. Element according to one of claims 10 or 11, characterized in that the gel 15 is a polyurethane gel.   A process for producing an electrically heated foam molded member with a resilient body (16) adapted at least in part with a coating layer (10) at an upper surface exterior to the upper surface of the body and the coating layer distributed over the entire surface of a braided heating element (12) and / or woven (textile) texture, in particular a molded foam element according to one of claims 1 to 12, characterized in that the element heater (12) and / or woven fabric is attached to the inner face of the coating layer (10) and subsequently provided with at least one separating layer (14, 20, 22) to which rear) an injection of synthetic materials (16) essentially of polyurethane material.   14. A method according to claim 13, characterized in that at least one separation layer (14) of the braided heating element (12) and / or in woven texture will be provided with fusion glue and will be glued to it. internal face of the coating (10) of the element (12).   15. The method of claim 14, characterized in that the injection from the rear is carried out at high temperature, that the melt adhesive in the form of a support in textile material or film form (14) of the heating element (12) will bond the foam molded element and the heating element (12).   16. The method of claim 14, characterized in that after the injection of the foam, a heating voltage is applied to the heating element (12) which will have the effect of melting the fusion glue constituted by the supports. textiles and / or in the form of existing film (14) and that will follow cooling steps during which the melt adhesive hardens promoting sizing between the molded foam element (16) and the heating element (12).   17. Method according to one of claims 13 to 16, characterized in that at least one separating layer (20) will be in the form of a film.   18. A process according to claim 17, characterized in that the film material is polyurethane (20).   19. Method according to one of claims 17 or 18, characterized in that the film is perforated or perforated.   20. Method according to one of claims 17 to 19, characterized in that the film will decompose during or after the injection of the foam.   21. Method according to one of claims 13 to 20, characterized in that at least one separating layer (22) will be in gel form.   Method according to one of Claims 13 to 20, characterized in that the heating element (12) and / or a fusion adhesive separation layer (14) and / or a separating layer (20) is coated of a material in gel form.   23. Method according to one of claims 21 or 22, characterized in that the material in gel form contains polyurethane.