GB2072088A

GB2072088A - Production of backfoamed padding supports for seats or seat backs

Info

Publication number: GB2072088A
Application number: GB8107348A
Authority: GB
Original assignee: Metzeler Schaum GmbH
Current assignee: Metzeler Schaum GmbH
Priority date: 1980-03-14
Filing date: 1981-03-09
Publication date: 1981-09-30
Also published as: FR2477966A1; NL8100676A; GB2072088B; ES256491U; SE8101256L; FR2477966B1; ES256490U; ES256490Y; ES256491Y; SE444166B; DE3009885B1; DE3009885C2

Abstract

Backfoamed padding supports for seats or seat backs are produced by a method in which a textile material covered with a film or provided with a sealing layer on the reverse side is deep drawn in a mould and is backfoamed with the formation of recesses in the foam. After deep drawing and backfoaming, the film is removed in the region of the recesses in the foam, for example by heating using heating elements located in ridges in the mould lid.

Description

SPECIFICATION Production of backfoamed padding supports for seats or seat backs This invention relates to the production of backfoamed padding supports for seats or seat backs.

It is known from German Offenlegungsschrift No.

2,404,551 to produce seats andlor seat backs for the vehicle and padded furniture industry, among other methods, in the following manner. Atextile material, for example, an extensible knitted velvet, is provided on one surface with a film and is then deep drawn in a mould, i.e. the entire surface is brought into close contact with the surface of the mould which is provided with projections andlor recesses. For this purpose, reduced pressure is generally applied to the space between the surface of the mould and the textile material. As air cannot flow into this space through the air-impermeable film, the assembly of textile material and film is closely pressed onto the surface of the mold.

In a further working step, this deep-drawn material is backfoamed with the formation of recesses, for example with a flexible polyurethane foam, so that so-called "air holes" are produced in the finished support which facilitate the circulation of air through the interior of the padding support and thereby prevent a considerable increase in temperature due to body heat, and also prevent sweat forming when sitting for comparatively long periods of time.

However, it has been found that the formation of sweat mentioned when fitting for long periods of time may not be prevented with these padding supports either, so that contact with such seats or seat backs becomes unpleasant and may even be detrimental to health.

An object of the invention is to provide padding supports with which a continuous circulation of air is ensured and an increase in temperature and sweating thereby prevented.

According to the invention there is provided a method for the production of backfoamed padding supports for seats or seat backs, in which a textile material covered with a film or provided with a sealing layer on the reverse side is deep drawn in a mould and is backfoamed with the formation of recesses in the foam, wherein after deep drawing and backfoaming, the film is removed in the region of the recesses in the foam.

The invention further provides a mould device for carrying out the process according to the invention, comprising a mould and a mould lid with ridges for producing the recesses in the foam, wherein heating elements which may be switched on after backfoaming for melting away the film are positioned below the surfaces of the ridges.

The invention also provides a backfoamed padding support for seats or seat backs, comprising a layer of foam provided with recesses, with a film covering the contact surface of the foam and with a layer of textile material on the film, wherein the film is absent in the region of the recesses in the foam.

The advantages achieved by the invention derive in particular from the fact that the air-impermeable film is removed in the region of the recesses in the foam, so that free air exchange is then automatically possible through the textile material and a build-up of air can no longer occur in the region between the body and the film. The air which is in the recesses in the foam and between the recesses is continuously exchanged by the fact that the textile material acts as a permeable membrane and body movements produce a pumping action, so that the relative air humidity is always below dew point even at a temperature which is somewhat elevated by body heat and therefore, sweating does not take place. A padding support of this type does not become noticeable unpleasant even after comparatively long use and the fatigue symptoms which are otherwise virtually unavoidable do not occur.

Although the film may in principle be removed mechanically in the region of the recesses, for example by milling, boring or grinding, it has been found to be preferable to melt the film away after backfoaming, as this process is less cost-intensive than mechanical processing. In the melting-away operation, the film is heated from the mould using a heating device. The heating device preferably has heating elements positioned in the ridges of the mould lid which may be switched on after backfoaming. In this film-removal process, the melting point of the film must naturally be below the melting point of the textile material.

The invention is described in detail below with reference to the accompanying drawing which is a section through the mould, a finished padding support and the mould lid.

As may be seen from the drawing, the inside of a mould 10 has projections 12, between which are located recesses 14. The mould lid 16 is provided with projecting ridges 18, into which are incorporated heating elements 20. The ridges 18 are positioned opposite the projections 12 in the mould 10, so that the spacing between the front face of the ridges 18 and the front face of the projections 12 is relatively small when the mould is closed.

For the production of a padding support, a textile material 28 provided on one surface with airimpermeable film 26 is positioned on the inside of the mould 10 so that the entire inside surface of the textile material 28 is in close contact with the mould 10. For this purpose, reduced pressure may be applied to the inside of the mould by suction openings (not shown). The reduced pressure causes the whole surface of the assembly of textile material 28 and film 26 to come into close contact with the inside of the mould 10 due to the air-impermeability of the film 26.

Afterthe assembly of textile material 28 and film 26 has been deep drawn in this manner on the inside of the mould 10, the mould is closed by posi tioningthe mould lid 16 on the mould 10 and optionally pressing the lid thereon. A flexible polyurethane foam is then introduced into the cavity of the mould in conventional manner, which foam particularly fills out the regions which are located between the projections 12 or ridges 18 on one hand and between the relevant recesses of the mould 10 or mould lid 16 on the other hand.

In this manner, the composite of textile material 28 and foam 26 is backfoamed, thereby producing a close, effectively adhesive join between the textile material 28 and the polyurethane foam 22.

When backfoaming is completed and the foam has substantially hardened, the heating elements 20 are switched on, so that during the resulting heating, the film 26 is melted away in the region of the front faces of the ridges 18 and thereby in the region of the recesses of the padding support.

The melting point of the film 26 must naturally be below that of the textile material 28, so that the material 28 is not damaged during heating.

When the mould is opened by raising the lid 16 and the finished padding support is removed, a padding support is then obtained as is shown in the centre of the Figure. This padding support has foam regions 22 which are joined together at the upper or lower end of the seat back or the seat, whereas in the interlying regions, recesses are provided which extend over the contact surface of the padding support and allow the airto circulate perpendicularlyto the contact surface. These recesses are indicated in the drawing by reference numeral 24 and are separated from each other by foam parts 22.

The entire contact surface of the padding support is provided with the textile material 28. However, the air-impermeable film 26 is only present on the lateral surfaces of the padding support or in the regions of the contact surface in which no recesses are provided and where, therefore, no air circulation is to take place.

The recesses 24 are covered only by the textile material 28 in the region of the recesses, so that air can circulate freely and can no longer build up.

The number, shape and spatial arrangement of the recesses 24 may be selected in dependence on various parameters, for example on the purpose of use, but also on the strain, on the type of materials selected and on similar parameters.

Thus, for example, the foam parts 22 and the recesses 24 do not have to alternate regularly with each other, but several recesses and several padding parts may be provided, while only one ortho openings are used.

Claims

1. A method for the production of backfoamed padding supports for seats or seat backs, in which a textile material covered with a film or provided with a sealing layer on the reverse side is deep drawn in a mould and is backfoamed with the formation of recesses in the foam, wherein after deep drawing and backfoaming, the film is removed in the region of the recesses in the foam.

2. A method according to claim 1, wherein removal of the film is by heating and melting it off using a heating device.

3. A method according to claim 1, wherein removal of the film is by a mechanical detachment operation.

4. A method according to claim 3, wherein the film is removed by milling, boring or grinding.

5. A method for the production of backfoamed padding supports substantially as herein described with reference to the accompanying drawing.

6. A mould device for carrying out the process according to claim 1, comprising a mould and a mould lid with ridges for producing the recesses in the foam, wherein heating elements which may be switched on after backfoaming for melting away the film are positioned below the surface of the ridges

7. A mould device substantially as herein described with reference to the accompanying drawing.

8. A backfoamed padding support for seats or seat backs, comprising a layer of foam provided with recesses, with a film covering the contact surface of the foam and with a layer of textile material on the film, wherein the film is absent in the region of the recesses in the foam.

9. A padding support according to claim 8, wherein the melting point of the film is below the melting point of the textile material.

10. A padding support substantially as herein described with reference to the accompanying drawing.