Process for producing motor vehicle seat cushioning

Abstract

The invention relates to a method for creating a motor vehicle seat cushion, the said method providing a cover comprising a format (2) of a complex comprising a layer of covering material (3) and a sublayer of elastically compressible foam (4), and arranging on the said sublayer a film (8) based on thermoplastic polyurethane, the said film having a melting point and a melt mass-flow index such that it breaks down under the action of the heat released during the formation of the foam, the said film being provided with a reinforcing thin-film (11) so as to form a two-layer barrier against the penetration of foam, the said reinforcing thin-film being based on a thermoplastic polyurethane with a melting point higher than that of the said film and having a melt mass-flow index lower than that of the said film, so as to have greater strength than the said film so that its breakdown under the action of heat is delayed.

Description

technical field [0001] The invention relates to a method of manufacturing a seat pad for a motor vehicle, a seat pad manufactured according to such a manufacturing method, and a motor vehicle seat with such a seat pad. Background technique [0002] It is known, in particular according to document WO-2018 / 020149-A1, to carry out a production method of a seat pad for a motor vehicle, said production method comprising the following steps: [0003] - providing a cover comprising a forming part of the composite body comprising a layer of coating material and a bottom layer made of elastically compressible foam, [0004] placing said forming member in a mold defining a mold cavity, said layer of coating material being disposed against a wall of the mold cavity, [0005] arranging a thermoplastic polyurethane based film on said bottom layer, [0006] A precursor mixture of an elastically compressible foam is injected into the mold cavity to form a filled block, the film having a ...

AI Technical Summary

Problems solved by technology

[0013] In some cases, however, the membranes advocated for use have proven to be insufficiently strong

[0014] This is especially the case when the hood has a complex geometry, which deforms the membrane severely, which risks premature degradation of said membrane, especially by locally drilling holes, which can lead to When overmolding the base layer, this may allow the foam to seep into the base layer too much

[0015] The same is true when the upholstery has to have high load-bearing properties - such as in the case of seat upholstery - which requires intensive filling of the mold with the foam precursor mixture, which leads to a high pressure in the mold cavity which in turn can lead to the aforementioned film Premature degradation occurs

[0016] In this case, it can be observed that the membrane degrades too quickly, which prevents the pressure rise of the foam in the mold at the end of the rise time, and risks causing the surface of said foam to exhibit pitted (or collapsed) defects, leading to the failure of the liner. Deterioration of comfort and / or appearance attributes

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