Abstract: A panel absorbing acoustical energy at low, medium and high frequencies, particularly at frequencies ranging from 400 Hz to 5,000 Hz, is essentially constituted by a plate (1) of semi-rigid foam with open communicating cells and by a layer (2) of bonded fibers or by a flexible cellular material. The assembly acts according to a mass-spring principle. The plate (1) of semi-rigid foam with open communicating cells constitutes the mass of the assembly functioning according to the mass-spring principle, while the layer (2) of bonded fibers or of flexible cellular material constitutes the spring of this assembly. The foam comprising the plate (1) is preferably a semi-rigid polyurethane foam of a density ranging from 20 kg/m.sup.3 to 50 Kg/m.sup.3, of a thickness comprised between 5 mm and 15 mm and whose permeability to air is comprised between 5 liters per minute and 45 liters per minute for a specimen 80 mm in diameter. The layer (2) constituting the spring has a stiffness ranging from 0.007 MPa to 0.

Abstract: Cushions are produced from padding of polyurethane foam cast in situ in a textile covering. There are disposed successively in a mold (1) a textile (2) overlaid by a foam sheet (3) with cells that are open and communicating, and then a fluid-tight film (4), e.g. of glue. The composite (5) thus obtained, adapted to constitute the covering of the cushion, is held against the internal wall (6) of the mold (1) by suction, and then there is cast in the mold (1) a foaming mixture of polyurethane (7) which expands and hardens after closing of the mold (1). Finally, a microperforation of the fluid-tight film (4) is effected, thereby to confer on it good permeability to water vapor and permitting also to generate, by the effect of suction, an underpressure in the foam (8) in the course of hardening, such that the resulting padding of foam (8) will have, after polymerization and demolding, constituent cells (11) that are open and communicating.

Abstract: A process for the production of a headrest with an articulated insert, comprises casting in situ polyurethane foam (7) within an external cover in which is disposed an insert (5) having articulated legs (4) that protrude from the cover, then hollowing out, by means of heating elements (2), swinging spaces (3) for the articulated legs (4) of the insert (5) by hot fusion of the external cover (6) and of the polyurethane foam (7) at the corresponding locations (8) of the headrest (1), and simultaneously heat sealing the external cover (6) and the surface of the polyurethane foam (7) bordering the swinging spaces (3).

Abstract: The disclosure is of a process for moulding cellular polycarbodiimide, characterized in that it consists essentially in heating a panel by radiation and direct contact in a mould-die assembly, in compressing this panel when the foam reaches its softening point, so as to increase its density, in deforming it and rendering the material less friable, more elastic, smooth, calendered and of higher mechanical quality, while retaining its inherent qualities of non-inflammability, and finally in slightly cooling the mould after the moulding, for example by means of an air jet, so as slightly to harden the moulded product before the die is withdrawn and the said product is withdrawn from the mould.

Abstract: The disclosure is of a moulded light-weight panel and its manufacture, the panel comprising sheets of foamed material and cardboard, which may be corrugated, impregnated with a solution of elastomer which becomes polymerized to bond all the components of the panel together in a mould. Reinforcing and fastening elements may be incorporated in the panel.

Abstract: The disclosure is of a moulded light-weight panel and its manufacture, the panel comprising sheets of foamed material and cardboard, which may be corrugated, impregnated with a solution of elastomer which becomes polymerized to bond all the components of the panel together in a mould. Reinforcing and fastening elements may be incorporated in the panel.