Sound insulating material

DETAILED DESCRIPTION OF THE INVENTION The following drawings serve to further illustrate the invention and shows: FIG.
1 a plan view of a foam layer with a zonally differing covering with an impregnating material foil prior to the impregnation; FIG.
2 a section through a portion of a sound insulating material according to the invention.
In the areas 1 the foam layer of FIG.
1 is free from damping composition.
A single layer of a damping composition foil is applied to areas 2, 2' and 2".
Damping is increased in areas 3, 3' by using a double layer, corresponding to a double quantity of damping composition.
Finally in area 4 a triple layer of the damping composition foil is applied, corresponding to extremely high damping.
The individual foils are melted by heating and consequently penetrate the foam, so that following cooling the latter can be used as a sound insulating material.
FIG.
2 shows a section through a material according to the invention.
In area 12 the foam layer is for example impregnated with 1.
2 kg/m.
sup.
2 and in area 13 with 2.
0 kg/m.
sup.
2 of damping compositions, so that in these areas the insulating material has a correspondingly high damping and in the non-impregnated areas exhibits optimum sound insulation.