Abstract: Structure of semifinished product (10) for floating products comprising a plurality of layers (1a-Id) of flexible material having density less than water, for example foam polyethylene, mutually constrained to each other. In particular, the layers (1a-Id) are arranged according to an overlapped configuration and then constrained at fastening points, for example, seams (6) made by a stitching head (50) equipped with one or more needles (55) acting along a direction (60) substantially orthogonal to the layers (1a-Id). Each seam point (6) is, in particular, insulated, i.e. is made in order to result distanced from the other seams (6). This is to avoid the production of weakening lines, or zones, in the semifinished product (10) and to obtain, then a highly flexible product and at the same time having a high mechanical resistance. The seams (6) can be made in a random way or following a predetermined scheme to provide a homogeneous distribution on all the surface of the layers (1a-Id).

Abstract: The base material can be obtained by means of the realisation, on a support made out of material or nonmaterial, of a system of two crossed orders, uniformly distributed, of rectilinear stitching carried out with a yarn having a metallic core inside. In this way, an incorporated shielding metallic screen made of metallic cores is obtained.

Abstract: A semi-finished composite material for the manufacture of buoyancy products and related products. The semi-finished composite material includes a plurality of layer of elastic and flexible waterproof material with a specific gravity substantially less than that of water, fastening means adaptable for associating the layers to each other so as to form a plurality of air filled spaces by consecutive ones of the fastening means between adjacent layers, wherein the fastening means of a plurality of quiltings spaced from each other so as to form the air filled spaces with the plurality of layers including the air spaces adapted to being further insertable between a lining and a coating.