Superficial fibrous formation of three-dimensional structure,method of obtaining same and application thereof

A fibrous structure has alternate raised and recessed portions and consists of non-woven pile layers (1, 2,) welded to shrunk surface structures (7), e.g. non-wovens, fabrics, nets, films. The welds (5) run perpendicular to the direction of greatest shrinkage and are in a pattern of regularly arranged lines. The pattern can be continuous or discontinuous, e.g. in regular hexagons. An Independent claim is also included for the process of laying down the pile layers and surface layers and joining them by welding in a linear pattern by heat and calender pressure or ultrasonically. The assembly is then heated to shrink the surface layers and form a structure with alternating recesses. Specifically claimed is the application in liquid or dust filtration, nappies or sanitary towels, hook component in hook and loop fasteners.