Multilayer net for draining fluids, particularly for geotechnical use

Abstract

A multilayer net for draining fluids, particularly for geotechnical use, comprising an intermediate layer, constituted by a plurality of intermediate and substantially mutually parallel filaments, and first and second outer layers, which are constituted by first and second outer filaments which are inclined with respect to the intermediate filaments, the intermediate filaments forming an angle other than zero with respect to the main direction of extrusion of the net from an extruder.

What is claimed is: 
     
         1 . A multilayer net for draining fluids, particularly for geotechnical use, comprising an intermediate layer, constituted by a plurality of intermediate and substantially mutually parallel filaments, and first and second outer layers, which are constituted by first and second outer filaments which are inclined with respect to said intermediate filaments, wherein said intermediate filaments form an angle other than zero with respect to the main direction of extrusion of said net from an extruder. 
     
     
         2 . The multilayer net according to  claim 1 , wherein said intermediate filaments form an angle from 20 to 90° with respect to the main extrusion direction. 
     
     
         3 . The multilayer net according to  claim 1 , wherein said first and second external filaments are mutually inclined. 
     
     
         4 . The multilayer net according to  claim 1 , wherein said first and second external filaments are mutually parallel and said intermediate filaments lie substantially at 90° with respect to the direction of extrusion from the extruder. 
     
     
         5 . The multilayer net according to  claim 1 , comprising a first external covering layer and a second external covering layer, which are associated respectively with said first and second external filaments. 
     
     
         6 . Use of a multilayer net according to  claim 1 , wherein said net can be arranged longitudinally with respect to an extension of a road on which transverse drainage is to be provided.