Mat made of waterproof plastic material for the sub-base of synthetic turfs or pavings and the like

Abstract

The mat further includes one or more coupling elements for mutual interconnection with other mats so as to compose a single turf for the complete covering of a predetermined bed surface. Thehe lower face and the upper face include a plurality of ribs adapted to absorb and return mechanical stresses. The ribs include longitudinal lines which form channels for the horizontal draining of the water on the upper face.

1 . A mat made of waterproof plastic material for the sub-base of synthetic turfs or pavings, adapted to be arranged between a bed surface and a covering layer, the mat comprising:
 a membrane having a lower face adapted to be rested on said bed surface and an upper face adapted to be covered by said covering layer; and   one or more coupling elements for mutual interconnection with other mats so as to compose a single mat for the complete covering of a predetermined bed surface;   said lower face and said upper face comprising a plurality of ribs adapted to absorb and return mechanical stresses;   wherein said ribs comprise longitudinal lines which form channels for the horizontal draining of the water on said upper face.   
     
     
         2 . The mat according to  claim 1 , wherein on said upper face said ribs also comprise transverse lines which are lower than said longitudinal lines and are adapted to create accumulations of water. 
     
     
         3 . The mat according to  claim 1 , wherein one or more cuts for the passage of water between at least two of said channels are provided on said longitudinal lines. 
     
     
         4 . The mat according to  claim 1 , wherein said ribs form a plurality of receptacles on said lower face. 
     
     
         5 . The mat according to  claim 4 , wherein said transverse lines have a spacing that is equal to the spacing of said receptacles. 
     
     
         6 . The mat according to  claim 1 , wherein the mat is divided into at least two longitudinal portions mutually connected by means of an expansion joint adapted to compensate for the thermal expansions and contractions by deforming. 
     
     
         7 . The mat according to  claim 1 , further comprising one or more holes for the passage of water through said membrane. 
     
     
         8 . The mat according to  claim 1 , wherein said waterproof plastic material is constituted by a mixture composed of 15-25% thermoplastic polymer and 75-85% rubber, said rubber being obtained from used tires. 
     
     
         9 . The mat according to  claim 1 , further comprising a filter interposed between said upper face and said covering layer, said filter comprising material of the nonwoven fabric type. 
     
     
         10 . A playing field comprising a bed surface and a covering layer, said covering layer comprising at least one layer of synthetic grass, further comprising, between said covering layer and said bed surface, a plurality of mats according to  claim 1 . 
     
     
         11 . A method for providing a mat made of waterproof plastic material for the sub-base of synthetic turfs or pavings, the method including the following steps:
 providing a waterproofing mixture having thermoplastic material;   making said mixture exit in the plastic state from an extruder; and   calendering said mixture, making said mixture pass between two cooled contoured rollers, so that said rollers create a pressure on said mixture, giving said mixture the shape of a mat, and at the same time cool said mixture.   
     
     
         12 . The method according to  claim 11 , wherein said rollers are contoured so as to impart to said mixture the shape of a mat having a membrane including a lower face adapted to be rested on a bed surface and an upper face adapted to be covered by a covering layer, one or more coupling elements for mutual interconnection with other mats so as to compose a single mat for the complete covering of a predetermined bed surface, said lower face and said upper face comprising a plurality of ribs adapted to absorb and return mechanical stresses, wherein said ribs include longitudinal lines which form channels for the horizontal draining of the water on said upper face, and wherein said rollers are cooled to a temperature comprised between 5° C. and 8° C., cooling said mixture.