Drained Barrier

Abstract

The invention provides a material for use in waterproofing or containment of liquids, gases or solids, the material comprising a layer which comprises an impermeable or a semi permeable barrier and is adapted to facilitate drainage, wherein the material comprises a geomembrane or waterproofing barrier material comprising a plurality of voids which facilitates drainage, said plurality of voids being provided by means of a layer which comprises a cuspated layer, said cuspated layer comprising a plurality of cusps, wherein said cusps are adapted so as to facilitate the joining of the edges or cuspated parts of said material to the cuspated parts of said material at any angle, said cusps having a shape and being located in a position on said material so as to facilitate said joining. The invention also provides a method for the formation of a barrier material from a plurality of samples of material according to the first aspect of the invention. The material and method according to the invention find particular application in the sealing of landfill sites.

1 . A material for use in waterproofing or containment of liquids, gases or solids, said material comprising a layer which comprises an impermeable or a semi permeable barrier and is adapted to facilitate drainage, wherein said material comprises a geomembrane or waterproofing barrier material comprising a plurality of voids which facilitates drainage, said plurality of voids being provided by means of a layer which comprises a cuspated layer, said cuspated layer comprising a plurality of cusps, wherein said cusps are adapted so as to facilitate the joining of the edges or cuspated parts of said material to the cuspated parts of said material at any angle, said cusps having a shape and being located in a position on said material so as to facilitate said joining.  
   
   
       2 . The material of  claim 1  wherein said cusps are cylindrical, frustoconical, truncated tetrahedral or any hollow shape.  
   
   
       3 . The material of  claim 1  wherein said cusps are arranged to project as protrusions on one side of the plane of the said layer.  
   
   
       4 . The material of  claim 1  wherein said cusps are arranged such that indentations and protrusions are observed on both sides of the said layer.  
   
   
       5 . The material of  claim 1  wherein said cusps protrude from the surface of said layer to a distance of between 1 mm and 15 mm.  
   
   
       6 . The material of  claim 1  wherein the cuspated layer is formed with flat areas along its edges, wherein said flat areas do not comprise cusps.  
   
   
       7 . The material of  claim 1  wherein the cuspated layer comprises cusps to the edges of the layer.  
   
   
       8 . The material of  claim 1  wherein the flat edges or cuspated parts of a sample of said material are joined to the cuspated parts of the same sample of said material.  
   
   
       9 . The material of  claim 1  wherein the flat edges or cuspated parts of one sample of said material are joined to the cuspated parts of at least one other sample of said material.  
   
   
       10 . The material of  claim 1  which comprises cusps and additional features adapted so as to facilitate the joining of the edges or cuspated parts of said material to the cuspated parts of said material at any angle, said cusps and additional features having a shape and being located in a position on said material so as to facilitate said joining.  
   
   
       11 . The material of  claim 10  wherein said additional features comprise small ridges, grooves or projections.  
   
   
       12 . The material of  claim 1  which comprises a plastics material.  
   
   
       13 . The material of  claim 12  which comprises a thermoplastic or thermoset plastics material.  
   
   
       14 . The material of  claim 12  which comprises a polyolefin.  
   
   
       15 . The material of  claim 14  which comprises polyethylene or polypropylene.  
   
   
       16 . The material of  claim 1  wherein the weight of said cuspated layer is in the range of from 300 to 3000 g/m 2  of material.  
   
   
       17 . The material of  claim 1  wherein said material additionally comprises at least one geotextile.  
   
   
       18 . The material of  claim 17  wherein said geotextile is releasably attached to said material.  
   
   
       19 . The material of  claim 18  wherein said releasable attachment is achieved by means of an adhesive.  
   
   
       20 . The material of  claim 19  wherein said adhesive comprises hot melts of EVA, rubber or polyolefins.  
   
   
       21 . The material of  claim 18  wherein said releasable attachment is achieved by means of flame bonding, techniques, by the insertion of pins, pegs or staples at various locations across the surface of the said layer, or by the incorporation of projections from the top of some or all of the cusps in a cuspated material, said projections being adapted to engage the said geotextile.  
   
   
       22 . A method for the formation of a barrier material, said method comprising: 
 (a) providing a plurality of samples of material according to any one of  claims 1  to  21 ;    (b) arranging said samples adjacent each other in a predetermined formation such that said materials are in contact with each other in certain locations; and    (c) forming said samples into a single barrier material by the formation of joins at said locations.    
   
   
       23 . The method of  claim 22  wherein the formation of joins at the stated locations is carried out by means of welding, extrusion, heating, application of tape or adhesive, or ultrasonics.  
   
   
       24 . The method of  claim 22  wherein said joins are formed by the action of a hot air/wedge welding machine.  
   
   
       25 . The method of  claim 24  wherein said joins comprises welds which are formed with cuspations, grooves or ridges such that the drainage is maintained across and/or along the join.  
   
   
       26 . The method of  claim 23  wherein the welded area is formed into cuspated, grooved or ridged profile by at least one shaped pressure roller or foot whilst the material in the weld is deformable.  
   
   
       27 . The method of  claim 26  which utilises a hot air wedge welding machine with at least one roller shaped to form a cuspated profile or ridges or grooves.  
   
   
       28 . The method of  claim 26  wherein said at least one roller provides the driving force to propel the welding machine.  
   
   
       29 . The method of  claim 23  which utilises a welding machine which comprises a set of rollers shaped to form the cuspated profile, ridges or grooves and a separate set of driving rollers to propel the welding machine.  
   
   
       30 . The method of  claim 22  which utilises a welding machine adapted so as to automatically separate a geotextile that is releasably attached to the material, maintain said geotextile in a location clear of the welding zone, and additionally re-attach said geotextile to the material after the welding process has been completed.  
   
   
       31 . The method of  claim 22  which comprises arranging one or more pieces of the said material to overlap each other in a uniform manner.  
   
   
       32 . The method of  claim 31  wherein said overlap is 20-600 mm.  
   
   
       33 . The method of  claim 32  wherein said overlap is 30-200 mm.  
   
   
       34 . The method of  claim 31  wherein the welding machine applies heat and pressure whilst gripping the samples of material and either being propelled, or propelling itself.  
   
   
       35 . The method of  claim 22  wherein a third sample of material is introduced alongside first and second samples of said material such that there exists an overlap onto each sample of said material.  
   
   
       36 . The method of  claim 35  wherein said overlap is 20-600 mm.  
   
   
       37 . The method of  claim 36  wherein said overlap is 30-200 mm.  
   
   
       38 . The method of  claim 35  wherein the welding machine applies heat and pressure to both sides of said material whilst gripping all three samples of material and either being propelled, or propelling itself, along.  
   
   
       39 . The method of  claim 22  wherein said joins are formed by means of a twin weld comprising a test channel by means of which the integrity of the joins can be determined.  
   
   
       40 . A barrier material prepared by the method of any one of  claims 22  to  39 .  
   
   
       41 . The barrier material of  claim 40  whenever applied to the sealing of landfill sites.  
   
   
       42 . The material of any one of  claims 1  to  21  whenever applied to the sealing of landfill sites.  
   
   
       43 . The method of any one of  claims 22  to  39  whenever applied to the sealing of landfill sites.