Chemical barrier fabric

Abstract

A chemical barrier fabric ( 12 ) and a method of manufacturing the fabric is described. The chemical barrier fabric ( 12 ) includes at least first ( 18 ) and second ( 20 ) chemical barrier layers which have an interfacial region therebetween and which are intermittently point bonded ( 34 ) providing a point-bonded area which is in the minority and an un-bonded area ( 36 ) which is in the majority in the interfacial region. The chemical barrier layers ( 18, 20 ) typically comprise single layer polymer films and/or co-extruded layers. A non-woven layer 22 may also be point-bonded to either the first ( 18 ) or the second ( 20 ) chemical barrier layer to give support to the fabric ( 12 ).

1 . A laminated chemical barrier fabric including at least first and second chemical barrier layers, which have an interfacial region therebetween and which are intermittently point bonded providing a point-bonded area which is in the minority and an un-bonded area which is in the majority in the interfacial region. 
     
     
         2 . A laminated chemical barrier fabric according to  claim 1 , wherein the majority un-bonded area is at least about 60% and the minority point-bonded area is no more than about 40% of a planar face of a chemical barrier layer in the interfacial region. 
     
     
         3 . A laminated chemical barrier fabric according to  claim 1 , wherein the minority point-bonded area is from approximately 1% to approximately 40% of a planar face of a chemical barrier layer in the interfacial region between the chemical barrier layers. 
     
     
         4 . A laminated chemical barrier fabric according to  claim 1 , wherein the minority point bonded area is from approximately 2% to approximately 19% of a planar face of a chemical barrier layer in the interfacial region between the chemical barrier layers. 
     
     
         5 . A laminated chemical barrier fabric according to  claim 1 , wherein the minority point-bonded area is from approximately 19% to approximately 40% of a planar face of a chemical barrier layer in the interfacial region between the chemical barrier layers. 
     
     
         6 . A laminated chemical barrier fabric according to  claim 1 , wherein the point-bond area comprises from approximately 1% to approximately 40% or from approximately 2% to approximately 19%, or from approximately 19% to approximately 40%, or is approximately 19%, or is no more than about 40% of a surface of the fabric. 
     
     
         7 . A laminated chemical barrier fabric according to  claim 1 , wherein the first and second chemical barrier layers includes a single layer polymer film. 
     
     
         8 . A laminated chemical barrier fabric according  claim 1 , wherein the first chemical barrier layer comprises a single layer polymer film, and the second chemical barrier layer comprises a co-extruded polymer film. 
     
     
         9 . A laminated chemical barrier fabric according to  claim 1 , wherein the first and second chemical barrier layers each includes a co-extruded polymer film. 
     
     
         10 . A laminated chemical barrier fabric according to  claim 7 , wherein the single layer polymer film is of a polyolefin. 
     
     
         11 . A laminated chemical barrier fabric according to  claim 10 , wherein the polyolefin is polypropylene and/or a polypropylene copolymer. 
     
     
         12 . A laminated chemical barrier fabric according to  claim 9 , wherein the co-extruded polymer film comprises a middle layer disposed between first and second polyolefin outer layers. 
     
     
         13 . A laminated chemical barrier fabric according to  claim 12 , wherein the middle layer is selected from the group comprising ethylene vinyl alcohol, polyvinylidine chloride resin and polyamide resin. 
     
     
         14 . A laminated chemical barrier fabric according to  claim 12 , wherein the first and second polyolefin outer layers comprise polypropylene and/or a polypropylene copolymer. 
     
     
         15 . A laminated chemical barrier fabric according to  claim 12 , wherein the layers of the co-extruded film are bonded by adhesive tie layers. 
     
     
         16 . A laminated chemical barrier fabric according to  claim 15 , wherein the adhesive tie layers are approximately 4 microns thick. 
     
     
         17 . A laminated chemical barrier fabric according to  claim 12 , wherein the middle layer of the co-extruded polymer film is approximately 4 microns thick. 
     
     
         18 . A laminated chemical barrier fabric according to  claim 12 , wherein the first and second outer layers of the co-extruded polymer film are approximately 8 to approximately 20 microns thick. 
     
     
         19 . A laminated chemical barrier fabric according to  claim 1 , further including a non-woven layer point-bonded to the first or second chemical barrier layer. 
     
     
         20 . A laminated chemical barrier fabric according to  claim 19 , wherein the non-woven layer includes a polyolefin. 
     
     
         21 . A laminated chemical barrier fabric according to  claim 19 , wherein the non-woven layer includes a spunbond polypropylene. 
     
     
         22 . A laminated chemical barrier fabric according to  claim 8 , wherein the composition of the polymer film is substantially identical to the composition of the first and second outer layers of the co-extruded film. 
     
     
         23 . A laminated chemical barrier fabric according to  claim 19 , wherein the composition of the non-woven layer is substantially identical to the composition of the polymer film, and/or to the first and second outer layers of the co-extruded film. 
     
     
         24 . A method of manufacturing a laminated chemical barrier fabric by a lamination process including intermittently point-bonding at least first and second chemical barrier layers which have an interfacial region therebetween to provide a point-bonded area which is in the minority and an un-bonded area which is in the majority in the interfacial region.