CHEMICAL BARRIER FABRIC
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.