Conformable Microporous Fiber and Woven Fabrics Containing Same

Abstract

Expanded polytetrafluoroethylene (ePTFE) monofilament fibers and woven fabrics formed from the ePTFE fillers are provided, The ePTFE fibers have a substantially rectangular configuration, a density less than about 1.0 glee, and an aspect ratio greater than 15. Additionally, the ePTFE fibers are microporous and have a node and fibril structure. The ePTFE fiber may be woven into a fabric without first twisting the fiber. A polymer membrane and/or a textile may be laminated to the woven fabric to produce a laminated article. The ePTFE woven fabric simultaneously possesses high moisture vapor transmission (highly breathable) and high water entry pressure (water resistant). The woven fabric is quiet, soft, and drapable, making it especially suitable for use in garments, gloves and footwear applications. Treatments may be provided to the surface of the ePTFE fiber and/or the woven fabric to impart one or more desired functionality, such as, for example, oleophobicity).

What is claimed is: 
     
         1 . A woven fabric comprising:
 a plurality of warp fibers and weft fibers, each said warp fibers and each said weft fibers comprising expanded polytetrafluoroethylene (ePTFE) fibers having a substantially rectangular cross sectional configuration,   wherein a pre-woven width of said ePTFE fiber is greater than a width allotted to said ePTFE fiber based on an end count or pick count of said woven fabric.   
     
     
         2 . The woven fabric of  claim 1 , wherein said ePTFE fibers are monofilament fibers, 
     
     
         3 . The woven fabric of  claim 1 , wherein said ePTFE fibers have a density less than about 1.2 g/cm 3 . 
     
     
         4 . The woven fabric of  claim 1 , wherein said ePTFE fibers have a pre weaving density less than about 0.85 g/cm 3 . 
     
     
         5 . The woven fabric of  claim 1 , wherein said ePTFE fibers have nodes and fibrils defining passageways through said fiber, and
 wherein said fibrils have a length from about 5 microns to about 120 microns.   
     
     
         6 . The woven fabric of  claim 1 , wherein said woven fabric has an air permeability less than about 5 cfm. 
     
     
         7 . The woven fabric of  claim 5 , wherein said woven fabric has a moisture vapor transmission rate greater than about 10,000 g/m 2 /24 hours. 
     
     
         8 . The woven fabric of  claim 1 , wherein said woven fabric has a water pick-up less than about 30 gsm. 
     
     
         9 . The woven fabric of  claim 1 , wherein said ePTFE. fibers have an aspect ratio greater than about 15. 
     
     
         10 . The woven fabric of  claim 1 , wherein said ePTFE fibers have a weight per length of less than about 500 dtex. 
     
     
         11 . The woven fabric of  claim 1 , wherein said woven fabric has an average stiffness of less than about 300 g. 
     
     
         12 . The woven fabric of  claim 1 , wherein said woven fabric has a weight per unit area of less than about 300 g/m 2 . 
     
     
         13 . The woven fabric of  claim 1 . wherein said woven fabric has a tear strength of at least 30 N. 
     
     
         14 . The woven fabric of  claim 1 , wherein said woven fabric has an average water entry pressure greater than about 1 kPa. 
     
     
         15 . The woven fabric of  claim 1 , wherein said warp fibers and said weft fibers have a fluoroacrylate coating to render said woven fabric oleophobic. 
     
     
         16 . The woven fabric of  claim 15 , further comprising a functional membrane affixed to said warp and said weft fibers on a side opposing said fiuoroacrylate coating. 
     
     
         17 . The woven fabric of  claim 16 , further comprising a textile affixed to said functional membrane. 
     
     
         18 . The woven fabric of  claim 15 , further comprising a textile affixed to said warp fibers and weft fibers on a side opposing said fluoroacrylate coating. 
     
     
         19 . The woven fabric of  claim 1 , further comprising at least one of a textile and a functional membrane affixed to said woven fabric. 
     
     
         20 . The woven fabric of  claim 1 , wherein said woven fabric is in the form of a garment, a glove, or footwear. 
     
     
         21 . A woven fabric comprising:
 a plurality of warp fibers and weft fibers, each said warp fibers and said weft fibers comprising expanded polytetrafluoroethylene (ePTFE) fibers having a density less than about 1.2 g/cm 3  and a substantially rectangular cross sectional configuration.   
     
     
         22 . The woven fabric of  claim 21 , wherein said ePTFE fibers are monofilament fibers. 
     
     
         23 . The woven fabric of  claim 21 , wherein said woven fabric has a water entry pressure greater than about 1 kPa. 
     
     
         24 . The woven fabric of  claim 21 , wherein said woven fabric has a moisture vapor transmission rate greater than about 10,000 g/m 2 /24 hours. 
     
     
         25 . The woven fabric of  claim 21 , wherein said fabric has a water pick-up less than about 30 gsm. 
     
     
         26 . The woven fabric of  claim 21 , wherein said fabric has a weight per unit area less than about 300 g/m 2 . 
     
     
         27 . The woven fabric of  claim 21 , wherein at least one of said warp and well fibers has an aspect ratio greater than about 15. 
     
     
         28 . The woven fabric of  claim 21 , wherein said woven fabric has an air permeability less than about 5 cfm. 
     
     
         29 . The woven fabric of a  claim 21 , wherein each said warp and said weft fibers have a pre-weaving thickness of less than about 100 microns and a pre-weaving width of less than about 4.0 mm. 
     
     
         30 . The woven fabric of  claim 29 , wherein said width of said warp and said weft fibers is greater than a width allotted to said expanded polytetrafluoroethylene fibers based on an end count or a pick count of said woven fabric. 
     
     
         31 . The woven fabric of  claim 21 , wherein said expanded polytetrafluoroethylene fibers have a pre-weaving density less than about 0.85 g/cm 3 . 
     
     
         32 . The woven fabric of  claim 21 , wherein said woven fabric has an average stiffness of less than about 300 g. 
     
     
         33 . The woven fabric of  claim 21 , wherein said woven fabric has a tear strength of at least 30 N. 
     
     
         34 . The woven fabric of  claim 21 . Wherein said warp fibers and said weft fibers have a fluoroacrylate coating to render said woven fabric oleophobic. 
     
     
         35 . The woven fabric of  claim 34 , further comprising a functional membrane affixed to said warp fibers and said weft fibers on a side opposing said fluoroacrylate coating. 
     
     
         36 . The woven fabric of  claim 35 . further comprising a textile affixed to said functional membrane. 
     
     
         37 . The woven fabric of  claim 34 , further comprising a textile affixed to said warp fibers and well fibers on a side opposing said fluoroacrylate coating. 
     
     
         38 . The woven fabric of  claim 21 , further comprising at least one of a textile and a functional membrane affixed to said woven fabric. 
     
     
         39 . The woven fabric  claim 21 , wherein said ePTFE fibers have a node and fibril structure defining passageways through said fibers, said fibrils having a length from about 5 microns to about 120 microns. 
     
     
         40 . The woven fabric  claim 21 , wherein said woven fabric is in the form of a garment, a glove, or footwear. 
     
     
         41 . A woven fabric comprising:
 warp and weft fibers comprising expanded polytetrafluoroethylene (ePTFE) fibers having a substantially rectangular cross-section configuration,   wherein said woven fabric has a water entry pressure greater than about 1 kPa, and   wherein said woven fabric has a moisture vapor transmission rate greater than about 10,000 g/m 2 124 hours.   
     
     
         42 . The woven fabric of  claim 41 , wherein said ePTFE fibers are monofilament fibers. 
     
     
         43 . The woven fabric of  claim 41 , wherein a pre-weaving density of said expanded polytetrafluoroethylene fibers is less than about 0.85 g/cm 3 . 
     
     
         44 . The woven fabric of  claim 41 , wherein said warp and weft fibers have a pre-weaving thickness less than about 100 microns and a pre-weaving width less than about 4.0 mm. 
     
     
         45 . The woven fabric of  claim 44 , wherein said width of said expanded polytetrafluoroethylene fibers is greater than a width allotted to said expanded polytetrafluoroethylene fibers in said woven fabric based on an end count or pick count of said woven fabric. 
     
     
         46 . The woven fabric of  claim 41 , wherein said expanded polytetrafluoroethylene fibers are conformable such that in a woven configuration, said expanded polytetrafluoroethylene fiber folds upon itself. 
     
     
         47 . The woven fabric of  claim 41 , wherein said woven fabric has an average stiffness less than about 300 g. 
     
     
         48 . The woven fabric of  claim 41 , wherein said woven fabric has an air permeability less than about 5 cfm. 
     
     
         49 . The woven fabric of  claim 41 , wherein said woven fabric has a tear strength of at least 30 N. 50, The woven fabric of  claim 41 , wherein said woven fabric has an average water entry pressure greater than about 2 kPa. 
     
     
         51 . The woven fabric of  claim 41 , wherein said fabric has a weight per unit area less than about 300 g/m 2 . 
     
     
         52 . The woven fabric of  claim 41 , wherein said warp fibers and said weft fibers have a fluoroacrylate coating. 
     
     
         53 . The woven fabric of  claim 52 , further comprising a functional membrane affixed to said warp fibers and said weft fibers on a side opposing said fluoroacrylate coating. 
     
     
         54 . The woven fabric of  claim 53 , further comprising a textile affixed to said functional membrane. 
     
     
         55 . The woven fabric of  claim 52 , further comprising a textile affixed to said warp fibers and said weft fibers on a side opposing said fluoroacrylate coating. 
     
     
         56 . The woven fabric of  claim 41 , further comprising at least one of a textile and a functional membrane affixed to said woven fabric. 
     
     
         57 . The woven fabric of  claim 41  wherein said expanded polytetrafluoroethylene (ePTFE) fibers have a node and fibril structure defining passageways through said fibers, said fibrils having a length from about 5 microns to about 120 microns. 
     
     
         58 . The woven fabric of  claim 57 , wherein said ePTFE fibers are monofilament fibers. 
     
     
         59 . The woven fabric of  claim 41 , wherein said woven fabric is in the form of a garment, a glove, or footwear. 
     
     
         60 . A woven fabric comprising:
 warp and weft fluoropolymer fibers having a length and a width, at least one of said warp and said weft fluoropolymer fibers being in a folded configuration along said length of said fiber.   
     
     
         61 . The woven fabric of  claim 60 , wherein said woven fabric has a moisture vapor transmission rate greater than about 10,000 g/m 2 /24 hours and a water entry pressure greater than about 1 kPa. 
     
     
         62 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers have a weight per length of less than about 500 dtex. 
     
     
         63 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers have an aspect ratio greater than about 15. 
     
     
         64 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers are conformable such that in a woven configuration, said fluoropolymer fibers fold upon themselves. 
     
     
         65 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers are monofilament fibers having a porous microstructure. 
     
     
         66 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers have nodes and fibrils defining passageways through said fiber, and
 wherein said fibrils have a length from about 5 microns to about 120 microns.   
     
     
         67 . The woven fabric of  claim 60 , wherein said fluoropolymer fibers are expanded polytetrafluoroethylene (ePTFE) fibers. 
     
     
         68 . The woven fabric of  claim 67 , wherein said ePTFE fibers have a density less than about 1.2 g/cm 3 . 
     
     
         69 . The woven fabric of  claim 67 , wherein said ePTFE fibers are monofilament fibers. 
     
     
         70 . The woven fabric of  claim 67 , wherein said ePTFE fibers have a pre-weaving density less than about 0.85 g/cm 3 . 
     
     
         71 . The woven fabric of  claim 67 , wherein said width of said ePTFE fibers is greater than a width allotted to said ePTFE fibers in said woven fabric based on an end count or a pick count of said woven fabric. 
     
     
         72 . The woven fabric of  claim 67 , wherein said ePTFE fibers have a pre-weaving width less than about 4.0 mm and a pre-weaving thickness less than about 100 microns. 
     
     
         73 . The woven fabric of  claim 67 , wherein said woven fabric has a water pick-up less than about 30 gsm. 
     
     
         74 . The woven fabric of  claim 67 , wherein said ePTFE fibers have an aspect ratio greater than about 15. 
     
     
         75 . The woven fabric of  claim 67 , wherein said woven fabric has an average stiffness of less than about 300 g. 
     
     
         76 . The woven fabric of  claim 67 , wherein said woven fabric has an air permeability less than about 5 cfm. 
     
     
         77 . The woven fabric of  claim 67 , wherein said woven fabric has a weight per unit area of less than about 300 g/m 2 . 
     
     
         78 . The woven fabric of  claim 67 , wherein said warp fibers and said weft fibers have a fluoroacrylate coating. 
     
     
         79 . The woven fabric of  claim 78 , further comprising a functional membrane affixed to said warp fibers and said well fibers on a side opposing said fluoroacrylate coating. 
     
     
         80 . The woven fabric of  claim 79 , further comprising a textile affixed to said functional membrane. 
     
     
         81 . The woven fabric of  claim 78 , further comprising a textile affixed to said warp fibers and said well fibers on a side opposing said fluoroacrylate coating. 
     
     
         82 . The woven fabric of  claim 67 , further comprising at least one of a textile and a functional membrane affixed to said woven fabric. 
     
     
         83 . The woven fabric of  claim 67 , wherein said ePTFE fibers have a break strength of at least about 1.5 N. 
     
     
         84 . The woven fabric of  claim 67 , wherein said fabric is in the form of a garment, a glove, or footwear. 
     
     
         85 . A woven fabric comprising warp and weft fluoropolymer fibers having a node and fibril structure defining passageways through said fiber, said fluoropolynier fibers being microporous,
 wherein said woven fabric has an air permeability less than about 5 cfm and a moisture vapor transmission rate greater than about 10,000 g/m 2 /24 hours.   
     
     
         86 . The woven fabric of  claim 85 , wherein said fluoropolymer fibers are expanded polytetrafluoroethylene fibers. 
     
     
         87 . The woven fabric of  claim 87 , wherein said expanded polytetrafluoroethylene fibers have a pre-weaving density of less than about 0.85 g/cc. 
     
     
         88 . The woven fabric of  claim 85 , wherein said woven fabric has a water entry pressure greater than about 1 kPa. 
     
     
         89 . The woven fabric of  claim 85 , wherein said fabric has a water pick-up less than about 30 gsm. 
     
     
         90 . The woven fabric of  claim 85 , wherein said fabric has a weight per unit area of 300 g/m 2 . 
     
     
         91 . The woven fabric of  claim 85 , wherein at least one of said warp and weft fluoropolymer fibers has an aspect ratio greater than about 15. 
     
     
         92 . The woven fabric of a  claim 85 , wherein each said warp and said weft fluoropolymer fibers have a pre-weaving thickness less than about 100 microns and a width less than about 4.0 mm. 
     
     
         93 . The woven fabric of  claim 85 , wherein said width is greater than a width allotted to the fluoropolymer fiber based on an end count or a pick count of said woven fabric. 
     
     
         94 . The woven fabric of  claim 85 , wherein said woven fabric has an average stiffness of less than about 300 g. 
     
     
         95 . The woven fabric of  claim 85 , wherein said woven fabric has a tear strength of at least 30 N. 
     
     
         96 . The woven fabric of  claim 85 , wherein said fibrils have length from about 5 microns to about 120 microns. 
     
     
         97 . The woven fabric of  claim 85 , further comprising at least one of a textile and a fluoropolymer membrane affixed to said woven fabric. 
     
     
         98 . The woven fabric of  claim 85 , wherein said woven fabric is in the form of a garment, a glove, or footwear.