Structurally stable flame-retardant nonwoven fabric

Abstract

The present invention is directed to a hydroentangled flame-retardant nonwoven fabric, and more specifically, to a structurally stable flame-retardant fabric comprising at least two layers, wherein the fibrous components of the fabric have a synergistic relationship so as to maintain the integrity of the flame-retardant fabric upon burning. In accordance with the present invention, the nonwoven fabric is comprised of at least a first and second layer. The first layer comprises a blend of lyocell fiber and modacrylic fiber.

What is claimed is:  
     
         1 . A method of making a structurally stable hydroentangled flame-retardant nonwoven fabric comprising the steps of: 
 a. providing a first layer precursor web comprising a blend of lyocell fiber and modacrylic fiber;    b. providing a second precursor web comprising a blend of lyocell fiber, modacrylic fiber, and para-amid fiber;    c. positioning said first precursor web atop said second precursor web; and    d. hydroentangling said first and second precursor webs so as to form said nonwoven fabric.    
     
     
         2 . A method of making a structurally stable hydroentangled flame-retardant nonwoven fabric as in  claim 1 , wherein said first layer comprises a blend of 60% lyocell fiber and 40% modacrylic fiber.  
     
     
         3 . A method of making a structurally stable hydroentangled flame-retardant nonwoven fabric as in  claim 1 , wherein said second layer comprises a blend of 42% lyocell fiber, 37% modacrylic fiber, and 21% para-amid fiber.  
     
     
         4 . A method of making a structurally stable three-dimensionally imaged flame-retardant nonwoven fabric comprising the steps of: 
 a. providing a first layer precursor web comprising a blend of lyocell fiber and modacrylic fiber;    b. providing a second precursor web comprising a blend of lyocell fiber, modacrylic fiber, and para-amid fiber;    c. providing a three-dimensional image transfer device;    d. positioning said first precursor web atop said second precursor web;    e. advancing said first and second precursor webs onto said three-dimensional image transfer device; and    f. hydroentangling said first and second precursor webs so as to form said imaged nonwoven fabric.    
     
     
         5 . A structurally stable hydroentangled flame-retardant nonwoven fabric comprising a first layer and a second layer, wherein said first layer comprises a blend of lyocell fiber and modacrylic fiber and said second layer comprises a blend or lyocell fiber, modacrylic fiber, and para-amid fiber, whereby said first and second layers are hydroentangled so as to form said fabric.  
     
     
         6 . A structurally stable three-dimensionally imaged flame-retardant nonwoven fabric comprising a first layer and a second layer, wherein said first layer comprises a blend of lyocell fiber and modacrylic fiber and said second layer comprises a blend or lyocell fiber, modacrylic fiber, and para-amid fiber, whereby said first and second layers are hydroentangled on a three-dimensional image transfer device so as to form said fabric.