Nonwoven metal fabric and method of making same

Abstract

A nonwoven, metal fabric is formed by providing a mass of loose fibers with sufficient lubricating oil for them to be carded without disintegration of the fiber web. The fiber web is then lapped and needled to form a metal fabric of superior strength, density, and thermal insulation properties.

What is claimed is:  
     
         1 . A nonwoven metal fabric formed by 
 providing a mass of loose fibers with a lubricant;    separating fibers from the mass;    carding the separated fibers on a garnett to form a fiber web;    lapping the fiber web to form multiple layers of metal fibers; and    needling the multiple layers to interengage the fibers between the layers.    
     
     
         2 . The fabric of  claim 1 , wherein the mass of loose fibers is formed by shaving a metal member with a succession of serrated blades selected so that the fibers having irregular cross-sections and rough outer surfaces, the irregular cross-sections varying along the lengths of the fibers.  
     
     
         3 . The fabric of  claim 2 , wherein the fibers are selected from the group consisting of carbon steel, stainless steel, copper, and brass.  
     
     
         4 . The fabric of  claim 3 , wherein the fibers have average cross-sectional diameters of from about 25 to about 125 microns with lengths of the fibers ranging between about 1 to about 10 inches.  
     
     
         5 . The fabric of  claim 4 , consisting only of metal fibers.  
     
     
         6 . The fabric of  claim 4 , wherein the longitudinal variation of the cross-sections of the fibers forms barbs in the outer surfaces to enhance mutual interengagement of the fibers.  
     
     
         7 . The fabric of  claim 6 , wherein the lubricant comprises oil, and wherein the mass of loose fibers has sufficient oil on the outer surfaces of the fibers to inhibit substantial disintegration of the web when it is carded.  
     
     
         8 . The fabric of  claim 7 , wherein the metal fibers are selected from the group consisting of stainless steel, copper, and brass, and wherein the oil is applied to the metal fibers after they have been shaved from the metal member.  
     
     
         9 . The fabric of  claim 7 , wherein the metal fibers are carbon steel and the oil is applied to the metal member so that the metal fibers having a portion of the oil disposed on their outer surfaces after the fibers are shaved from the member.  
     
     
         10 . A nonwoven metal fabric comprising: 
 a mass of loose metal fibers, the fibers having irregular cross-sections and rough outer surfaces, the irregular cross-sections varying along the lengths of the fibers to form barbs in the outer surfaces to enhance interengagement of the fibers; and    a non-aqueous lubricant disposed on the outer surfaces of the fibers;    wherein the metal fabric is formed by 
 carding the fibers on a garnett to form a fiber web, the lubricant being disposed on the fibers in sufficient amount to inhibit substantial disintegration of the web when it is carded; lapping the fiber web while changing the orientation of the fiber web to form multiple layers of metal fibers, the orientation of adjacent layers being rotated out of alignment from each other by a preselected angle; and  
 needling the multiple layers to interengage the fibers of respective layers.  
   
     
     
         11 . A method of making a nonwoven metal fabric comprising the steps of: 
 providing a mass of loose fibers with a lubricant,    separating fibers from the mass;    carding the separated fibers on a garnett to form a fiber web;    lapping the fiber web to form multiple layers of said web; and    needling the multiple layers to interengage the fibers of respective layers to form the fabric.    
     
     
         12 . The method of  claim 11 , wherein the step of providing the mass of fibers with a lubricant comprises the step of providing a sufficient amount of oil to outer surfaces of the fibers to inhibit substantial disintegration of the web during the carding step.  
     
     
         13 . The method of  claim 12  further comprising the step of forming the metal fibers by shaving a metal member with a succession of serrated blades so that the fibers have irregular cross-sections and rough outer surfaces, the irregular cross-sections varying along the length of the fibers.  
     
     
         14 . The method of  claim 13 , wherein the metal fibers are selected from the group consisting of stainless steel, copper, and brass, and wherein the step of providing oil to the fibers further comprises applying the oil to the metal fibers after they have been shaved from the member.  
     
     
         15 . The method of  claim 13 , wherein the step of providing oil to the fibers comprises applying the oil to the metal member so that a portion of the oil applied to the metal member adheres to the fibers after the fibers are shaved from the member.