Cross-lapped multilayer fibrous batt and method of making the same

Abstract

A cross-lapped multilayered batt, and a method of making the same is presented. The batt includes one or more layers of a carded web of staple fibers, and one or more continuous filament fiber layers. At least some of the staple fibers and, in some instances, some of the continuous filament fibers are mechanically entangled through a thickness of the batt. The method includes folding both the carded web and the continuous filament fiber layers together, and subjecting the folded layers to a needle-punching process to impart structural stability and enhance the Z-directional strength of the batt.

What is claimed is: 
     
         1 . A cross-lapped multilayered batt comprising:
 one or more layers of a carded web of staple fibers; and   one or more continuous filament fiber layers comprising a plurality of continuous filament fibers, wherein
 each layer of the multilayered batt comprises the one or more layers of the carded web and the continuous filament fiber layers, and 
 the multilayered batt comprises an X direction along a width of the batt, a Y direction along a length of the multilayered batt, and a Z direction extending through a thickness of the multilayered batt, wherein at least some staple fibers of at least one layer of the carded web are mechanically entangled with at least some other staple fibers of another layer of carded web, such that the mechanically entangled staple fibers extend along the Z direction of the multilayered batt, thereby enhancing a Z-directional strength of the multilayered batt. 
   
     
     
         2 . The multilayered batt of  claim 1 , wherein at least some staple fibers of the at least one layer of the carded web are mechanically entangled with at least some continuous filament fibers, such that each of the mechanically entangled staple fibers and the mechanically entangled continuous filament fibers extend along the Z direction of the multilayered batt. 
     
     
         3 . The multilayered batt of  claim 1 , wherein the one or more layers of carded web comprises a first carded web and a second carded web in a layered, facing relationship with one another, and wherein the continuous filament fiber layer is disposed between the first carded web and the second carded web. 
     
     
         4 . The multilayered batt of  claim 1 , wherein the multilayered batt is dimensioned and molded to form and maintain a shape. 
     
     
         5 . The multilayered batt of  claim 4 , wherein the multilayered batt is molded to form a thermal-acoustical shield. 
     
     
         6 . The multilayered batt of  claim 1 , wherein the carded web comprises at least one of fiberglass, polyolefin, polyamide, aramid, cotton, flax and jute. 
     
     
         7 . The multilayered batt of  claim 1 , wherein the staple fibers are present in about up to 75% of a total mass of the batt. 
     
     
         8 . The multilayered batt of  claim 1 , wherein the staple fibers comprise at least one of random staple fibers and oriented staple fibers. 
     
     
         9 . The multilayered batt of  claim 1 , wherein the carded web comprises a plurality of binder fibers having a melting temperature of less than about 215° C., wherein the binder fibers connect at least some of the staple fibers to other staple fibers within each layer of the carded web. 
     
     
         10 . The multilayered batt of  claim 1 , wherein the continuous filament fibers comprise at least one of fiberglass, paramid, polyester, nylon, polybenzyimidazole, polybenzoxyphenol, and polyolefin. 
     
     
         11 . The multilayered batt of  claim 1 , wherein each layer of the one or more layers of the carded web is formed from a continuous carded web, the continuous carded web being folded onto itself to form each layer of the carded web. 
     
     
         12 . A cross-lapped multilayered batt having a Z-directional strength, the multilayered batt comprising:
 a plurality of layers of a carded web comprising staple fibers; and   a plurality of continuous filament fibers arranged between the layers of the carded web, the continuous filament fibers being spaced apart from one another,   wherein at least some of the staple fibers and some of the continuous filament fibers are mechanically entangled with one another through a thickness of the multilayered batt, so that the entangled staple fibers and the entangled continuous filament fibers extend along a Z direction of the multilayered batt.   
     
     
         13 . The multilayered batt of  claim 12 , wherein at least some of the continuous filament fibers are oriented in one of a linear pattern, a looped pattern, and a continuous wave-like pattern between the layers of the carded web. 
     
     
         14 . The multilayered batt of  claim 12 , wherein the carded web has a basis weight of from about 15 gsm to about 120 gsm. 
     
     
         15 . The multilayered batt of  claim 12 , further comprising at least one of a powder adhesive and a plurality of binder fibers having a melting temperature of less than about 215° C., wherein the binder fibers and the powder adhesive are each operative for adhering at least some of the staple fibers and continuous filament fibers to other staple fibers and other continuous filament fibers within each layer of the multilayered batt. 
     
     
         16 . A method of forming a multilayered batt, the method comprising:
 forming a fibrous composite, the fibrous composite comprising
 a carded web of staple fibers, the carded web having a machine direction, and 
 a plurality of continuous filament fibers positioned along a surface of the carded web, the continuous filament fibers being oriented so that the continuous filament fibers extend substantially along the machine direction of the carded web; 
   folding the fibrous composite onto itself to form an intermediate web including a plurality of fibrous composite layers; and   needlepunching the plurality of fibrous composite layers, so that at least some of the plurality of staple fibers and at least some of the plurality of continuous filament fibers of the fibrous composite layers are entangled with one another, and so that at least some of the entangled staple fibers and the entangled continuous filament fibers extend substantially along a Z direction of the multilayered batt.   
     
     
         17 . The method of  claim 16 , wherein the surface of the carded web includes an upper surface and a lower surface, and wherein at least some of the plurality of continuous fibers are positioned along the upper surface of the carded web and at least some other of the plurality of continuous filament fibers are positioned along the lower surface of the carded web. 
     
     
         18 . The method of  claim 16 , wherein the step of folding comprises using a cross-lapper. 
     
     
         19 . The method of  claim 16 , wherein the step of folding comprises folding the fibrous composite at a folding angle of from about 1 degree to about 45 degrees. 
     
     
         20 . The method of  claim 16 , wherein at least some of the continuous filament fibers are positioned in a linear pattern, a looped pattern, or a continuous wave-like pattern along the surface of the carded web.