Nonwoven fabrics and methods of making and using same

Abstract

Substantially compostable nonwoven fabrics comprising staple fibers made from natural cellulosic fibers optionally mixed with other natural, man-made or synthetic fibers are described. Also described are methods of preparing such nonwoven fabrics that can include the steps of at least one of needle punching and/or hydroentangling and optionally resin bonding and/or thermal bonding. The compostable, or substantially compostable nonwoven fabrics disclosed herein provide improved durability over conventional nonwoven fabrics.

What is claimed is: 
     
         1 . A nonwoven fabric, comprising: a needle punched and/or hydroentangled web of nonwoven staple fibers having a first fiber component comprising natural cellulosic fibers with fiber lengths less than about 26 mm. 
     
     
         2 . The nonwoven fabric of  claim 1 , wherein the web further comprises a second fiber component comprising fiber lengths greater than about 30 mm. 
     
     
         3 . The nonwoven fabric of  claim 2 , wherein the second fiber component is selected from the group consisting of PLA, PHA, a man-made cellulosic fiber, a bicomponent fiber, and any combination thereof. 
     
     
         4 . The nonwoven fabric of  claim 1 , wherein the natural cellulosic fibers are more than about 50% by weight based on the total weight of the nonwoven fabric. 
     
     
         5 . The nonwoven fabric of  claim 1 , wherein the web is needle punched and/or hydroentangled at high pressure to reach an air permeability of 150 cfm or less and a bursting strength of 30 pounds or higher, at a weight of at least 100 g/m 2 . 
     
     
         6 . The nonwoven fabric of  claim 1 , wherein the natural cellulosic fibers are selected from the group consisting of cotton, kenaf, hemp, flax, ramie, pineapple, coir, and any combination thereof. 
     
     
         7 . The nonwoven fabric of  claim 1 , further comprising an acrylic or a polyurethane resin at from about 1% to about 15% by weight based on the total weight of the nonwoven fabric. 
     
     
         8 . The nonwoven fabric of  claim 1 , wherein the fabric comprises one or more additional webs of nonwoven staple fibers. 
     
     
         9 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric comprises a first web layer, a third web layer, and a second web layer disposed between the first web layer and the third web layer, wherein the web layers are needle punched and/or hydroentangled, and at least one of the web layers is thermally bonded and chemically bonded. 
     
     
         10 . The nonwoven fabric of  claim 9 , wherein each of the first web layer and the third web layer comprises a splittable bicomponent staple fiber such that the entire content of the splittable bicomponent staple fiber comprises from about 25% to about 50% by weight of the total weight of the nonwoven fabric. 
     
     
         11 . The nonwoven fabric of  claim 10 , wherein the splittable bicomponent staple fiber has a cross-section selected from the group consisting of side-by-side, tipped trilobal, segmented pie, segmented ribbon, islands in the sea, and any combination thereof. 
     
     
         12 . The nonwoven fabric of  claim 9 , wherein each of the first web layer and the third web layer is a spunbonded web comprising a splittable bicomponent fiber and the second web layer comprises a staple fiber bonded together mechanically by needle punching and/or hydroentangling. 
     
     
         13 . The nonwoven fabric of  claim 12 , wherein the splittable bicomponent fiber comprises from about 25% to about 50% by weight of the total weight of the fibers comprising the spunbonded web. 
     
     
         14 . The nonwoven fabric of  claim 12 , wherein at least a portion of the splittable bicomponent fibers of the spunbonded web are partially split and are entangled with at least a portion of the staple fibers of the second web layer. 
     
     
         15 . A bag comprising the nonwoven fabric of  claim 1 . 
     
     
         16 . A method for preparing a nonwoven fabric, comprising: needle punching and/or hydroentangling a web of nonwoven staple fibers to form an interlaced fibrous structure, wherein the web comprises a first fiber component comprising natural cellulosic fibers with fiber lengths less than about 26 mm. 
     
     
         17 . The method of  claim 16 , wherein before needle punching and/or hydroentangling the web of nonwoven staple fibers is prepared by producing a carded matrix of a fiber on a web, the fiber having a substantially uniform basis weight; and cross-lapping the carded matrix. 
     
     
         18 . The method of  claim 16 , further comprising bonding the interlaced fibrous structure to form a bonded fibrous structure. 
     
     
         19 . The method of  claim 16 , further comprising hydroentangling and calendering the bonded fibrous structure to provide a surface effect to the fabric. 
     
     
         20 . The method of  claim 16 , wherein bonding the interlaced fibrous structure comprises thermally bonding and/or chemically bonding. 
     
     
         21 . The method of  claim 16 , wherein the web comprises a second fiber component, the second fiber component being selected from the group consisting of PLA, PHA, a man-made cellulosic fiber, a bicomponent fiber, and any combination thereof. 
     
     
         22 . The method of  claim 16 , wherein the web is needle punched and/or hydroentangled at high pressure to reach an air permeability of 150 cfm or less and a bursting strength of 30 pounds or higher, at a weight of at least 100 g/m 2 . 
     
     
         23 . The method of  claim 16 , wherein the natural cellulosic fibers are selected from the group consisting of cotton, kenaf, hemp, flax, ramie, pineapple, coir, and any combination thereof.