Nonwoven fabric and method of forming the same

Abstract

A nonwoven fabric including a plurality of endless crimpable multicomponent filaments, a plurality of loops that extend only in a direction out of a base plane of the nonwoven fabric, the base plane being an imaginary plane through the nonwoven fabric that extends in a machine direction and a cross direction of the nonwoven fabric, each of the plurality of loops made up of at least three of the plurality of filaments, the nonwoven fabric being devoid of loops that extend within the base plane, a plurality of bows that extend in directions within and out of the base plane of the nonwoven fabric, each of the plurality of bows made up of no more than one of the plurality of filaments, and a plurality of fused inter-filamentary conjunctions between at least some of the plurality of filaments.

1 . A nonwoven fabric comprising:
 a plurality of endless crimpable multicomponent filaments;   a plurality of loops that extend only in a direction out of a base plane of the nonwoven fabric, the base plane being an imaginary plane through the nonwoven fabric that extends in a machine direction and a cross direction of the nonwoven fabric, each of the plurality of loops made up of at least three of the plurality of filaments, the nonwoven fabric being devoid of loops that extend within the base plane;   a plurality of bows that extend in directions within and out of the base plane of the nonwoven fabric, each of the plurality of bows made up of no more than one of the plurality of filaments; and   a plurality of fused inter-filamentary conjunctions between at least some of the plurality of filaments.   
     
     
         2 . The nonwoven fabric of  claim 1 , wherein the fused inter-filamentary conjunctions are bonding impressions. 
     
     
         3 . The nonwoven fabric of  claim 1 , wherein the fused inter-filamentary conjunctions are bonding points. 
     
     
         4 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a bulkiness of 70 kg/m 3  or less. 
     
     
         5 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a Handle-O-Meter value in the machine direction of 2 g to 15 g. 
     
     
         6 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a resilience of at least 10%. 
     
     
         7 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a machine direction elongation at 5 N force of at least 15%. 
     
     
         8 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a machine direction elongation at 5 N force of at least 20%. 
     
     
         9 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a machine direction elongation at 5 N force of not more than 100%. 
     
     
         10 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a machine direction elongation at 5 N force of not more than 80%. 
     
     
         11 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a machine direction elongation at 5 N force of not more than 65%. 
     
     
         12 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a normalized machine direction tensile strength of at least 0.26 N·m 2 /g·cm. 
     
     
         13 . The nonwoven fabric of  claim 1 , wherein the nonwoven fabric has a cross direction tensile strength of at least 2 N/cm. 
     
     
         14 . The nonwoven fabric of  claim 1 , wherein the plurality of filaments have an eccentric core-sheath or side by side cross-section. 
     
     
         15 . The nonwoven fabric of  claim 1 , wherein each of the plurality of filaments comprise a first polymer and a second polymer, the second polymer being a bonding polymer. 
     
     
         16 . The nonwoven fabric of  claim 15 , wherein a difference between the melt temperature of the first polymer and the melt temperature of the second polymer is at least 5° C. 
     
     
         17 . The nonwoven fabric of  claim 15 , wherein the bonding polymer comprises a polymer selected from the group consisting of: polyolefins polyester grades, and copolymers or blends thereof. 
     
     
         18 . The nonwoven fabric of  claim 15 , wherein the first polymer comprises a polymer selected from the group consisting of: polyolefins, polyesters, and copolymers or blends thereof. 
     
     
         19 . The nonwoven fabric of  claim 15 , wherein the first and second polymers form bicomponent polymer pairs selected from the group consisting of: PP1/PP2, PP/PE, PET/PE, PET/PP, PET/PET, PLA/PLA, PLA/PE and PLA/PP, wherein PP1, PP2, PP, PE, PET and PLA are virgin polymer, copolymer or blends of thereof, and where PP1 is a first type of polypropylene, PP2 is a second type of polypropylene, PE is polyethylene, PET is polyethylene terephthalate and PLA is polylactic acid. 
     
     
         20 . The nonwoven fabric of  claim 1 , wherein the plurality of endless crimpable multicomponent filaments form at least one layer, and the nonwoven fabric comprises at least one second layer. 
     
     
         21 . A nonwoven fabric having a Handle-O-Meter value in the machine direction from 2 g to 6 g, a Handle-O-Meter value in the cross direction from 1 g to 5 g, a bulkiness of 70 kg/m 3  or less, a machine direction elongation at 5 N force in a range of 30% to 100%, and a cross direction elongation at 5 N force in a range of 25% to 60%. 
     
     
         22 . A method of forming a nonwoven fabric, comprising
 A. forming a nonwoven batt formed of endless partially irregularly crimped multicomponent filaments;   B. subjecting the nonwoven batt to thermal pre-consolidation to form fused inter-filamentary conjunctions, wherein at least some of the filaments become more irregularly crimped during the step of forming the batt and/or the step of thermal pre-consolidation; and   C. hydroentangling the pre-consolidated batt to form a nonwoven fabric having a plurality of loops that extend only in a direction out of a base plane of the nonwoven fabric, the base plane being an imaginary plane through the nonwoven fabric that extends in a machine direction and a cross direction of the nonwoven fabric, each of the plurality of loops made up of at least three of the plurality of filaments, the nonwoven fabric being devoid of loops that extend within the base plane, and a plurality of bows that extend in directions within and out of the base plane of the nonwoven fabric, each of the plurality of bows made up of no more than one of the plurality of filaments.   
     
     
         23 . The method of  claim 22 , wherein the thermal pre-consolidation comprises a first pre-consolidation step and a second pre-consolidation step. 
     
     
         24 . The method of  claim 23 , wherein the first and second pre-consolidation steps are performed using one or more of the following: compact rollers, calender rolls, hot air knife, and hot air oven.