Multicomponent self-bulking fibers

Abstract

The present invention provides multicomponent fibers designed to curl in response to external stimuli such as heat or moisture. The multicomponent fiber can have cross-sectional area comprising the first polymer component and the second polymer component, wherein the first polymer component and the second polymer component are configured in an eccentric sheath/core arrangement and wherein the core component has a non-circular shape. Also, the multicomponent fiber has a first cross-sectional center of mass and a cross-sectional periphery, the core component has a second cross-sectional center of mass; and the second cross-sectional center of mass is positioned from about 20 percent to about 70 percent of the distance from the first cross-sectional center of mass to a point on the cross-sectional periphery. Furthermore, the present disclosure provides a fabric including a plurality of multicomponent fibers designed to curl in response to external stimuli such as heat or moisture.

1 . A multicomponent fiber having a sheath/core arrangement, comprising:
 a sheath component comprising a first polymer component; and   a core component comprising a second polymer component;   wherein the core component has a first axis that is substantially perpendicular to a second axis, and wherein the first axis is longer than the second axis such that the core component has a non-circular shape;   wherein the multicomponent fiber has a first cross-sectional center of mass and a cross-sectional periphery;   wherein the core component has a second cross-sectional center of mass; and   wherein the second cross-sectional center of mass is positioned from about 20 percent to about 70 percent of the distance from the first cross-sectional center of mass to a point on the cross-sectional periphery.   
     
     
         2 . The multicomponent fiber of  claim 1 , wherein the fiber is selected from the group consisting of continuous filaments, staple fibers, electrospun fibers, spunbond, and meltblown fibers. 
     
     
         3 . The multicomponent fiber of  claim 1 , wherein the first polymer component is selected from the group consisting of a polyolefin, a polyester, a polyamide, and mixtures or blends thereof. 
     
     
         4 . The multicomponent fiber of  claim 1 , wherein the first polymer component is a polyamide. 
     
     
         5 . The multicomponent fiber of  claim 1 , wherein the second polymer component is selected from the group consisting of a polyolefin, a polyester, a polyamide, and mixtures or blends thereof. 
     
     
         6 . The multicomponent fiber of  claim 1 , wherein the second polymer component is a polyolefin. 
     
     
         7 . The multicomponent fiber of  claim 1 , wherein the length of the first axis is about 1.3 to about 2.8 times the length of the second axis. 
     
     
         8 . The multicomponent fiber of  claim 1 , wherein the core component has a substantially non-uniform, elongated shape. 
     
     
         9 . The multicomponent fiber of  claim 1 , wherein the core component has a substantially circular side connected to a substantially elliptical side. 
     
     
         10 . The multicomponent fiber of  claim 1 , wherein the multicomponent fiber has a cross-sectional area comprising about a 40:60 to about a 90:10 ratio of the sheath component to the core component. 
     
     
         11 . The multicomponent fiber of  claim 1 , wherein the multicomponent fiber has a first cross-sectional center of mass and a cross-sectional periphery, wherein the core component has a second cross-sectional center of mass, and wherein the second cross-sectional center of mass is positioned from about 30 percent to about 40 percent of the distance from the first cross-sectional center of mass to a point on the cross-sectional periphery. 
     
     
         12 . A fabric comprising a plurality of multicomponent fibers according to  claim 1 . 
     
     
         13 . The fabric of  claim 12 , wherein the fabric is a knit fabric or a woven fabric. 
     
     
         14 . The fabric of  claim 12 , wherein the fabric is formed form yarn including one or more of the multicomponent fibers. 
     
     
         15 . A yarn comprising one or more multicomponent fibers according to  claim 1 . 
     
     
         16 . The yarn of  claim 15 , wherein the yarn is a spun yarn or a continuous filament yarn. 
     
     
         17 . A method of forming a nonwoven fabric comprising:
 providing a plurality of multicomponent fibers according to  claim 1 ; and   bonding the plurality of multicomponent fibers.   
     
     
         18 . A method of forming a fabric comprising:
 providing a plurality of multicomponent fibers according to  claim 1 ; and   carding, knitting or weaving the plurality of multicomponent fibers to form the fabric.   
     
     
         19 . The method of  claim 18 , wherein the plurality of multicomponent fibers are in the form of one or both of spun yarns and continuous filament yarns.