Square hollow fiber

Abstract

A hollow polymeric fiber includes: a tetragonal shape sectional area having four corner points and four edges. The four corner points form a square. All four edges are concave or straight. The fiber has a cross sectional area hollowness ranging from 12 to 25%. The fiber has a titer in a range of from 4 to 16 dtex.

1 . A hollow polymeric fiber, comprising:
 a tetragonal shape sectional area having four corner points and four edges,   wherein the four corner points form a square,   wherein all four edges are concave or straight,   wherein the fiber has a cross sectional area hollowness ranging from 12 to 25%, and   wherein the fiber has a titer in a range of from 4 to 16 dtex.   
     
     
         2 . The hollow polymeric fiber according to  claim 1 , wherein a shape of each corner resembles an acute angle, or a right angle with straight or concave legs (arrow tip). 
     
     
         3 . The hollow polymeric fiber according to  claim 1 , wherein a diameter of an outer circle of the tetragonal shape is in a range of from 10 μm to 100 μm. 
     
     
         4 . The hollow polymeric fiber according to  claim 1 , wherein the fiber is prepared by polymer melt or solution spinning through a spinneret comprising a pattern of orifices,
 wherein one single fiber is formed by passing a polymer melt though an arrangement of four slots, and   wherein each slot of the four slots forming one fiber has a shape that resembles an acute angle, or a right angle with straight or concave legs.   
     
     
         5 . The hollow polymeric fiber according to  claim 4 , wherein the fiber is prepared by melt or solution spinning through the spinneret comprising the pattern of orifices, and
 wherein the fibers exiting the spinneret are subjected to a one step drawing process.   
     
     
         6 . The hollow polymeric fiber according to  claim 4 , wherein a length of two legs of each slot is in a range of 0.4 to 0.6 mm and a width of each leg is in a range of 0.08 to 0.13 mm. 
     
     
         7 . The hollow polymeric fiber according to  claim 4 , wherein a ratio of a length to a width of legs of each of the slots is in a range of 4:1 to 6:1. 
     
     
         8 . The hollow polymeric fiber according to  claim 1 , wherein the fiber is comprised of thermoplastic polymers. 
     
     
         9 . A fiber composition, comprising:
 at least one of the fiber of  claim 1 ; and   at least one fiber which is selected from a group consisting of:
 fibers having different denier values compared to the fiber according to  claim 1 , or 
 fibers having different shapes compared to the fiber according to  claim 1 . 
   
     
     
         10 . A nonwoven fabric, comprising:
 the fiber according to  claim 1 .   
     
     
         11 . A method for preparing a nonwoven fabric, comprising:
 employing fibers comprising at least one hollow polymeric fiber according to  claim 1 .   
     
     
         12 . The method according to  claim 11 , wherein the nonwoven fabric is prepared by polymer melt or solution spinning of the fibers through a spinneret comprising a pattern of orifices,
 wherein one single fiber is formed by passing the polymer melt though an arrangement of four slots, and   wherein each slot of the four slots forming one fiber has a shape that resembles an acute angle or a right angle with straight or concave legs.   
     
     
         13 . The nonwoven fabric according to  claim 10 , wherein the fabric comprises a tufted nonwoven fabric. 
     
     
         14 . The nonwoven fabric according to  claim 10 , further comprising a tuft-backing containing the fiber. 
     
     
         15 . A carpet tile, comprising:
 the hollow polymeric fiber according to  claim 1 .   
     
     
         16 . The hollow polymeric fiber according to  claim 3 , wherein the diameter of the outer circle of the tetragonal shape is in a range of from 15 μm to 50 μm. 
     
     
         17 . The hollow polymeric fiber according to  claim 4 , wherein each of the four slots forms an arrow tip. 
     
     
         18 . The hollow polymeric fiber according to  claim 7 , wherein the ratio of the length to the width of legs of each of the slots is in a range of 4.5:1 to 5.5:1. 
     
     
         19 . The hollow polymeric fiber according to  claim 8 , wherein the thermoplastic polymers are selected from a group consisting of: polyesters, polyolefines, polyamides, polylactates, copolymers derived thereof, and mixtures thereof. 
     
     
         20 . The fiber composition according to  claim 9 , wherein the fibers having different denier values are in a top-down arrangement, or the fibers having different shapes are in a top-down arrangement.