Bicomponent fibers including ethylene/alpha-olefin interpolymers

Abstract

Provided are bicomponent fibers. The bicomponent fiber comprises a first region and a second region. The first region comprises a first ethylene/alpha-olefin interpolymer, and the second region comprises a second ethylene/alpha-olefin interpolymer. The first ethylene/alpha-olefin interpolymer has a highest peak melting temperature (Tm) less than 130° C. and at least 3.5° C. greater than a highest peak melting temperature of the second ethylene/alpha-olefin interpolymer. The bicomponent fibers can be used for forming nonwovens that in aspect have improved tensile strength, elongation at break, and/or abrasion resistance.

1 . A bicomponent fiber comprising:
 a first region and a second region;   the first region comprising a first ethylene/alpha-olefin interpolymer having a highest peak melting temperature (Tm) of less than 130° C. when measured by DSC;   the second region comprising a second ethylene/alpha-olefin interpolymer having a density less than a density of the first ethylene/alpha-olefin interpolymer composition;   wherein the highest peak melting temperature (Tm) of the first ethylene/alpha-olefin interpolymer is at least 3.5° C. greater than a highest peak melting temperature (Tm) of the second ethylene/alpha-olefin interpolymer, where highest peak melting temperature (Tm) is measured by DSC;   wherein the first region and second region are arranged in a core-sheath configuration.   
     
     
         2 . The bicomponent fiber of  claim 1 , wherein the first ethylene/alpha-olefin interpolymer has a highest peak crystallization temperature (Tc) at least 3.5° C. greater than a highest peak crystallization temperature (Tc) of the second ethylene/alpha-olefin interpolymer, where highest peak crystallization temperature (Tc) is measured by DSC. 
     
     
         3 . The bicomponent fiber of  claim 1 , wherein the density of the first ethylene/alpha-olefin interpolymer is at least 0.022 g/cm 3  greater than the density of the second ethylene/alpha-olefin interpolymer. 
     
     
         4 . A nonwoven formed from the bicomponent fiber of  claim 1 , wherein the nonwoven has one or more of the following properties: a fiber denier equal to or less than 1.5 g/9000 m; a tensile strength in the machine direction greater than 11.0 Newton per one inch at 20 gsm of the nonwoven; an elongation at break in the machine direction greater than 100% at 20 gsm of the nonwoven; and an abrasion resistance in the machine direction of less than 0.18 mg/cm 2  at 20 gsm of the nonwoven. 
     
     
         5 . A nonwoven formed from the bicomponent fiber of  claim 1 , wherein the nonwoven comprises at least 12 wt. % of the combined first ethylene/alpha-olefin interpolymer and second ethylene/alpha-olefin interpolymer at a temperature range of from 40.0° C. to 68.0° C. (WT 40-68° C. ) on an elution profile via improved comonomer composition distribution (ICCD) procedure. 
     
     
         6 . A nonwoven formed from the bicomponent fiber of  claim 1 , wherein the nonwoven has a fiber denier equal to or less than 1.5 g/9000 m; a tensile strength in the machine direction greater than 11.0 Newton per one inch at 20 gsm of the nonwoven; an elongation at break in the machine direction greater than 100% at 20 gsm of the nonwoven; and an abrasion resistance in the machine direction of less than 0.18 mg/cm 2  at 20 gsm of the nonwoven.