Multicomponent spunbond filaments having a melt-processable superabsorbent polymer core

Abstract

Multicomponent spunbond filaments including a core of superabsorbent polymer surrounded by a thermoplastic polymer sheath that is liquid permeable. The superabsorbent polymer in the filament core absorbs liquids that penetrate through liquid pathways defined in the filament sheath to the core. The spunbond filaments are suitable for forming an absorbent core of an article that absorbs liquids, such as a disposable hygienic article used for absorbing aqueous body fluids.

1 . A non-woven web formed from a plurality of multicomponent filaments, each filament comprising: 
 a liquid-pervious sheath region comprising a melt-processable thermoplastic polymer; and    a core region encased within said sheath region, said core region comprising a melt-processable superabsorbent polymer capable of absorbing liquid that penetrates through said sheath region to said core region.    
   
   
       2 . The nonwoven web of  claim 1  wherein said superabsorbent polymer is an acrylate-based material.  
   
   
       3 . The nonwoven web of  claim 2  wherein said acrylate-based material is polyacrylate.  
   
   
       4 . The nonwoven web of  claim 1  wherein said sheath region includes a plurality of liquid pathways through which liquid penetrates to said core region.  
   
   
       5 . The nonwoven web of  claim 3  wherein said plurality of liquid pathways are formed by adding a pathway-promoting agent to said thermoplastic polymer when said plurality of multicomponent filaments are formed.  
   
   
       6 . The nonwoven web of  claim 1  wherein said core region has a length, said superabsorbent polymer being distributed along said length in a plurality of discrete portions with adjacent ones of said plurality of discrete portions separated by one of a plurality of voids into which said superabsorbent polymer may expand after the liquid is absorbed.  
   
   
       7 . The nonwoven web of  claim 1  wherein said superabsorbent polymer has an absorbency exceeding about 50 grams of saline per gram of superabsorbent polymer.  
   
   
       8 . The nonwoven web of  claim 1  wherein said superabsorbent polymer comprises a superabsorbent polymer matrix containing at least one of a plurality of superabsorbent polymer granules and a plurality of superabsorbent polymer agglomerates.  
   
   
       9 . The nonwoven web of  claim 1  wherein said melt-processable superabsorbent polymer comprises at least 50 weight percent of each of the plurality of filaments.  
   
   
       10 . A product formed from the nonwoven web of  claim 1 .  
   
   
       11 . The product of  claim 10  wherein said product is a hygienic article.  
   
   
       12 . A method of manufacturing a nonwoven web, comprising: 
 heating a thermoplastic polymer to a flowable state;    heating a superabsorbent polymer to a flowable state;    combining the thermoplastic polymer and the superabsorbent polymer to form a plurality of multicomponent filaments each having a liquid-pervious sheath region including the thermoplastic polymer and a core region including the superabsorbent polymer; and    collecting the plurality of multicomponent filaments to form a nonwoven web.    
   
   
       13 . The method of  claim 12  further comprising: 
 adding a concentration of superabsorbent polymer granules to the superabsorbent polymer.    
   
   
       14 . The method of  claim 12  further comprising: 
 adding a concentration of superabsorbent polymer agglomerates to the superabsorbent polymer.    
   
   
       15 . The method of  claim 12  wherein combining the thermoplastic polymer and the superabsorbent polymer further comprises: 
 distributing the superabsorbent polymer along a length of each of the plurality of multicomponent filaments in a plurality of discrete portions with adjacent ones of the plurality of discrete portions being separated by one of a plurality of voids into which the superabsorbent polymer may expand after liquid is absorbed.    
   
   
       16 . The method of  claim 12  wherein combining the thermoplastic polymer and the superabsorbent polymer further comprises: 
 forming a plurality of liquid pathways extending through the sheath region.    
   
   
       17 . The method of  claim 16  wherein forming the plurality of pathways further comprises: 
 adding a pathway-promoting agent to the thermoplastic polymer.