Process for producing a nonwoven polyester staple fiber fabric

Abstract

Polyester staple fibers containing a polymeric blend of 0.5 to 15 mass % of a polyolefinic polymer with a matrix polyester polymer, 50% or more of the surface area of each fiber being formed by the polymeric blend, are useful for forming a nonwoven fabric with soft hand and a uniform texture by using various web-forming methods, for example, an air laid, wet laid or carding method.

1 - 12 . (canceled)  
   
   
       13 . A process for producing a nonwoven polyester staple fiber fabric comprising; 
 preparing polyester staple fibers comprising a polymeric blend comprising 85 to 95.5% by mass of matrix polyester polymer and 0.5 to 15% by mass of a polyolefinic polymer mixed with and dispersed in the matrix polyester polymer, at least the surface of each fiber being formed by the polymeric blend; and    forming the polymeric blend staple fibers into a nonwoven fabric by an air-laid web-forming method.    
   
   
       14 . The process for producing a nonwoven polyester staple fiber fabric as claimed in  claim 13 , wherein the polyolefinic polymer comprises at least one member selected from polyethylene, polypropylene, ethylene-propylene copolymers and polyethylene copolymers and polypropylene copolymers in which at least one ethylenically unsaturated monomer different from ethylene and propylene is block-copolymerized or graft-copolymerized.  
   
   
       15 . The process for producing a nonwoven polyester staple fiber fabric as claimed in  claim 13 , wherein the matrix polyester polymer is selected from polyalkylene terephthalates and polyalkylene terephthalate-isophthalate copolymers.  
   
   
       16 . The process for producing a nonwoven polyester staple fiber fabric as claimed in any one of  claims 13  to  15 , wherein the polyester staple fibers have a degree of crystallization of 20% or less or a birefringence of 0.05 or less.  
   
   
       17 . The process for producing a nonwoven polyester staple fiber fabric as claimed in any one of  claims 13  to  15 , wherein the polyester staple fibers have a concentric or eccentric core-in-sheath conjugate structures in which the sheath section is formed from the polymeric blend, and core section is formed from a member selected from polyesters and polyamides.  
   
   
       18 . The process for producing a nonwoven polyester staple fiber fabric as claimed in any one of  claims 13  to  15 , wherein the polyester staple fibers have a fiber length of 2 to 30 mm, and crimps in a number of crimp of 3 to 13 crimps/25 mm and a percentage of crimp of 3 to 15%.  
   
   
       19 . The process for producing a nonwoven polyester staple fiber fabric as claimed in any one of  claims 13  to  15 , wherein the nonwoven fabric has a percentage of non-opened fibers of 5% or less.  
   
   
       20 . The process for producing a nonwoven polyester staple fiber fabric as claimed in any one of  claims 13  to  15 , wherein the nonwoven fabric has a bending resistance of 70 mm or less, as determined by the cantilever method.