Cross-direction elasticized composite material and method of making it

Abstract

A cross-directional elasticized composite includes a facing layer and a plurality of elastic filaments disposed in the cross direction. A method for making the cross-direction elasticized composite by continuously disposing molten elastic filaments on the facing layer and in the cross direction, is also provided.

1 . A neck-bonded laminate, comprising: 
 a necked nonwoven web neck-stretched in a machine direction to cause narrowing in a cross direction perpendicular to the machine direction; and    a plurality of elastic filaments joined to the necked nonwoven web and disposed significantly in the cross direction.    
   
   
       2 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are directly bonded to the necked nonwoven web by melt bonding.  
   
   
       3 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are spaced apart and nonintersecting with respect to each other.  
   
   
       4 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are substantially parallel to each other.  
   
   
       5 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are disposed between about −30 degrees and about +30 degrees relative to the cross direction.  
   
   
       6 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are disposed between about −15 degrees and about +15 degrees relative to the cross direction.  
   
   
       7 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments are disposed between about −5 degrees and about +5 degrees relative to the cross direction.  
   
   
       8 . The neck-bonded laminate of  claim 1 , wherein the necked nonwoven web is stretched to about 1.1 to about 1.6 times an initial length in the machine direction.  
   
   
       9 . The neck-bonded laminate of  claim 1 , wherein the necked nonwoven web is stretched to about 1.2 to about 1.5 times an initial length in the machine direction.  
   
   
       10 . The neck-bonded laminate of  claim 1 , wherein the necked nonwoven web comprises a fibrous web selected from the group consisting of spunbond webs, meltblown webs, bonded carded webs, and combinations thereof.  
   
   
       11 . The neck-bonded laminate of  claim 1 , wherein the elastic filaments terminate at longitudinal side edges of the necked nonwoven web.  
   
   
       12 . A method of making an elastic composite material, comprising the steps of: 
 feeding a facing layer to a first mandrel at an angle of about 15 to about 75 degrees relative to a longitudinal axis of the first mandrel;    rotating the first mandrel in a first direction around the axis, while conveying the facing layer axially forward, causing the facing layer to wrap around the first mandrel in a spiral fashion;    conveying the facing material beyond a terminal end of the first mandrel, and between an extrusion die and an inner surface of a second mandrel;    rotating the extrusion die in a second direction opposite the first direction while simultaneously extruding elastic polymer filaments from the extrusion die onto the facing layer, to form a laminate; and    severing the elastic filaments along longitudinal side edges of the facing layer to form the elastic composite material.    
   
   
       13 . The method of  claim 12 , wherein the facing layer is fed to the first mandrel at an angle of about 30 to about 60 degrees relative to the axis.  
   
   
       14 . The method of  claim 12 , wherein the facing layer is fed to the first mandrel at an angle of about 40 to about 50 degrees relative to the axis.  
   
   
       15 . The method of  claim 12 , wherein the elastic polymer filaments are extruded onto the facing layer at an angle between about −30 degrees and about +30 degrees relative to a cross direction of the facing layer.  
   
   
       16 . The method of  claim 15 , wherein the elastic polymer filaments are extruded onto the facing layer at an angle of about −15 degrees to about +15 degrees relative to the cross direction.  
   
   
       17 . The method of  claim 15 , wherein the elastic polymer filaments are extruded onto the facing layer at an angle of about −5 degrees to about +5 degrees relative to the cross direction.  
   
   
       18 . The method of  claim 12 , further comprising the step of melt bonding the elastic polymer filaments to the facing layer.  
   
   
       19 . The method of  claim 12 , further comprising the step of passing the laminate around a terminal edge of the second mandrel to an outer surface of the second mandrel before severing the elastic filaments.  
   
   
       20 . The method of  claim 12 , wherein the facing layer comprises a necked nonwoven web.  
   
   
       21 . The method of  claim 12 , wherein the elastic filaments are spaced apart and nonintersecting relative to each other.  
   
   
       22 . The method of  claim 12 , wherein the first mandrel comprises a plurality of axially disposed conveyor belts for conveying the facing material axially forward.  
   
   
       23 . The method of  claim 19 , further comprising the steps, after severing the elastic filaments, of: 
 a) causing a first edge of the laminate to leave the second mandrel immediately after being drawn around the terminal edge of the second mandrel; and    b) causing a second edge of the laminate to leave the second mandrel after traversing the second mandrel with one spiral wrap after being drawn around the terminal edge of the second mandrel.    
   
   
       24 . A method of making an elastic composite material, comprising the steps of: 
 feeding a facing layer to an outer surface of a first cylindrical mandrel at an angle relative to a longitudinal axis of the mandrel;    rotating the first mandrel in a first direction around the axis, while conveying the facing layer axially forward, causing the facing layer to wrap around the mandrel in a spiral fashion;    conveying the facing material between an extrusion die and an inner surface of a second cylindrical mandrel that is concentric with the first cylindrical mandrel;    rotating the extrusion die in a second direction opposite the first direction while simultaneously extruding spaced-apart elastic filaments from the extrusion die onto the facing layer, to form a laminate; and    severing the elastic filaments along edges of the laminate to form the elastic composite material.    
   
   
       25 . The method of  claim 24 , wherein the facing layer is fed to the outer surface of the first cylindrical mandrel at a linear velocity V, the first cylindrical mandrel has an outer diameter D 0 , and the extrusion die is rotated at a speed N 0 , in revolutions per minute, defined by the equation:  
     
       
         
           
             
               N 
               0 
             
             = 
             
               
                 V 
                 ⁢ 
                 
                   2 
                 
               
               
                 Π 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   D 
                   0 
                 
               
             
           
         
       
     
   
   
       26 . The method of  claim 24 , wherein the first cylindrical mandrel comprises a plurality of axially disposed conveyor belts for conveying the facing material forward.  
   
   
       27 . The method of  claim 26 , wherein the facing layer is fed to the outer surface of the first cylindrical mandrel at a linear velocity V, and the axially disposed conveyor belts move along the axis at a speed V b  defined by the equation:  
     
       
         
           
             
               V 
               b 
             
             = 
             
               V 
               
                 2 
               
             
           
         
       
     
   
   
       28 . The method of  claim 24 , wherein the first cylindrical mandrel is disposed partially within the second cylindrical mandrel.  
   
   
       29 . The method of  claim 24 , further comprising the step of passing the laminate around a terminal edge of the second cylindrical mandrel to an outer surface of the second cylindrical mandrel before severing the elastic filaments.