Method of producing low cost elastic web

Abstract

A method for producing nonwoven webs, laminates, and composites thereof includes activating by elongation in at least a two-stage process wherein the first elongation is in substantially the same direction and to substantially the same degree as the second elongation.

1 . A method of activating a nonwoven web, laminate, or composite thereof comprising: 
 elongating a nonwoven web, laminate, or composite thereof precursor material a first time to provide a first elongated material; and    elongating the first elongated material a second time in substantially the same direction and to substantially the same degree as the first elongation.    
   
   
       2 . The method of  claim 1 , wherein the nonwoven web, laminate, or composite thereof contains fibers selected from the group consisting of polyethylene, polypropylene, acrylic, polyamide, polyester, rayon, cellulose, nylon fibers, and combinations and composites thereof.  
   
   
       3 . The method of  claim 1 , wherein the nonwoven material in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of 20 or less grams per square meter.  
   
   
       4 . The method of  claim 1 , wherein the nonwoven material in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of 25 or less grams per square meter.  
   
   
       5 . The method of  claim 1 , wherein the laminate comprises at least one elastic film or sheet and at least one nonwoven web.  
   
   
       6 . A method for activating a nonwoven web, laminate, or composite thereof precursor material comprising: 
 elongating the nonwoven web, laminate, or composite thereof precursor material a first time by a first means for elongating to provide a first elongated material; and    elongating the first elongated material a second time by a second means for elongating, the second means for elongating being in substantially the same direction and to substantially the same degree as in the first means for elongating.    
   
   
       7 . The method of  claim 6 , wherein said first and second means for elongating comprises sets of intermeshing gear rollers with ribs, grooves, or teeth parallel to the axis of rotation of the intermeshing gear rollers.  
   
   
       8 . The method of  claim 6 , wherein said first and second means for elongating comprises sets of intermeshing gear rollers with ribs, grooves, or teeth perpendicular to the axis of rotation of the intermeshing gear rollers.  
   
   
       9 . The method of  claim 6 , wherein said first and second means for elongating each comprises a first pair and a second pair of driven rollers with means for frictionally engaging the nonwoven web, laminate, or composite thereof, wherein the second pair of driven rollers is operated at a faster linear circumferential speed than is the first pair of driven rollers.  
   
   
       10 . An activated nonwoven web, laminate, or composite thereof made by the method of  claim 1 .  
   
   
       11 . The activated nonwoven web, laminate, or composite of  claim 10 , wherein the nonwoven web in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of 20 or less grams per square meter.  
   
   
       12 . The activated nonwoven web, laminate, or composite of  claim 11 , wherein elongating the first and second time comprises elongating to an activation depth of about 0.2 inches each time.  
   
   
       13 . The activated nonwoven web, laminate, or composite of  claim 12 , having a peak force of at least 8.00 Newtons per inch of sample width.  
   
   
       14 . The activated nonwoven web, laminate, or composite of  claim 12 , having a knee elongation of at least 109% measured at the point in the stress/strain curve at which the rate of increase of tensile force with elongation reaches 0.1 Newtons per percent elongation.  
   
   
       15 . The activated nonwoven web, laminate, or composite of  claim 11 , wherein elongating the first and second time comprises elongating to an activation depth of about 0.175 inches each time.  
   
   
       16 . The activated nonwoven web, laminate, or composite of  claim 15 , having a peak force of at least 11.00 Newtons per inch of sample width.  
   
   
       17 . The activated nonwoven web, laminate, or composite of  claim 15 , having a knee elongation of at least 93% measured at the point in the stress/strain curve at which the rate of increase of tensile force with elongation reaches 0.1 Newtons per percent elongation.  
   
   
       18 . The activated nonwoven web, laminate, or composite of  claim 10 , wherein the nonwoven web in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of 25 or less grams per square meter.  
   
   
       19 . The activated nonwoven web, laminate, or composite of  claim 18 , wherein elongating the first and second time comprises elongating to an activation depth of about 0.2 inches each time.  
   
   
       20 . The activated nonwoven web, laminate, or composite of  claim 19 , having a peak force of at least 10 Newtons per inch of sample width.  
   
   
       21 . The activated nonwoven web, laminate, or composite of  claim 19 , having a knee elongation of at least 102% measured at the point in the stress/strain curve at which the rate of increase of tensile force with elongation reaches 0.1 Newtons per percent elongation.  
   
   
       22 . The activated nonwoven web, laminate, or composite of  claim 18 , wherein elongating the first and second time comprises elongating to an activation depth of about 0.175 inches each time.  
   
   
       23 . The activated nonwoven web, laminate, or composite of  claim 22 , having a peak force of at least 15 Newtons per inch of sample width.  
   
   
       24 . The activated nonwoven web, laminate, or composite of  claim 22 , having a knee elongation of at least 86% measured at the point in the stress/strain curve at which the rate of increase of tensile force with elongation reaches 0.1 Newtons per percent elongation.  
   
   
       25 . An absorbent article comprising the activated nonwoven web, laminate, or composite thereof of  claim 10 .  
   
   
       26 . The absorbent article in  claim 25 , wherein the nonwoven web in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of less than or equal to 20 grams per square meter.  
   
   
       27 . The absorbent article in  claim 25 , wherein the nonwoven web in the nonwoven web, laminate, or composite thereof precursor material has a basis weight of less than or equal to 25 grams per square meter.  
   
   
       28 . The absorbent article in  claim 25 , wherein the laminate comprises at least an elastic film and a nonwoven web.