Apparatus and method for producing two-sided patterned webs in registration

Abstract

An apparatus for casting a patterned surface on both sides of a web. The apparatus includes a first patterned roll; a second pattered roll; and a means for rotating the first and second patterned rolls such that their patterns are transferred to opposite sides of the web while it is in continuous motion. During this process, their patterns are maintained in continuous registration to within at least 100 microns, and preferably at least 20 microns.

1 . A method for imposing a pattern on both sides of a web comprising: 
 patterning a web between first and second patterned rolls, each roll having a pattern, such that the patterns are transferred to opposite sides of the web while it is in continuous motion, such that said patterns are maintained in continuous registration on said opposite sides of the web to within 100 microns.    
   
   
       2 . The method according to  claim 1  wherein the patterns are transferred to opposite sides of the web in registration to within 50 microns.  
   
   
       3 . The method according to  claim 2  wherein the patterns are transferred to opposite sides of the web in registration to within 20 microns.  
   
   
       4 . The method according to  claim 3  wherein the patterns are transferred to opposite sides of the web in registration to within 5 microns.  
   
   
       5 . The method according to  claim 1  further comprising: 
 introducing material capable of being patterned onto one side the web before the web encounters the first patterned roll, and    introducing material capable of being patterned onto the opposite side of the web before the web encounters the second patterned roll.    
   
   
       6 . The method according to  claim 1  further comprising: 
 introducing material capable of being patterned onto the first patterned roll, and    introducing material capable of being patterned onto the second patterned roll.    
   
   
       7 . The method according to  claim 5  wherein the at least one of the materials is a castable polymer precursor capable of being cured to solid polymer.  
   
   
       8 . The method according to  claim 7  further comprising the: 
 exposing at least one of the materials while in contact with at least one of the first and the second patterned rolls to heat.    
   
   
       9 . The method according to  claim 7  further comprising: 
 exposing at least one of the materials while in contact with at least one of the first and the second patterned rolls to radiant energy.    
   
   
       10 . The method according to  claim 9  wherein said exposing is performed using a source disposed within at least one of first and the second patterned rolls, and wherein at least one of first and the second patterned rolls has at least a portion that is transparent to the radiant energy.  
   
   
       11 . The method according to  claim 10  wherein the radiant energy is selected from the group consisting of infrared, visible, and ultraviolet radiation.