Method for forming multilayer release liners and liners formed thereby

Abstract

Disclosed herein is a multilayer silicone release surface comprising a backing, a support layer on the backing, and a silicone layer of the support layer. The various layers of the multilayer release surface are deposited substantially simultaneously, as for example by a dual die or using curtain coating techniques.

1 . A method of increasing the coating gap for a die-coated silicone-containing layer, comprising: 
 determining the maximum coating gap where a substantially defect free release layer is formed on a coated paper;    increasing the coating gap; and    applying a vacuum upstream and adjacent to a coating bead formed by the die.    
     
     
         2 . A method for applying a silicone-containing release layer to a backing, comprising: 
 moving the backing along a selected path;    providing a die at a selected spacing from the backing and expressing the silicone-containing release layer from the die, the spacing between the die and the backing being selected to achieve an acceptably low dispersion of the release layer into the backing and an unstable feed of the release coating upstream of the die; and    applying a vacuum in proximity to the backing and the die at locations upstream of the die for stabilizing the bead of the release layer while maintaining an acceptably low dispersion of the release layer in the backing.    
     
     
         3 . The method of  claim 2 , wherein the vacuum is applied at between 1-250 cm of H 2 O.  
     
     
         4 . The method of  claim 3 , wherein the vacuum is applied at between 25-200 cm of H 2 O.  
     
     
         5 . The method of  claim 3 , wherein the vacuum is applied at between 50-75 cm of H 2 O.  
     
     
         6 . An apparatus for applying the release layer to a backing, comprising: 
 means for moving the backing along a selected path;    a die having a die slot for releasing a layer of a silicone-containing material onto the backing, the die being adjustable for selectively increasing and decreasing a distance between the die slot and the backing; and    a vacuum apparatus for generating a vacuum in proximity to the backing and the die and on an upstream side of the die relative to a moving direction of the backing.