Heat treatment of thin polymer films

Abstract

Stretch film is treated by passing a web of tackifier-containing, unbloomed thin polymer film through a heater so that the web is heated to a temperature sufficient to cause tackifier bloom prior to the web reaching a next stage in an in-line process. Also, a pattern can be applied to a thin polymer film. An oriented web of thin polymer film is passed across at least one heated roller having the pattern engraved thereon to define face regions and relief regions collectively conforming to the pattern. As the web contacts each roller surface, portions of the web positioned over the relief regions receive less heat than portions of the web positioned over the face regions, thereby causing the respective portions of the web to undergo differential, heat-induced shrinkage which imparts the pattern to the thin polymer film.

1 .- 7 . (canceled) 
     
     
         8 . A thin polymer film carrying a pattern defined by at least one first region that has undergone greater heat induced shrinkage than at least one second region. 
     
     
         9 . The thin polymer film of  claim 8 , wherein:
 the thin polymer film contains tackifier;   the tackifier in the at least one first region is bloomed; and   the tackifier in the at least one second region is unbloomed.   
     
     
         10 .- 18 . (canceled)