US Patent:
20030230379, Dec 18, 2003
Inventors:
Marc Roubik - Glendale AZ, US
International Classification:
B32B031/00
US Classification:
156/229000, 156/163000, 428/212000
Abstract:
A two-sided lamination process controlling curl caused by memory in laminate material, such as polyester, polypropylene, or nylon. The method involves matching or aligning the grain orientation of a top laminate sheet or film with the grain orientation of a bottom laminate sheet or film. The method includes selecting laminating films from the same position on the stretched or oriented web for the top and bottom laminating films. To achieve opposing forces, opposite sides of the web from a particular web position are coated with thermally activated adhesive to form the top and bottom laminating materials or supply rolls. Rolls of the two types of laminating material are then fed concurrently to a laminator to coat opposite sides of a substrate with laminate films with grain orientation or memory that creates substantially equal bending forces but in opposite directions.