Patent ID: 8114248

Claim:
A method for replicating three dimensional microstructures from a master pattern of microstructures onto a continuous rolling substrate band of a flexible planar material having a width, an image surface, which was coated with curable coating liquid, and a reverse surface comprising the steps of: providing an apparatus comprising an image drum having said master pattern of microstructures on a peripheral surface, an idler roll, a nip roll positioned in proximate parallel relation to said image drum, a source of ultraviolet radiation; transferring the continuous rolling substrate band of flexible planar material around said idler roll; bringing the image surface of the flexible planar material to the peripheral surface of the image drum at an entry point; providing a puddle of curable coating liquid between and in contact with the image surface and the peripheral surface of the image drum at the location of the entry point; applying pressure to the reverse surface of the flexible planar material across the width thereof to penetrate the coating liquid between the image surface and the peripheral surface of the image drum into the microstructures of the peripheral surface of the image drum, wherein the pressure at the nip roll is p=(T/lr)=(T entry e −fθ lr), where p is the pressure, T is an actuation force, l is a length of the image drum, r is a radius of the image drum, and θ is a selected angle in the direction of motion to the image drum; substantially curing the coating liquid prior to the image surface reaching an exit point and retaining on the image surface an impression of the microstructures on the peripheral surface of the image drum; and separating the substantially cured coating liquid on the image surface of the flexible planar material from the peripheral surface of the image drum at the exit point.