Patent ID: 6120710
Filing Date: 2000-09-19
Classification: B44F,D06C,D06Q,G03H,Y10T

Abstract:
A process for making a fibrous sheet that produces rainbow or hologram images, comprising the steps ofpreparing a sheet of fibrous elements;softening at least the fibrous elements on a surface of the sheet;placing the sheet on a supporting surface;bringing a hard embosser having a surface with a pattern of fine grooves thereon into direct contact with the surface of the fibrous sheet having the softened fibrous elements, the grooves being spaced apart uniformly by about 0.1 to 10 microns and being at least 0.01 microns deep;imposing sufficient load on the embosser for a sufficient time to impress the pattern of fine grooves into the surface of the softened fibrous elements on the surface of the sheet with negligible bonding of fibrous element cross-over points, the patterns of fine grooves on the individual fibrous elements of the sheet surface continuing to neighboring fibrous elements substantially in phase, with the distance between the last groove on one fibrous element and the first groove of the neighboring fibrous element being a multiple of groove width;separating the sheet from the embosser; andcollecting the separated sheet.