Retroreflective cube corner sheeting mold and method for making the same

Abstract

A method is disclosed for manufacturing a plurality of laminae for use in a mold suitable for use in forming retroreflective cube corner articles. Each lamina has opposing first and second major surfaces defining therebetween a first reference plane. Each lamina further includes a working surface connecting the first and second major surfaces. The working surface defines a second reference plane substantially parallel to the working surface and perpendicular to the first reference plane and a third reference plane perpendicular to the first reference plane and the second reference plane. The method includes orienting a plurality of laminae to have their respective first reference planes parallel to each other and disposed at a first angle relative to a fixed reference axis. At least two groove sets are formed in the working surface. Each groove set includes at least two parallel adjacent V-shaped grooves in the working surface of the laminae. The at least two groove sets form first, second and third groove surfaces that intersect substantially orthogonally to form a plurality of cube corner elements. Each of the plurality of cube corner elements is preferably located on essentially one of the plurality of lamina. The plurality of laminae can be oriented at a second angle relative to the fixed reference axis prior to forming at least one of the groove sets. A mold according to the present invention and a retroreflective article made therefrom are also disclosed.

What is claimed is:  
     
         1 . An article comprising an array of nonrulable cube corner elements, the article comprising a plurality of laminae, each such lamina having opposed parallel major surfaces and a working surface connecting the major surfaces, the array having rows of rectangular cube corner elements formed along the working surfaces of the laminae.  
     
     
         2 . An article comprising a plurality of laminae, each lamina having opposed parallel major surfaces and a working surface connecting the major surfaces, the working surface of each lamina having an inclined surface extending along the working surface and a set of parallel grooves defining groove surfaces orthogonal to each other and to the inclined surface so as to form a row of rectangular cube corner elements.  
     
     
         3 . A lamina having opposed parallel major surfaces and a working surface therebetween, the working surface having an inclined surface extending therealong and a set of parallel grooves defining groove surfaces orthogonal to each other and to the inclined surface so as to form a row of rectangular cube corner elements.  
     
     
         4 . A plurality of laminae as set forth in    claim 3   , the plurality of laminae defining in the working surfaces thereof a nonrulable array of cube corner elements.