Formation of retroreflective sheeting with controlled cap-y

Abstract

A retroreflective laminate sheeting has a viewing surface having a retroreflective layer which has a first cap-Y value of a viewing surface side thereof. A plurality of discrete pigmented indicia are disposed on the viewing surface side of the retroreflective layer. The pigmented indicia define a second cap-Y value of the viewing surface of the sheeting, the second cap-Y value being less than the first cap-Y value. One method of making a retroreflective sheeting includes forming a retroreflective layer on a web, the web moving in a web direction. The method includes applying a pigmented material proximate the retroreflective layer, the pigmented material preferably forming a plurality of parallel stripes oriented substantially in at least one of the web direction and a direction orthogonal to the web direction.

1 . A method of making a retroreflective sheeting having a viewing surface, comprising: 
 forming a retroreflective layer on a web, the retroreflective layer having a first cap-Y value on a viewing surface side thereof, the web moving in a web direction; and    applying a pigmented material proximate the retroreflective layer, the pigmented material forming a plurality of parallel stripes oriented substantially in at least one of the web direction and a direction orthogonal to the web direction;    wherein the pigmented material defines a second cap-Y value of the viewing surface of the sheeting, the second cap-Y value being less than the first cap-Y value.    
   
   
       2 . The method of  claim 1  wherein the step of applying the pigmented material includes applying the pigmented material to an overlay layer.  
   
   
       3 . The method of  claim 2  further comprising laminating the overlay layer to the retroreflective layer on the viewing surface side thereof.  
   
   
       4 . The method of  claim 3  wherein the pigmented material is sandwiched between the overlay layer and the retroreflective layer.  
   
   
       5 . The method of  claim 1  wherein the retroreflective layer is selected from cube corner-based sheeting and microsphere-based sheeting.  
   
   
       6 . The method of  claim 5  wherein the cube corner-based sheeting comprises a structured surface provided with a plurality of cube corner elements.  
   
   
       7 . The method of  claim 6  wherein the cube corner elements are bound by at least two intersecting sets of parallel grooves, and wherein the pigmented indicia are not substantially aligned with the grooves.  
   
   
       8 . The method of  claim 1 , wherein the stripes have a substantially uniform stripe width.  
   
   
       9 . The method of  claim 8 , wherein the stripe width is between about 0.1 mm (about 4 mils) and about 1.0 mm (about 39 mils).  
   
   
       10 . The method of  claim 1 , wherein the stripes have a distribution density of from about 2 to about 10 stripes per centimeter (about 5 to about 25 stripes per inch).  
   
   
       11 . The method of  claim 1 , wherein the stripes vary in width.  
   
   
       12 . The method of  claim 1 , wherein at least some of the stripes are not continuous.  
   
   
       13 . The method of  claim 1 , wherein the pigmented material is substantially gray.  
   
   
       14 . The method of  claim 1 , wherein the pigmented material is substantially black.  
   
   
       15 . The method of  claim 1 , wherein the pigmented material covers from about 10% to about 25% of the viewing surface side of the retroreflective layer.  
   
   
       16 . The method of  claim 1 , wherein the pigmented material comprises a plurality of sets of parallel stripes, and wherein the stripes of one set are offset from the stripes of an adjacent set.  
   
   
       17 . The method of  claim 1 , wherein the pigmented material comprises an opaque ink.  
   
   
       18 . The method of  claim 1 , further comprising: 
 applying a second pigmented material to an overlay layer, the second pigmented material transforming the overlay layer into a transparent color layer.    
   
   
       19 . A method of making a retroreflective sheeting having a viewing surface, comprising: 
 forming a cube corner-based retroreflective layer on a web, the retroreflective layer having a first cap-Y value on a viewing surface side thereof, the web moving in a web direction, wherein the layer comprises a structured surface provided with a plurality of cube corner elements, the cube corner elements being bounded by at least two intersecting sets of parallel grooves; and    applying a pigmented material proximate the retroreflective layer, wherein the pigmented material is not aligned with the grooves;    wherein the pigmented material defines a second cap-Y value of the viewing surface of the sheeting, the second cap-Y value being less than the first cap-Y value.    
   
   
       20 . A method of controlling a cap-Y value of a retroreflective sheeting having a viewing surface, comprising: 
 providing a retroreflective layer, the retroreflective layer having a first cap-Y value on a viewing surface side thereof; and    applying a pigmented material proximate the retroreflective layer;    wherein the pigmented material defines a second cap-Y value of the viewing surface of the sheeting, the second cap-Y value being less than the first cap-Y value.