Tamper indicating device

Abstract

The invention is a tamper indicating device including a backing. The backing includes a first phase and a second phase. The backing is normally light transmissive, but a peeling force causes the backing to internally delamninate and become opaque. A first skin layer is fixed to the backing wherein the skin layer minimizes pre-destruction of the backing. A layer of adhesive is applied to the first skin layer, which can be affixed to a substrate.

1 . A tamper indicating device, comprising: 
 a backing including a first phase and a second phase, wherein the backing is light transmissive, and wherein a peeling force causes the backing to internally delaminate and become more opaque;    a first skin layer fixed to the backing wherein the skin layer minimizes pre-destruction of the backing; and    a layer of adhesive applied to the first skin layer.    
     
     
         2 . The tamper indicating device of  claim 1  wherein the first skin layer is comprised of the same material as the first phase.  
     
     
         3 . The tamper indicating device of  claim 1  wherein the backing contains about 75 percent of the first phase and about 25 percent of the second phase.  
     
     
         4 . The tamper indicating device of  claim 1  wherein the backing and first skin layer are formed using a co-extrusion blown film method.  
     
     
         5 . The tamper indicating device of  claim 1  wherein the first phase comprises a random copolymer of polypropylene and polyethylene.  
     
     
         6 . The tamper indicating device of  claim 1  wherein the skin layer comprises a random copolymer of polypropylene and polyethylene.  
     
     
         7 . The tamper indicating device of  claim 6  wherein the skin layer is less than or equal to about 0.00078 inches (0.0198 mm) in thickness.  
     
     
         8 . The tamper indicating device of  claim 5  wherein the skin layer comprises a low density polyethylene.  
     
     
         9 . The tamper indicating device of  claim 8  wherein the skin layer is about 0.0004 inches (0.010 mm) in thickness.  
     
     
         10 . The tamper indicating device of  claim 1  further comprising: 
 an initially viewable indicator that becomes obscured upon internal delamination of the backing.  
 
     
     
         11 . The tamper indicating device of  claim 1  further comprising: 
 a latent indicator that becomes viewable upon internal delamination of the backing.  
 
     
     
         12 . The tamper indicating device of  claim 1  wherein the backing includes a first backing surface and a second backing surface, and the first skin layer is fixed to the first backing surface and further comprising: 
 a second skin layer fixed to the second backing surface.  
 
     
     
         13 . The tamper indicating device of  claim 1  further comprising: 
 an overlaminate layer on the backing opposite the adhesive layer.  
 
     
     
         14 . The tamper indicating device of  claim 1  wherein the first skin layer is comprised of an adhesive.  
     
     
         15 . The tamper indicating device of  claim 1 , wherein the first skin layer having a modulus of firmness (G′) of between approximately 62169 Pascals and 291163 Pascals at 77° F. (25° C.).  
     
     
         16 . The tamper indicating device of  claim 1  and further comprising: 
 an article, wherein the adhesive is fixed to a surface of the article.  
 
     
     
         17 . The tamper indicating device of  claim 1 , wherein the skin layer includes pigment.  
     
     
         18 . A method for forming a tamper indicating device comprising: 
 co-extruding a blown-film backing and a skin layer wherein the backing includes a first continuous phase and a second discontinuous phase wherein the backing is normally light transmissive and becomes opaque upon internal delamination; and    applying a pressure sensitive adhesive to the skin layer opposite the backing.    
     
     
         19 . The method of  claim 18  wherein the co-extruding step comprises: 
 co-extruding the backing and skin layer from a die in a manner which inhibits the buildup of material on a lip of the die.  
 
     
     
         20 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer and the first continuous phase from the same material.  
 
     
     
         21 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer from a random copolymer of polypropylene and polyethylene.  
 
     
     
         22 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer to a thickness less than or equal to about 0.00078 inches (0.0198 mm).  
 
     
     
         23 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer to a thickness of about 0.0004 inches (0.010 mm).  
 
     
     
         24 . The method of  claim 18  further comprising: 
 applying an overlaminate layer on the backing opposite the skin layer.  
 
     
     
         25 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer from an adhesive material.  
 
     
     
         26 . The method of  claim 18  wherein the co-extruding step further comprises: 
 forming the skin layer from an adhesive having a modulus of firmness (G′) of between approximately 62169 Pascals and 291163 Pascals at 77° F. (25° C.).  
 
     
     
         27 . The method of  claim 18  further comprising: 
 attaching an article to the pressure sensitive adhesive opposite the skin layer.  
 
     
     
         28 . The method of  claim 18  further comprising: 
 adding pigment to the skin layer.