Tamper indicating security bag

Abstract

A method of manufacturing tamper indicating security bags (e.g. for the transportation of case) from plastic film. The method comprises (a) forming an elongate rectangular strip of plastics film material; and (b) folding the opposed long edges of the strip towards the centre to form a pair of flaps with a gap between their inside edges, which leaves the central area of the strip exposed; or the method comprises (a) forming an elongate flattened tube of plastics film material (b) cutting the tube longitudinally to form a pair of flaps in the overlying material of the flattened tube; and (c) exposing a central area of the underlying material in a gap between the air of flaps. In either case the method also includes (i) selectively applying layers of adhesive and ink, adapted to form a tamper-evident sealing means, to the central area; (ii) slitting the strip down the middle of the central area to form a pair of elongate folded strips; and (iii) cutting the folded strips transversely at equal intervals, to form individual folded sections of material which can be turned into bags for example by heat sealing the cut edges.

1 - 9 . (canceled) 
     
     
         10 . A tamper evident security bag comprising:
 a mouth;   an integral closure lip; and   a tamper evident feature on the closure lip, the tamper evident feature comprising:
 a patterned release layer, 
 a coating ink layer applied over the release layer, 
 a thermochromic ink applied in a region away from the release layer and the coating ink layer, and 
 an adhesive, 
   wherein the adhesive is applied to the closure lip covering the tamper evident feature and in a region under the mouth of the bag which faces a side of the bag opposite the closure lip.   
     
     
         11 . A tamper evident bag according to  claim 10 , wherein the patterned release layer is formed by a first layer of ink applied in a pattern directly onto the closure lip prior to corona treatment. 
     
     
         12 . A tamper evident bag according to  claim 10 , further comprising a mask of text i applied to a region of the release layer to mask any shadow of a release pattern formed by the patterned release layer. 
     
     
         13 . A tamper evident security bag according to  claim 10 , further comprising a second layer of coating ink to improve opacity of the coating ink covering the patterned release layer and to thicken the coating ink layer, so that a more significant air gap is produced when tampering occurs which leaves some ink attached to the closure lip and some of the ink coating the patterned release layer adhered to an opposing surface of the closure lip. 
     
     
         14 . A tamper evident security bag according to  claim 10 , further comprising a release liner, applied over the adhesive. 
     
     
         15 - 17 . (canceled)