Patent Number: 6,254,969

Title: Shelf life indicator

Abstract: A shelf life indicating structure including a substrate printed with an oxygen sensitive ink in combination with an oxygen scavenging layer is disclosed. The oxygen scavenging layer prevents oxygen reaching the substrate for a predetermined interval. Once the finite oxygen scavenging capability of the layer is exhausted, oxygen reaches the substrate, thereby activating a visible indication such as a color change, in the ink. The substrate and layer may be formed into a patch or label for a package, and covered with an oxygen impermeable layer, such as a strip of aluminum foil which can be peeled off to initiate a shelf life indication structure. A method associated with the shelf life indicating structure is also provided.

Inventors: Eberle; Theodore F. (Chicago, IL)

Assignee: Crown Cork & Seal Technologies Corporation

International Classification: G01N 31/22 (20060101); B32B 027/14 (); B32B 003/00 ()

Expiration Date: 07/03/2018