Time-temperature integrating indicator device with barrier material

摘要

A time-temperature indicator device provides a visually observable indication of the cumulative thermal exposure of an object. The device includes a substrate having a diffusely light-reflective porous matrix and a backing. The backing includes on its surface a viscoelastic indicator material for contacting the substrate and a barrier material for substantially inhibiting the lateral flow of viscoelastic indicator material between the substrate and the backing.