Tamper-evident structures
US5149386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1990 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Dec 17, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/915
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
The invention relates to a laminated tamper-evident structure which exhibits an irreversible color change upon delamination. The structure includes a laminate of at least two layers capable of generating a color by a light interference and absorption phenomenon that requires direct and intimate contact between an adjacent two of the layers. The strength of attachment among the layers of the laminate is such that the laminate can be uniformly and reliably peeled apart at the interface between the adjacent two layers. An overlying flexible strip of transparent or translucent material is adhered to the laminate to facilitate the peeling operation. Upon peeling apart the laminate, the generated color is irreversibly lost, thus providing evidence that the structure has been tampered with. The structure can be incorporated into a variety of closable articles or products to provide evidence of opening or tampering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.