Tamper-evident fusion bonded pull-tab induction foil lining system for container closures
US5197618A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1991 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | Oct 15, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D2577/205
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A tamper-evident multiple layer induction foil liner for sealing the opening of a container comprises a "sandwich" having a first layer in the form of a fusion-bond heat seal polymer. This heat seal polymer is fusion bonded to the lip of the container opening to secure the liner to the opening. The next layer is a low-cohesive strength layer which, in turn, is bonded to an aluminum foil layer strengthed with tear-resistant backing. A pull-tab is provided to facilitate removal of the liner after the cap is removed from the container. When the pull-tab is lifted, the low-cohesive strength layer splits or shears through the application of a relatively small amount of force. Thus, the aluminum foil and tear-resistant backing readily may be removed from the container opening. It is then a simple matter to puncture the thin and mechanically weak polymer layer to uncover the container opening. A residue of the fusion bonded polymer, with a surface covering of a portion of the sheared low-cohesive strength layer, provides a readily observable tamper-evident residue on the lip of the container opening after the liner has been removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.