Method of forming a tamper resistant envelope closure
US5641318A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1995 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Apr 28, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D33/20
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A method for forming a tamper-resistant envelope formed of a thermoplastic resin comprises two opposing panels having respective bottom and side wall edges bonded together to form a pocket therebetween. The top of the pocket is open for inserting an item into the pocket. Each panel has an edge portion adjacent the opening. A bead of pressure-sensitive adhesive is applied adjacent the edge portions, and the bead is heat-seal bonded to the thermoplastic edge portion. The edge portions can be brought together to bring the adhesive beads into contact to close the opening. By heat-seal bonding the adhesive beads to the thermoplastic edge portions, the pressure-sensitive adhesive is less susceptible to being opened by supercooling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.