Draw tape bag and method of manufacture
US6561696B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1997 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Apr 15, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D33/28
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A plastic draw tape bag includes a non-destructive hem seal which runs along the width of the bag to secure the draw tape. The seal is created by bonding two layers of film by using an adhesive, a hot seal, or a coextruded film. When stressed by adequate forces, the seal will partially open without tearing the film. However, it will open only to the extent that the load exceeds the seal strength. Once the film absorbs the load and the stress is relieved, the seal will stop opening and the remaining portion of the seal will remain intact. Thus, the stress concentration is dissipated without tearing the film at or near the seal. As a result, the bag will fail only when the forces on the bag exceed the load bearing limit of the film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.