Plastic bags with releasable closure which resists opening from inside
US4561109A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1984 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | Jun 22, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24008
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A flexible bag has a releasable closure with a fin extending away from one of the mating pluralities of hook-like protrusions. The fin is joined to the base of the hook-like protrusions to apply disengaging force for opening the closure from the outside of the bag. The closure resists opening force from inside the bag. The protrusions have hook-like ends which have the same shape on all protrusions, which extend in one direction on one of the plurality of protrusions and in the other direction on the other plurality of protrusions. The protrusions are easily extruded from molten thermoplastic and applied to a moving web of film during an in-line bag manufacturing process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.