Easily openable tightly sealed bag
US4919272A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1988 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | Oct 12, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention provides an easily openable tightly sealed plastic bag which is formed of a film containing at least a substrate layer and a heat seal layer and is possessed of a sealed part whose substrate layer contains a multiplicity of through cuts, these cuts being formed substantially on the edge lines and partly or wholly closed with the heat seal layer. This tightly sealed bag safely retains the practical strength normally expected of any bag and avoids accidentally sustaining rupture while the bag is being transported or handled and yet permits itself to be opened with the force of finger tips. This invention manifests its utility particularly in a tightly sealed bag which is formed of a substrate of high strength and high barrier property. This invention further provides a method suitable for the production of the tightly sealed bag described above and a device to be used in working the method. The easily openable tightly sealed plastic bag of particularly desirable quality can be obtained by the method and the device so provided by this invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.