Method of making rectangular paperboard package
US5250018A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Nov 18, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D5/065
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A liquid tight rectangular paperboard container (10) is provided with a separate opening tab (17) secured to the top panel (15) thereof which enables the package to be opened to provide a fully open top. In particular, an elongate plastic window (18c) is formed along the front fold line (15a) connecting the top and front panels (15 and 11) of the package, and has ends (18d, 18e) connected to spaced apart arcuate shaped perforated lines (18a, 18b) extending to the rear corners of the top panel. In the construction of the package, the opening tab (17) is first ultrasonically welded to the outside surface of the package blank, and then the window section (18c) is pressed against and welded to the inside surface of the tab. A slit (40) which is formed in the window enables any air trapped between the window and the tab to escape during the welding operation. The package also includes a unique side sealing flap structure, while the particular paper supply roll from which the package is constructed has a unique structure. Also, a unique method of forming the package is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.