Plastic bag construction
US4931033A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Feb 1, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S493/926
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of making plastic bags in an in-line production stream having hand holes reinforced by double ply plastic material in which the molecular orientation of the plastic material extends across the bags and generally parallel to the upper ends of the bags. The method includes forming a longitudinal gusset along the upper ends of the bags in the machine direction of the plastic extrusion, slitting the inner fold line of the gusset, sealing the inner slit ends longitudinally to the adjacent front and back walls of the bags, forming transverse seals to close the side edges of the bags and separating the bags along the transverse seals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.