Reinforced thin wall plastic bag, and method and apparatus to make material for such bags
US4076121A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1976 |
| Grant date | Feb 28, 1978 |
| Priority date | — |
| Expiry date | Feb 17, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24694
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A plastic bag such as trash can liners, grass and leaf bags, sandwich bags and the like is reinforced by placing spaced ribs therein, integral with the wall structure, the ribs having a rib-to-rib spacing in the order of 1/8 to 2 cm, the ribs being peaked and merging smoothly from a projecting peak to the thickness of the walls between the ribs, the peaks extending about 1.5 to 10 times the wall thickness of the film which is preferably, in the order of about 0.4 to 2.0 mils. Upon extrusion, the extrusion die is formed with small notches with rounded corners so that the ribs are extruded while the film material is extruded, and provide additional material in the region of the ribs which merges smoothly with the material being extruded to form the film. Such rib-reinforced bag structures may be produced by forming a continuous roll of such bags, the individual bags in such a roll being readily separated along predetermined lines of weakness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.