Method and apparatus for the manufacture of plastic bags in pairs with side seams
US4906228A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Apr 1, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S493/926
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a process and apparatus for the paired manufacture of carry bags from synthetic resin sheeting with lateral weld seams and an approximately sinusoidal load-bearing rim with punched-in handle openings, wherein a laid-flat tubular film is cut open in wave shape, and the two cut-apart semitubular sheets (1a, 1b) are pulled apart transversely to the conveying direction, the wave crests are folded over at least in part in parallel to the folding edges (3) in each case either toward the outside or toward the inside, then the semitubular sheets are again united in order to compensate for at least a portion of the gap S produced by folding over the flaps, and after achieving a synchronous run of the folded over flaps (51, 52), the latter are welded to the lower and upper sheet layers (10a, 10b) of the semitubular sheets (1a, 1b) in the area (15) surrounding the subsequent handle opening (4), the wave crests, prior to being folded over, being electrically discharged and, after having been folded over, being again charged electrically prior to the provision of the weld bond.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.