Film tension compensation device for bag making machine
US4959044A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1989 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | Apr 7, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB31B2160/10
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A bag making machine and method for the continuous production of bags from a folded web of thermoplastic material is provided. The apparatus includes a capability for making bags of differing widths as well as making bags having consistent widths for the particular size of bag selected. The apparatus includes a rotatable drum having a plurality of sever and seal stations for forming individual positioned about the outer periphery of the drum. A source of a continuous folded web of thermoplastic material is also provided, and continuously fed onto the surface of the drum. Means positioned between adjacent sever and seal stations tuck the web of material inwardly from the periphery of the drum. To prevent the occurrence of stretching forces which may adversely affect the web and the resulting width of the bags during processing, a film tension compensation means is provided for maintaining a constant path length for the web of material between the web source and the sever and seal stations. This results in the maintenance of a substantially constant tension on the web.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.