Method of cutting and sealing film
US6282869A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1998 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Jul 20, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/108
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In the packaging of a wide variety of products in flexible film bags, problems with edge tear and incomplete bag cut-off have been encountered. The edge tear and incomplete cut-off are worse for films containing low melting polymers, such as metallocene-catalyzed ethylene/alpha-olefin copolymers. These problems can be solved using a clamp-cut-seal process, as opposed to a clamp-seal-cut process. By cutting before sealing, the film is still cool, and the strain on the film due to the cutting does not pull on the seal area enough to cause edge tearing (i.e., tearing at the seal). The higher resistance to elongation of the cool, clamped film also serves to reduce or prevent incomplete bag tail cutoff. Also, by providing a means for sealing which clamps the film before it is cut, defective seals from bag "pull back" can be avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.