Plastic film heat seal apparatus
US6739367B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 2002 |
| Grant date | May 25, 2004 |
| Priority date | — |
| Expiry date | Oct 30, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/1122
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a plastic film heat seal apparatus which comprises a heat seal bar covered with at least one low adhesive sheet. The heat seal bar is pressed against superposed layers of plastic film so that the layers of plastic film can be heat sealed with each other by the heat seal bar to have a heat sealed portion whenever the layers of plastic film are intermittently fed in a direction and temporarily stopped. The low adhesive sheet is interposed between the heat seal bar and the layers of plastic film for protection of the layers of plastic film when the heat seal bar is pressed against the layers of plastic film. The heat seal bar is then retreated and spaced from the layers of plastic film to permit the layers of plastic film to be fed again after being heat sealed. The heat sealed portion includes upstream and downstream edges in the plastic film feeding direction. The apparatus further comprises loosening means by which the low adhesive sheet is loosened at a position upstream of the heat seal bar in the plastic film feeding direction after the heat seal bar is pressed against the layers of plastic film. The apparatus further comprises holding means by which the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.