End sealing device for a plastic film in a packaging apparatus
US4288968A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 3, 1979 |
| Grant date | Sep 15, 1981 |
| Priority date | — |
| Expiry date | Dec 3, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/919
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A heat sealing device in a packaging apparatus utilizing a plastic film for continuously seal both ends of a plurality of cylindrical bags made from the plastic film. The device comprises a pair of heat sealing members provided separatably and oppositely against each end portion of each cylindrical bag which is to be sealed transversely across the film. Each heat sealing member has a heat sealing surface which is to be pressed against the film and at least a pair of sealed chambers inside the heat sealing surface containing working liquid as a heat medium. A heat source is provided to heat at least a portion of the sealed chamber so that the working liquid generates vaporized gas by the heat. The sealed chamber is controlled to be kept at a pressure and a temperature so that the vaporized gas is condensed substantially at a temperature under which the film is sealed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.