Method and apparatus for vacuum packaging with preshrinking
US4550548A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1983 |
| Grant date | Nov 5, 1985 |
| Priority date | — |
| Expiry date | May 26, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65B53/06
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A method for vacuum shrink packaging a product is provided that includes the steps of placing the product in a heat shrinkable thermoplastic bag; then shrinking the bag in a heated gaseous medium, while partially constricting the mouth of the bag to cause ballooning of the bag, further provided that the constricting is selected such that shrinkage of the bag overcomes the ballooning to collapse the bag onto the product; and then placing the bag in a vacuum chamber followed by vacuumizing and in-chamber sealing, further provided that the rate of vacuumizing is limited to substantially prevent reballooning of the bag. Associated apparatus for carrying out the method is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.