| 摘要 |
In a vacuum-sealing method and apparatus for various articles to be packed under vacuum, the improvement consisting in that a hot-air circulating closed-loop path is provided within the vacuum-packaging enclosure, so as to have hot air circulating unidirectionally in order to sweep the package virtually concurrently with the evacuation and autogenous welding stage. A swingable flap valve inserted in the hot-air path upstream of the specially provided heating means ensures such a unidirectional hot air flow. By so doing, the vacuum-packing operations can be more efficiently and quickly completed. The package wrappers are made of a thermoplastics, heat-shrinkable material. |
