| 摘要 |
<p>The system consists of four warm air supply units, one on each side of the framework which surrounds the package whose packaging film is to be contracted. Each air supply unit consists of an electric motor driving a fan which blows air over electric heating elements and through a narrow horizontal slot. Some of the heated air is recirculated by being drawn in through additional slots positioned on either side of the exit slot. The hot air heats the pockets of air trapped inside the film causing it to expand and push the film away from the package and so facilitates removal of the film.</p> |
