| 摘要 |
<p>Machinery for spreading an advancing tubular shrink-wrap film comprises a floating mandrel supported vertically within descending tubular film by external rolls which bear through the film against rollers located on the mandrel is a waisted section. Alignment of the mandrel with the film axis is maintained by ancillary rolls which bear, via the film, against the mandrel surface above and below the level of the supporting rolls. The flat film is parted by a trapezoidal wedge carried on the top of the mandrel. The lower half of the mandrel incoporates a piston which can extend a cap to align the item to be wrapped exactly on the joint film and mandrel axis. The support rollers are driven intermittently to advance successive portions of the film for wrapping a sequence of items. For applying successive portions of e.g. shrink wrap PVC film to a series of items passing beneath the mandrel position. Simpler and cheaper than prior art equipment involving electromechanical alignement devices and/or vacuum or conveyor clamp film advance systems.</p> |
