| 摘要 |
1,024,009. Making thermoplastic bags on mandrels. F. R. HESSER MASCHINENFABRIK A.G. Jan. 20, 1965 [Feb. 18, 1964], No. 2403/65. Heading B5D. After a thermoplastic bag blank has been folded into tubular form on an auxiliary mandrel 1 (Fig 1) and sealed longitudinally by jaws 3, 4, it is carried by the jaws to an intermediate mandrel 6 which is rotated about its axis to re-orientate the partially formed bag prior to its transfer to a shaping mandrel 9. In the form shown a folding box 2 is raised so that the sides of the box blank are folded about the mandrel. A guide bar, which is raised before the longitudinal seam is formed, may form a guide for lining up the edges of the sheet correctly. Alternatively, compressed air may be blown through orifices in the top of the mandrel 1. A shaft 5 (Fig. 1) carrying the jaws 3, 4, is then moved towards the intermediate mandrel 6 which is preferably tapered to facilitate drawing the tube over the mandrel. The mandrel 6 is then rotated through 90 degrees so that, when the tubular blank is drawn by grippers 7 on to the shaping mandrel 9, the longitudinal seam lies along one of the side edges of the mandrel. The shaping mandrels 9, which preferably comprise two parts 38, 39 which can be moved together as the bag is drawn on to the mandrel, are carried on an intermittently rotating wheel 8. |
