| 摘要 |
944,070. Seaming non-metallic sheet material. ST. REGIS PAPER CO. Nov. 17, 1961 [Dec. 29, 1960], No. 41211/61. Heading B5K. [Also in Division B8] The folded-over ends 12 of a thermoplastic film, e.g. polyethylene or polypropylene, wrapped around a loaf of bread 11 are heat sealed to each other and are simultaneously sealed to a paper label 13, coated with thermoplastic adhesive and placed thereover, by a heated gas blown against the outer surface of the label. The labels 13 are severed from a roll by a knife 14 and applied to the ends 12, which may be slightly preheated, by pushers 15 which may be heated. Each loaf 11 is fed by a pusher 16 carried on a continuously moving overhead endless chain between freely movable, endless belts 17, having heaters 18 between the runs thereof, to compress the ends slightly. The pusher 16 is elevated to leave the loaf 11 at a section B at which heated fingers 20 seal the bottom overlap of the wrapper and heated air supplied through conduits 24 having nozzles 25 opening between rollers 22, 23, 26 seals the label 13 to the ends 12. After one second the loaf is pushed by an oncoming loaf between compression belts 29 having heaters 31 between the runs thereof and passing around rollers 26, 30 which may have heaters therein, and passes on to a moving belt 21. An endless belt 27 passing around rollers 22, 28 protects the upper part of the wrapper ends from deflected hot air. The belts 17, 27, 29 and the vertical rollers are composed of or surfaced with polytetrafluoroethylene-covered fibreglass. In a modification, Fig. 8 (not shown), the belt 27 is replaced by a polytetrafluoroethylene - covered metal tube through which cooling water is circulated. |
