| 摘要 |
1,076,009. Seaming gussetted plastics tubing. COMPAGNIE INDUSTRIELLE DES TEXTILES ET EMBALLAGES PLASTIQUES C.I.T.E.P. Jan. 13, 1966 [Dec. 1, 1965], No. 1740/66. Headings B5D and B5K. Transverse welds are made in gussetted tubing in two stages: in one the gusset region is heated at (3) (Fig. 1, not shown), in the other the tubing is heated throughout its width by a welding member (4). The welding members (3), (4) may be spaced along the path of a moving web, and the welding member (4) may incorporate a knife (7) (Fig. 3, not shown). The welding member (4) may be controlled so that it makes either a single transverse weld, to produce open-ended bags, or a pair of spaced welds to produce closed bags. The welding members may be heated by a circulating fluid or by continuous or pulse electric heating. The tubing may be extruded or folded and longitudinally welded. The jaws 3 may be replaced by means blowing hot air into the gusset or by heated plates kept in contact with the material and heated either continuously or in pulses. |
