| 摘要 |
822,202. Seaming non - metallic sheet materials. BRITISH CELLOPHANE Ltd. Jan. 16, 1958 [Jan. 17, 1957], No. 1817/57. Class 42 (1). A process for the manufacture of large folded sheets of thin flexible material from flattened tubing 14 comprises bringing the tubes together to form a multi-ply assembly, bonding (at 10, 11) the tubes together at a selected longitudinal edge of the assembly and cutting off the edge portion (as shown in Fig. 4) either before or after bonding. The edge portion may be cut off by trimming through the bonds 10, 11. As shown in Fig. 2, three polythene tubes 1, 2, 3 are bonded together by means of two streams 7 of molten polythene from jets 8 as the tubes pass between rollers 4, 5 which may be heated or cooled, the assembly of tubes being drawn past cutter blades 12, 13 which cut off the edge portion of the assembly. |
