| 摘要 |
897,321. Paper bags etc; packaging machines. KLEIN, E. Sept. 10, 1958 [Sept. 24, 1957; Feb. 22, 1958], No. 29072/58. Classes 94(1) and 94(2). A paper bag 1 comprises a valve passage 6 to receive a feed pipe 4 and having thermoplastic composition 3 for sealing the vent which is outside the inner face 8 of an insert 7, Fig. 1, which contacts the feed pipe. On heating the composition 3 and withdrawal of the free end of the insert 7, Fig. 2, it is split lengthwise of the passage 6 so that the composition is exposed and can seal the bag. Numerous modifications are described employing tongue-shaped or tubular inserts but in all cases the insert prevents direct contact of the thermoplastic composition with the feed pipe. In one modification, Fig 12, an additional double fold 36, 37 is provided which when the insert 42 is withdrawn serves to move the dust 45 left by the filling material out of reach of the thermoplastic composition 3. Additional thermoplastic composition 3a may be provided in the region of the double fold 36, 37. Specification 897,322 is referred to. |
