| 摘要 |
1298445 Seaming non-metallic sheet material DOW CHEMICAL CO 13 Jan 1970 [16 Jan 1969] 1639/70 Heading B5K [Also in Division B8] A chain 10 of bags has flaps 40, 42 interconnected by spot welds X to form a tube 48 which is passed along a mandrel 58 to a filling hopper 60. As each bag approaches the leading edge 62 of the hopper, the welds X rupture to allow the walls 28, 30 to pass on opposite sides of the hopper. After filling, each bag is longitudinally sealed between points 64 and 66 and the flaps 40, 42 are either removed or fabricated into handles. The welds X may be adhesive welds or may be heat welds which may be apertured if formed by hot needles e.g. a spiked wheel. Contaminants may be used to produce a weak weld. Lines of weakness 32 define adjacent bags which may be formed from polythene webs which may be tubular. |
