| 摘要 |
<P>PROBLEM TO BE SOLVED: To heat seal the mouth of a flexible packaging bag made of plastic or the like to form a kerf on the mouth simultaneously. <P>SOLUTION: A sealing device comprises a sealing block 11 to which a rubber cushioning material 10 is attached and a sealing bar 13 on the lower face of which an iron tape filament 12 is arranged longitudinally, and welds a bag mouth 15 by heating it with impulse currents from the filament 12. Two thin grooves 19, each of which is 1-1.5mm wide, are formed in an area, where the filament 12 is arranged, on the upper face of the cushioning material 10, with an acute angle ridge 20 formed between the thin grooves 19. When the sealing bar 13 approaches the sealing block 11 to sandwich the bag mouth 15 in-between and the impulse currents applied to the tape filament 12 generate heat, the filament 12 heat seals the bag mouth 15 at a contact surface other than the thin grooves 19. At this time, heat concentration is intensive at a part of the bag mouth 15 in contact with the acute angle ridge 20, which makes both sides of the acute angle ridge 20 brittle, thus tearing the bag near the acute angle 20 becomes possible. <P>COPYRIGHT: (C)2004,JPO |
