摘要 |
This apparatus has an anvil (23) supporting seal fins (21), a horn (35) consisting of a cylindrical portion and a forwardly convergent portion (35b), and a means for pressing the seal fins (21) against the anvil (23) via the front end of the horn (35) and transmitting ultrasonic vibration to the seal fins (21). The horn (35) is adapted to transmit ultrasonic vibration to a packaging material, fuse the sealant layers of the seal fins (21) to each other and seal the packaging material. An ultrasonic vibration absorption means is provided between the front end of the horn (35) and edge portions (25) of the seal fins (21) and adapted to absorb ultrasonic vibration. The seal fins (21) are excited when they receive ultrasonic vibration, and the ultrasonic vibration advancing toward the edge portions (25) is absorbed in the ultrasonic vibration absorption means, so that the ultrasonic vibration is not transmitted to the edge portions (25). Accordingly, dust does not occur in the end surfaces of paper substrates exposed at the edge portions (25) of the seal fins (21). <IMAGE> |