| 摘要 |
<p>Conventionally, when a constriction portion of a cylindrical package of a film is sealed by fusing alone without using any metal clip, a sufficient strength cannot be achieved. Therefore, in the invention, after filling a cylindrical body with a liquid or the like, a part of the content is removed, and a flat portion (Fr) is formed by pinching a portion of the body from the side opposed to a longitudinal seal portion (S1). When constricting forces P, P are applied to the flat portion (Fr) from both sides, the flat portion (Fr) is regularly folded, and the longitudinal seal portion (S1) is positioned at the center of the constriction portion and sandwiched by the film in the lateral direction. When the constriction portion is pressed by the longitudinal seal portion and a press surface parallel to the longitudinal seal portion, and fused by ultrasonic waves, a seal portion the film of which is uniformly pressed is formed. As a result, defective seal due to, e.g., a pin-hole or breakage hardly occurs.</p> |
