| 摘要 |
<p>PURPOSE:To surely and strongly seal both the ends of a lay-flat tube and leak no liquid at all by a method wherein projected parts are formed on the tube sealing face of a top force and/or of a bottom force. CONSTITUTION:A production mold 1 consists of a top force 2, on the tube sealing face 4 of which projected parts 5 are formed, and a bottom force 3. The height H of the projected part 5 is preferably formed to be 0.2t-0.4t, where (t) represents the thickness of a bag-like main body 12. A lay-flat tube 10 made of polyolefin-based synthetic resin is arranged between the top force 2 and the bottom force 3 so as to pinch the tube 10 under heat in order to melt and weld the tube 10. By being strongly pressed with the projected parts 5, primary welds 16 are produced through the compression of the constitutional material of the tube 10. Further, by being pressed with the tube sealing faces 4, secondary welds 17 are formed at the ends of the tube, resulting in realizing sure and strong sealed parts at both the ends of the tube.</p> |
