| 摘要 |
<P>PROBLEM TO BE SOLVED: To manufacture an inner bag for a transportation tank which is free from a concern of forming a pinhole. <P>SOLUTION: A cylindrical film 23 is pulled out of a film roll 24 and is cut into a piece of a prescribed length IL. An inner bag supply/discharge port attaching hole 27 is formed on the cut cylindrical film 23, and an inner bag supply/discharge port is welded to the attaching hole 27 by heat. One end 23a of the cylindrical film 23 is welded together by ultrasonic wave using an ultrasonic welding device, and the other end 23b of the film 23 is also welded by ultrasonic wave after the film 23 is deaerated. Then, an inner bag body made out of the film 23 is folded after a positioning mark is put on the inner bag body, and is put in a packaging bag. The above manufacturing processes are executed in a work chamber 17 in which clean air 19 flows down from a duct 18. In these processes, attachment of dust, such as iron powder, to the inner bag is prevented, thus the concern of forming a pinhole is eliminated. Hence, there is no need to give the inner bag body 23 a double structure so that the weight of the inner bag body 23 can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
