| 摘要 |
A process for producing a tubular casing by folding a flat plastic sheet (1) into a tubular structure by a shaping former (6) as the sheet advances, and joining the meeting edges of the folded sheet to form the tubular casing, characterized by forming grooves (13) on one or both sides of the sheet along fold lines, coating a surfactant (12) on the sheet surface at least at the fold line portions of the sheet surface which are to be brought into contact with the shaping former, and then folding the sheet into a tubular structure by the shaping former. |
