| 摘要 |
To form a continuous length of flexible sheet material from which a tubular product may be produced a plurality of individual lengths (L1, L2) are secured together end to end. Adjacent ends of adjacent lengths are cut at an angle other than 90 DEG , preferably 30-60 DEG , more preferably 45 DEG , to the lengthwise dimension such that when the tube is formed a spiral-shaped joint is formed. The joint (J1, J2) may be stitched, bonded or welded, the latter being preferred where the sheet material is e.g. a non-woven fabric with a backer layer laminated to one side; in such case a strip of the same material as the backer may be applied to the lengthwise edges of the backer and be welded to it. |
