| 摘要 |
The present invention relates to an arrangement and a method of producing a continuous edge thickening (18) along a running direction of a web (2) of a positively and continuously transported thermoplastic film material. The web material (2) is folded through 180° along its outer edge region running in the running direction. After such folding, said web is, for the fixing of each respective fold, displaced an angle around a roller. Each respective folded area is passed through a welding device in order to provide a unifying weld between the fold/folds and the remainder of the web. By utilising the residual heat stored in the fused and welded material, each folded and welded edge of the web, in its tensioned state, is moved around rollers (9, 11), with progressively reducing available roller width. With ramp formations at respective outer edge, the folded and welded edge is deformed to a loop. |
