Welding extrusion fillet

Fig. 9.12b. This photograph shows that the anchoring technique provides complete flatness even in critical areas (slope toe and pipe penetration constractions). In such places where hand-welded extrusion fillet seams occur in higher frequency and standing leachate can be expected, special care and high technical installation skills are required. Only experienced, particularly qualified and well-equipped specialist installation companies can master this task. Courtesy Schicketanz Consulting Engineers, Aachen...

In extrusion fillet welding of geomembranes a melt strand (extmdate) of the same or very similar HOPE resin material as the geomembrane is ap-... 

Extrusion welding produces a so-called extrusion fillet seam. Figure 10.5 shows the seam shape. Certain geometrical conditions are required of this seam shape as well. Figure 10.5 shows the dimensions of the extrusion fillet seam in accordance with DVS 2225-4 for minimiun 2.5 mm thick HDPE geomembranes used in Germany for lining landfills and contaminated land. In addition to the actual dimensions, the so-called factor of seam thickness fsA is used to assess seam quality ... 

In the long-term tensile test on tensile test bars with dual hot wedge seams and extrusion fillet seams the plane of the seam is not perpendicular to the tensile direction, as in butt welded pipe seams, but parallel. The force flow in the loaded specimen is directed over the weld seam from one geomembrane into the other in an offset direction, therefore force flow lines get more dense in the boundary region of the weld seam and a stress concentration develops. In the boundary region there are also noteh effects induced by the transition from the welded material area to the base material. A eraek that develops there... 

Struve F (1990) Extrusion Fillet Welding of Geomembranes. Goetextiles and Geomembranes 9 281-293... 

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