Benjamin Baudrit, Dietmar Kraft, Martin Bastian and Peter Heidemeyer
Posters # 2010 Vancouver
In 2008, the Sueddeutsche Kunststoff-Zentrum (SKZ), a testing and R&D plastics institute based in Wuerzburg (Germany), began in cooperation with the company WIDOS, a welding machine manufacturer based in Ditzingen (Germany), to develop a testing device for establishing the mechanical properties of joints executed by means of sleeve welding with an incorporated heating element (HM) and heated tool sleeve welding (HD) with mechanized torsional and linear shear tests. The aims of this investigation were to generate a reproducible test procedure for HM and HD welds and to investigate its utilization suitability. The core statement of this research paper is that the mechanized torsional shear test (MTS) and the mechanized linear shear test (MLS) are very suitable for detecting defects in HM and HD joints. In addition to frequent and, in part, obviously incorrect preparations (wrong insertion lengths of the pipe into the sleeve, etc.), it was possible to detect defects which, with the naked eye or with manual radial peeling and manual torsional shear tests, could not be recognized at all (like e.g. oil in the joining area, double welding, etc.) or only with very great difficulty or/and with great experience. (1, 2) Initial pioneering evaluation algorithms were generated in addition to the development and elaboration of the testing apparatus for the mechanized torsional shear test and the mechanized linear shear test. These two tests currently represent the best way to determine the short-term quality of HM and HD weldings. These two testing methods could revolutionize the plastic pipe industry branch regarding developing, testing, improving and supervising products.
