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TGM determines the Long-Term Creep Behavior of Polyethylene Materials with the Kappa Multistation

The Department of Plastics Technology and Environmental Engineering at the TGM Federal Institute of Technology tests the temperature resistance and long-term material behavior of polyethylene for a number of applications, especially gas pipes and infiltration boxes (storm water boxes). The typical determination of long-term creep behavior used today involves an extremely tedious and costly process. With the time-saving Stepped Isothermal Method (SIM), TGM can simulate material behavior over a time span of more than 100 years, in a short period of time.

TGM is an independent federal test and inspection body in Vienna, Austria, divided into six departments. The Department of Plastics Technology and Environmental Engineering is the largest, focusing on testing of plastic pipe systems, disposal site components, the determination of burning behavior, as well as thermal analytics and structure analysis.

The Kappa Multistation from ZwickRoell in Fürstenfeld is implemented by TGM for the determination of the temperature-dependent creep modulus on various thermoplastics and their long-term creep behavior, as well as for review and confirmation of minimum requirements according to ÖVGW (Austrian Association for Gas and Water) and ÖNORM EN standards.

With tests only lasting a few days, TGM can use the SIM method to combine individual creep curves with step-by-step temperature increases to create a master curve over a long time period. This method requires quick changes and exact regulation of the temperature during testing. With the use of an automated and operator independent temperature controller and temperature chamber for temperatures from -10 °C to +100 °C, the precise specimen temperatures required for the SIM method are ensured.

The testing system has three individually controllable load axes with a maximum load of 10 kN, each of which is equipped with its own high resolution videoXtens for precise measurement of the specimen strain in accuracy class 1. Temperatures below room temperature are reached with an efficient air-cooled cooling unit.

The creep testing system used for the SIM-method allows TGM to optimally determine the long-term creep behavior of thermoplastics and supports engineers in the research institute with automated measured-value acquisition, simple evaluation options and reliable documentation through the well-proven testXpert testing software.