50 Years of Continuous Testing of Pipes made from Hostalen HDPE Grades Completed
Dec 7, 2006
Pipes made from Basell's Hostalen high density polyethylene have now undergone 50 years of continuous testing, according to Ulrich Schulte, head of the Application and Technical Service for Basell's Pipe and Sheet business unit.
"Two pipe specimens made from Hostalen GM5010 that were installed in October 1956 are still in service and continue to undergo creep tests designed to evaluate the progressive deformation of the pipes under pressure at a temperature of 20 °C," Schulte said.
When HDPE pipe grades were in the early development stages at Basell predecessor company Hoechst, customers were aiming to produce water pipe systems with a minimum service life of 50 years, according to Schulte, who is based at Basell's PE research and development centre in Frankfurt, Germany.
"Creep tests by Hoechst on pipes made from Hostalen HDPE commenced in 1954," Schulte said. "In the early years of plastic pipe material development the researchers at Hoechst were basing their indication of service life on accelerated pressure tests at elevated temperatures, and the results were then extrapolated using a mathematical formula, the Arrhenius methodology." In 1956 long term creep testing at room temperature (20°C), was also initiated.
Schulte added: "By 1959, after only four and a half years of elevated temperature testing at 80 °C, an extrapolation of the time-to-failure values obtained provided an indication of the service life for the pipes made from Hostalen HDPE undergoing the test over a period of 50 years at 20 °C," said Schulte. "It is gratifying to know that today, more than half a century later, the results of the long term creep tests (at 20 °C) initiated by those pioneers working on the Hostalen grades, correlate with the service life potential for pipes which they indicated so long ago."
The Hostalen GM5010 test findings are significant, Schulte pointed out, because the same extrapolation method is used to provide an indication of the service life of today's improved generation of Hostalen GM 5010 T3 Black and Hostalen CRP 100 Black and Blue pipe materials.
Basell is the world's largest producer of polypropylene and advanced polyolefin products, a leading supplier of polyethylene and catalysts, and a global leader in the development and licensing of polypropylene and polyethylene processes. Basell, together with its joint ventures, has manufacturing facilities around the world and sells products in more than 120 countries.
