S. COOK, C. DAL POZZO
Development in Plastic Materials # 2004 Milan
In 1989 the English and Welsh water industry was privatised. A research program was conducted to develop new testing and quality procedures. So many pipes, taken from mains placed in service over time, were disinterred and tested. The failure causes were analysed mainly by application of “fracture mechanics”. To try to examine the long-term transition in failure mode (ductile-brittle) we must know the conditions that control the initiation and growth of crack. The concepts of toughness and fracture mechanics were introduced. The tests were carried out on pre-notched samples cut in form of C-ring. Following an extensive research program it was established that adding an elastomeric modifier such as CPE to PVCU, the yield stress or strength was reduced a little compared to PVC-U, but the toughness is enhanced, so we always have a ductile material. This research allowed the development of PVC-A (A=alloy). It meets the requirements of BS PAS 27 of 3/99. It is approved by the UK Drinking Water Inspectorate.
Author(s) : Cook
The Natural Step is an international NGO dedicated to Sustainable Development. The work we do is based upon a scientific approach and began with scientists and businesses in Sweden over ten years ago. Our framework uses science and systems thinking to help others get to grips with the complexities of...
Author(s) : Cook
The properties of Hep30, an alloy of PVCU, PE and acrylic derivatives are described in terms of performance during handling and installation and performance during service.Details of tests demonstrate new levels of performance in the product and increased reliability in the long term properties of the plastic alloy....