Wang Liqun, Wu Gengtian, Qi Jun
5 minute posters # 2014 Chicago
In China demand is growing rapidly for large diameter plastic pipes due to urbanization and the need to protect the environment with improved storm-water management systems. Whilst plastic pipes are already used in China for underground sewage and drainage applications the properties and processing limitations of the materials used are such that they are not able to fulfill all the requirements for large diameter pipes in terms of the required ring stiffness and cost structure. This gap can be filled by high modulus polypropylene block co-polymer materials (PP-B HM). Large diameter spiral wound pipes with improved structural design were developed. The products reached higher stiffness at an economic cost which can meet the market requirements. In the paper the authors discussed the product design to reach optimized ‘pipe weight to stiffness’ ratio. A detailed comparison between large diameter HDPE and PP-B HM spiral wound pipes in terms of wall profiles and product weights and manufacturing costs was made. The procedure of the electrofusion of PP-B HM spiral wound pipe was discussed. Following extensive machine trials we are also able to define the optimum processing conditions for large diameter PP-B HM spiral wound pipes.
In the present paper, the development of high stiffness PP-B HM spiral wound pipe is discussed, combining PP-B HM material properties, spiral wound pipe structural design and improved processing conditions. In addition, electrofusion jointing of PP-B HM spiral wound pipe is also discussed. The developed PP-B HM spiral wound pipe meets the standards of EN13476 and ISO 21138.
