Xu Yijiong, Liu lIangbing, Dongyu Fang, Cindy Wang, Jarmo Juhani Harjuntausta, Youssef Taha
Papers # 2012 Barcelona
Key words : Corrugated pipe, PP-HM, PE, sewage, drainage 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 or higher stiffness products. This gap can be filled by high modulus polypropylene block co-polymer materials (PP-HM) and some Chinese pipe producers are now launching these higher stiffness pipes and fittings which are being welcomed in the market. However, since the pipe producers in China are only equipped with HDPE corrugators the question arises of how to utilize PE corrugators to make PP-HM twin walled pipes. This paper discusses how this question was addressed by changes to the processing conditions and the resulting differences in final pipe properties and characteristics. In China high quality twin walled pipes up to 800mm diameter have been produced using PP-B HM materials on standard HDPE corrugators which conform to a higher stiffness class (SN) at the same pipe dimensions compared than the equivalent HDPE pipes.