New PE Materials with Step-Out Stress Cracking Resistance for Piping Technologies [PE]

PE Pipe materials have always been a compromise between a set of requirements. On top of the expectation from pipe makers to have a good processability, end users would expect for the guaranteed long life of pipes made of PE a minimum requirement on • Stiffness, yield strength, hydrostatic strength or Minimum Required Strength (MRS) • Long term ageing resistance, slow crack growth (SCG) resistance or environmental stress crack resistance (ESCR) • Impact resistance or rapid crack propagation (RCP) resistance After gathering experience for years of trouble free operation of PE pipes, end users are looking to use this type of pipes in more challenging environments (trenchless technologies, sandless laying of pipes etc) offering one next step of economical advantages. Industry recognises today that for this type of challenging environments, more requirement need to be met by the raw material as well. We present materials with proven resistance to the most challenging environments in this paper. Specifically, the resistance to stress cracking has to be improved to allow to pass the 50 years guaranteed lifetime also in rocky soils or other environments with high point loads.