Plastic Pipes Conference Association # 2010 Vancouver
P.Micic
Bimodal HDPE resins exhibit superior performance characteristics relative to traditional unimodal resins for polyethylene pressure pipe applications and have been the resin of choice for PE-100 pipe markets. These PE-100 resins provide an improved balance of stiffness, slow crack growth resistance, and resistance to rapid crack propagation. These raw material improvements have allowed production of pipe with higher operating pressures, higher margin of safety, and thinner pipes leading to raw material savings. Until recently, these materials have been produced via staged-reactor processes, either dual slurry, dual gas-phase, or dual-slurry-gas-phase systems. In recent years, a proprietary Bimodal Catalyst system for producing bimodal HDPE resins in a single gas-phase Reactor has been developed. This unique catalyst system produces a HDPE polymer with bimodal molecular weight distribution and a favorable comonomer distribution. Single reactor/Bimodal catalyst produced resin exhibits an excellent balance of hydrostatic strength, slow crack growth resistance, resistance to rapid crack propagation, and processability.
Related papers
Author(s) : Predrag Micic
The Polyethylene (PE) pipeline business is constantly experiencing change. In the not too distant past, lower performance materials and a lack of understanding of major risks to pipeline structural and operation integrity meant that we needed standards that ensured a good quality pipe, careful installation and a...
Author(s) : Predrag Micic, Cliff Mure
An extensive investigation was conducted into the electrofusion compatibility of pipes produced using a PE100 resin with an MFR5 value below 0.2 g/10min. The electrofusion (EF) joining program included pipes up to 800 mm in diameter and the use of electrofusion couplers and saddle type fittings as well as varying...
Author(s) : Dr Predrag Micic, Mr Gerald Beckton
The urgent diversion of a river through a rapidly constructed pipeline was required to avert a power supply crisis to the state of Victoria. In early June 2012, the Morwell River surged and a levee collapsed allowing the river to flow directly into the open cut coal mine which supplies the Yallourn power station. The...
Author(s) : Micic Predrag
Large diameter polyethylene pipe played an important role in ensuring water supply security to the Shortland region near Newcastle in NSW Australia. After 85 years of operation, the pipe owner, Hunter Water, decided to replace 7.4 km of above ground 900mm metal pipe that had been prone to flood damage and regularly...