# 2010 Vancouver
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.