# 2001 Munich
The introduction of bimodal polyethylene materials for piping systems such as PE100 and third generation PE80 HD has reinforced the trend from traditional to PE materials in piping systems for drinking water and gas applications. Improved physical properties and cost effective piping systems have increased the competitiveness of polyethylene versus other materials. Significant polymerisation process and product developments have continued and today advanced bimodal LLD to HD products are offered for a wide range of application areas including film, blow moulding, wire and cable, and not the least pipe. Independent design of molecular weights, molecular weight distribution, comonomer contents and distribution have provided tools for optimisation of processing as well as the short term and long term product properties. The development of Low Sag technology has extended the use of PE100 to very large diameter thick-walled pipe. Using these materials the sagging of the pipe during extrusion has been minimised and therefore the full economic potential of PE100 in large pipe sizes can be realised. Nearly twenty years after medium density polyethylene was introduced for drinking water and gas pipes in Europe, a new generation of flexible PE80 MD represents the next step forward. PE materials have been designed for better processing properties, enhanced slow crack resistance offers new possibilities for optimised installation techniques and rapid crack propagation resistance is increased, which could allow for higher operating pressures in the future. The opportunities for bimodal PE optimised polymer design is also expanding into other pipe application areas such as conduits, pipe profiles, sewerage and corrosion protection of steel pipes. The utilisation of improved bimodal polymers will continue to expand even further.