Saudi plastics and chemicals giant Sabic (Riyadh; www.sabic.com) has announced the development of a new range of polyethylene and polypropylene resins, which it claims will considerably boost the performance profile of polyolefin pressure pipes.

Developed with pipe manufacturing specialist Tecnomatic (Azzano S.Paolo / Italy; www.tecnomaticsrl.net), which has conducted trials of the new materials, and aquatherm (Attendorn / Germany; www.aquatherm.de), Sabic said its new “BiAx Pipe” technology performed better than existing PE and PP pipes across all performance criteria.

The Tecnomatic trials saw pipes being conventionally extruded with thick walls and small diameters, then drawn over a heated mandrel and stretched in two directions to obtain larger diameters and thinner walls.

Benefits of the new resins include higher resistance against internal pressure, which enables wall-thickness reduction – reducing material usage by at least 30% – while resistance to slow-crack growth meant pipes made with the new materials could be installed without the need for trench work. Sabic said the smooth inner wall surface of the resulting pipes reduced the energy required for pumping, while the technology meant the pipes were more resistant to abrasion, and so extended their lifetime. The group also claimed that the new PE and PP pipes promised better resistance to disinfectants, a lower coefficient of linear thermal expansion, and improved low-temperature impact strength.