Bayer MaterialScience LLC, the US arm of Bayer MaterialScience (BMS, Leverkusen / Germany; www.bayerbms.com), has developed, in cooperation with Molded Fiber Glass (Ashtabula, Ohio / USA; www.moldedfiberglass.com), a new class of polyurethane-based composite systems for use in large windmill blades, that are said to improve performance.

In research conducted by the partners, blades made with Bayer’s “Baydur” resin infusion polyurethane systems are claimed to have outperformed the epoxy and vinyl ester samples in tensile fatigue, interlaminar fracture toughness testing and fatigue crack growth testing.

According to Bayer, the glass fibre-reinforced PU composites traditionally used in agricultural, construction and marine applications, were unsuitable for large windmill blades, as they require lower viscosities and longer gel times. The Bayer PU systems, with low-to-no volatile organic compounds and based on renewable raw materials, were adapted to current large blade manufacturing processes and retrofitted into existing designs “at minimal cost,” the companies said.