Bayer MaterialScience Develops Polyurethane-Based Composite Systems for use in Large Windmill Blades

Bayer MaterialScience has developed a new class of stronger composite materials in response to the wind power industry’s move toward developing and manufacturing longer, larger, more productive wind blades.

A Bayer scientist and a researcher from Moulded Fibre Glass conducted studies to compare the performance characteristics of the newly introduced Baydur resin infusion polyurethane systems versus those of epoxy- and vinyl ester-based composites.

Bayer explain the results of the studies and development of the low-viscosity, long-gelling polyurethane systems are detailed in a technical paper: “Polyurethane Composites for Wind Turbine Blades,” authored by Dr. Usama Younes, Principal Scientist with Bayer and Frank Bradish, a researcher with Moulded Fibre Glass Research Company. Dr. Younes will present their findings during the annual SAMPE Tech 2011 conference and exhibition, taking place October 17th – 20th in Fort Worth, Texas.

According to Bayer, these polyurethane systems were designed for fast throughput equipment and are known for fast gelling and fast de-mould properties. As such, these polyurethane systems were not suitable for making very large windmill blades, which require polyurethane systems with lower viscosities and longer gel times. However, Bayer say that the studies performed by Dr. Younes and Bradish demonstrated that new polyurethane systems have been developed and adapted to current large blade manufacturing processes and retrofitted into existing designs at minimal cost.

According to the results of the research, the new polyurethane-based composite systems outperformed the epoxy and vinyl ester samples in tensile fatigue, interlaminar fracture toughness testing and fatigue crack growth testing. The authors explain, “These urethane systems showed much improved fatigue and fracture toughness properties as well as faster de-mould than resins currently used in wind turbine blade manufacture.”

Bayer says the polyurethane systems are environmentally friendly, as they contain low-to-no volatile organic compounds and use sustainable raw materials from renewable resources.