Polyurethane for wind turbine rotor blades
Polyurethane (PU) is ideal for manufacturing wind turbine rotor blades. It offers advantages over other plastic systems such as epoxy and unsaturated polyester resins in terms of process, cost efficiency and mechanical properties. A tailored polyurethane system has now proved it's mettle in commercial wind power generation.
Making a contribution to climate protection is a fundamental part of Covestro's commitment to sustainability and to its corporate strategy. The Group follows a climate protection program dedicated to improving the resource and energy efficiency of chemical production methods, for example, and to developing technologies for generating power from renewable sources. One focal point is wind power.
Covestro founded a Wind Power Competence Centre in Otterup, Denmark, that coordinates the subgroup's global activities for sustainable power generation. The centre together with the regional development hubs in Leverkusen, Germany and Shanghai, China, focuses on new materials and new or optimized processes that enable processors to produce components cost-effectively while delivering a high level of productivity and quality One example of this material and process expertise are the new polyurethane systems from the Baydur® product family that have been optimized for the production of wind turbine rotor blades using vacuum infusion technology.
Vacuum infusion — a method of choice
The vacuum infusion method used to manufacture rotor blade half-shells is based on core materials such as balsa wood or foam and continuous glass strand fabrics that are placed in a mould prepared with a release agent. Infusion channels are distributed throughout the mould as a function of the size and geometry of the rotor blade. Before the infusion process starts, the entire structure is hermetically sealed with a film and a vacuum is applied to remove all the air. A metering machine pumps the infusion resin's liquid reaction mixture through the composite structure. The advantage of this method is that the reinforcing glass fibre fabrics are saturated evenly without any bubbles. Heat is then applied to the mould, which triggers the chemical reaction of the infusion resin. The resin solidifies and cures. Finally, the blades and half blades are demoulded and the film is removed.
Key advantages with Covestro polyurethane resin:
- Increased performance
- Fast production
- Lower costs