Huge Rotors Made of Lightweight Polyurethane Infusion Resin
Wind turbine rotor blades are generally made out of resin. Now Covestro has made the first blades out of polyurethane infusion resin. This allows the blades to be made longer and stronger.
Covestro has commissioned its first wind turbines with rotor blades made of polyurethane infusion resin. The spar cap and shear web of the 55.2 metre-long blades for the 2MW wind turbine were fabricated from the lightweight, high performance polymer. Therefore, according to the manufacturers, it is now possible to form the longer and stronger blades required by the wind power industry. This turbine was installed recently at a wind farm in Tieling, Liaoning Province, Northeast China, operated by Liaoning Datang International New Energy Co., Ltd.
The development process involved the participation of Covestro R&D teams around the world and is enabled by close collaboration along the value chain including blade manufacturers, turbine manufacturers, glass fibre producers, machine suppliers and blade designers. New turbine blades must undergo extensive independent testing to obtain all relevant certificates. Covestro says it has thoroughly tested the performance of the wind blades used in the turbines, and they successfully passed the static test and fatigue tests both edgewise and flapwise conducted by China General Certification.
High operational capability and stability of the rotor blades
In addition to the installation of its own commissioned wind blades in Northeast China, Covestro also partnered with one of China’s leading wind turbine manufacturers to develop another 2.2MW turbine with 59.5 metre long blades, whose spar cap, shear web and blade root were fabricated with Covestro’s polyurethane infusion resin. The turbine has been installed in South Central China. Julien Guiu, Vice President Industrial Marketing APAC, Polyurethanes Business Unit, Covestro, said: "With two wind turbines now installed at wind farms across China, we are able to test the operational feasibility and stability of the wind blades in different wind conditions. This will provide valuable data that can inform new blade designs."
Wind turbine rotor blades are typically made out of fibreglass reinforced resin through vacuum infusion technology. The successful use of polyurethane composite for manufacturing large-scale wind turbine rotor blades suggests that the polyurethane resin itself features superior mechanical properties and anti-fatigue performance. There are also benefits to production processes in the wind blade factory, with a faster curing process and better processing properties that can deliver higher levels of productivity.