In addition, the process of laying-up the fabric in the mould without wrinkles is reported to be significantly improved, thereby shortening the lay-up time.
Wind turbine blades are exposed to strong mechanical forces, Saertex explains. The lighter the materials, the more efficiently and economically the turbine operates. Lightweight components therefore dominate the market for the production of modern wind turbines. By laying fibres in a specific direction, composite components made of multiaxial interlaid complexes make it possible to transfer the generated stresses through the component in the direction of the applied load in an ideal manner. The spar cap of a rotor blade is one of the composite elements that is exposed to the highest stresses.
Saertex reports that it has managed to achieve higher mechanical values and simpler material handling through the development of unidirectional fabrics used in the spar cap. The fibres now remain stretched and this provides the composite component with a tensile strength that is up to 20% higher than with conventional glass UD fabrics. During infusion, resin accumulations between the fibre strands are also reduced, which improves the laminate quality. Laying-up the fabric in the mould without wrinkles not only simplifies handling for the customer, but also shortens the lay-up time during rotor blade production by up to 15%, the company states.
“We have managed to meet the ever increasing requirements for rotor blades in wind power generation,” says Steffen Baitinger, Wind Power Application Technology at Saertex. “The turbines are becoming ever larger and this places enormous demands on the stability and (flexural) rigidity of the reinforcement materials used in the rotor blades. The new glass UD fabrics are our response to market requirements and they guarantee our customers a higher quality of their composite components.”