Wind powerWinding technology and pultrusion for rotor blade production - with a new epoxy system and polyurethane resin
At the JEC, BASF will present two new materials that can be used in processes for manufacturing components used in wind-based power generation. Root segments for rotor blades can be manufactured through use of filament winding technology. With its Baxxodur System 6100, BASF is able to offer a new epoxy system for the special requirements of this technology: the system (approved by German Lloyd) exhibits good impregnation characteristics and has an open time that permits production of larger parts. Filament winding technology simplifies the time-consuming production process for rotor blades which lowers manufacturing costs.
To securely attach the root of the rotor blade to the hub of the wind turbine, a fiber-reinforced component made from Elastocoat C6226-100 polyurethane resin by means of pultrusion can be used. BASF developed this resin to manufacture pultruded rods together with its partner Fiberline Composites A/S in Denmark. Pultrusion allows better alignment of the fibers as well as in-line incorporation of a threaded metal bushing. This ensures consistently high production quality and an extremely stable part. Furthermore, fewer process steps are needed in production, which reduces the manufacturing time and material costs. Both the pultruded part produced from the Elastocoat material and a 12-centimeter thick root ring manufactured from glass fiber-reinforced Baxxodur will be exhibited at the booth.
Blade cross-section demonstrates wide range of offerings
BASF will also present the cross-section of a wind turbine rotor blade that is intended to demonstrate the wide range of products and solutions available from the company for rotor blade manufacturing - from the Baxxodur epoxy resin system through Kerdyn PET (polyethylene terephthalate) structural foam and Relest gel coat system to Elastan semi-structural polyurethane adhesive. Under static and dynamic loads, the PET foam ensures stability. For this reason it is primarily used inside rotor blades. Kerdyn is certified by German Lloyd and available in densities of 80, 100 and 115 kilograms per cubic meter. Besides the wind power industry, the PET foam is also used in the transportation, construction and marine industries.
Next to the rotor blade cross-section, a spar cap is on display - manufactured with carbon fibers immersed in Baxxodur. Because of their strength and rigidity, these spar caps are being used increasingly for large rotor blades. During the infusion process, the Baxxodur system ensures fast and complete impregnation of the carbon fiber layers.
Overall, the range available from BASF encompasses a variety of epoxy resin and hardener systems, which addresses the trend toward ever larger parts as well as the increasing number of production processes encountered. The use of so-called latent hardeners gives processors a considerably longer processing time while simultaneously shortening the production time needed by up to 30 percent.