Apr 13 2010
The Multitec® polyurethane spray system from BaySystems has emerged as the top solution for RLE International GmbH, in its bid to optimize the manufacturing process for wind turbine nacelle housings.
RLE International GmbH, a versatile service provider in development, technology and consulting for the mobility and energy sectors headquartered in Cologne, Germany, is currently working intensively on developing wind turbines. In particular, it is focused on optimizing the manufacturing process for nacelle housings, which can take on a variety of forms in line with customer needs. The housing deadens the sound of the gear mechanism and needs to exhibit long-term resistance to weathering influences such as wind, precipitation and UV radiation.
The Multitec® polyurethane spray system from BaySystems meets all these requirements and is a highly versatile material that allows exceptional freedom of design and can be processed simply and flexibly. Initial tests on a housing from a small wind turbine manufacturer yielded highly promising results, allowing experts to start developing the production process immediately afterwards.
Housings for wind turbine nacelles were previously manufactured in a time-consuming process. Firstly, the two half-shells were produced using hand lay-up and then assembled to form the finished nacelle. Hand lay-up produces only a very minimal coating thickness, with inevitable consequences for mechanical strength. This is why stabilizing elements have to be bonded in following curing. Finally, insulating mats are installed for noise insulation. The entire manufacturing process is time-consuming, expensive and is based on the use of styrene-containing polyester resins.
With Multitec® the half-shells are manufactured first. After applying a gel coat as an initial layer, the multi-component system is sprayed directly into the open mold without adding glass fibers. This initial layer without glass fibers ensures a perfect surface. Only seconds later the next layers of Multitec® will be applied, this time with glass fiber reinforcement, which gives the composite the necessary stiffness. Circular inserts are then placed in the still moist surface.
Further foamed layers from the polyurethane system create additional stability and even perform the function of insulating mats. Using this integrated production method, the entire sandwich construction is also much lighter than with the conventional process, and the time needed is just a fraction of what was previously required. The use of styrene is no longer necessary.