The BladeMaker project was funded by the German Federal Ministry for Economic Affairs and Energy (BMWK) to the tune of around €8 million and the BladeFactory project with around €9 million. The final conference with around 40 guests was held on Tuesday at ENIQ on the EUREF-Campus in Berlin.

Rotor blades account for around 20% of the total costs of a wind turbine. New materials and optimized processes should be utilized to optimize the manufacturing process even further and boost the quality – there is still a considerable amount of untapped optimization potential in the production chain. The goal is to produce rotor blades for wind turbines more sustainably, faster, and more reliably – and that as inexpensively as possible.

Setting up of the test environment at the BladeMaker DemoCenter

As part of the BladeMaker research project, Fraunhofer IWES has built and commissioned the BladeMaker DemoCenter in Bremerhaven over the last ten years, creating a realistic test environment in which holistic processes can be developed to further automate and industrialize rotor blade manufacturing. When doing so, the scientists investigate the rotor blade design, materials, and manufacturing processes to test the potential for implementing automation. Until now, many rotor blade manufacturing steps are performed one after the other and still manually in the main mold tool of the rotor blade blank. Among other things, the project team has succeeded in constructing a mold tool without first creating a 1:1 master model of the blade. Omitting this intermediate step allows manufacturers to shorten the production time by around two months. In addition, the use of an integrated software solution makes it possible to simulate 3D models of the individual components and thus prepare the manufacturing process with precision. The project also saw the development of a complex gantry robot on which different process heads can be installed and controlled in different ways: working steps such as milling, gluing, and grinding as well as the impregnation of the fiberglass fabrics can thus be tested in an automated manner. The BladeMaker DemoCenter was officially opened in 2017.

Automated solutions for rotor blade production

The goal of the scientists in the follow-up project BladeFactory was to further develop and parallelize the sub-processes and procedures. The individual process steps are to be integrated one by one into a coherent overall process: For example, the past five years have seen the development of the automated process of preforming, the automatic depositing and draping of fiber fabrics and core materials, and prefabbing, the prefabrication of rotor blade components. These processes also help to shorten production time, as they can be outsourced from the main blade mold tool and thus implemented in parallel.

The processes are accompanied by the use of measurement technology and mechanical testing to ensure reproducible quality. In addition, the researchers are utilizing a laser measurement system that records the 3D geometry of the finished components. The manufacturing process is becoming more efficient.

Heiko Rosemann, Project Manager at Fraunhofer IWES, explained:

»Today, we are celebrating the milestones of the past ten years. With our processes, we have been able to contribute considerably to shortening the production times for rotor blades and simultaneously improving the quality of the component. This reduces the risk of expensive reworking and material surcharges for the customer. We can produce a mold tool directly and even control and shorten the adhesive curing process with an integrated cooling function. The use of our Variable Glue Applicator means it is no longer necessary to change tools when gluing the shells and allows adhesive savings of up to 20%. We are proud of what we have achieved and look forward to developing solutions for the challenges ahead together with the industry.«

Dr. Alexander Krimmer, Senior Engineer Composite Materials and Structures, TPI Composites Germany:

»The speeding up of production processes and saving of material are some of the key tasks in rotor blade development. The test environment at the BladeMaker DemoCenter allows investigation of all aspects of automated production, which helps the industry to further optimize these processes. Fraunhofer IWES is making an important contribution to research and development with its work.«

Kai Ehrich, Group Lead Materials, Nordex Energy:

»The expertise of the IWES scientists plays a major role in enabling manufacturers to test new production processes and implement them on a large scale. With IWES’ help, we have been able to qualify our adhesive application and investigate what effects temperature and humidity have in blade production. The results allow us to make our adhesive process even more efficient.«

The test environment at the BladeMaker DemoCenter is being continuously expanded and also enables scientists to work across different groups. For example, special components made of fiber composites are also manufactured here for the rotor blade tests next door and sensory measurement technology is being developed.

Source: Fraunhofer IWES