Integrated Design and Manufacturing Approach for a Faster and Easier Production of Rotor Blade Molds—Direct Tooling by BladeMaker

Abstract

Blade mold production is a fairly standardized process in the wind turbine industry. Nevertheless, a significant reduction of production costs can be obtained through a novel process, greatly reducing the time-to-market of new rotor blades. Current mold production processes are based on the production of a positive master plug. The negative mold itself is then built up on the master plug. After lifting the mold off the master plug, the mold is mounted to a steel framework and equipped with a heating system. The novel direct tooling approach of BladeMaker tackles three domains: mold design with integrated functionalities, integration of the mold manufacturing preparation process into the mold design and the manufacturing process itself. Fraunhofer IWES has set up an integrated digital tool chain, spanning from blade design down onto the shop floor. The blade geometry, generated in CAD, is directly employed for the mold design mold and the mold geometry is transferred to the CADCAM- solution for the automated 5-axis-milling of the mold. The mold geometry is e.g. milled out of polyurethane foam blocks used as the core of the mold sandwich shell. In the next step, carbon fiber fabrics are laid on the core for the structural stiffness and as the heating system. This carbon fiber based electric heating can be used for high process temperatures well above 100°C and achieves high heat-up rates and a constant temperature across the entire surface. The drafted mold making process can also be conducted with different materials, e.g. additively manufactured foam components. Fraunhofer IWES has executed and evaluated this process in their BladeMaker Demo-Center with its CNC-equipped multi-functional lightweight carbon fiber gantry robot and will present the results for all affected domains of mold making.