Digital laser template from LAP is more precise and over 20 percent faster

Lüneburg, 13.01.2012. Rotor blades of wind turbine generators have to be as light as possible, and nevertheless sturdy. They are therefore manufactured as sandwich constructions of fibreglass, carbon fibres and wood. In order to improve the complex production process, largee manufacturers are replacing the manual templates used to date for positioning the fibre mats. The new COMPOSITE PRO digital laser template from LAP ensures higher precision and significant savings in time.

The rotor blades of the wind turbine generators are the major determining factor for the output of a wind turbine generator, and are therefore a key component.

In this process, the mould is alternately filled with fibre material and liquid resin. Up to seven layers of fibre material are embedded in a matrix of thermoset polymer resin. The mould is finally sealed with film and evacuated. The air pressure presses the layers together and fixes them. These intermediates are then joined together to form rotor blades only at the final assembly stage.

Laser template works faster and more precisely
Particularly critical during production of the up to 60 metre long semi-monocoques is the exact positioning of the individual layers. Until now the individual mats made from the different materials have been positioned and measured time-consumingly using templates. As working with templates is susceptible to error, however, manufactureres are to start using the new COMPOSITE PRO laser system from LAP, a digital laser template specially for composite materials.

According to a development engineer from a large manufacturer of wind power systems, they expect the cooperation with LAP to result in time savings of over 20 percent in some areas of production, and to lead to a further optimisation through an in-production analysis of the processes.

"The COMPOSITE PRO systems project the exact position of the individual mats and a clear identification number by means of laser beams," says Axel Rieckmann, Sales Manager Industry at LAP, describing the process. "Alignment of the parts using the clumsy templates and the laborious manual measurement are eliminated, offering higher precision and considerable savings in time. Furthermore, the correct position of the mats in the curved mould is checked during production by means of laser projection. Errors in production can thus be ruled out from an early stage."

Lasers show every work step
The LAP projectors guide the employees step-by-step through the whole production process; the individual work steps are displayed in the correct sequence. All the elements are thus precisely positioned at exactly the right time, checked and documented, because scrap is an absolute no-go during the production of the expensive rotor blades.

LAP is the only manufacturer of laser projectors that can project three colours at the same time. This allows selected areas to be highlighted. By changing the colour from red to yellow or green, the system can signal which parts are to be processed, are in process or are already finished.

Thanks to LAP: Coordinated cooperation in production worldwide
A further crucial advantage while producing rotor blades is also that the different works at the locations worldwide can communicate via the new system. Axel Rieckman explains: “Transport of the rotor blades of the ever-larger wind turbine generators is extremely costly. Until now we have therefore needed complete sets of templates for the individual rotor types for each production location. In addition that meant that the slightest change necessitated new templates for all the locations. That is finally eliminated with the new projection system. With the new LAP system COMPOSITE PRO important information and modifications can simply be sent online."