Application of Adhesive on Rotor Blade Shells

Task

Application of a 2-component adhesive on various geometries of rotor blade shells of a wind-power-plant rotor blade size E 82.2. There are 4 forms in a row (length of the plant 214 m). One portal can be fastened only on a wall-sided guideway. A second support needs to be provided on the floor side.

Adhesive application:
In the first step, stays need to be glued in in the longitudinal axis of the pressure-sided rotor blade shell half. After the stays in the rotor blade shell have cured, adhesive needs to be applied on the topside of the stays as well as on the seam edges (trailing edge and leading edge). In the stay area, the stay contour needs to be traced by a sensor. This is necessary due to the flexibility/lability of the stays.
In the seam area, the adhesive needs to be applied as continuously as possible from the flange (hub-side connection) to the tip (end of a blade) in various adhesive bead contours.
All adhesive tracks are located on the 3-dimensional contours of the rotor blade.
The shape of the adhesive bead is divided in triangular beads and flat beads, each in various types (width, height and contour).

Solution

A special FP6 is used with a wall-sided X-beam. The support towards the floor middle is provided by a co-traveling extra support instead of a 2nd X-beam. 

Synchronization X1/X2-axis:
By a self-monitoring correction compensation between the X-drive (pinion – rack) on the wall wide and the friction wheel drive on the floor side the problems with the synchronization of both drive systems could be could be solved. A 2nd Y-beam parallel to the actual Y-drive-beam spans the area for a platform on which the complete control system as well as the adhesive system can be mounted. The energy supply was realized by a collector system.

Operation of the plant:
Due to the presence of further personnel in the near vicinity of the personnel present during the automatic operation, it is required for safety reasons to drive it at a maximum safe speed (0.25 m/s). This feeding speed is sufficient enough though based on the adhesive amount to be applied (400 kg / rotor blade).
In the automatic gluing process, the task of the operator is solely in the qualitative monitoring of the adhesive bead. The plant is moved manually by the operator only for moving between the forms (similar to a hall crane). Various other safety equipment (safety bumper, emergency-stop buttons, as well as optical and acoustical signals) continue to secure the gantry during automatic mode.

Hand axle:
To realize the 3-dimensional contour drives, a manual axle with A-, B-, and C-axis was integrated in addition to the gantry's own X-, Y-, and Z-axis. This guides the nozzle along a taught contour. This contour was recorded from a master form and transferred to the further forms by an axis transformation.

Gluing plant:
This was mounted on the gantry platform and carries along the two adhesive components in sufficient amounts for a complete rotor blade. Via an interface to a stationary tank system, new adhesive can be loaded semi-automatically.
The gluing plant itself provides the two adhesive components in the respective necessary quantities. A mixing takes place just ahead of the gluing nozzle.
The respectively required quantity of adhesive is provided by a combination of the adhesive flow rate and the feeding speed of the gantry.

Scope of supply

1. Surface gantry FP 6 special with X-stroke: 214,000 mm; Y-stroke: xxx mm; Z-stroke: xxx mm
2. Manual axle with A-, B-, and C-axis
3. Gluing plant, incl. gluing nozzle equipment

Result

Thanks to the automatic adhesive gantry, it is possible for the end-customer to apply the hitherto manually conducted adhesive application in a significantly better quality and quantity.  Due to the non-stop application of adhesive, the air bubbles in the adhesive are minimized or otherwise avoided completely. This is one of the most important quality criteria during the production of a rotor blade.
Furthermore, the adhesive amounts can be reduced to an absolute minimum due to the repeat-accurate application (costs adhesive: about 6.- €/kg)
Personnel requirements can be reduced from about 15 persons for manual application to about 3-4 persons. The time for applying the adhesive was reduced to 30 minutes per blade. Thus, the productivity of the entire plant can be improved significantly.