Statistical investigations into automated spray-applied stripe coats to complex geometries of floating offshore wind foundations

The automation of coating processes allows consistent, economical, and ecological applications. In this study, the effects of various surface geometries—steel plates, plates with weld seams, plates with bolts, and plates with welded fillets—on the uniformity of dry film thickness (DFT) after robotic stripe coating applications with an electrostatic spray device are investigated and analyzed with statistical methods. Robot traverse rate, pump pressure, and voltage. Based on analysis of variance studies, the robot traverse rate was identified to be the most influential factor. For plates with weld seams, an optimization study was conducted, resulting in a multiresponse prediction model. The model achieved a DFT within the target range across all measuring points within a 95% confidence interval. At an optimized factor combination (117 mm/s, 0.3 MPa, 61.4 kV), the DFT values ranged between 100 and 142 µm. The findings of this study provide fundamentals for achieving uniform coating distributions on complex geometries and for optimizing process parameters.