Efficient coating for construction cranes reduces paint consumption

In order to make the coating of cranes more efficient, one manufacturer upgraded its wet painting process to electrostatic technology. This significantly reduced coating thicknesses and paint consumption.

Tadano Ltd., headquartered in Takamatsu, Japan, is a major manufacturer of construction cranes, mobile cranes and lifting vehicles. The company has a long history dating back to the development of the first Japanese hydraulic crane in 1955. Tadano is particularly well known for its mobile cranes, which are used in construction, infrastructure and industrial projects.

Tadano faced numerous challenges in its wet painting process, mainly due to the complex nature of its crane superstructures and the harsh environments in which they are used. Cranes require tough, scratch-resistant coatings, but the increasing demand for visually appealing and high-quality finishes has added to the complexity. Tadano vehicles are painted to order in a wide range of colors, with over 300 color variations applied annually. Tadano is therefore particularly reliant on manual coating by specialist personnel.

In addition, many vehicles are only painted after assembly, which requires efficient and even coating of complex, deep or hard-to-reach surfaces. With the previous wet paint system, Tadano applied an extremely thick layer to ensure sufficient coating quality, but this resulted in high paint consumption. The company's aim was therefore to modernize the coating process in order to increase efficiency and reduce material waste.

Wagner proposed the installation of 39 Puma 28-40 high-pressure piston pumps in combination with 39 GM 5000EAC electrostatic hand guns, which ensure excellent atomization with the ACF 5000SP nozzle. After comparative tests with other manufacturers, this solution proved to be the most efficient. The GM 5000EAC hand gun is very flexible and easy to use: The user can switch between three voltage settings - high, medium and low - directly on the gun without interrupting the painting process. Another particular advantage for Tadano was the automatic tension adjustment, which regulates the tension depending on the distance between the gun and the workpiece.

For smaller workpieces, the voltage can be infinitely adjusted (5-80 kV), which prevents excessive coating thickness and enables Tadano to coat workpieces of all shapes and sizes highly efficiently. "The reduced overspray and improved coating quality has minimized rework and allows us to coat complex areas more efficiently," explains Masaaki Sueura, Production Assistant Manager at Tadano.

Since installing the Wagner wet paint system, Tadano has been able to reduce the required coating thickness and paint consumption by around 20%, while at the same time significantly improving the surface quality. Another advantage of the electrostatic gun is its ease of maintenance, as it only has a small number of components. This allows Tadano to replace parts directly on site and thus minimize delays in production.

The Puma 28-40 high-pressure piston pumps contribute to the efficiency of the system: The air motor with special IceBreaker technology prevents ice formation and ensures consistently high performance in any working environment. The pumps work with particularly low pulsation, even at low operating pressure.

In addition to the technical advantages, Tadano was also impressed by Wagner's service, which provided reliable and direct support throughout the entire implementation and operating phase. "From the laboratory test to the introduction of the system, there was excellent cooperation with the Wagner service team. Problems were solved immediately and the whole process ran smoothly. Technical challenges were addressed quickly thanks to the very good communication with Wagner headquarters in Germany," explains Kai Shimizu, Production Engineer at Tadano. "Customer service has also been as responsive as we had hoped, and the prompt site visits mean we can get the most out of the equipment at all times."

The new wet paint system has measurably improved Tadano's production process: more efficient coating while reducing paint consumption and waste. The flexibility and reduced need for rework have streamlined the company's processes and ensure high-quality results, even with complex crane superstructures. (OM-4/25)