Dürr is currently building two state-of-the-art paint shops in China for manufacturer of heavy trucks, Sinotruk.
Dürr is building two paint shops in Laiwu and Zhangqiu, in the eastern Chinese province of Shandong, for the manufacturer of heavy trucks, Sinotruk. The paint shops, equipped with state-of-the-art technology, will be used to coat Sinotruk subsidiaries Ji’nan Truck and Ji’nan Commercial Vehicle’s truck cabs and pick-ups, including flagship brands such as Yellow River, SITRAK, and HOWO, with which Sinotruk aims to enter the league of world-class manufacturers.
The Sinotruk plants are scheduled to start production in 2021 and 2022, respectively.
Flexible conveyor technology with AGVs
At Sinotruk, Dürr’s automated guided vehicles (AGVs) will transport truck cabs for the first time.
In order to move the heavy loads, the EcoProFleet has been designed with an unladen weight of 850 kg in good proportion with the maximum load capacity of 1,000 kg. The fleet is intelligently controlled by the DXQcontrol software, making sure that all AGVs execute their transport assignments and are permanently on the move. The energy concept with supercap technology also contributes: AGVs are charged within just 1.5 minutes, and at charging points where the AGV is stationary anyway for picking up or setting down the bodies.
The coating process
The Sinotruk paint shops feature the RoDip rotational dip process, which provides the optimal prerequisites for subsequent processes. The electric variant RoDip E permits individual dip curves for pretreatment (PT) and cathodic electrocoating (EC), which optimize the coating quality when dealing with different cab models. With this method, each cab is transported through the complete PT and EC process using a freely programmable trolley. Each trolley has a conveying drive and a rotating drive, which enable horizontal and rotating movements to be controlled independently of each other for each cab. The immersion tanks for the rotational process are smaller than with a traditional pendulum conveyor, which means that less energy and chemicals are required, saving resources and reducing operating costs.
In each of the two paint shops, two EcoRS sealing robots seal the inner seams and another two apply liquid sound deadener in a fully automatic process.
The base coat and clear coat in each paint shop are applied by 19 of the latest generation of EcoRP painting robots, which are equipped with EcoBell3 high rotation atomizers, which ensure optima painting results in terms of color shade and flow values, as well as particularly uniform layer thicknesses. At the same time, the Dürr application technology creates less of an impact on the environment thanks to high rotation atomizers with electrostatic charging that are extremely efficient in their material use. With the color change technology and the EcoBell Cleaner D2 for cleaning atomizers, paint loss during color changes and consumption of flushing agent and solvent (and thus VOC emissions) are also minimized.
The EcoDry X dry separation system, which doesn’t require water or chemicals, is another technology used in the new Sinotruk paint shops. The system uses inexpensive cardboard filter boxes to efficiently separate overspray and, if necessary, saturated filter boxes can even be replaced during production time.
At the end of the painting process, the body surface is checked at a fully automatic quality control station. Here, a robot follows defined checkpoints on the truck cabs and uses sensors to record data about color variations, surface texture, and layer thickness. This automation saves time compared to manual measurement. This data is transferred to the database and visualized digitally for the worker. This way, the worker always has an eye on the quality.
Testing technology
Dürr has also implemented end-of-line testing technology.
In Laiwu, four x-wheel truck d test stands equipped with high-precision 3D measurement technology are used to measure and adjust the vehicle axis geometry. Dürr meets the specific requirements of the heavy trucks in terms of load carrying capacity, wheelbases, and tracks widths with components specially developed for this area of application. The safety-relevant driver assistance systems of the trucks are precisely adjusted using Dürr test technology. With the modular test stand concept x-DASalign, the sensor technology for the lane departure warning system and the advanced emergency braking system are perfectly aligned in relation to the geometric driving axle of the respective vehicle.
Sinotruk also ordered additional test stands for another plant in Zhangqiu in August 2021. The production plant for light trucks will use the x-wheel wheel alignment stand with the latest x-3Dsurface measurement technology and the multifunctional roll, brake and ABS test stand x-road medium truck.