But let’s stay with the oven for the moment: EcoInCure features nozzles with long throw distances that blow hot air into the inside of the body through the opening for the windshield. The flow velocity around the outer skin of the body during this process is minimal. This results in an undisrupted paint appearance with maximum quality. At the same time, optimum transfer of heat inside the body enables extremely homogeneous heating of both thin sheet and mass parts. The result is up to 30% shorter heating times with minimized thermal component stresses, which is especially important for drying electric vehicles and multi-substrate bodies. The heating concept of EcoInCure reduces the electrical energy requirement by 25% and regulates the drying temperature with previously impossible precision and speed. The exhaust air from the ovens is purified via the integrated Ecopure® TAR afterburning system with heat recovery and then used for the oven heating system.
The entire plant including data acquisition, data evaluation, and plant monitoring is controlled by the Dürr software solution iTAC.MES.Suite. The modular MES system provides detailed information on the production workflows and the consumption data at all times. For the first time, for example, Dürr is using the electronic quality card for the drying process, which makes it possible to track the drying quality of each body.
Before the bodies are given their top coat in the painting booth, they undergo pretreatment (PT) and electro coating (EC). The RoDip® E rotational dip process is used for cleaning and applying the corrosion protection. The rotation of the entire body optimizes the immersion, flooding, and draining process. This tried-and-tested technology from Dürr is already used to coat well over 10 million bodies worldwide each year.
The use of the RoDip® E version with electric drive in PT and EC means that there is a separate drive for the rotation in each trolley in addition to the conveying drive. The individually programmable trolleys enable optimized dip curves for the respective body, which results in better coating quality.
The latest Dürr robotic generation is used in all process steps involved in painting. From the primer to the base coat and the clear coat line, a total of 61 EcoRP third-generation painting robots ensure efficient paint application. The exterior painting is done by the EcoRP E043i, the first painting robot where the seventh axis is integrated into the robot’s kinematics. Two or four robots are installed in each of the exterior painting cells. The stop-and-go painting process means that they do not need a rail. This enables a much better view of the booth, and eliminating the positioning axis significantly reduces the maintenance effort in the robot cell.
The interior painting stations are equipped with the six-axis robots of the type EcoRP L133i, which are mounted on a rail. The identically constructed EcoRP L033i model without rail is used for opening the hoods. The robots are assisted by Scara door openers. The latest Dürr robot generation has a modular structure. The only difference between the six- and seven-axis models is the additional axis of rotation in the main arm. The otherwise identical components simplify spare parts management, save storage costs, and make maintenance easier.
The robots are equipped with the latest Dürr application technology. The EcoBell3 atomizer series together with the associated EcoBell Cleaner D2 and the EcoLCC2 color changer delivers low paint and solvent consumption as well as fast color changes within the cycle time.
The third generation of Dürr robots is controlled by the also newly developed EcoRCMP2 process and motion controller. The control platform combines a multitude of sensors and actuators in the painting robot and the higher-level maintenance or control systems. An integrated interface makes the robot “cloud ready” and provides all relevant data for current and future requirements in the Industry 4.0 landscape.
Even before the bodies get their layer of paint, the welding and gluing seams are sealed fully automatically. This ensures that no water can infiltrate into the vehicle interior later. Dürr is installing a total of 19 EcoRS sealing robots with the latest application technology at ŠKODA in Mladá Boleslav. These robots undertake the task of sealing the seams from below, inside the body as well as at the roof seams. Since the standardized EcoGun2 3D is suitable for all fields of application in seam sealing, only a few spare parts need to be kept in stock.
Gaps at doors, the hood, and the tailgate are sealed during this process. The fully automatic seam sealing also requires high precision, since the conveyor technology is subject to certain tolerances. Special nozzles are used for the hemflange application on closed doors and hoods. The entire paint and high-viscosity material supply for the painting and sealing stations is also supplied by Dürr.
The EcoDryScrubber, a dry separation system with limestone powder as the binder, will take over the paint overspray separation in the spray booth. This system requires no manual handling as it is fully automated, robust, and easy to maintain, and requires no adaptation to different paint systems. This makes it ideal for high-volume plants such as at ŠKODA. An important point is the energy saving of up to 60% in the spray booth. By completely eliminating water and chemicals, up to 90% recirculated air can be used in production. This reduces the cost of conditioning fresh air and is the deciding factor in the outstanding energy efficiency of the spray booth.
The performance of the EcoDryScrubber is further improved through the use of the new V5.X system software. It enables the system to be self-regulating. As a direct result, optimum use is made of the limestone powder for binding the overspray, thereby reducing consumption.
The use of the EcoDryScrubber has a special side effect in Mladá Boleslav: using the limestone powder in the paint shop is only its first use. The limestone powder saturated with paint can be used as a heating medium in the factory’s own generating station, which means that no waste is produced thanks to the dry separation system.
The dry separation system results in highly concentrated and especially efficiently filtered exhaust air. This enables a very compact air purification system, consisting of a highly efficient VOC adsorptive concentration system (Ecopure®KPR) with downstream thermal exhaust air purification system (Ecopure® TAR). The energy needed for the Ecopure®KPR system’s desorption air is recovered from the purified gas of the thermal exhaust air purification system. This reduces the investment costs for the exhaust air system by 60%. The energy requirement for exhaust air purification is reduced by 80% in this combination.
The plant is designed for a throughput of 30 vehicles per hour, and will be painting ŠKODA’s mid-range models from June 2019.