The BMW Group is piloting a new overspray-free painting process that allows several paint colours to be used and designs to be applied without stencils or masking the vehicle.
It says the application method not only increases the degree of individualisation for customers, but also contributes to sustainability by reducing waste and energy consumption.
The technology is being used for the first time on 19 BMW M4 Coupé models, which will soon roll off the production line at the car maker’s Dingolfing plant in Germany with custom two-tone paintwork and M4 identification on the bonnet and tailgate.
The BMW Group developed the new EcoPaintJet Pro application process for waterborne base coats and 2K clear coat in collaboration with mechanical and plant engineering firm Dürr.
In the conventional procedure, paint is atomised by a rotating bell with 35 to 55,000 revolutions per minute and adheres electrostatically to the body.
The new method works without electrostatics, relying instead on jet application. The paint is applied using an orifice plate that enables high edge definition with a variable paint thickness of between one and 50 millimetres, according to BMW. This requires maximum precision from both the robot and application technology.
It also means two different colours of paint can be used, e.g. for a contrasting roof, and stripes and other designs applied – for instance, on the bonnet. The focus of technology and material development was on achieving the maximum range of applications.
“It will now be possible to paint every exterior component – offering customers virtually limitless options for individualisation,” a representative from the German car maker claims.
They add: “Until now, custom designs like this can only be realised using manual masking. With the new technology, the material and personnel costs this previously entailed will be eliminated, making it possible to realise these options at a lower cost.
“This innovative process also prevents so-called overspray, i.e. excess paint particles, which therefore no longer has to be disposed of.
“A further contribution to sustainable production comes from lower energy consumption: Since paint separation is no longer required, the amount of air needed is also lower.
“At around 7,000 operating hours, this results in energy savings of more than 6,000 megawatt hours and reduces the carbon footprint by nearly 2,000 tonnes per year. Development of innovative paint technology for further series applications will continue.
“With the paintwork for the M4 small series, the BMW Group is testing the possibilities of the new process. These unique vehicles will initially be used in the company’s own fleet. Series introduction of the piloted paint process is scheduled to begin in 2022 in the BMW Group production network.”