One of the big factors in the price of producing a car or truck is energy. And one of the big users of energy in an assembly plant is the paint shop. According to Bruno Welsch, president of Dürr Systems (durr.com), the cost of energy in paint is “in the millions.”
So, as one of the leading paint system suppliers in the world (“When we do turn-key greenfields, we do the whole process: planning, engineering, manufacturing, installation, commissioning, all in-house,” Welsch says), there is a keen focus on developing the ways and means to reduce the energy requirements associated with its systems. The company has calculated that the average energy consumption to paint a car is on the order of 700 to 900 kWh; they’ve developed what they call the “Eco+Paintshop” that can reduce that to 400kWh or less. This, of course, necessitates a comprehensive approach, including minimizing the use of water and paint, and optimizing the air handling throughout the paint booth.
Two of the more recent technologies that the company has developed to reduce the cost-per-unit for vehicle painting are the EcoDryScrubber and the EcoBell3 atomizer. The EcoDryScrubber handles paint overspray. It’s a water-free process that uses limestone to bind with the overspray. The limestone can be recycled for use in cement. The EcoDryScrubber is effective in that it allows as much as 95% of the process air to be reused in the paint booth, resulting in an energy save on the order of 60%.
The EcoBell3 high-speed rotary atomizer has a transfer efficiency of greater than 80%, Welsch says, noting that other applicators on the market are on the order of 60% efficient.
He says that the EcoBell3 can be used with charged or uncharged paint, and on both interior and exteriors of vehicles in the same zone (as opposed to the conventional painting the exterior, indexing the car forward, then painting the interior). Thanks to the minimal overspray, Welsch says that a customer that has been using the EcoBell3 for a year has realized a $6-million savings on materials.—GSV