Green painting

    The Volvo Trucks cab factory in Umeå can offer more than 850 colours to the customers. What the factory is proudest of, how-ever, is that it has the world’s most environmentally optimised paintshop.

    At the factory in Umeå nothing is impossible when the time comes for the customer to choose a colour.

    “We had a customer here who brought his wife along with him,” says Denny Westerlund from the factory’s press department. “She was a truck driver. When we asked the customer what colour he wanted, he turned to his wife. She was a bit taken aback at the question but after thinking a while she held out her hands for us to see her nail-polish and said ‘That’s the colour I want for the cab’.”

    No problem. They took a sample of her nail-polish so they could test their way to the final result, relates Denny Westerlund.

    “She got a cab that matched her nails. This is naturally rather an extreme example, but it nonetheless shows just what we can do here,” he says.  

    What the factory is proudest of, however, is its pro-environmental work. For many years now there has been a dedicated focus on creating a paintshop of absolute world class as regards both low solvent emissions and high energy efficiency. Every step of the process has been monitored down to the tiniest detail. Everyone has been encouraged to offer ideas and suggestions, and major investments have been made.

    And it has all brought results. Between 1999 and 2008, energy consumption dropped by 30 percent. Although that achievement is stunning in its own right, it is even more remarkable bearing in mind that the paintshop’s operations grew considerably during the same period. One of the reasons is that plastic body components, which previously were paint­ed at the factory in Belgium, are now painted in Umeå.  

    “If they are not painted in the same facility it is immensely difficult to exactly match the shade with the rest of the cab. That’s why we decided to bring home this operation,” explains Hans Wenngren, process manager for surface treatment.

    The energy saving was achieved by reusing the air in both the spray booths and other premises. The air from the other parts of the factory is used as incoming air in the process section, and about 75 percent of the air in the spray booths is reused. As a result there has been a major reduction in the need for fresh input air. Better planning and shutdown of facilities in the event of operational disruptions or when there is a break in the flow of cabs in the production system, for instance, has helped reduce energy consumption. Other energy-saving measures include the installation of more efficient electric motors.

    “We also started painting the plastic body components together with the rest of the cab. This meant the temperature in the paint curing ovens had to be reduced by just over 50 degrees, which naturally cut our energy consumption. And since we needed a lower temperature, we could switch from LPG to district heating for the ovens,” says Hans Wenngren.
    District heating has also replaced oil in the heating system, and now the remaining LPG in the afterburning plants will be replaced with DME produced from biomass. However, one of the most spectacular energy savings is without doubt the factory’s cooling system. The Umeälven River traces its route just outside the paintshop, and under that flows a subterranean ice-river that is cool all the year round. Its cold water is pumped through a two-kilometre-long pipe into the factory’s own water system.  

    “We use this water in various cooling operations. It has allowed us to replace many of the refrigeration units that used to run on cooling agents such as freon,” says Hans Wenngren.

    The paintshop has been modernised and production has been made more efficient in a series of steps, and as a result consumption of paint and solvent as well as emissions to the air have been significantly reduced. In 1998 these emissions were about 70 grams per square metre of cab surface.  

    “Today the figure is less than 10 grams, which is way below the EU’s limit of 55 grams per square metre. Although we still have some way to go, we’re delight­ed with the work we’ve done so far,” says Hans Wenngren.

    Text: Jenny Palm  Photos: Sören Håkanlind

    Other, Environment, Other
    Sweden, Umeå, Paintshop, Colours