Modern powder coating system for trailer couplings

A powder coating system for trailer couplings has been modernized. The previous four powder booths have been reduced to one, resulting in easier color changes, lower powder coating consumption and higher quality.

VBG Truck Equipment in Vänersborg, a Swedish manufacturer of trailer couplings and other products, has had its own powder coating facility since 2001. After 24 years, however, the plant no longer met modern requirements and spare parts were becoming increasingly difficult to obtain. While four separate powder booths were previously in operation, the process has now been converted to a single, completely modernized booth, which was installed during the summer production shutdown. The result: easier color changes, higher coating quality and lower powder consumption.

VBG's coating system already met the strict standards of the automotive industry. The processes include blasting, zinc-manganese phosphating, cathodic dip coating (CDC) and powder coating. As part of the modernization, the focus was on renewing the powder booth and the associated technology. A new oven for powder coating had already been installed and a new oven for cathodic dip coating is also planned.

The old system consisted of four booths, each designed for a fixed color. Today, however, customers want a greater variety of colors - VBG now works with five colors, two of which were previously applied without powder recovery. This resulted in high powder consumption and long color change times. With the new booth, color changes now only take three to seven minutes.

"The fact that we can now change colors quickly and recover the powder for all colors saves us around 1,500 kilograms of coating powder every year. This reduces our ecological footprint and cuts costs," explains Lars Pettersson, Production Manager at VBG.

The procurement process began last summer: three suppliers were invited to submit bids. In the fall, two of them carried out test coatings on representative components. In the end, VBG chose Wagner as its supplier.

"VBG decided to supplement the booth and guns with an IPS coating center to enable quick and easy color changes. IPS is a fully automatic powder center that ensures a constant supply of powder thanks to SFT (Smart Feeding Technology). In addition, VBG chose our energy efficiency package and combined it with a frequency-controlled post-filter motor - both together reduce the system's energy consumption," explains Johan Lanka from Wagner. The new cabin and all associated components were installed during the summer break. The project went smoothly and production was able to restart on schedule. "We had built up a buffer of critical spare parts as a precaution, but we didn't have to use them," adds Lars Pettersson.

VBG previously used tribocharged powder guns. These have now been replaced by electrostatic guns. "The new guns have significantly reduced the need for touch-ups. For example, we used to have to manually recoat the inside of U-beams to achieve the required coating thickness - this is now completely unnecessary," reports machine operator Robin Nyberg.

In addition to the booth and guns, Wagner also supplied an integrated powder system that enables improved process control and monitoring. "We now have much better control over the powder consumption per batch, which makes cost calculation much easier," adds Production Engineer Anna Edlund.

The plant in Vänersborg has two production lines - one for cast parts and one for laser-cut and bent sheet metal components. This production area is highly automated. Both streams converge in the coating area, where the throughput time is only 24 hours. Most of the components are automatically inserted into special fixtures in the processing cells by robots. After coating, the parts go directly to assembly - the most labor-intensive production step.

"Without our own coating, we could neither maintain the short throughput times nor guarantee reliable delivery dates. With this investment, we are ideally positioned for the future," summarizes Lars Pettersson (OM-4/26).