Painting equipment matters

Stera's factory in Paimio, Finland systematically develops its production with the aim of boosting the efficiency of the powder coating paint shop and improving quality.

Stera Technologies is a global company specializing in contract manufacturing of mechanics and electronics. In addition to its sites in Finland, the company has production plants in Estonia and India. Stera's factory in Paimio specializes in manufacturing electrical enclosures and 19" cabinets, as well as subcontracted ventilation and other customised sheet metal assemblies.


"Our largest customers – ABB, Vaisala, Kone, Ponsse, and Sandvik – are global operators who demand high surface quality for their products," says Jarmo Rantahalvari, Stera's Production Manager.

Teknos is Stera's largest paint supplier, and it has been involved in the company's operations from the very beginning. "Having our own paint shop is a strength – it enables us to serve our customers more quickly and cost-efficiently," says Rantahalvari.

"We have collaborated closely with Teknos and our partnership has worked very well. Teknos' extensive product and color range and rapid deliveries help us to meet our customers' requirements. We also receive advice and technical support whenever we need it. We are very happy to receive service like this," says Kirsi Nurmisto, Stera's Sourcing Manager, who reserves praise for Niko Skytten, Teknos' Sales Engineer.


Problem and solution

Cabinet structures are challenging in terms of coatings. "The problem areas are the internal corners and folds of enclosure structures – it is difficult to get paint to accumulate in these areas. Painters have needed to spray a very large amount of paint, and some of the powder that misses the target then builds up in the outer corner and on the edges, leaving a layer of paint that is too thick. This has caused runoff and leveling problems around the edges of items," says Niko Skytten from Teknos.

The equipment supplier was able to solve the problem. "Using a new spray gun model supplied by Spraytec and less air, it is possible to evenly spray powder coating, even in tight structures, and there is no runoff," Rantahalvari says. "The new spray gun is also easier to use and handle, and colors can be changed very quickly," he adds.

We are very happy to receive service like this.

The painters are also happy with the new Spraytec spray gun. "It took a while before we got used to using the new spray gun. Now difficult corners are significantly easier to paint," says Stera's Jari Mamia, who is responsible for the process and has more than 16 years' experience in powder painting.

"You might not want to hear this"

Painting equipment is very important, both in terms of the painting process and the outcome of surface treatments. Nordson's high density, low velocity (HDLV) technology supplied by Spraytec has been very helpful for Stera.

"When powder coatings are applied to items using less air, painting becomes more efficient.
In terms of quality, the more standardized parameters, the better. This includes factors such as maintaining the same settings and using the same amount of powder," says Jarno Mäkeläinen, Spraytec's Sales Manager.

"As paint manufacturers, you might not want to hear this, but our spray system also reduces the consumption of powder coating," Mäkeläinen adds.

Teknos is not at all worried about this – quite the opposite. What is good for customers is always good for paint manufacturers in the long run.

STERA Smart Factory

Stera Smart Factory is a real-time monitoring system that enables processes to be systematically measured and made more efficient. Production development work is often a long process because nobody wants to jump into the unknown without first studying existing practices.

Systematic development work at Stera's own paint shop began in spring 2016 with the aim of boosting the efficiency of the paint shop and improving quality. The project's dynamo was Janne Alatarvas, who was carrying out his thesis project for Stera.

"Stera's wide range of products creates challenges in terms of developing appropriate parameter indicators for the painting process, but it also makes research work interesting," Janne Alatarvas says.

In the picture (left to right): Juha-Matti Verho, Jarmo Rantahalvari, Jarno Mäkeläinen, Kirsi Nurmisto, and Niko Skytten. 

"We now have a good opportunity to develop our own operations and apply the Smart Factory concept to the development of our own paint shop. Production has been monitored by means such as deploying sensors and recording production using a camera," Jarmo Rantahalvari says.

"We are first collecting data, examining paint consumption, and visualizing the process parameters in the paint shop. Next spring, we will probably be able to present tangible results," Rantahalvari says.

Nordson HDLV - high density, low velocity

HDLV pumps consist of two adjacent two-part chambers that pump powder into the powder hose in turn. This ensures that a constant volume of powder and air is always sent into the powder hose in turn. The HDLV pump prepares the powder dose using less compressed air, which reduces the number of vortexes in the air flow and decreases the velocity of the powder. HDLV pumping technology provides the following advantages:

  • Better chargability of the powder coatings and better operating efficiency
  • Powder application with 1/3 of the amount of air in comparison with injector systems
  • Rapid color changes
  • Even and repeatable film thickness
  • Painting of difficult sites improves. The sprayer can be placed almost onto the item because the compressed air will not blow the powder away.

Stera Technologies Oy

  • Established in 2007 as a result of the merger of Elektromet Yhtiöt Oy, Hihra Oy, Levyosa Oy, Aumec Systems Oy, and Beertekno Oy – companies that had been operating in the sector for a long time.
  • A privately owned company, operating globally and specializing in contract manufacturing of mechanics and electronics.
  • Contract manufacturing tailored for each customer, with the process covering design, prototypes, component manufacture, assembly, testing, and related tools.
  • 55,000 m² of production space
  • 7 factories
  • 750 employees
  • STERA Smart Factory is a real-time monitoring system that enables processes to be systematically measured, monitored, and made more efficient.

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