Two German companies partner to advance reefer manufacturing

Dec. 1, 2008
It Takes a lot of trust to commit well over $100 million to build a new state-of-the-art manufacturing plant to supply the needs of just one customer.

It Takes a lot of trust to commit well over $100 million to build a new state-of-the-art manufacturing plant to supply the needs of just one customer. Especially without any written contract.

But that is exactly what Brüggen Oberflächen und Systemlieferant GmbH did when it spent €75 million to build and equip its new refrigerated trailer manufacturing plant in Lübtheen, Germany.

The plant, currently ramping up production, manufactures one product for one customer. It specializes in manufacturing the Krone Cool Liner refrigerated trailer and its derivative, the Freshliner semi-insulated van. The customer is Fahrzeugwerk Bernard Krone GmbH, Europe's second-largest trailer manufacturer.

The new 403,650-sq-ft plant epitomizes that commitment. The Brüggen plant in Lübtheen will be the only plant where the Krone's new Cool Liner Duroplex steel refrigerated trailer will be produced. Highlights of the facility include a massive e-coat line that provides corrosion protection for the steel chassis on which the van rides, automated conveyor system throughout the plant, and custom fixtures that ensure maximum accuracy and efficiency of assembled products.

“All the truck-related products we manufacture are for Krone,” says Helmut Brüggen, director of industrial engineering and project management. “and we only deliver them for Krone.”

It's a co-dependent — and mutually beneficial — partnership. Brüggen shouldered the cost of building and operating the massive new manufacturing plant. By using this independent partner, Krone is able to keep its employment roll below the 2,000-employee threshold that would subject the privately-held company to an entirely new set of regulations — including corporate governance.

“Right now we can make major decisions in five minutes if we choose to do so,” says Jörg Sanders, sales manager for Krone. “The additional governmental requirements would make the process much more difficult. Our partnership with Brüggen allows us to be much more flexible.”

But Krone brings a lot to the partnership — virtually everything else associated with trailer manufacturing other than actually building the trailers. Krone designs the trailers, handles all marketing and distribution, and provides all customer service functions. The company also brought manufacturing engineering expertise, helping Brüggen implement much of the same production technology that Krone uses in its own facilities.

For brothers Bernhard and Helmut Brüggen, the commitment to Krone is simply the latest phase of a relationship that has been growing for more than 20 years. Their parents were farmers who also had a small forging operation. The forging operation produced a variety of products, including horseshoes. In the 1980s, Krone approached the couple about producing forged products for the company's agricultural implements division. The level of mutual commitment has grown significantly through the years.

Two-part ramp-up

Brüggen has moved quickly to get the plant operational. The company has only owned the property since 2006. During that period, Brüggen designed, constructed, and equipped the new plant while simultaneously setting up interim production in a kombinat, the term the former East Germans use to describe a manufacturing plant operating under the old communist system.

The plant produced its first prototypes in mid-2007 and its first production models in February 2008. The facility presently is turning out about 10 reefers per day. Capacity is 30 trailers per day when operating two shifts.

The way Brüggen opened the plant reflects the product that the plant builds. The Krone Cool Liner refrigerated trailer consists of two main assemblies — a van made of steel and foam sandwich panels and a steel chassis on which the box is transported. Although the van and chassis are two distinct assemblies, the Cool Liner is a conventional semitrailer, rather than a container and container chassis. The two components are produced in separate areas of the plant and then bolted together at the end of their respective assembly lines.

The plant became ready in phases. Van production became operational first. While Brüggen has been producing Cool Liners in Lübtheen since February, the box initially was the only part of the trailer built in the new plant. Until the 118,000-sq-ft chassis assembly area within the new building was completed this fall, Brüggen manufactured chassis in the konbinat.

With the new plant in operation, Brüggen plans to update the konbinat buildings for additional manufacturing capabilities.

What they wanted

The new plant was built with specific criteria in mind.

“Mr Brüggen planned the plant for modern process flow,” says Robert Weber, director of quality management. “He wanted minimal material movement and fast box production. It is very logical and state of the art. We feel it is the most modern refrigerated trailer plant in Europe.”

The result almost could be considered two plants under one roof — one for box production, the other for producing steel chassis. Yet the two production areas, each with material flowing in the same direction, meet seamlessly at the end of the building. There the two assemblies are bolted together into a single product.

For van production, the starting point is the area where coils of steel are stored. The coils are fed into a cut-to-length line where they are cut into lengths that correspond to the height of the van. Twelve such pieces are butted together and swaged to make a single skin for a sidewall.

Thyssen Krupp, a major steel producer, supplies the steel coils. To maximize the corrosion resistance of the steel, the surface is treated and coated to Krone specifications. The prepainted steel is exclusively white.

Two types of coils are used — prepainted white and primed steel. Coils of prepainted white represent the vast majority of the trailers produced at the Lübtheen plant. Custom colors are available, but they have to be painted on a special paint line at the Lübtheen plant using panels cut from coils that have been primed.

When two full-length skins have been produced, they are moved to the foaming station. There one skin is placed horizontally on the bottom of the foaming press while another is placed on the top. After foam is applied along the length and width of the skins, the two skins are held together under pressure until a tight, uniform bond is achieved.

The basic process is the same for floors, sides, roof, front wall, and doors. However, Brüggen has five foaming presses for these panels — one each for the left and right sides, one for the floor, and one for the roof. Doors share the same press as the front wall.

“This only makes sense,” Weber says. “The doors are the same width as the front wall.”

When they are ready to leave the foaming presses, the panels move to the adhesive station. There a two-part structural adhesive is used to bond the extruded aluminum rails to the panels. These, too, are placed in fixtures where they are heated and held under pressure.

Completed panels then move to their pre-assigned slot in a high-rise storage system. The storage system, which holds each panel flat, contains enough slots for 30 trailers — one day's production when the plant is at peak capacity.

Panels advance one additional step for assembly. With the floor positioned flat, the sides and front wall are lowered into place. A squaring fixture holds each panel in position until all can be welded together into a single assembly.

One of the highlights of the plant's new chassis assembly is the automated shotblast line. The Gietart blast equipment can clean assembled chassis to white metal in approximately five minutes.

The chassis move on edge through the shotblast machine in a continuous motion. Ten turbines in the blast unit fire a total of 4.5 tons of shot per minute. The shot is collected at the bottom of the booth, cleaned, and then reused.

“We have been using shotblasting to clean the surface since 1993,” Sanders says. “We started with our line of agricultural equipment and then added the technology to our trailer plants soon after that.”

Overhead conveyors move the chassis throughout the surface preparation process. A specially designed carrier transports three chassis at a time to the e-coat area and through the series of dip tanks that are required to apply the e-coat finish.

With the surface prepared, chassis move to the e-coat line. The line is long and deep enough to coat assembled 13½ meter (44' 3") chassis.

The e-coat process has a total of 16 tanks, including spare tanks that can be filled and used while other tanks are being cleaned.

Each tank holds approximately 200 cubic meters (52,834 gallons) of fluid. They are 16 meters long, 3 meters wide, and just over 4 meters deep.

As the chassis move toward the e-coat tank, the temperature rises to approximately 180° F.

“That causes a problem,” Sanders says. “We want to be able to move the chassis quickly from the e-coat line to powder coating. But we need to cool the chassis quickly because we have to apply the powder coat at room temperature.”

Chassis reach peak temperature in the tank containing the e-coat primer. To speed up the cooling process, Krone lowers the temperature of the remaining dip tanks so that the primed chassis are ready for powder coating once they leave the e-coat line.

It takes approximately an hour for a trio of chassis to move through the e-coat system.

The shotblast and e-coat lines occupy a major portion of the plant and can accommodate 10 chassis at a time on the conveyor system. At full capacity, the line can produce a chassis every 7½ minutes. Yet only 5-6 people are needed for the surface preparation department — including shotblast and e-coating operations. Production capacity for chassis exceeds that for vans. The reason for the difference is that the Lübtheen plant also will supply chassis for the Krone operation in Denmark. Only the Krone Duroplex steel version of the Cool Liner is produced in Lübtheen. The FRP version (with fiberglass skin instead of steel) is manufactured at the Krone plant in Denmark.

Brüggen was applying the final touches to its automated chassis assembly process when Trailer/Body Builders toured the plant in late September. The line has since swung into operation, but the photos shown on these pages depict an assembly line that Brüggen estimated was two weeks away from start-up.