New standard in surface technology
New system, improved quality: Goldhofer Aktiengesellschaft has optimized the process in the paint shop and now offers a completely new standard of surface quality with the eight-step Goldhofer 8S Painting System. That has been achieved by adding three process steps to the original five-stage process.
“At Bauma 2010, we presented new quality standards in surface technology following a radical change of production process. I am delighted that we have now moved forward again and are once more redefining our standards,” says Stefan Fuchs, CEO of Goldhofer Aktiengesellschaft.
The foundation for the new painting process is a further development of the two-component zinc dust priming system, which is superior to zinc spraying thanks to its outstanding adhesion properties and optimum edge cover and – with the high zinc content – offers active corrosion protection. “All that makes for easier repairs and a long service life,” says Production Manager Hubert Schaller. Goldhofer has once again confirmed its position as a technology and innovation leader in the vehicle manufacturing industry.
In the earlier production process, the vehicle frame and components were not painted until after assembly, which reduced the corrosion protection effect. That is now a thing of the past at Goldhofer: Following salt spray testing for 2000 hours (DIN EN ISO 9277) – which is unique in the vehicle manufacturing industry – there were some signs of underfilm corrosion with the zinc dust priming system. In the new production process, the frame is painted prior to final assembly of the various components, which guarantees paint penetration into the last nooks and crannies – for unbroken cover and continuous protection for the vehicle frame.
The individual steps in the 8S Painting System are carefully coordinated: The frame is sandblasted and three coats of paint applied: The two-component zinc dust primer, a two-component filler coat and a two-component top coat. The finished paintwork is not damaged during final weld-free assembly.
For the primer coat, Goldhofer now uses a high-grade zinc dust with a zinc content of 86% for maximum corrosion resistance. “This type of zinc dust primer is normally only used for offshore applications and bridges,” Hubert Schaller explains. The excellent adhesion properties offer optimum protection against mechanical impacts and thermal stress.
For the pipes, too, Goldhofer accepts no compromises and employs a closed system, with all components designed to the highest standard of corrosion protection. All hydraulic lines are electro-galvanized and coated, while all other connections and fittings have zinc-nickel surface protection (lamellar zinc). “That makes the pipes more resistant to mechanical impacts and aggressive media,” says the production manager. Another advantage: The galvanic coating is chromium-free. To ensure the best possible results with this system, the same high level of corrosion protection is applied to all hydraulic lines and fittings, i.e. pipes, pipe connections, hose fittings, pipe clamps and shut-off valves. For this purpose, the VOSS pipe connection system has been introduced. The Goldhofer pipe system was also subjected to salt spray testing and offers a C4 standard of corrosion protection pursuant to DIN 12944, corresponding to the requirements for chemical plants and swimming pools.
Since a chain can only be as strong as its weakest link, all the other hydraulic components have also been given this high standard of corrosion protection. The galvanized and passivated hydraulic lines are additionally finished with an organic protective coating, while the panels and covers are now either stainless steel or hot-dip galvanized.
Maintenance-free connection technology
Goldhofer also makes rigorous demands of the pipe connections.
“The hydraulics must satisfy stringent requirements to ensure an absolutely reliable, leakage-free and low-maintenance system that is equal to pressure peaks well in excess of maximum operating pressure and the mechanical loads imposed by oscillations, vibrations, etc. – whatever the operating conditions, including pronounced fluctuations in temperature,” says Hubert Schaller.
All this has been achieved through continuous further development of Goldhofer’s hydraulic connection technology in collaboration with the VOSS company. The result: “Our system represents the optimum available with current technology,” says the CEO. The advantage for production: The VOSSForm pipe-forming system offers maximum bending fatigue strength. Ease of assembly of the machine-produced pipe geometries completely eliminates the risk of human error during assembly.
In keeping with the Goldhofer quality concept, all outsourced components are genuine brand products from leading companies such as Bosch, Neumeister, BPW and RUD. They guarantee both certified quality and worldwide service support. All components and attachments are made of stainless steel or aluminum, or are hot-dip galvanized or powder coated.
Goldhofer 8S Painting System
The Goldhofer painting process comprises eight steps in accordance with the latest manufacturing process.
- Sandblasting pursuant to DIN SA 2.5
- Offshore-quality corrosion protection with 2-component zinc dust primer containing 86% zinc
- Joint sealing
- Colored 2-component filler coat
- Hollow cavity sealing with 2-component primer and top coat
- Finishing with 2-component top coat
- Protection for components with solvent-free and high-pressure-resistant materials
- Continuous salt-water-resistant protection