Wood or glass Plastics and aluminum – who can create effect finishes such as chrome effects or give chrome-plated parts new, mirror-like sheen, have great potential. However, this only applies if the shine is permanent. A recurring problem in the production of chromium-like surfaces is namely that long-lasting protection against yellowing, matting or infiltration of the wafer-thin mirror layer was difficult to guarantee – especially not when the surfaces sun exposure, weathering and mechanical influences are exposed. All the more surprising that a chrome spray system for chemical spray metallization, CSM short, which has presented the company Verchromen24 S.L now apparently met extensive quality tests. “Originally, chemical spray metallization was developed as a cost-effective alternative to real chrome plating,” explains Verchromen24 SL Managing Director Ulrich Kuitkowski. “In the meantime, this process of effect painting by the development of fully automatic coating systems on an industrial scale represents a technically mature solution.” System of chromium paint with the existence of climate change tests such as the so-called Florida and the Arizona test and the trouble-free completion of a 1000-hour salt spray test. “Among other things, by adding UV inhibitors, we have optimized the CSM system-specific clearcoat so that we can also guarantee UV resistance,” adds Kuitkowski. “The Chrome system thus fulfills the decisive DIN-EN-9227 standard for the automobil industry.”
Good practice
The processing of the robust Chrome system basically corresponds to the usual procedure in spray metallization: A transparent primer (base cod) is first applied to the surfaces to be metallized. It is extremely important that the parts on the surface are clean and free of grease. The painting should be done in dust-free rooms. An important point is the attachment of the parts to be refined on holding devices. Which type of holding device is suitable for the respective part depends primarily on the size and shape of the objects. On the one hand, the primer provides the perfect smooth surface for the subsequent metal layer, on the other hand, it is characterized by good wettability and absorption capacity for water. The primer (base cod) must be dried very carefully – optionally 60 to 150 minutes in the dryer at 60 to 90 degrees or 48 to 60 hours at room temperature.
The next steps follow each other directly. First, you start to inject a so-called activation solution on the parts to be refined. The activation process takes place until a closed film of water forms on the surface, which is thus made receptive to the subsequent chemical metal precipitation. Immediately after activation, a wash with ionized water occurs. The excess activating solution is washed out thoroughly. Then it is metallized with a special two-component gun. From one gun nozzle while silver salt, sprayed from the other nozzle reduction solution. Both jets mingle outside the gun at a certain angle. When the two beams meet, the chemical reaction and, consequently, the metal precipitation begin. The metal film builds up extremely evenly and quickly. The spraying time is 30 to 60 seconds. Then rinse thoroughly with water again, so that the chemical residues are removed from the objects.
Clearcoat (topcode) gives protection
Then dry the freshly metallised parts with warm air, if possible, to avoid water spots. The chemical metallization is complete. Finally, the sensitive metal layer must be protected against chemical and physical influences with the CSM clearcoat (topcode). “With the CSM technology, we can metal parts of any size and shape,” sums up Ulrich Kuitkowski. “Suitable substrates are plastic and metal, but also wood or glass.” This makes it clear for which markets the process comes into question: from trade fair construction and advertising to vehicle tuning and refinement through to the classic car scene. The advantage: Due to the stability and robustness of the coating, it is no longer necessary to distinguish between indoor and outdoor applications. Ulrich Kuitkowski: “The DIN EN 9227 standard gives us little room for maneuver: if applied properly, there must be a five-year guarantee for preserving the surface – at least.”
