Topic: Interdisciplinary product structure
CWA Construction SA
CWA Construction SA – Who are they and what products does the company make?
CWA Construction SA, headquartered in Olten, Switzerland, is part of the Doppelmayr Group. With its orbital, cable and aerial trams, people movers as well as special constructions in aluminium, CWA is the world's market leader. Their products are used in every climate zone around the globe.
What role does the surface quality play for these products?
Our customers demand the same kind of surface quality for their mountain cable cars and sky train cabins as would be required for car bodies. The paint quality therefore must be up to OEM standards in both optical as well as technical aspects. In addition, the operators also require a high level of sustainability, which of course affects the painting method, while aerial cable cars have special legal requirements regarding surface coatings.
What kind of requirements stem from this?
The paint system needs to be optimally set for the respective climate, i.e. the temperature and environmental conditions of the region where the product will be used. This means that the paint for people movers being used in the vicinity of a lake or ocean needs to have a very high level of resistance to salt water, whereas those employed in desert areas need to have coatings that can withstand major shifts in temperature and abrasive sand without showing wear on the surface. We put our products through numerous checks and tests, much like those used in the automotive industry, to ensure that they are prepared to handle whatever challenges they might face.
What painting procedures were used in the past at CWA?
In the past, all parts were subject to a wet painting process. About three years ago, we switched from a solvent-heavy paint mixture to a “very high solid” paint system. This also meant that we only needed one and a half cycles to provide a top coat instead of the previous two to three cycles. The entire process runs in such a way that the aluminium surface initially is given a corrosion-resistant primer and then a non-sanding filler as an intermediate layer with the top coat on top of that.
Why there was a thought about alternatives for surface treatment?
Due to the high utilisation levels, we had reached our capacity limits and wanted to further reduce our throughput times without negatively affecting quality. At the same time, we were looking to optimise costs and further reduce VOC emissions.
What alternatives were found that fulfilled this set of objectives?
One alternative would have been fully-automated coating. This would have required very high investment costs on the one hand, while on the other, we would have only been running the system at about 50% of capacity with our batch sizes of around 2,500 cabins per type. That is why we ended up staying with the conventional painting methods. Together with our paint partner DuPont CoatingSolutions, we looked which components could be powder coated. The results showed that components such as doors, suspensions and interior components were suited to being painted with the standard colour tone RAL 9006.
What was the decisive factor in choosing the interdisciplinary painting solution?
The crucial argument was that DuPont CoatingSolutions could demonstrate and guarantee that the powder coated parts would have an identical surface quality as those that went through the wet process, without showing any visible differences. Even the characteristics are comparable, as the powder coated surfaces can also be repaired, ground and polished. That had not been possible previously.
What advantages resulted from an environmental or financial perspective?
With the powder coating process, we work VOC-free and CO2 neutral. We also use far less material. The coating process can be done in about a third of the time it takes for the wet method. Powder coating some of the components has freed up capacity in our wet painting sector.
How was DuPont CoatingSolutions involved in the process?
In 2004, CWA searched for a new partner in the area of painting. We wanted a full-service provider for paint systems that would support us in implementing new technologies and happened on to DuPont CoatingSolutions. We quickly realised that we had a partner in DuPont CoatingSolutions that would take the time to intensively analyse our processes and also would provide the required know-how in the area of paint to enable us to continuously optimise these processes. DuPont CoatingSolutions has access to the full knowledge of the DuPont family and makes this information available to us and our suppliers. They even created a coating handbook for us and our suppliers, which contained the recommended system adjustments for each product’s operating conditions in order to ensure consistent quality. Our partner helps us to be always one step ahead. This includes very close communication with partners from the system and application technology sector as well as DuPont CoatingSolutions customers. We also do a mutual annual audit where we discuss possible changes as well as technical requirements for coating new products and/or materials.
What investments were needed to convert to this type of surface treatment?
Investments were not required, neither for our suppliers in the powder paint sector nor here with us. Our suppliers did however discover that they can gain new customers with the high quality with acrylic powder and achieved invested in a second coating line.
Do you see any further potential for optimisation in terms of environmental responsibility or financial efficiency in painting?
The next step that we are planning is coating with water-borne 2 component systems which will enable us to obtain further reductions in VOCs.
What kind of support do you expect from DuPont CoatingSolutions?
We expect DuPont CoatingSolutions to provide us with the technology as soon as it is guaranteed that we can apply it without setbacks in quality or a negative impact on production workflows.
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DuPont CoatingSolutions offers industrial coatings and automotive paint for all application areas, surfaces and substrates.
For more information, visit the website http://www.coatingsolutions.dupont.com