The powder symposium in Dresden opened the lecture season in the surface industry from February 8 to 9, 2024. According to the organizers, around 300 visitors and 180 users came to Dresden, and there were also many participants from Switzerland and Austria. The industry exhibition was also well booked with 50 exhibitors and was a popular point of contact for those interested in the individual topics, and not just during the breaks.

20 presentations and several panel discussions

Sustainability, energy efficiency and the CO2 footprint were very much to the fore in many of the presentations, even more so than in previous years. For example, the presentation of a new powder coating system at the contract coater NanoCoat, which was only founded in 2022, showed interesting possibilities of today's system technology and control in this regard - read the detailed article from page 20 in this issue. A wide range of measures were implemented here, from a pre-treatment tunnel made of polypropylene pre-treatment to low-temperature chemistry and low-temperature powder coatings through to comprehensive digitalization of the plant.

The energy concept with comprehensive heat recovery and hybrid burners that can run on both electricity and gas is also state-of-the-art. There are also plans to use hydrogen in the future. A discussion about the project with Managing Director Florian Chlupka, Lukas Licher from EBS Licher and Andre Berse from DOK-Chemie can be found in the video report. A new coating system on two levels was also presented at Warema, a renowned manufacturer of sun protection systems. The levels are connected by elevators and the VarioFT system is used as the conveyor technology. A friction wheel drive system ensures high flexibility in terms of process times and prioritization.

A modern MES system from Rippert, specially adapted to the user, is superordinate to this. Driverless transport systems (DTS) are also part of the concept, which transport the components from the production stations to the coating system. This ensures a very high level of flexibility, as it is possible to re-sort, buffer or bring forward orders at any time. Another application example was the Aabo-Ideal coating system in what is probably the most environmentally friendly furniture factory in the world, "The Plus" by Vestre. Located in the middle of the forest, the factory combines sustainability with industrial efficiency in an iconic way

However, if scrap is used that has not been separated by type, the resulting cast materials contain high levels of zinc and copper. The FEM has established that these enrichments can have a negative effect on the corrosion properties under certain circumstances, but not in all cases.

This is because there are many recycled aluminum alloys that work well in pre-treatment and coating. However, it is difficult to find this out in advance. Even if companies have an XRF gun to determine the alloy, it is important to bear in mind that the measuring beam from the gun always penetrates into deeper layers of the material and cannot just measure the surface. The result of such a measurement is therefore an average value that does not allow a precise statement to be made about the increased concentration on the surface.

Project start for pre-treatment process development

The FEM has therefore started a project together with the company Nabu to develop a pre-treatment process that compensates for precisely these fluctuations and is able to dissolve the critical alloy components from the surface. This is because it no longer matters what the concentrations of critical elements are on the surface of a recycling alloy if these are removed, thus ensuring that the conversion layer can always be reliably formed. The project will run for another one and a half years and Dr. Langer is confident that it will be possible to present a usable solution at the end of this period.

Sustainability topics and_{CO2 footprint} remain in vogue

A number of other presentations dealt with the topic of sustainability and resource conservation. On the one hand, Kluthe discussed the determination of the_{CO2 foot}print for coating companies and, in this context, highlighted the advantages of thin-film pre-treatment compared to low-temperature zinc phosphating. This reduces process costs by more than twelve percent compared to standard zinc phosphating. In contrast, thin-film pre-treatment can even reduce costs by at least 20 percent.

Thomas Querfurt from HangOn illustrated how the_{CO2 footprint}, energy consumption and operating costs can be significantly reduced by optimizing the suspension of the components. The more air there is between the components in the hanger, the longer the system has to run to coat the same area. Using calculation examples, he showed that energy savings of up to 90 percent and a 50 percent reduction in the_{CO2 footprint} can be achieved with an optimized suspension system. In the video post-report you will find an interview in which Querfurt discusses the key factors of good part suspension and suspension devices.

Also on the agenda in Dresden were possible energy savings in the maintenance and treatment of active and rinsing baths using evaporators, as well as several panel discussions on potential savings in terms of energy and operating resources. The influence of pre-treatment chemistry on distillate quality in vacuum distillation was also discussed.

Dr. Ju-Young Uam from Chemetall dealt with the digital recording and analysis of pretreatment processes in connection with powder coating, with a focus on the reduction of_{CO2 emissions}. Due to the wide range of influencing factors, Uam recommends a systematic, iterative approach and working out improvements step by step rather than hoping to solve all problems at once with a big bang.

Factors influencing the fatigue of painting hooks

An unusual topic was raised by a presentation on the load-bearing capacity of suspension systems. Frank Brünnig from Emptmeyer dealt with the conditions under which a painting hook fails and whether and under what conditions it can be expected to bear more than its nominal load.

He also presented fatigue tests. These show that the shape of the hook has an influence on the load capacity, but that heating in the oven to around 200°C does not. In summary, he made it clear that savings of up to 50 percent are possible by choosing the optimum diameter - because oversized suspension devices cost material and paint stripping effort and transport heat out of the ovens unnecessarily.

As an independent insurance broker, Sven Hoffmann dealt with the correct drafting of contracts with clients for powder coaters, particularly from the perspective of product liability insurance, and provided interesting and important aspects that coaters usually neglect in their everyday work.

An alternative to hot-dip galvanizing?

The presentations concluded with the presentation of a corrosion protection system, a so-called cold galvanizing with a powder coating as an alternative to hot-dip galvanizing of steel substrates. The three project partners were Vestocor, a manufacturer of sophisticated corrosion protection systems, Dr. Herrmann GmbH as a testing institute and Lackierzentrum Reichenbach, which carries out painting orders for customers in the military, railroad, marine, aviation and energy technology sectors. Among other things, test results were presented with different paint systems after 720 hours of NSS (C4) and 1440 hours (C5), including with a new epoxy-based primer.

The results show that significant improvements are possible with optimized zinc flake and zinc dust primers compared to conventional primers. In conclusion, the organizer reported very positive feedback and was pleased to see how many possibilities and concepts were discussed to make powder coating more energy-efficient and resource-saving. You can also find his closing statement in the video report