The Germany based wfk - Cleaning Technology Institute e.V. conducts research within the realm of cleaning and disinfection of hard surfaces. In order to find ways to save energy, water and reduce chemicals, not only already established processes are under optimization but also new methods operating without water and without chemicals such as cleaning with plasma are being devised. Apart from effectiveness and resource saving, another major focus of the research is to attain cost efficiencies.
Recent successfully completed research activities with Openair-Plasma® included a project dealing with graffiti removal. Modern day graffiti artists have over 100 different types of spray paint at their disposal for leaving their “public signatures”. In Germany alone, the effort taken and the costs incurred through removal of the damage caused by graffiti amount to several hundred million Euros each year.
The objective of the research project was to find out whether atmospheric pressure plasma can replace the conventional cleaning methods such as water spraying, high pressure water jetting, water particle jetting or the application of chemical substances applied to building facade substrates.The substrates used for testing included bricks, sandstone, fine stoneware, marble, granite, eloxal and stainless steel.
The plasma is applied through a rotary nozzle of type RD1004 through which the plasma hits the building surface with almost ultrasonic speed. The impact causes the sprayed-on paints to evaporate. Openair-Plasma®, unlike the other noted conventional processes, does not endanger the building material itself.
The use of Openair-Plasma® provides building cleaners with an effective tool for chemical- and wastewater-free and material-saving building facade cleaning.