Growth on ship hulls (fouling) causes enormous ecological and economical drawbacks within the marine sector. Additional fuel consumption of up to 40 % as well as increased emission of environmentally harmful greenhouse gases depicts only some negative aspects within this context. To prevent fouling, ship hulls are usually coated by antifouling paints which contain toxic substances. These biocides are continuously released from the paints and kill therefore attached organisms.
Until 2008, the biocide TBT was very common due to its high efficiency. As it was shown already several years before that TBT has severe consequences on marine livings, the resulting prohibition caused an increasing demand for alternatives. In this context, it can be expected that prohibitions comparable to the Lake Constance, where the utilization of toxic paint is completely forbidden, will also arise in other places. Another big impact will occur when the new EU-biocide-regulation becomes valid in 2019. This regulation not only prohibits almost all biocide substances existing on the market, in addition it includes the ban of landing in EU-harbors.
Due to these reasons, the need for a biocide-free alternative is highly increased during the last years.
Phi-Stone AG develops a biocide free coating in close cooperation with the faculty of engineering of Kiel University. The concept of this coating includes the development of an extremely smooth and extremely robust surface which inhibits growth, allows easy cleaning and protects the hull from biocorrosion.
The base is given by a solvent-free two-component polymer system (PTU) which is modified by special ceramic filler particles (CSP - Core Spike Particles) in order to get the necessary mechanical stability. This composite (CSPC) can be applied by roll or spray-technique.
As the aim of the project involves the simple removal of growth from the surface, development of test stands which can evaluate the cleaning-behavior of the coating depict another content. The laboratory-scale will be represented by a flow-passage. Here, an integrated force-sensor will give information on the shear force which is necessary in order to clean the sample-surface.
For field-test evaluation, a dynamic test-stand will furthermore be developed. This stand consists of several sample-holders which can be accelerated to up to 8 knots by an electric engine. Here, the long-term behavior of the samples can be evaluated under natural conditions. In addition, the cleaning-behavior of the samples can be tested under simulated movement through water.
As the project partner Wilckens has wide-reaching contacts within the maritime sector, it will also be possible to place samples on test areas all over the world which can show the growth behavior under different climatic conditions.
The development of a partial-automated application-technique will be implemented by the project partner Teyfel Automation. Aimed by this technique, it will be possible to coat large areas even on bended surfaces like ship hulls.