New procedure for the assessment of coating systems developed

Waterbased coatingsystems need improvement in short-term tests Source: Pixelio/Maren Beßler

Waterbased coating substances are known to perform poorly in short-term tests such as the salt spray test, although they display good reliability and anticorrosive properties when exposed to natural weathering. Therefore, the industry is highly interested in innovative assessment procedures of these coating systems that allow an unbiased comparison with other systems. The prime weakness of waterbased systems in short-term tests is due to a specific slowed film formation and the fact that the complete barrier effect of the coating is developed only after hydrophilic components have been washed out. In the course of this project a quantitative the Fraunhofer IPA developed a rapid test that allows reliable statements about the protective abilities of waterbased coating systems. This enables scientists to directly compare different coating systems without having to wait for the formation of the complete barrier effect. To do that, the examined coating systems have been tested immediately after conditioning and after the formation of the complete barrier effect, which can be accelerated tenfold by using a device for humid/dry cyclization at 75 degree Celsius. This compensates the disadvantage of waterbased systems compared to other systems.