Polyaspartic coating for metal surfaces would be revolution in protective coatings. In general, coating systems on metallic surfaces usually include primer with the high solid content, as a first layer, and 3 to 5 layers (or more) of different coatings. Each layer is used in order to achieve a particular purpose. But in this coating, the number of layers has been reduced to maximum of two. The reason of reduction of the number of layers is to improve adhesion properties of first layer to the substrate, while still retaining excellent protective characteristics.
The polyaspartic coating (Eternal) is highly stable, hard and extremely resistant against weathering and abrasion.
Eternal applied directly to the carbon steel surface in a thin layer of 85 microns of dry film thickness showed excellent protection against chemical and mechanical damage.
According to the test results, Eternal reduces the number of layers to be applied compared to the conventional coating systems, has high resistance, ultra-low volatile organic compound (VOC) content (114 g L-1), and consequently reduces maintenance costs and environmental impact of the coating process.
COMPARISON WITH OTHER COATINGS
Table 1 demonstrates the results of the comparison of Eternal and the conventional protective coating systems for highly corrosive environments such as marine splash zones. As it can be seen, there is a huge difference in results. The VOC decreased significantly. In addition, the coverage of the coating was practically doubled comparing to other coating samples. The result of the immersion test after 10704 h and high impedance prove that the adhesion did not deteriorate, as the coating capacitance was almost constant, which is shown in Figure 7. The impedance range (logZ) was higher than 10 Ω cm2 proving that PA7 is a high-performance coating in comparison with other samples.
TABLE 1: COMPARISON OF SOME PROPERTIES OF ETERNAL AND CONVENTIONAL ANTI-CORROSIVE COATING SYSTEM
Sample A = Eternal (The improved polyaspartic coating (DTM))
Sample B = Polyaspartic coating (Conventional, DTM)
Sample C = Zn-rich Epoxy/Epoxy/PU
Sample D = Epoxy/Epoxy/PU