Measurement of Adhesion Properties Between Topcoat Paint and Metallized/Galvanized Steel with Surface Energy Measurement Equipment

摘要

The objectives of this research project are: (1) Compare the adhesion properties of NEPCOAT-approved topcoat paint over metallized or galvanized steel. Use surface-energy measuring technique to characterize the wetting properties of the liquid paint on the profiled zinc surfaces. Explore correlation between the adhesive strength and the liquid paint wetting properties. As control the adhesion properties of topcoat paint over zinc primer painted steel substrates will also be measured. (2) Investigate various factors affecting the adhesion of topcoat paint over galvanizing. (3) Report and recommend practices that produce the best adhesion of NEPCOAT-approved topcoat paints over metallized and particularly galvanized steel surfaces. We prepared four different types of test panels coated with five different commercial paint systems. The paint systems include four systems adapted from the NEPCOAT list of intermediate and top paints qualified for bare steel, and one system of epoxy sealer for metallized surface. Four types of substrates were used for fabricating the test panels: (1) galvanized steel with mechanical grinding to produce rough surface, (2) galvanized steel with blast profiling to produce rough surface, (3) galvanized steel stored indoor for two weeks before blast profiling and painting, and (4) metallized steel with inherent roughness due to the thermal spray process.