Waterborne alkyd anti-corrosion paint series is an indispensable coating in the paint and coating industry, providing corrosion protection to objects and extending their lifespan. While widely used, waterborne anti-corrosion coatings have certain drawbacks. Let's take a look at the defects of the waterborne alkyd anti-corrosion paint series, the reasons behind these defects, and potential solutions.
Common Defects in Waterborne Alkyd Anticorrosive Paint Series:
The advantages or disadvantages of the newly packaged anti-corrosion coating are not immediately apparent. Its appearance and stability can only be observed upon opening the cans and drums. Common defects include initials, sedimentation, surface floaters, and deteriorated fungi. Additionally, the coating's effectiveness can only be assessed after application. Potential issues may include paint flow, cap consistency differences, film shrinkage, pinholes, surface unevenness, insufficient richness of the external paint, and lack of luster. Over time, poor-quality anti-corrosion coatings or paint may exhibit defects such as cracking, peeling, blisters, and rust.
Common Causes of Defects in Waterborne Alkyd Antirust Paint Series:
The primary cause of foam control in coatings is the selection of defoamers and improper matching. During the pulping and painting stages, the defoamers did not evenly strike the scattered material. The paint viscosity was too low when using the roller brush, and the spray gun was not adjusted to its optimal state during spraying. There are foam holes, with no material in the empty areas, which are prone to invasion by aquaculture facilities, leading to corrosion.
2. The primary cause of coating shrinkage pores is the inability of the paint system's components to mix uniformly, with substances like emulsions having high surface tension and poor fluidity. Excessive amounts of defoamers, film formers, and other additives. More shrinkage pores lead to easier rusting of the undercoat and an unappealing paint finish.
The primary cause of hardness issues is related to the glass transition temperature (Tg) of the matrix and the amount of additive, as well as the intake and addition of powder. It is also influenced by the environmental conditions of temperature and humidity during the film-forming process. A coating that is too hard lacks flexibility, bendability, and impact resistance. Conversely, a coating that is too soft allows water penetration and plasticization, resulting in significant retention and corrosion effects.
4. The water resistance (salt spray) property is primarily due to the poor film-forming ability of the base material, inferior water resistance of the white color, and coarse solid particles. The base material is insufficiently added. The anti-rust emulsion does not actually rust. The surface tension of the paint is greater than that of the base material, leading to a decrease in adhesion between the primer and the base material. Fatal defects such as bubbles, shrinkage, and pinholes are present. Some paints contain the aforementioned defects, demonstrating resistance to water, saltwater resistance, and even resistance to salt spray.
5. The primary causes of coating appearance defects for exterior coatings include uneven film, insufficient fullness, high surface tension of the paint, internal non-flow, and uneven film surface. The lack of luster results in poor visual appeal, with high eye base or PVC content related to the base and pigment quality, and the bottom's flatness.
Common Issues and Solutions in Waterborne Anticorrosive Coatings
Drawing from our practical experience, we have implemented the following measures to prevent these defects. Specifically, we reduce the surface tension of the anticorrosive coatings. The distinction between water-based and solvent-based anticorrosive coatings lies in the different dispersing diluents, which results in varying surface tensions. Consequently, water-based coatings tend to have more issues than solvent-based ones. Therefore, for both high and low-grade water-based anticorrosive coatings, it is crucial to decrease the surface tension and enhance the adhesion of the coatings.
